湿工况下翅片管换热器火积耗散优化分析

An Entransy Dissipation-based Optimization Principle for Finned Tube Heat Exchangers in Wet Conditions

以传热,流动阻力和质交换引起的总火积耗散数最小为目标,以换热器芯体外形尺寸为优化变量,在给定热负荷的情况下,采用遗传算法对管内外工作流体分别为水和空气的套片式翅片管换热器进行优化。分析总火积耗散数与风机和泵功率,效能和传热单元数的关系。得到温度火积,压力火积和湿度火积占总火积耗散数的百分比关系,并将模拟数据与实验数据作对比。结果表明:优化后传热火积耗散数,阻力火积耗散数和湿度火积耗散数均大幅减小,且后两者比传热火积耗散数减少的幅度更大。随着总火积耗散数的减小,换热器有效度有所增加,且消耗的风机与泵功率大幅下降,换热器整体传热性能得到提高。

It is taken the total entransy dissipation number caused by heat transfer, fluid friction and mass transfer as the objective function and the heat exchangers core dimensions as the optimization variables to optimize the finned tube heat exchangers by using genetic algorithms, which takes water and air as working fluids inside and outside of the tube. The relationship between the total entransy dissipation number and fin and pump power, effectiveness and the number of heat transfer is analysis and percentage of the total entransy dissipation number of the heat transfer, fluid friction and latent humidity dissipation number is obtained. And simulation date is compared with the experimental date. It is demonstrated that the heat transfer, fluid friction and latent humidity dissipation numbers are reduced by optimization and the decreasing range of the second and third are larger than that of the heat transfer entransy dissipation number. The heat exchanger effectiveness increases, the power of the fan and pump reduces significantly, and the integrated heat transfer performance of heat exchanger improves as the total entransy dissipation number decreases.