扇叶型折流板换热器壳程性能及传热机理的数值模拟

Numerical simulation of shell side performance and heat transfer mechanism of blade baffle heat exchanger

利用数值模拟方法比较分析了扇叶型折流板换热器及螺旋折流板换热器流动传热性能及传热机理。结果表明:两种换热器壳程流动状态相近,流体倾斜于管束流动;扇叶型折流板换热器壳程传热系数和压降大于螺旋折流板换热器;雷诺数2 500—5 500时扇叶型折流板换热器综合性能低于螺旋折流板换热器,当雷诺数大于6 500时扇叶型折流板换热器综合性能略高于螺旋折流板换热器;扇叶型折流板换热器内壳程流体要比螺旋折流板换热器中的壳程流体更早的进入充分发展阶段,导致扇叶型折流板换热性能较高;扇叶型折流板换热器壳程流体流场和温度场协同性优于螺旋折流板换热器,因此前者具有更好的对流传热性能。

The fluid flow heat transfer performance and mechanism of blade baffle and helical baffle heat exchanger are analyzed by numerical simulation. The results show that the shell flow of the blade battle is similar to that of the hehical baffle heat exchanger,which is inclined to the tube bundle. The heat transfer coefficient and pressure drops of blade baffle heat exchanger are larger than that of helical baffle heat exchanger. When Reynolds number is in the range of 2 500—5 500,the comprehensive performance of blade baffle heat exchanger is lower than that of helical baffle heat exchanger. When the Reynolds number is greater than 6 500,the comprehensive performance of blade baffle heat exchanger is slightly higher than that of helical baffle heat exchanger. The shell-side fluid in blade baffle heat exchanger enters the stage of full development earlier than that of helical baffle heat exchanger,which results in high heat transfer performance of helical baffle heat exchange. The fluid flow field and temperature field synergy in shell side of the blade baffle heat exchanger is superior to that of the helical baffle heat exchanger,so the former has better convective heat transfer performance.