Thread: Boiler Efficiency

Hi there,

Im completing a question for college but im having a bit of a problem.

I am looking to work out the efficiency of a boiler. I have the following info - oil consumption, gas calorific value, oil density, average water flow rate and the change in water temperatures.

I have the following equation



Mass Flow Rate of Water x Spec. Heat Capacity of Water x deltaT

divided by:

Mass Flow Rate of Fuel x Gross Calorific Value





The question is, im unsure as to what units I should use in my equation to work out the total efficiency.

Also is the 'mass flow rate of fuel' the same as 'oil consumption'?

I know that the efficiency is unit-less.

Any help would be most appreciated



Kind Regards

"Oil consumption" could mean a lot of things. If it's a volume flow rate, you will have to multiply by the density to get the mass flow rate.

Do you mean "gas calorific value" or "gross calorific value?"

I suppose "gas calorific value" could mean the heat going up the chimney in the combustion exhaust gas. So then to get the gross calorific value you would add the gas calorific value to the heat being added to the water.