期刊文献+
共找到34,867篇文章
< 1 2 250 >
每页显示 20 50 100
Improved hydrogen storage properties of LiBH4 confined with activated charcoal by ball milling
1
作者 He Zhou Xin-Hua Wang +2 位作者 Hai-Zhen Liu Shi-Chao Gao Mi Yan 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第4期321-326,共6页
In order to enhance the hydrogen storage properties of LiBH4,activated charcoal (AC) was used as the scaffold to confine LiBH4 in this paper.Ball milling was used to prepare LiBH4/AC composites.Experimental results sh... In order to enhance the hydrogen storage properties of LiBH4,activated charcoal (AC) was used as the scaffold to confine LiBH4 in this paper.Ball milling was used to prepare LiBH4/AC composites.Experimental results show that dehydrogenation properties of ball-milled LiBH4/AC (LiBH4/AC-BM) are greatly improved compared with that of pristine LiBH4,ball-milled LiBH4 (LiBH4-BM) and hand-milled LiBH4/AC (LiBH4/AC-HM).The onset dehydrogenation temperature of LiBH4 for LiBH4/AC-BM is around 160 ℃,which is 170 ℃ lower than that of pristine LiBH4.At around 400 ℃,LiBH4/AC-BM finishes the dehydrogenation with a hydrogen capacity of 13.6 wt%,which is approximately the theoretical dehydrogenation capacity of pure LiBH4 (13.8 wt%),while the dehydrogenation processes for LiBH4-BM and LiBH4/AC-BM do not finish even when they were heated to 600 ℃.The isothermal dehydriding measurements show that it takes only 15 min for LiBH4/AC-BM to reach a dehydrogenation capacity of 10.1 wt% at 350 ℃,whereas the pristine LiBH4 and the LiBH4/AC-HM release hydrogen less than 1 wt% under the same conditions.The dehydrogenation process and the effect of AC were discussed. 展开更多
关键词 HYDROGEN STORAGE properties HYDROGEN STORAGE materials Lithium BOROHYDRIDE ACTIVATED charcoal
NiPt nanoparticles supported on CeO2 nanospheres for efficient catalytic hydrogen generation from alkaline solution of hydrazine
2
作者 Yana Men Jun Su +3 位作者 Xiangli Wang Ping Cai Gongzhen Cheng Wei Luo 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第3期634-637,共4页
Searching for highly efficient catalysts toward dehydrogenation of hydrazine for chemical hydrogen storage is highly desirable for the development of hydrogen economy. Herein, we report a simple in situ co-reduction s... Searching for highly efficient catalysts toward dehydrogenation of hydrazine for chemical hydrogen storage is highly desirable for the development of hydrogen economy. Herein, we report a simple in situ co-reduction synthesis of NiPt nanoparticles supported on CeO2 nanospheres and their superior catalytic performance for hydrogen generation from alkaline solution of hydrazine at room temperature. Thanks to the strong electronic interaction arising from synergistic effect at atomic lever and support-metal interaction between NiPt and CeO2.The obtained Ni5Pt5-CeO2 catalyst exhibits 100% hydrogen selectivity and superior catalytic performance for hydrogen generation from alkaline solution of hydrazine at room temperature, with a TOF value of 416 h 1. 展开更多
