Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable, desulfurization sorbents capable of removing hydrogen sulfide from coal gasif...Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable, desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier gas to very low levels. As a sort of effective desufurizer, such as Fe2O3, ZnO and ZnFe2O4, it will endure strong reducing atmosphere in desulfurization process. The reduced degree of desufurizer can have an effect on its desulfurization reactivity. In this paper, Fe2O3, ZnO and ZnFe2O4 were synthesized by precipitation or co-precipitation at constant pH. After aging, washing and drying, the solids were calcined at 800℃. The reduction behaviors of sample were characterized by temperature-programmed reduction （TPR）. It is found that there are two reduction peaks for Fe2O3 in TPR, and whereas no reduction peaks for ZnO are found. The reduction process of ZnFe2O4 prepared by co-precipitation is different from that of Fe2O3. ZnFe2O4 is easier to be reduced than Fe2O3. The activation energy of reduction process for Fe2O3 and ZnFe2O4 is obtained at different reduction periods.展开更多
In this research project,copper and stainless steel were connected by two laser welding methods:straight seam welding and swing welding.Then,electronic tensile test machine,X-ray diffractometer,scanning electron micro...In this research project,copper and stainless steel were connected by two laser welding methods:straight seam welding and swing welding.Then,electronic tensile test machine,X-ray diffractometer,scanning electron microscope and metallographic microscope were used to analyze the tensile properties,macroscopic and microscopic structure morphology and phase of the welded joint.Based on the experimental results,we determined that the strength of the straight seam welded joint was higher.Because of the intermetallic compound near the weld in the swing welding process,it leads to stress concentration,crack cracking and strength reduction.In addition,the oscillating laser beam also leads to the disorderly direction of columnar crystal and coarse structure,which makes the joint strength decrease.展开更多
High temperature and pressure are the main challenges faced in the exploration of deep earth sciences.In order to ensure the safe drilling of high-temperature and high-pressure wells,a thick-walled simulated wellbore ...High temperature and pressure are the main challenges faced in the exploration of deep earth sciences.In order to ensure the safe drilling of high-temperature and high-pressure wells,a thick-walled simulated wellbore device is proposed and its heat transfer characteristics are studied according to the test requirements of pressure bearing exceeds 25 MPa and temperature exceeds 673.15 K.To investigate the dynamic heating process of the fluid within the cylinder,a mathematical model was developed to describe the coupled heat transfer mechanisms.This model incorporates the nonlinear properties of the fluid inside the cylinder.The results reveal that the temperature field distribution during the dynamic coupling heat transfer process is influenced by the electromagnetic induction current and the internal flow within the cylinder.During heating,the liquid transitions from a subcritical to a supercritical state.Buoyancy arising in the heating process affects the temperature distribution within the container and the formation of vortices.Incorporating a cooling system at the top of the container effectively maintains low-temperature operation in the sealing area.Additionally,the study shows that higher currents significantly increase both the final average liquid temperature and the cylinder wall temperature compared to the initial conditions.The proposed model and solution methodology provide a reliable approach for simulating fluid-structure coupled heat transfer in high-temperature,high-pressure well environments,offering a theoretical foundation for designing simulated wellbore heating systems.展开更多
The bifurcation solutions of resonant cases, including the main resonance, subharmonic resonance, superharmonic resonance and fractional resonance, are studied with the Liapunov-Schmidt method. The (α’,β’)-plane o...The bifurcation solutions of resonant cases, including the main resonance, subharmonic resonance, superharmonic resonance and fractional resonance, are studied with the Liapunov-Schmidt method. The (α’,β’)-plane of every resonant case divides into six open regions; all points inside any one of the six regions give topologically equivalent response diagrams. The boundary arcs separating these six regions are of two distinct types: five of them are of the normal codimension-1 and one is of infinite codimensions. The theoretical base of vibration, control of nonlinear systems is presented.展开更多
The building sector accounts for more than 40% of the global energy consumption. This consumption may be lowered by reducing building energy requirements and using renewable energy in building energy supply systems. S...The building sector accounts for more than 40% of the global energy consumption. This consumption may be lowered by reducing building energy requirements and using renewable energy in building energy supply systems. Solar air-conditioning systems(SACS) are a promising solution for the reduction of conventional energy in buildings. The storage, especially the cold storage, plays an important role in SACS for unstable solar irradiation. In this paper, we took the absorption refrigerating unit as an example, and the solar air-conditioning system of an office building in Beijing was simulated. The accuracy of this model was verified by comparing with the SACS operation data. Moreover, based on the simulation data, the cold storage capacity of the solar air-conditioning system in different climatic regions was studied. The cold storage capacities of SACS in 20 cities distributed in different climate regions were studied systematically. The results simulated by our proposed model will be beneficial to the SACS design, and will enlarge the application of SACS.展开更多
基金the Ministry of Science and Technology of China under the Grant No. G2005CB221203the Natural Science Foundation of China(20776092)
文摘Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable, desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier gas to very low levels. As a sort of effective desufurizer, such as Fe2O3, ZnO and ZnFe2O4, it will endure strong reducing atmosphere in desulfurization process. The reduced degree of desufurizer can have an effect on its desulfurization reactivity. In this paper, Fe2O3, ZnO and ZnFe2O4 were synthesized by precipitation or co-precipitation at constant pH. After aging, washing and drying, the solids were calcined at 800℃. The reduction behaviors of sample were characterized by temperature-programmed reduction （TPR）. It is found that there are two reduction peaks for Fe2O3 in TPR, and whereas no reduction peaks for ZnO are found. The reduction process of ZnFe2O4 prepared by co-precipitation is different from that of Fe2O3. ZnFe2O4 is easier to be reduced than Fe2O3. The activation energy of reduction process for Fe2O3 and ZnFe2O4 is obtained at different reduction periods.
