Kinetic regularities of 4-phenyl-o-tolunitrile ammoxidation on V-Sb-Bi-Zr/γ-Al2O3 oxide catalyst in the temperature interval 633 - 673 K have been studied. It has been established that rates of conversion of 4-phenyl...Kinetic regularities of 4-phenyl-o-tolunitrile ammoxidation on V-Sb-Bi-Zr/γ-Al2O3 oxide catalyst in the temperature interval 633 - 673 K have been studied. It has been established that rates of conversion of 4-phenyl-o-tolu- nitrile into the aimed 4-phenylphthalonitrile and CO2 are described by half-order equation on concentration of substratum and to be independent of the oxygen and ammonia partial pressures. It has been revealed that formation of 4-phenylphthalimide from byproducts is due to hydrolysis of 4-phenylphthalonitrile;carbon dioxide is produced by oxidation of 4-phenyl-o-tolunitrile and decarboxylation of 4-phenylphthalimide, and 4-phenylben- zonitrile is produced from 4-phenyl-o-tolunitrile and 4-phenylphthalimide.展开更多
MnSAPO-34 molecular sieves were synthesized by vapor-phase transport （VPT） method using triethylamine （Et3N） as a structure directing agent （SDA）, and were characterized by XRD, BET, SEM, UV-Vis, FT-IR, and TG a...MnSAPO-34 molecular sieves were synthesized by vapor-phase transport （VPT） method using triethylamine （Et3N） as a structure directing agent （SDA）, and were characterized by XRD, BET, SEM, UV-Vis, FT-IR, and TG analy- ses. The influence of the zeolite crystallization conditions and the dry-gel composition were investigated. The results showed that the synthesis conditions had an effect on the crystalline phase. Pure MnSAPO-34 had been obtained when it was crystallized at 140 C for 18 hours. The ratio of MnO/A1203 in the starting gel ranging from 0.1 to 0.2 resulted in pure MnSAPO-34 with a CHA topology. Beyond this scope, MnSAPO-5 with an AFI topology structure was obtained as an impurity substance. UV-Vis spectroscopy and FT-IR spectroscopy study indicated that manganese was incorporated into the framework of the molecular sieve. The catalytic performance of MnSAPO-34 molecular sieve was tested by ketalization reaction of l, 2-propanediol with cyclohexanone. High yield of cyclohexanone-1, 2-propanediol ketal was obtained.展开更多
Vapor-phase nitration of benzene over solid acid catalyst is expected to be a clean process with no sulfuric acid waste. We investigated this process over solid acidic catalysts utilizing diluted nitric acid (60-70%)...Vapor-phase nitration of benzene over solid acid catalyst is expected to be a clean process with no sulfuric acid waste. We investigated this process over solid acidic catalysts utilizing diluted nitric acid (60-70%) as nitrating agent, and found that supported sulfuric acid catalyst exhibited a very high catalytic activity. Under the conditions of reaction temperature 160-170℃, space velocity (SV) 1200 h-1, the yield and the space-time yield (STY) of nitrobenzene (NB) based on HNO3 were more than 98% and 0.75 kg穔gcat-1穐-1 over 10% H2SO4/SiO2 (by weight) catalyst respectively.展开更多
A stable δ- and β-bismuth trioxide was prepared at room temperature by vacuum vapor-phase oxidation. The average crystal size of products was 14.6 nm (by XRD), the d(0.5) value was in the range from 62 nm to 69 nm, ...A stable δ- and β-bismuth trioxide was prepared at room temperature by vacuum vapor-phase oxidation. The average crystal size of products was 14.6 nm (by XRD), the d(0.5) value was in the range from 62 nm to 69 nm, and geometric standard deviation(GSD) was from 1.42 to 1.64. The results show that δ-Bi2O3 is formed when quenching rates is rapid and β-Bi2O3 is formed when it is slow. The size of grains increases with rising reaction temperature, flow rate of carrier gas, residual pressure of system and longer growing time of grains.展开更多
