Notices
Page 1 of 2 12 LastLast
Results 1 to 100 of 102

Thread: Why Fukushima Reactor So Close to the Sea?

  1. #1 Why Fukushima Reactor So Close to the Sea? 
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Given that Japan is probably one of the worst areas on the globe for tsunamis, why was the Fukushima nuclear reactor built so close to the sea?

    The reactor was badly damaged by the 30 metre wave and being right on the shoreline it would have received the full force of the breaking wave.

    Surely it would have made a lot of sense building such a reactor on higher ground of which there is plenty in Japan's interior?




    Reply With Quote  
     

  2.  
     

  3. #2  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,325
    It is close the coast:
    http://maps.google.com/maps?hl=en&ta...r%20reactor%20

    Notice the two breakwaters though, so it probably didn't get the full force.

    I'm not sure the problem were cause it much be direct damage, as the lack of external power for days and days. Yet still we probably both wondering if the back up systems such as batteries and generators were left untarnished by the wave.


    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  4. #3  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    I believe the tsunami was 33 feet, not 33 metres. Nevertheless, a wave of this height was apprently not among the design criteria. One news report mentioned that the backup diesel generators were located in a pit, so that any water overtopping the seawall would have ended up flooding them. With hindsight this seems like a dreadful mistake.
    Reply With Quote  
     

  5. #4  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,325
    There are some advantages to keeping it close to the sea as well including flat terrain to build on, available water for cooling or heat exchange, and in a worse case scenario most radioactive particles would go with the prevailing Westerlies out to sea.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  6. #5  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by Lynx_Fox
    It is close the coast:
    http://maps.google.com/maps?hl=en&ta...r%20reactor%20

    Notice the two breakwaters though, so it probably didn't get the full force.

    I'm not sure the problem were cause it much be direct damage, as the lack of external power for days and days. Yet still we probably both wondering if the back up systems such as batteries and generators were left untarnished by the wave.
    I believe that's Fukushima Daini which did not have a problem. It's a little later vintage. Fukushima Daiichi is north of there. I thinke Fukushima Daiichi 1 went on line in 1970 whereas Fukushima Daini started in 1981.

    The emergency power was apparently only available for about an hour. Either the diesel generators or the emergency switchgear got swamped out by the tsunami.

    The tsunami seems to have exceeded the plant's design basis. It's the biggest earthquake ever in Japan.
    Reply With Quote  
     

  7. #6  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Lynx_Fox
    It is close the coast:
    http://maps.google.com/maps?hl=en&ta...r%20reactor%20

    Notice the two breakwaters though, so it probably didn't get the full force.

    I'm not sure the problem were cause it much be direct damage, as the lack of external power for days and days. Yet still we probably both wondering if the back up systems such as batteries and generators were left untarnished by the wave.
    The Google map you quote gives a misleading impression as to the immediate terrain.

    From television news pictures the plant is almost sitting on the shoreline and the "breakwaters" are very low indeed and would only stop storm waves at most.
    Reply With Quote  
     

  8. #7  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Lynx_Fox
    There are some advantages to keeping it close to the sea as well including flat terrain to build on, available water for cooling or heat exchange, and in a worse case scenario most radioactive particles would go with the prevailing Westerlies out to sea.
    Can you use seawater for cooling?

    Seawater is highly corrosive
    Reply With Quote  
     

  9. #8  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by galexander
    Quote Originally Posted by Lynx_Fox
    There are some advantages to keeping it close to the sea as well including flat terrain to build on, available water for cooling or heat exchange, and in a worse case scenario most radioactive particles would go with the prevailing Westerlies out to sea.
    Can you use seawater for cooling?

    Seawater is highly corrosive
    Yes. You wouldn't put it in the reactor. There is a closed steam/feedwater loop that uses fresh water. The service water (sea water) would go through the condenser.
    Reply With Quote  
     

  10. #9  
    Forum Freshman
    Join Date
    Mar 2011
    Posts
    7

    Come on people you must have some more opinions about Fukushima disaster? Whats happening there? whats damaged? what should be fixed? how it should be fixed? what are consequences?

    This is huge unfortunate disaster with an huge affect to human race! Please discuss and bring this up.
    Reply With Quote  
     

  11. #10  
    Forum Freshman
    Join Date
    Mar 2011
    Posts
    7
    I just registered because was searching for soem Fukushima conversations and this thread came up as the only one on the first page of google search for Fukushima forum.. and it was only 7th link from the top! :O

    I mean we are facing enormous nuclear incident here with possibly much worst to come and where are people talking about it?? This is affecting much more than just Japan and I think that much more nations should be involved and taking initiative. Especially after a week is passed already and Japanese officials are struggling to cool faulty reactors.

    My opinion is that Japanese officials are a bit lost on this scale of disaster- I respect they efforts ofcourse but they clearly would need few braniacs more to actually start doing something more concrete than pouring water from helicopters which are waaay too high above! Very bad backup plans and preparations and, honestly, lack of courage! For f*** sake if you can't handle it neatly and "by procedures" then threat it as WAR and put some man down there with the tools and bags of ice to cool that hot bitch down! How hard could it be to reconnect power supply?? or to install new diesel generators? if that would be my neighborhood , I would volunteer and would prefer to die in an hour, knowing that millions others could be saved, than getting radiation in few days or few years!

    I m not exaggerating, am I?
    Reply With Quote  
     

  12. #11  
    Forum Freshman
    Join Date
    Mar 2011
    Posts
    7
    Fukushima nuke crisis - Chernobyl on steroids
    http://www.youtube.com/watch?v=R7JvuUwpq40

    I so agree.. too slow respond on such a serious disaster.. apocalyptic situation
    Reply With Quote  
     

  13. #12  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by hubis
    I m not exaggerating, am I?
    Yes, I think you are. It's not going to be anywhere near the scale of Chernobyl. I don't think there will be any radiation related deaths, and no other countries will be affected.
    Reply With Quote  
     

  14. #13  
    Forum Freshman
    Join Date
    Mar 2011
    Posts
    7
    The Google map you quote gives a misleading impression as to the immediate terrain.

    From television news pictures the plant is almost sitting on the shoreline and the "breakwaters" are very low indeed and would only stop storm waves at most.
    yep, how that could stop tsunamis? http://www.tepco.co.jp/nu/f1-np/camera/index-j.html
    Reply With Quote  
     

  15. #14  
    Forum Freshman
    Join Date
    Mar 2011
    Posts
    7
    Quote Originally Posted by Harold14370
    Quote Originally Posted by hubis
    I m not exaggerating, am I?
    Yes, I think you are. It's not going to be anywhere near the scale of Chernobyl. I don't think there will be any radiation related deaths, and no other countries will be affected.
    but mate, 4 plants are faulty, four reactors are in danger.. thats worst than ever before.. dunno.. lets hope they fill those pools with enough water today and electricity back too
    Reply With Quote  
     

  16. #15  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by hubis
    Quote Originally Posted by Harold14370
    Quote Originally Posted by hubis
    I m not exaggerating, am I?
    Yes, I think you are. It's not going to be anywhere near the scale of Chernobyl. I don't think there will be any radiation related deaths, and no other countries will be affected.
    but mate, 4 plants are faulty, four reactors are in danger.. thats worst than ever before.. dunno.. lets hope they fill those pools with enough water today and electricity back too
    At Chernobyl there was no containment building. The core was filled with carbon moderator which caught on fire, sending a huge fireball into the air, carrying large quantities of fission products. There is no such mechanism at Fukushima to send that amount of material into the air.
    Everyone seems to be focusing on the nuclear plants, which haven't killed anybody yet, as far as I know. Meanwhile the tragedy of people over there freezing in the cold without any food is being largely ignored.
    Reply With Quote  
     

  17. #16  
    Forum Freshman
    Join Date
    Mar 2011
    Posts
    7
    Quote Originally Posted by Harold14370
    At Chernobyl there was no containment building. The core was filled with carbon moderator which caught on fire, sending a huge fireball into the air, carrying large quantities of fission products. There is no such mechanism at Fukushima to send that amount of material into the air.
    well thats some positive info, cheers

    Quote Originally Posted by Harold14370
    Everyone seems to be focusing on the nuclear plants, which haven't killed anybody yet, as far as I know. Meanwhile the tragedy of people over there freezing in the cold without any food is being largely ignored.
    thats lame from such a wealthy country as Japan is but I m sure the most people will survive with that little food and fire they manage to get.. human body and mind are amazingly resistant.. elder ones could be in trouble especially if missing certain medicines
    Reply With Quote  
     

  18. #17  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Harold14370
    Quote Originally Posted by galexander
    Quote Originally Posted by Lynx_Fox
    There are some advantages to keeping it close to the sea as well including flat terrain to build on, available water for cooling or heat exchange, and in a worse case scenario most radioactive particles would go with the prevailing Westerlies out to sea.
    Can you use seawater for cooling?

    Seawater is highly corrosive
    Yes. You wouldn't put it in the reactor. There is a closed steam/feedwater loop that uses fresh water. The service water (sea water) would go through the condenser.
    Please explain why the steam needs to be condensed
    Reply With Quote  
     

  19. #18  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,325
    I had a simpler heat exchanger in mind.

    From the reports they did resort to using actual sea water in at least one of the reactors or cooling ponds for emergency cooling.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  20. #19  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Quote Originally Posted by galexander
    Please explain why the steam needs to be condensed
    Thermal energy is converted to mechanical energy through the Rankine cycle. The mechanical energy drives the electric generators.

    In a power plant the Rankine cycle uses water in a closed circuit. Water is boiled to produce high pressure steam that drives the turbines. The steam leaves the turbines at very low pressure having given up most of its energy driving the turbines. Since it is a closed circuit the low pressure steam has to be returned to the boiler which operates at much higher pressure, so it must be condensed in a heat exchanger, then pumped back up to the high pressure of the boiler. The heat exchanger is called a surface condenser; the pump is the boiler feedwater pump.

    If you did not condense the steam you would have to vent it to atmosphere and then you would have two problems:
    a) You would need a source of huge amounts of very clean water. This is completely impractical.
    b) You would have to vent the steam at atmospheric pressure, instead of at a few inches of mercury vacuum, which greatly reduces the efficiency of the turbines.
    Reply With Quote  
     

  21. #20  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by Lynx_Fox
    I had a simpler heat exchanger in mind.

    From the reports they did resort to using actual sea water in at least one of the reactors or cooling ponds for emergency cooling.
    Yes they did, because they had no power to operate the normal cooling system. This pretty much trashes the reactor for any future use.

    The Fukushima reactors are boiling water reactors where the water boils in the reactor vessel. A pressurized water reactor has even a third loop. The boiling in a PWR occurs in another heat exchanger called a steam generator.
    Reply With Quote  
     

  22. #21  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    Quote Originally Posted by galexander
    Please explain why the steam needs to be condensed
    Thermal energy is converted to mechanical energy through the Rankine cycle. The mechanical energy drives the electric generators.

