近缆抛锚技术在海南联网二回路由勘察中的应用

介绍了近缆抛锚技术在海南联网二回路由勘察中的应用方法、实施过程,在确保海南联网一回海底电缆安全稳定运行的前提下,完成了海南联网二回路由勘察施工作业,极大地降低了因抛锚施工给运行中的海底电缆带来的安全风险。     

海底管道连接工艺研究

海底管道连接是构建完整的海底管道系统不可或缺的作业环节。文中介绍了海底管道连接所需机具,对各种连接器优缺点进行了比较分析,详细阐述了管道连接工艺流程,包括连接定位测量、水上预制、跨接管及作业机具下放、水下连接等,最后对不同连接方法进行了总结和比较。     

海南联网工程500 kV海底电缆保护区安全分析及船只抛锚信息收集综述

海底电缆在运行中除了时刻遭受着潮汐、波浪、冲刷及地震等自然条件的作用外,还受到海底物质摩擦、人类活动破坏的威胁。目前,海缆95%以上的故障都是人类对海洋的开发活动造成的,如捕鱼和拖锚行船等。现介绍了海底电缆保护区船只抛锚后现场应急处置信息收集概况,希望能帮助有关人员有效判断船只锚点与海缆距离,从而确保海缆安全稳定运行。     

关于海底管道配重层防滑施工技术的研究

受制于施工工艺,海底管道在海上铺管施工过程中,通常都要受到几十乃至几百吨的轴向张力的作用,同时,还要承受大的弯曲变形的作用。如果配重层与防腐蚀层之间的剪切应力传递能力不够大,那么就很容易出现防腐海底管道配重层滑脱的问题。分析了海底管道配重层常用的防滑工艺,针对一海底管道项目施工的工程实例,就海底管道配重层防滑施工改进技术进行了深入的研究。试验结果表明,在防滑施工改进之后,试验荷载的值即便达到了805.6kN,防腐蚀层与混凝土层之间也没有发生任何的位移,实际剪切强度为0.24MPa,远远高出设计和工程的要求。     

含腐蚀海底悬空管道的安全研究

海底管道悬空在滩浅海海域是常见的现象,为确定当悬空管道存在腐蚀的情况下,对海底管道的安全评估所产生的的影响,通过有限元分析的方法,研究了腐蚀在海底悬空管道不同轴向位置上,对海底管道的受力影响。     

海南联网系统海缆监视告警区风险预控要素研究

500kV福港线海底电缆监控系统(以下简称"海缆监控系统")由海底电缆监视系统、海底电缆决策系统、海底电缆控制系统、海底电缆辅助系统四大系统统一构成,该系统集硬件、软件于一身,实现对500kV海底电缆的全方位监控,以保海底电缆安全。现根据海南联网西戎海底电缆监视告警区过往船只频密、抛锚规律及区域船舶作业特点,得出海缆监控系统决策子系统中需要考虑的风险预控要素。     

大型商用飞机撞击载荷对核电厂管道的影响分析

大型商用飞机撞击核电厂时,国内外相关机构和学者对撞击载荷、撞击毁伤效应、厂房结构仿真方面研究较多,但冲击振动对管道的影响分析方面研究非常少。选取某核电厂一个管道单元,借助管道分析软件PIPESTRESS对管道单元开展反应谱分析,获得大型商用飞机撞击谱下的管道响应。将管道在大型商用飞机撞击谱和地震谱下的响应进行分析,分析管道在大型商用飞机撞击谱和地震谱下的响应差异;对大型商用飞机撞击载荷评定准则进行探讨,为后续管道抗击大型商用飞机撞击设计提供支持。     

水下金刚石绳锯机技术方案分析与设计

介绍了金刚石绳锯机的基本组成和工作原理,通过对国外海洋工程施工中金刚石绳锯机作业技术方案的分析,设计了适于海底油气管道切割的水下金刚石绳锯机。针对丝杠在水下易腐蚀的缺点,提出了利用连通器原理对丝杠进行密封的方法。这种类型的水下金刚石绳锯机将在海底油气管道维修工程中发挥更有效的作用。     

腐蚀海底管道剩余强度的可靠性模型及评估研究

为了制订行之有效的海底管道检修方案,有效地保障海底管道的安全运营,极有必要对腐蚀海底管道的剩余强度进行可靠性评估。本文首先阐述了海洋环境对海底管道腐蚀的影响因素,其次建立了腐蚀海底管道可靠性模型;同时还以某腐蚀海底管道为例,进行了可靠性评估,为海底管道的维护管理提供了科学的依据。     

基于ANSYS的海底双层输油管道悬空段的受力和变形分析

针对海底双层输油管道的悬空段的受力和变形问题,考虑泥沙对管道的作用力,引入过渡段,采用ANSYS软件建立了悬空管道的有限元模型。通过计算分析得到了悬空长度对管道受力和变形的影响规律,在此基础上得出了允许的最大悬空跨距。分析结果为海底双层输油管道的失效判别提供了数据支持,对于海底管道的悬空分析与治理具有重要的意义。     

浮拖过程海底管道力学分析

海底管道施工质量直接关系到海底管道能否长久地安全运行,对施工期间各种环境载荷、施工载荷作用下海底管道上的应力进行计算分析是确保海底管道施工质量不可缺少的重要手段.从海洋管道漂浮拖运过程受力-极限情况入手,建立数学模型,首次应用五弯矩方程解决海洋管道在拖运过程中的受力问题.并开发了实用程序,算例表明:计算分析结果满足实际应用要求.     