关键词 HYDROGEN storage HYDRAZINE HYDROGEN evolution CEO2 NANOSPHERES Support-metal in teraction
光催化分解水制备氢气和过氧化氢 预览
3
作者 王利超 曹爽 +3 位作者 郭凯 吴志娇 马智 朴玲钰 《催化学报》 SCIE EI CAS CSCD 北大核心 2019年第3期470-475,共6页
过氧化氢不仅是一种广泛应用于化学合成、消毒、废水处理及纸浆漂白等领域的高价值化学品,还是一种具有潜力的能源载体.此外,过氧化氢燃料电池因其结构简单而受到广泛关注.蒽醌法是工业生产过氧化氢的传统方法,但是这种方法不仅能耗高,... 过氧化氢不仅是一种广泛应用于化学合成、消毒、废水处理及纸浆漂白等领域的高价值化学品,还是一种具有潜力的能源载体.此外,过氧化氢燃料电池因其结构简单而受到广泛关注.蒽醌法是工业生产过氧化氢的传统方法,但是这种方法不仅能耗高,而且生产过程会造成严重的环境问题.因此,通过环保并且低成本的工艺直接合成过氧化氢具有重要研究意义.以太阳能为动力的光催化法生产过氧化氢被认为是最有前景的方法之一.目前,光催化已在制氢、二氧化碳还原和水处理等诸多领域取得了重要进展.但是,利用光催化分解水制备过氧化氢的研究还非常少.尽管通过光催化还原氧气可以制备过氧化氢,但是通过分解水同时制备高价值过氧化氢和氢气更具有吸引力.在本项工作中,我们利用Pt/TiO2(锐钛矿)光催化剂在没有牺牲剂的条件下实现了高效产氢和过氧化氢,氢气和过氧化氢的生成速率分别达到7410和5096μmolg–1h–1(第一小时),远高于市售的Pt/TiO2(锐钛矿)体系和文献报道数值.本文采用X射线光电子能谱(XPS)、电子自旋共振(ESR)和荧光标记法等表征手段研究了Pt/TiO2上同时生成氢气和过氧化氢的催化机理.XPS测试结果表明,Pt/TiO2在光照射1h后,XPS信号发生明显变化.与其他样品相比,物理吸附水和羟基的峰明显增加.因此,我们推测羟基和物理吸附水对过氧化氢的生成具有重要影响.进一步采用电子自旋共振(ESR)和荧光标记法对羟基进行了测量.ESR结果显示,紫外光照60s即可检测到羟基捕获剂与羟基的结合物5,5-dimethyl-1-pyrroline-N-oxide-OH(DMPO-OH)的特征峰.此外,在体系中加入荧光标记分子对苯二甲酸(TANa)后也可以迅速检测到2-羟基对苯二甲酸(TAOH)在422nm处明显的荧光信号.因此,ESR和荧光结果均表明所产生的羟基自由基在过氧化氢形成中起着重要作用.上述结果表明,在本体系� 展开更多
关键词 光催化分解水 氢气 过氧化氢 锐钛矿
在线阅读 下载PDF
氢气型溴化锂制冷机组运行总结 预览
4
作者 费信怀 彭靖 《氯碱工业》 CAS 2019年第6期33-35,40共4页
介绍了以氢气为热能制取7℃冷冻水的溴化锂机组的工艺流程及运行情况,分析了机组在运行过程中存在的问题,并提出了解决及改造措施。
关键词 溴化锂 制冷机组 氢气 高压发生器 水封罐 真空度 氢气压力
在线阅读 下载PDF
Characteristics of MOF, MWCNT and graphene containing materials for hydrogen storage: A review 预览
5
作者 Kranthi Kumar Gangu Suresh Maddila +1 位作者 Saratchandra Babu Mukkamala Sreekantha B Jonnalagadda 《能源化学:英文版》 SCIE EI CAS CSCD 2019年第3期132-144,共13页
Hydrogen is a generally abundant, safe, clean and environmentally apt alternative fuel, which replen-ishes the void generated by depleting fossil fuel reserves. The adoption of hydrogen as an energy source has been re... Hydrogen is a generally abundant, safe, clean and environmentally apt alternative fuel, which replen-ishes the void generated by depleting fossil fuel reserves. The adoption of hydrogen as an energy source has been restricted to low levels due to the complications associated with its viable storage and us-age. Existing technologies, such as storage of hydrogen in compressed and liquefied forms are not ade-quate to meet the broad on-board applications. The gravimetric energy density (120 MJ/kg) of hydrogen is three times higher than that of gasoline products, so solid-state hydrogen storage is advantageous. Metal-organic frameworks (MOFs), multi-walled carbon nanotubes (MWCNTs) and graphene are solid ad-sorbents majorly employed for efficient H2 storage. The prominent features of MOFs such as permanent porosity, structural rigidity, and surface area are attractive and ideal for hydrogen