原油成品油管道同沟敷设新技术中的热力分析

采用非结构化有限容积法,对原油成品油双管同沟敷设新技术进行数值模拟,详细研究了不同管间距下成品油管道对加热输送原油管道的热力影响,尤其是对热油油温的影响。     

The vibration analysis model of pipeline under the action of gas pressure pulsation coupling

Pipeline vibration is the main factor that makes pipeline system can't work properly. And the pressure pulsation of the air flow is one of the important factors, which causes the gas pipeline vibration. In order to further understand the influence of the pressure pulsation on the pipeline system vibration, the analysis model and calculation method of the pressure pulsation and pipe coupling interaction are established. Taking transferring matrix method to calculate the natural frequency of gas column, and using the stiffness matrix method to obtain the pressure pulsation. According to the interaction force between the pressure pulsation and the pipeline wall, the equation of forced vibration of pipeline is established, which can obtain the variation trends of vibration displacement and velocity of pipeline system. Using field test data to verify the theoretical calculation results, the results of the calculated values and test values are within error limits. The results can provide a theoretical basis for the safety evaluation of oil and gas pipeline, and provide a reference for the pipeline mechanical properties research.     

船舶典型管路系统低噪声设计研究

针对船舶典型管路系统振动噪声控制涉及元件多、技术要求高和施工难度大等难题,提出一种综合考虑管路系统结构参数、流体性能和实船安装因素的低噪声设计方法。首先,采用传递矩阵法建立直管、弯管、法兰、弹性支撑、挠性接管等典型管路元件的传递矩阵,给出管路系统的固有频率和振动响应;其次,设计管路系统计算模型,通过ABAQUS有限元仿真得到挠性接管和弯管对管路系统的影响规律;最后,开展管路系统低噪声设计试验。仿真分析和试验结果表明,管路系统低噪声设计模型是有效的,并给出工程应用中挠性接管、弯管等典型管路元件低噪声安装的建议。     

The Characteristics of a Gas Pipeline in the Presence of Hydrate Deposits

The paper deals with the flow of a wet hydrocarbon gas in a pipeline, which is accompanied by the process of gas-hydrate deposition (sclerosis) on the internal surface of the pipeline. The pipeline sclerosis may occur in two ways, namely, under conditions of thermal balance and under conditions of water deficit. In so doing, in the initial region behind the pipeline cross section in which the condition of gas-hydrate formation sets in, the process of deposition exhibits the former pattern. The hydrate formation causes the flow depletion of water and, as a result, starting from some cross section, the pipeline sclerosis takes the latter pattern.     

不同支撑刚度对输流管道系统动力学特性的完整性影响

输流管道系统包含的支撑是影响其动力学特性完整性的重要因素之一,支撑的位置变化和刚度变化都会引起输流管道的动力学特性的改变。基于输流管道的流固耦合作用,将支撑简化为等效质量和六个方向刚度系数的弹簧,分析不同刚度系数下输流管道的固有频率和相对振幅值,以分析和评估不同支撑刚度对输流管道系统动力学特性的完整性影响。结果表明,选择合适的支撑刚度对完善输流管道动力学特性的完整性有着重要的作用。     

Safety evaluation of a collapsed turbine wind on the buried pipeline

In order to study the impact of the collapse of a wind turbine on the buried pipeline, three conditions are explored. With the formula of penetrating power, the impact force and impact depth resulted from the wind turbine collapse are estimated for safety evaluation. The evaluation results show that if the impact is only from the wind turbine collapse, the pipeline is not damaged, but it is difficult to ensure the normal operation of the pipeline. If the damage is caused by the wing turbine with blades or only by blades, the downward penetrating force is so large that the pipeline is directly sheared off. Although the probability of wind turbine collapse is low, it is harmful to the pipeline and appropriate protective measures should be adopted.     

