In this paper, we study the best-mixture ratio of biodiesel-ethanol-diesel for diesel engines. The simulation results show that the integrated indexes including engine power, cost-effectiveness and emission properties...In this paper, we study the best-mixture ratio of biodiesel-ethanol-diesel for diesel engines. The simulation results show that the integrated indexes including engine power, cost-effectiveness and emission properties are rather better with different optimizing index when the ratio of bio-diesel, ethanol and diesel are 71.58:2.72:25.70 and 50:2.4127:47.5873.展开更多
Evaporation plavs an important role in the cylinder combustion process.so the study of fiel evaporation characteristics is very important to improve the combustion performance of internal combustion engine.In this stu...Evaporation plavs an important role in the cylinder combustion process.so the study of fiel evaporation characteristics is very important to improve the combustion performance of internal combustion engine.In this study,ethanol diesel was used as the base fuel.The evaporation characteristics of droplets at different ambient temperatures(623 K.923 K)were investigated by adding alumina nanoparticles with different mass fractions(1%,2.5%)to ethanol diesel.The results show that the evaporation states of three kinds of droplets(et hanol diesel,base fuel with 1%alumina nanoparticles,base fuel with 2.5%alumina nanoparticles)are similar in the low temperature environment,and nanoparticles inhibit the evaporation of the droplets.At low temperature,the higher the concentration of nanoparticles is,the slower the evaporation rate is.However.in the high temperature environment,nanoparticles significantly promote droplet evaporation.and the phenomenon of micro explosion is obvious.By analvzine the evaporation processes of two different temperatures,we kuow that nanoparticles first.gather on the surface of the droplet,theu form a protective shell,and finally reduce the evaporation rate of the droplet at low temperature.In the high temperature environment,mucleation sites and bubbles are formed in the interior of the droplet:as the droplet is heated further,mucleation sites and bubbles first gather and then fuse:the bubbles gradually expand and burst rapidly.causing micro explosion of the droplets.and most of them are evaporated in the micro explosion.展开更多
The preparation of ethanol-diesel fuel blends and their emission characteristics were investigated. Results showed the absolute ethanol can dissolve in diesel fuel at an arbitrary ratio and a small quantity of water(0...The preparation of ethanol-diesel fuel blends and their emission characteristics were investigated. Results showed the absolute ethanol can dissolve in diesel fuel at an arbitrary ratio and a small quantity of water(0.2%) addition can lead to the phase separation of blends. An organic additive was synthesized and it can develop the ability of resistance to water and maintain the stability of ethanol-diesel-trace amounts of water system. The emission characteristics of 10%, 20%, and 30% ethanol-diesel fuel blends, with or without additives, were compared with those of diesel fuel in a direct injection(DI) diesel engine. The experimental results indicated that the blend of ethanol with diesel fuel significantly reduced the concentrations of smoke, hydrocarbon(HC), and carbon monoxide(CO) in exhaust gas. Using 20% ethanol-diesel fuel blend with the additive of 2% of the total volume, the optimum mixing ratio was achieved, at which the bench diesel engine testing showed a significant decrease in exhaust gas. Bosch smoke number was reduced by 55%, HC emission by 70%, and CO emission by 45%, at 13 kW/1540 r/min. However, ethanol-diesel fuel blends produced a few ppm acetaldehydes and more ethanol in exhaust gas.展开更多
The primary barrier to the use of ethanol in diesel fuel is the poor miscibility at lower temperatures. The miscibilities of ethanol in 19 diesel fuels having a wide variation in compositions were evaluated by testin...The primary barrier to the use of ethanol in diesel fuel is the poor miscibility at lower temperatures. The miscibilities of ethanol in 19 diesel fuels having a wide variation in compositions were evaluated by testing their phase separation temperatures. The result shows that aromatic contents and intermediate distillate temperatures have a significant impact on miscibility limits. The FCC diesels, which contain up to 50% of aromatics, exhibit different phase behavior trends in comparison with straight-run diesels and other diesel fuels.展开更多
Over the last decade, the uptake rate of first-generation biofuels (ethanol and biodiesel) has decelerated as low blend limits have increased only slowly and extreme volatility in oil prices has limited investment in ...Over the last decade, the uptake rate of first-generation biofuels (ethanol and biodiesel) has decelerated as low blend limits have increased only slowly and extreme volatility in oil prices has limited investment in biofuels production infrastructure. Concerns over the environmental impacts of large-scale biofuels production combined with tariff barriers have greatly restricted the global trade in biofuels. First-generation biofuels produced either by fermentation of sugars from maize or sugarcane (ethanol) or transesterification of triglycerides (biodiesel) presently contribute less than 4% of terrestrial transportation fuel demand and techno-economic modelling foresees this only slowly increasing by 2035. With internal combustion and diesel engines widely anticipated as being phased out in favour of electric power for motor vehicles, a much-reduced market demand for biofuels is likely if global demand for all liquid fuels declines by 2050. However, second-generation, thermochemically produced and biomass-derived fuels (renewable diesel, marine oils and sustainable aviation fuel) have much higher blend limits;combined with policies to decarbonise the aviation and marine industries, major new markets for these products in terrestrial, marine and aviation sectors may emerge in the second half of the 21st century.展开更多
文摘In this paper, we study the best-mixture ratio of biodiesel-ethanol-diesel for diesel engines. The simulation results show that the integrated indexes including engine power, cost-effectiveness and emission properties are rather better with different optimizing index when the ratio of bio-diesel, ethanol and diesel are 71.58:2.72:25.70 and 50:2.4127:47.5873.
