The Measurement of Oil,Gas and Water Flowrates in Three-Phase Slug Flow

Three-sphase flow invo1ving oil-water two immiscible liquids and gas which is often foundin the fields of petroleum production has been studied in this paper.A new method with thecombination of a horizontal tube,a downward flow vertica1 tube and an orifice to measure theflowrates is presented.In this method the frictional pressure drop in the downward vertical tube isreplaced by that in the horizontal tube,the void fraction is derived from the gravitational pressuredrop,then the volume fraction of the individual phase can also be obtained.The individual flowratescan be calculated when the water fraction is known.This method is applicable for many kinds ofoil-wells to measure the flowrates of crude oil,natural gas and water.Compared with other methods,the presented method involves fewer measuring parameters.The experimental results proved quitegood accuracy of the method,with measurement deviation within 10%,and reliable results wereobtained under high Dressure conditions.

Test Rig Effect on Performance Measurement for Low Loaded Large-Diameter Fan for Automotive Application

Large diameter fans with low solidity are widely used in automotive application for engine cooling. Their designs with small chord length help reducing the torque on the electrical motor and providing a good aerodynamic compromise between several operating conditions, some of these being at high flow rate. Their global performances are measured according to the ISO standard DP 5801, which allows comparison of results from different facilities. However, some variations in global performances are observed when considering results from two different test rigs. On a fan selected for the purpose of this study, up to 6 % of efficiency is lost on the worst case. As efficiency is more than ever a key factor to select a component, some experimental and numerical investigations were conducted to analyze the fan behavior on each facility. Two sets of measurement and simulation are performed and compared. Geometries considered for the domain of computation include the test rig plenum, the torquemeter, the ground and a large domain for the atmospheric conditions. The exact fan geometry with tip clearance and under-hub ribs is also considered. Numerical results show a good agreement with experiment in both cases when convergence is reached and for low flow rate when computations are switched to unsteady mode. Comparisons show that simulations are able to capture the different fan behaviors depending on the confguration and those efficiency losses previously observed are correctly predicted. These results are further analyzed to perform some post-processing. Blade loading remains identical for both cases but disparities appear in the wake and its interaction with the surrounding. Tiny details that are often neglected during experiment and/or simulation appear to be the cause of slight variations. Position of the torquemeter and shape of the plenum are among the parameters that various and that have cumulative effects. Efficiency being a ration of pressure and torque, variations are rather important. Finally, these results are discussed in terms of rules for conception and a new geometry less sensible to loss of efficiency is proposed.

液体微小流量测量技术研究进展

随着流体力学与生命科学、材料科学、医疗健康、能源环境和先进制造等多学科领域的交叉融合,微量液体与微流控技术逐渐在这些领域取得了广泛的应用.与此同时,液体微小流量(每分钟几微升、几纳升,甚至更低)的测量需求逐渐凸显出来.随着特征尺度的减小,原有的液体流量测量技术已经无法满足测量准确度的要求,因此,需要流量测量技术的进一步发展来满足微小流量测量和传感器微尺度集成的需求.文章介绍了液体微小流量的应用背景和面临的主要问题,首先,根据测量过程中是否引入外界能量(例如电能、热能等),将现有的和正在开发的液体微小流量测量技术分为有源流量测量技术和无源流量测量技术;其次,分别对其包含的具体测量技术展开论述,主要包括质量流量测量技术(科里奥利和微谐振器)、热式流量测量技术(热损失型、热分布型和热脉冲型)、光流控流量测量技术(光致褪色)、压力转换流量测量技术(压差式、悬臂式和柔性膜形变)、粒子测速技术、重力测量技术和弯月面追踪技术等,并讨论了上述测量技术的传感测量原理、测量性能指标和优缺点;最后,结合液体微小流量测量技术的发展和先进测量体系的建设,总结了液体微小流量测量的应用前景和有待解决的挑战.

S型皮托管对向和非对向测量方法准确度实验研究

S型皮托管的对向和非对向测量方法准确度在不同工况下有较大差异。通过风洞实流实验对风速、流速攻角和结构参数对S型皮托管对向和非对向测量方法准确度的影响进行了研究。结果表明:风速由5 m/s变化至30 m/s时,在不同流速攻角下S型皮托管对向和非对向测量准确度最大差异超过10%;对向和非对向测量中静压孔的压力变化是皮托管在较大流速攻角下造成测量误差的主因;外径较小、总静压孔距较大、测量端弯曲角度在15°至30°间、取压孔内径更小的S型皮托管在对向和非对向测量中都有更高的测量准确度;俯仰角取正值时对向测量准确度全面优于非对向测量,在俯仰角和偏航角同为45°时测量准确度差异达到最大值,大于70%。

