Experimental Research On R32/R600a Used In Circulating Heating Type Heat Pump Water Heater

At present, the refrigerants which are widely used in the air conditioning industry are usually CFCs and HCFCs.These refrigerants do not meet the requirements on environmental protection.It is difficult to pure refrigerant that meeting the requirements of environmental protection, safety and thermodynamic properties at the same time.But mixture refrigerant is possible to achieve that.So research on mixture refrigerant is a very important direction of finding a substitute for R22.The two components R32 and R600 a,which are involved in this project, have good The performance of environment and safety,so mixture refrigerant of R32/R600 a has a very good value for research.And this thesis focuses on the following elements:(1)Researching on mixture refrigerant R32/R600 a in theory from the performance of environmental protection 、 safety and thermodynamics. conclusion is that:mixture refrigerant R32/R600 a can meeting the requirements of environmental protection.And,with the increase of R32 concentration,the explosion limit of the mixture will be increased.So the safety performance of the mixture refrigerant is better than that of the pure refrigerant R600 a.So R32/R600 a mixtures is expected to be a new alternative refrigerant with excellent comprehensive performance.(2)Calculating of the performance of the theoretical cycle and the conclusion is that:with the range of R32 mass ratio of 0-70%,the condensation pressure of the system is less than 2.5 MPa and Compression ratio is appropriate.Exhaust temperature is lower than R22 system.The heat quantity per unit volume, heat per unit mass, and the coefficient of thermal performance of the system are all higher than that ofthe R22 system.(3)Experimental research on R22 and R32/R600 a used in circulating heating type heat pump water heater.And the conclusion is that:With the increase of R32 component,there is a tendency on the cycle performance of the system of mixture refrigerant R32/R600 a to rise first and then fall.Ans the addition of R32 is beneficial to improve the cycle performance of the system of R600 a.But the overall thermal performance is lower than that of the R22 system.The reason for this situation is that the system components are not matched with the mixture refrigerant R32/R600 a.With the increase of R32 component,the length of heating time of the system showed a decreasing trend.And the minimum length of the heating time is less than that of the R22 system,which shows that the heating capacity of system of mixture refrigerant R32/R600 a is improved than that of the R22 system.