Research On Hydrous-ethanol Reforming Fuel Engine

At present the nonrenewable fossil fuel is the main energy source human-being depend on.But the researches for the reserve/production ratio of fossil fuel indicate the durative time of fossil fuel production is limited.The serious emission of greenhouse gas and warming of the climate are induced by large scale application of fossil fuel which introduces the carbon depositing under the ground hundreds of millions years to the aerosphere.With the development of the economy, human-being are forced to search new alternative energy by energy consume increasing,energy source reserve decreasing and the environment worsening.Solar,wind,ocean,geothermal and biomass are the potential alternative energy sources in the future.To the technology of present status,biodiesel and bioethanol are fit for the transport facilities in comparison with all other alternative fuels because of its relatively greater power density.The technology of ethanol as engine alternative fuel is ripest for ethanol-gasoline widely application in the market.But the ratio of ethanol in ethanol-gasoline used to the existing engines couldn't be over 10%,and there are many structure modifications to the existing engines using high ratio ethanol-gasoline.And ethanol-gasoline needs dehydrated ethanol which purity must be over 99.5%.The hydrous-ethanol reforming approach presented in this paper could overcome above shortcomings,which applies hydrous-ethanol to the existing engines directly.The principle of the approach is that hydrous-ethanol is reformed to hydrogen-rich gas mixture for engine combustion,and the energy source for ethanol steam evaporating and reforming comes from the waste heat of engine exhaust.To support the development of hydrous-ethanol reforming fuel engines(RE), the main aim of this paper is to research the characters of hydrous-ethanol reforming fuel,study the intrinsic factors of the fuel which improve engine thermal efficiency, and put forward the optimizing strategies for engine performances.The main contents include:1) The research background,aim and significance have been discussed.2) The reforming rules of ethanol steam with catalyst under the conditions provided by running engine have been studied.Hydrogen-rich gas mixture could be produced by ethanol steam reforming with catalyst;under the comparable conditions,the reforming ratio would be improved with temperature increasing and with alcohol concentrate increasing,and decreased with alcohol flux increasing.3) The characters of hydrous-ethanol reforming fuel have been analyzed.Heat value of hydrous-ethanol reforming fuel is increased,and combustion performance is improved due to hydrogen-rich.But the gas form of it brings negative influence to engine charge coefficient,and moles shrinkage in combustion partly offsets the positive effect from increased heat value and improved combustion performance.4) Engine theory cycle with hydrous-ethanol reforming fuel/air mixture is studied.With reforming ratio increasing,the maximal temperature and thermal efficiency of theory cycle is increasing,but the maximal pressure would be decreasing with reforming ratio increasing due to influence of moles.5) Kit experiment results of RE compared to that of hydrous-ethanol vapor engine(VE) are studied.The thermal efficiency of RE is higher than that of VE because hydrogen-rich RE fuel realizes quick combustion and lean combustion.6) Optimizing strategies for performances of RE based on existing engine have been researched.The economy and emission performances of RE could be improved by increasing compression ratio and ignition angle,and realizing lean combustion.Compared to the baseline gasoline engine,optimized RE performances including energy consuming and emissions are improved greatly except of power performance.