Investigation of temperature distribution performances of three different heat exchanger models for exhaust gas waste heat energy recovery system used with thermoelectric generator in gasoline engines

Abstract

In this study, examination of the temperature distribution for three different heat exchanger models for exhaust gas waste heat recovery systems to be used in internal combustion motorcycle engines has been made. Simulations of the models have been made by means of ANSYS Workbench Fluent software and comparative results have been put forward. It has been taken into consideration that the selected heat exchanger models have generable geometries. Model no. 1 is inclined to the outlet from the inlet by 5o, model no. 2 has three steps each of which has a gradient of 20o, and model no. 3 has a fixed section width which is parallel to exhaust gas transfer. Moreover, in model no. 3, a heat sink has been placed into the exhaust gas. On cold surfaces, the highest and the lowest temperatures have been measured respectively as 337.937K and 329.465K in model no. 1, as 342.875K and 329.639K in model no. 2, and as 363.897K and 354.995K in model no. 3. The difference between the lowest and the highest temperatures is observed as in models no. 2 and 3. With relation to the temperature distributions on hot surfaces of TEGs, the lowest and the highest temperatures are respectively as 508.631 K and 402.742 K in model no. 1, as 510.092 K and 409.632 K in model no. 2, and as 536.595 K and 510.633 K in model no. 3 It has been observed that the lowest difference of temperature occurred in model no. 3. When the results are examined, it is seen that the best temperature difference and the highest temperature value have been achieved in model no. 3.