    In a power plant the Rankine cycle uses water in a closed circuit. Water is boiled to produce high pressure steam that drives the turbines. The steam leaves the turbines at very low pressure having given up most of its energy driving the turbines. Since it is a closed circuit the low pressure steam has to be returned to the boiler which operates at much higher pressure, so it must be condensed in a heat exchanger, then pumped back up to the high pressure of the boiler. The heat exchanger is called a surface condenser; the pump is the boiler feedwater pump.

    If you did not condense the steam you would have to vent it to atmosphere and then you would have two problems:
    a) You would need a source of huge amounts of very clean water. This is completely impractical.
    b) You would have to vent the steam at atmospheric pressure, instead of at a few inches of mercury vacuum, which greatly reduces the efficiency of the turbines.
    I am going to dispute your science for the simple reason of the image below:





    This is the Karlsruhe nuclear power station in Germany.

    And I see loads of steam coming from the chimneys.

    Clean water CAN be found in rivers and lakes for producing the steam and it CAN be filtered. How CLEAN does it have to be?

    Any reduced efficiency of the turbines is going to be counterbalanced by the reduced efficiency resulting from pumping water into a condenser and then the pumping of the condensed water back into the system again.

    And how does steam lose pressure having passed through turbines?

    Are you sure about that?
    Reply With Quote  
     

  23. #22  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by galexander
    This is the Karlsruhe nuclear power station in Germany.

    And I see loads of steam coming from the chimneys.

    Clean water CAN be found in rivers and lakes for producing the steam and it CAN be filtered. How CLEAN does it have to be?

    Any reduced efficiency of the turbines is going to be counterbalanced by the reduced efficiency resulting from pumping water into a condenser and then the pumping of the condensed water back into the system again.

    And how does steam lose pressure having passed through turbines?

    Are you sure about that?
    Those are called cooling towers. They are not boilers. They cool the river water before it gets put back into the river, so you don't kill the fish.
    Let's see your thermodynamic calculations to prove your statement about the reduced efficiency.
    Steam loses pressure as it passes throug the turbine, because condensed steam takes up less volume. It is the difference in pressure that makes the steam pass through the turbine. No pressure drop = no power generated.

    How clean does it have to be? Well consider that when you boil water, any minerals and dirt in the water are left behind. Your boiler would fill up with dirt in minutes. If you ever get a chance, take a look inside the basin of one of those cooling towers. It's probably full of mud.
    Reply With Quote  
     

  24. #23  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Harold14370
    Quote Originally Posted by galexander
    This is the Karlsruhe nuclear power station in Germany.

    And I see loads of steam coming from the chimneys.

    Clean water CAN be found in rivers and lakes for producing the steam and it CAN be filtered. How CLEAN does it have to be?

    Any reduced efficiency of the turbines is going to be counterbalanced by the reduced efficiency resulting from pumping water into a condenser and then the pumping of the condensed water back into the system again.

    And how does steam lose pressure having passed through turbines?

    Are you sure about that?
    Those are called cooling towers. They are not boilers. They cool the river water before it gets put back into the river, so you don't kill the fish.
    Let's see your thermodynamic calculations to prove your statement about the reduced efficiency.
    Steam loses pressure as it passes throug the turbine, because condensed steam takes up less volume. It is the difference in pressure that makes the steam pass through the turbine. No pressure drop = no power generated.

    How clean does it have to be? Well consider that when you boil water, any minerals and dirt in the water are left behind. Your boiler would fill up with dirt in minutes. If you ever get a chance, take a look inside the basin of one of those cooling towers. It's probably full of mud.
    As for the pressure change of the steam having passed through the turbines because of the volume differential, this was not what Bunbury was saying.

    He was saying that the steam loses pressure having given up most of its energy to the turbines.

    However you would not get a pressure drop after the steam left the turbines if it were blocked by a condenser.

    And how do you separate the steam from the condensed water?

    They cool the river water before it gets put back into the river, so you don't kill the fish.
    So you admit that Nuclear power stations can use river water as well as seawater?

    Well if those are cooling towers on the blow in that image of the nuclear power plant in Germany then they are certainly wasting a hell of a lot of energy.

    Reply With Quote  
     

  25. #24  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by galexander
    As for the pressure change of the steam having passed through the turbines because of the volume differential, this was not what Bunbury was saying.

    He was saying that the steam loses pressure having given up most of its energy to the turbines.
    There are a lot of different ways to say the same thing. Since you do not believe in kinetic energy, I thought you would like that explanation better.
    However you would not get a pressure drop after the steam left the turbines if it were blocked by a condenser.

    And how do you separate the steam from the condensed water?
    You pump the water out from the bottom of the condensate storage tank. Voila, it's separated.
    They cool the river water before it gets put back into the river, so you don't kill the fish.
    So you admit that Nuclear power stations can use river water as well as seawater?
    I not only admit it, I absolutely certify and guarantee it.
    Well if those are cooling towers on the blow in that image of the nuclear power plant in Germany then they are certainly wasting a hell of a lot of energy.

    Yeah, well nobody ever said the Rankine cycle is 100% efficient.
    Reply With Quote  
     

  26. #25  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Harold14370
    Quote Originally Posted by galexander
    As for the pressure change of the steam having passed through the turbines because of the volume differential, this was not what Bunbury was saying.

    He was saying that the steam loses pressure having given up most of its energy to the turbines.
    There are a lot of different ways to say the same thing. Since you do not believe in kinetic energy, I thought you would like that explanation better.
    However you would not get a pressure drop after the steam left the turbines if it were blocked by a condenser.

    And how do you separate the steam from the condensed water?
    You pump the water out from the bottom of the condensate storage tank. Voila, it's separated.
    They cool the river water before it gets put back into the river, so you don't kill the fish.
    So you admit that Nuclear power stations can use river water as well as seawater?
    I not only admit it, I absolutely certify and guarantee it.
    Well if those are cooling towers on the blow in that image of the nuclear power plant in Germany then they are certainly wasting a hell of a lot of energy.

    Yeah, well nobody ever said the Rankine cycle is 100% efficient.
    Yeah, and even less efficient when you consider that the 'steam engine' has also been baffled by condensers which are impeding the flow of steam.

    Rather like the baffles on a low cc motorbike to reduce the speed........... :wink:
    Reply With Quote  
     

  27. #26  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Yeah, and even less efficient when you consider that the 'steam engine' has also been baffled by condensers which are impeding the flow of steam.
    If you would bother to read up on the Rankine cycle you might begin to understand some of this. The condenser uses cooling water from a river or a sea, or in dry areas it can use air as the coolant. The purpose of the coolant is to remove latent heat from the steam and condense it to water. The lower the temperature at which it can be condensed, the more efficient the cycle becomes.

    Condensers do not impede the flow of steam. In fact it's the very opposite. As already mentioned, if you let the steam exhaust from the turbines to the atmosphere it vents at atmospheric pressure and around 100 degrees C. By condensing it in a condenser using a coolant that is well below 100 degrees C (air or water) the condensing pressure is reduced to a fraction of a bar. This increases the pressure drop from the intake to the exhaust of the turbine, increasing its efficiency.

    As Harold has already explained to you, the cooling towers cool river water by evaporating a fraction of the water. What you see is not steam, it is condensed water vapor that condenses when the warm saturated air leaving the tower contacts cold ambient air. And yes, it represents just one of many inefficiencies, which add up to explain why the thermal efficiency of fossil electric generating plants is typically less than 50%, and nuclear is somewhat less efficient.
    Reply With Quote  
     

  28. #27  
    Forum Professor Wild Cobra's Avatar
    Join Date
    Sep 2009
    Posts
    1,140
    Quote Originally Posted by Harold14370
    Everyone seems to be focusing on the nuclear plants, which haven't killed anybody yet, as far as I know. Meanwhile the tragedy of people over there freezing in the cold without any food is being largely ignored.
    No kidding.

    Besides, more people die from windmills.
    Reply With Quote  
     

  29. #28  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    Yeah, and even less efficient when you consider that the 'steam engine' has also been baffled by condensers which are impeding the flow of steam.
    If you would bother to read up on the Rankine cycle you might begin to understand some of this. The condenser uses cooling water from a river or a sea, or in dry areas it can use air as the coolant. The purpose of the coolant is to remove latent heat from the steam and condense it to water. The lower the temperature at which it can be condensed, the more efficient the cycle becomes.

    Condensers do not impede the flow of steam. In fact it's the very opposite. As already mentioned, if you let the steam exhaust from the turbines to the atmosphere it vents at atmospheric pressure and around 100 degrees C. By condensing it in a condenser using a coolant that is well below 100 degrees C (air or water) the condensing pressure is reduced to a fraction of a bar. This increases the pressure drop from the intake to the exhaust of the turbine, increasing its efficiency.

    As Harold has already explained to you, the cooling towers cool river water by evaporating a fraction of the water. What you see is not steam, it is condensed water vapor that condenses when the warm saturated air leaving the tower contacts cold ambient air. And yes, it represents just one of many inefficiencies, which add up to explain why the thermal efficiency of fossil electric generating plants is typically less than 50%, and nuclear is somewhat less efficient.
    Well we have turned a full circle and come back to the original point:

    Why was the Fukushima nuclear plant built so close to the sea?

    Bunbury informs us of the following:

    The condenser uses cooling water from a river or a sea, or in dry areas it can use air as the coolant.
    So why not build the plant at Fukushima by a river instead or just use cool air?

    As for the supposed efficiency of the Rankin cycle that efficiency would be severely reduced by the velocity of the steam and the surface area of the condenser available. I mean how could you guarantee that all the steam would be captured by the available surface area of the condenser without severely restricting the motion of the steam and hence turning power?
    Reply With Quote  
     

  30. #29  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by galexander
    Well we have turned a full circle and come back to the original point:

    Why was the Fukushima nuclear plant built so close to the sea?

    Bunbury informs us of the following:

    The condenser uses cooling water from a river or a sea, or in dry areas it can use air as the coolant.
    So why not build the plant at Fukushima by a river instead or just use cool air?
    Japan is a group of islands. There may not be any suitable sites on a river or lake. I don't know of any air cooled power plants. It's probably not feasible for something that large.

    In hindsight, they didn't design for a big enough tsunami. That's obvious now. Congratulations on your observation.
    Reply With Quote  
     

  31. #30  
    Veracity Vigilante inow's Avatar
    Join Date
    Oct 2009
    Location
    Austin, TX
    Posts
    3,500
    Quote Originally Posted by Wild Cobra
    Besides, more people die from windmills.
    I wonder how willing you'd be to revisit this assertion in a few months, or a few years as we learn more about the health effects of what's happening right now in Japan.

    I love how deniers and the "drill baby drill" crowd has all glommed on to this one story about how nuclear has been relatively safe, but that a few people have died recently while installing or being too near to wind power... and how this ideological crowd has each reproduced this "wind is less safe than nuclear" comment in their bobble head echo chamber throughout the internet to suggest we're wasting our time with wind, or there is only one correct power source option...

