Robust Emission Management Strategy to Meet Real-World Emission Requirements for HD Diesel Engines

摘要

Heavy-duty diesel engines are used in different application areas, like long-haul, city distribution, dump truck and building and construction industry. For these wide variety of areas, the engine performance needs to comply with the real-world legislation limits and should simultaneously have a low fuel consumption and good drivability. Meeting these requirements takes substantial development and calibration effort, where an optimal fuel consumption for each application is not always met in practice. TNO's Integrated Emission Management (IEM) strategy, is able to deal with these variations in operating conditions, while meeting legislation limits and obtaining on-line cost optimization. Based on the actual state of the engine and aftertreatment, optimal air-path setpoints are computed, which balances EGR and SCR usage. Due to IEM's adaptation characteristics based on the actual state of engine and aftertreatment system, the strategy is robust for varying conditions during real-world operation. This is especially of interest, since real-world emissions become increasingly important: in-use compliance, including Not-To-Exceed (NTE) areas, challenging On-Board-Diagnostics requirements and In-Use Performance Ratio (IUPR) monitoring. The main contribution of this work is to demonstrate the robustness of IEM on a variety of real-world cycles by means of a simulation study. Whereas previous publications focus on demonstration of the IEM strategy on Type Approval cycles, this work can be seen as an extension, which also addresses In-Service Conformity (ISC). This paper discusses in detail the performance and robustness of the IEM strategy at these cycles compared with a state-of-the-art Euro-VI engine control strategy (baseline). Consequent improvements are obtained among the different cycles. Fuel consumption and fluid cost are reduced up to 2% and 1.7%, respectively, compared to this baseline strategy.