人工冰场用跨临界CO_(2)并联压缩制冷试验研究

Experimental research on performance of transcritical CO_(2)parallel compression refrigeration system applied to artificial ice rink

为了研究应用于人工冰场的跨临界CO_(2)并联压缩制冷系统性能,搭建了跨临界CO_(2)并联压缩制冷系统,试验研究了单压缩机独立运行以及双压缩机并联运行时,蒸发温度与压缩机运行频率对系统COP、制冷量、压缩机功率、制冷剂流量、压比的影响。结果表明,随蒸发温度升高,COP、制冷量、压缩机功率和制冷剂流量均增大,压比减小,蒸发温度为-9.4℃时,COP达到本试验的最大值2.00;在试验工况40~60 Hz范围内,随着压缩机运行频率增加,制冷量、压缩机功率、制冷剂流量和压比均增大;单台压缩机独立运行和并联压缩时,COP均在50 Hz达到最大,且并联压缩COP随压缩机运行频率差的增加而降低,最大可相差26.67%。建立了系统COP预测模型,通过蒸发温度与排气压力对COP进行预测,并与并联压缩试验结果进行了对比,所构建模型预测结果与同频率并联压缩系统试验测得COP平均误差为3.7%。研究结果可为并联压缩制冷系统设计提供借鉴和指导。

In order to explore the performance of transcritical CO_(2)parallel compression refrigeration applied to artificial ice rink,a transcritical CO_(2)parallel compression refrigeration system was established.Effects of evaporation temperature and compressor frequency on COP,cooling capacity,compressor power consumption,refrigerant flow rate and compression ratio were analyzed when single compressor runs independently and two compressors runs in parallel.The results indicate that COP,cooling capacity,compressor power consumption and refrigerant flow increase with the increase of evaporation temperature,and the compression ratio decreases.When the evaporation temperature is-9.4℃,COP reaches the maximum value of 2.00 for this test.In the range of 40~60 Hz test condition,with the increase of compressor frequency,the cooling capacity,compressor power consumption,refrigerant flow rate and compression ratio all increase.When a single compressor runs independently or the parallel compressors run at the same time,the COP reaches the maximum value at 50 Hz.At the same time,COP decreases with the increase of compressor operating frequency difference,and the COP difference can reach max.26.67%.A prediction model for the system was established to predict COP by evaporation temperature and discharge pressure.The predicted results were compared with the test results of the parallel compressors.The average error between the results predicted by the built model and the COP measured in the 17 parallel compressor system test at the same frequency is 3.7%.The research results provide reference and guidance for the design of parallel compression refrigeration system.