CFD modeling of compact offset strip-fin high temperature heat exchanger

This thesis deals with the development of a numerical model to predict the overall performance of an advanced high temperature heat exchanger (HTHX) design, up to 1000°C, for the production of hydrogen by the sulfur iodine thermo-chemical cycle. The present study considers an offset strip-fin type compact high temperature heat exchanger made of liquid silicon impregnated carbon composite (SiC). The ceramic matrix composite material (CMC) is manufactured by impregnating the silicon into the pores of the carbon composites. The prototype heat exchanger is designed to operate at a thermal power of 50 MW. The design is an offset strip-fin, hybrid plate compact heat exchanger. The two working fluids are helium gas and liquid salt (FLINAK). The offset strip-fin is chosen as a method of heat transfer enhancement because of its ability to induce periodic boundary layer restart mechanism between the fins that has a direct effect on heat transfer enhancement. The effects of the fin geometry on the flow field and heat transfer are studied in three-dimensions using numerical techniques, and the results are then compared with the results from the analytical calculations. The pre-processor GAMBIT is used to create a computational mesh, and the CFD software package FLUENT that is based on the finite volume method is used to produce the numerical results. (Abstract shortened by UMI.)...