Theoretical And Experimental Research On Air-cooled Heat Pump System With Total Condensing Heat Recovery

Energy utilization and environmental protection are two major themes in today’s world,and are also two major factors restricting the development of national economy.In order to improve the thermal pollution of air conditioning in summer,and develop the use of air-conditioning and hot water system efficiency,the paper points out the significance of total heat recovery air source heat pump system and present the current situation of research.After introducting the development and technology evolution of heat recovery technology,the article analysises the influence on heat recovery system performance about the condensation temperature,heat exchanger,water temperature etc,pointing out the high condensation temperature and water temperature have bad effects on the system.Based on calculation and selection of design and the theory of heat recovery system,it develops a test machine,from the analysis of the experimental data and the change of the comparative study of the nominal model,nominal water heating mode and the nominal total heat recovery mode,the main conclusions are:(1) In the same experimental conditions,the prototype to total heat recovery mode and the nominal model compared to the refrigerating capacity of the smaller;when the environment temperature is 20 degrees,20 degrees hot water from the heating to 55 degrees,total heat recovery mode,system average heat is 37.35 kW,lower than the nominal system hot water and total heat recovery system heat theory design.The actual input power of total heat recovery mode is about 9.54 kW,compared with the system nominal cooling mode or nominal water heating mode,the input power is smaller.(2) In the name of the cooling model, prototype theory is 3.21,the measured value is 2.91,slightly smaller than the theoretical calculation.The name of heating mode, heating condition theory design is 4.54,and transient heating coefficient of working prototype design is 4.06,smaller than the theoretical value.The average heating coefficient test is 3.85,also smaller than the theoretical value.In the design heat recovery mode,the environment side temperature is 20 degrees centigrade,andthe air inlet temperature keeps 12 degrees,then the hot side water temperature varys from 20 degrees to 55 degrees in the heating system.The testing process of average refrigeration coefficient is 3.09,higher than the single prototype model of the refrigeration coefficient.When the hot water temperature reached 45 degrees,the refrigeration coefficient is 2.73,lower than that of the cooling mode.The average heating coefficient model system of total heat recovery is 4.1,lower than the average heating coefficient of water heating mode, but the whole system of total heat recovery unit mode energy efficiency ratio is from 4.87 to 9.63,higher than that of the single cooling or hot water saving effect.(3) When the inlet water of the test conditions of total heat recovery mode in air conditioning is set to 12 degrees,and hot water outlet temperature increase from 20 degrees to 55 degrees,the measurement of heat and standard refrigeration ratio is between 1.12~1.27,and average of 1.23.With the water temperature increasing, the ratio increases gradually,but remained at 1.1~1.3.