48V EGR Pump System Development and Fuel Benefit Evaluation

Upcoming global emission regulations include considerable reduction in emission of nitrogen oxides (NOx) and greenhouse gases (GHGs) for vehicles with heavy-duty (HD) diesel application. These regulations will phase between 2024 and 2030 in the United States and the European Union. CARB Regulations include up to 90% reduction in NOx levels along with ∼25% reduction in CO2. One of the primary technologies used to reduce engine out NOx emission is the use of cooled exhaust gas recirculation (EGR). Research studies carried out across multiple domains by engine/vehicle original equipment manufacturers (OEMs) and others have identified air handling as one of the technologies to help meet next-generation regulations (Joshi, 2020; Dreisbach et al. 2021). This includes more efficient turbomachinery which helps improve engine efficiency and thus reduce GHGs. This has an adverse effect on driving EGR which affects engine out NOx. In this study, the development and performance impact of the EGR pump is investigated, which allows improved engine fuel efficiency without the corresponding penalty to engine out NOx. Computational fluid dynamics (CFD) is used to optimize the EGR pump design, which leads to reduction in fluid-borne noise of the pump, which is then evaluated for fuel benefits using a calibrated GT-POWER engine model.