| 摘要: |
| 微通道平行流换热器内制冷剂分配不均是限制其进一步推广应用的原因之一，当微通道平行流换热器做蒸发器时，制冷剂在换热器入口为气液两相状态，会加剧其分布不均匀性。本文以气液两相R134a制冷剂为工质，提出一种数值仿真模型，并利用前人实验数据验证了模型可靠性。提出通过改变不同扁管在集管内突出深度以改善制冷剂分配特性的4种方案，利用数值仿真模型进行计算，当质量流速为100 kg/(m2?s)，制冷剂干度为0.4时，发现通过改变不同扁管在集管内的突出深度可以使液相制冷剂分配特性改善29.4%~52.4%。 |
| 关键词: 微通道换热器 数值仿真 扁管突出深度 流体分配 均匀性 |
| DOI： |
| 投稿时间：2021-02-20 修订日期：2021-05-23
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| 基金项目: |
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| Distribution Characteristics and Optimization on Parallel Flow Microchannel Heat Exchanger |
| Du Lin,Zhou Liyang,Chen Qi,Wang Shuhua,Wang Binhui,Gao Ruqi,Chen Guangming,Tang Liming |
| (College of Energy Engineering, Zhejiang University;JUHUA Group Corporation) |
| Abstract: |
| The uneven distribution of refrigerants in parallel flow microchannel heat exchangers is one of the reasons that limit their further promotion and application. When the parallel flow microchannel heat exchanger is used as an evaporator, the refrigerant at the inlet of the evaporator is in a vapor-liquid two-phase state, which causes an uneven distribution of vapor and liquid refrigerant in the evaporator. In this study, a two-phase R134a refrigerant was used as the working fluid, and a numerical simulation model which was verified by previous experimental data was proposed. Four schemes to improve the refrigerant distribution characteristics by changing the protrusion depth of different flat tubes are proposed. Numerical simulation models were used for the calculation. When the mass flow rate is 100 kg/(m2?s) and the refrigerant quality is 0.4, it is found by changing the protrusion depth of different flat tubes in the header, the liquid phase refrigerant distribution characteristics can be improved by 29.4%–52.4%. |
| Key words: microchannel heat exchanger numerical simulation flat tube protrusion depth fluid distribution uniformity |
