How To Calculate Waste Heat Recovery Boiler Thermal Efficiency

Boiler thermal efficiency indicates the heat exchangers effectiveness to transfer heat from the combustion process to the water or steam in a boiler, exclusive the radiation and convection losses. There are two methods to calculate a waste heat recovery boiler thermal efficiency, Positive Balance Test and Anti-Balance Test.

Positive balance test is to directly measure the mass flow, eroded and fuel consumption, low calorific value and others, then in accordance with the ratio to work out the boiler efficiency, that is effective utilized heat and fuel input heat ratio.
Anti-balance test is to determine the efficiency of boiler by testing the heat losses, which include the Q2 flue gas losses, Q3 gas incomplete combustion losses, Q4 solid incomplete combustion losses, Q5 heat radiation losses and Q6 slag ash physical losses, then put the measured heat losses value into the formula to calculate.

In general, we take the anti-balance test to calculate waste heat boiler thermal efficiency. The formular is η= 100-(q2+q3+q4+q5+q6). The key points for calculation is to make sure the heat losses values.

Note that thermal efficiency calculated by the above formula is only theoretical thermal efficiency of waste heat boilers, for the specific boiler thermal efficiency, one can contact us and our engineer can give the accurate value and industrial boiler solutions.