The combustion characteristics and emission behaviors of RP-3 jet fuel were studied and compared to commercial diesel fuel in a single-cylinder compression ignition(CI)engine.Engine operational parameters,including en...The combustion characteristics and emission behaviors of RP-3 jet fuel were studied and compared to commercial diesel fuel in a single-cylinder compression ignition(CI)engine.Engine operational parameters,including engine load(0.6,0.7,and 0.8 MPa indicating the mean effective pressure(IMEP)),the exhaust gas recirculation(EGR)rate(0%,10%,20%,and 30%),and the fuel injection timing(–20,–15,–10,and–5°crank angle(CA)after top dead center(ATDC))were adjusted to evaluate the engine performances of RP-3 jet fuel under changed operation conditions.In comparison to diesel fuel,RP-3 jet fuel shows a retarded heat release and lagged combustion phase,which is more obvious under heavy EGR rate conditions.In addition,the higher premixed combustion fraction of RP-3 jet fuel leads to a higher first-stage heat release peak than diesel fuel under all testing conditions.As a result,RP-3 jet fuel features a longer ignition delay(ID)time,a shorter combustion duration(CD),and an earlier CA50 than diesel fuel.The experimental results manifest that RP-3 jet fuel has a slightly lower indicated thermal efficiency(ITE)compared to diesel fuel,but the ITE difference becomes less noticeable under large EGR rate conditions.Compared with diesel fuel,the nitrogen oxides(NOx)emissions of RP-3 jet fuel are higher while its soot emissions are lower.The NOx emissions of RP-3 can be effectively reduced with the increased EGR rate and delayed injection timing.展开更多
Honne oil(tamanu)(H),a non-edible vegetable oil is native for northwards of Northern Marianas islands and the Ryukyu Islands in southern Japan and westward throughout Polynesia.It has remained as an untapped new possi...Honne oil(tamanu)(H),a non-edible vegetable oil is native for northwards of Northern Marianas islands and the Ryukyu Islands in southern Japan and westward throughout Polynesia.It has remained as an untapped new possible source of alternative fuel that can be used as diesel engine fuel.Literature pertaining to use of vegetable oil in diesel engine with kerosene and dimethyl carbonate(DMC)is scarce.The present research is aimed to investigate experimentally the performance,exhaust emission and combustion characteristics of a direct injection(DI)diesel engine,typically used in agricultural sector,over the entire load range,when fuelled with neat diesel(ND)and blends of diesel fuel(D)/DMC/H/kerosene(K).DMC/D/H/K blends have a potential to improve the performance and emissions and to be an alternative to ND.Experiments have been conducted when fuelled with H20(20%H+80%D),HK(20%H+40%K+40%D)and HKD5(20%H+40%K+35D+5%DMC)to HKD15 in steps of 5%DMC keeping H and K percentages constant.The emissions(CO,HC and smoke density(SD))of fuel blend HKD15 are found to be lowest,with SD dropping significantly.The NOx level is slightly higher with HKD5 to HKD15 as compared to ND.The brake thermal efficiency of HKD5 to HKD15 is same and it is higher than that of ND.There is a good trade off between NOx and SD.Peak cylinder pressure and premixed combustion phase increases as DMC content increase.展开更多
In order to reduce the pollutant emission and alleviate the pressure of petroleum resources shortage and greenhouse gas emission at the same time,the use of clean and renewable alternative fuel for marine engines is a...In order to reduce the pollutant emission and alleviate the pressure of petroleum resources shortage and greenhouse gas emission at the same time,the use of clean and renewable alternative fuel for marine engines is a promising option.In this study,a marine diesel engine,which was modified to run in diesel methanol compound combustion (DMCC) mode,was investigated.After the diesel injection parameters were calibrated,and combined with a sample after-treatment device DOC (diesel oxidation catalyst),the engine could meet the requirements of China II legislation.The overall MSP (methanol substitute percent) reached 54.1%.The value of each pollutant emission was much lower than that in China II emission legislation,and there was almost no methanol and formaldehyde emissions.When methanol was injected into the inlet manifold,the intake air temperature decreased a lot,as well as the exhaust gas temperature,which were beneficial to increase engine thermal efficiency and improve engine room environment.Compared with the engine running in pure diesel mode,when the engine ran in diesel/methanol dual fuel mode,the combustion phase was advanced,and the combustion duration became shorter.Therefore,the engine thermal efficiency increased,and fuel consumption decreased significantly.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52022058,51776124,51861135303)the Ministry of Education of China(Grant No.6141A020335).
