气液两相态的蒸发冷却介质绝缘特性与热力学参数的交叉影响及机理研究

项目名称： 气液两相态的蒸发冷却介质绝缘特性与热力学参数的交叉影响及机理研究

项目编号： No.51307157

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 电工技术

项目作者： 牛文豪

作者单位： 中国科学院电工研究所

项目金额： 26万元

中文摘要： 气液两相流的绝缘问题存在于众多工业领域，但其绝缘特性和放电机理尚缺乏系统深入的研究。已有研究表明：液氮和蒸发冷却介质在气液两相流下的绝缘特性存在相似规律，均与其热力学参数密切相关。本项目研究并揭示高热流密度下汽锁效应的发生机理，确定汽锁效应下各电学、热力学物理量的定量表达关系。以气液两相流绝缘特性的实验数据为依据，考虑气泡的形态和极化、荷电等情况，结合蒸发冷却介质气态、液态等单相流的绝缘特性和气液界面的沿面放电特性，建立能重现实验结果的电场、温度场、流场的多物理场耦合模型，通过理论计算和分析研究，明确气液两相流的放电机理。本项目是高电压绝缘、气体放电与传热学的交叉研究，具有科学意义和实用价值，所发现的新规律和机理将推动低温电工学和蒸发冷却高压电气设备等相关领域的基础研究与工业应用。

中文关键词： 气液两相流；汽锁效应；热流密度；击穿电压；临界直径

英文摘要： Although it exits in many industrial fields, the insulation characteristics and breakdown mechanism in thermal bubble induced two-phase flow condition have not been known clearly so far. The existing research of liquid nitrogen and evaporative coolant illustrate that the insulation characteristics of two-phase flow are related closely to thermodynamic parameters. The emerging mechanism of vapor lock will be studied and revealed, with the quantitative relation expression of electrical and thermal parameters being established. Based on the test result of insulation characteristics of two-phase flow, considering the pattern, polarization and charge of the bubbles, and the insulation characteristics of vapor, liquid and the interface of evaporative coolant, a coupling model of multiphysics fields such as electric field, thermal field, flow field, will be founded to calculate，analyze and identify the breakdown mechanism of the two-phase flow. This project is a cross study of high voltage insulation technology, gas discharege physics and heat transferring, possessing kinds of innovative significance and practical utility, which will promote the basic research and application of related industrial fields such as cryogenic electrical engineering and evaporative cooling high-voltage apparatus.

英文关键词： two-phase flow；vapor effect；heat density；breakdown voltage；critical diameter