A study of a thermoelectric generator applied to a diesel engine

Automotive engines have a thermal efficiency of approximately 30%, and the rest is lost as heat in the exhaust and the coolant. Therefore, recycling technology for the waste energy is desirable in order to improve the thermal efficiency of engines. An increase in the thermal efficiency also leads to a reduction in the carbon dioxide emissions. A co-generation system has attracted attention as a promising technology to cope with the stringent emission regulations and the energy depletion. A thermoelectric generator could be suitable for producing electricity from the waste heat; however, its low conversion efficiency must be improved. In addition to improving the efficiency of the thermoelectric generator itself, it is necessary to maximize the heat transfer from the waste heat sources to the thermoelectric generator. With that goal in mind, this study provides valuable information about optimization of the heat transfer, including optimization of the system layout, and about design of the exhaust manifold.