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建立了内径为2 mm的三叶管三维模型,使用ANSYS Fluent软件对超临界二氧化碳在三叶管内的对流换热特性进行了研究,分析了流动方向、进口雷诺数、壁面热流密度和冷却压力等因素对局部换热系数的影响,结果表明:在本文研究的范围内,流动方向对超临界二氧化碳在三叶管内局部换热系数的影响较小,可以忽略,进口雷诺数、壁面热流密度和冷却压力对局部换热系数的影响较大;二氧化碳进口雷诺数越高,对应的局部对流换热系数也越高,壁面热流密度的大小对局部换热系数出现峰值位置有较大影响,对其大小影响不大;超临界二氧化碳冷却压力越高,对应的局部对流换热系数的峰值也越大;局部对流换热系数峰值所对应的温度只与冷却压力下的临界温度有关。
The three-leaf clover model with an inner diameter of 2 mm was established. The convection heat transfer characteristics of supercritical carbon dioxide in a clover tube were studied using ANSYS Fluent software. The flow direction, inlet Reynolds number, wall heat flux and cooling pressure The results show that the flow direction has little effect on the local heat transfer coefficient of supercritical carbon dioxide in the clover tube, which can be neglected. The inlet Reynolds number, wall heat flux and cooling The higher the Reynolds number of carbon dioxide is, the higher the corresponding local convection heat transfer coefficient is, the greater the influence of pressure on the local heat transfer coefficient is. And the corresponding peak value of the local convection heat transfer coefficient is larger. The temperature corresponding to the peak value of the local convection heat transfer coefficient is only related to the critical temperature under the cooling pressure.