    I could quite easily challenge the method they used to calculate deaths from nuclear given the fact that they ignored radiation sickness among workers at nuclear sites, but I'll take another route.

    Yes, wind power is in its infancy and we're still learning. Some safety measures with some things are not yet well developed, and people have died or been hurt. People fall of the tops of these things, sky divers haven't yet learned not to jump out of planes above them, and ice flying off them is an issue. Procedures will change as a result. Things could have been different, but technologies in their infancy often require mistakes before corrections can be made.

    A more accurate comparison would not be wind to today's nuclear, but with wind to nuclear in it's first one or two decades. Let's look at the death numbers when we first began with nuclear in the 1950s and 60s and use that as a more valid point of comparison, shall we?


    Let me ask you a more on topic question, though. Do you think if Japan were fully powered by wind we'd be as anxious about Japan right now post-earthquake and post-tsunami? Do you think if they were all using wind power instead of nuclear we'd be evacuating people en masse and having people die from exposure?

    I'm actually a proponent of nuclear, and I have enjoyed finding alignment with Harold on these recent threads, so you don't get to accurately fry me over that. I think nuclear is a critical component of our energy needs (no pun intended). I'm just saying, when you make comments like you did here it does little more than show your extreme bias and desire to skew peoples reactions.



    EDIT: Funny how you didn't mention coal, oil, or gas when making your comment about the death rate from wind.

    http://nextbigfuture.com/2011/03/dea...gy-source.html

    Energy Source.....................................Death Rate (deaths per TWh)

    Coal – world average.............................161 (26% of world energy, 50% of electricity)
    Coal – China..........................................278
    Coal – USA.............................................15
    Oil............................................... ...........36 (36% of world energy)
    Natural Gas..............................................4 (21% of world energy)
    Biofuel/Biomass.......................................12
    Peat.............................................. ..........12
    Solar (rooftop)......................................... ..0.44 (less than 0.1% of world energy)
    Wind.............................................. ...........0.15 (less than 1% of world energy)
    Hydro............................................. ..........0.10 (europe death rate, 2.2% of world energy)
    Hydro - world including Banqiao)...............1.4 (about 2500 TWh/yr and 171,000 Banqiao dead)
    Nuclear........................................... .........0.04 (5.9% of world energy)






    Non-roof installations of solar is safer than roof installation. Nuclear, wind, non-roof solar and hydro are a lot safer than coal and oil. Natural gas is safer but not as much as nuclear and those others. The focus needs to be on getting rid of the most dangerous energy sources which are coal and oil first. Then after that decades long project is done to look at the other energy sources. Safety and improvements for all energy sources should be made as we go.
    Reply With Quote  
     

  32. #31  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Harold14370
    Quote Originally Posted by galexander
    Well we have turned a full circle and come back to the original point:

    Why was the Fukushima nuclear plant built so close to the sea?

    Bunbury informs us of the following:

    The condenser uses cooling water from a river or a sea, or in dry areas it can use air as the coolant.
    So why not build the plant at Fukushima by a river instead or just use cool air?
    Japan is a group of islands. There may not be any suitable sites on a river or lake. I don't know of any air cooled power plants. It's probably not feasible for something that large.

    In hindsight, they didn't design for a big enough tsunami. That's obvious now. Congratulations on your observation.
    So Harold14370, Japan is just a group of islands and it "may" not have any rivers or lakes.

    Are you serious?!

    Japan is bigger than the United Kingdom and yes it does have plenty of rivers and lakes. The largest lake in Japan is far larger than any lake found in the UK.

    Classic..........! :-D
    Reply With Quote  
     

  33. #32  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Quote Originally Posted by Harold14370
    I don't know of any air cooled power plants. It's probably not feasible for something that large.
    It is feasible. The efficiency tends to be lower because air in summer time is often warmer than most bodies of water, and the fans consume a lot of power. In wintertime you have to apply freeze-prevention measures that add to operating costs. The air cooled condensers are also very large and expensive so if water is available it is used instead of air. Here are some references.

    http://spxcooling.com/pdf/Dry-Ref-Glo-09A.pdf

    There is apparently only one air-cooled nuclear power station (in Russia) but EPRI is considering air cooling for future nukes.

    http://mydocs.epri.com/docs/Advanced...sk_Nuclear.pdf
    Reply With Quote  
     

  34. #33  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Quote Originally Posted by galexander
    As for the supposed efficiency of the Rankin cycle that efficiency would be severely reduced by the velocity of the steam and the surface area of the condenser available. I mean how could you guarantee that all the steam would be captured by the available surface area of the condenser without severely restricting the motion of the steam and hence turning power?
    Design of steam condensers for power plants is a well-developed and proven technology. The geometry of tube bundles has evolved to the point where the condensers are highly optimized for the job. Your assertions do not change this. The efficiency of the Rankine cycle is not supposed, it is carefully calculated.
    Reply With Quote  
     

  35. #34  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    Quote Originally Posted by galexander
    As for the supposed efficiency of the Rankin cycle that efficiency would be severely reduced by the velocity of the steam and the surface area of the condenser available. I mean how could you guarantee that all the steam would be captured by the available surface area of the condenser without severely restricting the motion of the steam and hence turning power?
    Design of steam condensers for power plants is a well-developed and proven technology. The geometry of tube bundles has evolved to the point where the condensers are highly optimized for the job. Your assertions do not change this. The efficiency of the Rankine cycle is not supposed, it is carefully calculated.
    Okay so do all power stations which use the Rankin cycle such as gas and coal fired stations also require tonnes of seawater?
    Reply With Quote  
     

  36. #35  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Quote Originally Posted by galexander
    Okay so do all power stations which use the Rankin cycle such as gas and coal fired stations also require tonnes of seawater?
    It's Rankine not Rankin. Your question has already been answered in this thread.
    Reply With Quote  
     

  37. #36  
    Forum Junior
    Join Date
    Feb 2008
    Posts
    286
    they built it near the sea because theyre stupid i think

    did the water from tsunami reach it?

    people use this form of power because they are stupid i think
    Reply With Quote  
     

  38. #37  
    Forum Ph.D.
    Join Date
    Dec 2006
    Posts
    899
    Quote Originally Posted by Holmes
    they built it near the sea because theyre stupid i think

    did the water from tsunami reach it?

    people use this form of power because they are stupid i think
    I rarely (if ever) understand these highly technical posts!
    Reply With Quote  
     

  39. #38  
    Comet Dust Collector Moderator
    Join Date
    Mar 2011
    Location
    New Jersey, USA
    Posts
    2,848
    That's not surpising considering the strongly constructed, logical argument!
    Reply With Quote  
     

  40. #39  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    Quote Originally Posted by galexander
    Okay so do all power stations which use the Rankin cycle such as gas and coal fired stations also require tonnes of seawater?
    It's Rankine not Rankin. Your question has already been answered in this thread.
    Okay, I have been complaining about the Rankine cycle and probably haven't been making a lot of sense.

    I am now going to lay my cards on the table.

    When water is converted to steam its volume increases 10,500 fold from liquid to gas.

    Therefore to convert the equivalent amount of steam back to water at one end of the Rankine cycle as is turned into steam at the other, the amount of surface area available in the condenser would have to be 10,500 fold greater than the heating element.

    This is some ratio I think you can admit.

    Further Wiki has this to say on the Rankine cycle:

    The Rankine cycle is sometimes referred to as a practical Carnot cycle because, when an efficient turbine is used, the TS diagram begins to resemble the Carnot cycle.
    So the Rankine cycle is a practical form of the theoretical Carnot cycle. But Wiki also has this to say on the Carnot heat engine which operates on the principle of the Carnot cycle:

    A Carnot heat engine[2] is a hypothetical engine that operates on the reversible Carnot cycle.
    Further, to underline the point the HarperCollins book of Physcis, 2002, Second Edition has this to say on the Carnot heat engine on page 324:

    A Carnot engine cannot actually exist - it is just an imaginary ideal engine in which there is are no energy losses, such as through friction and conduction.
    Reply With Quote  
     

  41. #40  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Quote Originally Posted by galexander
    I am now going to lay my cards on the table.

    When water is converted to steam its volume increases 10,500 fold from liquid to gas.
    That is correct only if you are boiling water under high vacuum. Power boilers do not operate under vacuum.

    Therefore to convert the equivalent amount of steam back to water at one end of the Rankine cycle as is turned into steam at the other, the amount of surface area available in the condenser would have to be 10,500 fold greater than the heating element.

    This is some ratio I think you can admit.
    That ratio is approximately the ratio of the density of water to the density of steam in a condenser. Surface area depends on many factors and this ratio is not one of them, at least not directly.

    Further Wiki has this to say on the Rankine cycle:

    The Rankine cycle is sometimes referred to as a practical Carnot cycle because, when an efficient turbine is used, the TS diagram begins to resemble the Carnot cycle.
    So the Rankine cycle is a practical form of the theoretical Carnot cycle. But Wiki also has this to say on the Carnot heat engine which operates on the principle of the Carnot cycle:

    A Carnot heat engine[2] is a hypothetical engine that operates on the reversible Carnot cycle.
    Further, to underline the point the HarperCollins book of Physcis, 2002, Second Edition has this to say on the Carnot heat engine on page 324:

    A Carnot engine cannot actually exist - it is just an imaginary ideal engine in which there is are no energy losses, such as through friction and conduction.
    So? What's your point?
    Reply With Quote  
     

  42. #41  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    Quote Originally Posted by galexander
    I am now going to lay my cards on the table.

    When water is converted to steam its volume increases 10,500 fold from liquid to gas.
    That is correct only if you are boiling water under high vacuum. Power boilers do not operate under vacuum.

    Therefore to convert the equivalent amount of steam back to water at one end of the Rankine cycle as is turned into steam at the other, the amount of surface area available in the condenser would have to be 10,500 fold greater than the heating element.

    This is some ratio I think you can admit.
    That ratio is approximately the ratio of the density of water to the density of steam in a condenser. Surface area depends on many factors and this ratio is not one of them, at least not directly.

    Further Wiki has this to say on the Rankine cycle:

    The Rankine cycle is sometimes referred to as a practical Carnot cycle because, when an efficient turbine is used, the TS diagram begins to resemble the Carnot cycle.
    So the Rankine cycle is a practical form of the theoretical Carnot cycle. But Wiki also has this to say on the Carnot heat engine which operates on the principle of the Carnot cycle:

    A Carnot heat engine[2] is a hypothetical engine that operates on the reversible Carnot cycle.
    Further, to underline the point the HarperCollins book of Physcis, 2002, Second Edition has this to say on the Carnot heat engine on page 324:

    A Carnot engine cannot actually exist - it is just an imaginary ideal engine in which there is are no energy losses, such as through friction and conduction.
    So? What's your point?
    I suggest you re-read what I said more carefully.

    It was quite obvious what I was saying and I am not going to repeat it.
    Reply With Quote  
     

  43. #42  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    OK by me.
    Reply With Quote  
     

  44. #43  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    Quote Originally Posted by galexander
    I am now going to lay my cards on the table.

