Numerical modeling and thermal enhancement of finned tube heat exchanger with guiding channel and fusiform configurations

摘要

As the air-side heat transfer is controlling the efficiency of finned tube heat exchanger (FTHX), this makes its enhancement important. After analyzing the thermal hydraulic performance of conventional plain plate fin, two novel air-side fin configurations are proposed. The first design guides more airflow into the back of the tubes and eliminates wake zones. The second design significantly enlarges the heat transfer area of air-side with little pressure drop penalty. Numerical investigations of conventional and novel fin designs are conducted. Based on the temperature and velocity flow fields and Nusselt number (Nu), the two novel designs are repeatedly improved. Comparing Nu and friction factor (f) with the plain plate fin, the two novel fin designs enhance the overall thermal performance by 103.1-109.0% and 64.5-78.4% respectively, while incurring pressure drop penalty of 312.8-419.6% and (- 1.5)-6.0% respectively. As such, the proposed enhanced air-side fin designs are promising candidates for improving the efficiency for FTHXs.