DESIGN AND ANALYSIS OF EXHAUST GAS HEAT EXCHANGER

Ideal heat exchangers recover as much heat as possible from an engine exhaust at the cost of an acceptable pressure drop. They provide primary heat for a thermoelectric generator, engine intake air pre-heating and airconditioning and their capacity and efficiency is dependent on the material, shape, and type of the heat exchanger. Four different exhaust heat exchangers were designed within the same shell, and their computational fluid dynamics (CFD) models were developed to compare heat transfer and pressure drop in typical driving cycles for a vehicle with a 1.2 L gasoline engine. And two different materials (carbon steel and AISI4140) were applied to shell. Both the materials are best suited for manufacturing of heat exchanger, with reliable properties. These are the engineering materials that are helpful and playing a vital role in extraction of maximum heat from the exhaust of the engine. The result showed that the serial plate structure enhanced heat transfer by 7 baffles and transferred the maximum heat of166.358kw and maximum pressure drop of 9.2712kpa in a suburban driving cycle. Modeling of shell and all the structures were done in PTC-CREO and simulations were done in ansys FLUENT 15.0.