October 7, 2019

Steam System Thermal Cycle Efficiency – A Important Benchmark in the Steam System

A question that all steam system managers need to answer is the steam system thermal cycle efficiency.  The average steam system thermal cycle efficiency is 58%, which means that 42% of the energy that is consumed in the boilers is wasted or loss.  To utilize all the energy input into the boilers is not achievable and the operation will have a few acceptable losses, but a high percentage of losses can be prevented or eliminated.

The total system is shown in Figure No. 1

Total fuel energy or Btu’s input into the boiler to generate the steam


Btu’s that are recovered and delivered back to the boiler plant

  • When benchmarking the thermal cycle, the sensible energy in the condensate and quantity that is delivered back to the boiler is considered the recovered energy.
  • The deaerator uses steam from the main steam line maintain pressure and temperature on the deaerator, therefore can not be the benchmark for recovered condensate.