共查询到18条相似文献,搜索用时 203 毫秒
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管道是二氧化碳捕集、利用和封存(carbon capture, utilization, and storage,CCUS)技术产业链中输运大量二氧化碳(CO2)的最优方式,但其在运行中具有意外泄漏风险。本文从实验和计算机模拟两个方面综述了国内外开展CO2管道泄漏减压、断裂扩展的研究进展,分析了相态、管材、埋地条件等初始状态对裂纹扩展规律的影响。阐述了状态方程、杂质因素、理论模型对开展实验和模拟计算研究的影响。归纳了适用于建立减压波预测模型的状态方程,开展流固耦合研究的理论方法和模拟仿真软件,设计CO2输运管道参考的技术文档。总结了当前CO2管道泄漏减压、断裂扩展控制研究方面需深入研究的科学问题,展望了亟待开展的研究内容,包括构建多元混合物状态方程在三相点、相间线的计算模型;探究裂纹裂间处CO2热物性质与裂纹断裂扩展的耦合关系;建立管道止裂准则,开发、优化CO2输运管道专用止裂器。 相似文献
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聚乙烯(PE)管道在天然气运输中应用广泛,热熔焊接是连接PE管道的主要方式之一,焊接工艺参数影响热熔接头以及管道整体的性能。文章以焊接温度、加热时间和焊接压力等工艺参数作为主要影响因素,设计正交试验,制备不同的热熔接头拉伸试样,对比分析其抗拉性能。通过数值模拟得到带卷边热熔接头拉伸试样的本构模型。结果表明:焊接温度、加热时间和焊接压力使PE管道的抗拉性能先增高后降低,焊接温度和加热时间对热熔接头的抗拉性能影响显著。PE管道热熔接头的抗拉性能比基材好。载荷-位移曲线与实验曲线较吻合。基于有限元分析和Kwon聚合物本构模型可得到PE管道热熔焊接接头准确的本构关系。 相似文献
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随着建筑业、市政及节水工程的迅速发展,我国对PE压力管道的需求越来越多,然而由于我国石化工业产发达国家相对落后,PE压力管道专用树脂,特别是高等级专用树脂对国外进口产品信赖严重。对此,以齐鲁石化等为代表的国内石化公司积极投入PE压力管道专用树脂(包括高等级专用树脂)的开发与生产,从而提升了国内石化公司的研发水平和市场竞争力。[编者按] 相似文献
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将超支化聚合物(HBP)添加到聚乙烯(PE)管道料中,采用SEM、DSC、成型工艺、拉伸实验等手段研究了不同邶P用量对PE结晶性能、注塑工艺、力学性能等的影响。结果表明:HBP的加入可使PE的结晶速率稍有提高,有效改善了PE注塑样条的表面光洁度,提高其熔体流动性,从而改善注塑加工工艺,同时提高了PE的拉伸强度。 相似文献
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大口径/厚壁PE 管道的应用情况
大口径/厚壁PE管道通常是指外径(DN)在500mm以上的实壁管道。近年来,大口径PE压力管道的需求在持续上升,PE管道由于综合性能优异而占有持续稳定的增长份额,例如无腐蚀、 相似文献
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对含有表面缺陷的钢制气瓶进行了“人工楔块”疲劳止裂试验研究。在此基础上就含缺陷结构的几各止裂技术进行了分析比较。从研究止裂机理的角度出发,提出了每种方法的应用场合,并就其止裂效果作了初步比较评价,指出了用于压力容器和管道上止裂的合理方法。 相似文献
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聚乙烯压力管道在低温时易出现裂纹快速扩展,其破坏一般都具有突发性,难以预防。本文采用小尺寸稳态试验方法,测试了在不同温度下,裂纹扩展长度随压强的变化情况,同时也测试了在不同压强下,裂纹扩展长度随温度的变化情况。通过计算分析,确定了裂纹快速扩展的临界压强和临界温度。给出了影响该试验结果的因素如温度、压力、介质、裂纹扩展速度及裂纹尖端的流体减压等。并通过试验测试了焊缝以及套筒对塑料管道开裂的影响。最后给出了塑料管道在实际运行中的一些具体的止裂措施。 相似文献
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Under uniaxial tension, high‐density polyethylene (HDPE) often fractures in a ductile manner. The fracture involves extensive necking that is known to occur in the plane‐stress condition. However, for large‐scale HDPE products like polyethylene pipe, crack can grow rapidly in a brittle manner. This type of fracture is known to be in the plane‐strain condition, which has much lower toughness than that in the plane‐stress condition. In this study, we extended the concept of essential work of fracture (EWF) to the plane‐strain condition and evaluated the fracture toughness of extruded HDPE plate. The results show that the specific work of fracture in the plane‐strain condition is also a linear function of the specimen ligament length. Therefore, the corresponding EWF value can be determined in a similar manner, that is, through linear extrapolation to zero ligament length. For HDPE, the study found that the plane‐strain toughness is about one order of magnitude smaller than the plane‐stress counterpart. Interestingly, the plane‐strain EWF value is very close to the estimated toughness of pressurized polyethylene pipe, which was reported in the literature, predicted using numerical simulation based on data from the standard small‐scale steady‐state (S4) test. POLYM. ENG. SCI. 46:1428–1432, 2006. © 2006 Society of Plastics Engineers. 相似文献
