浆体管道内静止圆柱状型料的起动

在动量定理和能量定理的基础上,建立静止圆柱状型料在浆体管道内起动的动量方程和能量方程,并由此导出静止型料在浆体管道内的起动速度计算公式．经型料管道起动实验验证,该公式较好地描述了静止型料在浆体管道中开始起动的物理条件,能有效地推断和预测静止型料在浆体管道流中的起动速度．理论计算值和实验数据指出,静止型料在浆体管道内的起动速度,不仅和管道平均流速紧密相关,而且和浆体密度、型料形状比以及型料管道直径比紧密相关．     

一种浆体管道中气体含量的测试方法

实际的浆体输送管道中通常都含有少量的气体并会使泵的性能明显下降,现有的常规方法很难测量该气体含量。本文给出了浆体管道中气液固三相伪均质流和非均质流压力波波速计算式,数值分析表明,波速随着浆体中气体含量增加而迅速降低,并应用实例探讨了利用声速来测量浆体管道中气体含量的可行性和具体的测试方法,结果表明,通过在线测量管路中声波的速度或频率可以较准确地获得浆体中微量气体体积含量。     

水锤作用下管路系统支撑处位移与输送速度的关系

以深海采矿扬矿垂直输送硬管在水力输送过程中的管道为研究对象,分析了管道系统在水锤冲击下考虑泊松耦合时流体和结构的瞬态响应;建立了管道系统在瞬变流情况下的流固耦合模型,获得了弱约束条件下支撑处管道位移随输送速度的变化关系。结果表明:随着输送速度的提高,当管道输送系统发生水击现象时,压力发生剧烈变化,导致管道支撑点处X、Y、Z三个方向的位移均大幅增加;X、Y方向位移呈现对称性,由于Z方向与轴向一致,水击发生时其位移变化较小;随着时间的延续,Z方向位移变化愈发明显;当采用较高输送速度输送矿石浆体时,管道与两相流浆体相耦合的振幅较大。以上结果可为管道设计中的支撑结构设计提供参考。     

水平管道气固两相分层流动过程的研究

以空气作为输送动力、粉煤灰及玻璃微珠作为输送物料,对气力输送管道中气固两相流的流动特性进行了系统的试验研究.对管路系统的特性、操作条件、物料和气体的性质等影响气固两相流压力损失的主要因素进行了探讨.并在实验的基础上对两相流动的沉积速度、经济速度进行了确定.同时在对粉体受力分析的基础上建立了分层流动的物理及数学模型,通过对比数学模型计算值与试验值得出该数学模型具有一定的计算精度,能够用于指导分层流动的研究及应用.     

海底集矿机和移动输送站最小安全距离研究

海洋矿产资源的开发正由浅海向深海发展，水下输送管道作为深海采矿系统中的必备构件，其作业安全尤为重要．本文以6 000 m深海采矿工程为背景，研究了海底集矿机、海底移动输送站及连接两者的矿料输送管道的运动协调关系．首先，用悬链线理论得到输送管道的初始构形，基于有限元方法，构建了集矿机-输送管道-移动输送站系统三维动态响应模型，进而讨论了集矿机和移动输送站运动过程中，输送管道形态和应力的变化．结果表明，集矿机与移动输送站靠近时，输送管道的最大应力增长速度变快，威胁采矿系统的作业安全．基于此，提出了集矿机与移动输送站最小安全距离的概念，分析并给出了管道壁厚和材料屈服应力对最小安全距离的影响规律．     

不同浓度粉煤灰浆体管内流动规律试验研究

粉煤灰浆体在矿山及地下工程中的使用越来越广泛,而其管道运输时的过渡流速、屈服应力衰减规律及紊流水力坡度方面的研究还略显不足,开展这方面的研究有重要的应用价值。为此本文进行了体积浓度为0.422、0.441、0.462和0.492的粉煤灰浆体在直径为0.0627m和0.0777m的水平管道中流动输送试验研究,通过试验数据分析,给出了浆体从层流到紊流的过渡流速值,结合前人研究成果,给出了浆体过渡流速计算公式。同时通过分析浆体切应力和切变率曲线,发现粉煤灰浆体流型为宾汉体。通过试验数据拟合法,给出了宾汉体屈服应力衰减系数与相对流速偏移量关系的表达式,由此给出了宾汉流体紊流水力坡度计算模型。对比结果表明,模型计算值与实测值最大偏差为9.42%。     