Permafrost and cold-region environmental problems of the oil product pipeline from Golmud to Lhasa on the Qinghai-Tibet Plateau and their mitigation

The 1076-km-long Golmud-Lhasa oil product pipeline is located closely parallel to the highway constructed 20 years earlier within the relatively narrow north-south engineering corridor crossing the treeless central area of the Qinghai-Tibet Plateau. Much of the corridor is at elevations exceeding 4500 m and high-elevation, generally warm permafrost is encountered in more than one-half of the length. The pipeline, transporting mostly diesel, motor and aviation fuels at ambient temperatures, is 159 mm in diameter, has a wall thickness of 6 mm and was buried in a trench at a nominal depth of between 1.2 and 1.4 m. The soils encountered, mostly periglacial sands, silts and gravels, often have elevated saline contents and are subject to severe wind erosion and occasional monsoon flash flooding conditions. During its first quarter century of operation, the pipeline suffered at least 30 significant leaks and four pipeline ruptures. About 337 km of the pipeline was extensively rehabilitated, including relocations or replacements in major problem areas and, where feasible for an existing pipeline, improvements in pipeline protection during 2001-2004. It was supposed to safely operate for another 30 years with proper checks and needed repairs. This paper provides a review on the history of the permafrost and cold regions environmental problems of the pipeline, and their major rehabilitation, repairs and problems in the future, which might have useful implications for similar oil product pipeline at high elevations or permafrost regions.     

峰谷电价体制下东北输油管网日输油优化研究

东北原油长输管网是中国规模最大的地区性原油运输系统,就该管网基于峰谷电价体制下的运行现状,建立了线性规划数学模型,提出了日输油计划优化问题,并以铁秦线为例进行分析;初步揭示了峰谷电价体制下日输油计划方式的一些基本规律, 表明在该体制下东北管网具有一定的节能降耗潜力.但该方式在一定程度上受到管道本身运行特性的约束 ,与热油管道相比它更适合于等温管道.     

X100管线钢在含SRB的盐碱土壤溶液中的SCC行为

为证实SRB对X100管线钢在土壤中应力腐蚀行为的影响,采用慢应变速率拉神(SSRT)实验和SEM研究了X100管线钢在含有SRB的海滨模拟盐碱土壤溶液的应力腐蚀开裂行为.结果表明:X100钢母材和焊缝在无菌的海滨模拟盐碱土壤溶液的断裂模式为穿晶+沿晶SCC混合断裂,而在有菌的海滨模拟盐碱土壤溶液的断裂模式为穿晶SCC断裂;且X100钢母材和焊缝在无菌的海滨模拟盐碱土壤溶液中的SCC敏感性高于有菌时的,说明SRB的存在抑制了X100钢的脆变,导致X100钢的SCC敏感性降低.     

Development of freezing-thawing processes of foundation soils surrounding the China-Russia Crude Oil Pipeline in the permafrost areas under a warming climate

The proposed China-Russia Crude Oil Pipeline (CRCOP) will be subjected to strong frost heave and thaw settlement of the surrounding soil as it traverses permafrost and seasonally frozen ground areas in Northeastern China. The freezing-thawing processes, the development of the maximum frozen cylinder in taliks and thawed cylinder in permafrost areas, and the variations in the maximum freezing depths under the pipeline in taliks and thawing depths in different permafrost regions near Mo'he station, the first pumping station in China, were studied in detail using numerical methods in this paper. The inlet oil temperature at Mo'he station was assumed to vary from 10 to − 6 °C in a sine wave form during the preliminary design phase. Research results showed that the freezing-thawing processes of soils surrounding the buried pipeline had distinct differences from those in the undisturbed ground profile in permafrost areas. In summer, there was downward thawing from the ground surface and upward and downward thawing from the pipeline's surface once the temperature of the oil rose above 0 °C. In winter, downward freezing began from the ground surface but upward and downward cooling of the cylinder around the pipeline didn't begin until the temperature of the oil dropped below 0 °C. However, in the undisturbed ground profile, downward thawing from the ground surface occurred in summer and downward freezing from the ground surface and upward freezing from the permafrost table occurred in winter. The maximum thawing depths and thawed cylinder around the pipeline in warm permafrost enlarged with elapsing time and decreasing water content of the soils. In taliks, the maximum freezing depths and frozen cylinder around the pipeline kept shrinking with elapsing time and increasing water content of the soils. The freezing-thawing processes and development of the thawed and frozen cylinders around the pipeline were muted by any insulation layer surrounding the pipeline. Insulation had better thermal moderating on the heat exchange between the pipeline and the surrounding soils during the early operating period. But its role slowly weakened after a long-term operating. Research results will provide the basis for assessment and forecasting of engineering geological conditions, analysis of mechanical stability of the pipeline, foundation design, and pipeline construction and maintenance.     

