微通道内种子汽泡抑制沸腾不稳定性研究  

Flow Boiling Instabilities Controlled by Seed Bubbles in Microchannels

作　　者：宗露香[1] 徐进良[2] 刘国华[3] 

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 [3]安徽工业大学能源与环境学院,马鞍山243002

出　　处：《农业机械学报》2014年第3期341-346,共6页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金国际合作与交流资助项目(51210011);国家自然科学基金-广东联合基金资助项目(U1034004)

摘　　要：搭建同步光学可视化实验台，以并联三角形微通道硅基热沉为实验段，微通道人口玻璃盖板内侧溅射5个Pt微加热器构成种子汽泡发生器阵列。研究了低人口质量流量下不同种子汽泡触发频率对微通道内沸腾不稳定性的影响。实验结果表明，种子汽泡触发频率作为控制微通道内流动沸腾不稳定的重要参数，单相液体区域，种子汽泡对微通道内流动影响很小；两相区域，随着热流密度增大，压降呈线性上升，壁面温度呈指数式上升。触发频率越高，压降越高，壁面温度下降越大。相同热流密度条件下，高频种子汽泡能够完全消除沸腾不稳定性，壁面温度显著下降，温度均匀性得到明显提升。A simultaneous optical visualization experimental system was set up, and a parallel triangle silicon microchannel heat sink was used as the test section. Five platinum film microheaters was etched at the top glass cover surface and located at the mierochannel entrance, acting as a seed bubble generator array. The microscale flow boiling instability under different seed bubble frequencies was experimental examined. The results show that the seed bubble frequency is an important parameter to control flow boiling instability. In the single liquid flow region, seed bubbles have negligible effect on flow. In the two-phase flow region, with heat flux increasing, pressure drop increases linearly and the temperature of the heating wall surface increases exponentially. Moreover, higher pressure drop could be approached with lower wall temperatures and higher bubble triggering frequency. With the same heat flux, the seed bubbles triggered with high frequency can completely eliminate flow boiling instabilities, heating wall temperature could be dramatically decreased, and the uniformity of the temperature could be promoted significantly.

关 键 词：微通道 沸腾不稳定性 种子汽泡 触发频率 

分 类 号：Q813.11[生物学—生物工程]