R507A/R744载冷系统与乙二醇水溶液系统的能效对比

Comparison of Energy Efficiency Between R507A/R744 Secondary Refrigeration System and Ethylene Glycol Aqueous Solution System

乙二醇由于凝固点低、性质稳定、与水混溶、使用的温度范围广、价格便宜、热容量较大等优点被当做最常用的载冷剂之一。CO_(2)(R744)是一种天然环保载冷剂,GDP=0,GWP=1,易于获得,价格低廉,蒸发潜热较大,单位容积制冷量高,具有优良的流动、传热特性和良好的化学稳定性,并且具有良好的安全性、无毒、不可燃。其在载冷剂循环系统中是通过气液相变来实现热量的传递的。在传递相同冷量的前提下,其循环量远远小于其他液相载冷剂。载冷剂系统为无油运行,避免了冷冻油进入蒸发器造成换热效率降低。对比了R507A/R744载冷系统及乙二醇水溶液系统在高温库(0~8℃)工况下的能效,为该工况下载冷剂的选择提供了参考。

Ethylene glycol is regarded as one of the most commonly used secondary refrigerants because of its low freezing point,stable properties,miscible with water,wide temperature range,low price and large heat capacity.CO_(2)(R744)is a natural environment-friendly refrigerant,GDP=0,GWP=1,easy to obtain,low price,large latent heat of evaporation,high refrigerating capacity per unit volume,excellent flow and heat transfer characteristics,good chemical stability,good safety,non-toxic and non combustible.It realizes the heat transfer process through gas-liquid phase change in the refrigerant circulation system.On the premise of transferring the same cooling capacity,its circulation volume is far less than that of other liquid-phase secondary refrigerant.The secondary refrigeration system operates without oil,which avoids the reduction of heat exchange efficiency caused by refrigerant oil entering the evaporator.This paper compares the energy efficiency of R507A/R744 secondary refrigeration system and ethylene glycol aqueous solution system under the working condition of high temperature cold storage(0~8℃),which provides a reference for the selection of secondary refrigerant under this working condition.