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High temperature and high pressure rheological properties of high-density water-based drilling fluids for deep wells 被引量:12
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作者 Wang Fuhua Tan Xuechao +3 位作者 Wang Ruihe Sun Mingbo Wang Li Liu Jianghua 《Petroleum Science》 SCIE CAS CSCD 2012年第3期354-362,共9页
To maintain tight control over rheological properties of high-density water-based drilling fluids, it is essential to understand the factors influencing the theology of water-based drilling fluids. This paper examines... To maintain tight control over rheological properties of high-density water-based drilling fluids, it is essential to understand the factors influencing the theology of water-based drilling fluids. This paper examines temperature effects on the rheological properties of two types of high-density water-based drilling fluids (fresh water-based and brine-based) under high temperature and high pressure (HTHP) with a Fann 50SL rheometer. On the basis of the water-based drilling fluid systems formulated in laboratory, this paper mainly describes the influences of different types and concentration of clay, the content of a colloid stabilizer named GHJ-1 and fluid density on the rheological parameters such as viscosity and shear stress. In addition, the effects of aging temperature and aging time of the drilling fluid on these parameters were also examined. Clay content and proportions for different densities of brine-based fluids were recommended to effectively regulate the rheological properties. Four theological models, the Bingham, power law, Casson and H-B models, were employed to fit the rheological parameters. It turns out that the H-B model was the best one to describe the rheological properties of the high-density drilling fluid under HTHP conditions and power law model produced the worst fit. In addition, a new mathematical model that describes the apparent viscosity as a function of temperature and pressure was established and has been applied on site. 展开更多
关键词 high-density water-based drilling fluid rheological behavior CLAY high temperature high pressure linear fitting rheological model mathematical model
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Kinetics of Non-catalyzed Decomposition of D-xylose in High Temperature Liquid Water 被引量:23
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作者 荆琪 吕秀阳 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第5期666-669,共4页
The kinetics of non-catalyzed decompositions of xylose and its decomposition product furfural in high temperature liquid water (HTLW) was studied for temperature from 180 to 220℃ and under pressure of 10MPa. The ma... The kinetics of non-catalyzed decompositions of xylose and its decomposition product furfural in high temperature liquid water (HTLW) was studied for temperature from 180 to 220℃ and under pressure of 10MPa. The main products of xylose decomposition were furfural and formic acid, and furfural further degraded to formic acid under HTLW condition. With the assumption of first order kinetics e.quation, the evaluated activation energy of xylose and furfural decomposition was 123.27kJ·mol^-1 and 58.84kJ·mol^-1, respectively. 展开更多
关键词 high temperature liquid water XYLOSE FURFURAL DECOMPOSITION reaction kinetics
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Experimental study on liquid immiscibility of lamprophyre-sulfide melt at high temperature and high pressure and its geological significance
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作者 LI Bo HUANG Zhilong ZHU Chengming 《Chinese Journal Of Geochemistry》 EI CAS 2009年第2期198-203,共6页
With lamprophyre and pyrite from the Laowangzhai gold deposit, Yunnan Province, China, as starting materials, and at pressures from 1.5 to 3.0 GPa and temperatures from 1160 to 1560℃ , an experimental study was carri... With lamprophyre and pyrite from the Laowangzhai gold deposit, Yunnan Province, China, as starting materials, and at pressures from 1.5 to 3.0 GPa and temperatures from 1160 to 1560℃ , an experimental study was carried out on the liquid immiscibility of lamprophyre-sulfide melt at high temperature and ultra-high pressure in the DS-29A cubic 3600T/6-type high pressure apparatus. Results showed that the liquid immiscibility of lampro-pyre-sulfide melt in the magmatic system would happen during the early magmatic evolution (high temperature and high pressure conditions) and was controlled by temperature and pressure. The sulfide melt which was separated from the lamprophyric melt would make directional movement in the temperature and pressure field and assemble in the low-temperature and low-pressure region. Because the density of SM is higher than that of the lamprophyric melt, the former would gather together at the bottom of the magma chamber and there would exist a striking boundary between the two melts. On the other hand, the results also suggested that there would be little possibility for lampro-phyric magma to carry massive gold, and lamprophyres can't provide many of oreforming materials (Au) in the processes of gold mineralization. 展开更多
