流量分布不均匀对板式换热器传热性能的影响

运用并联联箱流量分布精确解的结果 ,对流量非均匀分布导致板式热交换器典型运行工况下传热性能的下降作了计算和分析 :当冷、热流体进出口均位于换热器同一侧时 ,各分支通道的传热量不均匀性相当严重 ,但是总传热量变化不大 ;当两流体进出口分别位于换热器两侧时 ,传热分布的均匀性虽然有了明显改善 ,但总传热量却比按均匀分布计算偏低近 2 0 %。此外 ,还发现两侧流体流量的相对变化没有对传热量的分布状况带来明显的影响。实测结果亦表明 ,上述理论分析和计算是正确的

Influence of Uneven Flow Distribution on the Heat Transfer Performance of Plate Heat Exchangers

Based on the result analysis of the accurate solution of the flow distribution of parallel mainfolds, the performance lowering of plate heat exchangers in typical working condition induced by uneven flow distribution was calculated.When the inlet and outlet of the cold and hot flows were at the same side of the heat exchanger, although there was serious uneven heat transfer in the mainfolds,there were few changes in the total heat transfer performance. When the cold and hot flows were at each side of the plate heat exchanger separately, there were significant improvements in the uniform of heat transfer distribution, but the total heat transfer quantity was lower 20% than that of the calculated from the even distribution. It was found out that the relative change of the flow ratio of the two sides had no significant influence on the heat transfer performance. The measured result shows that the above theoretical analysis and calculation were correct.