| 摘要: |
| 为研究喷雾冷却对空气侧传热压降性能的影响以及探寻喷雾恰好在微通道换热器表面完全蒸发的具体情况，本文搭建了一套带喷雾冷却的车用风冷型微通道换热器实验台，分析了空气侧在无喷雾状态和带喷雾状态下的传热压降特性。结果表明，无喷雾状态下实验得到的j因子和f因子与经典Chang关联式计算值有较好的吻合度，误差在±10%以内。带喷雾状态下j因子具有明显的提升，但提升效果随喷雾流量的减小和热壁面温度的降低而减弱，总体而言，f因子并未有明显的变化。喷雾流量临界值（恰好完全蒸发）与热壁面温度和风速呈正线性关系，其关联式可拟合得到。以Chang关联式为基础，喷雾状态下的j因子可通过相应的修正因子拟合得到，为喷雾状态下空气侧换热性能的预测提供依据。 |
| 关键词: 车用空调 微通道换热器 喷雾冷却 j因子 f因子 |
| DOI： |
| Received:October 09, 2022Revised:March 06, 2023 |
| 基金项目:国家重点研发计划（2020YFA0711500） |
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| Experimental Investigation on Heat Transfer Performance of a Compact Heat Exchanger with Spray Cooling |
|
Song Xia1, Wang Jiawei2, Shi Junye1, Chen Jiangping1
|
| (1.Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University;2.College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics) |
| Abstract: |
| To investigate the effects of spray cooling on air-side heat transfer and pressure drop, and to determine the water spray flow rate when spray droplets evaporate completely on the hot surface of a compact heat exchanger, we built an experimental plant to analyze the air-side heat transfer and pressure drop of an automotive compact heat exchanger with and without spray cooling. The results indicate that the j factor and f factor obtained from experiments without spray were in good agreement with those calculated from Chang’s correlations, within an error of 10%. Compared with that without spray, the j factor with spray increased significantly, but the increasing rate declined with a decrease in the spray flow rate and substrate temperature. The f factor with spray changed slightly compared with that without spray. Using the substrate temperature and air velocity as variables, we proposed a correlation of the critical value of the spray flow rate (where spray droplets can evaporate completely). Based on Chang’s correlation, the j factor with spray can be obtained using a correction factor. These results support the prediction of air-side heat transfer with spray and also facilitate future application of spray cooling in automotive air conditioners. |
| Key words: automotive air conditioner compact heat exchanger spay cooling j factor f factor |
