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【摘要】 对超临界二氧化碳在微细竖直圆管内冷却条件下的对流换热进行了数值模拟研究,分析了不同管径、进口雷诺数及不同的热流率对超临界二氧化碳对流换热的影响,考察管内局部流体温度、湍动能、湍流雷诺数的变化。湍流模型采用低雷诺数YS模型。研究表明,在临界温度区域比较大的截面,超临界二氧化碳局部传热系数达到最大值,同时管内传热受湍流雷诺数影响较大。 【Abstract】 Convective heat transfer of supercritical carbon dioxide flowing in miniature vertical tubes under cooling condition was investigated numerically.Different tube diameter,inlet Reynolds number and heat flux which effect the heat transfer of supercritical carbon dioxide were researched.The change profiles of fluid local temperature,turbulence kinetic energy and turbulent Reynolds number(Rey) along flow direction were obtained.The low Reynolds number turbulent model was simulated using YS model.The results show that the heat transfer coefficient reaches the largest where the region of large-property-variation coveres largest fluid fields.The heat transfer in tube was influenced bigger by turbulent Reynolds number. 【关键词】 二氧化碳; 模拟; 超临界; 对流换热 【Key words】 carbon dioxide; simulation; supericritical; convective heat transfer