The effects of nonuniform inlet fluid conditions on crossflow heat exchanger

The influences of uneven inlet flow and temperature conditions on performance of crossflow heat exchanger using supercritical pressure CO2 (S-CO2) as working fluid were investigated from the viewpoint of distributed coordination. The inlet flow maldistribution and inlet temperature nonuniformity in either side of both fluids could deteriorate or enhance heat transfer, and the deterioration or enhancement effect of both fluids could be superimposed. The inlet conditions with enhancement effect eases the uneven distributions of heat transfer coefficient and temperature difference, and improves the distributed coordination between them, and eventually enhances the heat transfer. The total heat transfer rate depends not only on the values of heat transfer coefficient and temperature difference, but also on their coordination. The distributed coordination analysis indicates that the uneven inlet flow and temperature conditions could be used to enhance heat transfer using the special characteristics of S-CO2 without a significant increase of pressure drop. The present work may provide a new way to the optimization design of heat exchanger for the fluids with sharply variable properties.