Simulation Of R1234ze/152a In Evaporator Of Domestic Air Conditioner

R22,as the HCFCs refrigerant,is in the process of accelerating the elimination because of its ODP is not zero and GWP is high,but so far has not found a alternative refrigerant which all aspects of performance are suitable.In this paper,R152 a and R1234 ze were mixed at a mass ratio of 6: 4 into a new mixed refrigerant NCUR01.The simulation model of domestic air conditioner evaporator was established.The simulation program was developed by MATLAB,and the simulation program was used to study the performance of heat transfer and pressure drop of refrigerants NCUR01 and R22 in the evaporator of domestic air conditioner.In addition,the model of the air-conditioned room was established by using the FLUENT software,and the safety of the refrigerant NCUR01 in the room air conditioning indoor unit(the main component is the evaporator)was studied.The main research work is as follows:(1)The basic physical properties of the refrigerants NCUR01 and R22 in the range of 0~60? were calculated by the software REFPROP9.1,including saturated vapor pressure,latent heat of vaporization,thermal conductivity,specific heat at constant pressure,dynamic viscosity and density,and the parameters of the two refrigerants are compared and analyzed.The results show that the other physical properties of the refrigerant are more excellent than that of R22,except that the saturated liquid phase dynamic viscosity of NCUR01 is slightly larger than that of R22.(2)The cyclic performance of the theoretical cycles of the refrigerants NCUR01 and R22 were calculated and compared in the summer standard conditions and winter standard conditions.The results show that,both in the summer and winter standard conditions,the compressor unit input power of NCUR01 is larger than that of R22,but the unit cooling capacity of NCUR01 is larger than that of R22,so the COP of NCUR01 is larger than that of R22.In addition,the exhaust temperature of NCUR01 is much smaller than that of R22.Therefore,the circulation performance of therefrigerant NCUR01 is better than that of R22.(3)Calculated and compared the adaptability of refrigerant NCUR01 and R22 to evaporation temperature,condensation temperature,superheat and undercooling under theoretical circulation.The results show that the adaptability of refrigerant NCUR01 and R22 to the condensation temperature and the degree of subcooling in the cycle is not much different,and the adaptability of refrigerant NCUR01 to evaporative temperature and superheat is better than that of R22.(4)The mathematical model of the finned tube evaporator is established by using the steady-state distribution parameter method.The simulation algorithm of the model is designed and the model is developed into the household air conditioning evaporator simulation program by MATLAB.(5)The household air conditioning evaporator model established in this paper is validated by the experimental data of the evaporator performance of the refrigerant R22 in other literature.The results show that the deviation between the refrigerant outlet temperature and air outlet temperature by the simulation program and that obtained by the other literature is relatively large,and the deviation of the refrigerant outlet pressure and cooling capacity is relatively small,but the above deviations are within the allowable range.Therefore,it can be proved that the model is reliable.(6)The cooling capacity,pressure drop and evaporator air outlet temperature of the refrigerants NCUR01 and R22 under basic operating conditions and evaporator structure parameters were calculated by using the developed simulation program,and the simulation results of the two refrigerants were compared.The results show that the cooling capacity of NCUR01 is 15.7% higher than that of R22 and the pressure drop is 16.4% lower than that of R22,and the outlet temperature of evaporator is4.9% lower than that of R22.It is proved that the performance of NCUR01 in the household air conditioning evaporator is better than that of R22 in this condition.(7)The influence of the refrigerant inlet parameters,air inlet parameters and evaporator structure parameters on the simulation results of the refrigerant NCUR01 and R22 were studied by using the household air conditioning evaporator simulation program developed in this paper,and the simulation results of the two refrigerants were compared and analyzed.(8)The model of air conditioning room was established by using CFD technology,and the concentration distribution of NCUR01 in the room was studied when the refrigerator NCUR01 was leaked.The results show that the safety of NCUR01 in domestic air conditioners can be ensured by strict control of NCUR01 in the air conditioning system according to safety standards and safety measures in key areas.