A study on the effect of hydrogen enriched intake air on the characteristics of a diesel engine fueled with ethanol blended diesel

This work aims to replace conventional diesel fuel with low and no carbon fuels like ethanol and hydrogen to reduce the harmful emission that causes environmental degra-dation. Pursuant to this objective, this study investigated the performance, combustion, and emission characteristics of the diesel engine operated on dual fuel mode by ethanol -diesel blends with H2 enriched intake air at different engine loads with a constant en-gine speed of 1500 rpm. The results were compared to sole diesel operation with and without H2 enrichment. The ethanol/diesel was blended in v/v ratios of 5, 10, and 15% and tested in a diesel engine along with a 9 lpm H2 flow rate at the intake manifold. The results revealed that 10% ethanol with 9 lpm H2 combination gives the maximum brake thermal efficiency, which is 1% and 4.8% higher than diesel with and without H2 enrichment, respectively. The brake specific fuel consumption of the diesel-ethanol blends with H2 flow increased with increasing ethanol ratio in the blend. When the ethanol ratio increased from 5 to 10%, in-cylinder pressure and heat release rate were increased, whereas HC, CO, and NOx emissions were decreased. At maximum load, the CO and HC emission of 10% ethanol blend with 9 lpm H2 case decreased by about 50% and 28.7% compared to sole diesel. However, NOx emission of the same blend was 11.4% higher than diesel. From the results, the study concludes that 10% ethanol blended diesel with a 9 lpm H2 flow rate at the intake port is the best dual-fuel mode combination that gives the best engine char-acteristics with maximum diesel replacement.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.