TEMPERATURE DISTRIBUTION IN INTERNALLY HEATED WALLS OF HEAT EXCHANGERS WITH NONCIRCULAR FLOW PASSAGES USING COOLANTS WITH VERY LOW PRANDTL NUMBER

摘要

A method for the determination of the temperature distribution within the coolant and the passage walls for a special type of heat exchanger is presented. The heat exchanger is composed of polygonal flow passages which are heated uniformly by internal heat sources. The Prandtl number of the coolant flowing through the passages is postulated to be so low that the turbulent contribution to the heat flow within the fluid can be neglected. The differential equation describing the heat flow by conduction is solved by the relaxation method. Numerical com putations are carried out for a triangular and a rectangular passage shape. The resulting ratio of the temperature differences within the passage walls to the difference of the wall temperature and the fluid bulk temperature is considerably larger than the temperature ratio in similar heat exchangers using a coolant with a Prandtl number in the neighborhood of 1.