崩岗侵蚀对洪积扇农田质量的影响和防治措施

崩岗是南方红壤丘陵区严重的土壤侵蚀地貌,崩岗侵蚀会对洪积扇农田质量造成严重危害,但目前有关文献报道较少。崩岗侵蚀产生的大量洪积物冲入农田后,会破坏水利设施、沙化土壤、恶化农田生态环境。本文从土壤质量、作物产量、环境影响3个方面阐述崩岗侵蚀对洪积扇农田的危害,提出相应的防治措施:工程措施为截流拦沙,林草措施为构建生物保护屏障,农业措施包括改良土壤质地、提高土壤肥力。合理搭配使用上述措施可以改善洪积扇农田,减少崩岗侵蚀危害,提高土地生产力。开展崩岗洪积扇土壤退化成因及防治措施的研究,可为崩岗洪积扇区农田质量恢复提供科学的理论依据。

配水器扇形水嘴及其通信模块设计与仿真

分层注水是一种有效提高原油采收率并维持油田长期稳产的注水技术。在油田开采过程中,地层压力随开采程度的增加而降低,为保持油田的长期稳产,可向油田进行分层注水,测控一体化井下配水器是实现分层注水的关键组成部分,但其中测调精度不稳定。为此,在水嘴结构方面创新设计了一种适用于产生压力和流量脉冲波的扇形水嘴。由此产生的流量波和压力波信号具有形状规则、波形精度高的优点,从而提高了信号传输的成功率和有效性。为实现对井下压力和流量信号的实时监测,该配水器集成了压力波监测模块、内外压监测模块以及流量计模块,为不同油层的注水量智能调节提供了可靠的数据支持。对所设计的配水嘴和地面控制器进行内部流体仿真,相同条件下,45°和90°配水嘴转角时流场的最大压差为3 320 Pa,结果表明配水嘴开度越大,流场压差越小,符合节流压降规律,相同条件下,0°、45°和90°地面控制器转角时流场的最大压差为48 690 Pa,井口阀开度不同其内部流场状态有变化,井口阀开度越大,流场压差越小,经过实验验证,该设计可以相对于其他装置有效提高注水精度,可被应用于大型油田。

火电厂锅炉引风机故障原因分析及其维修对策研究

在火电厂锅炉引风机为重要辅助设备,引风机的安全稳定运行直接影响到锅炉的运行问题。基于此,以山西阳泉某火电厂锅炉HA46036-8Z型静叶可调轴流式引风机为研究对象,对该引风机常发生的故障类型及原因进行分析,针对性提出了维修对策,有效提高了该火电厂锅炉引风机维修水平,安全经济效益显著。

电厂一次风机失速原因及预防研究

随着电力行业的快速发展,电厂一次风机在发电过程中的重要性日益凸显。一次风机是确保锅炉燃烧稳定和电厂安全运行的关键因素,然而其实际运行中常常出现失速问题,从而影响电厂的日常发电工作。基于此,对预防电厂一次风机失速的重要性进行分析,并探讨导致风机失速的具体原因,进而探究有效的预防措施,旨在降低电厂一次风机失速的风险,提高电厂的运行效率和安全性。

河北某风电场机组低温适应性技改分析

随着风电行业的逐渐成熟,风机技改成为提高设备可利用率的主要方式。通过分析低温气候环境对风电机组的实际运行情况的影响,提出针对低温气候环境的风电机组运行的防护及技改措施,以达到提升风机适应性和设备可利用率的目的。

电机控制系统对电控硅油离合器风扇的影响因素及可靠性分析

分析了电控硅油离合器风扇对比其他离合器风扇的优势,阐述了电控硅油离合器风扇的产品特点和工作原理,通过分析电机控制系统对电控硅油离合器风扇试验的影响,并进行了可靠性测试。结果表明,电控硅油离合器风扇可以满足对离合器风扇的性能要求。

超长距离掘进巷道通风安全保障技术研究

为了确保超长距离巷道掘进通风系统平稳运行,以31采区支架专用运输巷掘进通风为例,通过计算工作面用风量并考虑长距离通风时风筒漏风情况,综合选择了大功率局部风机,实施了变频通风和柔性风筒将阻措施,并制定了长距离通风安全保障措施。实践表明,31采区支架专用运输巷掘进工作面通风稳定,供风量在592 m~3/min左右,风速在0.33 m/s左右,风量和风速始终在合理范围内,充分保障了工作面良好的工作环境。