关键词 液态不混溶 高温高压 硫化物 煌斑岩 地质意义 熔体 液体 试验
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Kinetics of non-catalyzed hydrolysis of tannin in high temperature liquid water 被引量:2
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作者 Li-li LU Xiu-yang LU Nan MA 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2008年第5期401-406,共6页
High temperature liquid water(HTLW) has drawn increasing attention as an environmentally benign medium for organic chemical reactions,especially acid-/base-catalyzed reactions. Non-catalyzed hydrolyses of gallotannin ... High temperature liquid water(HTLW) has drawn increasing attention as an environmentally benign medium for organic chemical reactions,especially acid-/base-catalyzed reactions. Non-catalyzed hydrolyses of gallotannin and tara tannin in HTLW for the simultaneous preparation of gallic acid(GA) and pyrogallol(PY) are under investigation in our laboratory. In this study,the hydrolysis kinetics of gallotannin and tara tannin were determined. The reaction is indicated to be a typical consecutive first-order one in which GA has formed as a main intermediate and PY as the final product. Selective decomposition of tannin in HTLW was proved to be possible by adjusting reaction temperature and time. The present results provide an important basic data and reference for the green preparation of GA and PY. 展开更多
关键词 high temperature liquid water GALLOTANNIN Tara tannin Non-catalyzed hydrolysis KINETICS
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Various admixtures to mitigate the long-term strength retrogression of Portland cement cured under high pressure and high temperature conditions 被引量:2
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作者 Jiankun Qin Xueyu Pang +2 位作者 Ashok Santra Guodong Cheng Hailong Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第1期191-203,共13页
In order to investigate the problem of long-term strength retrogression in oil well cement systems exposed to high pressure and high temperature(HPHT)curing conditions,various influencing factors,including cement sour... In order to investigate the problem of long-term strength retrogression in oil well cement systems exposed to high pressure and high temperature(HPHT)curing conditions,various influencing factors,including cement sources,particle sizes of silica flour,and additions of silica fume,alumina,colloidal iron oxide and nano-graphene,were investigated.To simulate the environment of cementing geothermal wells and deep wells,cement slurries were directly cured at 50 MPa and 200?C.Mineral compositions(as determined by X-ray diffraction Rietveld refinement),water permeability,compressive strength and Young’s modulus were used to evaluate the qualities of the set cement.Short-term curing(2e30 d)test results indicated that the adoption of 6 m m ultrafine crystalline silica played the most important role in stabilizing the mechanical properties of oil well cement systems,while the addition of silica fume had a detrimental effect on strength stability.Long-term curing(2e180 d)test results indicated that nano-graphene could stabilize the Young’s modulus of oil well cement systems.However,none of the ad-mixtures studied here can completely prevent the strength retrogression phenomenon due to their inability to stop the conversion of amorphous to crystalline phases. 展开更多
关键词 high pressure and high temperature(HPHT) Strength retrogression Young’s modulus water permeability Rietveld method
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Enhanced Acid/Base Catalysis in High Temperature Liquid Water 被引量:1
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作者 Xiu Yang LU Qi JING Zhun LI Lei YUAN Fei GAO Xin LIU 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第6期841-844,共4页
Two novel and environmentally benign solvent systems, organic acids-ennchea high temperature liquid water (HTLW) and NH3-enriched HTLW, were developed, which can enhance the reaction rate of acid/base-catalyzed orga... Two novel and environmentally benign solvent systems, organic acids-ennchea high temperature liquid water (HTLW) and NH3-enriched HTLW, were developed, which can enhance the reaction rate of acid/base-catalyzed organic reactions in HTLW. We investigated the decomposition of fructose in organic acids-enriched HTLW, hydrolysis of cinnamaldehyde and aldol condensation of phenylaldehyde with acetaldehyde in NH3-enriched HTLW. The experimental results demonstrated that organic acids-enriched or NH3-enriched HTLW can greatly accelerate acid/base-catalyzed organic reactions in HTLW. 展开更多
关键词 high temperature liquid water acid/base-catalysis organic reactions.
