Engine Thermodynamic Design, Optimization, Test & Analysis of Daimler SuperTruck2 Program Towards 55% BTE Target
2022-01-0504
03/29/2022
- Event
- Content
- Daimler's effort toward demonstration of 55% brake thermal efficiency for the US Department of Energy SuperTruck2 program relied on a holistic approach to optimization of the Daimler heavy-duty 12.8L diesel engine. Core technical approaches used in this effort include efficient two-stage turbocharging with intercooling, valve timing optimization, improved combustion system design, friction and parasitics reduction through optimized lubrication system, and in-cylinder heat transfer reduction. These measures in combination provided an anticipated engine efficiency of over 50% BTE before application of an additional waste heat recovery system. Utilization of high-fidelity simulations from 1D physical model simulation studies and CFD/FEA framework allowed for optimization of the engine pumping loop and heat transfer reduction efforts. Test bench data provides high-level overview of combustion improvement, friction & parasitics reduction, improvement in in-cylinder heat transfer reduction through application of Thermal Barrier Coating (TBC) and overall system level improvements compared to baseline engine to achieve the greater than 50% BTE engine-only target. Furthermore, final push to 55% BTE required integrated WHR systems. Integration of systems from early efforts on refrigerant based WHR in the SuperTruck2 program along with a new approach using phase change cooling (PCC) WHR are presented. The combined engine and WHR efforts show the path to achieve 55% BTE.
- Citation
- Bashir, M., "Engine Thermodynamic Design, Optimization, Test & Analysis of Daimler SuperTruck2 Program Towards 55% BTE Target," SAE Technical Paper 2022-01-0504, 2022, .