Experiment on forced convection-condensation heat transfer characteristics based on finned plate configuration

Experimental investigation of forced convection-condensation heat transfer and flow characteristics based on finned plate heat exchanger for condensing heat recovery was studied. With the experimental data, the effect of outlet flue gas temperature and velocity on condensation performance was studied, and the performance curves of Reynolds number-Nusselt number and Reynolds number-friction factor have been obtained. Meanwhile, the comparison of experimental results between wind tunnel test (using air as working fluid) and condensation test (using flue gas as working fluid) was also presented. From these results it can be seen that, due to the extensive non-condensable gas (about 92%), enhancement of overall heat transfer performance is not obvious, and the forced convection-condensation heat transfer coefficient is 10%-20% times more than that of the forced convection without condensation. A heat transfer criterion-based relational expression under the operating condition was also obtained. These results provide insight into improved designs of finned plate heat exchangers for condensing heat recovery.