Study On Performance And Emission Of A Methanol-Diesel Dual-Fuel Engine

With the rapid development of the automotive industry, our country’s vehicle population is also increasing rapidly. Automobiles bring convenience while the environmental pollution which the automobile industry yielded and the shortage of oil are progressively turned into serious. So it is significant method which continuously promoted development of auto industry that clean alternative fuel is explored and implied. Among the variety of alternative fuels, methanol which embraces the characteristics such as high oxygen content, lower pollution and low production costs is regarded as a very promising cleaning vehicle fuel. Therefore,it will be a new direction for developing the methanol engines, and it is also an effective method to solve the oil crisis and the environmental problems. Methanol-diesel fuel dual fuel engine has been receiving more and more attention for its advantages such as good performance, convenient refitting and flexible use.Based on domestic and overseas research results, this paper conducted in-depth discussions about exploitation and performance test of the dual-fuel engine. It discusses in detail about the methanol supply system, dual-fuel electric control system and the equipments used in the test. Then, dual-fuel engine co-combustion characteristics test is completed. The test is designed to study the effects of co-combustion ratio on methanol-diesel dual-fuel engine’s power, specific fuel consumption, exhaust emissions, which provides the research foundation for methanol-diesel dual-fuel engine’s optimal control. The co-combustion characteristics have been analyzed at the speed of 1400 r/min under 15%, 25%, 40%, 60% and 100% of load ratios. The load characteristics also have been analyzed at the speed of 1000 r/min and 1400 r/min comparing dual-fuel engine with the diesel engine. The main test items include specific fuel consumption(SFC), power, torque and exhaust temperature, and the exhaust emissions include carbon dioxide(CO2), hydrocarbon(HC), nitrogen oxides(NOX), smoke and carbon monoxide(CO).The experimental results show that, the co-combustion ratio may reaches 55.28% at 1400r/min. When compared to the diesel operation, the dual fuel operation shows less specific fuel consumption with good fuel economy; the emissions of HC and CO are higher, but emissions of NOX and smoke are lower; the exhaust temperature is lower. It can fulfill the low fuel consumption and eco-friendly emissions, when fuelled with diesel fuel at low-load ratio, and switched to methanol-diesel dual-fuel at high-load ratios.