This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction betwee...This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction between various structural materials and molten salts.The apparatus enables accurate detection of every phase change during hightemperature experiments,including strong reaction processes like corrosion.Molten salts,such as chlorides or fluo⁃rides,together with the structure materials,are inserted into either quartz or boron nitride capillaries,where X-ray diffraction pattern can be continuously collected,as the samples are heated to high temperature.The replacement re⁃action,when molten ZnCl2 are etching Ti3AlC2,can be clearly observed through changes in diffraction peak intensity as well as expansion in c-axis lattice parameter of the hexagonal matrix,due to the larger atomic number and ionic ra⁃dius of Zn2+.Furthermore,we investigated the high-temperature corrosion process when GH3535 alloy is in FLiNaK molten salt,and can help to optimize its stability for potential applications in molten salt reactor.Additionally,this high temperature apparatus is fully compatible with the combined usage of X-ray diffraction and Raman technique,providing both bulk and surface structural information.This high temperature apparatus has been open to users and is extensively used at BL14B1 beamline of the Shanghai Synchrotron Radiation Facility.展开更多
The solution behavior, including solubility, reactivity and sedimentation, of ZnO and ZnS in a Na<sub>2</sub>CO<sub>3</sub>−NaCl molten salt used for Sb smelting was investigated in the tempera...The solution behavior, including solubility, reactivity and sedimentation, of ZnO and ZnS in a Na<sub>2</sub>CO<sub>3</sub>−NaCl molten salt used for Sb smelting was investigated in the temperature range of 700-1000 ºC. The saturated amount of dissolved ZnO in the molten salt remained constant at 0.02% and was unaffected by temperature; additionally, ZnO did not react with the molten salt. In contrast, the saturated amount of dissolved ZnS in the eutectic molten salt increased with increasing temperature, and the content of ZnS was 0.53% at 1000 ºC. In addition, ZnS reacted with Na<sub>2</sub>CO<sub>3</sub> above 900 ºC to give ZnO. The sedimentation rates of these three species in the molten salt followed the order of Sb>ZnS>ZnO. It was thus concluded that ZnO is an appropriate sulfur-fixing agent for low-temperature Sb smelting in a Na<sub>2</sub>CO<sub>3</sub>−NaCl molten medium, and that the optimal smelting temperature is below 900 ºC.展开更多
Based on the service characteristics of fuel elements for molten salt reactors,they need to have a high power density,resistance to coolant infiltration,and excellent thermodynamic properties.To solve the problem of t...Based on the service characteristics of fuel elements for molten salt reactors,they need to have a high power density,resistance to coolant infiltration,and excellent thermodynamic properties.To solve the problem of the graphite used in the fuel element for these reactors being susceptible to molten salt infiltration,carbon black(CB)was added to increase the density of the graphite,and a fuel element(TRISO(tri-structural isotropic)fuel particles were randomly distributed in the modified graphite matrix)was prepared by cold isostatic pressing process.An out-of-pile performance study shows that the densification and pore structure of the modified graphite matrix were improved,as was the resistance to molten salt infiltration.The median pore size of the modified graphite was reduced from 673 to 433 nm and the threshold pressure for molten salt(FLiBe,66%(molar fraction)LiF and 34%BeF_(2))infiltration was increased from 0.88 to 1.37 MPa.The isotropic CB made the graphite matrix less anisotropic,while its thermal conductivity and compressive strength were reduced due to the difficult graphitization of CB.Fuel elements containing 20%(volume fraction)TRISO particles were prepared.Numerical simulations show that the power and temperature distribution of the fuel were in line with the design requirements.The modified graphite matrix had a higher density,smaller pores,a lower anisotropy and a greater resistance to FLiBe infiltration.展开更多
针对稠油注汽系统高耗能、高碳排放的问题,开展适用于稠油注汽的电热熔盐储能注汽技术研究,以实现稠油绿色开发。利用Abaqus软件模拟方法和系统综合热效率评价方法对系统工况进行优化设计,并开展现场试验。研究表明:电热熔盐储能注汽技...针对稠油注汽系统高耗能、高碳排放的问题,开展适用于稠油注汽的电热熔盐储能注汽技术研究,以实现稠油绿色开发。利用Abaqus软件模拟方法和系统综合热效率评价方法对系统工况进行优化设计,并开展现场试验。研究表明:电热熔盐储能注汽技术通过消纳绿电/谷电替代燃烧化石能源生产稠油注汽用湿饱和蒸汽的技术可行;蒸汽预热系统的蒸汽流量随蒸汽压力变化波动范围小,有利于系统稳定运行,是电热熔盐储能注汽系统的优选预热工艺;电热熔盐储能注汽系统负荷率为60%~100%时,系统综合热效率为92.61%~94.34%,且系统综合热效率随系统运行负荷的增加而提升;系统综合热效率的试验值平均数比理论计算值平均数低0.44个百分点,偏差小;与现有燃气注汽锅炉相比,试验站年产蒸汽4.8×10^(4) t,替代天然气313×10^(4) m 3,CO_(2)减排6768 t。该技术可为稠油注汽系统实现绿色转型发展提供技术支撑和实践指导,系统综合热效率评价方法可用于指导工程设计。展开更多
