热壁加氢反应器的检验技术

阐述了热壁加氢反应器的结构特点及一般选材,对制造、使用过程中可能出现的腐蚀、材质裂化、裂纹及其他损伤情况进行了归纳,对损伤产生的原因、防止或减少损伤发生的方法进行了总结。重点论述了热壁加氢反应器的检验技术,根据基层和内衬层的材质、结构特点,对无损检测方法分别进行了总结,最后对风险检验技术在热壁加氢反应器检验的应用进行了介绍。     

热壁加氢反应器堆焊残余应力分析

<正> 一、引言 在石油加工中,加氢精制及加氢裂化是提高油品质量改变油品结构的二次深加工。加氢反应器是加氢装置的核心设备。由于运行在高温、高压、氢介质作用下,通常在反应器筒体(9/2Gr-Mo钢)内壁堆焊奥氏体不锈钢,以防止硫化氢等介质的腐蚀。但是,近年来,又发现热壁加氢反应器,在高     

热壁加氢反应器的无损检测技术

热壁加氢反应器是一种具有复杂结构的设备,对热壁加氢反应器的无损检测方法进行分析和探讨,具有一定的指导意义.     

热壁加氢反应器的现场安装

在现代石油化工行业里,如果企业想要将自身产品质量很好的提升,就必须要使用加氢反应器设备,加氢反应器设备也已经成为了提升企业产品质量最为关键的设备,再加上国家不断提升石油产品的质量标准,我国国内的炼油企业也都陆续建设起加氢精制的项目,但是,在很多企业实施加氢精制项目的过程中,都不能很好的实施加氢反应器的现场安装工作,而加氢反应器的现场安装工作恰巧是整个项目施工过程中十分重要的环节之一,热壁加氢反应器的安装工作主要采取的现场组装技术不仅仅能够将大型设备在运输方面存在的难题很好的解决,还能够将设备制作的工期有效缩短,进而加强企业的项目建设质量。本文中,笔者就对热壁加氢反应器的现场安装进行分析和探讨。     

热壁加氢反应器的现场安装

加氢反应器是现代石油化工行业中,提高产品质量的关键设备。随着国家对石油产品质量标准的不断提高,国内炼油企业于近些年纷纷建设加氢精制项目,而加氢反应器的现场安装是整个项目施工流程中非常重要的一个环节。采用现场组装技术既能够解决大型设备的运输难题、又能够缩短设备制作工期,加快企业项目建设速度。     

加氢类设备内壁单层堆焊试验研究

介绍了通过选用特定的堆焊材料及合理的工艺参数 ,来实现加氢类设备内壁耐腐蚀层单层堆焊的焊接技术     

热壁加氢反应器的选材及材料的回火脆性

文章结合抚顺石油二厂精制加氢反应器的设计,就热壁加氢反应器的选材、材料的回火脆性的表现形式、评价标准及影响因素进行了探讨,并对控制回火脆性敏感性的措施进行了总结。结果认为２２５Ｃｒ－１Ｍｏ钢中硅含量对回火脆性敏感性有很大影响,应注意对硅含量的控制。     

加氢反应器不锈钢堆焊层表面裂纹原因分析及返修工艺探讨

对某乙烯裂解装置二段加氢反应器进行检验,发现上下封头与筒体对接环焊缝及人孔内壁奥氏体不锈钢堆焊层整圈弥散型表面裂纹。基于渗透检测、相控阵检测、铁素体检测、理化检验等结果对裂纹产生原因进行分析,提出了针对性的缺陷返修处理工艺,缺陷返修部位再次检测的结果说明返修工艺是有效地,为同类工艺设备的返修处理提供参考。     

热壁加氢反应器常见缺陷与防治措施

针对2.25Cr-1Mo钢制反应器的特征，对在正常运行过程中和停运时产生的氢腐蚀，回火脆性，应力腐蚀裂纹，氢脆及裂纹，堆焊层剥离等常见缺陷，破坏机理及防治措施进行分析，为反应器安全使用及科学检测提供了理论依据。     

热壁加氢反应器的检验

通过无损检测、化学成分分析、材料性能测试、回火脆化倾向评定和金相检验等,对一台旧热壁加氢反应器的安全性能进行了综合分析。检验结果表明,该台已运行100kh的加氢反应器的安全等级为3级。     

M(BH_4)_n对氢吸附性能的研究

采用DFT中Dmol~3软件包对M(BH_4)_n(M=Ca,Mg,n=1,2,3)进行结构优化,应用Adsorption Locator软件包模拟M(BH_4)_n对氢的吸附,并对产生的能量变化进行计算。结果表明:M(BH_4)_n可以完成优化,最多在300步即可完成;Mg(BH_4)_2与Ca(BH_4)_2对氢的吸附存在差异,主要在吸附点及吸附能。Mg(BH_4)_2在0Ha处形成态密度的峰要比Ca(BH_4)_2尖锐,但是Ca(BH_4)_2形成态密度的峰较宽,说明Ca(BH_4)_2成键较强,电子离域性强。     

Isoform-Specific Effects of Apolipoprotein E on Hydrogen Peroxide-Induced Apoptosis in Human Induced Pluripotent Stem Cell (iPSC)-Derived Cortical Neurons

Hydrogen peroxide (H₂O₂)-induced neuronal apoptosis is critical to the pathology of Alzheimer’s disease (AD) as well as other neurodegenerative diseases. The neuroprotective effects of apolipoprotein (ApoE) isoforms against apoptosis and the underlying mechanism remains controversial. Here, we have generated human cortical neurons from iPSCs and induced apoptosis with H₂O₂. We show that ApoE2 and ApoE3 pretreatments significantly attenuate neuronal apoptosis, whereas ApoE4 has no neuroprotective effect and higher concentrations of ApoE4 even display toxic effect. We further identify that ApoE2 and ApoE3 regulate Akt/FoxO3a/Bim signaling pathway in the presence of H₂O₂. We propose that ApoE alleviates H₂O₂-induced apoptosis in human iPSC-derived neuronal culture in an isoform specific manner. Our results provide an alternative mechanistic explanation on how ApoE isoforms influence the risk of AD onset as well as a promising therapeutic target for diseases involving neuronal apoptosis in the central nervous system.     