基于图像识别的湿度检测

依据河北省自然科学基金“氮化碳的结构演变过程对其化学发光检测性能影响机制研究”和发明专利“湿度的检测方法及装置”的研发内容,结合颜色对湿度的水致变性,融合感光元件检测色彩信号电荷量的解算,论述了基于被测物体的图像色彩识别的湿度检测方法和测试装置的具体结构型式,为固体物体的湿度检测提供了新的解决途径。

Flowrate Measurement in Turbulent Liquid Metal Channel Flow Using Time-of-Flight Lorentz Force Velocimetry:Experimental Investigations and Numerical Modeling

Lorentz force velocimetry(LFV)is a suitable non-contact technique to measure flow velocity and flowrates in electrically conducting high-temperature melts.LFV is based on the principles of magnetohydrodynamics:when an electrically conducting fluid passes the field lines produced by a magnet system,eddy currents are induced within the fluid.The interactions of the eddy currents with the magnetic field generate Lorentz forces.Using LFV the counterforce acting on the magnet system is measured.Such a flowmeter consists of a permanent magnet system and an attached digital force sensor.The force recorded by the flowmeter is proportional to the flowrate Q and depends on both the electrical conductivity σ of the fluid and the spatial distribution of the applied magnet field B.However,in metallurgical applications,σ is often unknown or fluctuates in time as it strongly depends on both temperature and composition of the melt.In the present paper we investigate a technique called Time-of-Flight Lorentz force velocimetry ToF LFV.In this technique,the flowrate can be determined by just cross-correlating the two force signals recorded by two flowmeters which are arranged one behind the other separated by a certain distance D.Sensing the passage of the triggered vortices, this ToF LFV measures the transit time τ of these vortices.Then we recalculate the velocity V according to the relation V = D/τ.We experimentally and numerically study turbulent liquid metal flow in the test facility EFCO(electromagnetic flow control channel)using the eutectic alloy GainSn as a test fluid.Our experiments show that this electromagnetic ToF LFV is well suited to determine the flow velocity and flowrate.The experiments are accompanied by numerical simulations using the commercial program package FLUENT.

Non-intrusive flowrate measurement and monitoring system of plant-protection unmanned aircraft systems based on pump voice analysis

Application of Unmanned Aircraft Systems(UAS)for plant protection is becoming a common tool in agricultural field management.To avoid shortcomings of intrusive flowrate sensors including poor measurement accuracy and poor anti-vibration ability,a non-intrusive flowrate measurement and monitoring system of plant-protection UAS was developed based on pump voice signal analysis.It is mainly composed of STM32 processor,microphone and signal-conditioning circuit.By collecting and analyzing the voice signal of the pump in the UAS,the monitoring system will output the real-time values of spraying flowrate and amount.An extraction model was developed to determine operation status and primary frequency of the pump based on voice signal analysis.Real-time spray flowrate can be determined from the real-time extracted primary frequency and the fitted correlation formulas of spraying flowrate under outlet area and pump primary frequency.The flowrate correlation equation of one certain pump from 4-rotor UAS 3WQFTX-1011S was obtained,the max deviation rate of fitted spray flowrate was only 2.8%.In primary frequency extraction test,the error rate of primary frequency extraction was less than 1%.In the 4-rotor UAS flight tests:the max deviation of operating starting/end point was only 0.7 s and the max deviation of extracted total operating time was only 0.8 s;the deviation of extracted spray flowrate was less than 2%,and the max deviation rate of total spray amount was 3.2%.This research could be used as a guidance for plant-protection UAS non-intrusive flowrate measurement and monitoring.

Correlation between Aerodynamic Noise and Velocity Fluctuation of Tip Leakage Flow of Axial Flow Fan

In the present paper the attention is focused on correlation between fan noise and velocity fluctuations of tip leakage vortex around rotor blade of a low pressure axial flow fan at the maximum pressure operating point. We measured time fluctuating velocity near the rotor tip around the rotor blades by using a hot-wire sensor from a relative flame of refer- ence fixed to the rotor blades. As the results, it is clear that the velocity fluctuation due to tip leakage vortex has weak periodicity and the hump portion appeared in its spectrum. If the flow rate was lower than the design condition, the tip leakage flow became to attach to the following blade and the sound pressure level at frequency of velocity fluctuation of this flow was increased. The correlation measurements between the velocity fluctuation of tip leakage flow and the aerodynamic noise were made using a rotating hot-wire sensor near the rotor tip in the rotating frame. The correlation between the velocity fluctuation due to tip leakage flow and acoustic pressure were increased due to generation of weak acoustic resonance at the maximum pressure operating point.

