摘要:
为了研究R22替代制冷剂R134A、R407C、R410A、R32、R290在热泵热水器中的热力学性能,设定冬季工况蒸发温度-10°C、冷凝温度65°C,夏季工况蒸发温度20°C、冷凝温度65°C,过冷度和过热度均为5°C.计算了不同工质系统在冬季和夏季工况的理论循环性能,对比分析了各系统的变工况特性.结果表明:R410A和R32的单位容积制热量较高,这有利于减小压缩机的功耗和体积;R290和R32的单位质量制热量较高,能够有效降低工质充注量,进而增加系统安全性.随着蒸发温度升高,各工质系统制热系数均不断增加;随着冷凝温度升高,各工质系统制热系数均不断降低;过热度变化对各工质系统制热系数影响很小,而过冷度增加可以提高各工质系统制热系数.对于6种工质热泵热水器系统,蒸发温度在冬季工况对R32系统制热系数影响最大,当蒸发温度由-14°C升至-6°C,R32系统制热系数提高21.8%,夏季工况蒸发温度对R22系统制热系数影响最大,当蒸发温度由16°C升至24°C,R22系统制热系数提高22.1%.对应于冬季工况和夏季工况,冷凝温度和过冷度变化对R410A系统制热系数影响最大.%In order to study the thermodynamic properties of the alternative refrigerant R134A,R407C,R410A,R32 and R290 of R22 in heat pump water heater,the evaporation temperature in winter condition is set to-10°C,the condensing temperature is set to 65 °C,and the evaporation temperature in the summer condition is set to 20 °C,the condensing temperature is set to 65 °C,and the degree of supercooling and superheat is both 5 °C.The theoretical cycle performance of different refrigerant is calculated in the winter and summer conditions,and the variable condition characteristics of the refrigerant in the heat pump system is compared and analyzed.The results show that it has a higher unit volume heat capacity for R410A and R32,which helps to reduce the power consumption and the volume of the compressor;it has a higher unit mass heat capacity for R290 and R32,which is good for reducing refrigerant charge and improving system security.With the increase of the evaporation temperature,the refrigerant performance coefficient increases;with the increase of the condensation temperature,the refrigerant performance coefficient decreases;the influence of the change of the degree of superheat on the performance coefficient of the refrigerant is not obvious,and an increase of the degree of supercooling can improve the performance coefficient for each of the refrigerant system.In these six kinds of refrigerant,the R32 system performance coefficient is influenced most obvious by the evaporation temperature in winter conditions,the COP increased by 21.8 %,and in summer conditions the R22 system coefficient of performance is influenced most significant with the increase of evaporation temperature,the COP increased by 22.1%;at the same time,in winter and summer conditions,the increase of condensing temperature and degree of supercooling has a greatest impact to the performance coefficient for R410A system.