ESR Study of Cerium (IV) Oxide in Vacuum Air and Hydrogen

Cerium (IV) oxide prepared at high temperatures in air shows ESR absorption signals. The oxide prepared at low temperatures shows very diffuse signals. Heating the oxide in vacuum at 1000° or in hydrogen at 298° results in a reduction of the intensity of the signal. A theory was developed to show that the ESR signal is obtained from the quasi free electron in non-stoichiometric ceria.     

Hydrogen solubility in coal liquid (SRC-II)

Experimental results are presented for hydrogen solubility in hydrogenated coal liquid (SRC-II) and coal-liquid partial pressure in the hydrogen-coal-liquid system, over temperature and pressure ranges of 420–680 K and 4–11 MPa. Two in situ hydrogen probes were used to determine the hydrogen partial pressure in the system. No coking was observed at these temperature levels. The results are in good agreement with hydrogen solubility data for similar hydrogen-bearing systems reported in the literature. The hydrogen solubility exhibits an inversion with increasing temperature at constant total pressure, which can be interpreted in terms of the strong dependence of the coal-liquid partial pressure on temperature.     

Ca(BH_4)_3NH_4储氢材料的性能研究分析

采用DFT模拟软件对Ca(BH_4)_3NH_4结构进行优化,并对氢气进行吸附模拟。结果表明:Ca(BH_4)_3NH_4可在130步内完成优化,结构优化后产生的能量收敛为2.0000e-005,梯度收敛为4.0000e-003A,移位收敛为5.0000e-003A;Ca(BH_4)_3NH_4可对氢气产生十个吸附点,而仅有一个吸附点最强,产生的吸附能为-0.95kcal/mol;Ca-N键键长随温度出现先降低后增高的情况。     

无损探伤中的着色（一）

阐述了无损探伤中的着色技术,推荐了用于着色渗透探伤、荧光渗透探伤、磁粉探伤着色中使用的染料,汇集了众多专利配方和市场上使用的无损探伤着色渗透液、荧光渗透液、荧光磁粉商品。     

无损探伤中的着色（二）

阐述了无损探伤中的着色技术,推荐了用于着色渗透探伤、荧光渗透探伤、磁粉探伤着色中使用的染料,汇集了众多专利配方和市场上使用的无损探伤着色渗透液、荧光渗透液、荧光磁粉商品。     

钒中氢元素的分析方法研究

研究了用LECO RH600定氢仪,建立了用脉冲加热红外吸收法测定钒中氢的分析方法。通过实验选择了仪器最佳工作条件,方法的准确度可靠,精密度良好,方法快速准确,灵敏度高,结果令人满意。     

Hydrogen adsorption on clean and oxygen covered Pt(111)

The dissociative adsorption of hydrogen on oxygen covered Pt(111) has been investigated using molecular beam techniques. The D₂-sticking probability has been measured as a function of oxygen coverage (0 < _O < 0.25 ML) and angle of incidence for two incident energies, 14 and 63 meV. In addition, the order of the oxygen layer has been measured using thermal He-scattering. The measurements show clear evidence for the existence of two distinct adsorption processes both on the oxygen covered and on the clean Pt(111) surface, i.e. in the limit were _O approaches zero: an activated process which depends on the total oxygen coverage and a non activated process which is sensitive only to the amount of locally ordered oxygen. The non activated process can be explained in terms of a mechanism involving a short living precursor state. The picture for the activated process is less clear. The dependence of this process on the incident energy seems strong evidence for a mechanism involving a barrier to dissociation directly upon impact, whereas the dependence on the oxygen coverage supports previously reported experiments which seem to be only compatible with a precursor mechanism.     

Study of the microstructure formation mechanisms of poly(ether-ether-ketone) monofilaments via melt spinning

The microstructure formation mechanism of melt-spun Poly(ether-ether-ketone) monofilaments during poststretching was investigated using in-situ wide-angle X-ray diffraction in combination with polarizing microscopy, differential scanning calorimetry and universal testing machine. As PEEK monofilaments were stretched at 210°C, the crystallinity and microcrystal size first increased during the insulation state (Is-S), then decreased during the poststretching state (Ps-S), and further increased during the postcooling state (Pc-S), at last were observed to selective orientation. At 210°C, the anisotropically aligned molecular chains reach a meritocratic orientation in the stress direction under 4.0 times drawing conditions, resulting in the highest tensile strength and modulus. As the stretching ratio increases, the crystallinity and microcrystal size first increase during Pc-S and then decrease due to the effect of the stretched molecular chains on crystal growth and the degree of tearing in the crystalline region. The molecular chains of PEEK monofilaments stretched by uniaxial stress are aligned more flatly and uniformly along the fiber axis. We hope that this work will provide advice and guidance for the industrial production of high-performance fibers.