埋地输油管道外防腐层破损处的检测

采用RD PCM地探仪对埋地输油管道外防腐层的露铁点进行不开挖检测 ,检测准确率达 10 0 %。其中焊接接头处未做防腐处理和防腐层质量不合格占露铁点的 80 %,硬物挤压损坏防腐层占 2 0 %。对管道开挖维修后回填 ,经地探仪二次检测 ,证明管道已处于安全保护状态。最后提出了管道施工工程中应注意的问题。     

拖锥系统管路延迟时间分析研究

延迟时间是拖锥系统的重要技术指标,为实现拖锥系统管路延迟时间的精准预测,本文基于连续性方程和动量守恒方程对拖锥系统进行理论建模,同时考虑不同流动状态管路中粘性阻力的影响,模型的适用性得到改善,同时通过试验验证了模型的准确性,使模型更具备实际工程应用性.在此基础上,研究了管路自身结构参数和环境参数对拖锥系统延迟时间的影响...     

柱面SH波作用下管道的动应力集中研究

在地下工程爆破开挖过程中,爆破地震波对管道安全的影响是十分重要的。为了更好的研究柱面SH波作用下管道的动应力集中情况,以爆破地震波中的柱面SH波作为研究对象,推导了柱面SH波作用下管道内壁上动应力集中系数(DSCF)的解析解。通过宝通禅寺地下通道爆破开挖工程,讨论了归一化爆心距r^*和入射波频率f对DSCF的影响。结果表明,由于管道与周围土层剪切模量差异较大,管道上的动应力集中系数普遍较大;从DSCF分布的角度来讲,当r*和入射波频率f对DSCF的影响。结果表明,由于管道与周围土层剪切模量差异较大,管道上的动应力集中系数普遍较大;从DSCF分布的角度来讲,当r^*<5时,柱面波与平面波的差异较大,但当r*<5时,柱面波与平面波的差异较大,但当r^*>5时,柱面SH波基本可以认为与平面SH波等价;低频入射波对管道的安全更为显著,特别是入射波频率与管道自振频率接近时,管道受到的影响最为严重。     

Forecasting the oil temperatures along the proposed China-Russia Crude Oil Pipeline using quasi 3-D transient heat conduction model

The China-Russia Crude Oil Pipeline (CRCOP) faces significant challenges due to differential frost heaving and thaw settlement resulting from significant variations of oil temperatures along the pipeline. Oil temperature distribution along the pipeline during the long-term operation period is a very important factor in pipeline foundation design under future climate warming and various frozen soil conditions. It is important for the assessment and prediction of differential frost heave and thaw settlement of the pipeline foundations soils, forecasting the development of the seasonal and inter-annual frozen and thawed cylinders around the operating pipeline, stress-strain analysis of the pipeline, and mitigation of subsequent frost hazards. A quasi three-dimensional computational model was developed to predict the oil temperature along the pipeline. It was verified by analytic solutions of the minimum oil temperatures along the route provided by the Daqing Oilfield Engineering (DOE) Co. The oil temperatures were predicted and analyzed for two proposed annual oil flow rates of 15 million tons (0.3 mbpd) and 30 million tons (0.6 mbpd) with and without mitigative measures (only pipe insulation was considered here) during the operation period. Also, the inter-annual variations of oil temperature at key typical locations were investigated to understand the impact of climate warming. The results indicated that the maximum oil temperature cools southwards, but the minimum oil temperature warms southwards (with the inlet oil temperatures from − 6 to +10 °C). However, the average annual oil temperature decreases southwards in the northern part of the pipeline, then it starts to slowly increase. The amplitudes of oil temperature change will decrease southwards. Oil temperatures will slightly increase with elapsing time due to the imposed boundary conditions of climate warming. The oil temperatures with a lower flow rate vary more significantly than that with a higher flow rate because the oil temperature with a low flow rate is more affected by the thermal regime of the surrounding soils and the external environments. Insulation around the pipeline tends to reduce the oil temperature variations along the pipeline during pipeline operation period. Therefore, pipe insulation can effectively reduce the development of frozen and thawed cylinders in the permafrost zone. The phase change of water in soils around the pipeline has a distinct influence on the oil temperature during the freeze-thaw transition periods. The oil temperature tends to be equal to the ambient ground temperature around the pipeline with southward distance and with elapsing operation time. The pipeline oil temperature is controlled by the incoming oil temperature and the surrounding ground temperature before the equalization. It would be mainly controlled by the ground temperature around the pipeline afterwards.     

