Performance and Emissions Analysis of a Hydrogen-Powered Heavy-Duty High Compression Ratio SI Engine Across Various Loads and Speed at Ultra-Lean Condition

<div class="section abstract"><div class="htmlview paragraph">With the global shift towards sustainable and low-emission transportation, hydrogen-fueled engines stand out as a promising alternative to traditional fossil fuels, offering significant potential to reduce greenhouse gas emissions. This study provides a comprehensive evaluation of the performance and emissions characteristics of a hydrogen-powered heavy-duty compression ignition engine, which has been modified to operate as a Spark Ignition (SI) engine with a high compression ratio of 17:1. The evaluation was conducted across various speeds, loads, and spark timings under ultra-lean combustion conditions. The analysis utilized a modified 6-cylinder, 13-liter Volvo D13 diesel engine, configured to operate in single-cylinder mode with the addition of a spark plug for SI operation. The study examined key performance metrics, including brake thermal efficiency (BTE), power output, and specific fuel consumption, under the selected operating conditions. Emissions profiles for nitrogen oxides (NOx), carbon dioxide (CO<sub>2</sub>), and unburned hydrogen (uH₂) were also assessed to understand the environmental impact. The results demonstrated that hydrogen operation can significantly improve thermal efficiency while maintaining adequate power output across various operating conditions. Optimal performance and reduced NOx emissions were observed within specific lambda ranges, underscoring the potential of fine-tuning the air-fuel mixture to enhance both efficiency and emissions. Notably, NOx emissions were found to be negligible under most operating conditions. This study offers critical insights into the viability of hydrogen as a sustainable fuel for heavy-duty engines, paving the way for greener and more efficient transportation solutions. The findings highlight the importance of precise control over engine parameters to maximize the benefits of hydrogen combustion, thereby driving further advancements in hydrogen engine technology.</div></div>