某连续催化重整装置加热炉炉管开裂原因分析

某连续催化重整装置中反应器上游加热炉的炉管,在服役11a后产生裂纹引发开裂和泄漏.通过对该炉管的化学成分、室温拉伸性能、高温拉伸性能、金相组织、硬度、断口形貌和腐蚀产物的分析查找开裂原因.结果 表明:该炉管的失效为尘化腐蚀所致,炉管内壁渗碳,外壁发生氧化,高温力学性能降低较为明显.     

Cracking of 5Cr steel tee-pipe during start-up operation in heavy oil upgrade refinery

During the start-up operation of an HOU refinery plant, leaking through a crack at the top of a T-pipe was found in a hydrocracking process. Various kinds of metallurgical inspections of the failed T-pipe were performed in order to find the cause of cracking e.g., metallography, fractography, hardness measurement, EDS analysis and hydrogen concentration measurement. Since thermal loading in the T-pipe was usually higher during the start-up operation than under steady operations, a system load analyses of the pipe was conducted. Detailed finite element analysis of the T-pipe was also conducted to identify high stress locations and to assess the stress intensity factor of the crack partly penetrated the T-pipe.The 5Cr T-pipe steel satisfied the chemical composition requirements for ASTM A234 but the tensile strength and hardness were significantly higher than recommended in the standard, which made the pipe steel vulnerable to a hydrogen environment formed by the feed inside of the pipe. The cracking started from the inclusions near the inner surface of the pipe and grew due to the hydrogen effect. Inspection results supporting this argument are explained. And recommendations for preventing similar cracking failures were made.     

Investigation on the deposition failure of a reactor effluent air cooler in hydrocracking unit

The deposition failure of a reactor effluent air cooler (REAC) is investigated by the technical analysis and multiphase flow simulation. The blockages of REAC tubes are mainly induced by the corrosion products come from the upstream heat exchangers, a result of the high temperature H₂S-H₂ corrosion. Meanwhile, NH₄Cl salts crystallize upstream the air coolers and enter into the REAC tubes, flowing along with the corrosion products. Through analyzing the residence times and deposition rates of salts, it is found that the corrosion products tend to deposit on two sides of the header box, the third row of tubes and the regions of low velocities. The temperatures inside the REAC tubes significantly decrease once the tubes are blocked. Fouling of NH₄HS salts occurs when the temperature falls below 30 °C. The expansion and contraction of carbon steel with large difference in temperature lead to the bucking of tubes. The regions with high risk deposition are obtained from simulation, which agree well with the actual failure phenomenon.     

风机盘管机组噪声分析

描述我国风机盘管机组噪声问题的现状,分析导致风机盘管机组噪声的3个主要因素,并着重阐述低频噪声的判断方法以及施工规范对预防风机盘管机组噪声的重要性。     

高翅管蒸汽加热器的设计及改进

介绍高翅管蒸汽加热器的结构形式、工艺流程和主要参数,详细分析其强度计算、材料选择等方面的设计特点,以及为保证运行安全而在结构和工艺方面所采取的设计改进。     

芯管式稠油掺稀混合器设计及其掺混性能研究

掺稀降黏是稠油开采工艺中的重要技术,而混合器是增强掺混效果的主要工具。首先,提出了一种新型芯管式稠油掺稀混合器结构,采用芯管微孔外射的方式,实现稀、稠油在环空内掺混,同时根据"文丘里效应"原理设计变截面锥管结构,以形成不规则湍流,实现二次掺混。该混合器具有掺混效果好、对油液压降影响小等优点。其次,利用CFD（computational fluid dynamics,计算流体动力学）仿真技术研究了微孔直径、微孔密度、喷射角度、内锥角和出入口压差等5个因素对掺混不均匀度系数和掺稀比的影响。最后,针对塔河油田采油二厂的稠油掺稀开采工况,设计了一款可对接3 1/2"油管的混合器,并进行了室内掺混实验分析,获得的掺混不均匀度系数为0.023 4,掺稀比为0.290 1,达到了理想水平,这表明该混合器具有良好的掺稀降黏性能。研究成果为提高稠油开采效率和减小抽油设备的故障率提供了新的技术手段。     

直热式热泵热水机组的开发初探

简要介绍直热式热泵热水机组的开发背景、应用前景、使用优点等,根据实际开发经验,对开发过程中的水温控制问题、除霜问题、高温制热问题等重点难点进行方向性分析,为直热式空气源热泵热水机的开发提供一些思路。     

管坯电磁成形时线圈受力的研究

成形线圈设计是电磁成形工艺的关键技术之一,为了有针对性地进行防破设计,提高线圈的使用寿命,采用数值模拟的方法研究了螺线管线圈和阶梯形线圈电磁胀形时的磁场,得到了成形瞬间的磁力线分布和线圈受到的磁压力分布.结果表明:线圈、工件的结构参数和相对安装位置对线圈的磁压力分布影响很大;将受力分布引入成形线圈设计,有效地提高了工艺实验中线圈的使用寿命.     

并联制冷机组均油均压管振动应力影响因素分析

在并联制冷机组油路系统设计改进过程中,均油均压管振动频率、启动应力及运转应力等出现测定不良的情况.为了解决此类问题,本文通过将各影响因素不同水平的实测数据进行对比分析,得出结论：影响配管振动应力的主要因素有配管形式、铜管壁厚、管口形式、支架形式以及管卡形式等.此结论可以为设计及质量管理人员确定解决问题的方向提供借鉴.     