storage. In addition, nanostructured carbon materials (MWCNTs and graphene) and their composites have demonstrated sig-nificant hydrogen storage capacities. Some important parameters for the success of the hydrogen econ-omy include high storage density, adsorption/desorption temperature and cycling time. Cryo-hydrogen storage was achieved in MOFs and their composites with carbon structures, but storage at ambient tem-perature and acceptable pressures is a major hurdle. This review discusses various strategies and mecha-nisms in the design of adsorbents explored to improve H2 storage capacities and afford opportunities to develop new sustainable hydrogen technologies to meet energy targets. 展开更多
关键词 HYDROGEN storage METAL-ORGANIC frameworks MWCNTs/Graphene Nanocomposites SPILLOVER HYDROGEN economy
在线阅读 下载PDF
电解水制氢MoS2催化剂研究与氢能技术展望 预览
6
作者 王培灿 雷青 +1 位作者 刘帅 王保国 《化工进展》 EI CAS CSCD 北大核心 2019年第1期278-290,共13页
氢气具有质量轻、热值高、燃烧产物清洁等优点,被认为是理想的能源载体。氢气既能作为燃料电池的燃料,又能作为储能介质调节风能、太阳能发电系统的随机性、间歇性,正在成为未来能源的重要组成部分。为了促进电解水制氢技术与装备发展,... 氢气具有质量轻、热值高、燃烧产物清洁等优点,被认为是理想的能源载体。氢气既能作为燃料电池的燃料,又能作为储能介质调节风能、太阳能发电系统的随机性、间歇性,正在成为未来能源的重要组成部分。为了促进电解水制氢技术与装备发展,研究高效电催化剂十分重要。本文围绕“粉末型”与“自支撑型”电催化剂结构特征,讨论基于二硫化钼(MoS2)的析氢电催化剂的研究现状,阐述了催化活性位点调控策略与提高导电性两条技术途径,并以析氢过电位和塔菲尔曲线斜率为依据,比较不同方法制备的二硫化钼电催化剂的催化活性。表明提高二硫化钼晶相稳定性、调节其电子结构和优化催化电极结构等方法,将进一步提高基于二硫化钼的析氢催化电极性能。 展开更多
关键词 电催化剂 二硫化钼 电解水 制氢
在线阅读 免费下载
TiAlN/TiMoN Coatings as Hydrogen Barriers 预览
7
作者 Motonori Tamura Hidekazu Takizawa 《材料科学与工程:中英文A版》 2019年第1期1-7,共7页
We evaluated the hydrogen barrier properties of a multi-layered coating of TiAlN/TiMoN.Coatings facilitated reductions of the hydrogen permeabilities to 1/1,000 of that of the uncoated substrate.The experiment confirm... We evaluated the hydrogen barrier properties of a multi-layered coating of TiAlN/TiMoN.Coatings facilitated reductions of the hydrogen permeabilities to 1/1,000 of that of the uncoated substrate.The experiment confirmed that the coatings composed of fine crystal grains were highly effective as hydrogen barriers,and that this barrier property became even more efficient if multiple layers of the coatings were applied.The crystal grain boundaries of the coating and interfaces of each film in a multi-layered coating can serve as hydrogen trapping sites.We speculate that fine crystal structures with multiple crystal grain boundaries and multi-layered coating interfaces will contribute to the development of hydrogen barriers. 展开更多
关键词 HYDROGEN PERMEATION multi-layered-coating microstructure HYDROGEN TRAPS
在线阅读 下载PDF
减缓柴油加氢装置硫化氢汽提塔顶空冷腐蚀的工艺研究 预览
8
作者 陈金仙 周尚 《化工设计通讯》 CAS 2019年第5期99-100,共2页
柴油加氢装置通过加氢反应将柴油馏分中的噻吩等硫化物转化为硫化氢,通过闪蒸和蒸汽汽提的方式脱除柴油馏分中溶解的硫化氢。硫化氢汽提塔顶空冷普遍出现管束腐蚀穿孔的现象。荆门石化加氢改质装置由热高分调整为温高分流程,汽提塔空冷... 柴油加氢装置通过加氢反应将柴油馏分中的噻吩等硫化物转化为硫化氢,通过闪蒸和蒸汽汽提的方式脱除柴油馏分中溶解的硫化氢。硫化氢汽提塔顶空冷普遍出现管束腐蚀穿孔的现象。荆门石化加氢改质装置由热高分调整为温高分流程,汽提塔空冷腐蚀严重,经常腐蚀穿孔,存在较大安全隐患。因此,拟通过对工艺条件进行调整,以降低硫化氢汽提塔顶空冷器腐蚀,延长设备使用寿命。 展开更多
