基于高压级活塞排量的双级压缩制冷循环制冷量计算式

Formula for Refrigerating Capacity of Two-stage Compression Refrigeration Cycle Based on Piston Displacement of High Pressure Stage

为了研究双级压缩制冷循环制冷量简化计算方法,分析了高低压级压缩机活塞排量比、容积效率及指示效率等参数对制冷量的影响,以活塞排量比与中间温度的关系式为基础,作一定的简化处理,理论推导出基于高压级活塞排量的双级压缩制冷循环制冷量简化计算式,并通过实例进行了验证。实例计算结果表明:根据简化计算式以及常规方法计算的结果误差较小,吻合度高,推出的双级压缩制冷循环制冷量计算式是准确的。

The influences of ratio of piston displacement （RPD）, volumetric efficiency, and indicated efficiency of two- stage compressors on refrigerating capacity were analyzed to find a simplified method to calculate refrigerating capacity of a two- stage compression refrigeration cycle. By some simplifications and the relation of RPD and intermediate temperature, a simplified formula for refrigerating capacity of a two- stage compression refrigeration cycle was developed based on the piston displacement of high pressure stage. The present formula was verified with practical examples. The results show that the value of refrigerating capacity calculated with the present formula agrees well with that with the original method.