输气管道仿真中摩阻系数相关参数设置

摩阻系数是管道仿真软件水力计算的重要参数,为了提高模拟准确度,研究优化设置软件中的摩阻计算公式和参数很有意义。编程计算了Weymouth、Pan(A)、Pan(B)、AGA、Colebrook、Nikuradse公式在不同相对粗糙度和雷诺数下的摩阻系数,和Moody标准图谱比较精度后获得了各公式的适用范围,发现Colebrook公式的适用范围和精度最优,AGA公式次之,其他公式则适用于不同的范围。结合3条真实管道与现场实际工况,在模型仿真运行时动态调整绝对粗糙度,反算出实际值0.010、0.015和0.013 mm。故绝对粗糙度推荐值为0.010～0.015 mm。

输气管道仿真模型校正技术研究进展

为了解决输气管道仿真系统存在计算值与实际值偏差的问题,对解决该问题的模型校正技术展开国内外调研。提出造成仿真计算不精准的三个主要误差来源:输入参数测量误差、缓变参数误差、手工输入误差。最后通过分析国内外仿真模型校正技术研究现状,建议在动态仿真的基础开展输气管道的模型校正技术研究,以避免输气管道系统数据波动带来的误差。

基于WebGIS的管道仿真模型构建

油气管道仿真作为保证油气管道安全、高效、平稳运行的一项重要技术,多注重提升仿真计算引擎算法的精度和效率,而对管道模型建模过程的研究较少。管道模型建立过程复杂易错,不便于用户使用。为提高简单易用的可视化管道仿真模型的构建能力,将WebGIS技术引入管道模型构建过程,重构了管道模型数据组织方式,设计了基于坐标的管道模型构建系统,取得了良好的使用效果。

内壁涂层钢质油气管道流体压降损失仿真研究

采用流体仿真软件对压力管道内壁环氧涂层和无涂层钢制管道进行流体计算研究,对比半经验公式流体计算结果,研究在不同粗糙度下的管道介质流动特性。结果表明:流体计算与仿真计算两种方法得到的管段压降损失和节能效率基本一致,为环氧涂层的优异节能性能表现提供可靠依据。通过流体仿真计算,可直观地获取流体在管道中的流动状态和规律,全面掌握压力管道介质流场分布、流体特性、涂层影响、管道性能等信息,可对内壁涂层钢质压力管道的流体流动进行深入分析和优化,为实际应用中的管道运行提供重要的支持和指导。

基于UML的管道虚拟仿真系统设计

基于面向对象开发过程,构造了管道虚拟仿真系统总体框架,建立了管道虚拟仿真应用子系统的需求分析与系统设计UML模型。从管道虚拟仿真系统OOA到OOD阶段,分别体现了软件复用的特点,能够实现在可复用的UML模型基础上进行过程工业的管道虚拟仿真系统开发。模型可重用性好,已得到实际应用验证。

基于先验知识的管道流体快速仿真技术研究

随着数字孪生技术的兴起和发展,数据快速传输应用的需求得到了极大的关注。在工业应用领域,存在因复杂环境下传感器无法在适当位置安装,造成孪生体数据不完整的情况出现。针对管道流体状态这类不易实测的信息,常使用有限元仿真的方法获取物体各监测点的变化数据,但传统的有限元仿真分析需要耗费大量的时间成本和计算机资源,无法适用于对数据实时传输有高要求的管道数字孪生系统。文中将多组条件下获得的仿真结果作为先验知识建立仿真数据库,运用K近邻的思想在库中查找与测试集最相似的仿真结果,以该条件下的仿真结果为基准对测试集进行完整数据预测,得到测试条件下的完整仿真数据。实验结果表明,文中所提方法与传统有限元仿真结果精度相一致,仿真效率得到巨大提升,可适用于有数据快速反应需求的管道数字孪生场景。

检漏软件在输油管道SCADA系统中的应用

目前各大型长距离输油管道系统上广泛应用SCADA系统作为自控系统.提出了基于SCADA系统的原油泄漏检测系统,不仅可以检测、显示、控制管道的工艺参数,而且可以动态仿真整个管道水力状态和实时检测管道泄漏时间、地点和泄漏量.该系统针对华北油田某采油厂输油系统,结合瞬态负压力波法和管道实时传输模型法,有效提高了管道油品泄漏检测的准确性和报警的及时性,减少了报警失误率.近两年现场运行证明该系统可靠、稳定.

