Theoretical Analysis And Experimental Research On R1234yf Heat Pump System

As a new environmentally friendly olefin refrigerant,R1234 yf with its excellent performance,ODP is zero and GWP is very low,which attracts much attention in the field of refrigerant replacement.Based on existing R134 a heat pump test bench,the R1234 yf heat pump test bench was designed and set up,Experimental test results were studied for future development of high efficient heat pump products to provide materials.R1234yf is chosen as working fluid of heat pump system,and its performance is research objective.Compared with R134 a system,theoretical analysis and experimental research are adopted.Based on the first law and the second law of thermodynamics,the mathematical models of heat pump systems with two kinds of refrigerants R134 a and R1234 yf are set up respectively,and the effect of evaporation temperature,condensation temperature,superheat and supercooling on performance are analyzed.The theoretical analysis shows that the COP and exergy efficiency increase with the increase of evaporation temperature,while the COP and exergy efficiency of R1234 yf system are 2.07%~3.01% and 0.53% ~ 0.64% lower than those of R134 a system,respectively.Inlet temperature of cooling water rises,system COP decrease,R1234 yf system is slightly lower than the R134 a system,but exhaust temperature increases;cooling water flow increases,system COP increases and discharge temperature decreases;inlet temperature of chilled water increase,system COP and discharge temperature increase;increasing flow of chilled water can increase system COP and discharge temperature.After theoretical and experimental research shows that although COP of R1234 yf system is slightly lower than that of R134 a system under the same conditions,environmental characteristics of R1234 yf are more obvious and discharge temperature is lower.As an alternative refrigerant for the R134 a,it still has certain potential for development.