梯级针肋硅基微通道流动沸腾稳定性实验  

Experiment of Flow Boiling Stability in the Gradient Distribution Pin Fin Silicon-Based Microchannel

作　　者：金武[1,2] 余雄江 徐进良[1,3] 

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]华北电力大学可再生能源学院,北京102206 [3]华北电力大学能源动力与机械工程学院,北京102206

出　　处：《微纳电子技术》2016年第12期807-815,共9页Micronanoelectronic Technology

基　　金：国家自然科学基金资助项目(51436004);国家自然科学基金委国际合作项目(51210011)

摘　　要：制作了一种微针肋疏密梯级排布的硅基微通道,通道由11个针肋区以及10个无针肋通道组成,其中微针肋是15μm×15μm的正方形立柱。进行了以丙酮为工质的流动沸腾实验研究。实验研究在下列条件下进行:入口温度为47.4~52.5℃,质量流速为154~276 kg/(m^2·s),有效热流密度为27.22~224.29 kW/m^2。结果表明梯级针肋微通道使沸腾系统入口压力波动和流体温度波动幅度小于1%,外壁温波动幅值小于0.5℃。观察到梯级针肋微通道中特有的气液两相流动,例如产生于针肋密集区的核化气泡向两侧无针肋通道交替排散;无针肋通道中截面含气率类正弦的张弛波动。提出通道充满比的概念,采用集中参数法,建立简化传热模型,说明了通道充满比与壁温、传热系数的耦合反馈关系,解释了梯级针肋微通道结构具有高流动沸腾稳定性的机理。The gradient distribution pin fin silicon-based microchannel was fabricated,containing11 pin fin areas and 10 no pin fin channels.The micro pin fin in the channel is the square column with the section of 15μm×15μm.The flow boiling experiment with acetone as the working fluid was performed.The experiment was carried out under the working conditions i.e.the inlet fluid temperature of 47.4~52.5 ℃,the mass flow rate of 154~276 kg/（m^2·s）,and the effective heat flux of 27.22 ~224.29 kW/m^2.The results show that due to the gradient distribution pin fin microchannel,the fluctuation amplitudes of the boiling system inlet pressure and fluid temperature were less than 1%,and the fluctuation amplitude of the outside wall temperature is less than 0.5 ℃.The unique gas-liquid two-phase flow in the gradient distribution pin fin microchannel was observed,such as the alternating dispersion of the nucleation bubble from the dense pin fin area to no pin fin channel on both sides and the sine-like fluctuation of the section void fraction in the no pin fin channel.The concept of the channel filling ratio was presented,the simplified model of flow heat transfer was established by the lumped parameter method,illustrating the coupling feedback relationships of the channel filling ratio and wall temperature,the channel filling ratio and heat transfer coefficient,and revealing the mechanism of the gradient distribution pin fin microchannel with the high flow boiling stability.

关 键 词：微通道 梯级针肋 流动沸腾 稳定性 充满比 集中参数法 

分 类 号：O35[理学—流体力学] TH703[理学—力学]