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Hydrolysis kinetics of benzyl phenyl ether in high temperature liquid water
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作者 Xiao Yu Wu Xiu Yang Lu 《Chinese Chemical Letters》 SCIE CAS CSCD 2011年第6期733-737,共5页
The application of high temperature liquid water(HTLW) to decomposition of lignin as efficient and green solution for phenolic compounds recovery was studied.Benzyl phenyl ether(BPE),the lignin model compound,was ... The application of high temperature liquid water(HTLW) to decomposition of lignin as efficient and green solution for phenolic compounds recovery was studied.Benzyl phenyl ether(BPE),the lignin model compound,was treated at temperatures ranging from 220 to 250℃.BPE undergo hydrolysis in HTLW,and main products were phenol and benzyl alcohol with the minimum selectivities of 75.7%and 82.8%,respectively.Lower temperature led to higher selectivity in 220-250℃temperature range.The kinetics on BPE hydrolysis was studied and the activation energy was determined as 150.3±12.5 kJ/mol with the first-order kinetic equations.Based on products distribution,the reaction mechanism for decomposition of benzyl phenyl ether was proposed.The investigated process provides insights into the design of a commercial method for utilization of lignin. 展开更多
关键词 HYDROLYSIS KINETICS Benzyl phenyl ether high temperature liquid water Lignin model compound
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Solid-liquid state pressure bonding of Si_3N_4 ceramics with aluminum based alloys and its mechanism
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作者 邹贵生 吴爱萍 任家烈 《中国有色金属学会会刊:英文版》 CSCD 2001年第2期177-182,共5页
Solid liquid state pressure bonding of Si 3N 4 ceramics with aluminum based alloys, which contain a small amount of intermetallic compounds Al 3Ti or Al 3Zr, was investigated. With this new method, the heat resistant ... Solid liquid state pressure bonding of Si 3N 4 ceramics with aluminum based alloys, which contain a small amount of intermetallic compounds Al 3Ti or Al 3Zr, was investigated. With this new method, the heat resistant properties of the bonding zone metal are improved, and the joints’ strengths at high temperature is increased. The joints’ shear strength at room temperature and at 600 ℃ reach 126~133 MPa and 32~34 MPa, respectively, with suitable bonding pressure. The reaction between aluminum and Si 3N 4 ceramics, which produces Al Si N O type compounds is the dominant interfacial reaction, while the reactions between the second active element Ti or Zr in the aluminum based alloys and Si 3N 4 ceramics also occur to some extend. [ 展开更多
