Mechanical property and permeability of raw coal containing methane under unloading confining pressure

Based on domestic-developed triaxial servo-controlled seepage equipment for thermal-hydrologicalmechanical coupling of coal containing methane,an experimental study was carried out to investigate mechanical property and gas permeability of raw coal,under the situation of conventional triaxial compression and unloading confining pressure tests in different gas pressure conditions.Triaxial unloading confining pressure process was reducing confining pressure while increasing axial pressure.The research results show that,compared with the peak intensity of conventional triaxial loading,the ultimate strength of coal samples of triaxial unloading confining pressure was lower,deformation under loading was far less than unloading,dilation caused by unloading was more obvious than loading.The change trend of volumetric strain would embody change of gas permeability of coal,the permeability first reduced along with volumetric strain increase,and then raised with volume strain decrease,furthermore,the change trends of permeability of coal before and after destruction were different in the stage of decreasing volume strain due to the effect of gas pressure.When gas pressure was greater,the effective confining pressure was smaller,and the radial deformation produced by unloading was greater.When the unloading failed confining pressure difference was smaller,coal would be easier to get unstable failure.

Strengthening pelletization of manganese ore fines containing high combined water by high pressure roll grinding and optimized temperature elevation system

Pelletization is one of useful processes for the agglomeration of iron ore or concentrates. However, manganese ore fines are mainly agglomerated by sintering due to its high combined water which adversely affects the roasting performance of pellets. In this work, high pressure roll grinding(HPRG) process and optimization of temperature elevation system were investigated to improve the strength of fired manganese ore pellets. It is shown that the manganese ore possesses good ballability after being pretreated by HPRG twice, and good green balls were produced under the conditions of blending 2.0% bentonite in the feed, balling for 7 min at 16.00% moisture. High quality roasted pellets with the compressive strength of 2711 N per pellet were manufactured through preheating at 1050 °C for 10 min and firing at 1335 °C for 15 min by controlling the cracks formation. The fired manganese pellets keep the strength by the solid interconnection of recrystallized pyrolusite grains and the binding of manganite liquid phase which filled the pores and clearance among minerals. The product pellets contain high Mn grade and low impurities, and can be used to smelt ferromanganese, which provides a possible way to use imported manganese ore fines containing high combined water to produce high value ferromanganese.

EFFECT OF RESTRAINT STRENGTHENING OF VACUUM-PRESSURED BRAZED JOINT

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Structural Features and In-service Inspection of the LTNHR-200 Pressure Vessel

The pressure vessel of 200 MW low temperature nuclear heating reactor (LTNHR 200) is the main part of primary pressure boundary and its reasonable and reliable structural design is the key point to assure the safe operation of LTNHR 200. The double shell pressure vessels were designed. LTNHR 200 pressure vessel meets the condition of Leak Before Break and has a relatively low failure probability. Metal containment (outer pressure vessel) has the similar features to LTNHR 200 pressure vessel. There exists no LOCA and core melting with the double vessel. The in service inspection of the pressure vessel can be simplified greatly because of the safety and structural features of the reactor.

Dynamic pressure change in a rotating, laterally oscillating cylindrical container

We examined wave phenomena pertinent to water in a rotating,laterally oscillating cylindrical container.In particular,we measured the time-dependent dynamic water pressure and pressure change by fast Fourier transform analysis.The swirling of water in the container had three frequency components;the frequency responses of each frequency component are reported herein.When swirling occurs in a rotating cylindrical container,it was found that the wave rotating in the same direction as the rotation of the cylindrical container and the wave rotating in the opposite direction to the cylindrical container exist at the same time.The swirling direction was determined by the relationship of these magnitude.

Flaw Detection Capability and Sensitivity in the Inspection of Nuclear Containment Liner and Shell Mock-Ups Utilizing a Magnetostrictive Sensor (MsS) Guided Wave UT Technique

This paper describes the results of a project on the inspection of visually inaccessible areas of nuclear containment liners and shells via the advanced Magnetostrictive sensor (MsS) Guided Wave (GW) nondestructive inspection technique. Full scale mockups that simulated shell and liner regions of interest in the containment of both a Pressurized Water Reactor (PWR) and Boiling Water Reactor (BWR) were constructed. Inspections were performed on the mock-ups in three stages to discern the signal attenuation caused by flaws and caused by concrete in the structures. The effect of concrete being in close proximity to the liner and shell was determined, and the capability to detect and size flaws via this GW technique was evaluated.

