Research On Synergetic Technology Scheme For Energy Saving And Emission Reduction Of Natural Gas Engine

With the rapid development of the automobile industry,the proportion of the fossil fuel demand for vehicle fuel increases year by year.Promoting the optimization of energy consumption structure and developing clean alternative fuels has become an important means to solve the energy crisis and enviro nmental pollution.Natural gas,as a kind of abundant and clean and enviro nmental-friendly energy,has been widely used as an alternative fuel for automobile engines.However,natural gas,as a fuel for automobile engines,has disadvantages such as low calorific value and slow combustion speed.Therefore,it is necessary to optimize the control strategy parameters of natural gas engines.In this paper,the effects of increasing engine compression ratio,increasing hydrogenation energy ratio and adjusting ignition advance Angle on the economic performance,combustion performance and emission performance of natural gas engines are studied.In this study,a heavy-duty natural gas engine with high compression ratio,exhaust turbocharging,spark plug ignition and premixed combustion was modified,and then by high precision testing equipment,reasonable sensor layout and rigorous testing process to get the accurate and reliable test data.Then,analysis and summary on the test data,it is concluded that adjust the proportion of hydrogenation,ignition advance Angle and compression ratio of gas engine control parameters,such as the impact of,and use the relevant theoretical knowledge of the impact of root cause analysis.Finally,the effective methods to improve the thermal efficiency of natural gas engine and reduce the pollutant emission of natural gas engine are obtained by combining theoretical analysis and test data.In this paper,the thermal efficiency is improved by increasing the compression ratio,the combustion is accelerated by increasing the hydrogenation,and the thermal work conversion efficiency of the natural gas engine is further improved.In addition,EGR and delayed ignition advance Angle are introduced to reduce the increase of NOx caused by the increase of compression ratio and hydrogenation.Through the "collaborative research" of these control parameters,the effect of energy saving and emission reduction can be achieved at the same time.In this paper,the main conclusions are: natural gas engines in low and middle load at low speed(1000 r/min,BMEP is 4 bar),the appropriate increase the compression ratio and increase the hydrogen energy than can make equivalent than gas consumption is reduced 50%,the average effective thermal efficiency increases,the combustion location points ahead of 10% to 90%,the combustion duration shorten increased,the maximum explosion pressure and maximum pressure rise rate rise,NOx emission increases,HC emissions;In the condition of low speed high load(1000 r/min,BMEP is 8 bar),proper increase of ignition advance Angle can lead to equivalent than gas consumption reduced 50%,the average effective thermal efficiency increases,the combustion location points ahead of 10% to 90%,the combustion duration shorten increased,the maximum explosion pressure and maximum pressure rise rate increased NOx emissions increase,HC emission s increase.The introduction of EGR will greatly reduce NOx emissions without changing the in-cylinder combustion parameters.