Improved Performance and Reduced Emissions in a D. I. Engine by Fuel Additives 2001-01-2504

Diesel Engineers are major sources of prime movers, which are widely used for small and large-scale power generation and transportation purposes. These engines are widely used owing to its high power output and general thermal efficiency. Inspite of these benefits diesel engines cause serious environmental and human discomforts on global scale. The important pollutants from a diesel engine are NO_x , HC and particulate matter. These particulates are inhalable, capable of travelling deep into lungs and causes diseases. As a result of this governments and health organizations have tightened the standards for pollutants from diesel engine. Hence it has becomes important that these particulate matters have to be reduced or eliminated from the exhaust f diesel engine.

This project aims to reduce the particulate emission in the diesel engine exhaust and to improve the performance of the engine. A literature survey was conducted revealed that using fuel additives, which oxygenate the fuel and reduces the emissions, can reduce the particulate emission. Additives like Ethylene glycol dimethyl ether, Diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, Butyl ether, Aliphatic alcohol, Aromatic alcohol and Glycol ethers were used by various researchers in this field, as fuel additives. Encouraging results were obtained and some of them are reported in this project. In this oxygenates, ethers behave better than alcohol's.

Hence for this present work some of the ethers were selected which were not much tried and detail were not much known. Three additives were selected for the fuel. Diethylene glycol mono butyl ether, Diethylene glycol mono butyl ether, Diethylene glycol mono-n-hexyl ether and Dibutyl ether are the additives selected. A single cylinder direct injection diesel engine (Greaves cotton engine) was selected for conducting the tests. These oxygenates were added in different quantities to the selected base fuel, diesel. Load tests and speed tests were conducted first with the sole fuel (diesel) and then with the smoke emissions were deduced to a very great extent, the maximum reduction was obtained while using 4ml of Diethylene glycol mono-n-hexyl ether. The smoke level is reduced from 70HSU to 29HSU, the particulate matter is reduced from 2.801 g/hr to 1.512 g/hr and the smoke conversion efficiency is found out as 58.57% at full load. A slight decrease in fuel consumption and about 1 to 2 % increase in brake thermal efficiency was found out from the experiment conducted, for various loads and speeds which shows obviously an improvement in the performance. The other two additives also shows the same trend except that these values slightly differ indicating that Dibutyl ether comes as second good additive and Diethylene glycol mono butyl ether as third good additive. Detailed results are reported in the results and discussions chapter and conclusions at the end.