关键词 solid liquid state pressure bonding Si 3N 4 ceramics intermetallic compounds high temperature properties
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Flow Characteristics of Crude Oil with High Water Fraction during Non-heating Gathering and Transportation 被引量:1
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作者 LüYuling Tan Hao +2 位作者 Li Jiao Yang Donghai Xu Peiyang 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2021年第1期88-97,共10页
In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil... In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil with high water fraction was studied in a flow experimental system of the X Oilfield.Four distinct flow patterns were identified by the photographic and local sampling techniques.Especially,three new flow patterns were found to occur below the pour point of crude oil,including EW/O&W stratified flow with gel deposition,EW/O&W intermittent flow with gel deposition,and water single-phase flow with gel deposition.Moreover,two characteristic temperatures,at which the change rate of pressure drop had changed obviously,were found during the change of pressure drop.The characteristic temperature of the first congestion of gel deposition in the pipeline was determined to be the safe temperature for the non-heating gathering and transportation of high water cut crude oil,while the pressure drop reached the peak at this temperature.An empirical formula for the safe temperature was established for oil-water flow with high water fraction/low fluid production rate.The results can serve as a guide for the safe operation of the non-heating gathering and transportation of crude oil in high water fraction oilfields. 展开更多
关键词 crude oil with high water fraction non-heating gathering and transportation flow pattern pressure drop safe temperature
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Adjustment of Liquid Production in Reservoir with Handling Capacity Constraints
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作者 Jie Tan Dong Zhang +2 位作者 Dongdong Yang Songru Mou Qin Peng 《Journal of Geoscience and Environment Protection》 2019年第4期18-25,共8页
