浅谈地震载荷条件下大型LNG储罐分析软件的设计与开发

随着LNG储罐体积的增大,其设计和分析计算复杂程度倍增,进行储罐的安全、经济设计是重要难题.大型LNG储罐设计主要依赖非线性有限元内核的数值分析软件,而现有相关软件主要依赖国外产品.针对此,本文基于国产化有限元软件平台进行了地震载荷下大型LNG储罐分析软件的顶层设计,明确了软件的主要功能内容.该软件平台大大简化了设计人...     

大型低温液化气储罐国家标准 GB/T 26978—2021修订解读

GB/T 26978—2021《现场组装立式圆筒平底钢质低温液化气储罐的设计与建造》是国内一部低温液化气储罐设计建造的基础性国家标准。为便于国内低温储罐行业建设者更好地理解2021版标准，从修订背景和意义出发，对GB/T 26978—2021的适用范围、设计依据、金属构件、混凝土构件、绝热构件以及试验干燥置换冷却等修改内容进行了全面解读，对比了新版标准与原版标准及其他相关规范的区别，给出了标准在修订中的主要变更内容，并对修改原因及差异性进行分析，以便更好地指导国内低温液化气储罐的设计建造工作，推动该标准的贯彻落实。     

全压式LPG运输船储罐国产化制造的质量控制

根据全压式LPG运输船储罐的国产化制造,从材料、工厂制造、现场组焊以及整体热处理等重要环节,阐述了LPG运输船储罐各个关键工序的质量控制要点。     

LNG储罐绝热系统设计及经济性分析

为了探究LNG储罐的最佳经济效益，从罐底、罐壁和罐顶三个方面对储罐的保冷系统进行优化，分析每种保冷材料对储罐漏热量的影响。以国内某20万m³的LNG储罐为基础，计算不同保冷方案下节约的成本，为LNG储罐的保冷设计优化提供了依据。     

固定式真空绝热深冷储罐若干问题探讨

固定式真空绝热深冷储罐(以下简称深冷储罐)在气化站、加气站、工业气体行业已广泛使用。国内各深冷设备制造企业的设计理念、制造工艺各有特点。对此,就深冷储罐在材料、结构、设计、制造过程中会遇到的若干主要问题进行分析、探讨。     

2000m3丙烯球罐国产化设计

长期以来，大型球形储罐的用材都从国外进口，国家花费了大量的外汇。自1986年国产CF－62钢问世以来，CF－62钢广泛用于各种大型球形储罐，经过十几年的探索和吸收国外的先进经验，我国球罐已走上了多样化，国产化，大型化的发展道路，本文阐述了2000m^3丙烯球罐从选用国产钢材到设计安装制造等方面的设计要点。     

宽带钢热连轧机设备技术分析

分析了我国宽带钢热连轧机和主要设备技术状况,国内设计制造情况,热连轧机的新工艺,国产化     

低温潜液泵结构与应用研究

详细介绍了大型低温储罐中低温潜液泵的典型结构,分析了叶轮、诱导轮、轴承、底阀、电缆等关键部件的结构型式,介绍了推力自平衡机构、轴承润滑和电机冷却的原理,提出了泵主要部件选材的原则、泵国产化的难点及泵在使用时的注意事项。分析表明,加强低温泵的国产化研制和应用意义重大。     

LNG储罐仪表配置及控制方案

为提高LNG储罐的安全性,某国产化示范LNG工厂项目在LNG储罐上设置罐表系统,包括:3套表面热电阻对LNG储罐的预冷和泄漏进行检测;2套平均温度计对LNG储罐内气相和液相平均温度进行检测;3套压力变送器对LNG储罐的压力进行控制;1套雷达液位计和2套伺服液位计对LNG储罐的液位进行控制;1套液位-温度-密度计(LTD)及翻滚预测软件对LNG储罐翻滚进行预测。罐表系统对LNG储罐进行全方位的监视,确保了LNG储罐的安全、平稳运行,提高了LNG储罐的自动控制水平。     

LNG储罐安全仪表系统设计

针对国内LNG接收站储罐安全运行和联锁保护系统存在的问题,系统介绍了储罐安全仪表系统的组成,通过对罐表系统、紧急关断系统、火灾和可燃气体检测系统的结构和联锁逻辑设计与研究,设计了一套完整的储罐安全仪表系统方案。为类似的安全仪表系统的设计提供了一定的参考。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.