Performance Analysis Of Combined Cycle Driven By Multi Heat Source

Gas engine-driven heat pump(GEHP)is a kind of air conditioning device with the features of highly efficient,energy-saving and environmentally friendly,which can use natural gas effectively to supply heat capacity and cool capacity,at the same time to ease the pressure of electricity,and it is convenient to control,so as a kind of green energy saving equipment,GEHP can be widely used in the future.In this paper,the performance of gas engine heat pump was tested,and based on the higher heat utilization of waste gas,a joint energy supply scheme of traditional gas engine compression heat pump and absorption heat pump was established.The main research contents and results are as follows:Firstly,the working principle and energy balance of the gas engine heat pump system was introduced,and the heat of the engine exhaust gas is reasonably evaluated.The results show that for small gas internal combustion engine,it's not economical to use absorption system to recover the flue gas directly.Combined with the application of high temperature solar collector technology,the 20m2's parabolic trough focusing system(PTC)is proposed as an auxiliary heat source,which drive the absorption heat pump cycle with the engine flue gas together.The heat transfer model of gas heat exchanger and the solar focusing collector model were established,and the coupling condition of two kinds of heat source has been carried on the numerical analysis.Then using Aspen Plus software to establish the technological process of ammonia absorption heat pump cycle.Through the simulation calculation,the impact of the heat source temperature,evaporation temperature,condensation temperature on the performance of the system were analyzed.The results show that only by controlling the heat source temperature under the optimal operating range,can the best performance achieve.At the same time,should raise the evaporation temperature and reduce the condensation temperature under the premise of meet the load.In the end,the energy efficiency of the new combined cycle is changed with the engine speed and the intensity of solar radiation.The higher the solar radiation intensity,the higher the PER of the combined system;Within a certain speed range,the lower the engine speed,the higher the PER,and the increase of PER is more obvious with increase of the radiation intensity.The results show that compared with theprevious gas engine heat pump,the PER of the combined system was significantly increased by 16.9%~38.7% in the winter,21.7%~43.5% in the spring and autumn,and in the summer the value can reach 27%~42.4%.