This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank ...This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank angle degree(CAD)before top dead center(BTDC)and a set of constant ignition timing tests while also keeping the 10℃AD BTDC injection and adding ignition improver(2-ethylhexylnitrate-,2-EHN)to the fuel mixtures.Soot particles were characterized using DMS-500 instrument in terms of mass,size,and number.The experimental results showed that adding 2-EHN to the model fuel blends reduced the soot surface area,soot mass concentration and soot mean size.Replacing 20 vol%of a C 7-heptane with 20 vol%methyl-decanoate(an oxygenated C 11 molecule)did not affect the ignition delay or rate of fuel air premixing,the peak in-cylinder pressure or heat release rates.Toluene addition(0−22.5 vol%)to heptane increased the mean size of the soot particles generated by only 3%while also resulted in a slight increase in the peak cylinder pressure and peak heat release rates.Blending toluene and methyl-decanoate into heptane without adding 2-EHN increased the premix phase fraction by at least 13%.However,by adding 2-EHN(4×10^(−4)−1.5×10^(−3)),the premixed phase fraction decreased by at least 11%.展开更多
In order to solve the failure of fuel system when using petroleum coke oil slurry (PCOS) in a R180 diesel engine directly,a petroleum coke oil slurry fuel system (PCOSFS) was developed and installed in R180 engine,whi...In order to solve the failure of fuel system when using petroleum coke oil slurry (PCOS) in a R180 diesel engine directly,a petroleum coke oil slurry fuel system (PCOSFS) was developed and installed in R180 engine,which was called PCOS engine.In order to analyze performances and emissions of the PCOS engine,a comparative experiment between PCOS engine fueled with PCOS and R180 engine fueled with diesel oil was carried out.The results show that the PCOS engine can run smoothly,the maximum output power decreases by about 6.2% and 19.0% and the maximum brake thermal efficiency reduces by around 5.85% and 4.13% as compared to R180 engine under the conditions of 1 200 and 1 600 r/min.The HC emissions of PCOS engine are lower than those of R180 engine at 1 200 r/min,and are close to those of R180 engine at 1 600 r/min.The CO emissions are similar to R180 engine at 1 200 and 1 600 r/min.The smoke intensity is close to R180 engine at 1 200 r/min,and is higher than R180 engine at 1 600 r/min.The particles emitted from PCOS engine array sparsely,but particles emitted from R180 engine array closely,cohering together.展开更多
文摘This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank angle degree(CAD)before top dead center(BTDC)and a set of constant ignition timing tests while also keeping the 10℃AD BTDC injection and adding ignition improver(2-ethylhexylnitrate-,2-EHN)to the fuel mixtures.Soot particles were characterized using DMS-500 instrument in terms of mass,size,and number.The experimental results showed that adding 2-EHN to the model fuel blends reduced the soot surface area,soot mass concentration and soot mean size.Replacing 20 vol%of a C 7-heptane with 20 vol%methyl-decanoate(an oxygenated C 11 molecule)did not affect the ignition delay or rate of fuel air premixing,the peak in-cylinder pressure or heat release rates.Toluene addition(0−22.5 vol%)to heptane increased the mean size of the soot particles generated by only 3%while also resulted in a slight increase in the peak cylinder pressure and peak heat release rates.Blending toluene and methyl-decanoate into heptane without adding 2-EHN increased the premix phase fraction by at least 13%.However,by adding 2-EHN(4×10^(−4)−1.5×10^(−3)),the premixed phase fraction decreased by at least 11%.
基金Project(2007BAA09B05)supported by the National Key Technology Research and Development Program of ChinaProject(50804004)supported by the National Natural Science Foundation of China
文摘In order to solve the failure of fuel system when using petroleum coke oil slurry (PCOS) in a R180 diesel engine directly,a petroleum coke oil slurry fuel system (PCOSFS) was developed and installed in R180 engine,which was called PCOS engine.In order to analyze performances and emissions of the PCOS engine,a comparative experiment between PCOS engine fueled with PCOS and R180 engine fueled with diesel oil was carried out.The results show that the PCOS engine can run smoothly,the maximum output power decreases by about 6.2% and 19.0% and the maximum brake thermal efficiency reduces by around 5.85% and 4.13% as compared to R180 engine under the conditions of 1 200 and 1 600 r/min.The HC emissions of PCOS engine are lower than those of R180 engine at 1 200 r/min,and are close to those of R180 engine at 1 600 r/min.The CO emissions are similar to R180 engine at 1 200 and 1 600 r/min.The smoke intensity is close to R180 engine at 1 200 r/min,and is higher than R180 engine at 1 600 r/min.The particles emitted from PCOS engine array sparsely,but particles emitted from R180 engine array closely,cohering together.