    When water is converted to steam its volume increases 10,500 fold from liquid to gas.
    That is correct only if you are boiling water under high vacuum. Power boilers do not operate under vacuum.
    Steam produced into a vacuum will produce an infinite volume (assuming the container is also infinite).
    Reply With Quote  
     

  45. #44  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    The following is the page in Wiki on the steam engine:

    http://en.wikipedia.org/wiki/Steam_engine

    On that page it says the following with regard to the Rankine cycle:

    Steam engines are typically external combustion engines,[1] E.C.E.[›] although other external sources of heat such as solar power, nuclear power or geothermal energy may be used. The heat cycle is known as the Rankine cycle.
    Please tell me where the condenser is on the following steam engine from the same page?

    Reply With Quote  
     

  46. #45  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    You possibly didn’t understand the term “high vacuum”. It is not the same as “full vacuum”.

    The function of a condenser is to improve the efficiency where fuel costs are an important factor, and to reduce the water consumption. If these factors are unimportant you don’t have to condense the steam. What is the efficiency of the red steam engine? What was the price of coal in those days? How many buckets of water were needed to go a mile? What is the operating pressure of the boiler? As already stated:

    If you did not condense the steam you would have to vent it to atmosphere and then you would have two problems:
    a) You would need a source of huge amounts of very clean water. This is completely impractical.
    b) You would have to vent the steam at atmospheric pressure, instead of at a few inches of mercury vacuum, which greatly reduces the efficiency of the turbines.

    We were discussing power plants not traction engines. Your somewhat belligerent tone is not conducive to reasonable discussion. I don’t understand why my every attempt at providing a clear and reasonable response to your questions is treated by you as a personal affront. You are rude and have an enormous chip on your shoulder for some reason I can’t fathom. I don’t care to continue in this mode of debate.
    Reply With Quote  
     

  47. #46  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,169
    Quote Originally Posted by galexander
    It was quite obvious what I was saying and I am not going to repeat it.
    Off topic observation and question. Conventional thinking among thoughtful people recognises that the primary responsibility for communicating a clear message lies with the speaker or writer, not with the listener or reader. If a reader decalres they have not understood the point of a communication it is accepted that the writer should make a further, more careful attempt to make their point. Do you disagree with this approach and if so on what basis?
    Reply With Quote  
     

  48. #47  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by galexander
    It was quite obvious what I was saying and I am not going to repeat it.
    Off topic observation and question. Conventional thinking among thoughtful people recognises that the primary responsibility for communicating a clear message lies with the speaker or writer, not with the listener or reader. If a reader decalres they have not understood the point of a communication it is accepted that the writer should make a further, more careful attempt to make their point. Do you disagree with this approach and if so on what basis?
    But what if the fellow debater chooses to ignore the point raised claiming he can't understand it?

    Are you agreeing with Bunbury?

    If you are please say so.
    Reply With Quote  
     

  49. #48  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    You possibly didn’t understand the term “high vacuum”. It is not the same as “full vacuum”.

    The function of a condenser is to improve the efficiency where fuel costs are an important factor, and to reduce the water consumption. If these factors are unimportant you don’t have to condense the steam. What is the efficiency of the red steam engine? What was the price of coal in those days? How many buckets of water were needed to go a mile? What is the operating pressure of the boiler? As already stated:

    If you did not condense the steam you would have to vent it to atmosphere and then you would have two problems:
    a) You would need a source of huge amounts of very clean water. This is completely impractical.
    b) You would have to vent the steam at atmospheric pressure, instead of at a few inches of mercury vacuum, which greatly reduces the efficiency of the turbines.

    We were discussing power plants not traction engines. Your somewhat belligerent tone is not conducive to reasonable discussion. I don’t understand why my every attempt at providing a clear and reasonable response to your questions is treated by you as a personal affront. You are rude and have an enormous chip on your shoulder for some reason I can’t fathom. I don’t care to continue in this mode of debate.
    The simple point I was making and which you have clearly ignored, is that the traction engine I had pictured is also claimed to run on the Rankine cycle.

    How do you explain this simple observation?

    And further I deny being rude. You are going on the defensive.
    Reply With Quote  
     

  50. #49  
    Forum Freshman
    Join Date
    Jul 2010
    Posts
    97
    Quote Originally Posted by galexander
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by galexander
    It was quite obvious what I was saying and I am not going to repeat it.
    Off topic observation and question. Conventional thinking among thoughtful people recognises that the primary responsibility for communicating a clear message lies with the speaker or writer, not with the listener or reader. If a reader decalres they have not understood the point of a communication it is accepted that the writer should make a further, more careful attempt to make their point. Do you disagree with this approach and if so on what basis?
    But what if the fellow debater chooses to ignore the point raised claiming he can't understand it?

    Are you agreeing with Bunbury?

    If you are please say so.
    Well, I am not sure I got your point either.

    As I got it you stated that the Rankine cycle resembles the carnot cycle. But that it can not be a perfect carnor cycle as that is impossible.

    Which sure is a statement, but I can not see what question it raises or which points that should not be ignored in this debate.

    Was it something more to it?
    "Complexity is stupidity disguised as intellect."
    Reply With Quote  
     

  51. #50  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Quote Originally Posted by galexander
    How do you explain this simple observation?

    And further I deny being rude.
    I find this juxtaposition ironic.
    Reply With Quote  
     

  52. #51  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by jakotaco
    Quote Originally Posted by galexander
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by galexander
    It was quite obvious what I was saying and I am not going to repeat it.
    Off topic observation and question. Conventional thinking among thoughtful people recognises that the primary responsibility for communicating a clear message lies with the speaker or writer, not with the listener or reader. If a reader decalres they have not understood the point of a communication it is accepted that the writer should make a further, more careful attempt to make their point. Do you disagree with this approach and if so on what basis?
    But what if the fellow debater chooses to ignore the point raised claiming he can't understand it?

    Are you agreeing with Bunbury?

    If you are please say so.
    Well, I am not sure I got your point either.

    As I got it you stated that the Rankine cycle resembles the carnot cycle. But that it can not be a perfect carnor cycle as that is impossible.

    Which sure is a statement, but I can not see what question it raises or which points that should not be ignored in this debate.

    Was it something more to it?
    The points that cropped up are as follows:

    It is not just nuclear power that uses the Rankine cycle.

    Gas and coal fired power stations should also therefore need heaps upon heaps of seawater.

    Since a chain is only as strong as its weakest link, what is actually driving the turbines in the Rankine cycle is suction from the condenser. The heat source supplying the steam is of secondary interest therefore. This surely has to reflect upon both the efficiency and the safety of nuclear energy.
    Reply With Quote  
     

  53. #52  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by galexander
    The points that cropped up are as follows:

    It is not just nuclear power that uses the Rankine cycle.

    Gas and coal fired power stations should also therefore need heaps upon heaps of seawater.

    Since a chain is only as strong as its weakest link, what is actually driving the turbines in the Rankine cycle is suction from the condenser. The heat source supplying the steam is of secondary interest therefore. This surely has to reflect upon both the efficiency and the safety of nuclear energy.
    Fossil plants do indeed use heaps of cooling water. If you care to look into the matter, you will find they also need cooling towers for large plants sited on lakes or rivers.
    http://en.wikipedia.org/wiki/Didcot_Power_Station

    The heat source has a lot to do with it, not just the condenser. The hotter the source, the more efficient. Fossil plants can get the steam a bit hotter than nuclear plants, so they are more efficient, but not dramatically so.

    How do you think the efficiency impacts safety?
    Reply With Quote  
     

  54. #53  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Even plants using unconventional heat sources, such as CSP, still use the Rankine cycle and still require cooling. Since CSP plants are likely to located in water-poor areas they will be more likely to use air cooling instead of water cooling.
    Reply With Quote  
     

  55. #54  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,169
    Quote Originally Posted by galexander
    Gas and coal fired power stations should also therefore need heaps upon heaps of seawater.
    Heaps of water, not necessarily sea water. Sea water is a bad idea because it is corrosive. You made this statement as though you were challenging the idea that fossil fuel stations needed cooling. If that was not your intent what was the point of your statement? If that was your intent, why are you even arguing here when your ignorance is clearly profound? If you are not arguing, but trying to improve your understanding, may I suggest you moderate the attitude.
    Reply With Quote  
     

  56. #55  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Harold14370
    Quote Originally Posted by galexander
    The points that cropped up are as follows:

    It is not just nuclear power that uses the Rankine cycle.

    Gas and coal fired power stations should also therefore need heaps upon heaps of seawater.

    Since a chain is only as strong as its weakest link, what is actually driving the turbines in the Rankine cycle is suction from the condenser. The heat source supplying the steam is of secondary interest therefore. This surely has to reflect upon both the efficiency and the safety of nuclear energy.
    Fossil plants do indeed use heaps of cooling water. If you care to look into the matter, you will find they also need cooling towers for large plants sited on lakes or rivers.
    http://en.wikipedia.org/wiki/Didcot_Power_Station

    The heat source has a lot to do with it, not just the condenser. The hotter the source, the more efficient. Fossil plants can get the steam a bit hotter than nuclear plants, so they are more efficient, but not dramatically so.

    How do you think the efficiency impacts safety?
    Well I used to live not that far away from Didcot power station and I don't recall it being near any rivers or lakes of any significant size.
    Reply With Quote  
     

  57. #56  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by galexander
    Gas and coal fired power stations should also therefore need heaps upon heaps of seawater.
    Heaps of water, not necessarily sea water. Sea water is a bad idea because it is corrosive. You made this statement as though you were challenging the idea that fossil fuel stations needed cooling. If that was not your intent what was the point of your statement? If that was your intent, why are you even arguing here when your ignorance is clearly profound? If you are not arguing, but trying to improve your understanding, may I suggest you moderate the attitude.
    Fine, but look again more closely at the point of view I was replying to:


    Lynx_Fox wrote:
    There are some advantages to keeping it close to the sea as well including flat terrain to build on, available water for cooling or heat exchange, and in a worse case scenario most radioactive particles would go with the prevailing Westerlies out to sea.
    What with radioactive particles being washed out to sea I had visions of the seawater being used to cool the reactor core................!
    Reply With Quote  
     

  58. #57  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Quote Originally Posted by galexander
    Well I used to live not that far away from Didcot power station and I don't recall it being near any rivers or lakes of any significant size.
    Didcot A consists of four 500 MW units. Inlet steam is at 568°C/165bar and the reheat is 568°C/39 bar. Condenser pressure is about 0.5 psi ( 0.035 bar/ 40°C). The station uses the usual hyperbolic cooling towers, using water drawn from the Thames. The water loss is 32000 gallons per day (145 cu m) and a similar amount of slightly warm water is returned to the Thames. There are four cooling towers on the plant itself plus two others about half a mile away.
    From a map, the power station seems to be about 2 miles from the Thames. Presumably they built a pipeline or a canal.

    http://www.claverton-energy.com/didc...-stations.html

    Google is a powerful tool.
    Reply With Quote  
     

  59. #58  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by galexander
    Well I used to live not that far away from Didcot power station and I don't recall it being near any rivers or lakes of any significant size.
    http://news.bbc.co.uk/2/hi/business/7771874.stm
    The water used by Npower, explains Mr Waygood, comes from the same source that everyone else uses locally: the river Thames.
    Reply With Quote  
     

  60. #59  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    Quote Originally Posted by galexander
    Well I used to live not that far away from Didcot power station and I don't recall it being near any rivers or lakes of any significant size.
    Didcot A consists of four 500 MW units. Inlet steam is at 568°C/165bar and the reheat is 568°C/39 bar. Condenser pressure is about 0.5 psi ( 0.035 bar/ 40°C). The station uses the usual hyperbolic cooling towers, using water drawn from the Thames. The water loss is 32000 gallons per day (145 cu m) and a similar amount of slightly warm water is returned to the Thames. There are four cooling towers on the plant itself plus two others about half a mile away.
    From a map, the power station seems to be about 2 miles from the Thames. Presumably they built a pipeline or a canal.

    http://www.claverton-energy.com/didc...-stations.html

    Google is a powerful tool.
    How do you explain the 32000 gallons of water loss per day?

