Effect Of Coal-based Synthetic Diesel/Butanol Blend Fuel On Combustion And Emissions Of Compression Ignition Engines

The energy crisis and environmental pollution are two major challenges facing human society.The rapid development of the automotive industry is also restricted by emission regulations and fuel consumption regulations.Therefore,it is particularly important to apply clean alternative fuels to achieve efficient and clean combustion of internal combustion engines.This article relies on the Jilin Provincial Natural Science Foundation-research on high-efficiency clean combustion technology of internal combustion engines based on coal-based synthetic diesel,for the combustion boundary of coal-based synthetic diesel(CTL)and oxygen-containing fuel n-butanol in blending and dual fuel injection Optimization of the conditions,trying to find the best combustion boundary condition collaborative control strategy suitable for CTL and its mixed fuel with n-butanol,and explore its improvement potential for NOx and particulate emissions.In this study,through the self-reformed supercharged single-cylinder compression ignition engine,an experimental research measurement and control platform was established,and a simulated supercharged intercooling system,an EGR control system,and a dual fuel injection control system were developed to achieve the boundary conditions of engine intake and combustion in the cylinder Actively control and adjust the combustion and emission characteristics of different proportions of CTL / n-butanol blended fuel under different EGR,fuel injection parameters and other combustion boundaries.Research indicates:1.Combustion of n-butanol / CTL mixed fuel is beneficial to increase the maximum pressure and heat release rate in the cylinder,thereby improving the thermal efficiency of the engine,but the pressure increase rate is also significantly increased.With the increase of the n-butanol blending ratio,the stagnation period of the mixed fuel is extended,the smoke and CO emissions are improved,but the NOx and HC emissions have increased.The blending of n-butanol fuel has a very positive effect on improving the number of particles,and the improvement effect is better under heavy load conditions.Compared with the CTL under heavy load,the D10 fuel has a total particle number concentration,nuclear particle number concentration,accumulation The reduction of the number and concentration of particles in the state reached: 89.4%,75.5%,92.8%.In addition,a particulate trap is used for n-butanol / CTL mixed fuel,and the total particulate trapping efficiency is above 90%.2.Proper fuel injection in advance and increased injection pressure are conducive to the increase of the highest pressure in the cylinder and have a positive impact on improving the thermal efficiency of the engine.Although the NOx emission has been improved,it has a good suppression effect on particulate emission.The introduction of EGR can significantly reduce NOx emissions when the smoke increase is not obvious,and the n-butanol / CTL mixed fuel has better EGR tolerance than the single CTL fuel.3.The optimization results of EGR co-injection timing for n-butanol / CTL mixed fuel show that the best NOx-PM emission point is between 20-30% EGR rate and the injection timing is 5 °-7 ° CA BTDC Compared with the CTL reference point,the NOx emission of the D10 fuel obtained by this study is 26.9% lower than that of the CTL reference point,and the particle number concentration is reduced by 44%.4.The regularity of the n-butanol / CTL dual fuel injection engine with EGR and fuel injection timing is roughly the same as the blending mode.Increasing the n-butanol injection ratio can reduce particulate emissions and improve its resistance to EGR.But it will cause a significant increase in HC and CO emissions.The optimal NOx-PM optimization point of the 30% ratio of n-butanol and CTL dual fuel injection engines is 37% lower than that of a single CTL optimization benchmark,and the particle number concentration is reduced by 51%.5.Comparative analysis of the emission of n-butanol / CTL blending and dual fuel injection,it can be found that the NOx emission in the dual fuel injection mode is low,and under the condition of large EGR,the particle number concentration in the dual fuel injection mode It is also lower,but the HC and CO emissions in this mode are significantly higher than the blending mode.