Effect of negative valve overlap in a heavy-duty methanol-diesel dual-fuel engine: A pathway to improve efficiency

Methanol (MeOH) is a promising low-carbon liquid fuel to provide global energy security with potential achieve net-zero greenhouse gas emissions in transport sector. However, its utilization diesel engines at high MeOH substitution ratios (MSR) suffers from misfire or pressure rise rates owing distinct physio-chemical properties. This issue addressed the present study by adopting negative-valve overlap (NVO) and hot residual gases previous cycle. Experiments are performed single-cylinder heavy-duty CI engine for constant MSR (90% based) an speed of 1500 rpm. The aim investigate effects 1) NVO period, 2) charge-air temperature (Tair), 3) lambda (λMeOH) on MeOH-diesel dual-fuel (DF) combustion mode, 4) demonstrate implications yielding net-indicated efficiency (ηind) together low pollutant wide range operating loads (40–90%). results show that cycle enhance reactivity fresh MeOH-air mixture inducing slow oxidation processes before TDCf. pre-flame disruptive oscillatory nature, wherein Tair λMeOH can be used control these their induced enhancing capability. It noticed main have direct correlation between them. Based strategy, mode produced average ηind approx. 53% accompanied very NOx emission 1.1 g/kWh Additionally, phasing (CA50) maintained ∼ 2 oCA aTDC, while stability remains (COVIMEP 3.5%).