城市燃气管道带气作业自动控压方法

针对现有燃气管道带气作业控压方法和技术不足,提出了一种燃气管道带气作业自动控压方法,通过此方法有效解决了带气作业中压力控制的问题。文中介绍了燃气管道带气作业自动控压工艺的工作原理,并进行了理论计算公式推导,通过建立燃气管道仿真模型,获取管路压力与流速的关系以及阀门压差与其开度和流速的关系曲线,建立了Fuzzy/PID控制模型和算法,实现了燃气管道带气作业的自动控压。该方法解决了燃气管道带气作业中用气量变化导致的管道压力波动问题,实现了燃气管道的控压与稳压,提高了带气作业的效率与安全性。

基于CFD技术管道气体流场计算与分析

基于CFD技术,运用CFD软件结合气体运动基本理论,以电子束焊接真空系统中管道设计为例,对中真空条件下气体在管道内的流动状态、速度、压力分布进行2D有限元数值模拟仿真和可视化研究,为真空系统管道参数确定和结构优化设计提供了有参考价值的数据。提出在真空系统设计选择前级泵时,为保证获得较大的抽速,达到高效与经济的效果,优先考虑主泵排气口直径与前级泵相匹配,再校核前级泵最大反压力和最大排气量,可以极大提高设计效率。

姬塬—惠安堡输油管道工程新技术研究与应用

姬塬-惠安堡输油管道工程(以下简称姬惠管道),通过运用管道模拟仿真技术、"黄夹克"保温输送工艺、SCADA系统以及在线模拟仿真泄漏检测定位技术等国内先进技术,使该管道的整体技术水平已达到了国内领先水平,本管道的设计思路以及所采用的新工艺、新技术可为今后的管道建设提供良好的借鉴作用。

姬塬—惠安堡输油管道工程新技术研究与应用

姬塬-惠安堡输油管道工程(以下简称姬惠管道),通过运用管道模拟仿真技术、"黄夹克"保温输送工艺、SCADA系统以及在线模拟仿真泄漏检测定位技术等国内先进技术,使该管道的整体技术水平已达到了国内领先水平,本管道的设计思路以及所采用的新工艺、新技术可为今后的管道建设提供良好的借鉴作用。

日仪线瞬态工况模拟分析与研究

工况仿真对于合理确定原油管道的设计方案和安全运营管理有着重要意义。通过SPS管道仿真软件对日仪原油管线遇到中间站甩泵的瞬时工况进行分析与研究,从而掌握日仪原油管道遇到事故工况时的参数变化,有助于调度管理部门指挥和优化日仪原油管线的运行方案,及时采取应急措施,保证了输油的安全进行。

基于并行计算的天然气动态模型算法

针对天然气仿真系统的运行速度不能满足实际需求这个问题,提出一种基于并行计算的天然气动态模型算法,可以将并行计算应用到管道的计算之中。该算法对原有的天然气动态仿真算法进行了两点改进:第一,将动态规划的思想用于天然气管道的流量分配之中,将天然气管道网络划分成了互不影响的不同阶段,为管道并行计算打下基础;第二,利用虚拟管道流量的方法对管道动态仿真算法的边界条件作出改进,通过改进使管道的计算不再依靠前一条管道的计算结果。为了验证改进后算法的高效性和可靠性,利用Matlab软件对该仿真算法进行实现,结果证明新算法的运算时间比现有的算法减少了60%。之后将新的算法的运行结果与现有的仿真模型和西气东输中管道的真实测量数据进行对比,其拟合度较高,误差符合实际要求。其实验结果证明该算法可以大幅度提高管道网络仿真系统的运行速度,帮助工作人员在实际情况发生变化时迅速作出决策,避免管道破裂等事故的发生,节约管道维护费用。

Simulation study of blast fume diffusion characters of driving face

Based on FLUENT software, studied the blast fume diffusion characteristics of a driving face under 8 situations, and analyzed the influence to fume diffusion of different drift length and different ventilation pipe outlet positions. Through regression analysis, functions of ventilation time to the drift length and ventilation pipe outlet position was obtained.

Global optimization for ducted coaxial-rotors aircraft based on Kriging model and improved particle swarm optimization algorithm

To improve the operational efficiency of global optimization in engineering, Kriging model was established to simplify the mathematical model for calculations. Ducted coaxial-rotors aircraft was taken as an example and Fluent software was applied to the virtual prototype simulations. Through simulation sample points, the total lift of the ducted coaxial-rotors aircraft was obtained. The Kriging model was then constructed, and the function was fitted. Improved particle swarm optimization(PSO) was also utilized for the global optimization of the Kriging model of the ducted coaxial-rotors aircraft for the determination of optimized global coordinates. Finally, the optimized results were simulated by Fluent. The results show that the Kriging model and the improved PSO algorithm significantly improve the lift performance of ducted coaxial-rotors aircraft and computer operational efficiency.

