湍流_传递方程及其应用

导出了湍流火用传递方程组 ,依此研究了壁面常热流对流换热管的火用传递 ,计算了由于粘性耗散、径向和轴向导热引起的火用损率分布。通过对单位体积总火用损率的计算表明 ,单位体积总火用损率是换热管几何参数和边界条件的多元函数 ,对于给定的几何参数 ,存在使单位体积总火用损率最小的边界条件 ,反之亦然。该结论对优化设计换热器及对给定边界条件的换热器优化选取具有一定的指导意义。

Exergy Transfer Equation for Turbulent Flows and Its Applications

The authors have derived an exergy transfer equation for turbulent flows. On this basis a study was conducted of the exergy transfer for a convection heat exchange tube with a wall surface constant heat flux. The distribution of exergy loss rate caused by viscosity dissipation, radial and axial heat conduction was calculated. The calculation results of the total exergy loss rate for a unit volume indicate that the total exergy loss per unit volume is a multi value function of heat exchange tube geometric parameters and boundary conditions. For a given geometric parameter there exists a boundary condition, which gives a minimum value of the total exergy loss rate for a unit volume, and vice versa. The above conclusion can to a certain extent serve as a guide for the optimized design of heat exchangers and the optimal selection of heat exchangers under given boundary conditions.