Optimal Control of Diesel Engines with Waste Heat Recovery System

Abstract

This study presents an integrated energy and emission management strategy for a Euro-VI diesel engine with Waste Heat Recovery (WHR) system. This Integrated Powertrain Control (IPC) strategy optimizes the CO2-NOx trade-off by minimizing the operational costs associated with fuel and AdBlue consumption, while satisfying tailpipe emission constraints. The main contribution of this work is that the optimal solution is determined numerically for a given cycle and is compared with a real-time implementable strategy. Also, the WHR dynamics are explicitly included in the control design. In a simulation study, the potential of this IPC strategy is demonstrated over the World Harmonized Transient Cycle. It is shown that the real-time strategy can be applied with negligible loss of optimality. Using IPC, an additional 3.5 % CO2 reduction is achieved, while complying with the NOx emission limit, when compared to a baseline strategy. © Springer International Publishing Switzerland 2014.