| 摘要: |
| 非共沸混合工质冷凝是温度不断降低的等压冷凝过程，气相和液相组分不断变化。当冷凝器出口温度为300 K时，液相混合工质R600a/R23/R14的质量分数为78.04/12.62/9.34，冷凝液大部分为R600a，但含有相当数量的中低沸点工质。冷凝温度降低至280 K时，R600a在气相中的比例为9.8%，即使冷凝温度降低到质量分数35/35/30的泡点温度249.49K，R600a在气相的质量分数仍然占2.67%。相分离器I能够分离78.04%的高沸点工质R600a，但低沸点工质R14在液相中占9.34%。相分离器II只能分离30.27%的R23，12.62%依靠相分离器I分离，其余的R23都被带入到蒸发器。R600a在蒸发器内仍然有6.31%的含量，低沸点工质R14在蒸发器内占45.64%。 |
| 关键词: 自动复叠制冷 R600a/R23/R14 组分变化特性 非共沸混合工质 |
| DOI： |
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| 基金项目:国家自然科学基金 (51176124) 资助项目。 |
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| Composition Change Characteristics of Non-azeotropic Mixturesof Auto- cascade Refrigeration System |
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Rui Shengjun1, Zhang Hua2, He Tao1, Luo Hao1
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| (1.Vehicle & Transportation Engineering Institute, Henan University of Science and Technology;2.Institute of Refrigeration Technology, Shanghai University of Science and Technology) |
| Abstract: |
| The condensation process of non-azeotropic mixed refrigerant is a isobaric process. Meanwhile, the concentrations of vapor and liquid continuously change. When the outlet temperature of condenser is 300 K, the mass fraction of R600a/R23/R14 in liquid phase mixture is 78.04/12.62/9.34, respectively. The R600a is the dominant component in the liquid mixtures. However, it also contained considerable amounts of middle and low boiling refrigerants. When the condensing temperature is reduced to 280 K, the mass fraction of R600a in vapor is 9.8%. Even if the condensing temperature is decreased to 249.49 K (the bubble point temperature of 35%R600a/35%R23/30%R14), the mass fraction of R600a in vapor phase still reaches 2.67%. The vapor-liquid equilibrium gravity separation method couldn’t separate mixed refrigerants completely. The separation ratio of R23 by phase separator I and phase separator II are 12.62% and 30.27%, respectively. The rest of the R23 goes into the evaporator. Phase separator I could separate 78.04% of the refrigerant R600a with high boiling point temperature. There are 9.34% R14 (low boiling refrigerant) in liquid phase. The mass fraction of R600a in evaporator still reaches 6.31%, the low boiling refrigerant R14 accounts for 45.64%. |
| Key words: auto-cascade refrigeration system R600a/R23/R14 composition change characteristics non-azeotropic mixtures |
