Development of a Centralized Vehicle Integration Control Unit for Enhanced Fail-Operational

초록

The co-combustion of ammonia and gasoline is one of the effective measures to improve energy efficiency and reduce carbon emissions in spark-ignition engines. However, it requires high-energy ignition to enhance combustion performance. Passive pre-chamber can improve the combustion characteristics of ammonia–gasoline mixtures with minimal modifications to the engine. Nevertheless, current research on this topic remains incomplete, particularly lacking comprehensive performance assessments of passive pre-chamber turbulent jet ignition (TJI) combined with ammonia addition in four-cylinder gasoline engines. This study focuses on the effects of the ammonia energy ratio (ER) and excess air ratio (λ) on the combustion characteristics, engine performance, and emission characteristics of ammonia–gasoline dual-fuel under the TJI mode. The results indicate that TJI combined with spark timing adjustment can ensure an optimal combustion phase and achieve stable combustion within a λ range of 1.0–1.5 and an ammonia ER of 0–47%. The λ corresponding to the optimal indicated thermal efficiency (ITE) is influenced by the ammonia ER. Two fuel economy regions are identified: one with a low ER and high λ, and the other with a high ER and low λ. Replacing gasoline with ammonia, in combination with TJI, can reduce CO₂ emissions by at least 30% while maintaining low CO emissions. Additionally, under equivalent lean-burn conditions, it reduces NOₓ emissions by approximately 28.9% compared to pure gasoline operation. However, a downside is an increase of about 5.6% in brake-specific fuel consumption (BSFC) compared to gasoline lean-burn conditions (λ = 1.5), and a significant increase in unburned ammonia emissions.

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