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采用应变硬化试验和锥体试验分别得到不同聚乙烯100(PE100)管材试样的应变硬化模量和裂纹扩展速率,并对它们之间的相关性进行研究,以期验证应变硬化试验法评价PE管材耐慢速裂纹扩展性能的正确性。结果表明,锥体试验中PE管材试样的裂纹扩展程度随着试验时间的增加而增大;应变硬化试验和锥体试验对不同PE管材试样的耐慢速裂纹扩展性能评价结果完全相同,应变硬化试验法评价PE管材耐慢速裂纹扩展性能的正确性得到验证;应变硬化试验不仅误差较小,而且可以区分不同牌号PE100管材耐慢速裂纹扩展性能的细微差异,评价结果相对于锥体试验要更加可靠。 相似文献
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聚乙烯承压管道及原料耐慢速裂纹增长测试标准及实验要求 总被引:1,自引:0,他引:1
聚乙烯(PE)管材在施工和使用过程中会产生裂纹并缓慢扩展,评价耐慢速裂纹增长性能包括原料测试和管材测试两部分。介绍了国际标准和国家标准中关于耐慢速裂纹增大试验的要求、原理和应用,并列举了通过切口试验加速老化评价和预测 PE 原料长期性能和使用寿命的几种方法。 相似文献
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A simple intrinsic measure for rapid crack propagation in bimodal polyethylene pipe grades validated by elastic–plastic fracture mechanics analysis of data from instrumented Charpy impact test
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Rudy A.C. Deblieck D.J.M. van Beek Mary McCarthy Petra Mindermann Klaas Remerie Beate Langer Ralf Lach Wolfgang Grellmann 《Polymer Engineering and Science》2017,57(1):13-21
Conventional test procedures, such as the S4 test to analyze the resistance against rapid crack propagation (RCP) of plastic pipe materials are characterized by usage of a lot of material, are far from saving of time and they are‐in need of special experimental set‐ups. Therefore, in the last decade, small‐scale accelerated reliable tests (SMART) are developed ‐ worldwide to overcome the disadvantage of such conventional tests. In this article, fracture mechanics based analysis of instrumented Charpy impact test data for a set of bimodal high‐density polyethylene pipe grades are compared with data of the conventional Charpy impact test. From this comparison the Charpy impact strength at ?30°C comes forth as a robust reproducible measure of the resistance to RCP and it is therefore proposed as a SMART method to rank materials with respect to RCP resistance. POLYM. ENG. SCI., 57:13–21, 2017. © 2016 Society of Plastics Engineers 相似文献
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The crack-growth behavior of a yttria-stabilized zirconia ceramic (8 mol% of cubic-phase yttria) was studied at room temperature. Double-cantilever-beam specimens were loaded with pure bending moments in a specially designed loading fixture inside an environmental scanning electron microscope. Crack-growth data were obtained from truly sharp (arrested) cracks, bypassing interpretation problems that involve crack initiation from a machined notch. The crack-growth study was conducted over a range of applied energy-release rates that allowed crack arrest on one hand and fast fracture on the other. Three energy-release-rate values were relevant: initiation of crack growth (3.5 J/m2 ), crack arrest (2.8 J/m2 ), and fast fracture (8.0 J/m2 ). At the macroscopic scale, subcritical crack growth occurred as a continuous process. In situ observations revealed that, at the microscopic scale, crack growth occurred in small jumps. The fracture mode for stable crack growth was identified to be transgranular. 相似文献
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