孔眼流入对水平井中流动影响的实验研究

设计并建立了水平井筒变质量流动模拟实验装置。对具有射孔完井的水平井筒变质量流动进行了实验研究,利用先进的数据采集系统获取了大量的实验数据。对水平井井筒单孔眼段流动阻力损失分析可知,流动阻力由三部分组成：管壁摩擦阻力、加速损失和混合损失。对实验数据进行处理得出了混合损失和主流流速与孔眼流速之间的关系。对于一定的主流流速,混合损失随孔眼流速的增大而增大,同时,对于一定的孔眼流速,混合损失随主流流速的增大而增大,此时孔眼的流入对水平井筒中的流动造成的影响比较显著。孔眼的流入增加了井筒中流动的复杂性。对实验数据进行的回归结果表明,在本实验条件和范围内,主流流速和孔眼流速是造成混合损失的主要因素。     

高凝原油的粘弹液环输送

在高粘高凝原油的管道输送中,液环法是一种很有前途的输送方法.它能大幅度地降低原油的流动阻力,其摩阻损失与输送同样流量的水差不多,甚至有可能实现用管道输送接近凝固点的原油.液环输送高粘高凝原油,虽然可以获得显著的减阻效果,但在水平输送过程中,由于水和 ...     

地震波作用下埋地管道截面应力偏移效应研究

PE管广泛应用于城镇燃气、水和浆体等输送领域，地震灾害下埋地管道易发生失效。为此，提出了一种地震波作用下埋地PE管-土耦合数值建模方法，研究PE管力学特性，探究管道内压、地震烈度、围土和覆土厚度等对其力学响应影响规律。结果表明，地震波作用下管道截面应力出现偏移效应，而非0°,90°,180°和270°位置；内压作用下管壁应力增加；管道环向应力随着地震烈度增加而增大，且应力偏移效应更加显著。研究结果可为PE管道敷设和安全评价等提供理论依据。     

岔管群水力特性的试验研究

各种管道工程,诸如有压泄洪洞、水电站压力引水管、复式调压井、分散式船闸输水系统、通风空调设备、煤气及石油的输送系统、核电厂热扩散管道以及城市给排水管道等,都可能出现分岔管,甚至出现分岔管群。在工程设计时,须预知岔管出现后的水头损失、流量分配及流量系数、压强以及流速分布等水力特性。     

Transportation characteristics of gas–solid two-phase flow in a long-distance pipeline

In this study, experiments on fly ash conveying were carried out with a home-made long-distance positive-pressure pneumatic conveying system equipped with a high performance electrical capacitance tomography system to observe the transient characteristics of gas–solid two-phase flow. The experimental results indicated that solids throughput increased with increasing solids–gas ratio when the conveying pipeline was not plugged. Moreover, the optimum operating state was determined for the 1000 m long conveying pipeline with a throttle plate of 26 orifices. At this state the solids throughput was about 12.97 t/h. Additionally, the transportation pattern of fly ash gradually changed from sparse–dense flow to partial and plug flows with increasing conveying distance because of the conveying pressure loss. These experimental results provide important reference data for the development of pneumatic conveying technology.     

除尘管道内铝粉运移及沉积的数值研究

基于DPM(Discrete Phase Model)模型，研究了长直通风管道内粒径服从Rosin-Rammler 分布的铝粉的运移与沉积规律．基于颗粒与壁面的碰撞过程中的能量分析，建立了粉尘沉积-回弹模型，得出了粉尘沉积的判定准则及脱离壁面时的回弹速度．利用UDF 将沉积-回弹模型嵌入Fluent，完成了对管道内粉尘运移和沉积的数值模拟．粉尘沉积的数值结果与实验结果符合得较好，验证了所提模型的有效性．数值结果表明风速的增大使管道内粉尘浓度明显降低，管壁粉尘沉积率也降低；粒径的增大对粉尘浓度的大小影响不明显，主要影响粉尘浓度在管道内的分布情况，同时会增大粉尘在管壁的沉积率．     

Transportation characteristics of gas-solid two-phase flow in a long-distance pipeline

In this study,experiments on fly ash conveying were carried out with a home-made long-distance positive-pressure pneumatic conveying system equipped with a high performance electrical capacitance tomography system to observe the transient characteristics of gas-solid two-phase flow.The experimental results indicated that sol ids throughput increased with increasing solids-gas ratio when the conveying pipeline was not plugged.Moreover,the optimum operating state was determined for the 1000 m long conveying pipeline with a throttle plate of 26 orifices.At this state the solids throughput was about 12.97 t/h.Additionally,the transportation pattern of fly ash gradually changed from sparse-dense flow to partial and plug flows with increasing conveying distance because of the conveying pressure loss.These experimental results provide important reference data for the development of pneumatic conveying technology.     

