Study On Co-combustion Of An LNG/Diesel Duel Fuel Vehicle Engine

With the rapid development of the automobile industry, our country’s vehiclepopulation is also increasing rapidly, which brings environmental pollution and theshortage of petroleum. So clean alternative fuel is explored and implied whichcontinuously promoted the development of automobile industry. Among the variety ofalternative fuels, Natural Gas, which embraces the characteristics of abundantresources, higher octane value, lower pollution and mature technology, is regarded asa very promising clean vehicle fuel. Therefore，it will be a new direction fordeveloping the natural gas engines，and it is also an effective method to solve the oilcrisis and the environmental problems. LNG/diesel dual fuel vehicle has beenreceived more and more attention for its advantages such as long mileage, convenientrefitting, good economy, and lower pollution.Based on domestic and overseas research results, this paper conduct in-depthdiscussions about exploitation and performance test of a dual-fuel engine. It discuss indetail about the natural gas supply system, dual-fuel electronic control system andthose equipment used in the test. Then, dual-fuel engine co-combustion characteristicstest is completed. The test is designed to study the effects of co-combustion ratio onLNG/diesel dual fuel engine’s power, fuel consumption, exhaust emissions, whichprovides the research foundation for LNG/diesel dual fuel engine’s optimal control.The Co-combustion characteristics have been studied at2200r/min. The main testitems include specific fuel consumption (SFC), power, torque and exhausttemperature, and the exhaust emissions include carbon dioxide (CO2), hydrocarbon(HC), nitrogen oxides (NOx), smoke and carbon monoxide (CO) emissions.The experimental results show that, the co-combustion ratio may reaches92.3%at2200r/min. It can fulfill the low fuel consumption and eco-friendly emissions, whenfuelled with diesel fuel only at low-load ratio, and switched to a high co-combustionratio of LNG-Diesel duel fuel at high-load ratio.