压缩机频率对双级压缩制冷系统的影响

为研究压缩机频率对双级压缩制冷系统性能的影响,通过实验,改变高温级压缩机频率来调节系统中间压力,分析一次节流中间不完全冷却双级压缩制冷系统性能的变化。研究表明,在冷凝温度30℃、蒸发温度-30～-40℃的工况下,固定低压级压缩机频率,当高压级压缩机频率一定时,系统COP随着蒸发温度的升高而升高;当蒸发温度一定时,高压级压缩机频率从45 Hz升高到75 Hz,系统中间压力小幅上升,压缩机功耗增加,制冷量增加,系统COP呈现先增大、后减小的变化趋势,故存在一个最优运行频率使系统运行达到最佳状态。

Effect of compressor frequency on two-stage compression refrigeration system

In order to study the influence of compressor frequency on the performance of two-stage compression refrigeration system, the intermediate pressure of the system was adjusted by changing the frequency of high temperature compressor through experiments, and the performance change of the two-stage compression refrigeration system with incomplete cooling in the middle of one throttle was analyzed. The results show that the frequency of low-pressure compressor is fixed at the condensation temperature of 30 ℃and the evaporation temperature of -30 to -40 ℃. When the frequency of high-pressure compressor is constant, the COP of system increases with the increase of evaporation temperature. When the evaporation temperature is constant ,the frequency of high-pressure compressor increases from 45 Hz to 75 Hz, the intermediate pressure of system increases slightly, the power consumption of compressor increases, and the refrigeration capacity increases. The COP of the system increases first and then decreases, so there exists an optimal operating frequency to make the system run in the best state.