A oilfield was an oil reservoir with strong bottom water in offshore, the water cut was as high as 96%. In the high water cut stage, the most effective way of increasing oil production was to extract liquid and increa... A oilfield was an oil reservoir with strong bottom water in offshore, the water cut was as high as 96%. In the high water cut stage, the most effective way of increasing oil production was to extract liquid and increase oil. The processing capacity of oilfield fluid was limited by the conditions. By using Petrel-RE-2017 software, combining reservoir engineering and percolation mechanics methods, this paper analyzes the effect of large-scale liquid pumping, expand coverage and shut-in coning in oil reservoirs with bottom water, and formulates the adjustment strategy of single well production structure of the whole oilfield. It was confirmed that large-scale liquid production can expand coverage and shutting down well can reduce water cut. It can provide reference and guidance for oil field with strong bottom water when it encounters bottleneck of liquid treatment capacity. 展开更多
关键词 Strong BOTTOM water RESERVOIR high water Cut liquid PRODUCTION Structure Adjustment MAXIMUM liquid PRODUCTION Capacity MAXIMUM Reasonable pressure BOTTOM water Coning
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Determination of 16 Species of OCPs in Water by Liquid-liquid Extraction-GC
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作者 Li Ting Zhu Weiping +1 位作者 Xu Xiuyan Yang Hui 《Meteorological and Environmental Research》 CAS 2014年第1期55-58,共4页
[Objective] The research aimed to study the determination of 16 kinds of OCPs in water by liquid-liquid extraction -GC. [Method] The new method for determining 16 kinds of OCPs in water by liquid-liquid extraction -GC... [Objective] The research aimed to study the determination of 16 kinds of OCPs in water by liquid-liquid extraction -GC. [Method] The new method for determining 16 kinds of OCPs in water by liquid-liquid extraction -GC was established, and the influencing factors such as nitrogen pressure and water bath temperature were discussed. [ Result] Detection limit of the method was from 3.2 to 14.1 ng/L, the relative standard deviation was between 4.0% and 9.6%, and the average recovery ranged from 80.8% to 106.0%. By optimizing nitrogen pressure and water bath temperature in the sample pretreatment process, when nitrogen pressure was +0.087 kPa, and water bath temperature was ±36 ℃, recovery effect of this method was better. [ Conclusion] The determination method had accurate qualitative and quantitative results, and met detection requirement of 16 kinds of OCPs in water. 展开更多
关键词 liquid-liquid extraction - GC OCPS Nitrogen pressure water bath temperature China
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自适应变分模态分解算法在高温高压水空化特性分析中的应用
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作者 许博 胡鸿飞 王海军 《西安交通大学学报》 EI CAS 北大核心 2025年第1期56-67,共12页
