The oxidation induration and reduction swelling behavior of the chromium-bearing vanadium titanomagnetite pellets (CVTP) with B2O3 addition were investigated. Besides, the reduction swelling index (RSI) and compressiv...The oxidation induration and reduction swelling behavior of the chromium-bearing vanadium titanomagnetite pellets (CVTP) with B2O3 addition were investigated. Besides, the reduction swelling index (RSI) and compressive strength (CS) of the reduced CVTP were also examined using the simulated coke oven gas (COG). The results suggested that the CS of CVTP was increased from 2448 to 3819.2 N, while the porosity of CVTP was decreased from 14.86% to 10.03% with the increase in B2O3 addition amounts. Moreover, the B2O3 mainly existed in the forms of TiB0.024O2 and Fe3BO5 in both CVTP and the reduced CVTP. Specifically, the CS of the reduced CVTP was elevated from 901 to 956.2 N, while the RSI was reduced from 5.87% to 3.81% as the B2O3 addition amounts were increased. Taken together, B2O3 addition would facilitate the aggregation and diffusion of metallic iron particles, which contributed to reducing the formation of metal iron whiskers and weakening the reduction swelling behavior.展开更多
The hierarchical BiOClxBr1–x was synthesized by a simple solvothermal method. The samples were characterized by X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, UV-visible diffuse ref...The hierarchical BiOClxBr1–x was synthesized by a simple solvothermal method. The samples were characterized by X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, UV-visible diffuse reflectance spectroscopy （UV-vis DRS） and Brunauer-Emmett-Teller adsorption method. Compared to pure BiOCl or BiOBr, the BiOClxBr1–x solid solution has enhanced photocatalytic degradation activity for rhodamine B. This phenomenon can be explained to the hierarchical structure, lager specific surface area and appropriate energy gap of the obtained BiOClxBr1–x solid solution. The renewability and stability of photocatalyst were determinated and a possible mechanism of photocatalytic degradation was also proposed.展开更多
The dimensions and the materials type limit the performance of fuel cell. The increase of the temperature in electrodes and electrolyte of the cell,is due to the over potential of activation (transfer of load),the ove...The dimensions and the materials type limit the performance of fuel cell. The increase of the temperature in electrodes and electrolyte of the cell,is due to the over potential of activation (transfer of load),the over potential Ohmic (resistance of polarization),the over potential of reaction (heat released by the chemical reaction) and the over potential of diffusion. In this paper,we studied the thermo-electrical performance of an intermediate temperature solid oxide fuel cell (IT-SOFC) with electrode supported. The aim of this work is to study this increasing temperature of a single cell of an IT-SOFC under the influence of the following parameters: heat sources,functioning temperature and voltages of the cell,geometric configuration and materials type. The equation of energy in one dimension is numerically resolved by using the method of finite volumes. A computing program (FORTRAN) is developed locally for this purpose in order to obtain fields of temperature in every element of the cell.展开更多
The effective conductivity （aeff） of solid oxide fuel cell （SOFC） electrode is an important parameter for predicting the ohmic loss in SOFC. This paper investigates the effective conductivity of SOFC electrodes re...The effective conductivity （aeff） of solid oxide fuel cell （SOFC） electrode is an important parameter for predicting the ohmic loss in SOFC. This paper investigates the effective conductivity of SOFC electrodes recon- structed numerically by packing spherical particles in a computational domain, followed by a dilation process to simulate the sintering procedure. The effects of various parameters on the effective conductivity of the electrodes are investigated, including material composition, porosity, particle size and contact angle. Results show that the effective conductivity ratio （aeff/ao） of the computed con- ducting phase is mainly affected by its total volume frac- tion （VF） in electrode （including the porosity）. The effective conductivity can be improved by increasing the VF, electrode particle size or the contact angle between electrode particles. Based on the numerical results, the conventional percolation model for the calculation of O＇eft is improved by adjusting the Bruggeman factor from 1.5 to 2.7. The results are useful for understanding the microstructure properties of SOFC composite electrode and for subsequent electrode optimization.展开更多
基金Projects(51674084,51174051,51574082)supported by the National Natural Science Foundation of China
文摘The oxidation induration and reduction swelling behavior of the chromium-bearing vanadium titanomagnetite pellets (CVTP) with B2O3 addition were investigated. Besides, the reduction swelling index (RSI) and compressive strength (CS) of the reduced CVTP were also examined using the simulated coke oven gas (COG). The results suggested that the CS of CVTP was increased from 2448 to 3819.2 N, while the porosity of CVTP was decreased from 14.86% to 10.03% with the increase in B2O3 addition amounts. Moreover, the B2O3 mainly existed in the forms of TiB0.024O2 and Fe3BO5 in both CVTP and the reduced CVTP. Specifically, the CS of the reduced CVTP was elevated from 901 to 956.2 N, while the RSI was reduced from 5.87% to 3.81% as the B2O3 addition amounts were increased. Taken together, B2O3 addition would facilitate the aggregation and diffusion of metallic iron particles, which contributed to reducing the formation of metal iron whiskers and weakening the reduction swelling behavior.
基金Project(2016TP1007)supported by the Hunan Provincial Science and Technology Plan Project,China
文摘The hierarchical BiOClxBr1–x was synthesized by a simple solvothermal method. The samples were characterized by X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, UV-visible diffuse reflectance spectroscopy （UV-vis DRS） and Brunauer-Emmett-Teller adsorption method. Compared to pure BiOCl or BiOBr, the BiOClxBr1–x solid solution has enhanced photocatalytic degradation activity for rhodamine B. This phenomenon can be explained to the hierarchical structure, lager specific surface area and appropriate energy gap of the obtained BiOClxBr1–x solid solution. The renewability and stability of photocatalyst were determinated and a possible mechanism of photocatalytic degradation was also proposed.
文摘The dimensions and the materials type limit the performance of fuel cell. The increase of the temperature in electrodes and electrolyte of the cell,is due to the over potential of activation (transfer of load),the over potential Ohmic (resistance of polarization),the over potential of reaction (heat released by the chemical reaction) and the over potential of diffusion. In this paper,we studied the thermo-electrical performance of an intermediate temperature solid oxide fuel cell (IT-SOFC) with electrode supported. The aim of this work is to study this increasing temperature of a single cell of an IT-SOFC under the influence of the following parameters: heat sources,functioning temperature and voltages of the cell,geometric configuration and materials type. The equation of energy in one dimension is numerically resolved by using the method of finite volumes. A computing program (FORTRAN) is developed locally for this purpose in order to obtain fields of temperature in every element of the cell.
基金supported by a grant from Research Grant CouncilUniversity Grants CommitteeHong Kong SAR(Poly U 152127/14E)
文摘The effective conductivity （aeff） of solid oxide fuel cell （SOFC） electrode is an important parameter for predicting the ohmic loss in SOFC. This paper investigates the effective conductivity of SOFC electrodes recon- structed numerically by packing spherical particles in a computational domain, followed by a dilation process to simulate the sintering procedure. The effects of various parameters on the effective conductivity of the electrodes are investigated, including material composition, porosity, particle size and contact angle. Results show that the effective conductivity ratio （aeff/ao） of the computed con- ducting phase is mainly affected by its total volume frac- tion （VF） in electrode （including the porosity）. The effective conductivity can be improved by increasing the VF, electrode particle size or the contact angle between electrode particles. Based on the numerical results, the conventional percolation model for the calculation of O＇eft is improved by adjusting the Bruggeman factor from 1.5 to 2.7. The results are useful for understanding the microstructure properties of SOFC composite electrode and for subsequent electrode optimization.