基金CAS Photon Science Research Center for Carbon DioxideCAS President’s International Fellowship Initiative(2024PVA0097)+1 种基金National Key Research and Development Program of China(2017YFA0403000,2017YFA0402800)National Natural Science Foundation of China(U1932201,U1732121)。
文摘This study demonstrates the design and application of a novel high temperature rotatory apparatus for insitu synchrotron X-ray diffraction studies of molten salts,facilitating investigation into the interaction between various structural materials and molten salts.The apparatus enables accurate detection of every phase change during hightemperature experiments,including strong reaction processes like corrosion.Molten salts,such as chlorides or fluo⁃rides,together with the structure materials,are inserted into either quartz or boron nitride capillaries,where X-ray diffraction pattern can be continuously collected,as the samples are heated to high temperature.The replacement re⁃action,when molten ZnCl2 are etching Ti3AlC2,can be clearly observed through changes in diffraction peak intensity as well as expansion in c-axis lattice parameter of the hexagonal matrix,due to the larger atomic number and ionic ra⁃dius of Zn2+.Furthermore,we investigated the high-temperature corrosion process when GH3535 alloy is in FLiNaK molten salt,and can help to optimize its stability for potential applications in molten salt reactor.Additionally,this high temperature apparatus is fully compatible with the combined usage of X-ray diffraction and Raman technique,providing both bulk and surface structural information.This high temperature apparatus has been open to users and is extensively used at BL14B1 beamline of the Shanghai Synchrotron Radiation Facility.
基金Projects(51104128,51234009)supported by the National Natural Science Foundation of China
文摘The solution behavior, including solubility, reactivity and sedimentation, of ZnO and ZnS in a Na<sub>2</sub>CO<sub>3</sub>−NaCl molten salt used for Sb smelting was investigated in the temperature range of 700-1000 ºC. The saturated amount of dissolved ZnO in the molten salt remained constant at 0.02% and was unaffected by temperature; additionally, ZnO did not react with the molten salt. In contrast, the saturated amount of dissolved ZnS in the eutectic molten salt increased with increasing temperature, and the content of ZnS was 0.53% at 1000 ºC. In addition, ZnS reacted with Na<sub>2</sub>CO<sub>3</sub> above 900 ºC to give ZnO. The sedimentation rates of these three species in the molten salt followed the order of Sb>ZnS>ZnO. It was thus concluded that ZnO is an appropriate sulfur-fixing agent for low-temperature Sb smelting in a Na<sub>2</sub>CO<sub>3</sub>−NaCl molten medium, and that the optimal smelting temperature is below 900 ºC.
文摘Based on the service characteristics of fuel elements for molten salt reactors,they need to have a high power density,resistance to coolant infiltration,and excellent thermodynamic properties.To solve the problem of the graphite used in the fuel element for these reactors being susceptible to molten salt infiltration,carbon black(CB)was added to increase the density of the graphite,and a fuel element(TRISO(tri-structural isotropic)fuel particles were randomly distributed in the modified graphite matrix)was prepared by cold isostatic pressing process.An out-of-pile performance study shows that the densification and pore structure of the modified graphite matrix were improved,as was the resistance to molten salt infiltration.The median pore size of the modified graphite was reduced from 673 to 433 nm and the threshold pressure for molten salt(FLiBe,66%(molar fraction)LiF and 34%BeF_(2))infiltration was increased from 0.88 to 1.37 MPa.The isotropic CB made the graphite matrix less anisotropic,while its thermal conductivity and compressive strength were reduced due to the difficult graphitization of CB.Fuel elements containing 20%(volume fraction)TRISO particles were prepared.Numerical simulations show that the power and temperature distribution of the fuel were in line with the design requirements.The modified graphite matrix had a higher density,smaller pores,a lower anisotropy and a greater resistance to FLiBe infiltration.
文摘针对稠油注汽系统高耗能、高碳排放的问题,开展适用于稠油注汽的电热熔盐储能注汽技术研究,以实现稠油绿色开发。利用Abaqus软件模拟方法和系统综合热效率评价方法对系统工况进行优化设计,并开展现场试验。研究表明:电热熔盐储能注汽技术通过消纳绿电/谷电替代燃烧化石能源生产稠油注汽用湿饱和蒸汽的技术可行;蒸汽预热系统的蒸汽流量随蒸汽压力变化波动范围小,有利于系统稳定运行,是电热熔盐储能注汽系统的优选预热工艺;电热熔盐储能注汽系统负荷率为60%~100%时,系统综合热效率为92.61%~94.34%,且系统综合热效率随系统运行负荷的增加而提升;系统综合热效率的试验值平均数比理论计算值平均数低0.44个百分点,偏差小;与现有燃气注汽锅炉相比,试验站年产蒸汽4.8×10^(4) t,替代天然气313×10^(4) m 3,CO_(2)减排6768 t。该技术可为稠油注汽系统实现绿色转型发展提供技术支撑和实践指导,系统综合热效率评价方法可用于指导工程设计。
