折流板几何结构对换热器性能影响的数值模拟

Numerical Simulation of Heat Exchanger Performance with the Different Geometric Structures of Baffles

应用标准k-ε湍流方程模型,使用压力修正的SIMPLE算法进行求解,对弓形折流板不同几何结构下换热器壳程的流动和换热性能进行了数值模拟,并对计算结果进行了分析.结果表明:换热器入口速度的增加会使折流板之间的高温区域减少、流动死区面积减少、换热器的有效换热面积增大;随着折流板间距减小,换热器的换热量随之增大,但是换热器的压降却明显增加,折流板换热器压降均随空气入口速度的增加呈递增趋势且会影响综合换热性能;折流板高度的增加对换热量有明显增大的作用,但是折流板增高会使壳程压降升高,从而造成了换热性能指标的下降.

Using the standard k-ε turbulence model as the model equations which adopts the SIMPLE pressure correction algorithm to solve it, the heat exchanger shell flow and heat transfer performance of segmental baffles with different geometric structures was simulated, and the results were analyzed. The results showed that. increasing the inlet speed of the heat exchanger reduced the high temperature zone between baffles,and the flow dead zone, but increased the effective of heat transfer area; decreasing the baffle spacing increased the heat transfer rate, but increased the pressure drop along the heat exchanger significantly baffle heat exchanger, with increasing air inlet velocity tendency to affect the consolidated exchange thermal properties; increasing the baffles＇ height increased the heat transfer capacity significantly , but increased the baffle shell fluid pressure drop, resulting in the decrease of heat transfer performance .