针对高温高压流动工况下,空化状态判断困难、传统分析方法难以有效提取压力脉动信号中的有效信息的问题,以孔板为对象,开展了高温高压水的空化实验,并提出了一种基于遗传算法的自适应变分模态分解(AVMD)算法。该算法通过结合中心频率法... 针对高温高压流动工况下,空化状态判断困难、传统分析方法难以有效提取压力脉动信号中的有效信息的问题,以孔板为对象,开展了高温高压水的空化实验,并提出了一种基于遗传算法的自适应变分模态分解(AVMD)算法。该算法通过结合中心频率法、遗传算法、功率谱熵和相对能量等技术,自适应地确定变分模态分解算法中的超参数并有效去除信号中的噪声成分,提高了空化特征的提取精度。结果表明:AVMD算法能够精确捕捉到高温高压水流经孔板时空化现象的发生和发展,识别空化起始点、转捩点以及空化强度的变化;当高温高压水流经孔板后,压力脉动的无量纲频率在0.04~0.35、压力脉动的无量纲幅值在0.014~0.067时,空化现象开始出现;随着空化强度增加,管内压力脉动幅值和频率整体呈增大趋势;空化起始转捩点及空化严重转捩点与入口压力和工质入口过冷度密切相关。AVMD算法能够有效提高空化特性分析的精度,尤其是在复杂流动条件下的空化预测,为压水堆核电站冷却剂系统和高压蒸汽系统的稳定运行提供理论依据和参考。 展开更多
关键词 高温高压水 空化特性 自适应变分模态分解 孔板
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盾尾刷更换时液氮冻结温度场及冻结参数影响的数值模拟分析 被引量:1
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作者 杨平 毛一祥 姚梦威 《隧道建设(中英文)》 CSCD 北大核心 2024年第1期69-77,共9页
为合理确定高水压下液氮冻结止水更换盾尾刷的冻结设计参数及掌握温度场变化规律,结合某过江通道长距离盾构掘进过程中盾尾刷更换时的液氮冻结止水工程,利用ADINA大型有限元分析软件建立液氮冻结止水及盾尾刷更换数值模型,模拟温度-时... 为合理确定高水压下液氮冻结止水更换盾尾刷的冻结设计参数及掌握温度场变化规律,结合某过江通道长距离盾构掘进过程中盾尾刷更换时的液氮冻结止水工程,利用ADINA大型有限元分析软件建立液氮冻结止水及盾尾刷更换数值模型,模拟温度-时间变化曲线与现场实测数据对比,验证模型的合理性,并对土层、去路液氮温度、冻结管长度、冻结管间距、冻结方式进行敏感性因素分析。结果表明:1)冻结效果随土层的不同而发生改变,在卵石层、砾砂层、粉细砂层3种土层中,粉细砂层的冻结效果最差,卵石层最好;2)在有限的冻结时间内,去路液氮温度的不同,只影响土体从开始冻结至越过0℃完成相变这期间的降温速度,不影响完成冻结以后的土体降温速率;3)冻结管长度对土层冻结的影响较小,可以采用较短的冻结管,以降低施工成本和液氮消耗量,但不能过短,应保证其纵向有足够的支撑范围,经计算分析,当冻结管长度为1.52 m时,能在轴面处满足2.0 m的冻结壁厚度要求;4)冻结管间距对冻结效果影响大,冻结管越密,冻结速度越快,效果越好;5)在相同条件下,双环预埋冻结管液氮冻结效果优于管片上直接打孔液氮冻结。 展开更多
关键词 高水压砂性地层 盾尾刷更换 液氮冻结法 数值分析 温度场
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阻燃涤纶织物的高温高压法制备 被引量:1
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作者 郑兆临 董君婕 +2 位作者 刘雁雁 李好帅 郑振荣 《印染》 CAS 北大核心 2024年第6期62-65,共4页
通过高温高压法对涤纶织物进行阻燃整理,讨论了碱预处理、渗透剂JFC、三聚氰胺质量分数、浴比、整理时间等对涤纶阻燃性能的影响。结果表明,涤纶织物经过碱预处理后,损毁长度减小到12.5 cm,使用渗透剂JFC可以消除涤纶织物燃烧时带来的... 通过高温高压法对涤纶织物进行阻燃整理,讨论了碱预处理、渗透剂JFC、三聚氰胺质量分数、浴比、整理时间等对涤纶阻燃性能的影响。结果表明,涤纶织物经过碱预处理后,损毁长度减小到12.5 cm,使用渗透剂JFC可以消除涤纶织物燃烧时带来的熔滴。当三聚氰胺质量分数为10%、渗透剂JFC为2 g/L、浴比为1∶30、温度为130℃、时间为60 min时,整理后阻燃涤纶织物的损毁长度由原布的30.0 cm(烧穿)减小到8.4 cm,无续燃、阴燃和熔滴,极限氧指数由原布的21.0%提高为30.8%,且整理对织物的力学性能影响不大。经过5次水洗后,阻燃涤纶织物的损毁长度为13.7 cm、极限氧指数为28.4%,无熔滴,具有较好的阻燃性能。 展开更多
关键词 阻燃整理 高温高压法 涤纶 耐水洗 三聚氰胺
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模拟压水堆一回路环境下冷应变对321不锈钢高温电化学行为和应力腐蚀开裂行为的影响
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作者 李东兴 曹晗 +4 位作者 高俊宣 郑全 张鹏 钟巍华 杨文 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第8期1671-1678,共8页
