带45°肋矩形通道冷却性能及熵产特性实验研究

Experimental Study on Cooling Performance and Entropy Generation Characteristics of Rectangular Channels with 45°Ribs

以带45°肋矩形通道为研究对象,实验测量了通道进、出口温度和压力以及壁面温度,分析了雷诺数(Re=10000~60000)和宽高比(W/H=0.25~4)对通道内冷气流动和传热性能及其引起的不可逆熵产的影响规律,对比了蒸汽冷却和空气冷却的不同。研究表明:不同雷诺数时,蒸汽冷却的传热性能较空气冷却提高了25%~33%;蒸汽冷却的综合热力性能要好于空气冷却,且最优宽高比为0.5。传热不可逆熵产占总熵产的50%以上,是不可逆熵产的主要来源。与空气冷却相比,蒸汽冷却引起更小的摩擦不可逆熵产和更大的传热不可逆熵产。

In this paper,rectangular channels with 45°ribs are taken as the research object.The inlet and outlet temperature,pressure and wall temperature of the channels are measured experimentally.The effects of Reynolds number(Re=10000-60000)and aspect ratio(W/H=0.25-4)on flow and heat transfer performance and irreversible entropy generation of the coolants are analyzed.The differences between steam cooling and air cooling are compared.The results show that the heat transfer performance of steam cooling is 25%-33%higher than that of air cooling at different Reynolds numbers;the comprehensive thermal performance of steam cooling is better than that of air cooling,and the optimal aspect ratio is 0.5.Heat transfer irreversible entropy generation accounts for more than 50%of the total entropy generation,which is the primary source of irreversible entropy generation.Compared with air cooling,steam cooling causes less friction irreversible entropy generation and greater heat transfer irreversible entropy generation.