With many merits such as facile synthesis,economy,and relatively high theoretical capacity,Prussian blue analogs(PBAs)are considered promising cathode materials for sodium-ion batteries(SIBs).However,their practical a...With many merits such as facile synthesis,economy,and relatively high theoretical capacity,Prussian blue analogs(PBAs)are considered promising cathode materials for sodium-ion batteries(SIBs).However,their practical applications still suffer from a low actual specific capacity and inferior stability owing to the imperfect crystallinity,irreversible phase transition,and low intrinsic conductivity.Herein,a surface-modification technique for vapor-phase molecular self-assembly was developed to prepare Fe-based PBAs,specifically sodium iron hexacyanoferrate(NaFeHCF),with a uniform conductive polymer protective layer of polypyrrole(PPy)on the surface,resulting in NaFeHCF@PPy.The incorporation of a PPy protective layer not only improves the electronic conductivity of NaFeHCF@PPy,but also effectively mitigates the dissolution of Fe-ions during cycling.Specifically,this advanced vapor-phase technique avoids Fe^(2+)oxidation and Na^(+)loss during liquid-phase surface modification.The NaFeHCF@PPy exhibited a remarkably enhanced cycling performance,with capacity retentions of 85.6%and 69.1%over 500 and 1000 cycles,respectively,at 200 mA/g,along with a superior rate performance up to 5 A/g(fast kinetics).Additionally,by adopting this strategy for Mn-based PBAs(NaMnHCF@PPy),we further demonstrated the universality of this method for PBA cathodes in SIBs.展开更多
Hypercrosslinked polymers(HCPs)with large surface areas,high intrinsic porosities and low production costs may be available platforms for iodine capture.However,the lack of iodine-philicity binding sites limits their ...Hypercrosslinked polymers(HCPs)with large surface areas,high intrinsic porosities and low production costs may be available platforms for iodine capture.However,the lack of iodine-philicity binding sites limits their adsorption capacity.Here we use vapor-phase postsynthetic amination strategy to introduce electron-donating amino groups into the prefabricated HCPs for enhancing their iodine capture performance.Through simple vapor-phase exposure,the halogen-containing HCPs can be grafted by amines through nucleophilic substitution toward chloro groups.Combining with the abundant amino groups and high porosities,the amino-functionalized porous polymers show substantially increased iodine adsorption capacity,about 221%as that of original one,accompanied by excellent recyclability.Mechanism investigations reveal the key roles of the electron-donor amino groups andπ-conjugated benzene rings along with structure characteristics of porous polymer frameworks in iodine capture.Moreover,this vapor-phase amination strategy shows good generality and can be extended to various amines,e.g.,ethylenediamine,1,3-diaminopropane and diethylenetriamine.Our work proves that this simple vapor-phase postsynthetic functionalization strategy may be applied in other porous polymers with wide application prospects in adsorption,separation and storage.展开更多
Developing efficient and stable zeolites for vapor-phase Beckmann rearrangement of cyclohexanone oxime is still a great challenge to realizeε-caprolactam(CPL)green production.In this work,the hierarchical porous sili...Developing efficient and stable zeolites for vapor-phase Beckmann rearrangement of cyclohexanone oxime is still a great challenge to realizeε-caprolactam(CPL)green production.In this work,the hierarchical porous silicalite-1 zeolites with multiple hollow structure(S-1-M)are explored by in-situ desilication−recrystallization post-treatment of spongy highway-like zeolites(S-1-S),which are synthesized through silanization synthesis of conventional bulky silicalite-1(S-1).Compared to S-1,S-1-M achieves superior catalytic performance,with improving the CPL selectivity from 85.7%to 94.1%and prolonging the catalyst lifetime from 74 to 126 h at a weight hourly space velocity(WHSV)of 6 h^(−1).Comprehensive physiochemical studies demonstrate that the highly dispersed intracrystalline cavities within S-1-M endow greater mass diffusion and better quasi acidity inducing by the enhanced H-bonds among abundant H-bonded silanols,which is cooperatively responsible for its superior catalytic performance.展开更多
