板式换热器内两相流流量分配的模拟及实验验证

Simulation and Experimental Validation of Two-Phase Flow Distribution in Plate Heat Exchanger

针对带有分配器的钎焊板式换热器内各支路的气液流量分配特性建立了预测模型.基于各支路的压降平衡方程,分别建立了板间流道和分配器流道压降计算模型;基于分配器处的气液分离关系方程,分别建立了两相流体在分配器处相分离和在分配器入口处液膜分布的计算模型.通过将压降平衡方程、气液分离方程分开迭代计算,开发了适用于模型的求解算法.模拟结果与实验测试数据对比表明,换热器总压降的相对误差在±20%以内,两相区高度的相对误差在±13%以内.

A mathematic model was developed in this paper to predict the two-phase flow distribution char acteristics in a plate heat exchanger. The submodels of the pressure drops in both the channel and the distributor were established based on pressure balance equations. The submodels of both the phase split in distributor and the liquid film distribution in the inlet of distributor were established based on phase separation equations. The algorithm of the mathematical model was developed by interatively solving the pressure drop balance equations and the phase separation equations respectively. The predictions of the model were compared with the experimental data. The relative errors of pressure drop between mathematic model and experimental data are within ±20%. The relative errors of two-phase region height between mathematic model and experimental data are within ±13%.