    If this goes up the cooling towers it is a fantastic waste of energy. Why don't they simply burn less coal?

    And what is the point of pumping 32,000 gallons of water to the station only to return the same amount of 'slightly warm water' back to the source each and every day? Why not just keep the water to save all that pumping?
    Reply With Quote  
     

  61. #60  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by galexander
    Quote Originally Posted by Bunbury
    Quote Originally Posted by galexander
    Well I used to live not that far away from Didcot power station and I don't recall it being near any rivers or lakes of any significant size.
    Didcot A consists of four 500 MW units. Inlet steam is at 568°C/165bar and the reheat is 568°C/39 bar. Condenser pressure is about 0.5 psi ( 0.035 bar/ 40°C). The station uses the usual hyperbolic cooling towers, using water drawn from the Thames. The water loss is 32000 gallons per day (145 cu m) and a similar amount of slightly warm water is returned to the Thames. There are four cooling towers on the plant itself plus two others about half a mile away.
    From a map, the power station seems to be about 2 miles from the Thames. Presumably they built a pipeline or a canal.

    http://www.claverton-energy.com/didc...-stations.html

    Google is a powerful tool.
    How do you explain the 32000 gallons of water loss per day?

    If this goes up the cooling towers it is a fantastic waste of energy. Why don't they simply burn less coal?

    And what is the point of pumping 32,000 gallons of water to the station only to return the same amount of 'slightly warm water' back to the source each and every day? Why not just keep the water to save all that pumping?
    What these statistics are saying is that the Coal fired power station in using just as much water to stay cool or is wasted heat as is used to power the Rankine cycle and cool the condensers.

    The maths does NOT add up..........!
    Reply With Quote  
     

  62. #61  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Quote Originally Posted by galexander
    How do you explain the 32000 gallons of water loss per day?

    If this goes up the cooling towers it is a fantastic waste of energy. Why don't they simply burn less coal?

    And what is the point of pumping 32,000 gallons of water to the station only to return the same amount of 'slightly warm water' back to the source each and every day? Why not just keep the water to save all that pumping?
    I thought you understood that the Rankine cycle was not 100 percent efficient. If it is not 100% efficient, there will be waste heat. If you did not pump the water, you would have no way to cool the condenser. What that article actually said that 32,000 gallons of water is lost by evaporation in the cooling tower, and a similar amount of slightly warm water is returned to the river. That is a total of about 64,000 gallons per day pumped. If you returned all the water to the river, it would be quite hot, and would kill fish.
    What these statistics are saying is that the Coal fired power station in using just as much water to stay cool or is wasted heat as is used to power the Rankine cycle and cool the condensers.

    The maths does NOT add up..........!
    This assumes you have actually learned the physics and done the math, which you clearly haven't.
    Reply With Quote  
     

  63. #62  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Harold14370
    Quote Originally Posted by galexander
    How do you explain the 32000 gallons of water loss per day?

    If this goes up the cooling towers it is a fantastic waste of energy. Why don't they simply burn less coal?

    And what is the point of pumping 32,000 gallons of water to the station only to return the same amount of 'slightly warm water' back to the source each and every day? Why not just keep the water to save all that pumping?
    I thought you understood that the Rankine cycle was not 100 percent efficient. If it is not 100% efficient, there will be waste heat. If you did not pump the water, you would have no way to cool the condenser. What that article actually said that 32,000 gallons of water is lost by evaporation in the cooling tower, and a similar amount of slightly warm water is returned to the river. That is a total of about 64,000 gallons per day pumped. If you returned all the water to the river, it would be quite hot, and would kill fish.
    What these statistics are saying is that the Coal fired power station in using just as much water to stay cool or is wasted heat as is used to power the Rankine cycle and cool the condensers.

    The maths does NOT add up..........!
    This assumes you have actually learned the physics and done the math, which you clearly haven't.
    I'm going to call you on this one Harold14370.

    If 32,000 gallons of water goes up the cooling towers as steam (i.e. is converted from water to hot steam) and 32,000 gallons of cool water is converted to slightly warm water, then that to me strongly suggests a NEGATIVE efficiency.

    What I mean by this is that more energy is being lost in running the plant than is being converted into usable electricity.

    For a start a huge amount of 'cold' water should be being used to cool the condensers and yet the suggestion is that an equal volume is being converted to steam in the cooling towers.

    Let me point it takes MORE energy to convert water to steam in the cooling towers than it does to heat cool water to slightly warm water.

    Most of the heat generated by the coal fires must THEREFORE be going up the chimneys.

    Only SOME of the heat is being lost to the river water.
    Reply With Quote  
     

  64. #63  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    What I mean by this is that more energy is being lost in running the plant than is being converted into usable electricity.
    Congratulations, you finally understand something. This what less than 50% efficient means.
    Reply With Quote  
     

  65. #64  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    What I mean by this is that more energy is being lost in running the plant than is being converted into usable electricity.
    Congratulations, you finally understand something. This what less than 50% efficient means.
    Ah yes......but HOW MUCH less than 50% are we talking about?

    32,000 gallons per day of cool water to boiling equals say, at least a 100C temp change of completely wasted energy in the cooling towers.

    32,000 gallons per day to cool the steam produced by the coal fire in the condenser, say a 20C temp change.

    Therefore at least 5 times as much energy is wasted in the cooling towers as is used cooling the steam produced by the coal fires and condensing it back to water again.

    This means that only 1/6 of the heat energy is actually used to drive the generators.

    But there are even more factors to take into account when calculating the overall efficiency.

    Think of the energy used to pump the 32,000 x 3 = 96,000 gallons of water per day to and from the Thames.

    And there are other losses too.

    The efficiency is so low it may even be negative.........that is more energy is used to run the station than is generated by it!! :?
    Reply With Quote  
     

  66. #65  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    You know what, you can find ALL of this stuff by using Google.

    Typical thermal efficiency for electrical generators in the industry is around 33% for coal and oil-fired plants, and up to 50% for combined-cycle gas-fired plants.
    And this is wrong:

    32,000 gallons per day of cool water to boiling equals say, at least a 100C temp change of completely wasted energy in the cooling towers.
    Nothing is boiling in the cooling towers. It is evaporation into the air stream; you know, like when you hang your undies out on the clothesline they get dry without any boiling occurring. Any time the air is unsaturated with water vapor there will be a mass transfer of water into the air, and a resultant transfer of latent heat from the water to the air which is what causes the water to become cooler. The actual temperature is nowhere near 100C.
    Reply With Quote  
     

  67. #66  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    You know what, you can find ALL of this stuff by using Google.

    Typical thermal efficiency for electrical generators in the industry is around 33% for coal and oil-fired plants, and up to 50% for combined-cycle gas-fired plants.
    And this is wrong:

    32,000 gallons per day of cool water to boiling equals say, at least a 100C temp change of completely wasted energy in the cooling towers.
    Nothing is boiling in the cooling towers. It is evaporation into the air stream; you know, like when you hang your undies out on the clothesline they get dry without any boiling occurring. Any time the air is unsaturated with water vapor there will be a mass transfer of water into the air, and a resultant transfer of latent heat from the water to the air which is what causes the water to become cooler. The actual temperature is nowhere near 100C.



    For this much 'steam' to form above these cooling towers I think a little more than simple evaporation is involved.

    Look at the altitude of the clouds above the plant.

    And how quickly can water evaporate on what is probably NOT a scorching hot day with extremely high humidity?

    And yet you claim simple evaporation is involved.
    Reply With Quote  
     

  68. #67  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    I'm very sorry you do not understand the physics, but as the saying goes, you can lead a horse to water but you can't make it drink. I strongly suggest you go away and read and think, and come back when there is a glimmering of comprehension in your brain. Otherwise this a just futile.
    Reply With Quote  
     

  69. #68  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    [quote="galexander"]
    Quote Originally Posted by Bunbury
    You know what, you can find ALL of this stuff by using Google.

    Typical thermal efficiency for electrical generators in the industry is around 33% for coal and oil-fired plants, and up to 50% for combined-cycle gas-fired plants.
    And this is wrong:

    32,000 gallons per day of cool water to boiling equals say, at least a 100C temp change of completely wasted energy in the cooling towers.
    Nothing is boiling in the cooling towers. It is evaporation into the air stream; you know, like when you hang your undies out on the clothesline they get dry without any boiling occurring. Any time the air is unsaturated with water vapor there will be a mass transfer of water into the air, and a resultant transfer of latent heat from the water to the air which is what causes the water to become cooler. The actual temperature is nowhere near 100C.



    For this much 'steam' to form above these cooling towers I think a little more than simple evaporation is involved.

    Look at the altitude of the clouds above the plant.

    And how quickly can water evaporate on what is probably NOT a scorching hot day with extremely high humidity?

    Also notice the leaves on the trees indicating it is summer.

    And yet you claim simple evaporation is involved.
    Reply With Quote  
     

  70. #69  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    I'm very sorry you do not understand the physics, but as the saying goes, you can lead a horse to water but you can't make it drink. I strongly suggest you go away and read and think, and come back when there is a glimmering of comprehension in your brain. Otherwise this a just futile.
    I put this question to you Bunbury.

    Have you ever seen clouds of steam rising from a lake as it is heated in the Sun's rays?

    I have not.

    Okay you will get some steam rising from an outdoor heated swimming pool on a winter's day but it is still never than much. I know because I used to swim in one!

    The physics might not be as simple as you claim it to be Bunbury.
    Reply With Quote  
     

  71. #70  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Quote Originally Posted by galexander
    Have you ever seen clouds of steam rising from a lake as it is heated in the Sun's rays?

    I have not.

    Okay you will get some steam rising from an outdoor heated swimming pool on a winter's day but it is still never than much. I know because I used to swim in one!
    Steam is an invisible gas, so no I have never seen it rising from a lake. I have however often seen clouds of condensed water vapor rising from lakes, rivers, ponds, underwear on a clothesline and cups of tea.

