Parametric investigation and correlation development for thermal-hydraulic characteristics of honeycomb 4H-type finned tube heat exchangers

Abstract

The key to the design of dusty flue gas heat exchangers is to enhance heat transfer and solve the fouling problem. In this paper, a honeycomb 4H-type finned tube heat exchanger (FTHE) was proposed. A three-dimensional numerical investigation was conducted on heat transfer and flow friction characteristics of honeycomb 4H-type FTHEs. Firstly, the flow field and temperature of H-type FTHEs with inline and honeycomb arrangements were analyze. Then, the effect of different structural parameters (oblique tube pitch, fin height, slit width, fin pitch and fin thickness) and Re number were analyzed. Finally, the predicted correlations of Nu number and Eu number of honeycomb 4H-type FTHEs were obtained based on the multiple regression method and 105 sets of numerical data. The results show that the thermal-hydraulic performance of honeycomb 4H-type FTHEs is superior to that of aligned single H-type FTHEs. Through parametric analysis, it is found that Nu number is only negatively correlated with oblique tube pitch, and Eu number is negatively correlated only with fin pitch and slit width. Besides, the average error of correlations of Nu number and Eu number is less than 3%, which provides practical guidance for efficient recovery of industrial waste heat.