The comparison of longitudinal wall conduction effect on the crossflow heat exchangers including three fluid streams with different arrangements

This study investigates the effect of longitudinal wall conduction on a cro ssflow heat exchanger including three fluid streams with three different ar rangements. By using numerical method, this study calculates the exit mean temperature of each fluid stream and then computes the deterioration factor of each fluid stream in each arrangement. The results indicate that the ef fect of longitudinal wall conduction for fluid stream 3 in first arrangemen t is more severe than that in second arrangement when the heat capacity rat e ratio of fluid stream I is same to that of fluid stream 3. The deteriorat ion factor of fluid stream 2 is affected slightly by the change of inlet te mperature of fluid stream 3 in first and second arrangements. Besides, the longitudinal wall conduction strongly deteriorates the thermal performance of heat exchangers including three fluid streams at lower heat capacity rat e ratios. (C) 2001 Elsevier Science Ltd. All rights reserved.