用于低温复叠式制冷的CO2螺杆式压缩机组的性能实验

CO2在冷冻冷藏系统中适宜作为低温级制冷剂与其他制冷剂组成复叠式制冷循环。建立采用螺杆式压缩机组的NH3/CO2复叠式制冷实验系统,对低温级的CO2螺杆式压缩机组进行性能测试,并对主要技术参数进行分析,给出机组制冷量、轴功率、容积效率和绝热效率等在不同工况下的变化关系。在相同工况下CO2制冷机组的制冷量约是同型号氨机组的7.5～10.5倍,且在蒸发温度越低时差值越大。对NH3/CO2复叠式制冷机组和NH3单机双级压缩制冷机组的性能系数进行比较,前者在蒸发温度低于-40℃时性能系数更高。

Performance experiments of CO_2 screw compressor unit for low temperature cascade refrigeration

CO2 is appropriate for cascade refrigeration as the low-temperature stage refrigerant.Sets up an experimental NH3/CO2 cascade refrigeration system with screw compressors.Analyzes the main technical parameters of the CO2 screw compressor unit at low temperature stage and gives the variations of refrigerating capacity,shaft power,volumetric efficiency and adiabatic efficiency under different operating conditions.The refrigerating capacity of CO2 refrigeration unit is about 7.5 to 10.5 times as that of NH3 unit with the same model under the same conditions,and the ratio is greater with lower evaporation temperature.Compares the COP of NH3/CO2 refrigeration unit with that of NH3 two-stage refrigeration unit,and the former is higher when evaporation temperature is lower than-40 ℃.