Electrocatalytic synthesis of value-added chemicals is attracting significant research attention owing to its mild reaction conditions, environmental benignity, and potentially scalable application to organic syntheti...Electrocatalytic synthesis of value-added chemicals is attracting significant research attention owing to its mild reaction conditions, environmental benignity, and potentially scalable application to organic synthetic chemistry. Herein, we report the preparation of a single-crystalline NiS2 nanostructure film of N 50 nm thickness grown directly on a carbon fiber doth （NiSJCFC） by a facile vapor-phase hydrothermal （VPH） method. NiSJCFC as an electrocatalyst exhibits activity for both the oxygen evolution reaction （OER） and the hydrogen evolution reaction （HER） in alkaline media. Furthermore, a series of alcohols （2-propanol, 2-butanol, 2-pentanol, and cyclohexanol） were electrocatalytically converted to the corresponding ketones with high selectivity, efficienc and durability using the NiSJCFC electrode in alkaline media. In the presence of 0.45 M alcohol, a remarkably decreased overpotential （- 150 mV, vs. RHE） at the NiS2/CFC anode compared with that for water oxidation to generate O2, i.e., the OER, in alkaline media leads to significantly improved H2 generation. For instance, the H2 generation rate in the presence of 0.45 M 2-propanol is almost 1.2-times of that obtained for pure water splitting, but in a system that employs an applied voltage at least 280 mV lower than that required for water splitting to achieve the same current density （20 mA-crn-2）. Thus, our results demonstrate the applicability of our bifunctional non-precious-metal electrocatalyst for organic synthesis and simultaneous H2 production.展开更多
Emerging two-dimensional(2D)materials have stimulated tremendous scientific and industrial interests due to their diverse and tunable physical,chemical,and mechanical properties.The scalable production of high-quality...Emerging two-dimensional(2D)materials have stimulated tremendous scientific and industrial interests due to their diverse and tunable physical,chemical,and mechanical properties.The scalable production of high-quality wafer-scale 2D materials has become significantly essential to bring us closer to practical industrial applications,particularly in electronic devices.Vapor-phase growth provides attractive opportunities for the synthesis of large-area and high-quality 2D materials.In this review,we will emphasize vapor-phase growth strategies from three aspects,including suppressing nucleation,seamless stitching,and evolutionary selection growth.We discuss the general understanding of the related fundamental mechanism and specific parameter optimization from precursors and substrate design to the adjusting of growth parameters(temperature and pressure).Meanwhile,we present other strategies to produce various kinds of wafer-scale 2D materials.Finally,we conclude the current challenges and future directions in this developing field.This work may inspire researchers to better design routes in the synthesis of wafer-scale 2D materials with high quality.展开更多
测定5-氯-2戊酮和环丙基甲基酮的物化性质:密度、黏度、摩尔体积、热膨胀系数和表面张力。测定5-氯-2-戊酮(1)+环丙基甲基酮(2)二元体系的汽液相平衡(VLE),并应用Aspen Plus V11中Van Laar方程、Wilson方程和NRTL方程对实验数据进行关联...测定5-氯-2戊酮和环丙基甲基酮的物化性质:密度、黏度、摩尔体积、热膨胀系数和表面张力。测定5-氯-2-戊酮(1)+环丙基甲基酮(2)二元体系的汽液相平衡(VLE),并应用Aspen Plus V11中Van Laar方程、Wilson方程和NRTL方程对实验数据进行关联,回归得到二元交互参数。实验结果通过热力学一致性检查。该研究不仅补充了汽液相平衡数据库,也为5-氯-2-戊酮与环丙基甲基酮的分离提供热力学数据。展开更多
螺旋管蒸汽发生器是液态金属快堆中能量传递的核心设备,其运行的稳定性、安全性对核电站的运行有至关重要的影响。为此,本文构建了液态金属快堆螺旋管蒸汽发生器一次侧、二次侧耦合传热的三维数值模型,分别基于经济合作与发展组织核能署...螺旋管蒸汽发生器是液态金属快堆中能量传递的核心设备,其运行的稳定性、安全性对核电站的运行有至关重要的影响。为此,本文构建了液态金属快堆螺旋管蒸汽发生器一次侧、二次侧耦合传热的三维数值模型,分别基于经济合作与发展组织核能署(The Organisation for Economic Co-operation and Development,OECD/NEA)物性手册和美国国家标准与技术研究院(National Institute of Standards and Technology,NIST)数据库建立液态金属和水-水蒸气变物性计算关联式,采用Lee相变模型计算二次侧水-水蒸气蒸发过程中两相间的质量传递。基于实验数据,分别对本文模型一次侧传热以及二次侧传热的计算可靠性进行了验证。最后以铅铋快堆为例,研究了不同一次侧进口参数下蒸汽发生器一、二次侧之间的耦合传热特性,并与传统水冷堆进行了对比。结果表明:在同等条件下,相比于传统水冷堆,一次侧采用铅铋液态金属时,一、二次侧之间的壁面热流密度明显提升,热流密度峰值可达1439.97 kW·m^(-2),比水冷堆相应数值提升5~6倍,这导致二次侧管内气相蒸发过程明显加剧,体积含气率急剧上升;同时,一、二次侧之间的沿程热流密度分布更加不均匀,沿程热流密度分布相对偏差值比水冷堆相应数值增大3~4倍。随着一次侧进口铅铋温度从350℃增大到450℃,一、二次侧之间的壁面热流密度随之增大,对应的热流密度峰值从950.7 kW·m^(-2)增大到1439.97 kW·m^(-2),提升约1.5倍,同时一、二次侧之间的沿程热流密度分布更加不均匀,不均匀度增大20%。展开更多
文摘Kinetic regularities of 4-phenyl-o-tolunitrile ammoxidation on V-Sb-Bi-Zr/γ-Al2O3 oxide catalyst in the temperature interval 633 - 673 K have been studied. It has been established that rates of conversion of 4-phenyl-o-tolu- nitrile into the aimed 4-phenylphthalonitrile and CO2 are described by half-order equation on concentration of substratum and to be independent of the oxygen and ammonia partial pressures. It has been revealed that formation of 4-phenylphthalimide from byproducts is due to hydrolysis of 4-phenylphthalonitrile;carbon dioxide is produced by oxidation of 4-phenyl-o-tolunitrile and decarboxylation of 4-phenylphthalimide, and 4-phenylben- zonitrile is produced from 4-phenyl-o-tolunitrile and 4-phenylphthalimide.
