两相流微通道换热特性的仿真与实验研究

发布时间：2018-06-11 20:36

本文选题：微通道 + 数值仿真　；参考：《电子科技大学》2016年硕士论文

【摘要】：随着新兴的MEMS技术不断发展,电子器件的特征尺寸逐步进入亚微米量级。高性能IC芯片由于空间热流密度不均而形成的局部热点提高了芯片的最高结温,严重地降低了电子设备的性能和可靠性。两相流微通道散热器可以有远超100W/cm2的散热效率,而且具有更好的温度一致性、更小的体积和更少的冷却剂用量等优点。为了进一步加深对微通道内两相流动换热特性的认识和弥补实验研究方式的不足,对微通道两相流动展开数值仿真研究具有十分重要的意义。本文在分析了微尺度效应和流动传热基本理论的基础上,围绕微通道内两相流动的换热特性,主要完成了以下几方面的内容:(1)与之前使用实验方式研究微通道两相流现象不同,本文主要考虑采用数值仿真方法对微通道两相流动现象进行研究,提出了一套针对微通道内流动沸腾现象的数值仿真方法。仿真方法考虑到了微通道内的低雷诺数效应和相变过程质量转移,可以较为真实地仿真微通道两相流动的换热和压降特性。(2)在提出微通道流动沸腾数值仿真方法的基础上,对微通道内两相流动换热特性展开仿真研究。主要针对入口速度、制冷工质、微通道的几何形状参数等因素设置参照进行数值仿真,依据仿真结果研究其对两相流动换热特性的影响。(3)为了对流动沸腾数值仿真结果进行对比分析,成功设计加工了微通道两相流动实验系统,解决了小体积大功率热源模拟,实验装置的组合设计和结构密封难题。为微通道两相流动实验设计了标准实验步骤,对微通道流动沸腾过程中的温度、压力数据进行了采集和分析。实验结果表明,数值仿真方法对微通道两相流动过程的仿真与实验数据较为吻合,验证了微通道数值仿真方法的有效性。
[Abstract]:With the development of MEMS technology, the characteristic size of electronic devices has gradually entered sub-micron order. The high performance IC chip due to the uneven space heat flux caused by the local hot spots increased the highest junction temperature of the chip and seriously reduced the performance and reliability of electronic equipment. The two-phase flow microchannel radiator has the advantages of far more than 100 W / cm ~ 2 heat dissipation efficiency, better temperature consistency, smaller volume and less coolant consumption. In order to further understand the heat transfer characteristics of two-phase flow in microchannels and make up for the deficiency of experimental research, it is of great significance for the numerical simulation of two-phase flow in microchannels. Based on the analysis of the microscale effect and the basic theory of flow heat transfer, this paper focuses on the heat transfer characteristics of two-phase flow in microchannels. The main contents of this paper are as follows: (1) the phenomenon of two-phase flow in microchannels is different from that in previous experiments. In this paper, the numerical simulation method is mainly used to study the two-phase flow in microchannels, and a set of numerical simulation methods for the flow boiling phenomenon in microchannels are proposed. Considering the effect of low Reynolds number and mass transfer of phase transition in microchannel, the simulation method can simulate the heat transfer and pressure drop of microchannel two-phase flow. The heat transfer characteristics of two-phase flow in microchannels are simulated. The numerical simulation is mainly carried out according to the input speed, refrigerant, geometric parameters of microchannel and so on. In order to compare and analyze the numerical simulation results of flow boiling, a microchannel two-phase flow experimental system was successfully designed and machined to solve the small volume high-power heat source simulation. The combination design and structural sealing problem of experimental device. Standard experimental steps were designed for microchannel two-phase flow experiment. The temperature and pressure data of micro-channel boiling process were collected and analyzed. The experimental results show that the numerical simulation method is in good agreement with the experimental data, and the validity of the numerical simulation method is verified.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK124

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