Study On The Characteristics Of The Coupling System Of CO₂ Heat Pump With Solar-air Two-stage Compression

Nowadays,with the rapid development of society,the energy consumption is increasing day by day,and the problem of environmental pollution has been paid more and more attention by the society.Heat pump technology using clean and renewable energy as a heat source has made significant contributions to energy conservation,emission reduction,environmental protection,etc.,and has become a research hotspot.Solar energy and air have become important targets for heat pump heat sources as renewable energy sources.However,the decline in the performance of air source heat pumps in low temperature environments and the impact of solar resources on regional and climatic factors have limited the use of air sources and solar heat pumps.This paper proposes a solar-air composite heat source heat pump based on the composite heat source heat exchanger,which reduces the impact of outdoor ambient temperature and solar energy on system performance,complements the advantages of the two,and gives full play to the performance of the system.Social benefits and use value.In this paper,a component model and a system model of a solar-air composite heat source dual-stage compression CO₂ heat pump water heater system are established through simulation.The numerical simulation method is used to analyze the characteristics of the system under different ambient temperature,solar hot water flow rate and solar hot water temperature.Use the test bench to perform a single air source mode performance test on the heat pump system under several ambient temperature conditions?-12,-9,-6,-3,0,3,6,9,12°C?.The comparative analysis of the simulation data shows that the heating performance error of the two is within 15%,and the model has high reliability.By simulating the system under different outdoor ambient temperature conditions,the results show that the performance of the heat pump system in the composite heat source mode is significantly better than that of the single air source mode,and the advantages become more obvious as the ambient temperature decreases.When the ambient temperature drops to-15°C and the solar hot water flow rate is 0.6m³/h,the heating capacity of the system is increased by22.6%,the COP is increased by 25.9%,and the air cooler outlet temperature is increased by11.54?within the compound heat transfer temperature range.The simulation shows that the temperature difference between solar hot water and air has a certain effect on the performance of the system.The reasonable selection of solar hot water temperature according to the outdoor environment temperature is the key to ensure the efficient operation of the system.