Internal combustion engines′ fuel economy is an important role for engine designers,engine manufacturers over the past 30 years,especially passenger car motor oils.In heavy duty diesel engine,over the past 20 years,f...Internal combustion engines′ fuel economy is an important role for engine designers,engine manufacturers over the past 30 years,especially passenger car motor oils.In heavy duty diesel engine,over the past 20 years,fuel economy has in some cases been sacrificed for exhaust gas emission optimizations.Now,Heavy Duty Automotive and the related industries have strong interest in fuel economy and the lubricants.It is driven by competitive market forces as well as government mandates and new emission regulations.Japan was the first country in the world to establish and implement heavy duty trucks and buses fuel economy standards.Other countries also have followed either by establishing direct fuel economy standards or greenhouse gas(GHG) emissions standards which are directly tied to fuel economy.This paper is discussing that heavy duty diesel engine lubricants can contribute on fuel economy.The contribution of various aspects of engine oil formulations on fuel economy will be discussed such as lubricant viscosity grade,lubricant additives and friction modifiers.In this paper,the evaluation discussions are based on fuel economy measurements in some bench tests,standardized laboratory engine tests and field tests.展开更多
Co-contamination of diesel fuel and heavy metals can be challenging for microbial remediation due to the complex composition of the fuel and the inhibitory effect of heavy metals.There is an urgent need to study this ...Co-contamination of diesel fuel and heavy metals can be challenging for microbial remediation due to the complex composition of the fuel and the inhibitory effect of heavy metals.There is an urgent need to study this interaction to improve the pollutant removal efficiency in the Polar Regions.The growth of an Antarctic bacterium,Rhodococcus sp.was studied by comparing the growth at the logarithmic phase under the effect of selected heavy metals(Pb,Cr,As,Cd,Cu,Zn,Ni,Hg and Co).The selected heavy metals inhibited the growth of the Rhodococcus sp.on diesel fuel in an order from highest to lowest of:Hg>Zn>Cd>Cu>Co>Ni>As>Pb>Cr.Growth on diesel fuel co-contaminated with Hg and Zn were 2.95%and 5.71%,respectively compared to the no-metal control.A further experiment with various Zn concentrations was conducted.The specific growth rate of Rhodococcus sp.co-contaminated with different concentrations of Zn showed a correlation coefficient(r)of 0.916,and was modelled with an exponential decay model.Additional investigation is needed to determine the effect of low concentration of Zn on hydrocarbon degradation.It is important to understand the relationships between microbes,hydrocarbons and heavy metals,especially in the Polar Regions because this interaction might be promising in treating hydrocarbon-polluted sites containing heavy metals.The data and results also provide baseline tools of bioremediation processes at low temperatures and the knowledge of the ecological roles of Rhodococcus sp.in Antarctica.展开更多
In this work,particulate matter(PM) emissions from a large two-stroke,low-speed marine diesel engine were investigated when the engine was operated with low-sulfur heavy fuel oil(HFO) at various loads.Particle samples...In this work,particulate matter(PM) emissions from a large two-stroke,low-speed marine diesel engine were investigated when the engine was operated with low-sulfur heavy fuel oil(HFO) at various loads.Particle samples were collected in situ from the engine exhaust to determine the detailed physical and chemical properties.The nanostructure and morphology of the nanoparticles were analyzed using transmission electron microscopy images(TEM).The results show that volatile organic carbon(OC) accounts for more than 80% in the HFO particles and leads to an increase in particle size.The thermodynamic conditions of a low-speed engine favor the behavior of capturing the soluble organic components.A large number of spherical char HFO particles with aerodynamic diameters of 0.2 μm-0.5 μm and a suspected inner metal core were detected.The two peak aerodynamic diameters of the HFO nanoparticles are 15 nm and 86 nm.The morphological differences among the HFO nanoparticles in varied engine conditions represent the formation process from primary nascent particles to mature graphitized particles caused by thermodynamics.The above study will be valuable for understanding the characteristics of PM emissions from low-sulfur HFO to achieve the ship PM emissions reduction target.展开更多
文摘Internal combustion engines′ fuel economy is an important role for engine designers,engine manufacturers over the past 30 years,especially passenger car motor oils.In heavy duty diesel engine,over the past 20 years,fuel economy has in some cases been sacrificed for exhaust gas emission optimizations.Now,Heavy Duty Automotive and the related industries have strong interest in fuel economy and the lubricants.It is driven by competitive market forces as well as government mandates and new emission regulations.Japan was the first country in the world to establish and implement heavy duty trucks and buses fuel economy standards.Other countries also have followed either by establishing direct fuel economy standards or greenhouse gas(GHG) emissions standards which are directly tied to fuel economy.This paper is discussing that heavy duty diesel engine lubricants can contribute on fuel economy.The contribution of various aspects of engine oil formulations on fuel economy will be discussed such as lubricant viscosity grade,lubricant additives and friction modifiers.In this paper,the evaluation discussions are based on fuel economy measurements in some bench tests,standardized laboratory engine tests and field tests.
