A rapid, phenomenological model that predicts paniculate matter (PM) emissionof diesel engines is developed and formulated. The model is a chemical equilibrium compositionmodel, and is based on the formation mechanism...A rapid, phenomenological model that predicts paniculate matter (PM) emissionof diesel engines is developed and formulated. The model is a chemical equilibrium compositionmodel, and is based on the formation mechanisms of PM and unburned hydrocarbon (HC) emissions ofdiesel engines. It can evaluate the emission concentration of PM via the emission concentration ofHC. To validate the model, experiments are carried out in two research diesel engines. Comparisonsof the model results with the experimental data show good agreement. The model can be used toevaluate the concentration of PM emission of diesel engines under lack of PM measuring instruments.In addition, the model is useful for computer simulations of diesel engines, as well as electroniccontrol unit (ECU) designs for electronically controlled diesel engines.展开更多
Mixed crude palm oil （MCPO）, the mixture of palm fiber oil and palm kernel oil, has become of great interest as a renewable energy source. It can be easily extracted from whole dried palm fruits. In the present work...Mixed crude palm oil （MCPO）, the mixture of palm fiber oil and palm kernel oil, has become of great interest as a renewable energy source. It can be easily extracted from whole dried palm fruits. In the present work, the degummed, deacidified MCPO was blended in petroleum diesel at portions of 30% and 40% by volume and then tested in agricultural diesel engines for long term usage. The particulates from the exhaust of the engines were collected every 500 hr using a four-stage cascade air sampler. The 50% cut-off aerodynamic diameters for the first three stages were 10, 2.5 and 1μm, while the last stage collected all particles smaller than 1 μm. Sixteen particle bounded polycyclic aromatic hydrocarbons （PAHs） were analyzed using a high performance liquid chromatography. The results indicated that the size distribution of particulate matter was in the accmnulation mode and the pattern of total PAHs associated with fine-particles （〈 1 μm） showed a dominance of larger molecular weight PAHs （4--6 aromatic rings）, especially pyrene. The mass median diameter, PM and total PAH concentrations decreased when increasing the palm oil content, but increased when the running hours of the engine were increased. In addition, Commercial petroleum diesel （PB0） gave the highest value of carcinogenic potency equivalent （BaPeq） for all particle size ranges. As the palm oil was increased, the; BaPeq decreased gradually. Therefore the degununed-deacidified MCPO blends are recommended for diesel substitute.展开更多
In this study, the efforts to reduce NOx and particulate matter （PM） emissions from a diesel engine using both ethanol-selective catalytic reduction （SCR） of NOx over an Ag/Al2O3 catalyst and a biodiesel-ethanol-d...In this study, the efforts to reduce NOx and particulate matter （PM） emissions from a diesel engine using both ethanol-selective catalytic reduction （SCR） of NOx over an Ag/Al2O3 catalyst and a biodiesel-ethanol-diesel fuel blend （BE-diesel） on an engine bench test are discussed. Compared with diesel fuel, use of BE-diesel increased PM emissions by 14% due to the increase in the soluble organic fraction （SOF） of PM, but it greatly reduced the Bosch smoke number by 60%-80% according to the results from 13-mode test of European Stationary Cycle （ESC） test. The SCR catalyst was effective in NOx reduction by ethanol, and the NOx conversion was approximately 73%. Total hydrocarbons （THC） and CO emissions increased significantly during the SCR of NOx process. Two diesel oxidation catalyst （DOC） assemblies were used after Ag/Al2O3 converter to remove CO and HC. Different oxidation catalyst showed opposite effect on PM emission. The PM composition analysis revealed that the net effect of oxidation catalyst on total PM was an integrative effect on SOF reduction and sulfate formation of PM. The engine bench test results indicated that the combination of BE-diesel and a SCR catalyst assembly could provide benefits for NOx and PM emissions control even without using diesel particle filters （DPFs）.展开更多
Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation.The emission factor for nitrogen...Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation.The emission factor for nitrogen oxides is lower than what is typically found for marine gasoil but does not reach the tier III limit.The emissions of particulate matter are significantly lower than for fuel oils and similar to what is found for LNG engines.The main part of the particles can be found in the ultrafine range with the peak being at around 18 nm.About 93%of the particles are evaporated and absorbed when using a thermodenuder,and thus a large majority of the particles are volatile.Methanol is a potential future marine fuel that will reduce emissions of air pollutants and can be made as a biofuel to meet emission targets for greenhouse gases.展开更多
