Experimental Investigation On The Effects Of Fuel Additives On Gasoline Engine Combustion And Emissions Characteristic

With the increasing number of vehicle and the decreasing oil resource, as well as increasing stringent environmental regulation, the reduction of the fuel consumption and improvement on engine emission become the top priority. Improving of the quality of fuel by using of additives is feasible measure, which does not need to change the structure of internal combustion engine, and has the advantages of flexible, simple and low cost.In this paper, the different volume ratio additives'influences on the economy of different fuels as well as the characteristics of combustion and emission have been investigated employing the knowledge about combustion dynamics and chemical reaction dynamics on the base of the gasoline additives application actuality in engine. Dimethyl Carbonate (DMC), Diisopropyl Ether (DIPE) and Ditert-Butyl Peroxide (DTBP) are selected as gasoline additives to explore the potential and promotable additives by engine tests in different base fuels. In addition, the experiment of E93 ethanol gasoline and pure ethanol has been carried by engine test-bed, and the influences of DTBP on the consumption of 93# ethanol gasoline and pure ethanol fuel and the combustion have been analyzed.When 3% volume fraction was added, DMC and DIPE lead to the fuel consumption rate average increase by 0.85% and 1.6%, respectively; and when 6% volume fraction was added, the corresponding increases are 3.7% and 1.3%. In addition, the cylinder peak pressure points decline, the biggest heat release points delay, and HC emission increase. DMC results in the improvement of the emission of NOx. The addition of 2‰DTBP to the 93# gasoline will knock, and the addition of 1‰DTBP to the 95#and 97# gasoline can effectively reduce the consumption rate of fuel. DTBP can increase the cylinder peak pressure of 95# and 97# gasoline, improve combustion speed in the middle and high load, and improve the emissions of CO, HC, NOx in high load; engine's average rate of fuel consumption increases by 4 percent compared to 93# gasoline when burn ethanol gasoline. When 1‰volume fraction DTBP was added to ethanol gasoline, the rate of fuel consumption decreases by 1.9 percent compared to only using of ethanol. In the whole load conditions, engine's instruction pressure and heat releasing rate have increased. When pure ethanol was used, fuel consumption rate significantly increase in the entire load range, in the whole load condition, peak cylinder pressure ahead slightly, peak cylinder pressure increase, and thermal efficiency has been improved. After the addition of DTBP to pure ethanol, the consumption of fuel decreases, the peak cylinder pressures in three different loads are higher than those in using pure ethanol, and the point of peak pressure comes earlier.