高热流作用下微通道内种子气泡热控沸腾传热数值模拟  

Numerical Simulation of Seed Bubble Thermal Control Microchannel Boiling Heat Transfer under High Heat Flux

作　　者：宗露香[1] 徐进良[1,2] 王晓东[1] 孙东亮[2] 

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,北京102206 [2]华北电力大学低品位能源多相流与传热北京市重点实验室,北京102206

出　　处：《机械工程学报》2013年第14期125-132,共8页Journal of Mechanical Engineering

基　　金：国家自然科学基金广东省联合重点基金(U1034004);国家自然科学基金国际合作交流(512101064);国家自然科学基金(51106049)资助项目

摘　　要：深入研究种子气泡触发微通道流动沸腾传热机理。基于一种精确简单气液相变模型,运用流体体积函数方法对高热流密度下微圆管内种子气泡触发沸腾传热进行数值模拟。种子气泡在四种触发频率下进入微圆管。模拟结果表明,种子气泡触发频率是影响系统传热和稳定关键因素之一。低频(≤100 Hz)下,种子气泡抑制壁面温度波动不稳定性效果不明显,壁面过热度随时间呈大幅毫秒级波动;高频(1 000 Hz及以上)下,随着触发频率增加,壁面过热度振荡现象逐步成功得到抑制,恒热流加热壁面温度降至极限值。但触发频率存在饱和值(f=2 000 Hz)。通过对饱和触发频率下微通道内稳态时刻流型、局部传热系数进行分析发现,微通道内实现连续相变换热,拉长气泡区域局部传热系数维持在单相换热时2～3倍。Since the mechanism of seed bubble triggering boiling flow heat transfer in microchannels could not be understood comprehensively, the volume of fluid（VOF） method is used to simulate the seed bubble triggering boiling flow in a circular microchannel under the high heat flux for four triggering frequencies. An accuracy and simple vapor-liquid phase change model is proposed to treat boiling flow process properly. Simulation results show that triggering frequency is one of the key parameters to control system heat transfer and stability. At low frequency（≤100 Hz）, seed bubbles contribute least effects, and wall superheats vary with apparent millisecond-level fluctuation amplitudes. At high frequency（1 000 Hz or higher）, with the frequency increasing, the fluctuation amplitude of wall temperatures can be successfully suppressed, the heating wall superheats attains the minimum degree. But triggering frequency can approach the saturation value（f = 2 000 Hz）. In addition, the transient flow patterns and local heat transfer coefficient during the stable stage for saturated frequency are studied, continuous phase change heat transfer can be achieved, and the local heat transfer coefficient in the elongated bubble regimes can sustain 2-3 times the single liquid flow heat transfer.

关 键 词：触发沸腾 微通道 相变模型 数值模拟 

分 类 号：TK121[动力工程及工程热物理—工程热物理]