Parameter study on the fouling characteristics of the H-type finned tube heat exchangers

In this paper, numerical simulations were performed for the fouling characteristics and heat transfer performance after fouling on the H-type finned tube heat exchangers, and the optimum parameters studies were also conducted according to the orthogonal array design method. Firstly, the effect of row number on the fouling results were discussed. It was found that there was a critical row number N_cr = 6, and the fouling results will reach a constant value when the row number is larger than the critical row number. Then, the orthogonal array design method was employed to design the test arrangements, and the effects of six geometric parameters and two operating conditions on the fouling results as well as heat transfer performance after fouling were investigated. The order of the effects of each factor and the optimum parameters corresponding to the least fouling and best heat transfer performance after fouling were also determined. At last, a correlation of the Nusselt number after fouling Nu_f^∗ with the geometric parameters and the operating conditions was obtained. The results showed that the optimum conditions we determined using the orthogonal array design method do have less fouling or have better heat transfer performance after fouling than the reference cases in the test arrangements. The correlation of Nu_f^∗ has good prediction accuracy, and it can be useful in the design and evaluation of heat exchanger in dusty environment.