关键词 柴油加氢 硫化氢 腐蚀 氢气汽提
在线阅读 下载PDF
阻塞比对氢-空预混火焰加速影响的可视化研究 预览
9
作者 刘福水 李率毅 +2 位作者 张小玉 黎一锴 吴晗 《内燃机工程》 EI CAS CSCD 北大核心 2019年第3期1-9,共9页
在顶置点火定容燃烧弹内布置网孔板,通过火焰传播路径上的孔板诱导实现火焰加速。利用纹影法和压力采集系统,研究了阻塞比对氢-空预混气孔板诱导火焰加速的影响规律。试验结果表明:阻塞比的增加可增大孔板对火焰的扰动,使火焰传播速度... 在顶置点火定容燃烧弹内布置网孔板,通过火焰传播路径上的孔板诱导实现火焰加速。利用纹影法和压力采集系统,研究了阻塞比对氢-空预混气孔板诱导火焰加速的影响规律。试验结果表明:阻塞比的增加可增大孔板对火焰的扰动,使火焰传播速度大幅增加;任意初始工况下均存在一个最佳阻塞比使燃烧持续期达到最短,在试验范围内,较低初始压力、较小当量比和较高初始温度的最佳阻塞比为0. 90,其余工况的最佳阻塞比均在0. 84;孔板诱导燃烧加速的效果非常显著,在试验工况范围内,各阻塞比孔板诱导下的燃烧持续期均缩短45%以上。 展开更多
关键词 阻塞比 定容燃烧弹 诱导湍流 燃烧特性 氢气
在线阅读 下载PDF
基于能源战略规划的日本能源转型研究
10
作者 张慧智 张健 《现代日本经济》 CSSCI 北大核心 2019年第3期14-23,共10页
2018年7月,日本发布第五次《能源战略规划》,首次明确提出了'2050年实现能源转型和脱碳化'的战略目标,结合以往4次《能源战略规划》,会发现能源转型一直是日本能源战略和政策的方向。2011年以前,日本将核能作为推进能源转型的... 2018年7月,日本发布第五次《能源战略规划》,首次明确提出了'2050年实现能源转型和脱碳化'的战略目标,结合以往4次《能源战略规划》,会发现能源转型一直是日本能源战略和政策的方向。2011年以前,日本将核能作为推进能源转型的主力能源,2011年核事故之后,日本在《能源战略规划》中强调,要通过多渠道推进能源转型。日本推动能源转型的主要渠道包括提升化石能源使用效率,增加水能、核能、风能、太阳能等新能源的开发和利用,促进能源节约,加强分布式能源系统建设和氢社会建设等,日本在这些渠道上采取了诸多措施,取得了大量成果。但是,日本当前面临的技术水平限制、民众对核能不信任、相关利益主体掣肘等挑战使得日本能源转型之路充满了不确定性。 展开更多
关键词 日本能源战略 能源转型 能源政策 能源技术 氢能源
Two-dimensional Sn2Ta2O7 nanosheets as efficient visible lightdriven photocatalysts for hydrogen evolution
11
作者 Xiao-Shuai Wang Chao Zhou +2 位作者 Run Shi Qin-Qin Liu Tie-Rui Zhang 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第5期397-403,共7页
Two-dimensional Sn2Ta2O7 nanosheets with a thickness of~10 nm were successfully prepared through a novel tantalic acid-based solid-state reaction method at reduced temperature.The as-obtained samples were characterize... Two-dimensional Sn2Ta2O7 nanosheets with a thickness of~10 nm were successfully prepared through a novel tantalic acid-based solid-state reaction method at reduced temperature.The as-obtained samples were characterized by powder X-ray diffraction(XRD),ultraviolet–visible(UV–Vis)diffuse reflectance spectra,scanning electron microscopy(SEM),transmission electron microscopy(TEM)and Brunauer–Emmett–Teller(BET)analysis.The photocatalytic performance of Sn2 Ta2 O7 nanosheets was evaluated by photocatalytic water splitting for hydrogen evolution under visible light irradiation(k C 400 nm).The Sn2Ta2O7 nanosheets with a large surface area of 25.9 m^2·g^-1 showed higher H2 production activity,which was about 4.4 times higher than that of bulk Sn2 Ta2O7 in lactic acid aqueous solutions using Pt as a cocatalyst.The improved photocatalytic performance mainly benefited from the nanosheet structure,which provided abundant surface active sites and facilitated the photogenerated charge carrier separation efficiently.This workmay open up new opportunity to develop novel nanostructured tantalum-based semiconductors with improved catalytic performance for solar energy conversion. 展开更多
关键词 Sn2Ta2O7 NANOSHEETS VISIBLE light PHOTOCATALYSIS HYDROGEN evolution