基金Supported by the National Natural Science Foundation of China(51801057,51702091,12104140)the Natural Science Foundation of Hubei Province(2020CFB245)+2 种基金the Hubei Province Education Department Scientific Research Plan Guiding Project(B2017215,B2021260)the Research Start-up Funding of Hubei University of Education(19RC03,20RC09)the 2021 Science and Technology Development Plan of Henan Province(212102210336)。
文摘In this research project,copper and stainless steel were connected by two laser welding methods:straight seam welding and swing welding.Then,electronic tensile test machine,X-ray diffractometer,scanning electron microscope and metallographic microscope were used to analyze the tensile properties,macroscopic and microscopic structure morphology and phase of the welded joint.Based on the experimental results,we determined that the strength of the straight seam welded joint was higher.Because of the intermetallic compound near the weld in the swing welding process,it leads to stress concentration,crack cracking and strength reduction.In addition,the oscillating laser beam also leads to the disorderly direction of columnar crystal and coarse structure,which makes the joint strength decrease.
基金financially supported by the National Natural Science Foundation of China(52275159)the Natural Science Fund for Distinguished Young Scholar of Hubei Province(2022CFA059)。
文摘High temperature and pressure are the main challenges faced in the exploration of deep earth sciences.In order to ensure the safe drilling of high-temperature and high-pressure wells,a thick-walled simulated wellbore device is proposed and its heat transfer characteristics are studied according to the test requirements of pressure bearing exceeds 25 MPa and temperature exceeds 673.15 K.To investigate the dynamic heating process of the fluid within the cylinder,a mathematical model was developed to describe the coupled heat transfer mechanisms.This model incorporates the nonlinear properties of the fluid inside the cylinder.The results reveal that the temperature field distribution during the dynamic coupling heat transfer process is influenced by the electromagnetic induction current and the internal flow within the cylinder.During heating,the liquid transitions from a subcritical to a supercritical state.Buoyancy arising in the heating process affects the temperature distribution within the container and the formation of vortices.Incorporating a cooling system at the top of the container effectively maintains low-temperature operation in the sealing area.Additionally,the study shows that higher currents significantly increase both the final average liquid temperature and the cylinder wall temperature compared to the initial conditions.The proposed model and solution methodology provide a reliable approach for simulating fluid-structure coupled heat transfer in high-temperature,high-pressure well environments,offering a theoretical foundation for designing simulated wellbore heating systems.
基金Project supported by the National Natural Science Foundation of China.
文摘The bifurcation solutions of resonant cases, including the main resonance, subharmonic resonance, superharmonic resonance and fractional resonance, are studied with the Liapunov-Schmidt method. The (α’,β’)-plane of every resonant case divides into six open regions; all points inside any one of the six regions give topologically equivalent response diagrams. The boundary arcs separating these six regions are of two distinct types: five of them are of the normal codimension-1 and one is of infinite codimensions. The theoretical base of vibration, control of nonlinear systems is presented.
基金funded by the National Key R&D Program of China (No. 2017YFC0702600)
文摘The building sector accounts for more than 40% of the global energy consumption. This consumption may be lowered by reducing building energy requirements and using renewable energy in building energy supply systems. Solar air-conditioning systems(SACS) are a promising solution for the reduction of conventional energy in buildings. The storage, especially the cold storage, plays an important role in SACS for unstable solar irradiation. In this paper, we took the absorption refrigerating unit as an example, and the solar air-conditioning system of an office building in Beijing was simulated. The accuracy of this model was verified by comparing with the SACS operation data. Moreover, based on the simulation data, the cold storage capacity of the solar air-conditioning system in different climatic regions was studied. The cold storage capacities of SACS in 20 cities distributed in different climate regions were studied systematically. The results simulated by our proposed model will be beneficial to the SACS design, and will enlarge the application of SACS.
