基于R448A的高低温试验箱制冷系统特性实验研究

Research on Characteristics of Refrigeration System of High and Low Temperature Test Equipment Based on R448A

本文搭建了高低温试验箱实验台,研究了R404A有无回热循环的性能对比,在此基础上研究了新型制冷剂R448A制冷循环,并对比分析了充注量对蒸发温度、制冷量、COP等各项系统性能参数的变化特性。结果表明:在蒸发温度−25℃下,与无回热循环相比,带回热器的R404A制冷循环COP提高了25.19%;R448A循环比R404A循环的COP提高了3.72%。随着充注量的增加,蒸发温度逐渐增大,而制冷量和COP都呈现为先增大后减小的趋势。在充注量为240 g,环境温度为20℃时,R448A制冷系统与R404A制冷系统的制冷量差值最大,值为123.61 W。当环境温度从15℃升至25℃时,R448A制冷循环的COP降幅平均为11.96%,而R404A制冷循环的COP降幅平均为25.84%,表明R448A制冷系统的高温工况稳定性优于R404A制冷系统。

In this paper, a high and low temperature test equipment was built to study the performance comparison of R404A with or without a regenerative cycle. On this basis, the new refrigerant R448A refrigeration cycle was studied. The variation characteristics of the charge volume on the evaporating temperature, cooling capacity, COP and other system performance parameters are analyzed. The results show that at the evaporation temperature of −25˚C, the COP of the R404A refrigeration cycle with regenerator is increased by 25.19% compared with the cycle without re-generator;the COP of the R448A cycle is increased by 3.72% than that of the R404A cycle. With the increase of the charge, the evaporation temperature gradually increases, while the cooling capacity and COP showed a trend of first increasing and then decreasing. When the charge volume is 240 g and the ambient temperature is 20˚C, the difference in cooling capacity between the R448A refrigeration system and the R404A refrigeration system is the largest, with a value of 123.61 W. When the ambient temperature rises from 15˚C to 25˚C, the average drop in COP of the R448A re-frigeration cycle is 11.96%, and the average drop in COP of the R404A refrigeration cycle is 25.84%, indicating that the high temperature stability of the R448A refrigeration system is better than that of the R404A refrigeration system.