| 摘要: |
| 两级蒸发引射制冷循环中通过二级蒸发器不仅能调节引射器出口干度还能提高系统效率。通过改变第二蒸发器冷冻水流量对两级蒸发引射制冷系统进行实验研究，并与改变引射器面积比的调控效果进行比较。结果表明：在实验工况范围内，气冷器压力、第一蒸发器压力和压缩机流量都随第二蒸发器冷冻水流量的增加而增大；而且引射器面积比越大，气冷器压力越高而蒸发器压力和压缩机流量越低。同时，系统引射系数随第二蒸发器冷冻水流量的增加而降低，而制冷量和COP则升高，尤其是在小引射系数下，系统制冷量和COP提高的更为明显。本研究为引射循环提供了另外一种良好的调控思路。 |
| 关键词: 引射制冷系统 两级蒸发 系统性能 二氧化碳 |
| DOI： |
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| 基金项目:国家自然科学基金 (51076120) 资助项目。 |
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| Experimental Investigation on the Effect of the Second Stage Evaporation on the Transcritical CO2 Ejector Expansion Refrigeration System |
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Zheng Lixing1, Deng Jianqiang1, He Yang2
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| (1.School of Chemical Engineering and Technology, Xi'an Jiaotong University;2.State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University) |
| Abstract: |
| An ejector expansion refrigeration cycle with two stage evaporation can not only regulate the exit quality of ejector but also improve the coefficient of performance of system. This experimental study presents the effect of the second stage evaporator on the transcritical CO2 ejector expansion refrigeration system with two stage evaporation. The system performances were investigated with the variation of chilled water flow rate of the second stage evaporator, and the effects were compared with that by the regulation of ejector area ratio, which is the mixing section area to nozzle throat area. The experiment results indicate that the pressure of gas cooler and the first evaporator as well as the compressor mass flow rate increase with the rise of the chilled water flow rate of the second stage evaporator. The larger the ejector area ratio, the higher the gas cooler pressure and the lower the first evaporator pressure and compressor mass flow rate. Furthermore, the entrainment ratio decreases with the increase of chilled water flow rate of the second stage evaporator, while the COP and cooling capacity of the system increase. Especially, the COP and cooling capacity increase largely at lower entrainment ratio. This study provides another excellent regulation approach for ejector expansion cycle. |
| Key words: ejector expansion refrigeration system two-stage evaporation performance of system carbon dioxide |
