Mechanical engineering advantages of a dual fuel diesel engine powered by diesel and aqueous ammonia blends

Abstract

With the assistance of Diesel-RK software, the volumetric replacement of aqueous ammonia (NH4OH) with original diesel is being investigated in a dual-fuel diesel engine. Three volumetric percentages of ammonia solution are used along with diesel according to the scenario: (40% NH4OH + 60% Diesel), (50% NH4OH + 50% diesel), and (60% NH4OH + 40% diesel). The numerical analysis is based on a multizone combustion model. In the zone-based approach, the governing equations for each zone are solved as open systems. Comparing diesel fuel with ammonia solutions, the results show that adding ammonia solutions decreases combustion pressure and heat release and increases Sauter diameter and ignition delay. Generally, the use of aqueous ammonia drops engine performance regardless of the percentage of NH4OH used. Since 40%, 50%, and 60% of NH4OH have lower heating values than diesel, BSFC is reduced by 7.15, 10.4%, and 15.38%, respectively. Since the addition of ammonia reduces combustion temperature significantly, a noticeable reduction in NOx emissions is achieved, reaching up to 61.75% in the case of 60% NH4OH. The results highlighted a remarkable reduction in soot emissions (43.4% for 40% NH4OH, 51.04% for 50% NH4OH, and 49% for 60% NH4OH) because the diesel was replaced with no carbon fuel, hence the engine produced less smoke compared to with the baseline case (pure diesel).