基金supported by the Key Laboratory of Fine Chemicals,Jiangsu Provincefinancially supported by the Jiangsu Province Science and Technology Support Program (BE2011651)the Key University Science Research Project of Jiangsu Province (11KJA610002)
文摘MnSAPO-34 molecular sieves were synthesized by vapor-phase transport （VPT） method using triethylamine （Et3N） as a structure directing agent （SDA）, and were characterized by XRD, BET, SEM, UV-Vis, FT-IR, and TG analy- ses. The influence of the zeolite crystallization conditions and the dry-gel composition were investigated. The results showed that the synthesis conditions had an effect on the crystalline phase. Pure MnSAPO-34 had been obtained when it was crystallized at 140 C for 18 hours. The ratio of MnO/A1203 in the starting gel ranging from 0.1 to 0.2 resulted in pure MnSAPO-34 with a CHA topology. Beyond this scope, MnSAPO-5 with an AFI topology structure was obtained as an impurity substance. UV-Vis spectroscopy and FT-IR spectroscopy study indicated that manganese was incorporated into the framework of the molecular sieve. The catalytic performance of MnSAPO-34 molecular sieve was tested by ketalization reaction of l, 2-propanediol with cyclohexanone. High yield of cyclohexanone-1, 2-propanediol ketal was obtained.
文摘Vapor-phase nitration of benzene over solid acid catalyst is expected to be a clean process with no sulfuric acid waste. We investigated this process over solid acidic catalysts utilizing diluted nitric acid (60-70%) as nitrating agent, and found that supported sulfuric acid catalyst exhibited a very high catalytic activity. Under the conditions of reaction temperature 160-170℃, space velocity (SV) 1200 h-1, the yield and the space-time yield (STY) of nitrobenzene (NB) based on HNO3 were more than 98% and 0.75 kg穔gcat-1穐-1 over 10% H2SO4/SiO2 (by weight) catalyst respectively.
基金Project(03SSY4056) supported by the Bureau of Science and Technology of Hunan Province, China Project(04C034) supported by the Bureau of Education of Hunan Province, China
文摘A stable δ- and β-bismuth trioxide was prepared at room temperature by vacuum vapor-phase oxidation. The average crystal size of products was 14.6 nm (by XRD), the d(0.5) value was in the range from 62 nm to 69 nm, and geometric standard deviation(GSD) was from 1.42 to 1.64. The results show that δ-Bi2O3 is formed when quenching rates is rapid and β-Bi2O3 is formed when it is slow. The size of grains increases with rising reaction temperature, flow rate of carrier gas, residual pressure of system and longer growing time of grains.
基金support of the National Natural Science Foundation of China(Nos.22379096,52271222,51971146,51971147,52171218,52371230)support of Shanghai Outstanding Academic Leaders Plan,the Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-07-E00015)+2 种基金Shanghai Pujiang Program(No.21PJ1411100)Shanghai Rising-Star Program(Nos.20QA1407100,21QA1406500)the Shanghai Science and Technology Commission(Nos.21010503100,20ZR1438400,22ZR1443900).
