Comparative study on the combustion and emissions of dual-fuel common rail engines fueled with diesel/methanol, diesel/ethanol, and diesel/n-butanol

In this article, a comparative study on the effects of energy substitution ratio (ESR) on the combustion characteristics and performance of a dual fuel engine fueled with diesel/methanol, diesel/ethanol, and diesel/n-butanol was conducted experimentally. The experiments were conducted at a fixed speed of 1600 rpm and medium load with a brake mean effective pressure of 0.921 MPa. Five ESRs namely 0% (pure diesel), 10%, 20%, 30%, and 40% were conducted. The experimental results indicated that premixed combustion of diesel was retarded and enhanced, while the diffusion combustion of diesel was accelerated and advanced after these three alcohol enrichments. The ignition delay was prolonged, whereas the combustion duration was shortened for a dual fuel engine fueled with diesel/alcohols. In addition, methanol is the most beneficial in term of prolonging ignition delay and shortening combustion duration for the specific ESR. As the ESR increased from 0% to 40%, the BTE consistently increased from 41.6% to 42.3% and 42.5% for engines fueled with diesel/methanol and diesel/ ethanol, respectively. However, the BTE of diesel/n-butanol engine decreased from 41.6% to 41.1% as ESR increased from 0% to 40%. All three alcohol enrichments decreased the particle concentration in diesel engine with the increase in ESR. The higher the ESR was, the lower the NOx emissions of the diesel/methanol engine and the higher the NOx emissions of the diesel/n-butanol engine.

Automated summary

A comparative study on the effects of energy substitution ratio (ESR) on the combustion characteristics and performance of a dual fuel engine fueled with diesel/alcohols was conducted. Premixed combustion of diesel was influenced by alcohol enrichment, affecting ignition delay and combustion duration. Methanol was found to be most beneficial in prolonging ignition delay and shortening combustion duration. Energy substitution ratio also affected brake thermal efficiency (BTE) and NOx emissions differently for different alcohol types.