双D形流道内超临界二氧化碳传热特性数值研究

Numerical Investigation of Heat Transfer Characteristics of Supercritical Carbon Dioxide in Double D-Shape Channel

对简单双D形流道内超临界二氧化碳传热特性进行数值研究。重点研究了热流体质量流速对换热功率和换热效能的影响,以及热流道失流工况对传热特性的影响。研究表明:随着热流体质量流速增加,换热器换热功率增加,换热器换热效能降低;换热器的换热能力受冷热流体温差驱动,热流体失流时换热器换热能力下降,壁面温度降低,与定热流密度传热存在一定差异。

This paper presents the results of numerical investigation of the heat transfer characteristics of the supercritical carbon dioxide in double D-shape channel. The capability and thermal efficiency （e） are affected obviously by the mass flow rate of the working fluid, which were studied closely here. The study shows that as the mass flow rate is slow down in the hot channel, the capability decreases and the thermal efficiency raises up. Heat transfer in the heat exchanger is driven by the temperature difference, so when the hot mass flow rate slowing down, the heat flux becomes weak and the wall temperature drops down. This phenomenon is different from the fixed heat flux heat transfer.