    The physics might not be as simple as you claim it to be Bunbury.
    I have never claimed physics to be simple, and in fact it's mostly thermodynamics which is based on physics. It takes some effort to understand the laws of thermodynamics and understand how they apply to everyday things such as the evaporation of water, and that seems to be your problem. You can't be bothered to make the effort and you come back here with your erroneous beliefs based on your experience in a swimming pool. You do not believe it is possible to get that much evaporation from a cooling tower without boiling? What you don't get is that there is a group of people called engineers who understand the thermodynamic principles and cleverly apply them to design and build machines that get the maximum amount of usefulness out of whatever materials and energy are are economically available. Swimming pools are not designed to maximize evaporation. Cooling towers are.
    Reply With Quote  
     

  72. #71  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,046
    Quote Originally Posted by hubis
    Quote Originally Posted by Harold14370
    Quote Originally Posted by hubis
    I m not exaggerating, am I?
    Yes, I think you are. It's not going to be anywhere near the scale of Chernobyl. I don't think there will be any radiation related deaths, and no other countries will be affected.
    but mate, 4 plants are faulty, four reactors are in danger.. thats worst than ever before.. dunno.. lets hope they fill those pools with enough water today and electricity back too
    Quote Originally Posted by hubis
    Fukushima nuke crisis - Chernobyl on steroids
    http://www.youtube.com/watch?v=R7JvuUwpq40

    I so agree.. too slow respond on such a serious disaster.. apocalyptic situation
    If you don't know, the fundamental difference between Chernobyl and most reactors used in Japan and the USA is that the moderator in the nuclear reaction was Graphite in Chernobyl and Water in Japanese and American reactors.

    If the reaction gets out of hand and water is your moderator, then the water evaporates and the reaction stops (at least the chain reaction part of it, which is the really dangerous part). The reaction cannot proceed without a moderator. The problem with using graphite as the moderator is that it has the same boiling point as a diamond.

    Anyway, that's just so you realizes that Fukushima is *not* Chernobyl on steroids. It doesn't have now, nor could it ever have, the potential to do what Chernobyl did.
    Some clocks are only right twice a day, but they are still right when they are right.
    Reply With Quote  
     

  73. #72  
    Forum Freshman
    Join Date
    Mar 2011
    Posts
    7
    Ok it looks its not gonna blow like..but the crisis still could go on for months and with such a 1000 - 100,000 than normal radiation levels, it doesn't look promising for the future of that area.
    Very slow and not so successful repair attempts but WHY?? Looks like they are just not that skilled!?

    Even they fix it soon, land and sea are contaminated for ages!

    well, if I bring a jot of something else than science here, I would say.. well done nature, they shouldn't be killing any more whales at least!

    but I m afraid this will be more trouble since radiation is spread
    Reply With Quote  
     

  74. #73  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    Quote Originally Posted by galexander
    Have you ever seen clouds of steam rising from a lake as it is heated in the Sun's rays?

    I have not.

    Okay you will get some steam rising from an outdoor heated swimming pool on a winter's day but it is still never than much. I know because I used to swim in one!
    Steam is an invisible gas, so no I have never seen it rising from a lake. I have however often seen clouds of condensed water vapor rising from lakes, rivers, ponds, underwear on a clothesline and cups of tea.

    The physics might not be as simple as you claim it to be Bunbury.
    I have never claimed physics to be simple, and in fact it's mostly thermodynamics which is based on physics. It takes some effort to understand the laws of thermodynamics and understand how they apply to everyday things such as the evaporation of water, and that seems to be your problem. You can't be bothered to make the effort and you come back here with your erroneous beliefs based on your experience in a swimming pool. You do not believe it is possible to get that much evaporation from a cooling tower without boiling? What you don't get is that there is a group of people called engineers who understand the thermodynamic principles and cleverly apply them to design and build machines that get the maximum amount of usefulness out of whatever materials and energy are are economically available. Swimming pools are not designed to maximize evaporation. Cooling towers are.
    Yes but the "clouds of condensed water vapour" you have seen rising from lakes, rivers, ponds, underwear on a clothesline and cups of tea, do not produce the columns that rise up into the clouds in the sky as you see above cooling towers.

    Please explain the difference.

    You point out the following:

    Swimming pools are not designed to maximize evaporation. Cooling towers are.
    Please explain what special properties cooling towers have which maximizes evaporation.
    Reply With Quote  
     

  75. #74  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by kojax
    Quote Originally Posted by hubis
    Quote Originally Posted by Harold14370
    Quote Originally Posted by hubis
    I m not exaggerating, am I?
    Yes, I think you are. It's not going to be anywhere near the scale of Chernobyl. I don't think there will be any radiation related deaths, and no other countries will be affected.
    but mate, 4 plants are faulty, four reactors are in danger.. thats worst than ever before.. dunno.. lets hope they fill those pools with enough water today and electricity back too
    Quote Originally Posted by hubis
    Fukushima nuke crisis - Chernobyl on steroids
    http://www.youtube.com/watch?v=R7JvuUwpq40

    I so agree.. too slow respond on such a serious disaster.. apocalyptic situation
    If you don't know, the fundamental difference between Chernobyl and most reactors used in Japan and the USA is that the moderator in the nuclear reaction was Graphite in Chernobyl and Water in Japanese and American reactors.

    If the reaction gets out of hand and water is your moderator, then the water evaporates and the reaction stops (at least the chain reaction part of it, which is the really dangerous part). The reaction cannot proceed without a moderator. The problem with using graphite as the moderator is that it has the same boiling point as a diamond.

    Anyway, that's just so you realizes that Fukushima is *not* Chernobyl on steroids. It doesn't have now, nor could it ever have, the potential to do what Chernobyl did.
    If Fukushima is safe because water is the moderator and once all the water has evaporated into steam the reactor will automatically go into shut down, why all the effort to keep the reactor core dowsed in water?

    Surely they are just prolonging the problem by dowsing it in so much water to keep it cool?
    Reply With Quote  
     

  76. #75  
    Comet Dust Collector Moderator
    Join Date
    Mar 2011
    Location
    New Jersey, USA
    Posts
    2,848
    Since you appear to be completely ignnorant about what you are talking about (Cooling Towers) why not take a few minutes of searching to get a clue? I don't mean that in a personal way, it's just obviously true, so take the time!

    Here's a good starting point....
    It's a pretty good intro to the subject.

    http://en.wikipedia.org/wiki/Cooling_tower
    Reply With Quote  
     

  77. #76  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,325
    Quote Originally Posted by galexander

    Yes but the "clouds of condensed water vapour" you have seen rising from lakes, rivers, ponds, underwear on a clothesline and cups of tea, do not produce the columns that rise up into the clouds in the sky as you see above cooling towers.
    Actually if warm enough in an unstable environment that exactly what happens. Buffalo New York receives an extra hundred of inches a year from convection driving by "clouds of condensed water vapor" off the warmer lake Erie and Ontario. Other places near the great lakes do as well. Look at the satillite picture. These are much larger example than cooling towers.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  78. #77  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by MeteorWayne
    Since you appear to be completely ignnorant about what you are talking about (Cooling Towers) why not take a few minutes of searching to get a clue? I don't mean that in a personal way, it's just obviously true, so take the time!

    Here's a good starting point....
    It's a pretty good intro to the subject.

    http://en.wikipedia.org/wiki/Cooling_tower







    Why can't this Drax owned coal fired power station simply just burn less coal and avoid having to use these rather ugly "Cooling Towers"?

    It's not just an eyesore, it's a complete waste of time, money, and it's bad for the environment.

    Please explain to me, with all your scientific wisdom, why a coal or gas fired power station needs so many "Cooling Towers".
    Reply With Quote  
     

  79. #78  
    Comet Dust Collector Moderator
    Join Date
    Mar 2011
    Location
    New Jersey, USA
    Posts
    2,848
    To cool the water?

    If you didn't cool the water, the power plant would be less efficient.

    If you burn less coal, oil, or natural gas, or fission less Uranium/Plutonium/Thorium, you create less electricity.

    If you don't cool the water, you have to burn more coal, oil, or natural gas, or fission more Uranium/Plutonium/Thorium

    That is, after the point of a power plant! Making electricity.

    We can barely keep up with the electrical demands on any continent.

    Want to help?

    Use less electricity.

    {I have a suggestion, but I'll save it for now}
    Reply With Quote  
     

  80. #79  
    Veracity Vigilante inow's Avatar
    Join Date
    Oct 2009
    Location
    Austin, TX
    Posts
    3,500
    Let me paraphrase galexander's arguments in these threads:

    "Hey, look! Here's a picture of condensation on some cooling towers. I don't get it, but be scared. It must be bad, so there."
    Reply With Quote  
     

  81. #80  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,169
    Quote Originally Posted by galexander
    Why can't this Drax owned coal fired power station simply just burn less coal and avoid having to use these rather ugly "Cooling Towers"?
    If you were to turn your computer off this would place less of a demand on the electricity generators. True, this would only be a secondary benefit. The primary benefit would be the absence of your ignorant statements on this forum.

    Quote Originally Posted by galexander
    It's not just an eyesore,.
    I think they are rather grand. 'Eyesore' is a subjective word. Before the Victorians the Scottish Highlands were thought to be ugly, ghastly places. Now we rejoice in the scenery. Buzz Aldrin captured the dichotomy perfectly in his description of the lunar landscape: magnificent desolation.

    Quote Originally Posted by galexander
    it's a complete waste of time, money, .
    So how do you propose to meet the power needs of modern civilisation?

    Quote Originally Posted by galexander
    it's bad for the environment.
    .
    Fossil fuel power stations are certainly bad for the environment. In what way, however, are the cooling towers bad for the environment. I grant you a shortsighted swan might fly into one and sustain a concussion, but other than that I can see no significant environmental impact.

    Quote Originally Posted by galexander
    Please explain to me, with all your scientific wisdom, why a coal or gas fired power station needs so many "Cooling Towers".
    Because there is a lot of waste heat to deal with. I think this has been explained to you several times already. What lies at the heart of your comprehension problem?
    Reply With Quote  
     

  82. #81  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by galexander
    Why can't this Drax owned coal fired power station simply just burn less coal and avoid having to use these rather ugly "Cooling Towers"?
    If you were to turn your computer off this would place less of a demand on the electricity generators. True, this would only be a secondary benefit. The primary benefit would be the absence of your ignorant statements on this forum.

    Quote Originally Posted by galexander
    It's not just an eyesore,.
    I think they are rather grand. 'Eyesore' is a subjective word. Before the Victorians the Scottish Highlands were thought to be ugly, ghastly places. Now we rejoice in the scenery. Buzz Aldrin captured the dichotomy perfectly in his description of the lunar landscape: magnificent desolation.

    Quote Originally Posted by galexander
    it's a complete waste of time, money, .
    So how do you propose to meet the power needs of modern civilisation?

