Improving Efficiency and Emission Characteristics of a DI Diesel Engine Using Hydrogen-Enriched Juliflora Biodiesel-DEE Blends

Resumen

Investigations were carried on single cylinder, four stroke constant engine speed for varying load conditions direct injection engine fuelled by Juliflora biodiesel along with hydrogen t and Diethyl Ether as an additive at 5% by volume. Hydrogen was sent through intake manifold in varying proportions as 4 lpm, 6 lpm and 8 lpm. Brake thermal Efficiency and Specific fuel consumption as performance and CO, UHC, CO2, NOx and Smoke Opacity as emission characteristics of the engine were observed. While enriching the hydrogen along the JFB20DEE5 varying flow rates such as 4 lpm, 6 lpm and 8 lpm the BTE is increased to 2%, 5.1% and 10 % than the diesel. As the load increases the brake thermal efficiency also increases for biodiesel blends of JFB20 but when hydrogen is added with the blends it is observed that the brake thermal efficiency has been increased by 10% for JFB20DEEH8 than diesel at higher load. Compared to diesel, the percentage of the SFC decreases for increasing the loads for the all the JFB20 blends. Compared to diesel the JFB20 blend give more fuel consumption than diesel and also it continues in the case of the blend when DEE is added. It is noticed that when the JFB20DEE5 is enriched by hydrogen with varying flow rates the BSFC is decreased. It is observed that at full load the BSFC decrease by 4% for the JFB20DEE5H8 blend than pure diesel. When the blend is enriched by hydrogen for the 4 lpm, 6 lpm and 8 lpm, the CO emission is considerably decreased for the half load and full load conditions as 9%, 13% and 17% respectively. The UBHC emissions are decreases when the Diethyl Ether is added to blend it gives 9% HC reduction as the load increases. For the blends JFB20DEE5H4, JFB20DEE5H6 and JFB20DEE5H8, UBHC is decreasing by 9% to 28% at full load than diesel. NOx emissions are high for pure diesel. Increasing load gradually increases the NOx emission for all tested fuels. At the highest hydrogen flow rate 8 lpm (JFB20DEE5H8) the cylinder pressure is notably higher, reflecting more efficient and potentially more powerful combustion. The data specifically highlights that at 100% load, 8 LPM hydrogen flow produces an approximate 10.3% increase in cylinder pressure compared to using diesel fuel. At 100% load, the HRR for JF B20 reaches 32.22 J/oCA, and when adding 5%DEE it increases to35.9J/oCA. For 8 LPM hydrogen is introduced, this value goes up to 41.74 J/oCA-an increase of 3.41 J/oCA or an enhancement by 9%.The high flame speed and energy density of hydrogen improve overall combustion efficiency, resulting in higher heat release and pressure.