文摘With many merits such as facile synthesis,economy,and relatively high theoretical capacity,Prussian blue analogs(PBAs)are considered promising cathode materials for sodium-ion batteries(SIBs).However,their practical applications still suffer from a low actual specific capacity and inferior stability owing to the imperfect crystallinity,irreversible phase transition,and low intrinsic conductivity.Herein,a surface-modification technique for vapor-phase molecular self-assembly was developed to prepare Fe-based PBAs,specifically sodium iron hexacyanoferrate(NaFeHCF),with a uniform conductive polymer protective layer of polypyrrole(PPy)on the surface,resulting in NaFeHCF@PPy.The incorporation of a PPy protective layer not only improves the electronic conductivity of NaFeHCF@PPy,but also effectively mitigates the dissolution of Fe-ions during cycling.Specifically,this advanced vapor-phase technique avoids Fe^(2+)oxidation and Na^(+)loss during liquid-phase surface modification.The NaFeHCF@PPy exhibited a remarkably enhanced cycling performance,with capacity retentions of 85.6%and 69.1%over 500 and 1000 cycles,respectively,at 200 mA/g,along with a superior rate performance up to 5 A/g(fast kinetics).Additionally,by adopting this strategy for Mn-based PBAs(NaMnHCF@PPy),we further demonstrated the universality of this method for PBA cathodes in SIBs.
基金financially supported by National Natural Science Foundation of China(No.22178143)Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515110365 and2020B1515120036)+3 种基金Natural Science Foundation of Anhui Higher Education Institutions(No.2023AH050168)Innovation and Entrepreneurship Training Program for China College Students(No.202310878049)Director Foundation of Anhui Province Engineering Laboratory of Advanced Building Materials(No.JZCL2305ZR)Ph.D.Startup Foundation of Anhui Jianzhu University(No.2023QDZ34)。
文摘Hypercrosslinked polymers(HCPs)with large surface areas,high intrinsic porosities and low production costs may be available platforms for iodine capture.However,the lack of iodine-philicity binding sites limits their adsorption capacity.Here we use vapor-phase postsynthetic amination strategy to introduce electron-donating amino groups into the prefabricated HCPs for enhancing their iodine capture performance.Through simple vapor-phase exposure,the halogen-containing HCPs can be grafted by amines through nucleophilic substitution toward chloro groups.Combining with the abundant amino groups and high porosities,the amino-functionalized porous polymers show substantially increased iodine adsorption capacity,about 221%as that of original one,accompanied by excellent recyclability.Mechanism investigations reveal the key roles of the electron-donor amino groups andπ-conjugated benzene rings along with structure characteristics of porous polymer frameworks in iodine capture.Moreover,this vapor-phase amination strategy shows good generality and can be extended to various amines,e.g.,ethylenediamine,1,3-diaminopropane and diethylenetriamine.Our work proves that this simple vapor-phase postsynthetic functionalization strategy may be applied in other porous polymers with wide application prospects in adsorption,separation and storage.
基金the National Key Basic Research Development Plan“973”Project(No.2006CB202508)the National Key R&D Program of China(No.2021YFA1502600)+2 种基金State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC)(No.33600000-20-ZC0607-0024)the SINOPEC Project(Nos.411058 and 413025)the National Natural Science Foundation(Nos.21808244,22178347,and 22072182).
文摘Developing efficient and stable zeolites for vapor-phase Beckmann rearrangement of cyclohexanone oxime is still a great challenge to realizeε-caprolactam(CPL)green production.In this work,the hierarchical porous silicalite-1 zeolites with multiple hollow structure(S-1-M)are explored by in-situ desilication−recrystallization post-treatment of spongy highway-like zeolites(S-1-S),which are synthesized through silanization synthesis of conventional bulky silicalite-1(S-1).Compared to S-1,S-1-M achieves superior catalytic performance,with improving the CPL selectivity from 85.7%to 94.1%and prolonging the catalyst lifetime from 74 to 126 h at a weight hourly space velocity(WHSV)of 6 h^(−1).Comprehensive physiochemical studies demonstrate that the highly dispersed intracrystalline cavities within S-1-M endow greater mass diffusion and better quasi acidity inducing by the enhanced H-bonds among abundant H-bonded silanols,which is cooperatively responsible for its superior catalytic performance.
