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利用热力学第二定律对壁面温度恒定状态下的圆形流道、三角形流道和矩形流道内充分发展区层流对流换热过程进行了研究,得到了熵产数的一般表达式;定义了对流换热过程可用能损率,讨论了入口换热温差、流体温升和流动阻力对可用能损率的影响,并对几种典型流道内对流换热过程的热力学性能进行了比较;同时,从降低可用能损率的角度出发,得到了最小可用能损率所对应的最佳入口换热温差。
The second law of thermodynamics is used to study the laminar-flow convective heat transfer in a circular flow channel, a triangular flow channel and a rectangular flow channel with constant wall temperature. The general expression of entropy production number is obtained. The convection The energy loss rate can be used in the heat exchange process. The influence of inlet heat transfer temperature difference, fluid temperature rise and flow resistance on the available energy loss rate is discussed. The thermodynamic performances of convection heat transfer in several typical flow paths are compared. At the same time, Reduce the available energy loss from the point of view, obtained the minimum available loss corresponding to the best inlet heat transfer temperature difference.