管道失效判据简析

在外部载荷超过管道所能承受范围时管道即发生失效。通过研究管道在外力作用下的力学性能,有助于确定管道失效时的应力或应变的临界值,根据是取应力还是取应变作为衡量管道失效时的指标,分别有基于应力的失效判据和基于应变的失效判据。合理选用管道失效判据,可以节约管道投资、延长管道使用时间。简介材料应力—应变曲线的一般特征,分析管道基于应力的失效判据和基于应变的失效判据的方法。     

330MW机组主蒸汽管道振动分析与治理

通过振动测量和分析,掌握了某电厂330 MW机组主蒸汽管道的振动特性,据此并结合管道的实际情况,制定了加装减振装置、加强管系约束、增大管系刚度的振动治理方案.结果表明:经振动治理后,该主蒸汽管道振动显著降低,治理效果显著.     

Modeling the behavior of natural gas pipeline impacted by falling objects

A numerical approach, based on the finite-element method was established in this paper to simulate impact behavior of buried gas pipeline. A three-dimensional elastic perfectly plastic soil model with plane strain conditions was employed in this analysis. The influence of relative stiffness of pipeline–soil, buried depth of pipeline and impact energy on the stress distribution of buried pipelines was discussed. The analysis results showed that the maximum pipeline stress decreased with the increase of the relative stiffness of pipeline–soil; however, the penetration depth was independent of the relative stiffness of pipeline–soil. Pipeline stress decreased with the increase of buried depths and began to stabilize when the buried depth was more than 3 m. The results of impact load and penetration depth considering the plasticity of soil were much larger than those not considering it. To minimize the discrepancy of results between the current approaches and the actual situation, a new method was put forward to improve the accuracy of the proposed formula computing impact load and penetration depth. The results from the new theoretical method were closer to those from the finite element analysis and tests.     

Simulation Study on the Typical Influencing Factors for Negative Pressure Wave in Liquid Pipeline Leakage

We conduct simulation study on the typical influencing factors for negative pressure wave in liquid pipeline leakage.We first analyse the liquid pipeline leakage detection based on negative pressure wave method and obtain the essential simulation parameters.Then based on the physical model of pipeline and by introducing leakage boundary condition,we simulate the variation of pressure and flow rate in pipeline after leakage,the influence of leakage scale and leakage position on the pressure and flow rate in ...     

管道锈蚀射线检测技术

目的：研究高分辨率的X射线数字成像技术在管道锈蚀检测中的应用。方法：将射线光线转换技术，慢成像技术，非线性滤波等计算机图像处理应用于管道锈蚀成像。结果：利用该技术可真实地显示管道内部结垢，堵塞，腐蚀等情况，结论：利用上述结果可分析和判定管道的运行状态，测定管道腐蚀速率，评估管道安全可靠性，合理确定管道使用寿命。     

基于蒸汽压方程下的管道煤气流量在线计量系统

针对目前管道煤气计量中测量精度差或无法计量等问题，基于水的蒸汽压方程下，建立了工况下新的管道煤气流量计量模型和在线计量系统，应用表明，该在线计量系统不再要求建立管道煤气不同温度下所对应的水蒸汽饱和压力数据库，从而可以大大简化管道煤气流量计量软件，可快速准确地实现管道煤气流量实时在线计量。