承压设备绿色低碳发展趋势与展望

承压设备广泛应用在石油化工、电力能源等关系国计民生的重要行业领域,具有量大面广、能源资源消耗量大等特点,在保障能源绿色低碳转型、促进新能源发展中发挥着重要作用。本文重点论述了锅炉、压力容器、油气长输管道等承压设备绿色低碳发展现状和趋势,阐述了承压设备对我国能源绿色低碳转型的安全保障作用,分析了我国承压设备绿色低碳发展法规标准体系脉络。建议进一步发挥好科技创新引领作用,增强承压设备领域科技创新能力,助力我国“双碳”目标实现。

电极尺寸对射流等离子体放电的影响及其在涤纶亲水研究中的应用

大气压脉冲介质阻挡放电射流等离子体中,羟基活性粒子的生成和调控对于等离子体在材料表面改性方面的应用具有重要意义,而羟基活性粒子的形成和调控又与放电结构密切相关。研究了接地电极宽度对大气压脉冲放电射流等离子体的影响:通过改变接地电极宽度,探究其对射流长度、放电强度的影响;通过增强型电荷耦合器件(ICCD)对放电时空演化进行分析;通过发射光谱分析放电产生的特征谱线。结果表明:当接地电极的宽度为1.5 cm时,射流长度最长;在射流3 mm处,有较强的羟基活性粒子浓度。利用大气压脉冲射流等离子体处理涤纶织物表面,验证了气相等离子体中羟基含氧基团与涤纶表面亲水处理效果的正相关性,为等离子体中活性粒子的控制和开发工业用等离子体源提供了参考。

含糖透析液对合并糖尿病的维持性血液透析患者血糖、血压和心率变异性的影响

目前研究提示含糖透析液可有效稳定血糖水平,显著减少透析低血糖事件发生,同时有助于稳定血压和改善心率变异性,对心脑血管风险较高的糖尿病患者尤为重要。这些发现揭示了含糖透析液在提升糖尿病患者透析治疗质量中的潜在价值。然而,针对其长期应用的安全性和有效性,仍需进一步的研究探讨。本文就含糖透析液对合并糖尿病的维持性血液透析患者在透析期间对血糖、血压及心率变异性的影响进行综述,旨在探究含糖透析液在糖尿病维持血液透析治疗中的临床应用价值,为临床决策提供科学依据及研究方向。

高温高压合成含硼金刚石的研究进展

在掺杂金刚石中,含硼金刚石凭借其诸多优良的物化性能成为了近年来的研究热点之一。文章简单介绍了含硼金刚石的结构特征和性能,并以触媒掺硼和石墨掺硼两个分类,对高温高压合成含硼金刚石近年来的研究进行了概括综述。并对采用石墨层间化合物配合触媒合成含硼金刚石进行了总结分析,探讨目前含硼金刚石在导电性能方面所面临的难题,并对其发展进行了展望。

高温高压非金属元素掺杂金刚石的研究进展

金刚石因其优越的极限特性,使得其应用领域非常广泛。金刚石的功能特性往往由其内部所含杂质元素决定,包括非金属元素如硼(B)、氮(N)、硫(S)和磷(P)等。掺杂这些单元素以合成金刚石一直是国内外研究课题的热点。本文首先介绍了金刚石单晶在高温高压条件下的合成方法及其研究发展现状,随后分析了硼(B)、氮(N)、硫(S)、磷(P)等单元素掺杂对金刚石晶体生长和电学等性能的影响。同时对金刚石在半导体中的应用以及金刚石中的含氮色心进行了分析。最后展望了掺杂后金刚石的光学和电学性能研究前景,并指出进一步探索多元素共掺杂的理论和实验方法对提升掺杂金刚石的性能具有重要意义。