To explore the effect of the gas source flow rate on the actual diesel exhaust particulate matter（PM）, a test bench for diesel engine exhaust purification was constructed, using indirect nonthermal plasma technology...To explore the effect of the gas source flow rate on the actual diesel exhaust particulate matter（PM）, a test bench for diesel engine exhaust purification was constructed, using indirect nonthermal plasma technology. The effects of different gas source flow rates on the quantity concentration, composition, and apparent activation energy of PM were investigated, using an engine exhaust particle sizer and a thermo-gravimetric analyzer. The results show that when the gas source flow rate was large, not only the maximum peak quantity concentrations of particles had a large drop, but also the peak quantity concentrations shifted to smaller particle sizes from 100 nm to 80 nm. When the gas source flow rate was 10L min^-1, the total quantity concentration greatly decreased where the removal rate of particles was 79.2%, and the variation of the different mode particle proportion was obvious. Non-thermal plasma（NTP） improved the oxidation ability of volatile matter as well as that of solid carbon. However, the NTP gas source rate had little effects on oxidation activity of volatile matter, while it strongly influenced the oxidation activity of solid carbon. Considering the quantity concentration and oxidation activity of particles, a gas source flow rate of 10L min^-1 was more appropriate for the purification of particles.展开更多
Animal fats biodiesel were manufactured and tested for its performance in the tractor engine and fuel adoptability in the field works. Four different fuels, three different content of biodiesel （BD20, BD50 and BD100...Animal fats biodiesel were manufactured and tested for its performance in the tractor engine and fuel adoptability in the field works. Four different fuels, three different content of biodiesel （BD20, BD50 and BD100） and light oil, were prepared and tested in the four strokes diesel engine. Power output, fuel consumption rate and exhaust gases of the four fuels in the diesel engine were compared and discussed. Power output of light oil engine was the greatest showing 5.3% difference between light oil and BDI00. But, almost no power difference between light oil engine and BD20 engine, light oil engine produced 0.37% more power than BD20 engine superior to better power than BD20 engine. Less exhaust gases of CO2, CO, NOx and total hydrocarbon （THC） were produced from animal fats biodiesel than light oil, which confirmed that biodiesel is environmental friendly fuel. For fuel adoptability in the tractor, biodiesel engine tractor showed its fuel competitiveness comparing with light oil for tractor works in the paddy field.展开更多
The effects of continuously regenerating diesel particulate filter （CRDPF） systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investiga...The effects of continuously regenerating diesel particulate filter （CRDPF） systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investigated in this study. Two CRDPF units （CRDPF-1 and CRDPF-2） with different specifications were separately retrofitted to the engine running with European steady-state cycle （ESC）. An electrical low pressure impactor （ELPI） was used for particle number-size distribution measurement and mass estimation. The conversion/reduction rate （RcR） of hydrocarbons （HC） and carbon monoxide （CO） across CRDPF-1 was 83% and 96.3%, respectively. Similarly, the RCR of HC and CO and across CRDPF-2 was 91.8% and 99.1%, respectively. The number concentration of particles and their concentration peaks; nuclei mode, accumulation mode and total particles; and particle mass were highly reduced with the CRDPF units. The nuclei mode particles at downstream of CRDPF-1 and CRDPF-2 decreased by 99.9% to 100% and 97.8% to 99.8% respectively; and the particle mass reduced by 73% to 92.2% and 35.3% to 72.4%, respectively, depending on the engine conditions. In addition, nuclei mode particles increased with the increasing of engine speed due to the heterogeneous nucleation initiated by the higher exhaust temperature, while accumulation mode particles were higher at higher loads due to the decrease in the air-to-fuel ratio （A/F） at higher loads.展开更多
Experiments were conducted on a four-cylinder direct-injection diesel engine with 10% and 20% of the engine load taken up by fumigation ethanol injected into the air intake of each cylinder, to investigate the gaseous...Experiments were conducted on a four-cylinder direct-injection diesel engine with 10% and 20% of the engine load taken up by fumigation ethanol injected into the air intake of each cylinder, to investigate the gaseous, particulate mass (PM) emissions, and number concentration and size distribution of the engine under five engine loads at the maximum torque engine speed of 1800 r/min. The experimental results show that at low engine loads, the brake thermal efficiency (BTE) decreases with increase in fumigation ethanol; but at high engine loads, the BTE is not significantly changed by fumigation ethanol. Fumigation ethanol can effectively decrease in brake specific nitrogen oxides (BSNOx), particulate mass and number emissions but significantly increase in brake specific hydrocarbon (BSHC), brake specific carbon monoxide (BSCO) and proportion of BSNO/BSNO2. Also, the geometrical mean diameter of the particles (GMD) increases with increase in engine load but the diameter is not changed by fumigation ethanol in all cases.展开更多
基金This project is supported by National Basic Research Programme of China (No.2001CB209205).
