The Research Of The Control System For COG/Gasoline Duel Fuel Engine

As the population and production of global cars increase every year, energy and environmental issues have became a global agenda for sustainable development, leading people to focus on alternative fuels of Internal Combustion Engine (ICE). Gas fuels, especially natural gas and hydrogen, have been widely attention for their low emissions and wide resources. As the same time, China is the largest country in the production of coke. However most of coke oven gas (COG), a by-product in coking, is wasted by burning or releasing into air directly, resulting in energy waste and environmental pollution. Hydrogen and methane are both the ideal alternative fuels for automobiles. So if key problems of COG utilization for ICE can be overcame, especially for ICE of automobiles, great economic and social benefits will follow.This research is a part of major science and technology projects of Guizhou Province, research of key technology and application of coke oven gas (COG) vehicle. With the analysis of functional requirements of MPI COG/gasoline dual fuel engine, this thesis proposes the overall design of a master-slave duel ECU system. And the transformation of gasoline engine bench is completed.Base on Freescale MC9S12XEP100microcontroller, the hardware system of COG ECU is proposed, mainly including minimum system circuit, signal adjust circuits, ignition and injection circuits, fuel switching circuits, communication interface circuits. The software system of COG ECU is proposed according to the hardware system, consisting of four parts:crank control strategy, fuel switching control strategy, injection control strategy and ignition control strategy.As the original ECU can’t fully play the advantage and performance of COG, the research of injection pulse width and spark advance of COG is carried out. With analysis of the flow characteristics of gasoline nozzle and COG nozzle, COG pulse width is calculated related to gasoline pulse width and the temperature and pressure of COG. The one-dimensional GT-power simulation model is built and verified compared with bench test. With the simulation model, the MBT spark advances of COG engine are forecasted.Based on the self-developed SMR HIL simulation platform, the function of COG ECU is tested and verified. Results show this system achieves the expected design.