基金the Foundation Research Project of Jiangsu Province(the Natural Science Fund:No.BK20180982)。
文摘Evaporation plavs an important role in the cylinder combustion process.so the study of fiel evaporation characteristics is very important to improve the combustion performance of internal combustion engine.In this study,ethanol diesel was used as the base fuel.The evaporation characteristics of droplets at different ambient temperatures(623 K.923 K)were investigated by adding alumina nanoparticles with different mass fractions(1%,2.5%)to ethanol diesel.The results show that the evaporation states of three kinds of droplets(et hanol diesel,base fuel with 1%alumina nanoparticles,base fuel with 2.5%alumina nanoparticles)are similar in the low temperature environment,and nanoparticles inhibit the evaporation of the droplets.At low temperature,the higher the concentration of nanoparticles is,the slower the evaporation rate is.However.in the high temperature environment,nanoparticles significantly promote droplet evaporation.and the phenomenon of micro explosion is obvious.By analvzine the evaporation processes of two different temperatures,we kuow that nanoparticles first.gather on the surface of the droplet,theu form a protective shell,and finally reduce the evaporation rate of the droplet at low temperature.In the high temperature environment,mucleation sites and bubbles are formed in the interior of the droplet:as the droplet is heated further,mucleation sites and bubbles first gather and then fuse:the bubbles gradually expand and burst rapidly.causing micro explosion of the droplets.and most of them are evaporated in the micro explosion.
文摘The preparation of ethanol-diesel fuel blends and their emission characteristics were investigated. Results showed the absolute ethanol can dissolve in diesel fuel at an arbitrary ratio and a small quantity of water(0.2%) addition can lead to the phase separation of blends. An organic additive was synthesized and it can develop the ability of resistance to water and maintain the stability of ethanol-diesel-trace amounts of water system. The emission characteristics of 10%, 20%, and 30% ethanol-diesel fuel blends, with or without additives, were compared with those of diesel fuel in a direct injection(DI) diesel engine. The experimental results indicated that the blend of ethanol with diesel fuel significantly reduced the concentrations of smoke, hydrocarbon(HC), and carbon monoxide(CO) in exhaust gas. Using 20% ethanol-diesel fuel blend with the additive of 2% of the total volume, the optimum mixing ratio was achieved, at which the bench diesel engine testing showed a significant decrease in exhaust gas. Bosch smoke number was reduced by 55%, HC emission by 70%, and CO emission by 45%, at 13 kW/1540 r/min. However, ethanol-diesel fuel blends produced a few ppm acetaldehydes and more ethanol in exhaust gas.
文摘The primary barrier to the use of ethanol in diesel fuel is the poor miscibility at lower temperatures. The miscibilities of ethanol in 19 diesel fuels having a wide variation in compositions were evaluated by testing their phase separation temperatures. The result shows that aromatic contents and intermediate distillate temperatures have a significant impact on miscibility limits. The FCC diesels, which contain up to 50% of aromatics, exhibit different phase behavior trends in comparison with straight-run diesels and other diesel fuels.
文摘Over the last decade, the uptake rate of first-generation biofuels (ethanol and biodiesel) has decelerated as low blend limits have increased only slowly and extreme volatility in oil prices has limited investment in biofuels production infrastructure. Concerns over the environmental impacts of large-scale biofuels production combined with tariff barriers have greatly restricted the global trade in biofuels. First-generation biofuels produced either by fermentation of sugars from maize or sugarcane (ethanol) or transesterification of triglycerides (biodiesel) presently contribute less than 4% of terrestrial transportation fuel demand and techno-economic modelling foresees this only slowly increasing by 2035. With internal combustion and diesel engines widely anticipated as being phased out in favour of electric power for motor vehicles, a much-reduced market demand for biofuels is likely if global demand for all liquid fuels declines by 2050. However, second-generation, thermochemically produced and biomass-derived fuels (renewable diesel, marine oils and sustainable aviation fuel) have much higher blend limits;combined with policies to decarbonise the aviation and marine industries, major new markets for these products in terrestrial, marine and aviation sectors may emerge in the second half of the 21st century.