基金supported by Universiti Putra Malaysia attached to WLWJ(Grant no.GP-IPM/2013/9422700)。
文摘Co-contamination of diesel fuel and heavy metals can be challenging for microbial remediation due to the complex composition of the fuel and the inhibitory effect of heavy metals.There is an urgent need to study this interaction to improve the pollutant removal efficiency in the Polar Regions.The growth of an Antarctic bacterium,Rhodococcus sp.was studied by comparing the growth at the logarithmic phase under the effect of selected heavy metals(Pb,Cr,As,Cd,Cu,Zn,Ni,Hg and Co).The selected heavy metals inhibited the growth of the Rhodococcus sp.on diesel fuel in an order from highest to lowest of:Hg>Zn>Cd>Cu>Co>Ni>As>Pb>Cr.Growth on diesel fuel co-contaminated with Hg and Zn were 2.95%and 5.71%,respectively compared to the no-metal control.A further experiment with various Zn concentrations was conducted.The specific growth rate of Rhodococcus sp.co-contaminated with different concentrations of Zn showed a correlation coefficient(r)of 0.916,and was modelled with an exponential decay model.Additional investigation is needed to determine the effect of low concentration of Zn on hydrocarbon degradation.It is important to understand the relationships between microbes,hydrocarbons and heavy metals,especially in the Polar Regions because this interaction might be promising in treating hydrocarbon-polluted sites containing heavy metals.The data and results also provide baseline tools of bioremediation processes at low temperatures and the knowledge of the ecological roles of Rhodococcus sp.in Antarctica.
基金supported by the Science & Technology Commission of Shanghai MunicipalityShanghai Engineering Research Center of Ship Intelligent Maintenance and Energy Efficiency under Grant 20DZ2252300。
文摘In this work,particulate matter(PM) emissions from a large two-stroke,low-speed marine diesel engine were investigated when the engine was operated with low-sulfur heavy fuel oil(HFO) at various loads.Particle samples were collected in situ from the engine exhaust to determine the detailed physical and chemical properties.The nanostructure and morphology of the nanoparticles were analyzed using transmission electron microscopy images(TEM).The results show that volatile organic carbon(OC) accounts for more than 80% in the HFO particles and leads to an increase in particle size.The thermodynamic conditions of a low-speed engine favor the behavior of capturing the soluble organic components.A large number of spherical char HFO particles with aerodynamic diameters of 0.2 μm-0.5 μm and a suspected inner metal core were detected.The two peak aerodynamic diameters of the HFO nanoparticles are 15 nm and 86 nm.The morphological differences among the HFO nanoparticles in varied engine conditions represent the formation process from primary nascent particles to mature graphitized particles caused by thermodynamics.The above study will be valuable for understanding the characteristics of PM emissions from low-sulfur HFO to achieve the ship PM emissions reduction target.
