Abstract:

The refrigerant charging quantity has significant effect on the performance of a refrigeration system. For a specific mixed refrigerant (MR) Joule-Thomson cooler, proper MR charging quantity is determined by operation pressure, temperature and concentration of components. It is difficult to determine the optimal MR charging quantity by means of experimental test, so a MR mass charge prediction model is established in this paper. Using the integral method, the Linde-Hampson cooler is divided into four parts to calculate the MR mass distribution and the liquid hold-up. The calculation result shows that, over 60% of the MR is accumulated in the hot steam of the recuperative heat exchanger, the liquid MR occupies more than 80% of the total charging quantity, and the mass of liquid MR will increase as the refrigerating temperature decreases. An experimental investigation is used to verify the accuracy of this model. The result shows that, in the refrigeration temperature of -100-60℃, the deviation between the calculated MR charging quantity and actual one is not more than 20%. The deviation between the calculated proportion of components and the experimental result is also less than 20%.

Key words: non-azeotropic mixture, optimization, computer simulation, experimental validation, refrigerant mass charge

摘要：

制冷剂充灌量对制冷系统性能有着重要的影响。对于一个确定的混合工质节流制冷系统,其合适的制冷剂充灌量由压力、温度以及混合工质组分等多种因素决定,通过实验方法确定适合的制冷剂充灌量十分困难。因此本文将Linde-Hampson制冷系统分为4个部分,基于分布参数积分方法,建立混合工质充灌量预测模型,求出了各组分制冷剂在系统中的质量分布和液相积存量,并进行实验分析。计算结果表明,在实验范围内,实验系统的回热器热通道中制冷剂质量最多,占总充灌量的60%以上;液相制冷剂占80%以上,且随制冷温度降低,液相制冷剂质量增加。通过对比实验结果,计算模型在制冷温度为-100～-60℃的工况中,充灌量及各组分比例的计算值与实验值的偏差误差均不超过20%。

关键词: 非共沸混合物, 优化, 计算机模拟, 实验验证, 制冷剂充灌量