文摘A rapid, phenomenological model that predicts paniculate matter (PM) emissionof diesel engines is developed and formulated. The model is a chemical equilibrium compositionmodel, and is based on the formation mechanisms of PM and unburned hydrocarbon (HC) emissions ofdiesel engines. It can evaluate the emission concentration of PM via the emission concentration ofHC. To validate the model, experiments are carried out in two research diesel engines. Comparisonsof the model results with the experimental data show good agreement. The model can be used toevaluate the concentration of PM emission of diesel engines under lack of PM measuring instruments.In addition, the model is useful for computer simulations of diesel engines, as well as electroniccontrol unit (ECU) designs for electronically controlled diesel engines.
基金supports from Prince of Songkla University(an annual research grant for fiscal years 2008-2010),the Center of Excellence for Innovation in Chemistry(PERCH-CIC),Office of the Higher Education Commission,Ministry of Education,Thailandthe Chaipattana Foundation under the support of the King of Thailand
文摘Mixed crude palm oil （MCPO）, the mixture of palm fiber oil and palm kernel oil, has become of great interest as a renewable energy source. It can be easily extracted from whole dried palm fruits. In the present work, the degummed, deacidified MCPO was blended in petroleum diesel at portions of 30% and 40% by volume and then tested in agricultural diesel engines for long term usage. The particulates from the exhaust of the engines were collected every 500 hr using a four-stage cascade air sampler. The 50% cut-off aerodynamic diameters for the first three stages were 10, 2.5 and 1μm, while the last stage collected all particles smaller than 1 μm. Sixteen particle bounded polycyclic aromatic hydrocarbons （PAHs） were analyzed using a high performance liquid chromatography. The results indicated that the size distribution of particulate matter was in the accmnulation mode and the pattern of total PAHs associated with fine-particles （〈 1 μm） showed a dominance of larger molecular weight PAHs （4--6 aromatic rings）, especially pyrene. The mass median diameter, PM and total PAH concentrations decreased when increasing the palm oil content, but increased when the running hours of the engine were increased. In addition, Commercial petroleum diesel （PB0） gave the highest value of carcinogenic potency equivalent （BaPeq） for all particle size ranges. As the palm oil was increased, the; BaPeq decreased gradually. Therefore the degununed-deacidified MCPO blends are recommended for diesel substitute.
基金This work was supported by the National Natural Science Foundation of China （No. 20425722, 20621140004）；the Ministry of Science and Technology of China （No. 2006AA060304）.
文摘In this study, the efforts to reduce NOx and particulate matter （PM） emissions from a diesel engine using both ethanol-selective catalytic reduction （SCR） of NOx over an Ag/Al2O3 catalyst and a biodiesel-ethanol-diesel fuel blend （BE-diesel） on an engine bench test are discussed. Compared with diesel fuel, use of BE-diesel increased PM emissions by 14% due to the increase in the soluble organic fraction （SOF） of PM, but it greatly reduced the Bosch smoke number by 60%-80% according to the results from 13-mode test of European Stationary Cycle （ESC） test. The SCR catalyst was effective in NOx reduction by ethanol, and the NOx conversion was approximately 73%. Total hydrocarbons （THC） and CO emissions increased significantly during the SCR of NOx process. Two diesel oxidation catalyst （DOC） assemblies were used after Ag/Al2O3 converter to remove CO and HC. Different oxidation catalyst showed opposite effect on PM emission. The PM composition analysis revealed that the net effect of oxidation catalyst on total PM was an integrative effect on SOF reduction and sulfate formation of PM. The engine bench test results indicated that the combination of BE-diesel and a SCR catalyst assembly could provide benefits for NOx and PM emissions control even without using diesel particle filters （DPFs）.
文摘Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for a ferry during operation.The emission factor for nitrogen oxides is lower than what is typically found for marine gasoil but does not reach the tier III limit.The emissions of particulate matter are significantly lower than for fuel oils and similar to what is found for LNG engines.The main part of the particles can be found in the ultrafine range with the peak being at around 18 nm.About 93%of the particles are evaporated and absorbed when using a thermodenuder,and thus a large majority of the particles are volatile.Methanol is a potential future marine fuel that will reduce emissions of air pollutants and can be made as a biofuel to meet emission targets for greenhouse gases.
