Experimental investigation on N 2 O emission characteristics of ammonia-diesel dual-fuel engines

作者：Yi Liu, Kai‐Yuan Cai, Yunliang Qi, Qingchu Chen, Hu Chen, Zhi Wang · 发表于：International Journal of Engine Research · 年份：2025 · DOI：10.1177/14680874241307920 · 被引用次数：8 · 研究领域：Catalytic Processes in Materials Science、Advanced Combustion Engine Technologies、Vehicle emissions and performance

Blending ammonia in combustion is an effective approach to reducing carbon emission for diesel engines, but the combustion of ammonia may result in the generation of elevated concentrations of nitrous oxide (N 2 O), potentially contributing to a new source of greenhouse gas emissions. This study investigates the impact of engine load, diesel double injection strategy, and the ammonia energy ratio (AER) on N 2 O emission in ammonia-diesel dual-fuel combustion mode. The results show that N 2 O emission is increased with blending ammonia compared to pure diesel combustion, while as the load increases, the higher in-cylinder combustion temperature leads to a decrease in N 2 O emission. In the ammonia-diesel dual-fuel combustion mode, diesel double injection strategy is conducive to the reduction in N 2 O emission compared to single injection strategy. As the pre-injection timing is delayed, N 2 O emission first decreases and then increases, reaching a minimum near −40 °CA ATDC. The postponed main-injection timing leads to the decreased in-cylinder combustion temperature, deteriorating N 2 O emission. In the engine with a compression ratio (CR) of 18, when AER is in the range of 20% to 65%, the volume fraction of N 2 O emission remains around 20 × 10 −6 . However, under the condition of AER = 80%, low chemical reactivity of ammonia causes the substantially increased N 2 O emission. By increasing CR to 21 and adopting optimal injection strategy, combustion in activated thermal atmo...