| 摘要: |
| 搭建了一套封闭式喷雾冷却实验系统（水为工质），利用高速摄像仪对实验进行了可视化研究，分析对比了喷雾高度和喷雾压力在光滑表面及微结构表面对喷雾冷却换热特性的影响。结果发现：相比于光滑表面，在微结构表面上，喷雾高度和喷雾压力对喷雾冷却换热的影响更加明显。当喷雾高度较高时，降低喷雾高度可明显提高热流密度，直至喷雾高度较低且喷雾底圆与换热面内接时，继续降低喷雾高度，热流密度也略有上升；反之，提高喷雾高度则会降低热流密度，减小工质的有效流量，使换热表面过早出现干涸，表面温度均匀性变差。但大幅降低喷雾高度会延迟喷雾冷却进入两相区换热，降低喷雾冷却效率，并不利于换热。所以，喷雾高度对喷雾冷却换热特性的影响具有两面性，而喷雾压力的影响则趋于单一性，增大喷雾压力能提高喷雾冷却热流密度，增强表面温度均匀性，尤其在单相区，随着喷雾压力的增大，热流密度明显增大，最后趋近于一个固定值。 |
| 关键词: 喷雾冷却 喷雾高度 喷雾压力 CHF 温度均匀性 |
| DOI： |
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| 基金项目: |
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| The Influence of Spray Parameters on Heat Transfer Characteristics in Spray Cooling |
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Liu Ni, Li Lirong, Huang Qianwei, Zhong Zemin
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| (School of Energy and Power Engineering, University of Shanghai for Science and Technology) |
| Abstract: |
| Testing system is built up to study the heat transfer characteristics of micro-structure and smooth surface under the conditions of different spray height and spray pressure. The experiment is carried out in a closed loop spray cooling system with water as the working fluid with high speed camera. The experimental results indicate that both the spray height and spray pressure play more significant role in the spray cooling performance of the micro-structure surface than smooth surface. When the spray height staying in a high level, decreasing it until the critical height as indicated can obviously improve the heat flux, acquire higher CHF; Continually reducing the spray height can still slightly improve the heat flux, but a large margin reduction of the spray height can result in a decrease of heat flux and even delay the time of transition to two phase region. Thus the influence of spray height has two sides, different from the spray pressure, whose effect is monistic. Increasing the spray pressure can improve the heat flux and enhance the uniformity of the temperature distribution, especially in single phase region, and the heat flux increase obviously until to a stable value with the increasing of spray pressure. |
| Key words: spray cooling spray height spray pressure CHF temperature uniformity |
