Effect of Compression Ratio on Combustion, Performance and Emission Characteristics of DI Diesel Engine with Orange Oil Methyl Ester

Abstract

Biodiesel was used as an effective alternative to the fossil fuel, as it was non-toxic, renewable and biodegradable resource. Engine parameters like compression ratio, injection timing and injection pressure play a key role in the combustion of biodiesel. This research work presents the effect of compression ratio on the combustion, performance and emission characteristics of 80% diesel blended with 20% orange oil methyl ester (20OME) in diesel engine. Experiments were conducted on a single-cylinder direct injection (DI) diesel engine with compression ratios of 17:1 and 18:1. Diesel exhibited higher Brake Thermal Efficiency (BTE) than 20OME at both compression ratios. At all loads, an increased Brake Specific Energy Consumption (BSEC) was observed for 20OME in both compression ratios. Due to the presence of more oxygen content in the prepared biodiesel sample, 20OME showed higher heat release rate than diesel at compression ratio 18. Consequently, 20OME showed higher rate of pressure than diesel at CR 18. 20OME showed higher Exhaust Gas Temperature (EGT) than diesel at all loads. At CR 18, both diesel and 20OME showed similar trend of HC and CO emissions whereas in CR 17, diesel exhibited lower CO and HC emissions than 20OME. At low loads, 20OME showed lower NOx emission than diesel in compression ratio 17 whereas in CR 18, both fuels exhibited higher NOx emission at all loads. Lower smoke emission was observed with 20OME than diesel at both compression ratios.