Study On Integrative Solar/Air Double Source Heat Pump System

Research and development of integrative solar/air double source heat pump system has been done through theoretical research and experiments. The key equipment of solar energy-air source heat pump is heat collect evaporator. Its performance and costs influence heavily on solar energy-air source heat pump system's performance and economy.The high efficiency heat collect evaporator researched in this article should absorb solar energy and air energy high efficiently at the same time. But the optimal structure parameters of heat collector that only absorbs solar energy and only absorbs air energy are different. Convective heat exchange is required be enhanced and air's flow resistance is required be reduced when air energy is absorbed singly. And fins should face the sun which can reduce sun's incident angle and increase sun's direct surface when solar energy is absorbed singly.Theoretical simulation research through computer has been done firstly. The optimum structure parameters and direct solar radiation,total solar radiation under different structural parameters are simulated. And comparative analysis with solar radiation of plat,conventional air source heat pump evaporator exposed directly in air are done. The absorbed solar energy of high efficiency heat evaporator is 25%-35% higher than that of conventional air source heat pump solar collector/evaporator, and also higher than plat model by 7.3%.Secondly, the effect of high efficiency heat collector's structure on air flow is simulated by FLUENT. Through adjustment of structure parameters such as fin's shape,angle,spacing and so on, the air is in touch with absorber plate sufficiently and the air flow is promoted, flow resistance is reduced at the same time. Convective heat exchange is enhanced and absorption of solar energy is increased. The optimal structure parameters of heat collector are obtained by comparing with heat collector's income ratio of heat. And the integral optimization design method is formed.Based on theoretical research, prototype has been made at the end and tested under different weather conditions such as sunny days,cloudy days,nights. Experimental results show that the high efficiency heat pump hot water system integrated by tow sources can not only absorb solar energy efficiently, but also can absorb air energy efficiently which has a good thermal performance. The COP is about 2.7-5.0 under different weather conditions which is better than conventional air sourced heat pump system which is about 2.7-4.5.