An electrodeposition approach to metal/metal oxide heterostructures for active hydrogen evolution catalysts in near-neutral electrolytes
12
作者 Michael J.Kenney Jianan Erick Huang +9 位作者 Yong Zhu Yongtao Meng Mingquan Xu Guanzhou Zhu Wei-Hsuan Hung Yun Kuang Mengchang Lin Xiaoming Sun Wu Zhou Hongjie Dai 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第6期1431-1435,共5页
Neutral water splitting is attractive for its use of non-corrosive and environmentally friendly electrolytes.However,catalyst development for hydrogen and oxygen evolution remains a challenge under neutral conditions.... Neutral water splitting is attractive for its use of non-corrosive and environmentally friendly electrolytes.However,catalyst development for hydrogen and oxygen evolution remains a challenge under neutral conditions.Here we report a simple electrodeposition and reductive annealing procedure to produce a highly active Ni-Co-Cr metal/metal oxide heterostructured catalyst directly on Ni foam.The resulting electrocatalyst for hydrogen evolution reaction (HER) requires only 198 mV of overpotential to reach 100 mNcm2 in 1 M potassium phosphate (pH =7.4) and can operate for at least two days without significant performance decay.Scanning transmission electron microscopy coupled with electron energy loss spectroscopy (STEM-EELS) imaging reveals a Ni-Co alloy core decorated with blended oxides layers of NiO,CoO and Cr2O3.The metal/metal oxide interfaces are suggested to be responsible for the high HER activity. 展开更多
关键词 water SPLITTING CATALYSIS NANOSTRUCTURED materials hydrogen EVOLUTION chemical mapping
Synthesis of TiO2@ZnIn2S4 hollow nanospheres with enhanced photocatalytic hydrogen evolution
13
作者 He Li Zi-Hao Chen +1 位作者 Lei Zhao Gui-Dong Yang 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第5期420-427,共8页
In this work,we designed and prepared the novel TiO2@ZnIn2 S4 nano-sized hollow structure via templating method assisted by hydrothermal synthesis process.Its unique hollow structure and type-II heterojunction between... In this work,we designed and prepared the novel TiO2@ZnIn2 S4 nano-sized hollow structure via templating method assisted by hydrothermal synthesis process.Its unique hollow structure and type-II heterojunction between TiO2 hollow nanospheres and ZnIn2 S4 nanosheet can provide enough interior cavities and transfer paths for the light absorption and charge quick migration.The crystal structure,morphology and charges separation property were measured.The characterization results show that the hollow-structured Ti O2@ZnIn2 S4 was successfully prepared,and the optimal sample exhibited excellent photocatalytic hydrogen generation compared with TiO2/ZnIn2 S4 cluster exceeding by a factor of 1.1 under overall light irradiation.Specially,the detailed mechanism of the photocatalytic H2 evolution and charge carrier migration for the as-prepared TiO2@ZnIn2 S4 hollow nanosphere was also studied. 展开更多