    Quote Originally Posted by galexander
    it's bad for the environment.
    .
    Fossil fuel power stations are certainly bad for the environment. In what way, however, are the cooling towers bad for the environment. I grant you a shortsighted swan might fly into one and sustain a concussion, but other than that I can see no significant environmental impact.

    Quote Originally Posted by galexander
    Please explain to me, with all your scientific wisdom, why a coal or gas fired power station needs so many "Cooling Towers".
    Because there is a lot of waste heat to deal with. I think this has been explained to you several times already. What lies at the heart of your comprehension problem?
    But none of you have bothered to answer the simple question I have asked:

    Why do coal and gas fired power station need so many cooling towers?

    Accusing me of being ignorant is NO ANSWER!


    Reply With Quote  
     

  83. #82  
    Comet Dust Collector Moderator
    Join Date
    Mar 2011
    Location
    New Jersey, USA
    Posts
    2,848
    TO COOL THE WATER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    How much more simple of an answer do you need?

    People have repeatedly (apparently, wasted) their time trying to explain the reasons for this. Either you haven't read the links, or they are far beyond your ability to comprehend.

    It's pointless trying to explain it to a person (or troll) who deliberately makes no effort to understand.
    Reply With Quote  
     

  84. #83  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    Please explain what special properties cooling towers have which maximizes evaporation.
    Read this book. It's free!

    http://spxcooling.com/pdf/Cooling-To...ndamentals.pdf
    Reply With Quote  
     

  85. #84  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by MeteorWayne
    TO COOL THE WATER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    How much more simple of an answer do you need?

    People have repeatedly (apparently, wasted) their time trying to explain the reasons for this. Either you haven't read the links, or they are far beyond your ability to comprehend.

    It's pointless trying to explain it to a person (or troll) who deliberately makes no effort to understand.
    So the purpose of the Cooling Towers is to cool the water.

    How is this an answer?

    I thought the idea was to HEAT the water not cool it!
    Reply With Quote  
     

  86. #85  
    Forum Radioactive Isotope Paleoichneum's Avatar
    Join Date
    Oct 2008
    Location
    Washington State, USA
    Posts
    4,627
    Quote Originally Posted by galexander
    Quote Originally Posted by MeteorWayne
    TO COOL THE WATER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    How much more simple of an answer do you need?

    People have repeatedly (apparently, wasted) their time trying to explain the reasons for this. Either you haven't read the links, or they are far beyond your ability to comprehend.

    It's pointless trying to explain it to a person (or troll) who deliberately makes no effort to understand.
    So the purpose of the Cooling Towers is to cool the water.

    How is this an answer?

    I thought the idea was to HEAT the water not cool it!
    Are you purposely being obtuse??

    The coal/oil is taken to the plant and burned, that burning produces heat which heats water in massive tanks. the water boils into steam creating pressure that turns the dynamos to generate electricity. The water is the COOLED in the cooling towers and returned to the water source and/or reused in the heating process.

    Why are you sooooo weirded out by these towers anyways?
    Reply With Quote  
     

  87. #86  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Paleoichneum
    Quote Originally Posted by galexander
    Quote Originally Posted by MeteorWayne
    TO COOL THE WATER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    How much more simple of an answer do you need?

    People have repeatedly (apparently, wasted) their time trying to explain the reasons for this. Either you haven't read the links, or they are far beyond your ability to comprehend.

    It's pointless trying to explain it to a person (or troll) who deliberately makes no effort to understand.
    So the purpose of the Cooling Towers is to cool the water.

    How is this an answer?

    I thought the idea was to HEAT the water not cool it!
    Are you purposely being obtuse??

    The coal/oil is taken to the plant and burned, that burning produces heat which heats water in massive tanks. the water boils into steam creating pressure that turns the dynamos to generate electricity. The water is the COOLED in the cooling towers and returned to the water source and/or reused in the heating process.

    Why are you sooooo weirded out by these towers anyways?
    So what you are trying to say is that the Cooling Towers cool the water supplied to the condensers which condense the steam produced by the main heat source?

    I admit I am not an expert on thermodynamics, but what you are saying is that simple evaporation of water in air at ambient temperatures is able in turn to condense steam causing a huge enough suction effect to drive the turbines?

    But how quickly does water at temperatures of 26-35C evaporate in air at ambient temperatures?

    To use the comparison with clothes drying it can take absolutely hours and hours just to dry a single wet shirt!



    Reply With Quote  
     

  88. #87  
    Forum Radioactive Isotope Paleoichneum's Avatar
    Join Date
    Oct 2008
    Location
    Washington State, USA
    Posts
    4,627
    Quote Originally Posted by galexander
    Quote Originally Posted by Paleoichneum
    Quote Originally Posted by galexander
    Quote Originally Posted by MeteorWayne
    TO COOL THE WATER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    How much more simple of an answer do you need?

    People have repeatedly (apparently, wasted) their time trying to explain the reasons for this. Either you haven't read the links, or they are far beyond your ability to comprehend.

    It's pointless trying to explain it to a person (or troll) who deliberately makes no effort to understand.
    So the purpose of the Cooling Towers is to cool the water.

    How is this an answer?

    I thought the idea was to HEAT the water not cool it!
    Are you purposely being obtuse??

    The coal/oil is taken to the plant and burned, that burning produces heat which heats water in massive tanks. the water boils into steam creating pressure that turns the dynamos to generate electricity. The water is the COOLED in the cooling towers and returned to the water source and/or reused in the heating process.

    Why are you sooooo weirded out by these towers anyways?
    So what you are trying to say is that the Cooling Towers cool the water supplied to the condensers which condense the steam produced by the main heat source?

    I admit I am not an expert on thermodynamics, but what you are saying is that simple evaporation of water in air at ambient temperatures is able in turn to condense steam causing a huge enough suction effect to drive the turbines?

    But how quickly does water at temperatures of 26-35C evaporate in air at ambient temperatures?

    To use the comparison with clothes drying it can take absolutely hours and hours just to dry a single wet shirt!
    No that is not what I said, and I am beginning to wonder if you are trolling purposely.


    Here is a very relevent paragraph from the wiki page on cooling towers that you ahve been linked to several times now:
    In a wet cooling tower (or Open Circuit Cooling Tower), the warm water can be cooled to a temperature lower than the ambient air dry-bulb temperature, if the air is relatively dry. (see: dew point and psychrometrics). As ambient air is drawn past a flow of water, an small portion of the water evaporate, the energy required by that portion of the water to evaporate is taken from the remaining mass of water reducing his temperature (aproximately by 970 BTU for each pound of evaporated water). Evaporation results in saturated air conditions, lowering the temperature of the water process by the tower to a value close to wet bulb air temperature, which is lower than the ambient dry bulb air temperature, the difference determined by the humidity of the ambient air.

    To achieve better performance (more cooling), a medium called fill is used to increase the surface area and the time of contact between the air and water flows. Splash fill consists of material placed to interrupt the water flow causing splashing. Film fill is composed of thin sheets of material (usually PVC) upon which the water flows. Both methods create increased surface area and time of contact between the fluid (water) and the gas (air).
    Basically the longer the how water is exposed to the air and the more surface area present in that exposure, the faster the evaporation time.
    Reply With Quote  
     

  89. #88  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,325
    To use the comparison with clothes drying it can take absolutely hours and hours just to dry a single wet shirt!
    That is true, but a cooling tower isn't trying to dry all the water away, it is cooling to re condense the water. That T-shirt will cool to the wet-bulb temperature in just a couple minutes.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  90. #89  
    Comet Dust Collector Moderator
    Join Date
    Mar 2011
    Location
    New Jersey, USA
    Posts
    2,848
    Quote Originally Posted by galexander

    So what you are trying to say is that the Cooling Towers cool the water supplied to the condensers which condense the steam produced by the main heat source?

    I admit I am not an expert on thermodynamics, but what you are saying is that simple evaporation of water in air at ambient temperatures is able in turn to condense steam causing a huge enough suction effect to drive the turbines?
    Now you are trolling, deliberately ignorant. NO ONE has said that the suction of the cooling drives the turbine..it's such a stupid statement it boggles the mind.

    The turbines are driven by the steam pressure created by the burning of fossil fuels, or the fission of fuel. The coolling towers cool the water feeding into the system to make it more efficient. To suggest anything else is way beyond obtuse... it's pure trolling, or complete and total ignorance. Sorry, them's the facts.
    Reply With Quote  
     

  91. #90  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,169
    Quote Originally Posted by galexander
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by galexander
    Please explain to me, with all your scientific wisdom, why a coal or gas fired power station needs so many "Cooling Towers".
    Because there is a lot of waste heat to deal with. I think this has been explained to you several times already. What lies at the heart of your comprehension problem?
    But none of you have bothered to answer the simple question I have asked:

    Why do coal and gas fired power station need so many cooling towers?

    Accusing me of being ignorant is NO ANSWER!
    Well, you may not be ignorant, but you sure as **** can't read. Not only has the question be answerd multiple times in this thread, but I provided an answer inches away from where you say you haven't received one. With ignorant responses like that it is very difficult not accuse you of being ignorant.

    Now here's a thing. Ignorance is not of itself a bad thing. We are all ignorant of most things. What is unforgiveable is persistent, willful ignorance, such as you display here. The two commonest epxlanations for this are 1) a distorted, sociopathic personality, 2) gross stupidity. I'm leaning to the latter in your case. What's your own explanation?
    Reply With Quote  
     

  92. #91  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by galexander
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by galexander
    Please explain to me, with all your scientific wisdom, why a coal or gas fired power station needs so many "Cooling Towers".
    Because there is a lot of waste heat to deal with. I think this has been explained to you several times already. What lies at the heart of your comprehension problem?
    But none of you have bothered to answer the simple question I have asked:

    Why do coal and gas fired power station need so many cooling towers?

    Accusing me of being ignorant is NO ANSWER!
    Well, you may not be ignorant, but you sure as **** can't read. Not only has the question be answerd multiple times in this thread, but I provided an answer inches away from where you say you haven't received one. With ignorant responses like that it is very difficult not accuse you of being ignorant.

    Now here's a thing. Ignorance is not of itself a bad thing. We are all ignorant of most things. What is unforgiveable is persistent, willful ignorance, such as you display here. The two commonest epxlanations for this are 1) a distorted, sociopathic personality, 2) gross stupidity. I'm leaning to the latter in your case. What's your own explanation?
    The problem is you are not being clear enough and specific enough.

    Define what you mean by Waste Heat and where does the Waste Heat come from?

    Why is the heat wasted?
    Reply With Quote  
     

  93. #92  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by MeteorWayne
    Quote Originally Posted by galexander

    So what you are trying to say is that the Cooling Towers cool the water supplied to the condensers which condense the steam produced by the main heat source?

    I admit I am not an expert on thermodynamics, but what you are saying is that simple evaporation of water in air at ambient temperatures is able in turn to condense steam causing a huge enough suction effect to drive the turbines?
    Now you are trolling, deliberately ignorant. NO ONE has said that the suction of the cooling drives the turbine..it's such a stupid statement it boggles the mind.