航空发动机碳纤维复合材料风扇叶片叶尖间隙测量研究

动叶片的叶尖间隙参数直接决定航空发动机的工作效率和运行安全,随着发动机朝着质量更轻、运转效率更高的方向发展,碳纤维复合材料(CFRP)被广泛应用于大涵道比航空发动机风扇叶片的设计,然而材料导电性会影响间隙测量结果。提出了一种基于电容法的CFRP叶片叶尖间隙测量方法;利用显微观察和元素分析,获取了CFRP叶片导电性规律,建立了仅碳纤维层参与构成电容器极板的叶尖间隙测量模型;开展了金属叶片和CFRP叶片叶尖间隙测量的仿真和实验,结果表明,两种叶片在不同间隙值下的电容输出呈比例关系,CFRP叶片的叶尖间隙测量精度优于45μm;完成了某型大涵道比航空发动机的测量试验,验证了航空发动机CFRP风扇叶片叶尖间隙测量方法的可行性和可靠性。

INFLUENCE OF CAPILLARITY ON NANO-LITER FLOWRATE MEASUREMET WITH DISPLACEMET METHOD

Nanoqiter flowrate measurements in micro-tubes with displacement method were performed and the effect of capillarity force on the accuracy was investigated through lab experiments and theoretical analysis in this article. The experiments were conducted under the pressure drops ranging from 1 kPa to 10 kPa in a circular pipe with a diameter of 50 pm, to give the pressure-flowrate （P-Q） relation and verify the applicability of the classical Hagen-Poiseuille （HP） formula. The experimental results showed that there existed a discrepancy between the experimental data and the theoretical values predicted by the HP formula if the capillary effect was not considered, which exceeded obviously the limit of the system error. And hence a modified formula for the relation, taking the capillary effect into account, was presented through theoretical deduction, and after the HP formula had been modified the error was proved to be less than 3%, which was permitted in comparison with the system error. It was also concluded that only by eliminating the effect of the capillary force in experiments could the original HP formula be employed to predict the pressure-flowrate relation in the Hagen-Poiseuille flow in the micro-tube.

超级高铁安全评判的解释结构模型

为探究超级高铁初期的安全性,提出一种基于概念扇的超级高铁安全性解释结构模型。首先,利用概念扇对超级高铁的5类安全问题进行初步分析,得到18种潜在风险要素;其次,采用解释结构模型进一步分析风险要素间的相互关系并划分层级,建立超级高铁安全模型,找出影响超级高铁安全运行的深层次、间接和直接风险要素;最后,根据超级高铁安全模型,提出相应的风险管控措施。结果表明,主观原因是影响超级高铁安全运行的最深层风险要素;检测系统故障、管道损坏和端口对接密封性差是影响超级高铁安全运行的间接风险要素;抽气系统故障、过渡舱损坏和未检测到列车驶入是影响超级高铁安全运行的最直接风险要素。

板坯连铸机扇形段基础框架测量安装技术实践

板坯连铸机扇形段基础框架安装精度是连铸机主机设备安装整体尺寸闭环中的重要一环,是整个连铸机寿命周期中直接影响对弧精度,进而影响产品质量的关键参数。为了快速精确测量并调整基础框架精度,对某两台双流板坯连铸机采用绘图法和解析法两种测量安装技术。该测量过程利用基础框架设备上测量销位置,初步调整各框架定位销精度到1 mm以内,随后通过全站仪-棱镜采集安装底面和导向板上的有效数据。绘图测量法是在理想坐标系中将实际采集的数据进行数据分析对比,解析法是通过辊列原始坐标等原始设计数据进行推导计算得出需要精调的数据信息,调整设备到设计允许误差范围内。该技术保证各框架调整精度±0.1 mm,满足板坯连铸机的生产要求,对扇形段基础框架精准测量安装具有重要指导意义。

风机实时监测和失速预警系统开发及应用研究

电站轴流风机的运行状态对烟风系统阻力的变化非常敏感。当烟道阻力增大时,轴流风机易发生抢风失速现象,进而影响电站锅炉机组的安全运行。为准确获取轴流风机的实时运行状态,采用三种测量方法相互协调的方式提高了流量测量准确性,并通过设定不同失速安全阈值确定了风机运行状态的分级预警区。在此基础上,基于C语言开发了轴流风机实时监测和失速预警系统。以浙江某发电机组引风机为例,对该系统进行了现场应用。应用结果表明:该系统可准确评判风机当前的运行状态。当风机运行工况点靠近失速线时,系统可准确发出不同等级的预警信号,提醒运行人员及时调整风机运行状态,保证了风机运行的安全性和可靠性。