Abstract

In this paper, a simplified mathematical model is presented to predict the axial temperature distribution of fluids in a three-concentric tube heat exchanger. Calculation results are compared with experimental results to confirm accuracy. The objective of the study is to avoid temperature cross which is very likely to be occurred in triple-fluid heat exchangers. Thereby the designer can adjust the design parameters, e.g. geometric parameters of the exchanger, temperatures or fluid flow rates, so that the temperature cross does not occur. The result of calculating a case shows that at the tube length of 21.5 m, the temperature cross occurs between the hot fluid and the intermediate fluid at a certain position. The shorten tube length to 8.5 m yields desirable gain. EES code and calculation procedure in detail are presented in the current study.