Wax formation in oil pipelines: A critical review

The gelling of waxy crudes and the deposition of wax on the inner walls of subsea crude oil pipelines present a costly problem in the production and transportation of oil. The timely removal of deposited wax is required to address the reduction in flow rate that it causes, as well as to avoid the eventual loss of a pipeline in the event that it becomes completely clogged. In order to understand this problem and address it, significant research has been done on the mechanisms governing wax deposition in pipelines in order to model the process. Furthermore, methods of inhibiting the formation of wax on pipeline walls and of removing accumulated wax have been studied to find the most efficient and cost-effective means of maintaining pipelines prone to wax deposition. This paper seeks to review the current state of research into these areas, highlighting what is so far understood about the mechanisms guiding this wax deposition, and how this knowledge can be applied to modelling and providing solutions to this problem.     

高饱和黏土中爆炸波作用下直埋聚乙烯管的动力响应

为了解决爆破作业对近距离埋地管道的安全评估问题，对高饱和粘土中爆炸波作用下聚乙烯(polyethylene, PE)管道进行了一系列管道动态响应的原型实验，得到了不同药量下管道动应变、动压力的实验数据和管体及地面的振速数据。实验结果表明:PE管动应变峰值同比例距离具有良好的幂函数衰减关系，在6～11 m/kg1/3比例距离范围内，PE管的环向峰值应变衰减指数（绝对值）比轴向峰值应变衰减指数大；管道动态响应的主振频率略高于土体的主振频率，两者在同一量级，管道合成速度衰减指数大体和管道轴向应变衰减指数相当；压电陶瓷片所测得的电压信号和同测点的应变变化率信号具有较强的相关性。高饱和黏性土由于含水量较高，近距离柔性PE管因受到局部冲击会产生较大的环向应变，管道安全计算时应充分考虑这一因素；随着比例距离的增大，环向应变水平降低，轴向应变水平相对增强；压电陶瓷片因为具有良好可靠的动态性能，作为埋地管道现场监测的技术手段值得采用和推广。     

MPS -DEM 方法数值模拟超长管道固液混输流动

近些年来，深海矿产开发成为热点，其中涉及的固液混输问题逐渐引起学者的关注。如矿粒在海床上的输运，涉及水平管道的输运问题；矿粒从海床输运到海上浮式建筑物，涉及垂直管道的输运问题；矿粒在不同倾角管道内的输运，涉及倾斜管道的输运问题。对于该类问题，由于流体和固体之间的物理差异较大，对于固液两相往往采用不同的数值处理方法。本文使用MPS-DEM耦合方法模拟管道内的固液混输运动。用MPS方法模拟管道内流体的运动，用DEM方法追踪管道内颗粒的运动。在管道的进出口使用周期性边界条件，将多段管道之间进行拼接，从而实现了对超长管道内高雷诺数的颗粒输运现象的模拟。最后，分析管道颗粒和流场的速度及粒子分布等信息，分析流动特征。得到的结果会为超长管道内固液混输现象的研究提供一些借鉴意义及参考价值。     

空中爆炸冲击作用下不同接头形式埋地管线动力响应的对比试验研究

为探明爆炸冲击条件下管线接头部位受力变形的特点和规律,在室内爆炸试验碉堡测试系统内分别对直管线、带直接头和弯头管线动力响应情况进行对比试验研究,测试了接头连接处迎爆面及其背面的轴向应变,并对测试结果进行了对比分析。结果表明,管径突变会产生应力集中,接头部位是管线系统的薄弱环节;接头的厚径比是影响接头部位防爆抗震性能的重要参数;接头的类型是影响管线系统防爆抗震性能的重要因素,在管线设计中要尽量减少弯头数量,设置橡胶软接头可增强管线系统防爆抗震性能。     

A new algorithm of mass flow rate determination in gas production and transportation systems via pressure measurement

The current algorithm for calculating mass flow rate in gas production and transportation systems from outlet pressure measurements is generalized to the case where the inner cross section of the pipe changes with time and is also to be determined in the course of solving the general problem. The generalized algorithm is recommended for identification of gas hydrate formation in the above-mentioned systems. The identification of hydrates in a main gas pipeline in permafrost is considered as an example.     

Experimental and CFD investigation of flow behavior and sand erosion pattern in a horizontal pipe bend under annular flow

The internal erosion of pipelines in oil and gas storage and transportation engineering is highly risky. High gas velocity of annular flow entrained sand will cause damage to the pipelines, and may further result in thinning of the wall. If this damage lasts for a long time, it may cause pipeline leakage and cause huge economic losses and environmental problems. In this research, an experimental device for studying multiphase flow erosion is designed, including an erosion loop and an experimental elbow that can test the erosion rate. The annular flow state and pipe wall erosion morphology can also be tested by the device. The computational fluid dynamics (CFD) method is combined with the experiment to further study the annular flow erosion mechanism in the pipeline. The relationship between gas-liquid-solid distribution and erosion profile was studied. The results show that the most eroded region occurs between 22.5° and 45° in the axial angle direction and between 90° and 135° in the circumferential angle direction of the elbow. The pits and deep scratches form on the surface of the sample after the sand collision.