Calibration strategies to overcome the Challenges for Naturally Aspirated Off-Highway Engines for Trem-V emissions

The transition to Trem V emission norms presents significant challenges for naturally aspirated (NA) off-highway engines. Off-highway applications like construction and agriculture segments require high load variability and extended duty cycles with increased BMEP resulting in high PM emissions, and increased exhaust temperatures with lower lambda levels. Given the cost-competitive nature of the segment, it also requires designing leaner intake and exhaust system. To overcome above mentioned challenges, holistic calibration strategies need to be adapted during development phase. To meet Trem V emission norms, solutions like advanced combustion, high-pressure fuel injection, EGR (exhaust gas recirculation), and optimized calibration had to be explored in meeting Trem V emission norms with aftertreatment systems like Diesel Particulate Filters and Diesel oxidation catalysts. Implementation of aftertreatment systems for Trem-V introduces this segment with pre-dominantly with naturally aspirated engines the challenges associated to soot accumulation and thermal management. This paper attempts to examine, the key technical challenges coming from the market towards use of large implements and heavy soil with NA engine demanding high BMEP and challenges associated to operating lambda, smoke emissions and high exhaust gas temperature under different use cases. The research identifies the strategies, such as optimized air-fuel management, optimal specific soot load adaptation and multistage thermal control, to enhance system safety and reliability. Ultimately, the paper provides a strategic roadmap for industry stakeholders to achieve Trem V emissions while ensuring durability, efficiency, and economic viability in off-highway applications.