| 摘要: |
| 为改善变工况条件下，定频双级压缩制冷系统不能达到最佳状态运行的现状，本文搭建变流量双级压缩制冷系统实验台，分析了变工况条件下，调节高压级压缩机频率来改变低高压级压缩机输气量之比，对一次节流中间不完全冷却造成的影响。结果表明：当冷凝温度为30 ℃，蒸发温度为?35~?20 ℃，低高压级压缩机输气量之比由1.25增至3.33时，系统制冷量随着低高压级压缩机输气量之比的增加逐渐减少，性能系数COP最大为2.37；当蒸发温度从?20 ℃降至?35 ℃，每降低5 ℃，最佳COP下的低高压压缩机输气量之比依次增大22.10%、12.52%、14.29%。故实际系统设计时，可参考实验数据，根据不同蒸发温度和制冷量需求，调节合适的低高压级压缩机输气量之比，使系统运行达到最佳状态。 |
| 关键词: 双级压缩 变流量 输气量 COP |
| DOI： |
| 投稿时间：2018-09-06 修订日期：2018-11-25
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| 基金项目:国家科技支撑计划（2014BAK17B02）和国家自然科学基金(11572223)资助项目。 |
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| Experimental Study on Variable-Flow Two-Stage Compression Refrigeration System |
| Yang Yongan,Jiang Chunyan,Wu Chuanzhi,Luo Jiancheng |
| (Tianjin University of Commerce, Refrigeration Engineering Research Center of Ministry of Education, Tianjin Refrigeration Engineering Technology Center) |
| Abstract: |
| The constant-frequency double-stage compression refrigeration system fails to run in the best state at the working or load changing conditions. To improve its performance, maintain the maximum performance coefficient, and achieve rapid and accurate cooling, a variable-flow double-stage compression experimental bench was set up. The proposed method was able to control the refrigerant gas flow rate of the low-pressure compressor and change the refrigerant mass flow rate. Therefore, the experimental study of two-stage compression cooling was conducted. Results showed that the refrigeration capacity of the system decreased with an increase in the ratio of input gas of low- and high-pressure compressors (in the range of 1.25 to 3.33) at the condensation temperature of 30 ℃, evaporation temperature of ?35–?20 ℃. The cooling capacity of the system gradually decreased with the increase of the ratio of input gas of low- and high-pressure compressors and the maximum coefficient of performance (COP) is2.37. The ratio of input gas of low- and high-pressure compressor under the optimum COP increased with the decrease of evaporation temperature. Considerably, as the evaporation temperature decreased by 5 ℃ when the evaporation temperature was in ?35–?20 ℃, the ratio of the inputgas of the low- and high-pressure compressors under the optimal COP increased by 22.10%, 12.52%, and 14.29%, respectively. Therefore, for the actual system design, the experimental data can be used to adjust the ratio of input gas of low- and high-pressure compressors according to the different evaporation temperatures and refrigeration demands. |
| Key words: two-stage compression variable flow ratio of input gas COP |
