Klaus Hadl’s research while affiliated with AVL LIST GMBH and other places

The California Air Resources Board and US Environmental Protection Agency have defined their new ultra-low NOx standards for heavy-duty diesel engines (HDDE) over the last two years. In parallel, AVL has continued its research on how to meet these new limits and to address the continuing challenge of cold start emissions from HDDE, including incorporating • Advanced thermal management strategies to accelerate exhaust aftertreatment system (EAS) warm-up • Close-coupled selective catalytic reduction (ccSCR) system upstream of the current Euro VI or EPA 2013 EAS This paper will continue from the presentation at the 2019 CLEERS Workshop and present further developments in the research program including experimental results. These results include the following: • Measured effects of thermal management strategies on EAS warm-up • Test results using the ccSCR and “underfloor” SCR in combination • Strategies for successful ultra-low NOx compliance • Interactions between ccSCR system and on-board diagnostics (OBD) requirements AVL recommendations and next steps will also be discussed. [See https://cleers.org/cleers-workshops/workshop-abstracts/?entry_id=3199]

In April 2019, the California Air Resources Board (CARB) released its white paper on the ultra-low NOx standard for heavy-duty diesel engines (HDDE)[1]. AVL has been conducting research on how to meet these new limits and to address the continuing challenge of cold start emissions from HDDE, including incorporating • Advanced thermal management strategies to accelerate exhaust aftertreatment system (EAS) warm-up • Close-coupled selective catalytic reduction (ccSCR) system upstream of the current Euro VI or EPA 2013 EAS To date, the most of the work done has been in simulation, with the intent of evaluating control strategies. This paper will describe the following results: • Effect of thermal management strategies on EAS warm-up • Control strategy for ultra-low NOx incorporating ccSCR • Interactions between ccSCR system and on-board diagnostics (OBD) requirements The interaction between NOx control and reduced fuel consumption or CO2 emissions will be discussed. AVL recommendations and next steps will also be discussed. [See https://cleers.org/cleers-workshops/workshop-presentations/entry/2100/] 1. California Air Resources Board, “California Air Resources Board Staff Current Assessment of the Technical Feasibility of Lower NOx Standards and Associated Test Procedures for 2022 and Subsequent Model Year Medium-Duty and Heavy-Duty Diesel Engines.” California Air Resources Board Report No, 2019.

div class="section abstract"> Most stringent emission legislations have been implemented in all major markets to improve air quality across the past years. This effects the product cost of the vehicles which is considered being critical and needs to be minimized. India suffers from bad air quality and countermeasures have been defined. One being the implementation of similar emission standards than EU VI. By doing so, India takes a large step going from the currently effective BS IV directly to BS VI. Emission reduction is currently mainly handled by the usage of EGR, thus no engine aftertreatment system has been applied. BS VI will require an aftertreatment (EAS) concept with several catalysts and corresponding control system. India is a very cost sensitive market and a carry over of solutions from the EU needs to be evaluated carefully and new approaches need to be found. While the enforcement of BS VI Phase I does not dictate any in-service conformity factors yet, phase II (planned implementation 2023) possibly enforces a conformity factor of 1,5 for pollutants as well as more stringent OBD requirements. In this paper different engine + EAS concepts will be presented and evaluated in terms of emission compliance and product cost. One interesting technology route for N3 applications could be a non EGR approach. In order to master the challenges for that approach AVL´s unique controls and diagnosis concept with focus on emission robustness will be presented and explained. </div