喷射式制冷系统中制冷剂R141b替代工质的研究

Study on Substitution of Refrigerant R141b in Jet-type Refrigeration System

为研究喷射式制冷系统中制冷剂R141b的替代工质,本文以太阳能喷射式制冷系统为研究对象,选取R134a、R152a、R142b、R718、R245fa、R141b和R236fa等7种制冷剂进行物理性质的比较,发现制冷剂R245fa与R141b的物性较为接近,故采用制冷剂R141b和R245fa分别对该系统进行建模计算。结果表明,制冷剂R245fa与R141b在低蒸发温度或高冷凝温度下差距最小:喷射系数相差在1%以下,系统性能系数(COP)相差在4%以下;且喷射系数与蒸发温度成正比,与冷凝温度成反比;COP与蒸发温度成正比,与冷凝温度成反比。采用R245fa为制冷剂,在发生温度为100℃时,系统COP最大可达到0.5左右。

In order to study the alternative working fluid of refrigerant R141b in the jet-type refrigeration system, in this paper, the solar-jet refrigeration system is taken as the research object. Seven refrigerants including R134a, R152a, R142b, R718, R245fa, R141b and R236fa are selected for the comparison of physical properties. It is found that the refrigerant R245fa and R141b are similar in physical properties, so the system is modeled and calculated respectively by using the refrigerant R141b and R245fa. The results show that the difference of performance between refrigerant R245fa and R141b is minimal at low evaporation temperature or high condensation temperature;the injection coefficient differs by less than 1%, and the coefficient of performance (COP) differs below 4%;the injection coefficient is directly proportional to the evaporation temperature and is inversely proportional to the condensation temperature. The COP is proportional to evaporation temperature and inversely proportional to condensation temperature. When the temperature is 100 ℃, the COP of system using R245fa as refrigerant can reach about 0.5.