二次封头结构板翅式换热器出口温度分布的实验研究

在对板翅式换热器内部物流分配不均匀研究的基础上，进一步研究了不同工况下二次封头结构换热器出口温度分布的规律．实验结果表明：随着Re的增大，换热器出口温度分布与流量分配趋势相一致，会越来越不均匀；较大的传热温差也会增加温度分布的不均匀性．通过比较二次封头和普通封头换热器截面温度分布情况发现：二次封头结构明显地改善了换热器出口截面温度分布，尤其在大RP下，温度分布不均匀性的改善效果更加显著，同时换热效能可增加7％左右．

Experimental Study on Outlet Temperature Distribution in Plate-Fin Heat Exchangers under Secondary Header Configuration

Based on our study on the flow maldistribution in a plate-fin heat exchanger, the exit temperature distribution in the heat exchanger under the secondary header configuration was experimentally studied. The results show that the temperature change of the heat exchanger is consistent with flow pattern and the maldistribution is more and more severe with the increase of Re velues. In addition, larger temperature difference of heat transfer can enlarge the maldistribution of the temperature. By comparing the temperature distributions in the heat exchanger between the header construction with the secondary header and the traditional header configuration, it is found that the temperature distribution with the secondary header is obviously improved, and the improvement is more efficient under higher Re velues. The efficiency of the heat exchanger can been improved by about 7%.