Hydraulic and Thermal Modeling and Optimization of Rectangular Finned Multi Stream Plate-Fin Heat Exchangers by Genetic Algorithm

The modeling and optimization of a rectangular finned multi stream plate-fin heat exchangers is presented in this paper. The proposed method for thermal modeling of this type of heat exchangers is based on uniform heat distribution along the plates. So, the heat streams are distributed along the multi stream heat exchanger based on two principles: equal quantity of stream channel distribution and uniform heat distribution in each of the channels. The geometric, thermal and hydraulic modeling and design of the multi stream heat exchanger is carried out based on rectangular fin specifications. The total annual cost (TAC), the summation of capital investment and operating and maintenance costs are regarded as objective function to be minimized. The main variables are heat exchanger core dimension such as length, width, height and the fin geometric parameters such as fin pitch and height. The genetic algorithm is utilized as optimization tool to minimize the total annual cost of the multi stream plate fin heat exchanger. The proposed method is applied to a case study. The results of the current method is compared with the literatures.