CPC热管真空管式热水器实验研究

研制了一种CPC(复合抛物面聚焦)热管真空管式太阳能热水器。该热水器在普通玻璃真空管热水器的基础上耦合热管技术,并增加了CPC聚光板。对该热水器与全玻璃真空管太阳能热水器进行了热性能对比实验研究。结果表明,在300 W/m2~800 W/m2日照条件下,该新型热水器单位面积集热功率最高可达610 W/m2;平均集热效率约为80%,比全玻璃真空管太阳能热水器的瞬时效率高10%~20%;导热介质的最高温度达到103℃。证明增加CPC聚光板及运用导热油可有效提高集热品位,利用热管技术可解决严寒地区的抗冻问题,所以,CPC热管真空管式太阳能热水器将具有较广阔的市场前景。     

Steady-state one-dimensional breakdown of thermoplastics under heavy fluxes of radiant energy

It is shown that part of the breakdown in specimens of polystyrene (PS) and polymethylmetacrylate (PMMA) is nonthermal. The thermal breakdown parameters as well as characteristics of the vapor-condensate zone and the linear velocity of the breakdown front have been measured. The results of the experiment are interpreted theoretically.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 23, No. 2, pp. 257–266, August, 1972.     

管件长度对电磁成形线圈放电电流的影响

为研究电磁成形过程线圈放电电流的变化规律,在放电回路分析的基础上,采用试验分析与代数解析相结合的方法研究了管件长度对线圈放电电流的影响.试验结果表明:随着管件长度的增加,线圈放电电流的幅值和频率均增加.通过解析方法定性分析管件长度对线圈放电电流的影响,其结果与试验结果一致.管件长度不同时,放电回路的等效电感不同,管件长度与等效电感成反比.将管件和成形线圈等效为圆柱线圈可定性分析电磁成形系统的电感和互感.     

An analysis of the transient stresses in a heavy duty switching unit

An analysis has been made of the transient bending and shear stresses set up in the drive shaft of an 11 W ring main switch unit manufactured by South Wales Switchgear Ltd. The analysis compares theoretical bending and shear stress plots along the main shaft with experimental values obtained from electrical resistance strain gauges.     

真空管吸收涂层的吸收比对全玻璃真空管的热性能影响的试验分析

全玻璃真空太阳集热管是太阳能热利用系统的重要组成部分,其性能参数的优劣直接影响到太阳能热利用系统的热性能、耐久可靠性和节能效果。文章从真空管基本结构和工作原理的介绍出发,对影响真空管性能的光学性能、热性能等关键技术参数及玻璃管材料、真空性能等其他技术要求的研究进展做了详细分析,并在长期从事科研和检测工作的基础上,给出了提升真空管的产品性能可从玻璃管生产优化、新涂层开发、真空性能加强、技术创新、先进设备开发、标准修订等方面的建议。

     

新型大型蓄能式空气源热泵热水机组的探讨

针对国内外传统空气源热泵热水器的研究和应用状况,分析其推广应用存在的弊端。将空气源热泵热水机组与电力的移峰填谷相结合、蓄冷蓄热相结合,并采用新型蓄能式融霜方式,提出一种大型蓄能式空气源热泵热水机组的新流程。详细阐述新系统的工作原理、全年多种高效运行模式以及与常规系统比较所具备的特点,并针对新系统今后的应用和发展提出需要解决的关键技术。     

空气源热泵热水机组模糊除霜控制器的研究

设计空气源热泵热水机组模糊除霜控制方案,并从输入量模糊化模块、模糊推理模块、除霜控制模块、除霜监控、规则调整模块等方面对模糊除霜控制器进行深入研究,构建完善的控制流程,并进行实验研究,其结果表明该控制器有助于空气源热泵热水机组除霜性能的改进和提升,同时也提高了机组在低温、高湿工况下运行的稳定性和对环境的广泛适应性。     

Effects of a magnetic field on heavy oil residues at high temperatures

Results are presented on the effects of electromagnetic fields on heavy oil residues.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 51, No. 6, pp. 990–993, December, 1986.     

A new approach for synthesis of well-crystallized Y zeolite from bentonite and rice husk ash used in Ni-Mo/Al2O3-Y hybrid nanocatalyst for hydrocracking of heavy oil

A series of Ni-Mo/Al₂O₃-Y hybrid nanocatalysts were synthesized for hydrocracking of heavy oil. The well crystallized Y zeolite was synthesized from mineral bentonite and rice husk ash by a two-step synthesis method. The solution combustion method was applied to develop a fast and simple technique for preparing of alumina-supported NiMo catalyst with high hydrodesulfurization activity. Such activity may be due to the morphological and textural modification as a consequence of the release of a high amount of exhaust gases during the combustion process. The XRD analysis revealed that the P zeolite was a competitive phase presented in the obtained product that could be eliminated using a two-step synthesis method. Compared to a one-step method, the pore volume and external surface area of the synthesized zeolite by the two-step method increased by 74 and 62%, respectively. The hydrocracking results illustrated that the synthesized zeolite was able to convert 66% of heavy oil to lighter products and reduce the viscosity up to 60%. Furthermore, the amount of sulfur removal was found to be 58%. The spent catalyst characterization suggested that the type of deposited coke was hard coke with the unsaturated aromatic ring which could be responsible for the pores blockage after the cracking reaction.