Abstract: In consideration of flash of water film, a model to predict the heat transfer in vacuum flash cooling was presented. The flash of water film was modeled based on the film penetration theory. The model was validated by the experimental results provided in this paper, and a favorable comparison was demonstrated with a deviation below 10%. Surface temperature and heat flux were obtained numerically and experimentally, and then analyzed. The heat transfer induced by flash of water film was dominant in high heat flux flash cooling. As spray flow rate increased, cooling performance was improved, but latent heat utilization decreased. The research result would lay theoretical foundation for application of vacuum flash cooling in the aerospace thermal control system.

Key words: heat transfer, numerical simulation, vaporization, flash evaporation, spray cooling

摘要： 通过对真空闪蒸冷却机理的分析，基于膜-渗透理论建立了以水为工质的真空闪蒸冷却换热模型，并利用实验研究和模型模拟相结合的方法，对闪蒸冷却的换热特性进行了研究。模型分析结果和实验结果误差小于10%，证明了所建模型的准确性。研究结果表明：液膜闪蒸换热在高热通量闪蒸冷却中占主导地位；随着工质流量的增加，闪蒸冷却换热性能提高；工质流量越小，液膜闪蒸换热所占份额越大，即工质闪蒸所带来的潜热利用率增加。研究结果为真空闪蒸冷却在航天热控方面的应用提供了理论基础。

关键词: 传热, 数值模拟, 汽化, 闪蒸, 喷雾冷却