D. Srikanth

Effect of Spark Ignition Timing on Copper Coated Spark Ignition Engine With Alcohol Blended Gasoline With Catalytic Converter

This paper reports performance evaluation of four–stroke, single–cylinder, water cooled, variable compression ratio (3–9), variable speed (2200–3000 rpm) spark ignition engine with brake power of 2.2 kW at a speed of 3000 rpm with copper coated combustion chamber (CCE) [copper-(thickness, 300 μ) was coated on piston crown, inner side of liner and cylinder head] with alcohol blended gasoline [20% methanol with 80% gasoline; 20% of ethanol with 80% of gasoline by volume) with varied spark ignition timing provided with catalytic converter with sponge iron as catalyst along with air injection and compared with engine with conventional combustion chamber (CE) with gasoline operation. Performance parameters and exhaust emissions (CO and UBHC) were evaluated at full load operation of the engine. Aldehydes (formaldehyde and acetaldehyde) were measured by wet method of 2,4, dinitrophenyle method at full load operation of the engine. Alcohol blended gasoline operation improved performance and reduced CO and UBHC emissions when compared with gasoline operation with both versions of the combustion chamber. At recommended and injection timing, CCE with test fuels improved performance and reduced pollution levels, when compared with CE. Catalytic converter with sponge iron as catalyst along with air injection significantly reduced pollutants with test fuels.Copyright

Experimental Investigations on DI Diesel Engine With Low Heat Rejection Combustion Chamber With Carbureted Ethanol and Crude Jatropha Oil

It has been found that the vegetable oils and alcohols (ethanol and methanol) are promising substitute fuels for diesel fuel, because they are renewable in nature. However drawbacks associated with crude vegetable oil (high viscosity and low volatility) and ethanol (low cetane number and low energy content) which cause combustion problems in CI engines, call for engine with hot combustion chamber. Investigations were carried out on single–cylinder, four–stroke, water cooled, 3.68 kW direct injection diesel engine at a speed of 1500 rpm to evaluate the performance of a engine with medium grade low heat rejection (LHR) combustion chamber. It consisted of an air gap insulated piston and an air gap insulated liner fuelled with crude jatropha oil and carbureted ethanol with varied injection timing and injector opening pressure. Carbureted ethanol was inducted into the engine through a variable jet carburetor. This carburetor was installed at the inlet manifold of the engine and ethanol was inducted at different percentages of crude vegetable oil at full load operation on mass basis. Aldehydes (measured by dinitrophenyl hydrazine method), particulate emissions and oxides of nitrogen were measured at full load operation of the engine. With maximum induction of ethanol, engine with LHR combustion chamber showed improved performance over conventional engine at 27°bTDC and optimized injection timing.Copyright

Experimental Investigations on DI Diesel Engine With Low Heat Rejection Combustion Chamber With Waste Fried Vegetable Oil and its Biodiesel

Biodiesels derived from vegetable oils present a very promising alternative fuels for diesel fuel, since they have numerous advantages compared to fossil fuels. However crude vegetable oil and biodiesel have high viscosity and low volatility causing combustion problems in CI engines, call for engine with hot combustion chamber. Investigations were carried out on single–cylinder, four–stroke, water cooled, 3.68 kW direct injection diesel engine at a speed of 1500 rpm to evaluate the performance of a engine with low heat rejection (LHR) combustion chamber. It consisted of an air gap (3 mm) insulated piston with superni (an alloy of nickel) crown and an air gap (3 mm) insulated liner with superni insert and ceramic coated cylinder head fuelled with different operating conditions (normal temperature and preheated temperature) of waste fried vegetable oil and its biodiesel with varied injection timing and injector opening pressure. Engine with LHR combustion chamber with biodiesel showed improved performance over conventional engine (CE) at 27° bTDC and at optimum injection timing. Biodiesel showed improved performance over crude vegetable oil with engine with both versions of the combustion chamber. Preheated test fuels and increase of injection pressure showed reduction of pollution levels and marginally improved performance over normal test fuels.Copyright