文摘The combustion characteristics and emission behaviors of RP-3 jet fuel were studied and compared to commercial diesel fuel in a single-cylinder compression ignition(CI)engine.Engine operational parameters,including engine load(0.6,0.7,and 0.8 MPa indicating the mean effective pressure(IMEP)),the exhaust gas recirculation(EGR)rate(0%,10%,20%,and 30%),and the fuel injection timing(–20,–15,–10,and–5°crank angle(CA)after top dead center(ATDC))were adjusted to evaluate the engine performances of RP-3 jet fuel under changed operation conditions.In comparison to diesel fuel,RP-3 jet fuel shows a retarded heat release and lagged combustion phase,which is more obvious under heavy EGR rate conditions.In addition,the higher premixed combustion fraction of RP-3 jet fuel leads to a higher first-stage heat release peak than diesel fuel under all testing conditions.As a result,RP-3 jet fuel features a longer ignition delay(ID)time,a shorter combustion duration(CD),and an earlier CA50 than diesel fuel.The experimental results manifest that RP-3 jet fuel has a slightly lower indicated thermal efficiency(ITE)compared to diesel fuel,but the ITE difference becomes less noticeable under large EGR rate conditions.Compared with diesel fuel,the nitrogen oxides(NOx)emissions of RP-3 jet fuel are higher while its soot emissions are lower.The NOx emissions of RP-3 can be effectively reduced with the increased EGR rate and delayed injection timing.
文摘Honne oil(tamanu)(H),a non-edible vegetable oil is native for northwards of Northern Marianas islands and the Ryukyu Islands in southern Japan and westward throughout Polynesia.It has remained as an untapped new possible source of alternative fuel that can be used as diesel engine fuel.Literature pertaining to use of vegetable oil in diesel engine with kerosene and dimethyl carbonate(DMC)is scarce.The present research is aimed to investigate experimentally the performance,exhaust emission and combustion characteristics of a direct injection(DI)diesel engine,typically used in agricultural sector,over the entire load range,when fuelled with neat diesel(ND)and blends of diesel fuel(D)/DMC/H/kerosene(K).DMC/D/H/K blends have a potential to improve the performance and emissions and to be an alternative to ND.Experiments have been conducted when fuelled with H20(20%H+80%D),HK(20%H+40%K+40%D)and HKD5(20%H+40%K+35D+5%DMC)to HKD15 in steps of 5%DMC keeping H and K percentages constant.The emissions(CO,HC and smoke density(SD))of fuel blend HKD15 are found to be lowest,with SD dropping significantly.The NOx level is slightly higher with HKD5 to HKD15 as compared to ND.The brake thermal efficiency of HKD5 to HKD15 is same and it is higher than that of ND.There is a good trade off between NOx and SD.Peak cylinder pressure and premixed combustion phase increases as DMC content increase.
基金financial support provided by the Natural Science Foundation of China (No.51676134)。
文摘In order to reduce the pollutant emission and alleviate the pressure of petroleum resources shortage and greenhouse gas emission at the same time,the use of clean and renewable alternative fuel for marine engines is a promising option.In this study,a marine diesel engine,which was modified to run in diesel methanol compound combustion (DMCC) mode,was investigated.After the diesel injection parameters were calibrated,and combined with a sample after-treatment device DOC (diesel oxidation catalyst),the engine could meet the requirements of China II legislation.The overall MSP (methanol substitute percent) reached 54.1%.The value of each pollutant emission was much lower than that in China II emission legislation,and there was almost no methanol and formaldehyde emissions.When methanol was injected into the inlet manifold,the intake air temperature decreased a lot,as well as the exhaust gas temperature,which were beneficial to increase engine thermal efficiency and improve engine room environment.Compared with the engine running in pure diesel mode,when the engine ran in diesel/methanol dual fuel mode,the combustion phase was advanced,and the combustion duration became shorter.Therefore,the engine thermal efficiency increased,and fuel consumption decreased significantly.
文摘为了改善柴油机燃烧室内燃油喷雾撞壁和混合气形成情况,提出一种直喷式柴油机多点分布式导向台燃烧室。将这种新燃烧室结构参数化,对7个设计变量进行多参数协同优化。以一台230 mm缸径的中速船用柴油机为基础模拟缸内工作过程,采用拉丁超立方取样的方法从设计空间得到600个样本点,根据模拟结果分析各设计参数对发动机性能的影响,根据不同的优化目标得到3种新燃烧室结构。仿真结果表明:在75%负荷工况下与原机ω型燃烧室相比,Ⅰ型燃烧室的指示油耗率(indicated specific fuel consumption,ISFC)降低1.83%,烟粒(soot)排放量降低86.83%;Ⅱ型燃烧室的ISFC降低0.97%,NO_(x)排放量降低7.44%,soot排放量降低68.26%;Ⅲ型燃烧室的INO_(x)和soot排放量分别降低10.52%和58.08%,ISFC基本不变。
