Performance Analysis Of Dual Evaporator Heat Pump And Separate Heat Pipe Coupling System

The air source heat pump has serious frost problem in the winter heating in cold region.The performance of single solar energy heat pump is greatly affected by the fluctuation of solar radiation.So Solar-air energy composite sources heat pump has attracted more and more attention.The composite source heat pump synthetically utilizes solar energy and air energy two kinds of low-grade energy,can overcome all kinds of limitation brought by single heat source,realize advantage complementary,and have great improvement in reliability and stability.As a result,it has been widely used in China.Separate heat pipe is an efficient heat transfer element.It has the characteristics of high heat transfer efficiency,flexible layout,and easy integration with related systems.Therefore,it can be seen in many fields.In order to deepen the research of solar-air energy composite source heat pump,the solar-air energy composite source heat pump system coupled with separated heat pipe technology is studied in this paper.Based on the existing theory and numerical model,a new coupling system of double evaporator heat pump and separated heat pipe is designed and built.The system realizes the comprehensive utilization and complementary advantages of solar energy and air energy.The system has five operating modes:single solar heat pump,air source heat pump,solar-air energy composite source heat pump(including series and parallel),and solar energy separation heat pipe.In combination with the actual situation,the performance test was performed on the three modes of the solar separated heat pipe,the air source heat pump and the solar-air composite source heat pump in the coupling system.The study found that,under the solar separated heat pipe mode,the system pressure,condenser pressure drop,condenser inlet and outlet temperature,system heat supply,heating efficiency,and experimental room temperature are all greatly affected by the solar radiation intensity and are all maintain similar trends with it.In the air source heat pump operation mode,the evaporator inlet temperature,superheat,evaporator pressure drop,condenser pressure drop,compressor input power,system heat supply and heating performance coefficient are all positively correlated with the outdoor temperature,but the compressor compression ratio is Negative correlated with it.In the solar-air energy composite source heat pump mode,the system evaporator inlet temperature,superheat,evaporator pressure drop,compressor input power,system heat supply,and heating performance coefficient are all maintain similar trends with solar radiation intensity and outdoor temperature,and are positively correlated with them.However,the compression ratio has a negative correlation with solar radiation intensity and outdoor temperature.In this paper,the characteristics of three modes in a new type of double evaporator heat pump and separated heat pipe coupling system are investigated,and the effects of outdoor temperature and solar radiation intensity on the important performance parameters of the system in different modes are analyzed.The related experimental data and variation rules can provide the basis for the further optimization design and related research of the new heat pump system,which has a certain reference and guidance significance.