Method for designing waste heat recovery systems (WHRS) in vehicles considering optimal control

Designing a waste heat recovery system (WHRS) for a vehicle to maximize fuel economy is challenging. Interactions with vehicle subsystems, transient boundary conditions, major influence of the operating strategy on the performance and the complexity of the optimization problem must be considered. TLK-Thermo GmbH and the Institute of Thermodynamics at the TU Braunschweig develop a method and the software tool chain MoBA-Lab for the analyzation and optimization of complex thermal systems: 1. Sensitivity analyzes to quantify the influence of system parameters on the system dynamics and the energy efficiency of the system. 2. Operating strategies for maximum energy efficiency. 3. Model-based control to ensure the best possible application of the previously determined operation. By means of the developed method, a design concept of a waste heat recovery system for an omnibus is developed and tested in virtual test drives. The simulated fuel economy leads from 5.8 % for the World Harmonized Vehicle Cycle (WHVC) to 8.1 % for a typical drive from Hanover to Munich.