静脉血样真空采集容器抽吸体积检测仪的设计

为解决静脉血样真空采集容器抽吸体积检测时人工操作流程复杂、工作效率低的问题,该研究基于YY/T 0314-2021《一次性使用人体静脉血样采集容器》附录B中真空采集容器的抽吸体积检测方法,设计了一种抽吸体积检测仪。该仪器通过分析容器内的压强,利用比例-微分-积分(PID)闭环控制系统调整容器内的压强至目标值,最后通过穿刺实验测得真空采集容器的抽吸体积。验证实验采用人工操作和抽吸体积检测仪两种方法检测5 ml规格真空采集容器的抽吸体积,结果表明,两种方法的误差<1%,且抽吸体积检测仪的检测时间较人工操作缩短约50%。

基于不同功率的非能动安全壳热量导出系统实验研究

“华龙一号”非能动安全壳热量导出系统(passive containment heat removal system,PCS)和“玲龙一号”非能动安全壳热量导出系统设计原理相同,但系统功能和设计准则不尽相同。为了掌握影响系统换热能力和运行的关键因素,本文结合不同项目的特点,从综合性能实验需求和实验结果等方面,研究、分析“华龙一号”非能动安全壳热量导出系统与“玲龙一号”非能动安全壳热量导出系统设计中的典型现象,发现降低冷却水箱水位可以提升系统的换热能力、改变冷管段阻力对系统的换热能力更敏感和冷管段隔离阀关闭方案在开启时可能会有一定的风险,从而提出后续优化研究和设计中需要重点关注的影响因素。文中结论可用于指导相关系统设计工作。

基于“容器人”视角的当代中国低结婚率成因初探

文章根据麦克卢汉的媒介理论,结合心理学相关知识,探讨分析数据升降间的关系,即“容器人”媒介的使用与“婚恋”之间的关系。研究挖掘出新媒体环境下“容器男女”渴望自由、渴望被爱、渴望独特却又不敢暴露、拒他人于千里的矛盾心理,进一步分析“容器男女”婚恋逃离心理成因,即习得性无助及负性行为的模仿。以上现象的产生由多种因素造成,既有技术发展问题,亦有原生家庭及社会原因。建议从青年男女的教育环境、家庭环境、社会环境及心理引导等方面着手,多方治理,打好“组合拳”,破解其当下困境。

加压氧化处理黄金冶炼氰化废水

采用加压氧化方法对黄金冶炼氰化废水进行脱氰处理,研究了反应温度、氧分压、处理时间及酸度等对加压氧化降解氰化废水中总氰、硫氰根及重金属离子脱除规律的影响。结果表明,提高反应温度、氧分压、反应时间和酸度均有利于含氰废水中总氰的脱除,当反应温度80℃、氧分压0.3 MPa、反应时间1 h、酸化时浓硫酸用量0.31 mol/L时,总氰降至22.2 mg/L,静置两天后进一步降至7.73 mg/L,SCN-降至13.8 g/L,Cu降至30.3 mg/L,Fe降至3.21 mg/L,Zn降至2.2 mg/L。铜、铁、锌几乎全部分别以Zn3(Fe(CN)6)2、Cu2Fe(CN)6·2H2O和Fe4(Fe(CN)6)3的形式固定在沉淀物中,进而降低黄金冶炼废水的毒性。降解处理后的废水经调节pH后返回金矿氰化浸出工序,实现废水循环再利用。

柔性管路对密闭容器爆炸压力的影响

为有效控制与管路连接的密闭容器的爆炸风险,降低制造、维护投入成本,通过数值计算分析与实际爆炸试验验证,研究了柔性管路对其连接的密闭容器爆炸压力的影响。以隔爆型外壳为研究对象,选取数值计算数学模型、确定边界条件,比较了阀门关闭及打开,以及连接不同直径柔性管路时,外壳内部爆炸压力的差异,分析爆炸时管路接口处气体流动及压力分布情况;在爆炸槽中对柔性管路连接隔爆外壳进行试验,对比分析试验与数值计算结果。研究结果表明,柔性管路具有泄爆效果,且管路直径越大,内部爆炸压力越小。

