Diesel particulate matter(DPM) is considered carcinogenic after prolonged exposure. With more dieselpowered equipment used in underground mines, miners' exposure to DPM has become an increasing concern. This paper...Diesel particulate matter(DPM) is considered carcinogenic after prolonged exposure. With more dieselpowered equipment used in underground mines, miners' exposure to DPM has become an increasing concern. This paper used computational fluid dynamics(CFD) method to study DPM distribution based on an experiment conducted by the Diesel Emissions Evaluation Program(DEEP) in Canada. Twenty-four cases were simulated where the emissions from both truck and load-haul-dumps(LHDs) were examined.Each vehicle was placed in two stream wise locations, and the vehicles were oriented either facing or with the rear end toward the main fresh airflow. A species transport model with buoyancy effect was then used to examine the DPM dispersion pattern. High DPM regions were identified downstream,around, and even upstream of diesel engines. This can provide guidelines for good working practices and selection of diesel emission reduction technologies underground.展开更多
In the practice of petroleum industry, adding cold flow improver （CFI） to lower the fuel＇s cold filter plugging point （CFPP） is an effective and economic way for improving the cold flow performance of diesel fuel...In the practice of petroleum industry, adding cold flow improver （CFI） to lower the fuel＇s cold filter plugging point （CFPP） is an effective and economic way for improving the cold flow performance of diesel fuel. This paper described the synthesis and evaluation of the performance of dibehenyl fumarate-vinyl acetate （FV） copolymer for improving the cold flow performance of the tested diesel fuels. The carbon distribution in n-alkanes of the tested diesel samples were analyzed by gas phase chromatography. The structure of the copolymer was confirmed by the 1H NMR spectroscopy. The wax crystals morphologies with and without adding the FV additive were investigated by means of polarizing microscope. The test results indicated that the FV additive could depress CFPP of the tested diesel samples by 2℃ and 4℃, respectively, when dosage of the additive was 0.08 m%. The additive can modify the size and shape of the wax crystals and inhibit the formation of larger wax crystal lattices.展开更多
The computational fluid dynamics(CFD) code, FLUENT, was used to simulate the liquid-phase FCC diesel hydrotreating tubular reactor with a ceramic membrane tube dispenser. The chemical reaction and reaction heat were a...The computational fluid dynamics(CFD) code, FLUENT, was used to simulate the liquid-phase FCC diesel hydrotreating tubular reactor with a ceramic membrane tube dispenser. The chemical reaction and reaction heat were added to the model by user-defined function(UDF), showing the distribution of temperature and content of sulfides, nitrides, bicyclic aromatics and monocyclic aromatics in different parts of the reaction bed. When the pressure was 6.5 MPa, the amount of mixing hydrogen was 0.84%(m), the space velocity was 2 h-1 and the inlet temperature was 633 K, the temperature reached a maximum at a height of 0.15 m, and the range of radial temperature reached its maximum(2.5 K) at a height of 0.15 m. It indicated that the proper ratio of height to diameter of catalyst bed in the tubular reactor was 5-6. The increase of inlet temperature, the mixing hydrogen and the decrease of space velocity led to the decrease in the content of bicyclic aromatics, sulfides and nitrides, and the increase in monocyclic aromatics content, while the high temperature increased. The results were in good agreement with experimental data, indicating to the high accuracy of the model.展开更多
基金financial support provided by the Western US Mining Safety and Health Training & Translation Center by the National Institute for Occupational Safety and Health (NIOSH) (Grant No. 1 R25 OH008319)
文摘Diesel particulate matter(DPM) is considered carcinogenic after prolonged exposure. With more dieselpowered equipment used in underground mines, miners' exposure to DPM has become an increasing concern. This paper used computational fluid dynamics(CFD) method to study DPM distribution based on an experiment conducted by the Diesel Emissions Evaluation Program(DEEP) in Canada. Twenty-four cases were simulated where the emissions from both truck and load-haul-dumps(LHDs) were examined.Each vehicle was placed in two stream wise locations, and the vehicles were oriented either facing or with the rear end toward the main fresh airflow. A species transport model with buoyancy effect was then used to examine the DPM dispersion pattern. High DPM regions were identified downstream,around, and even upstream of diesel engines. This can provide guidelines for good working practices and selection of diesel emission reduction technologies underground.
基金supported by the Basic Research Program of the State Key Laboratory of Heavy Oil Processing(200310),China University of Petroleum,Beijing,China.
文摘In the practice of petroleum industry, adding cold flow improver （CFI） to lower the fuel＇s cold filter plugging point （CFPP） is an effective and economic way for improving the cold flow performance of diesel fuel. This paper described the synthesis and evaluation of the performance of dibehenyl fumarate-vinyl acetate （FV） copolymer for improving the cold flow performance of the tested diesel fuels. The carbon distribution in n-alkanes of the tested diesel samples were analyzed by gas phase chromatography. The structure of the copolymer was confirmed by the 1H NMR spectroscopy. The wax crystals morphologies with and without adding the FV additive were investigated by means of polarizing microscope. The test results indicated that the FV additive could depress CFPP of the tested diesel samples by 2℃ and 4℃, respectively, when dosage of the additive was 0.08 m%. The additive can modify the size and shape of the wax crystals and inhibit the formation of larger wax crystal lattices.
文摘The computational fluid dynamics(CFD) code, FLUENT, was used to simulate the liquid-phase FCC diesel hydrotreating tubular reactor with a ceramic membrane tube dispenser. The chemical reaction and reaction heat were added to the model by user-defined function(UDF), showing the distribution of temperature and content of sulfides, nitrides, bicyclic aromatics and monocyclic aromatics in different parts of the reaction bed. When the pressure was 6.5 MPa, the amount of mixing hydrogen was 0.84%(m), the space velocity was 2 h-1 and the inlet temperature was 633 K, the temperature reached a maximum at a height of 0.15 m, and the range of radial temperature reached its maximum(2.5 K) at a height of 0.15 m. It indicated that the proper ratio of height to diameter of catalyst bed in the tubular reactor was 5-6. The increase of inlet temperature, the mixing hydrogen and the decrease of space velocity led to the decrease in the content of bicyclic aromatics, sulfides and nitrides, and the increase in monocyclic aromatics content, while the high temperature increased. The results were in good agreement with experimental data, indicating to the high accuracy of the model.
