重力条件对喷雾冷却换热特性影响的研究

Effect Study of Gravity Condition on Heat Transfer Characteristics of Spray Cooling

喷雾冷却是一种高效的高热流密度散热方式,在空间热控领域具有重要的应用前景。本文基于液膜动力学、气泡动力学和传热学的基本原理,建立了描述微重力条件下喷雾冷却传热特性的理论模型。利用模型模拟的方法,对以水作为工质的微重力条件下喷雾冷却系统的被冷却表面温度分布、冷却曲线等因素进行了分析,分析结果显示:在单相区,重力条件对喷雾冷却的换热特性和表面温度分布不均匀性的影响较小;在两相区,由于微重力条件下气泡难以脱离等因素的影响,使得喷雾冷却的换热能力明显弱于常重力条件下的换热能力,并且被冷却表面的温度不均匀性增大。

Spray cooling is a promising candidate to provide high rate heat flux removal in spacecraft thermal control.A mathematical model of spray cooling in microgravity heat transfer characteristics was presented based on the fundamentals of dynamics and heat transfer.The heat transfer characteristics including spray cooling curve,temperature gradient on the heating surface and et al in microgravity were obtained by model analysis.The analyzed results shows that in one phase region,gravity has little effect in heat transfer characteristics and temperature gradient on the heating surface,while in two phase region,because that bubble is difficult to depart from the hot surface,heat transfer performace in microgravity falls behind with that in gravity and temperature gradient on the heating surface increases.