基于空运条件的集装箱式生物隔离方舱负压环境设计与实现

目的:研究并设计一种可应用于集装箱式生物隔离方舱的负压环境,以满足在陆、海、空多式联运转运过程中及空运条件下箱内的负压环境稳定及压差动态智能调控。方法:综合分析国内外传染病负压隔离装备的压差设计规范及研究成果,设计一种动力分布式无风道通风系统,通过预设压力冗余、传感器实时监测以及压力动态跟随,实现在空运过程中集装箱内的负压稳定和智能调控。结果:设计的集装箱式生物隔离方舱负压环境经测试,箱内清洁区、缓冲区、污染区、医务人员通道和患者通道的“三区两通道”各区压差满足预设要求,清洁区室外、清洁区卫生间、缓冲区二更的清洁区卫生间、缓冲区一更的污染区、污染区卫生间和污染区室外的压差分别为34.2、38.8、-8.0、-31.7、-15.1和-44.6 Pa。通过箱内布设的传感器及智能显控设备,测试验证箱内各区压差动态能够满足生物安全三级实验室(BSL-3)要求。结论:箱内各区稳定的负压环境和智能压差调控,使集装箱具有更高的生物安全特性,有效保障烈性传染病患者全域安全转运及空运条件下的转运救治。

基于步进算法的安全壳恒压测流系统设计

安全壳作为核电厂的第3道安全屏障,其良好的密封性是在严重事故工况下实现放射性包容的物质基础。为了规避传统压力衰减法安全壳泄漏率测量方案对压力变化具有显著的非线性特征进行回归分析时存在较大测量偏差的问题,本团队研发了恒压法泄漏率测量方案。该方案需要保持安全壳内压力基本恒定,即安全壳气体流入与流出达到动态平衡状态,壳内压力始终围绕目标压力值附件以微小幅度波动。为了实现上述安全壳恒压充气的控制目标,该文基于PLC及步进算法设计研发了恒压测流系统,并通过实验验证其功能,确定其适用于不同规格安全壳的正压、负压等应用场景,能够较好的满足恒压法泄漏率测量方案的功能要求。

Transient pressure analysis for the reactor core and containment of a HTGR after a primary loop pressure boundary break accident

The pressure variances in the reactor core and containment of a High Temperature Gas-cooled Reactor (HTGR) after a primary loop pressure boundary break accident determine the structural integrity and safety of the reactor. Based on mass conservation, energy conservation and state equations, explicit formulae for the transient pressure and temperature variances in the pressure vessels were deduced, and a set of differential equations for the transient pressure and temperature variances in the containment were developed. Numerical simulation was also conducted to investigate the transient pressure and temperature variances in the pressure vessels and containment. The results show that energy transformation due to expansion work cannot be neglected. The maximum pressure in the containment could increase by 40 percent due to blockage caused by air in the containment. Detailed numerical simulations of the transient pressure and temperature variance in the reactor core flow passages were also conducted. The results show that the pressures acting on the reactor core and containment are below acceptable values.

不同含水率及围压条件下含瓦斯煤能量变化规律

为探究含瓦斯煤变形破坏过程中的能量耗散规律,利用自主研制的煤岩力学性质测试装置,开展含瓦斯煤在不同含水率及围压下的常规三轴试验,基于热力学第一定律,分析含瓦斯煤偏应力-应变曲线不同阶段和特征点处的能量变化规律。结果表明:不同含水率时,围压从12 MPa增大到20 MPa时,对应的弹性能占比增幅分别为60.33%、20.11%和3.86%,弹性能占比、破坏强度和弹性模量均增大,说明围压对含瓦斯煤体的变形破坏具有一定的抑制作用;不同围压时,含水率从1%增加到5%,对应的总能量分别下降25.38%、8.78%和6.23%,总能量、弹性能和破坏强度总体上均减小,导致含瓦斯煤更易破坏。含水率的增大使含瓦斯煤颗粒间摩擦力降低,促进煤颗粒间的相对移动。