文摘Electrocatalytic synthesis of value-added chemicals is attracting significant research attention owing to its mild reaction conditions, environmental benignity, and potentially scalable application to organic synthetic chemistry. Herein, we report the preparation of a single-crystalline NiS2 nanostructure film of N 50 nm thickness grown directly on a carbon fiber doth （NiSJCFC） by a facile vapor-phase hydrothermal （VPH） method. NiSJCFC as an electrocatalyst exhibits activity for both the oxygen evolution reaction （OER） and the hydrogen evolution reaction （HER） in alkaline media. Furthermore, a series of alcohols （2-propanol, 2-butanol, 2-pentanol, and cyclohexanol） were electrocatalytically converted to the corresponding ketones with high selectivity, efficienc and durability using the NiSJCFC electrode in alkaline media. In the presence of 0.45 M alcohol, a remarkably decreased overpotential （- 150 mV, vs. RHE） at the NiS2/CFC anode compared with that for water oxidation to generate O2, i.e., the OER, in alkaline media leads to significantly improved H2 generation. For instance, the H2 generation rate in the presence of 0.45 M 2-propanol is almost 1.2-times of that obtained for pure water splitting, but in a system that employs an applied voltage at least 280 mV lower than that required for water splitting to achieve the same current density （20 mA-crn-2）. Thus, our results demonstrate the applicability of our bifunctional non-precious-metal electrocatalyst for organic synthesis and simultaneous H2 production.
基金The research was supported by the National Natural Science Foundation of China(grants 21673161)the Science and Technology Department of Hubei Province(grant 2017AAA114)+1 种基金the Postdoctoral Innovation Talent Support Program of China(BX20180224)the Sino-German Center for Research Promotion(grant 1400).
文摘Emerging two-dimensional(2D)materials have stimulated tremendous scientific and industrial interests due to their diverse and tunable physical,chemical,and mechanical properties.The scalable production of high-quality wafer-scale 2D materials has become significantly essential to bring us closer to practical industrial applications,particularly in electronic devices.Vapor-phase growth provides attractive opportunities for the synthesis of large-area and high-quality 2D materials.In this review,we will emphasize vapor-phase growth strategies from three aspects,including suppressing nucleation,seamless stitching,and evolutionary selection growth.We discuss the general understanding of the related fundamental mechanism and specific parameter optimization from precursors and substrate design to the adjusting of growth parameters(temperature and pressure).Meanwhile,we present other strategies to produce various kinds of wafer-scale 2D materials.Finally,we conclude the current challenges and future directions in this developing field.This work may inspire researchers to better design routes in the synthesis of wafer-scale 2D materials with high quality.
文摘测定5-氯-2戊酮和环丙基甲基酮的物化性质:密度、黏度、摩尔体积、热膨胀系数和表面张力。测定5-氯-2-戊酮(1)+环丙基甲基酮(2)二元体系的汽液相平衡(VLE),并应用Aspen Plus V11中Van Laar方程、Wilson方程和NRTL方程对实验数据进行关联,回归得到二元交互参数。实验结果通过热力学一致性检查。该研究不仅补充了汽液相平衡数据库,也为5-氯-2-戊酮与环丙基甲基酮的分离提供热力学数据。
文摘螺旋管蒸汽发生器是液态金属快堆中能量传递的核心设备,其运行的稳定性、安全性对核电站的运行有至关重要的影响。为此,本文构建了液态金属快堆螺旋管蒸汽发生器一次侧、二次侧耦合传热的三维数值模型,分别基于经济合作与发展组织核能署(The Organisation for Economic Co-operation and Development,OECD/NEA)物性手册和美国国家标准与技术研究院(National Institute of Standards and Technology,NIST)数据库建立液态金属和水-水蒸气变物性计算关联式,采用Lee相变模型计算二次侧水-水蒸气蒸发过程中两相间的质量传递。基于实验数据,分别对本文模型一次侧传热以及二次侧传热的计算可靠性进行了验证。最后以铅铋快堆为例,研究了不同一次侧进口参数下蒸汽发生器一、二次侧之间的耦合传热特性,并与传统水冷堆进行了对比。结果表明:在同等条件下,相比于传统水冷堆,一次侧采用铅铋液态金属时,一、二次侧之间的壁面热流密度明显提升,热流密度峰值可达1439.97 kW·m^(-2),比水冷堆相应数值提升5~6倍,这导致二次侧管内气相蒸发过程明显加剧,体积含气率急剧上升;同时,一、二次侧之间的沿程热流密度分布更加不均匀,沿程热流密度分布相对偏差值比水冷堆相应数值增大3~4倍。随着一次侧进口铅铋温度从350℃增大到450℃,一、二次侧之间的壁面热流密度随之增大,对应的热流密度峰值从950.7 kW·m^(-2)增大到1439.97 kW·m^(-2),提升约1.5倍,同时一、二次侧之间的沿程热流密度分布更加不均匀,不均匀度增大20%。
