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ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

NUMERICAL SOLUTIONS FOR A MULTIPLE-CHANNEL COUNTERFLOW HEAT EXCHANGER WITH SPACE-DEPENDENT WALL HEAT DISSIPATIONS

Get access (open in a dialog) DOI: 10.1615/IHTC8.1330
pages 2823-2828

Abstract

A numerical analysis is made for a multiple-channel counterflow heat exchanger. Space-dependent heat dissipations, space-dependent heat transfer coefficients, and axial wall heat conduction were included in the analysis. This study is an extension to a previous analytical investigation which shows that a two-channel counterflow system has two major advantages over the parallel flow system. The advantages are (1) reduction of the maximum temperature of the heat generating wall and (2) reduction of the maximum wall temperature difference in the system.
In this analysis, a finite difference scheme was employed to evaluate the differential equations describing the heat transfer phenomena within the system under steady-state conditions. A numerical solution rather than an analytical solution is sought because of the mathematical complexity involved in treating the coupling problem between the fluid temperatures and the wall temperatures in the multiple channels. Because of limited space, the numerical results are presented only for some common cases where the heat dissipations are (1) a linear function of space, (2) an exponential function of space, and (3) a cosine function of space. A comparison between the present finite difference solution and the previous analytical solution for the two-channel counterflow system is also made to verify the accuracy of the present results.