Abstract:

For the stability of plate heat exchanger in the dynamic ice storage system, Fluent is employed to investigate the variation rules of the heat transfer coefficient, temperature distribution and pressure drop parameters under the plate structure with different pitches, heights and angles of corrugated plate. The results indicate that: At smaller corrugation pitch (6 mm), the number of contact points increases, which leads to a enhancement of heat transfer and a more uniform temperature distribution; The increase of the corrugation height can increase the heat transfer area of the corrugated plate, but also leads to the flow velocity slowing down and the generation of high temperature stagnation zone, which is not conducive to improving the heat transfer efficiency of the corrugated plate; The change of corrugation angle effects the flow shape in plate heat exchanger. With the increase in the angle of the corrugation from 60° to 150°, the heat transfer efficiency is firstly elevated and then lowered. There is the best heat transfer effect at 120°. The complex flow with a large proportion of zigzag flow accompanied by cross flow has a more efficient heat transfer.

Key words: plate heat exchanger, supercooled water, flow and heat transfer, dynamic ice storage

摘要：

针对动态蓄冰系统中板式换热器的运行稳定性问题，利用Fluent对水侧流道进行流场和温度场的模拟分析。在波纹节距为6~12 mm、波纹高度为1.4~2.8 mm、波纹夹角为60°~150°的8个工况下进行模拟，探究了不同波纹节距、高度和角度的板片结构下流场流型、温度分布和压降等参数的变化规律。结果表明：在较小的波纹节距（6 mm）下，接触点数量更多，流场内扰动大、换热好，温度分布也更加均匀；比较不同波纹高度下的换热效果发现，虽然波纹高度的增加可以增大波纹板的换热面积，但同时也会导致流速减慢和高温滞留区的产生，不利于提高波纹板的换热效率；波纹夹角的改变影响了流场内的流型，随着波纹夹角从60°增大到150°，换热效果先升高后降低，当波纹夹角为120°时换热效果最好。通过分析不同夹角时板内流场的流型，发现在较大占比的曲折流中伴随十字交叉流动的复合流动具有更好的换热效果。

关键词: 板式换热器, 过冷水, 流动换热, 动态蓄冰