CAJ | 학술논문

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.
대초림계이양화탄재미세수직원관내냉각조건하적대류환열진행료수치모의연구,분석료불동관경、진구뢰낙수급불동적열류솔대초림계이양화탄대류환열적영향,고찰관내국부류체온도、단동능、단류뢰낙수적변화.단류모형채용저뢰낙수YS모형.연구표명,재림계온도구역비교대적절면,초림계이양화탄국부전열계수체도최대치,동시관내전열수단류뢰낙수영향교대.
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(Re_y) 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.