基金supported by National Natural Science Foundation of China(No.51676089)the major projects of natural science research in colleges and universities in Jiangsu Province(No.16KJA470002)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PADA)
文摘To explore the effect of the gas source flow rate on the actual diesel exhaust particulate matter（PM）, a test bench for diesel engine exhaust purification was constructed, using indirect nonthermal plasma technology. The effects of different gas source flow rates on the quantity concentration, composition, and apparent activation energy of PM were investigated, using an engine exhaust particle sizer and a thermo-gravimetric analyzer. The results show that when the gas source flow rate was large, not only the maximum peak quantity concentrations of particles had a large drop, but also the peak quantity concentrations shifted to smaller particle sizes from 100 nm to 80 nm. When the gas source flow rate was 10L min^-1, the total quantity concentration greatly decreased where the removal rate of particles was 79.2%, and the variation of the different mode particle proportion was obvious. Non-thermal plasma（NTP） improved the oxidation ability of volatile matter as well as that of solid carbon. However, the NTP gas source rate had little effects on oxidation activity of volatile matter, while it strongly influenced the oxidation activity of solid carbon. Considering the quantity concentration and oxidation activity of particles, a gas source flow rate of 10L min^-1 was more appropriate for the purification of particles.
文摘Animal fats biodiesel were manufactured and tested for its performance in the tractor engine and fuel adoptability in the field works. Four different fuels, three different content of biodiesel （BD20, BD50 and BD100） and light oil, were prepared and tested in the four strokes diesel engine. Power output, fuel consumption rate and exhaust gases of the four fuels in the diesel engine were compared and discussed. Power output of light oil engine was the greatest showing 5.3% difference between light oil and BDI00. But, almost no power difference between light oil engine and BD20 engine, light oil engine produced 0.37% more power than BD20 engine superior to better power than BD20 engine. Less exhaust gases of CO2, CO, NOx and total hydrocarbon （THC） were produced from animal fats biodiesel than light oil, which confirmed that biodiesel is environmental friendly fuel. For fuel adoptability in the tractor, biodiesel engine tractor showed its fuel competitiveness comparing with light oil for tractor works in the paddy field.
基金supported by the National Natural Science Foundation of China (No. 40805053)
文摘The effects of continuously regenerating diesel particulate filter （CRDPF） systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investigated in this study. Two CRDPF units （CRDPF-1 and CRDPF-2） with different specifications were separately retrofitted to the engine running with European steady-state cycle （ESC）. An electrical low pressure impactor （ELPI） was used for particle number-size distribution measurement and mass estimation. The conversion/reduction rate （RcR） of hydrocarbons （HC） and carbon monoxide （CO） across CRDPF-1 was 83% and 96.3%, respectively. Similarly, the RCR of HC and CO and across CRDPF-2 was 91.8% and 99.1%, respectively. The number concentration of particles and their concentration peaks; nuclei mode, accumulation mode and total particles; and particle mass were highly reduced with the CRDPF units. The nuclei mode particles at downstream of CRDPF-1 and CRDPF-2 decreased by 99.9% to 100% and 97.8% to 99.8% respectively; and the particle mass reduced by 73% to 92.2% and 35.3% to 72.4%, respectively, depending on the engine conditions. In addition, nuclei mode particles increased with the increasing of engine speed due to the heterogeneous nucleation initiated by the higher exhaust temperature, while accumulation mode particles were higher at higher loads due to the decrease in the air-to-fuel ratio （A/F） at higher loads.
基金supported by the National Natural Science Foundation of China (Grant No. 50876065)the Research Grants Council of the HongKong SAR (Project No. PolyU 5139/07E)
文摘Experiments were conducted on a four-cylinder direct-injection diesel engine with 10% and 20% of the engine load taken up by fumigation ethanol injected into the air intake of each cylinder, to investigate the gaseous, particulate mass (PM) emissions, and number concentration and size distribution of the engine under five engine loads at the maximum torque engine speed of 1800 r/min. The experimental results show that at low engine loads, the brake thermal efficiency (BTE) decreases with increase in fumigation ethanol; but at high engine loads, the BTE is not significantly changed by fumigation ethanol. Fumigation ethanol can effectively decrease in brake specific nitrogen oxides (BSNOx), particulate mass and number emissions but significantly increase in brake specific hydrocarbon (BSHC), brake specific carbon monoxide (BSCO) and proportion of BSNO/BSNO2. Also, the geometrical mean diameter of the particles (GMD) increases with increase in engine load but the diameter is not changed by fumigation ethanol in all cases.