关键词 TIO2 ZnIn2S4 PHOTOCATALYSIS HYDROGEN EVOLUTION HOLLOW
Simulation of hydrogen distribution and effect of Engineering Safety Features (ESFs) on its mitigation in a WWER-1000 containment 预览
14
作者 Omid Noori-kalkhoran Najmeh Jafari-ouregani +1 位作者 Massimiliano Gei Rohollah Ahangari 《核技术:英文版》 SCIE CAS CSCD 2019年第6期88-103,共16页
In this study, thermal–hydraulic parameters inside the containment of aWWER-1000/v446 nuclear power plant are simulated in a double-ended cold leg accident for short and long times (by using CONTAIN 2.0 and MELCOR 1.... In this study, thermal–hydraulic parameters inside the containment of aWWER-1000/v446 nuclear power plant are simulated in a double-ended cold leg accident for short and long times (by using CONTAIN 2.0 and MELCOR 1.8.6 codes), and the effect of the spray system as an engineering safety feature on parameters mitigation is analyzed with the former code. Along with the development of the accident from design basis accident to beyond design basis accident, the Zircaloy–steam reaction becomes the source of in-vessel hydrogen generation. Hydrogen distribution inside the containment is simulated for a long time (using CONTAIN and MELCOR), and the effect of recombiners on its mitigation is analyzed (using MELCOR). Thermal–hydraulic parameters and hydrogen distribution profiles are presented as the outcome of the investigation. By activating the spray system, the peak points of pressure and temperature occur in the short time and remain belowthe maximumdesign values along the accident time. It is also shown that recombiners have a reliable effect on reducing the hydrogen concentration below flame propagation limit in the accident localization area. The parameters predicted by CONTAIN and MELCOR are in good agreement with the final safety analysis report. The noted discrepancies are discussed and explained. 展开更多
关键词 CONTAINMENT HYDROGEN DISTRIBUTION Invessel SEVERE accident Recombiners CONTAIN MELCOR
在线阅读 下载PDF
我国氢能发展现状与前景展望 预览
15
作者 刘坚 钟财富 《中国能源》 2019年第2期32-36,共5页
氢既是重要的工业原料也是支撑未来能源系统清洁转型的重要二次能源。虽然相比电能氢能具有能源互联、易于储存、应用面广等优点,但在我国氢能的发展中也存在技术成熟度不高、产业基础薄弱、安全性有待提高等方面的现实问题。本文从我... 氢既是重要的工业原料也是支撑未来能源系统清洁转型的重要二次能源。虽然相比电能氢能具有能源互联、易于储存、应用面广等优点,但在我国氢能的发展中也存在技术成熟度不高、产业基础薄弱、安全性有待提高等方面的现实问题。本文从我国氢能生产与消费现状出发,分析了未来氢能在我国能源工业中的应用潜力,并重点对氢能生命周期环境影响和技术经济性水平进行了量化分析。研究发现,一次能源的结构显著影响氢能的环境价值。随着燃料电池成本下降,未来氢能利用的竞争力将逐步提升。特别是在重型交通领域推广氢能不仅具有较高的技术可行性和经济性,其在可再生能源为主的电力系统中也具有较高的系统应用价值。 展开更多
关键词 氢能 燃料电池 重型交通 全生命周期分析
在线阅读 下载PDF
Co9S8 nanowires@NiCo LDH nanosheets arrays on nickel foams towards efficient overall water splitting
16
作者 Jingan Yan Ligang Chen Xin Liang 《科学通报:英文版》 SCIE EI CSCD 2019年第3期158-165,共8页