    The turbines are driven by the steam pressure created by the burning of fossil fuels, or the fission of fuel. The coolling towers cool the water feeding into the system to make it more efficient. To suggest anything else is way beyond obtuse... it's pure trolling, or complete and total ignorance. Sorry, them's the facts.
    The reason why a steam engine is driven is because of the pressure differential between the pressurized steam and the atmospheric pressure at the outlet.

    In the Rankine cycle there is no outlet, the system is sealed. The only pressure differential which occurs therefore is when the steam condenses into water in the Condenser.

    Without this pressure differential caused by the condensation in the Condenser the turbines would not turn.

    Q.E.D.
    Reply With Quote  
     

  94. #93  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,169
    Quote Originally Posted by galexander
    The problem is you are not being clear enough and specific enough.
    And that problem was initiated by your arrogant posture from almost your very first post. If you talk like an individual who understands science, engineering, industrial processes, power generation, thermodynamics etc it will be intially assumed that you can be responded to without an explanation of terminology. It will be assumed initially that you are using terms in a recognised manner and that you are familiar with accepted theories and observed facts. It is not expected that you have a fifth grade understanding and so it will be very easy to talk over your head. Don't blame me or anyone else for that. It stemmed from, as noted above, your arrogant posturing.

    Any conversion process, where we change one form of energy to another, will be inefficient. That inefficiency is expressed as heat, specifically waste heat. Do you require more? I can't even understand what it is you aren't understanding about that. (And before you think of asking me to 'lose the attitude', I'll do so the moment I see some evidence that you have done so.)
    Reply With Quote  
     

  95. #94  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by galexander
    The problem is you are not being clear enough and specific enough.
    And that problem was initiated by your arrogant posture from almost your very first post. If you talk like an individual who understands science, engineering, industrial processes, power generation, thermodynamics etc it will be intially assumed that you can be responded to without an explanation of terminology. It will be assumed initially that you are using terms in a recognised manner and that you are familiar with accepted theories and observed facts. It is not expected that you have a fifth grade understanding and so it will be very easy to talk over your head. Don't blame me or anyone else for that. It stemmed from, as noted above, your arrogant posturing.

    Any conversion process, where we change one form of energy to another, will be inefficient. That inefficiency is expressed as heat, specifically waste heat. Do you require more? I can't even understand what it is you aren't understanding about that. (And before you think of asking me to 'lose the attitude', I'll do so the moment I see some evidence that you have done so.)
    Oh come on Ophiolite, you do have the tendency to be a little pompous now and then.

    It doesn't matter how confident with yourself you sound to others or how much of an expert you are at you given subject area of study, NOBODY KNOWS EVERYTHING. And that means absolutely nobody, even the very best of us.

    And you still didn't answer my question which leaves me with the reflection that even Ophiolite doesn't know everything either!

    What is the waste heat exactly? I put the question to you are the Cooling Towers cooling the water used in the Condensers? This is what I mean by being more specific.
    Reply With Quote  
     

  96. #95  
    Veracity Vigilante inow's Avatar
    Join Date
    Oct 2009
    Location
    Austin, TX
    Posts
    3,500
    Quote Originally Posted by MeteorWayne
    Now you are trolling, deliberately ignorant. ... it's pure trolling, or complete and total ignorance. Sorry, them's the facts.
    Don't be so sure. I think he really is a dumbshit.
    Reply With Quote  
     

  97. #96  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    I don't think you are trolling, but it is frustrating that you ask the same questions over and over. Do you actually read and try to absorb the answers that people have given? I offer this one last time then I'm done here. Take it or leave it.

    The Rankine cycle can be open or closed. In the case of power turbines it is closed because we need to conserve the water, and as you say, we need to pull the pressure down below atmospheric in order to get the most work out of the steam.

    The pressure differential that drives the turbines is not just the differential between atmospheric and the condenser vacuum; it is the differential between the boiler outlet, which might be 40 bar, and the condenser, which might be a fraction of 1 bar. And in fact it is not just the pressure; it is the total heat of the boiler steam, which is usually superheated. You have to consider the enthalpy of the superheated steam minus the enthalpy of the vacuum steam to see how much energy has been removed from the steam in going through the turbines.

    The energy comes from the combustion of fuel in a fossil plant. Heat of combustion is transferred to water by radiant and convective heat transfer in the various parts of the boiler. There has to be a temperature difference for heat transfer to occur (2nd. Law). This means the flue gases must leave the furnace and enter the chimney stack at a temperature that is higher than the temperature of the water and steam. The fuel and air that were initially burned were originally at or near atmospheric temperature, but you cannot return the flue gas to atmospheric temperature. This raised temperature of the flue gas represents one part of the waste heat that cannot be recovered.

    At the other end of the cycle, the condenser, the object is to get the pressure as low as practically possible, but again the 2nd Law says you must have a temperature difference between your coolant and the condensing steam so the temperature in the condenser will be higher than the seawater, or the air, or the cooling tower water that you are using to condense the steam. The coolant, whatever it is, picks up heat from the condensing steam and dumps it in the air or the river in the ocean. If cooling towers are being used the water that goes through the tubes in the condenser picks up heat from the steam and in the process becomes warmer. When it goes to the cooling tower the warm water contacts cool air and some of it (around 5%) evaporates, taking with it the latent heat of evaporation and thus cooling the remaining 95% so that it can go back to the condenser and be used again. The warmed air and evaporated water that rises from the cooling tower is the other major component of the waste heat. It is energy that you put in by burning fuel but you could not capture in the spinning turbines, so it is wasted, like the heat that went up the stack. Incidentally, nukes do not have stacks so their waste heat all goes into the cooling water, which is why they need more cooling water and bigger cooling towers than fossil plants.

    There are other inefficiencies in the plant that waste additional heat. For example, there is an air removal system that uses steam or some of the generated electricity to suck air out of the system. And of course there is the boiler feedwater pump that raises the pressure of the condensed steam coming from the condenser so that it can get back into the boiler. This pump can be electrically driven, or driven by a smaller steam turbine. Either way it represents an unavoidable inefficiency in the cycle.
    Reply With Quote  
     

  98. #97  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Bunbury
    I don't think you are trolling, but it is frustrating that you ask the same questions over and over. Do you actually read and try to absorb the answers that people have given? I offer this one last time then I'm done here. Take it or leave it.

    The Rankine cycle can be open or closed. In the case of power turbines it is closed because we need to conserve the water, and as you say, we need to pull the pressure down below atmospheric in order to get the most work out of the steam.

    The pressure differential that drives the turbines is not just the differential between atmospheric and the condenser vacuum; it is the differential between the boiler outlet, which might be 40 bar, and the condenser, which might be a fraction of 1 bar. And in fact it is not just the pressure; it is the total heat of the boiler steam, which is usually superheated. You have to consider the enthalpy of the superheated steam minus the enthalpy of the vacuum steam to see how much energy has been removed from the steam in going through the turbines.

    The energy comes from the combustion of fuel in a fossil plant. Heat of combustion is transferred to water by radiant and convective heat transfer in the various parts of the boiler. There has to be a temperature difference for heat transfer to occur (2nd. Law). This means the flue gases must leave the furnace and enter the chimney stack at a temperature that is higher than the temperature of the water and steam. The fuel and air that were initially burned were originally at or near atmospheric temperature, but you cannot return the flue gas to atmospheric temperature. This raised temperature of the flue gas represents one part of the waste heat that cannot be recovered.

    At the other end of the cycle, the condenser, the object is to get the pressure as low as practically possible, but again the 2nd Law says you must have a temperature difference between your coolant and the condensing steam so the temperature in the condenser will be higher than the seawater, or the air, or the cooling tower water that you are using to condense the steam. The coolant, whatever it is, picks up heat from the condensing steam and dumps it in the air or the river in the ocean. If cooling towers are being used the water that goes through the tubes in the condenser picks up heat from the steam and in the process becomes warmer. When it goes to the cooling tower the warm water contacts cool air and some of it (around 5%) evaporates, taking with it the latent heat of evaporation and thus cooling the remaining 95% so that it can go back to the condenser and be used again. The warmed air and evaporated water that rises from the cooling tower is the other major component of the waste heat. It is energy that you put in by burning fuel but you could not capture in the spinning turbines, so it is wasted, like the heat that went up the stack. Incidentally, nukes do not have stacks so their waste heat all goes into the cooling water, which is why they need more cooling water and bigger cooling towers than fossil plants.

    There are other inefficiencies in the plant that waste additional heat. For example, there is an air removal system that uses steam or some of the generated electricity to suck air out of the system. And of course there is the boiler feedwater pump that raises the pressure of the condensed steam coming from the condenser so that it can get back into the boiler. This pump can be electrically driven, or driven by a smaller steam turbine. Either way it represents an unavoidable inefficiency in the cycle.
    Two points from the above immediately strike me.

    You say the following:

    The pressure differential that drives the turbines is not just the differential between atmospheric and the condenser vacuum; it is the differential between the boiler outlet, which might be 40 bar, and the condenser, which might be a fraction of 1 bar.
    But what has "atmospheric" pressure to do with it in a 'closed' system? The pressure provided by the boiler would simply equilibriate throughout a closed system so I stand by my point that what drives the turbines is the negative pressure supplied by the Condenser.

    You also say the boiler steam is superheated but that would tend to reduce the efficiency of the Condenser which now has to cool the steam even further to below the point of vaporisation.

    And considering the principle Condensers are based upon, it is still my honest opinion they have their work cut out.

    Looking at the diagram below you might get some condensation appearing on the "lukewarm" water pipes but you may well have to wait quite sometime before you get even a bucket full!





    Another problem I am still not happy with is that you are having to pump the condensed water out of a system which is under negative pressure and don't forget this is the same negative pressure which is driving the turbines.........

    It almost seems like a perpetual motion device, though one which cheats.
    Reply With Quote  
     

  99. #98  
    Forum Isotope Bunbury's Avatar
    Join Date
    Sep 2007
    Location
    Colorado
    Posts
    2,590
    I have explained it as best I can. Read some books.
    Reply With Quote  
     

  100. #99  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,325
    I can see why folks are frustrated. A forum isn't a good way to learn basics of thermodynamics.
    --

    But try to think of it this way. After spinning the turbines you get a lot of steam that's no longer in a useful form to do any more work. You can dump all that steam directly into the environment, much like a 19th century locomotive, and wasteful of water, or leverage the environment to cool it down using the cooling towers so you retain most of the water.

    At that point you can re-use the water, use energy to turn it back into high-pressure steam so it can in-turn be used to do work to turn turbines to produce electricity etc.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  101. #100  
    Forum Masters Degree
    Join Date
    Nov 2010
    Location
    UNITED KINGDOM
    Posts
    627
    Quote Originally Posted by Lynx_Fox
    It is creating the suction effect which is driving the turbine.
    There is no such thing as suction in physics.

    I'm not sure why you're dwelling on this aspect; it has virtually nothing to do with reason most energy plants need cooling towers.
    Reply With Quote  
     

Page 1 of 2 12 LastLast
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •