| 摘要: |
| 为实现微小空间高效散热,本文以去离子水为工质，实验研究了工质流经高度和直径均为500 μm的微圆柱组成的叉排微柱群通道时的饱和沸腾换热特性，并采用高速摄像机记录了通道内不同加热功率的气液两相流型，实验参数设定质量流速为341~598.3 kg/(m2?s)，热流密度为20~160 W/cm2，蒸气干度为0~0.2。结果表明：随着热流密度增大，局部沸腾换热表面传热系数近似单调递减。在低干度区，局部沸腾换热表面传热系数随着质量流速的增加而增大，随着蒸气干度的增加而减小；受过冷沸腾气泡影响，工质进口温度越低，局部沸腾换热表面传热系数越大；随着热流密度增大，微柱群通道流动沸腾气泡流型依次为：泡状流、环状流，且泡状流区的局部沸腾换热表面传热系数明显高于环状流区。 |
| 关键词: 微通道 饱和沸腾 两相流 可视化 沸腾换热表面传热系数 |
| DOI： |
| Received:August 25, 2017 |
| 基金项目:山东省自然科学基金(ZR2016YL005)和山东省科学院基础研究基金（科基合字（2015）第8号）项目资助。 |
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| Experimental Study of Saturated Flow Boiling Heat Transfer in an Array of Micro-pin-fins |
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| Abstract: |
| Experiments were carried out to investigate the saturated flow boiling heat transfer and visualize the two-phase flow patterns for deionized water in a micro-pin-fin heat sink with cylindrical fins with a height of 500 μm and diameter of 500 μm. The test parameters were as follows: a mass flow rate G = 341–598.3 kg/(m2?s), heat flux q = 20–160 W/cm2, and steam dryness X = 0–0.2. The results show that the local boiling surface heat transfer coefficient decreases monotonously with an increase in heat flux. The heat transfer coefficient of the local boiling surface increases with the increase in the mass flow rate, and decreases with an increase in steam dryness within a low dryness region. With the influence of sub-cooled boiling bubbles, the lower the working fluid inlet temperature, the greater the local boiling surface heat transfer coefficient. The flow pattern of bubbling in the micro-channels shows a bubbly flow and an annular flow with an increase in the heat flux density. The local boiling surface heat transfer coefficient of a bubbly flow is significantly higher than that of an annular flow. |
| Key words: micro-pin fins saturate flow boiling two-phase flow visualization boiling surface heat transfer coefficient |
