Influence of Injector Opening Pressure on Exhaust Emissions in Insulated Diesel Engine

As the fossil fuel used for internal combustion engine is depleting day by day due to heave demand in transportation sector and in agriculture sector, the emphasis on fuel conservation is increasing at a faster rate. Out of which, the use of the low heat rejection engine or insulated engine is gaining momentum as it has many advantages such as heat release rate is higher, faster rate of combustion, specifically used for low calorific value and high viscosity fuels. There are many variables in compression ignition (CI) engine parameters such as change of injection timing, injection pressure, compression ratio, pre-heating etc., out of which variation of injection pressure is a simple technique to control exhaust emissions of CI engine, as it improves combustion with improved spray characteristics of the fuel. Investigations were carried out to determine exhaust emissions of an engine with low heat rejection (LHR) combustion chamber with air gap insulated piston and air gap insulated liner with neat diesel operation with varied injector opening pressure. The exhaust emissions from diesel engine are particulate matter and oxides of nitrogen. Breathing of these emissions causes health hazards and also they are responsible for greenhouse effect and global warming. Hence the control of these emissions is immediate step and at any cost. Exhaust emissions (particulate emissions and oxides of nitrogen (NOx)) were determined at various values of brake mean effective pressure (BMEP) of the engine. Particulate emissions were measured by AVL Smoke meter, while NOx by Netel Chromatograph NOx analyzer. The exhaust emissions with LHR engine were compared with conventional engine (CE).Particulate emissions and NOx emissions increased with LHR engine. However, these emissions decreased with an increase of injector opening pressure.