Experimental Research And Numerical Simulation On The Performance Of High-Speed Diesel Engine Fuelled With Emulsified Oil

Emulsified oil technology has a long-term social significance in energy conservation and environmental protection.In order to investigate the characteristics of fuel economy, emission and stability, the emulsified diesel fuels, with different water content were prepared through selecting appropriate compound-surfactants on the basis of the HLB (hydrophilic and lipophilic balance) value and the specific emulsification technology. The influence factors on their stability and the mechanism of saving energy and reducing pollutants were also analyzed.Comparative tests between various emulsified diesel fuels and pure diesel were operated on a single-cylinder135type diesel engine for the sake of investigation of the combustion and emission characteristics. Besides, with the employment of CATIA, the three dimensional model of the diesel engine was established, and CFD model was created based on the CAD model. The impact of various water content ratios on the combustion and emission characteristics of the diesel engine were simulated and analyzed by using CFD software of AVL FIRE. In addition, by the methods of contrastive research, the combustion and spray characteristics of emulsified diesel were analyzed.Experimental and simulation results indicate that the emulsified diesel fuels were successfully used in high speed diesel engine with significant reduction of NOx and SOOT emissions and specific fuel consumption. As the water content increases, the ignition delay increases and in-cylinder mean pressures and mean temperatures are lower. The emulsified diesel fuels stabilization time are prolonged after adding emulsion stabilizer such as sodium carboxymethyl cellulose.Optimum water content ratio is10%for this engine after balancing experimental and simulation results as well as considering fuel-saving and emissions.