| 摘要: |
| 喷射器作为热驱动喷射式制冷系统的核心部件，其性能会影响整个制冷系统的运行效率。极限工况是指喷射器从可以工作状态到不能工作状态的极端工况，对该工况下喷射器的特性研究具有重要意义。本文自行设计并搭建了以R134a为制冷剂的喷射式制冷系统极限工况的实验装置，分别对引射流体质量流量为零的极限工况下不同喷射器工作流体压力及喷射器出口背压对缩放喷嘴出口背压的影响规律进行了实验研究。结果表明：极限工况下，喷嘴出口背压同时受工作流体压力和喷射器出口背压的影响，随工作流体压力升高而降低，随喷射器出口背压升高而升高。同时，得到该喷射器在工作流体压力为1.5~3.2 MPa，且喷射器出口背压在0.66~0.96 MPa范围内的最低引射流体压力，为工程应用提供参考。 |
| 关键词: 制冷系统 喷射器 实验工况 R134a |
| DOI： |
| 投稿时间：2016-12-31
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| 基金项目:上海高校青年教师培养资助计划(10-16-301-801)资助。 |
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| Experimental Study on Ejector Performance under Limiting Operating Condition |
|
Dai Zhengshu1, Chen Guangming2, Zhang Hua1, Lü Wandou1, Xu Qing1
|
| (1.School of Energy and Power Engineering, University of Shanghai for Science and Technology;2.Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province, Institute of Refrigeration and Cryogenics, Zhejiang University) |
| Abstract: |
| The ejector is the key component in a heat-driven ejector refrigeration system, and its performance is of considerable importance to the system efficiency. The limiting operating condition is defined as the working condition when the secondary mass flow rate is equivalent to zero, and the performance under this working condition is important to the ejector working mechanism and application. In this study, experimental apparatus to study the ejector performance under the limiting operating condition was designed and constructed, using R134a as a refrigerant. The effects of the primary flow pressure and ejector back pressure on the back pressure of the converging-diverging nozzle were studied experimentally under the limiting operating condition, i.e., when the secondary mass flow rate was zero. The experimental results show that both the primary flow pressure and ejector back pressure have considerable influence on the back pressure of the nozzle under the limiting operating condition. The nozzle back pressure decreases with an increase in the primary flow pressure, but increases with an increase in the ejector back pressure. In this study, detailed values were obtained for the lowest evaporating pressure of the system. The findings indicate that the primary flow pressure is in the range of 1.5-3.2 MPa and the ejector back pressure is in the range of 0.66-0.96 MPa. These results can provide guidance for ejector refrigeration system application. |
| Key words: refrigeration system ejector test condition R134a |
