Modelling and performance analysis of power system in gas engine-driven heat pump

The gas engine-driven heat pump (GHP) is an energy-saving and environmentally friendly technology. In pre-vious studies, there were few dynamic quantitative analyses of gas engines' exergy efficiency (riex,e) and waste heat recovery (Qrec), which are essential but not easy to achieve. This paper establishes the multivariate regression equations of related physical quantities according to the manufacturer or experimental data. Based on the above, the effect of the engine's two-dimensional (2-D) factors on thermal efficiency (rie), riex,e, and Qrec are analyzed, respectively. Since the scroll compressor manufacturer could not provide data and selection software, a general modelling method was proposed based on experimental data and gain the quantitative analysis of me-chanical (rim) and exergy efficiency, which is also less in previous studies but essential. In addition, the primary performance of GHP is also analyzed through the coupled model of the power system. The main results show that: rie and Qrec are positively correlated with the engine's load, while riex,e is the contrary. Using a higher low heating value (LHV) gas can increase rie and Qrec by 3.38 % and 1.12 kW, respectively, compared with a lower one. The riex,sc and rim of the compressor are positively correlated with the heat pump load, varying in 55.51-77.12 % and 68.20-97.52 %, respectively. In summary, the power system model established in this paper can supplement the lack of quantitative analysis of main parameters in the previous GHP, and the modelling method of the compressor is also generally applicable to other heat pump systems.