管内湍流传质损机理分析

Mechanism Analysis of Exergy Destruction Due to Mass Transfer with Turbulent Flows Through a Duct

根据常温下充分发展湍流传递方程组 ,研究了壁面常质量流管内湍流传质损的机理 ,计算了由于粘性耗散、径向和轴向传质不可逆性引起的损率随流体的性质、雷诺数、边界条件数及空间位置的变化规律 .对单位长度总损率的计算表明 ,对给定的流体 ,单位长度总损率是传质单元几何参数、边界条件和雷诺数的多元函数 。

The mechanism of exergy destruction due to mass transfer with turbulent flows through a tube has been investigated according to the equations set of the exergy transfer for fully developed turbulent flows. The distributions of exergy destruction rates varying with fluid properties,Reynolds number,boundary conditions and spatial location due to viscosity,mass transfer in radial and in axis directions have been calculated. The calculation shows that for a given fluid the total exergy destruction per unit length for a duct depends on geometrical parameters,boundary conditions and Reynolds number,and therefore the design and optimum of a mass transfer system can be performed by minimizing the exergy destruction in the system.