Studies on Exhaust Emissions of Direct Injection Diesel Engine with Different Low Heat Rejection Combustion Chambers Fuelled with Tobacco Seed Oil Biodiesel

Abstract

Experiments were conducted to determine exhaust emissions of direct injection diesel engine with different versions of low heat rejection (LHR) combustion chambers of air gap insulated piston and air gap insulated liner (LHR–2); air gap insulated piston, air gap insulated liner and ceramic coated cylinder head (LHR–3) with different operating conditions [normal temperature and pre-heated temperature] of tobacco seed oil biodiesel with varied injection timing and injector opening pressure. Comparative studies on exhaust emissions were made between different versions of the LHR combustion chamber with biodiesel operation with varied engine parameters. The optimum injection timing was found to be 29o bTDC (before top dead centre) with engine with LHR–2 combustion chamber, while it was 28o bTDC for LHR-3 combustion chamber and 31obTDC for conventional engine (CE). Particulate emissions decreased, while nitrogen oxide levels increased with different versions of the LHR combustion chamber when compared with CE with mineral diesel operation .Advanced injection timing and increase of injector opening pressure reduced exhaust emissions from LHR engine with biodiesel operation.