喷釉干燥用空气源热泵复叠式循环系统COP影响因素分析

Influence Factors on COP of Air Source Heat Pump Cascade CirculationSystem for Spray Glaze Drying

在国家“双碳”目标的引领下,自然工质二氧化碳空气源热泵在清洁能源领域越来越受重视。建立了R134a/CO_(2)复叠式热泵系统热力模型,基于REFPROP软件得到循环工质的热物理参数,利用MATLAB软件编程分析环境温度、供热温度、低温蒸发温度、中间冷凝温度、高温冷凝温度、中间换热温差等因素对热泵系统的COP(性能系数)的影响。研究结果表明,在70℃的供热温度下复叠式热泵系统的COP比常规热泵系统高52.53%。复叠式循环系统低温级在给定蒸发温度工况下,具有与之相匹配的最佳中间冷凝温度。当中间冷凝温度为25℃时,最大COP为4.68。高温冷凝温度50℃和70℃系统的COP分别为3.92和2.93。

Under the guidance of the country’s“double carbon”goals,carbon dioxide air source heat pumps with natural working medium are receiving more and more attention in the field of clean energy.A thermodynamic model of R134a/CO2 cascade heat pump system was proposed.The thermophysical parameters of working fluid are obtained by using the REFPROP software.The effects of environmental temperature,water supply temperature,low-temperature evaporation temperature,intermediate condensation temperature,high-temperature condensation temperature and intermediate heat transfer temperature difference on COP of the heat pump system are analyzed by using MATLAB software programming.The results indicate that COP of the cascade heat pump system is 52.53%higher than that of conventional heat pump system at heating temperature of 70℃.The low temperature stage of the cascade cycle system has matching optimum intermediate condensation temperature under the given evaporation temperature condition.When the intermediate condensation temperature is 25℃,the maximum COP is 4.68.The COP values of the system with high-temperature condensation temperatures of 50℃and 70℃are 3.92 and 2.93,respectively.