This paper embraces the key points of unpolluted internally combusted engine emissions.Core objective is focused on the recent effort to improve compression ignition(CI)and spark ignition(SI)engine to have fuel⁃effici...This paper embraces the key points of unpolluted internally combusted engine emissions.Core objective is focused on the recent effort to improve compression ignition(CI)and spark ignition(SI)engine to have fuel⁃efficient and minimized pollutant emissions.There are many advanced internal combustion engines to overcome the challenges of conventional compression ignition engines of the high level of particulate matter(PM)and oxides of nitrogen emission.One of the latest options on which many researchers work recently is low⁃temperature combustion which studies the engine advancement and emission at the same time.This review focuses on the released emissions,incinerations and performances features of partially premixed charge ignition with different fuel blends like n⁃butanol⁃gasoline,gasoline⁃diesel,alcohol⁃diesel,and NG⁃diesel effect on partially premixed charge ignition(PPCI)engine combustion.Therefore,PPCI is a single or a dual fuel strategy in that a pre⁃mixed low or high reactive fuel(L/HRF)is directly injected into the engine.It is one of the best low⁃temperature combustion(LTC)strategies by which emissions are minimized while thermal efficiency is acceptable.The recent PPCI of various fuels and their effect are compared.Accordingly,the initial pilot injection can extend the operating load that is a problem in diesel engine;gasoline fuel displayed fewer soot releases when compared with diesel oil in all working situations.The additional inspiring outcome for this combustion approach can be directly controlled by using the start of injection timing(SOI),which is impossible with most other LTC concepts.The diesel PPCI can overcome the NOx⁃PM tradeoff but needs more EGR rates.Another problem of diesel engine PPCI is associated with its comparatively higher boiling point and relatively lower volatility,which made use of advanced injection with a great number of fuel challenges.Thus,diesel fuel is not the best candidate with the LRF to the PPCI engine setup.展开更多
The developing world still largely depends on biomass, such as wood, animal dung and agricultural waste for domestic fuel sources that are typically burned in traditional stoves. Ethiopia has different biomass resourc...The developing world still largely depends on biomass, such as wood, animal dung and agricultural waste for domestic fuel sources that are typically burned in traditional stoves. Ethiopia has different biomass resource for biochar production, through pyrolysis cook stove co-producing biochar. Coffee husks are the major solid residues from the handling and processing of coffee in the study area. This study was to evaluate the biochar co-producing pyrolysis cook stove with respect to heat transfer through the bed and biochar yield. From allothermal type of pyrolysis cook stove, the stove design was selected for both the computational fluid dynamic （CFD） simulation and experimental measurements. ANSYS 14.5 was used for CFD simulation of the wood combustion. The production of biochar from coffee husk, corncob and sawdust at different heating times, bed and stove surface temperature were undertaken. Bulk density, pH and surface area of the biochar were measured. While good agreement between simulation and experimental result was obtained in the conduction phase during pyrolysis, deviation between the two on account of the effect of volatile gas in changing the temperature trend within the biomass bed was noticed. Within the biomass type, the maximum mean biochar yield （38.91%） was seen from coffee husk. In the case of different stove designs, the minimum mean biochar yield （27.11%） was found from normal Anila stove. The pH of biochar is found to be significantly affected by the type of biomass （9.83 mean for corncob and coffee husk, 6.43 mean for sawdust）, heating time （9.19 mean for 90 min and 8.01 mean for 30 min） and stove type （9.52 mean for normal Anila and 8.01 mean for flangeless Anila continuous feeding type）. In fact, the type of biomass is observed to significantly affect the bulk density and surface area ofbiochar.展开更多
文摘This paper embraces the key points of unpolluted internally combusted engine emissions.Core objective is focused on the recent effort to improve compression ignition(CI)and spark ignition(SI)engine to have fuel⁃efficient and minimized pollutant emissions.There are many advanced internal combustion engines to overcome the challenges of conventional compression ignition engines of the high level of particulate matter(PM)and oxides of nitrogen emission.One of the latest options on which many researchers work recently is low⁃temperature combustion which studies the engine advancement and emission at the same time.This review focuses on the released emissions,incinerations and performances features of partially premixed charge ignition with different fuel blends like n⁃butanol⁃gasoline,gasoline⁃diesel,alcohol⁃diesel,and NG⁃diesel effect on partially premixed charge ignition(PPCI)engine combustion.Therefore,PPCI is a single or a dual fuel strategy in that a pre⁃mixed low or high reactive fuel(L/HRF)is directly injected into the engine.It is one of the best low⁃temperature combustion(LTC)strategies by which emissions are minimized while thermal efficiency is acceptable.The recent PPCI of various fuels and their effect are compared.Accordingly,the initial pilot injection can extend the operating load that is a problem in diesel engine;gasoline fuel displayed fewer soot releases when compared with diesel oil in all working situations.The additional inspiring outcome for this combustion approach can be directly controlled by using the start of injection timing(SOI),which is impossible with most other LTC concepts.The diesel PPCI can overcome the NOx⁃PM tradeoff but needs more EGR rates.Another problem of diesel engine PPCI is associated with its comparatively higher boiling point and relatively lower volatility,which made use of advanced injection with a great number of fuel challenges.Thus,diesel fuel is not the best candidate with the LRF to the PPCI engine setup.
文摘The developing world still largely depends on biomass, such as wood, animal dung and agricultural waste for domestic fuel sources that are typically burned in traditional stoves. Ethiopia has different biomass resource for biochar production, through pyrolysis cook stove co-producing biochar. Coffee husks are the major solid residues from the handling and processing of coffee in the study area. This study was to evaluate the biochar co-producing pyrolysis cook stove with respect to heat transfer through the bed and biochar yield. From allothermal type of pyrolysis cook stove, the stove design was selected for both the computational fluid dynamic （CFD） simulation and experimental measurements. ANSYS 14.5 was used for CFD simulation of the wood combustion. The production of biochar from coffee husk, corncob and sawdust at different heating times, bed and stove surface temperature were undertaken. Bulk density, pH and surface area of the biochar were measured. While good agreement between simulation and experimental result was obtained in the conduction phase during pyrolysis, deviation between the two on account of the effect of volatile gas in changing the temperature trend within the biomass bed was noticed. Within the biomass type, the maximum mean biochar yield （38.91%） was seen from coffee husk. In the case of different stove designs, the minimum mean biochar yield （27.11%） was found from normal Anila stove. The pH of biochar is found to be significantly affected by the type of biomass （9.83 mean for corncob and coffee husk, 6.43 mean for sawdust）, heating time （9.19 mean for 90 min and 8.01 mean for 30 min） and stove type （9.52 mean for normal Anila and 8.01 mean for flangeless Anila continuous feeding type）. In fact, the type of biomass is observed to significantly affect the bulk density and surface area ofbiochar.
