Shell-side single-phase flows and heat transfer in shell-and-tube heat exchangers. 3rd Report. Experimental study on axial and circumferential distribution of local heat transfer coefficients around a tube bundle.

Abstract

An experimental investigation is performed to find the axial and circumferential distribution of local heat transfer coefficients around a tube bundle in segmentally turbular heat exchangers. The variation in the axial distribution of the heat transfer coefficient is found to be negligible compared with that of circumferential distribution or that within the tube bundle. Local heat transfer coefficients are sensitive to the ratio of the inlet nozzle diameter to the shell diameter in the inlet nozzle region of the tube bundle, while they remain invariant in the center region. No remarkable decrease of local heat transfer coefficients in the window zone is observed, so it is considered that there isn't any effective recirculation zones at the edge there. The normalization of the circumferential heat transfer coefficient using its averaged value keeps the distribution pattern unchanged with the Reynolds number, the ratio of inlet nozzle diameter to shell diameter and location of the tube within the bundle. These normalized values are assumed to agree with those of a tube bank of two dimensional array, with reasonable accuracy.