Experimental Investigation of Heat Transfer Across a Thermoelectric Generator for Waste Heat Recovery From Automobile Exhaust

The study investigates the temperature gradients achieved across a thermoelectric generator by using the exhaust gases from a vehicle as a heat source and the radiator coolant as the cold sink. Various heat transfer enhancement features are employed in order to achieve as high a temperature gradient as possible. Effect of flow Reynolds numbers and inlet temperatures are examined to create a body of data predicting total power output from the TEG. Data is normalized against results from baseline heat exchanger designs investigated in the past. The experiments are carried out at 1/5th scale of the previously examined geometry. Impingement geometry is employed on the coolant side to enhance heat transfer. The experimental test sections are fabricated using metal 3D printing. Water is used instead of radiator coolant and heated air is used for exhaust gases. The results from the experiments provide valuable data which can be used for system level optimization.