| 摘要: |
| 非均匀润湿表面对流动沸腾过程中的流动模式和传热机制有重要影响。本文以去离子水为工质，实验研究了矩形微通道内硅表面和润湿异质性表面的过冷流动沸腾换热特性。通道横截面为0.5 mm×5 mm，过冷流动沸腾的质量通量分别为300、400 kg/(m2?s)，热流密度在30~300 kW/m2的范围内。实验在大气压下进行，过冷度为10 K。对比了与流动方向垂直（HC）和平行（HP）的疏水图案，讨论了不同热流密度、质量通量等工况下的硅表面和润湿异质性表面垂直向上流动沸腾，分析了不同工况下过冷沸腾的沸腾曲线、平均传热系数和两相流流型。结果表明：润湿异质性表面的流动沸腾换热表面传热系数最大提高了39.55%，换热机制主要为核态沸腾。 |
| 关键词: 流动沸腾 微通道 润湿异质性 流型 |
| DOI： |
| Received:January 05, 2023Revised:February 23, 2023 |
| 基金项目:国家自然科学基金(52076187)资助项目。 |
|
| Experimental Study of Subcooled Flow Boiling on Heterogeneous Wetting Surface |
|
Sun Jia, Lin Yuhao, Li Wei
|
| (Department of Energy Engineering, Zhejiang University) |
| Abstract: |
| With the recent increase in power density and miniaturization of various equipment, the requirements for compactness and efficiency of heat exchangers become increasingly stringent. Micro-structured surfaces have a significant impact on flow patterns and heat transfer mechanisms during flow boiling. To examine the effect of heterogeneous wetting surfaces on the flow boiling process, an experiment on subcooled vertical flow boiling on heterogeneous wetting surfaces in a narrow rectangular microchannel was conducted using a high-speed camera. Deionized water was used as the working fluid, and the cross-section of the channel was 0.5 mm × 5 mm. The mass fluxes of the subcooled flow boiling were 300 kg/(m2?s) and 400 kg/(m2?s). The heat flux was within 30–300 kW/m2. The experiment was conducted under atmospheric pressure, and the subcooling degree was 10 K. Hydrophobic patterns perpendicular (HC) and parallel (HP) to the flow direction were compared. The subcooled boiling curves, heat transfer coefficient, and pressure drop were investigated with respect to the variations in heat flux and mass flux, and their trends were analyzed along with the flow patterns. The heat transfer coefficient of flow boiling on heterogeneous wetting surface HC was enhanced by as much as 39.55% compared with a silicon surface with less pressure drop. During the boiling process, the dominant heat transfer mechanism was nucleate boiling, with numerous nucleation sites between the hydrophilic/hydrophobic stripes. |
| Key words: flow boiling microchannel heterogeneous wetting surface flow pattern |