Water electrolysis is considered to be an effective way to fabricate hydrogen, and it is desirable to find the highly efficient, inexpensive and good durability bifunctional electrocatalysts for overall water splittin... Water electrolysis is considered to be an effective way to fabricate hydrogen, and it is desirable to find the highly efficient, inexpensive and good durability bifunctional electrocatalysts for overall water splitting.In this paper, we synthesis a unique structured catalyst that was composed by Co9S8 nanowires and nickel cobalt layered double hydroxide(NiCo-LDH) nanosheets. The ultrathin nanosheets decorated on the Co9S8 nanoarrays offer large specific surface area, numerous active edge sites and excellent electrical conductivity for fast electron transfer. Benefiting from this heterogeneous structure, the catalyst presents excellent catalytic performance in alkaline media. It requires 168 mV to reach current density of 10 mA/cm2 for HER and 278 m V to reach current density of 30 mA/cm2 for OER. When used as electrode in a homemade two-electrode system, it only needs t a voltage of 1.63 V to achieve current densities of 10 mA/cm2, which proves Co9S8@NiCo LDH/NF as a superior bifunctional catalyst for water splitting. 展开更多
关键词 Co9S8 NANOWIRE NiCo LDH Hydrogen EVOLUTION REACTION Oxygen EVOLUTION REACTION Water splitting
MELCOR2.2氢气点燃浓度限值敏感性分析
17
作者 石兴伟 史强 +4 位作者 马国强 宋维 贾斌 左嘉旭 刘福东 《核技术》 CAS CSCD 北大核心 2019年第5期70-74,共5页
严重事故工况下,堆芯燃料包壳和其他金属构件的蒸汽氧化以及熔融堆芯-混凝土相互作用是最重要的氢气释放源项。为避免安全壳内氢气爆燃和爆炸现象,有必要对氢气点火浓度的敏感性进行研究。研究使用最新版MELCOR2.2程序对大功率非能动压... 严重事故工况下,堆芯燃料包壳和其他金属构件的蒸汽氧化以及熔融堆芯-混凝土相互作用是最重要的氢气释放源项。为避免安全壳内氢气爆燃和爆炸现象,有必要对氢气点火浓度的敏感性进行研究。研究使用最新版MELCOR2.2程序对大功率非能动压水堆安全壳进行系统建模,对安全壳内氢气点燃浓度限值进行了敏感性分析。分析结果表明:1)氢气可燃浓度限值设置越高,单次燃烧产生的压力峰值越明显,超过设定的可燃浓度限值,可能引起氢气爆燃和爆炸;2)氢气点燃一定程度上受其他不凝气体浓度影响,其中一氧化碳会加速氢气点燃,而二氧化碳和蒸汽的摩尔浓度增加则会稀释可燃气体。因此,氢气点燃受氢气点燃浓度限值影响较大,但安全壳内其他不凝气体组分的影响也不可忽略,应该及时做好安全壳内可燃气体的复合和稀释,有效消除可燃气体的潜在威胁。 展开更多
关键词 MELCOR2.2 氢气 点燃浓度限值 严重事故 敏感性分析
Underground coal gasification and its strategic significance to the development of natural gas industry in China 预览
18
作者 ZOU Caineng CHEN Yanpeng +3 位作者 KONG Lingfeng SUN Fenjin CHEN Shanshan DONG Zhen 《石油勘探与开发:英文版》 2019年第2期205-215,共11页
Based on the present situation and trend of underground coal gasification in China and overseas, this article puts forward the basic concept, mechanism and mode of underground coal gasification, and presents the chall... Based on the present situation and trend of underground coal gasification in China and overseas, this article puts forward the basic concept, mechanism and mode of underground coal gasification, and presents the challenges, development potential and development path now faced. In China, underground coal gasification which is in accord with the clean utilization of coal can produce "artificial gas", which provides a new strategic approach to supply methane and hydrogen with Chinese characteristics before new energy sources offer large-scale supply. Coal measure strata