吸气喷液对涡旋压缩机及系统性能的影响

Research on Performance of Scroll Compressor and System under Suction Injection

为了研究吸气喷液冷却对涡旋压缩机及制冷系统性能的影响,本文搭建了吸气喷液回路实验台,并建立了含有泄漏和换热损失的数学模型。研究了不同喷液流量和不同压比下,压缩机排气温度和系统制冷量以及COP的变化情况。数值计算结果和实验结果吻合程度较高,在低喷液量下,误差在2.5%左右;在高喷液量下,误差在10%左右。结果显示:排气温度随喷液量增大而降低,COP随喷液量有微小提升后降低。喷液量较小时,可使排气温度降低14℃,而系统COP微小提升0.6%;喷液使得排气温度降低42℃时,可保证系统COP降低小于5%;高压比下,吸气喷液系统COP存在最佳值,且压比越高COP降低幅度越小,吸气喷液可以有效的用于降低压缩机排气温度。

In order to analyze the relationship between the suction injection and the performance of the scroll compressor, the suction injection circuit was set up. And the mathematic model, containing the loss of leakage and heat exchange, was established at the same time. The discharge temperature and the refrigerating capacity and the COP of the system were investigated when the injection flow rate and the pressure ratio were varied. The result of the simulation was in reasonable agreement with the experimental data. The error was 2.5% at the low injection flow, and 10% at the high flow. It was also found that the discharge temperature decreased and the COP slightly in- creased then went down, when the injection flow increased. The COP of the system increased by 0.6% , while the discharge temperature decreased by 14 ℃ at the condition of the low injection flow. When the discharge temperature decreased by 42 ℃, the decline in the COP was less than 5%. Additionally, there existed an optimal value of the COP in the suction injection circuit when the injection flow varied at the high pressure ratio. Furthermore, the higher the pressure ratio was, the lower the COP decreased. As a result, the suction injection could put into use to decrease the discharge temperature.