带轴向表面裂纹海洋管道的断裂计算与可靠性评估

针对带轴向表面裂纹海洋石油管道,利用权函数方法,给出计算裂纹前沿应力强度因子的积分表达式,进而导出满足工程精度要求的应力强度因子的实用计算公式.在断裂分析的基础上,基于概率统计理论,采用极限分析方法为带裂纹海洋石油管道建立断裂可靠性评估方法,给出断裂失效概率和可靠度的计算公式,并给出典型算例的数值计算结果.     

基于滑动矩形窗的锚固螺杆超声波信号回波搜索算法

提出一种简单的回波搜索法——滑动矩形窗回波搜索算法,该法可以排除因数据偶然突变而引起的搜索错误,通过对现场采集的1万多条数据处理分析,能取得很好的效果。     

DEVELOPMENT OF CALCULATING MODEL APPLICABLE FOR CYLINDER WALL DYNAMIC HEAT TRANSFER

In the calculation of submarine air conditioning load of the early stage, the obtained heat is regarded as cooling load. The confusion of the two words causing the cooling load figured out is abnormally high, and the change of air conditioning cooling load can not be indicated. In accordance with submarine structure and heat transfer characteristics of its inner components, Laplace transformation to heat conduction differential equation of cylinder wall is carried out. The dynamic calculation of submarine conditioning load based on this model is also conducted, and the results of calculation are compared with those of static cooling load calculation. It is concluded that the dynamic cooling load calculation methods can illustrate the change of submarine air conditioning cooling load more accurate than the static one.     

Effect of operation on the stressed state of the piping of compressor stations located in different regions

Due to the increased operating time of operated compressor stations (CSs) and the current safety requirements, the engineering state of the pipelines of CSs must be surveyed to confirm the possibility of their further operation (extension of the operating life). The available factual material shows that the failure of an operated pipeline is either directly related to the effect of an unrated static or dynamic load that was the primary reason for the failure or is due to the presence of flaws that facilitate the appearance of an unrated load. The presence of an enhanced level of stresses may be a consequence of several factors, including errors in design; violation of the rules of assembly of structural elements; and operating conditions related to variation in the height positions of pipeline segments due to soil instability or subsidence and also due to buckling of supports. The latter factors are traditionally indicated as probable causes of overload for pipelines located in northern regions that are located on sandy soils and under conditions of deep freezing of soils. An evaluation of the actual level of stresses of production pipelines of compressor stations (CSs) and a comparison of the parameters of the stressed states of CSs located in different regions enables one to assess the effect of climatic factors on the operating conditions of pipelines. In this study, based on an analysis of the parameters of the stressed state obtained using magnetic methods for measuring stresses, the load level of pipelines is assessed on a scale from individual segments of a pipeline to a comprehensive assessment of plant piping.     

Development of Third-Party Damage Monitoring System for Natural Gas Pipeline

In this paper, we develop a real time monitoring system to detect third-party damage on natural gas pipeline. When the damage due to third-party incidents causes an immediate rupture, the developed on-line monitoring system can help reducing the sequences of event at once. Moreover, since many third-party incidents cause damage that does not lead to immediate rupture but can grow with time, the developed on-line monitoring system can execute a significant role in reducing many third-party damage incidents. Also, when the damage is given at a point on natural gas pipeline, the acoustic wave is propagated very fast about 421.3 m/s. Therefore, the data processing time should be very short in order to detect precisely the impact position. Generally, the pipeline is laid under ground or sea and the length is very long. So a wireless data communication method is recommendable and the sensing positions are limited by laid circumstance and setting cost of sensors. The calculation and monitoring software is developed by an algorithm using the propagation speed of acoustic wave and data base system based on wireless communication and DSP systems. The developed monitoring system is examined by field testing at Balan pilot plant, KOGAS being done in order to demonstrate its validity through reactive detection of third-party contact with pipelines. Furthermore, the development system was set at the practical pipelines such as an offshore pipeline between two islands Yul-Do and Youngjong-Do, and a land branch of Pyoungtaek, Korea and it has been operating in real time.     

Impact wear of MgO single crystals II. Impact and wear damage

The impact wear damage of MgO single crystals was investigated under an impact load of 60 kgf. Two types of impact damage, a zero wear process and a measurable wear process, are distinguished. The impact scar shows three types of cracks: subsurface cracks parallel to the surface, and tangential and radial cracks on the surface. In the early stages of the wear process the impact scar is surrounded by surface and subsurface cracks and grows as a unit square cell; wear occurs at the scar bottom and on the scar wall. Consequently the profile of the wear scar changes to a hemispherical or parabolic shape. The zero wear limit under each impact load is determined from the static contact stress and the number of impacts.     

深水海底管道的直缝埋弧焊钢管特点及DWTT性能影响因素分析

分析了深水海底管道计的技术特点,并就深水海底管道的较大壁厚、直缝埋弧焊钢管的变形率以及微观组织的均匀性,对落锤撕裂试验(drop weight teat test,简称DWTT)止裂性能的影响进行了分析,认为采取减小有效晶粒尺寸和降低夹杂物含量等措施,均有利于提高深水海底管道DWTT的断裂韧度。     

泡沫夹层复合材料的低速冲击损伤及剩余强度的数值模拟

基于渐进累积损伤理论和数据传递分析方法,对泡沫夹层复合材料的低速冲击以及冲击后的压缩破坏过程提出了一种全程数值分析方法,即对泡沫夹层复合材料的冲击以及冲击后损伤的泡沫夹层复合材料在压缩载荷下损伤扩展的全过程进行数值模拟分析。结果表明:由于该方法避免了以往学者对冲击后夹层板损伤状态所做的人为假设,把冲击后的预测损伤直接传递用于剩余强度的研究,从而提高了最终破坏载荷和剩余强度的预测精度,数值模拟结果与已有试验结果吻合较好。