in oil-bearing basins are developed in China, with 3.77 trillion tons coal reserves for the buried depth of 1000-3 000 m. It is initially expected that the amount of natural gas resources from underground coal gasification to be 272-332 trillion cubic meters, which are about triple the sum of conventional natural gas, or equivalent to the total unconventional natural gas resources. According to the differences of coal reaction mechanism and product composition of underground coal gasification, the underground coal gasification can be divided into three development modes, hydrogen-rich in shallow, methane-rich in medium and deep,supercritical hydrogen-rich in deep. Beyond the scope of underground mining of coal enterprises, petroleum and petrochemical enterprises can take their own integration advantages of technologies, pipeline, market and so on, to develop underground coal gasification business based on their different needs and technical maturity, to effectively exploit a large amount of coal resources cleanly and to alleviate the tight supply of natural gas. It can also be combined with using the produced hydrogen in nearby area and the CO2 flooding and storage in adjacent oil areas to create a demonstration zone for net zero emissions of petroleum and petrochemical recycling economy. It is significant for reserving resources and technologies for the coming "hydrogen economy" era, and opening up a new path for China’s "clean, low carbon, safe a 展开更多
关键词 COAL underground COAL GASIFICATION natural GAS GAS revolution coal-made methane coal-made hydrogen SUPERCRITICAL WATER SUPERCRITICAL WATER GASIFICATION
在线阅读 免费下载
浓度和点火位置对氢气-空气预混气爆燃特性影响 预览
19
作者 郑立刚 朱小超 +5 位作者 于水军 王亚磊 李刚 杜德朋 窦增果 苏洋 《化工学报》 EI CAS CSCD 北大核心 2019年第1期408-416,共9页
开展了氢气-空气预混气在透明方管内的爆燃实验研究,分析在一端开口一端封闭的狭长空间内,浓度和点火位置对氢气-空气预混气爆燃特性的影响。实验结果表明:氢气浓度和点火位置对火焰锋面结构以及发展有重要影响;各当量比条件下,均在距... 开展了氢气-空气预混气在透明方管内的爆燃实验研究,分析在一端开口一端封闭的狭长空间内,浓度和点火位置对氢气-空气预混气爆燃特性的影响。实验结果表明:氢气浓度和点火位置对火焰锋面结构以及发展有重要影响;各当量比条件下,均在距封闭端100mm位置点火时反应最为迅速;在极贫燃或极富燃条件下,点火位置对火焰发展影响更大。氢气浓度与点火位置共同作用于压力波形,以距封闭端300mm点火位置为界,分别在管道前后两段点火时,不同当量比条件下超压波形呈现复杂变化。超压峰值对氢气浓度具有极强依赖性,并且浓度对爆燃超压的影响程度远大于点火位置;在各点火位置下,均在Φ=1.25时获得最大超压;最大超压对应的点火位置取决于当量比。 展开更多
关键词 氢气 浓度 点火位置 爆燃 压力
在线阅读 下载PDF
55SiCr弹簧钢盘条异常断裂原因分析
20
作者 陈杰 李文军 +2 位作者 刘新宽 王军艺 盛荣生 《金属热处理》 CAS CSCD 北大核心 2019年第3期225-230,共6页
从生产现场中发现部分55SiCr弹簧钢盘条在仓库存储的过程中发生异常断裂。对断裂试样进行了断口宏微观形貌、化学成分、显微组织、力学性能、硬度与氢含量的分析以及电化学充氢验证试验,以找出断裂原因。结果表明:55SiCr弹簧钢盘条断裂... 从生产现场中发现部分55SiCr弹簧钢盘条在仓库存储的过程中发生异常断裂。对断裂试样进行了断口宏微观形貌、化学成分、显微组织、力学性能、硬度与氢含量的分析以及电化学充氢验证试验,以找出断裂原因。结果表明:55SiCr弹簧钢盘条断裂试样的化学成分符合行业标准,其抗拉强度为2030 MPa,断面收缩率为38%,硬度平均值为615. 3 HV0. 3,符合技术要求。其异常断裂为应力状态下的氢致开裂,断裂起源点在试样表面的划伤缺陷处,该处在弹簧钢盘卷状态下具有较高的应力集中,容易诱导氢在此处聚集;断裂起源处呈沿晶断裂形貌,自起源点向内不断延伸,继而出现准解理与韧窝特征,裂纹扩展路径与试样所受应力方向垂直。现场发生断裂的试样中含有较少的氢含量,这是由于氢在室温下的逸出所致。 展开更多
关键词 55SiCr弹簧钢 异常断裂 表面缺陷 应力
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