便携式新型换热器折流板对传热效率影响分析

Analysis of Portable New-type Heat Exchanger Baffle on Heat Transfer Efficiency

为了规避传统管壳式换热器体积偏大且消耗较高等缺点,开发一种给天然气或页岩气井口加热的便携式新型蒸汽换热器。笔者简化其内部几何结构,采用Fluent仿真数值模拟方法对折流板间距、切率变化和换热器壳程对流传热系数的关系进行了研究。结果表明:壳程对流换热系数随着折流板间距的增大而减小,当折流板切率取定值,间距取61 mm时,换热器在流体产生较小压降情况下获得较大的壳程对流传热系数,换热效果相对最佳;壳程对流换热系数随着折流板切率的增大而变大,当折流板间距取定值,切率取25%时,换热器在流体产生较小压降情况下获得较大的壳程对流传热系数,换热效果相对最佳。最后为设计特定的天然气或页岩气井口管道加热所需的换热器提供了优化依据。

Most of shell and tube heat exchanger design based on traditional experiences have the issues of high weight and high energy consumption.The effects of heat transfer tube types,baffle spacing,and baffle plate cut rate on the heat exchanger convective heat transfer coefficient were studied by suing fluent simulation method.Increasing the baffle plate spacing will decrease the shell side convective heat transfer coefficient and the pressure drop.The heat exchanger was the most efficient when the baffle plate spacing was 61 mm.Meanwhile,the heat exchanger could get a larger convective heat transfer coefficient with smaller pressure drop under this condition.Increasing baffle plate cut rate would lead to decreased pressure drop.When the tube cluster cross-flow velocity was equal to the flow rate at the baffle window,the maximum shell side convective heat transfer coefficient was obtained.The maximum heat efficiency would be obtained with optimal baffle plate cut rate of 25%.Shell and tube heat exchanger design optimization method was proposed.