Effect of Combustion Chamber Geometry on Performance and Combustion Characteristics of Hydrogen Enriched Diesel Engine

摘要

The in-cylinder air motion in diesel engines generally characterised by swirl, squish and turbulence which have major impact on air-fuel mixing. To achieve controlled combustion, an attempt is made at investigating the effect of change of piston geometry on the combustion & performance characteristics of diesel engine enriched with hydrogen at optimum flow rate on four stroke single cylinder diesel engine. The combustion parameters for diesel engine enriched with hydrogen in hemispherical combustion chamber at 61pm flow rate are increased by 7.72%, 13.48% and 17.26% of Cylinder pressure, Heat release rate & exhaust gas temperature respectively compared to alone diesel operation at rated load and constant speed. The performance characteristics such as brake thermal efficiency is increased by 6.35% and specific fuel consumption is reduced by 33.5% as against neat diesel operation at constant flow rate of hydrogen. This is mainly due to high combustion temperatures which leads to complete burning of fuel and reduction in carbon content with addition of hydrogen. Again it is observed that with re-entrant geometry of the combustion chamber at 61pm flow rate of hydrogen the combustion and performance parameters are further improved significantly compared to hemispherical and toroidal combustion chamber geometries.