基于火积理论的螺旋折流板换热器的优化结构分析

为了比较平面螺旋折流板换热器和折面螺旋折流板换热器的传热和阻力性能,应用了换热器常用评价标准PEC准则和火积理论对两种换热器实验结果进行了分析,同时采用火积耗散极值原理对两种换热器的传热火积耗散率、阻力火积耗散率以及总火积耗散率进行了对比。结果表明:火积耗散理论分析换热器性能的结果与传统换热器评价标准PEC准则相符,说明了火积耗散理论的可靠性;折面螺旋折流板换热器的综合性能得到了有效的改进,火积耗散率也均优于原始结构,表明折面螺旋折流板换热器的性能得到较大改善;两种换热器传热火积耗散率值要远远大于阻力火积耗散率,约为阻力火积耗散率的一千余倍,说明传热损失为换热器的主要不可逆损失。

Analysis on the Optimized Structure of the Helical Baffle Heat Exchanger by Entransy Theory

In order to compare the heat transfer and resistance performance of the planar spiral baffle plate heat exchanger and the folded spiral baffle plate heat exchanger,the experimental data were analyzed by PEC criterion and the entransy dissipation theory.At the same time,the entransy dissipation extremum principle was applied to compare the heat transfer entransy,resistance entransy dissipation and the total entransy dissipation of the two kinds of heat exchanger.The results showed that the consistency of the analysis results of the entransy dissipation theory and the rule of PEC,proving the reliability of the entransy dissipation theory.The comprehensive performance of the folded spiral baffle plate heat exchanger has been improved effectively,and the entransy dissipation rate is better than that of the original structure,indicating the performance of the folded spiral baffle heat exchanger is greatly improved.The heat transfer entransy dissipation rate of the two heat exchangers is far greater than the resistance entransy dissipation rate,which is about a thousand times of the resistance entransy dissipation rate,indicating the heat transfer loss is the main irreversible loss of the heat exchanger.