Energy Grade Balance of Gas Engine-Driven Heat Pump

Gas Engine-driven heat pump (GEHP) is the compressed heat pump driven by gas engine. For an R-134a GEHP system at 2°C evaporator and 50°C condensing temperature, analyses based on the first law of thermodynamics, exergy and energy grade are processed. Comparing to other heating devices, such as electric driven heat pump, coal fired boiler, electric boiler and gas fired boiler, GEHP has higher performances, the primary energy ratio (PER) of which is 1.76, the exergy efficiency is 0.291 and the energy grade balance efficiency is 0.394. The results of the energy grade balance analysis are consistent with that of the first law thermodynamics analysis and the exergy analysis. Since the anergy plays an important role when heat pump extracts heat from the surroundings, energy grade balance analysis, which takes into account the anergy, is suggested to evaluate the performance of heat pump.