Heating performance of a parallel gas engine compression-absorption heat pump

Abstract

To achieve cascade utilization of waste heat of gas engine, a parallel gas engine compression-absorption heat pump (GECAHP) combined a compression-type heat pump and an absorption-type heat pump was proposed and modeled. The compression-type heat pump is driven by the motive power from the gas engine and the absorption-type heat pump is activated by the waste heat of exhaust gas. Based on the simplified model, the heating performance of the GECAHP system and the energy-saving potential compared with conventional gas engine heat pump (GEHP) system are simulated. The results show that as the gas engine speed increases from 1500rpm to 2500rpm, the total heating capacity and primary energy consumption increase by 54.5% and 64.9%, respectively, while the primary energy ratio decreases by 5.5%. It has a smaller effect on the performance of GECAHP for exhaust gas outlet temperature compared with the water inlet temperature and ambient air temperature. In this work, the maximum primary energy ratio of GECAHP system is greater than 1.5 considering the energy consumption of the fans and solution pump. Compared with conventional GEHP system, GECAHP system can produce more than 6% of heating capacity and save around 5% of primary energy.