Thermoelektrische Generatoren (TEG) zur Effizienzsteigerung von modernen Nutzfahrzeugen

Kurzfassung

Fuel consumption and emissions from commercial vehicles account for a large proportion of road transport emissions and without further technical innovation, significant reductions are unlikely. Part of this problem is that about 2/3 of the chemical energy in the fuel of current diesel vehicles is lost in the form of waste heat via the engine coolant and exhaust system. Thermoelectric generators offer a solution with low complexity and a competitive cost-benefit ratio compared to other efficiency technologies. In this research study, a holistic modelling approach that includes all vehicle interactions is used. The objectives of the study are conventional heavy-duty diesel vehicles and natural gas vehicles. In the context of the transformation of the transport sector, the potentials for future powertrains, such as hydrogen combustion engines and fuel cells, are also presented. The holistic approach enables the evaluation of the technology based on fuel and emission reduction as well as payback time for current and future commercial vehicles. The use of a thermoelectric generator appears to be techno-economically advantageous for current and future powertrains. The results are highly dependent on the load point and the application profile of the vehicles. For example, the fuel savings for a current diesel vehicle are in the range of 0.5-1.5% and the payback period is between 1.4 and over 10 years. For current natural gas vehicles, it is 1.8-2.6% and 0.7-2.5 years. The holistic research approach and highly integrated design of the system have enabled power densities of up to 250 W/dm3 for diesel vehicles and up to 570 W/dm3 for natural gas vehicles. These values represent significant increases in the state of the art. The thermoelectric waste heat recovery technology is of interest for vehicle applications with gasoline, diesel, natural gas, hydrogen combustion engines and fuel cells.