收缩式角孔通道对板式换热器流动均匀性的影响

针对传统板式换热器流道之间流量分配不均的问题,提出新型收缩式角孔通道结构。按照收缩式角孔所处位置的不同,建立入口设置、出口设置、入口和出口同时设置收缩式角孔通道的板式换热器物理模型;通过全三维数值模拟,以水为流动介质,研究具有收缩式角孔通道结构的板式换热器流量分布特性和流动均匀性;利用相对标准差对板式换热器整体流动均匀性进行评价。结果表明:传统板式换热器入口角孔通道末端存在涡流区,通过入口设置收缩式角孔通道结构有效避免了涡流区的产生,使得流场分布均匀;与传统板式换热器相比,入口设置收缩式角孔通道的板式换热器相对标准差减小16.7%～28.7%,并且随流量变化稳定。

Effect of Tapered Manifold on Flow Uniformity of Plate Heat Exchangers

A new type of tapered manifold is proposed aiming at the problem of flow maldistribution in the flow channels of the traditional plate heat exchangers. According to the position of the tapered manifold, it was divided into three cases: inlet arrangement, outlet arrangement, inlet and outlet arrangement. Through the three-dimensional numerical simulation, the flow distribution characteristics, flow uniformity and total pressure drop were studied. The flow uniformity of the heat exchanger was evaluated by the relative standard deviation. The results show that there is a vortex zone at the end of the inlet manifold of the traditional plate heat exchanger, and the inlet arrangement of the tapered manifold avoids the generation of the eddy current zone. Compared with the traditional plate heat exchanger, the relative standard deviationof the new U-in plate heat exchanger is reduced by 16.7%~28.7%, and the pressure drop is reduced by 2.6%~6.5%.