Simulation of natural gas transmission pipeline network system performance

Simulation has proven to be an effective tool for analyzing pipeline network systems （PNS） in order to determine the design and operational variables which are essential for evaluating the performance of the system. This paper discusses the use of simulation for performance analysis of transmission PNS. A simulation model was developed for determining flow and pressure variables for different configuration of PNS. The mathematical formulation for the simulation model was derived based on the principles of energy conservation, mass balance, and compressor characteristics. For the determination of the pressure and flow variables, solution procedure was developed based on iterative Newton Raphson scheme and implemented using visual C＋＋6. Evaluations of the simulation model with the existing pipeline network system showed that the model enabled to determine the operational variables with less than ten iterations. The performances of the compressor working in the pipeline network system xvhich includes energy consumption, compression ratio and discharge pressure were evaluated to meet pressure requirements ranging from 4000-5000 kPa at various speed. Results of the analyses from the simulation indicated that the model could be used for performance analysis to assist decisions regarding the design and optimal operations of transmission PNS.

Semi-physical simulation of AUV pipeline tracking

Before the task of autonomous underwater vehicle(AUV) was implemented actually,its semi-physical simulation system of pipeline tracking had been designed.This semi-physical simulation system was used to test the software logic,hardware architecture,data interface and reliability of the control system.To implement this system,the whole system plan,including interface computer and the methods of pipeline tracking,was described.Compared to numerical simulation,the semi-physical simulation was used to test the real software and hardware more veritably.In the semi-physical simulation system,tracking experiments of both straight lines and polygonal lines were carried out,considering the influence of ocean current and the situation of buried pipeline.The experimental results indicate that the AUV can do pipeline tracking task,when angles of pipeline are 15°,30°,45° and 60°.In the ocean current of 2 knots,AUV could track buried pipeline.

Simulation and Experimental Research for Piping Damper with Plunger-type Accumulator

It can be beneficial to reduce vibrations in shipboard piping, so the authors designed a new kind of piping damper with a plunger-type accumulator.Special requirements for the piping damper included low impact displacement, low speed, as well as an appropriate locking speed.Inside the damper, a plunger-type accumulator was installed and on the outside of the piston rod, a tube with exposed corrugations was added.Between the piston and the cylinder, a clearance seal was added.Using mathematical modeling, the effects of the dynamic performance of the damper's impact displacement on vibrations were observed.Changes to the clearance between the piston and the cylinder, the stiffness of the spring in the accumulator, the throttle valve size, and locking speed resistance of the damper were respectively simulated and studied.Based on the results of the simulation, dampers with optimal parameters were developed and tested with different accumulator spring stiffnesses and different throttles.The simulation and experimental results showed that parameters such as seal clearance between piston and cylinder, accumulator spring stiffness and throttle parameters have significant effects on the damper's impact displacement, low speed resistance and locking speed.

Study on Simulation Method of Pipeline Networks' Dynamic Characteristic in Hydraulic Manifold Block

In the design of Hydraulic Manifold Blocks (HMB), dynamic performance of inner pipeline networks usually should be evaluated. To meet the design requirements, dynamic characteristic simulation is often needed. Based on comprehensive study on the existing simulation methods, a new method combined of Power Bond Graph(PBG) and Computational Fluid Dynamic (CFD) is proposed. In this method, flow field of typical channels inside HMB is analyzed with CFD to obtain the local resistance coefficients. Then, with these coefficients, a new sectional lumped-parameter model including kinetic friction factor is developed using PBG. A typical HMB design example is given and the comparison between the simulation and the experimental results demonstrates the feasibility and effectiveness of the proposed method.

Multiphysics extension to physically based analyses of pipes with emphasis on frost actions

Pipes,especially buried pipes,in cold regions generally experience a rash of failures during cold weather snaps.However,the existing heuristic models are unable to explain the basic processes involving frost actions.This is because the frost action is not a direct load but one that causes variations in pipe-soil interactions resulting from the coupled thermo-hydro-mechanical process in soils.This paper developed and implemented a holistic multiphysics simulation model for freezing soils and extended it to the analysis of pipe-soil systems.The theoretical framework was implemented to analyze both static and dynamic responses of buried pipes subjected to frost actions.The multiphysics simulations reproduced phenomena commonly observed during frost actions,e.g.,ice fringe advancement and an increase in the internal stress of pipes.The influences of important design factors,i.e.,buried depth and overburden pressure,on pipe responses were simulated.A fatigue cracking criterion was utilized to predict the crack initialization under the joint effects of frost and dynamic traffic loads.The frost effects were found to have detrimental effects for accelerating fatigue crack initialization in pipes.