Research On Combustion Emission Characteristics And Post-processing Technology Of Explosion-Proof Diesel Engine Fueled With F-T Diesel

Explosion-proof diesel engines are widely used in mine power machinery because of their high efficiency and safety.However,due to the installation of explosion-proof components,their combustion and emission performance deteriorate,which seriously influence the health of workers under the mine.This paper aims to improve the combustion and emission performance of explosion-proof diesel engines through a combination of in-machine purification and off-board purification.Coal-based F-T diesel is considered to be a clean and efficient alternative fuel for diesel engines because of its high cetane number,high combustion efficiency,low emissions and can be mixed with ordinary diesel oil in any proportion.The diesel oxidation catalyst(DOC)and the catalytic diesel particulate filter(CDPF)have become effective measures to reduce diesel exhaust emissions with their high conversion efficiency and capture efficiency.Therefore,the study of the effects of burning FT diesel and the addition of catalytic continuous regenerative particle trap(DOC+CDPF)on the performance of explosion-proof diesel engines and their working characteristics have theoretical guiding significance and practical application for improving the combustion and emission characteristics of explosion-proof diesel engines.In this paper,a certain type of explosion-proof diesel engine is used as a test prototype.The influence of burning F-T diesel and retrofitting equipment(DOC+CDPF)on the performance of explosion-proof diesel engine is tested and analyzed by bench test.Based on the actual engine bench test,the in-cylinder combustion model of explosion-proof diesel engine was built by CONVERGE software.The combustion characteristics of FT diesel were simulated and the DOC+CDPF one-dimensional coupling model was constructed by AVL BOOST software.The concentration change,temperature rise and pressure drop were simulated and analyzed.1)Using the engine bench test as the platform,0#diesel and F-T diesel are respectively burned on the explosion-proof diesel engine with the inlet and exhaust flame arrester and the washing tank.The results show that compared with the national VI 0#diesel,when using F-T diesel,the economics of the explosion-proof diesel engine is improved,the harmful emissions are greatly reduced,and the power is slightly reduced,but the requirements for use are fully met.In the case of external characteristics,when burning FT diesel,the fuel consumption rate decreased by 10.9%on average,CO,NO_x and PM emissions decreased by 80.2%,11.5%and 30.6%,respectively;under the eleven conditions,CO,NO_x and PM Emissions decreased by an average of 85.7%,33.9%and 43.4%,respectively,and F-T diesel can be used as a good clean alternative to explosion-proof diesel engines.2)Using CONVERGE software to simulate the in-cylinder combustion process of explosion-proof diesel engine fueled with F-T diesel and different fuel injection parameters.The results show that compared with 0#diesel,the pressure,temperature and heat release rate of the cylinder are reduced when burning F-T diesel,the combustion process is soft;with the delay of injection timing,the duration of injection and the spray The oil pressure is reduced,the NOx emissions are improved.3)The effects of DOC+CDPF on the performance of explosion-proof diesel engines using F-T diesel were analyzed by experiments.The conversion efficiency of DOC+CDPF when burning 0#diesel and F-T diesel were compared.The results show that the post-processing equipment DOC+CDPF can reduce the CO,NO_x and PM emissions of the explosion-proof diesel engine burning FT diesel,and the reduction effect on CO and PM emissions is very obvious.The post-treatment conversion for PM emissions using 0#diesel The efficiency efficiency is higher than that when burning FT diesel,but not for the conversion efficiency of gaseous emissions.4)Using AVL BOOST software to carry out one-dimensional simulation study on DOC+CDPF coupling equipment,the results show that the temperature rise phenomenon in DOC is not very obvious.The oxidation reaction is basically completed at 50%from the inlet,and the FT diesel fuel is used.In this case,the explosion-proof diesel engine can shorten the length of its DOC to save space;the pressure loss of CDPF is mainly due to its wall loss,and its initial soot amount,asymmetric result and inlet flow rate will affect its pressure drop.