321不锈钢是常用的压水堆结构材料之一,在成型加工和服役期间易因各种因素发生冷应变,使其性能发生改变。本文在模拟压水堆一回路水化学环境中,测量了不同冷应变量321不锈钢的电化学阻抗谱,并用热应变样品作为对比;采用慢应变速率拉伸... 321不锈钢是常用的压水堆结构材料之一,在成型加工和服役期间易因各种因素发生冷应变,使其性能发生改变。本文在模拟压水堆一回路水化学环境中,测量了不同冷应变量321不锈钢的电化学阻抗谱,并用热应变样品作为对比;采用慢应变速率拉伸测试了冷应变试样应力腐蚀开裂性能。使用X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)对样品微观特征进行了分析。XRD分析表明,冷应变使基体发生了由奥氏体到马氏体的转变,而高温抑制了这一过程。随着应变程度的增大(至20%),电荷转移电阻增大,膜电阻随马氏体含量的升高而降低。裂纹萌生实验结果表明,马氏体优先发生氧化腐蚀,保护了奥氏体基体,抑制了应力腐蚀裂纹萌生。 展开更多
关键词 压水堆 321不锈钢 冷应变 高温电化学 应力腐蚀开裂
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密闭空间内高压过冷水射流冲击高温铅铋熔池能质传输数值模拟研究
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作者 袁俊杰 刘莉 +5 位作者 包睿祺 罗皓天 贾政 田晓艳 李达 顾汉洋 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第9期1958-1969,共12页
蒸汽发生器传热管破裂(SGTR)事故是铅铋冷却快堆(LFR)最为严重的设计基准事故之一,将导致二回路高压过冷水通过管道破口高速射流注入一回路高温液态铅铋(LBE),强烈的相间热质传输可能引发蒸汽爆炸,严重威胁堆芯结构的完整性。为了揭示S... 蒸汽发生器传热管破裂(SGTR)事故是铅铋冷却快堆(LFR)最为严重的设计基准事故之一,将导致二回路高压过冷水通过管道破口高速射流注入一回路高温液态铅铋(LBE),强烈的相间热质传输可能引发蒸汽爆炸,严重威胁堆芯结构的完整性。为了揭示SGTR事故现象机理,本文基于VOF多相流模型、LES湍流模型和Lee相变模型,考虑容器内覆盖气体层作用,建立了密闭空间内高压过冷水射流冲击高温LBE多相流动与瞬态传热传质过程的三维数值计算模型,重点分析了过冷水温度及入口压力对射流发展和射流周围环境(即覆盖气体层和LBE区域)的影响。结果表明,典型的射流按相态可分为4个区域,即水-蒸汽过渡区、多相流区、末端水相区和蒸汽斑块区。射流沸腾主要发生在射流中心区域和两侧的相界面上,相变产生的蒸汽夹带残余水相沿着界面从射流的末端向顶部迁移,计算工况下最大沸腾速率通常在喷管出口处,为7090 kg/(m^(3)·s)。覆盖气体层和LBE区压力与过冷水温度和入口压力均呈正相关,LBE区压力会随着射流发展逐渐增加,同时蒸汽的迁移可能引起LBE区压力发生波动,在4.4 ms时间内在覆盖气体层和LBE区获得的最大压力分别为0.157 MPa和0.351 MPa。本文结果揭示了射流沸腾机理与压力演化特性,为铅铋冷却快堆SGTR事故系统安全评估提供了理论支撑。 展开更多
关键词 密闭空间 高压过冷水射流 高温LBE 能质传输 数值模拟
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液态CO_(2)-水蒸气循环冲击煤体增透及瓦斯抽采效果模拟
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作者 秦雷 王平 +4 位作者 李树刚 王辉 刘鹏飞 李嘉伟 林海飞 《煤田地质与勘探》 EI CAS CSCD 北大核心 2024年第9期67-79,共13页
【目的】为解决液态CO_(2)煤层增透技术应用时煤层内部孔隙水受冷凝结为冰阻塞瓦斯运移通道这一问题,提出液态CO_(2)-高温水蒸气冷热循环冲击煤体增透技术。【方法】利用低场核磁共振仪、煤岩渗透率自动测试仪、接触角测试仪和三维CT扫... 【目的】为解决液态CO_(2)煤层增透技术应用时煤层内部孔隙水受冷凝结为冰阻塞瓦斯运移通道这一问题,提出液态CO_(2)-高温水蒸气冷热循环冲击煤体增透技术。【方法】利用低场核磁共振仪、煤岩渗透率自动测试仪、接触角测试仪和三维CT扫描仪分析液态CO_(2)-高温水蒸气冷热循环冲击煤体渗透率演化规律。【结果和结论】结果表明:(1)液态CO_(2)-高温水蒸气冷热循环冲击煤体T2曲线面积随冷热循环冲击次数增加而增加。(2)煤体渗透率增量与液态CO_(2)-高温水蒸气冷热循环冲击次数指数相关,循环冲击次数增加,煤体渗透性和润湿性均增强。(3)液态CO_(2)-高温水蒸气冷热循环冲击次数达到12次时,渗流孔体积比例增加23.57%,渗透率增加0.009 3×10^(-3)μm^(2),接触角减小39.45°。(4)煤体渗透性与渗流孔体积比例、接触角相关,渗流孔体积比例与煤体渗透率正相关,接触角与煤体渗透率指数相关。基于实验研究结果,利用COMSOL软件数值模拟低温液态CO_(2)-高温水蒸气冷热循环冲击煤层工程现场应用。依据试验结果确定恢复到室温25℃时的有效作用半径为0.719 8 m,以此数据模拟矿井煤层瓦斯抽采,结果显示煤层温度与瓦斯抽采效率成正比。试验及模拟结果揭示了液态CO_(2)-高温水蒸气冷热循环冲击煤体增透技术的现场钻孔布置及瓦斯抽采运移规律,为该技术下一步现场应用提供参考。 展开更多
关键词 液态CO_(2) 高温水蒸气 冷热冲击 渗透率 瓦斯抽采
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低压静电场协同低温高湿解冻对牛肉嫩度和持水性的影响
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作者 李晴晴 白小佳 +3 位作者 林珩迅 张春晖 夏双梅 李侠 《食品工业科技》 CAS 北大核心 2024年第20期49-58,共10页
