Work

Effect of ammonia and diesel fuel injection pressure on combustion characteristics of high-pressure ammonia direct injection marine dual fuel engine

Year: 2026

Type: article

Abstract: Ammonia has emerged as a potential zero-carbon marine fuel due to its compatibility with existing liquefied petroleum gas infrastructure and its role as a hydrogen carrier. However, challenges such as low combustion speed, incomplete combustion, and nitrogen oxide (NOx) emissions hinder its application. This study explores the combustion performance and emission characteristics of ammonia in a marine dual-fuel engine using a 12.5L single-cylinder engine. The experimental setup includes high-pressure ammonia injection and diesel pilot ignition to address ammonia's high self-ignition temperature and low energy density. By varying ammonia and micro-pilot (MP) fuel injection pressures and timings, we evaluate their effects on thermal efficiency, combustion stability, and exhaust emissions. Results indicate that increased ammonia injection pressure enhances efficiency and combustion stability, while optimized MP injection pressure improves atomization and ammonia ignition. However, emissions of NOx and unburned ammonia remain critical issues.

Source: International Journal of Engine Research

DOI: 10.1177/14680874261429814