R404A单机双级与R404A/R23复叠式制冷系统对比分析

摘要

通过建立双级压缩制冷系统和复叠式压缩制冷系统热力学模型,在冷凝温度40℃,蒸发温度为-65℃条件下,分析不同的中间温度对两种制冷系统压缩机轴功率,制冷剂流量以及制冷系数等性能参数的影响,并对两种制冷系统的实际运行费用进行了比较.结果表明:在相同的工况下,双级压缩式压缩机轴功率、R404A制冷剂质量流量低于复叠式;而双级压缩制冷系统COP(制冷性能系数)高于复叠式.在冷凝温度为40℃,蒸发温度为-65℃,中间温度为-14℃时,与复叠式制冷系统相比双级压缩式制冷系统全年运行节能可达13％.理论研究表明在-65℃的超低温工况下,双级压缩式制冷系统更具有优势.%Thermodynamic models of two-stage compression refrigeration system and R404A/R23 cascade refrigeration system were established.The effects of different intermediate temperatures on the compressor power,refrigerant flow rate and the energy coefficient of two kinds of refrigeration systems were analyzed and the operating costs of two kinds of refrigeration systems were compared at condensing temperature of 40 ℃ and evaporation temperature of-65 ℃.The results indicate that compared to cascade compression system,the compressor power and R404A refrigerant flow rate of two-stage compression system were lower and COP were higher.Two-stage compression refrigeration system energy would save up to 13％,at condensing temperature of 40 ℃,evaporation temperature of-65 ℃ and intermediate temperature of-14 ℃.The theoretical research showes that the performance of two-stage compression system was better in the ultralow temperature condition of-65 ℃.