为探究低压静电场协同低温高湿解冻对牛肉嫩度和持水性的影响,本研究以牛背最长肌为试验材料,分析了低压静电场解冻(电压2500 V,温度4℃,相对湿度50%)、低温高湿解冻(温度4℃,相对湿度98%)、低压静电场协同低温高湿解冻(电压2500 V,温度... 为探究低压静电场协同低温高湿解冻对牛肉嫩度和持水性的影响,本研究以牛背最长肌为试验材料,分析了低压静电场解冻(电压2500 V,温度4℃,相对湿度50%)、低温高湿解冻(温度4℃,相对湿度98%)、低压静电场协同低温高湿解冻(电压2500 V,温度4℃,相对湿度98%)与低温解冻(温度4℃,相对湿度50%)四种解冻方式对冷冻牛肉剪切力、质构、水分分布、水分含量、持水性、感官评价的影响。结果表明:低压静电场协同低温高湿解冻的解冻时间最短(804 min),其中解冻损失(2.06%)、蒸煮损失(26.09%)与离心损失(15.00%)显著低于其余三种解冻方式(P<0.05),垂直肌纤维剪切力值(95.46 N)和平行肌纤维剪切力值(41.69 N)最低,自由水含量最低,水分迁移较少,水分含量(68.31%)最高,嫩度品质最优,该解冻方式样品的组织状态、气味、弹性及色泽均最优(总体可接受度最高);综上,低压静电场协同低温高湿解冻加快了牛肉解冻速率、减少了汁液流失,改善了牛肉持水性和嫩度,品质最佳。本研究结果将为低压静电场协同低温高湿解冻技术在冷冻牛肉解冻的产业应用提供理论依据。 展开更多
关键词 冷冻牛肉 低压静电场 低温高湿解冻 协同作用 持水性 嫩度
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(Yb_(0.25)Lu_(0.25)Tm_(0.25)Y_(0.25))_(2)Si_(2)O_(7)环境障涂层材料的制备及其性能
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作者 何翰伟 郭星晔 +2 位作者 周正 吴旭 吴杨 《中国表面工程》 EI CAS CSCD 北大核心 2024年第5期296-304,共9页
环境障涂层(EBCs)可以有效保护SiC陶瓷基复合材料(CMC-SiC)免受航空发动机高温水氧环境中的腐蚀。稀土焦硅酸盐(RE_(2)Si_(2)O_(7))因其与SiC基体匹配的热膨胀系数和良好的高温性能,成为理想的EBC候选材料之一,然而其耐高温水蒸气腐蚀... 环境障涂层(EBCs)可以有效保护SiC陶瓷基复合材料(CMC-SiC)免受航空发动机高温水氧环境中的腐蚀。稀土焦硅酸盐(RE_(2)Si_(2)O_(7))因其与SiC基体匹配的热膨胀系数和良好的高温性能,成为理想的EBC候选材料之一,然而其耐高温水蒸气腐蚀性能尚无法满足其服役需求,有待进一步优化。取四种稀土元素设计并制备一种新型高熵焦硅酸盐硅陶瓷(Yb_(0.25)Lu_(0.25)Tm_(0.25)Y_(0.25))_(2)Si_(2)O_(7)((4RE_(0.25))_(2)Si_(2)O_(7))。稀土元素Yb和Lu对应的焦硅酸具有单一的β相结构及优秀的抗高温水氧腐蚀性能,稀土元素Tm和Y的焦硅酸也具有β相结构及较低的热导率。试验结果表明,采用无压烧结成功制备出具有单斜β相的(4RE_(0.25))_(2)Si_(2)O_(7)块材,差示扫描量热法(DSC)曲线无明显的吸/放热峰,从室温到1300℃保持平直,具有良好的相稳定性。(4RE_(0.25))_(2)Si_(2)O_(7)具有较低的热膨胀系数(CTE,2.66×10^(−6)~3.84×10^(−6)℃^(−1))和热扩散系数(0.41~0.92 mm^(2)/s)。在1300℃,90%Air-10%H_(2)O的气氛中腐蚀200 h,质量损失仅0.625 mg/cm^(2),远低于Yb2Si2O7的失重,(4RE_(0.25))_(2)Si_(2)O_(7)表现出了较好的抗高温水蒸气腐蚀能力。设计并制备的新型(Yb_(0.25)Lu_(0.25)Tm_(0.25)Y_(0.25))_(2)Si_(2)O_(7)高熵硅酸盐陶瓷在热学性能和抗高温水氧腐蚀性能方面具有一定优势,有望成为一种潜在的高性能环境障涂层材料。 展开更多
关键词 环境障涂层 高熵焦硅酸盐 无压烧结 热学性能 高温水蒸气腐蚀
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储氢技术研究现状及进展 被引量:4
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作者 张林海 丁学强 +3 位作者 张新 孙世铮 张思懿 刘德军 《中外能源》 CAS 2024年第4期17-27,共11页
储氢环节是连接氢生产到应用的桥梁,也是高效利用氢能的基础。高压气态储氢技术最成熟、应用最广泛,研制轻质、高压、耐腐蚀性强、稳定性好的储氢容器将是未来高压储氢的研发热点。固态储氢是利用固体材料吸附方式实现氢的存储,主要包... 储氢环节是连接氢生产到应用的桥梁,也是高效利用氢能的基础。高压气态储氢技术最成熟、应用最广泛,研制轻质、高压、耐腐蚀性强、稳定性好的储氢容器将是未来高压储氢的研发热点。固态储氢是利用固体材料吸附方式实现氢的存储,主要包括金属材料、复合氢化物、碳基材料、有机框架储氢材料、无机多孔储氢材料等。从储能密度角度看,低温液态储氢是一种十分理想的储氢方式,但也存在能量损失大、成本高昂等问题。有机液态储氢具有储氢密度大、安全性好、载体可循环使用等显著优点,被认为是最有希望实现大批量、远距离氢储运的重要方式之一,甲基环己烷(MCH)、二苄基甲苯(DBT)、N-乙基咔唑(NEC)、甲醇/甲酸等是当前有机物储氢介质的研究热点且具有商业化前景。目前有机液态储氢还存在脱氢效率低、能耗大、氢纯度不足等问题,大部分技术仍处于研究或初期示范阶段。短期内高压气态储氢仍是储氢方式的主流选择。中期内发展的重点是有机液态储氢和固态储氢,低温液态储氢主要应用在大批量、长距离的特殊储运场景。长期来看,融合多种储氢方式的优点,开发集成式耦合储氢技术是未来发展的关键,高效、长寿命、经济性好的储氢介质/催化剂体系是未来储氢技术的研究重点。 展开更多
关键词 高压气态储氢 固态储氢 低温液态储氢 有机液态储氢 储氢密度 储氢介质
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