Fault diagnosis and analysis of main sea water pump based on vibration monitoring in offshore oil field

The main sea water pump is the key equipment for the floating production storage and offloading （FPSO）. Affected by some factors such as hull deformation, sea water corrosion, rigid base and pipeline stress, the vibration value of main sea water pump in the horizontal direction is abnormally high and malfunctions usually happen. Therefore, it is essential to make fault diagnosis of main sea water pump, By conventional off-line monitoring and vibration amplitude spectrum analysis, the fault cycle is found and the alarm value and stop value of equipment are set, which is helpful to equipment maintenance and accident prevention.

Efficacy and safety of active silicone oil removal through a 23-gauge transconjunctival cannula using an external vacuum pump

AIM: To evaluate the efficacy and safety of active removal of silicone oil with low and high viscosity through a 23-gauge transconjunctival cannula using an external vacuum pump.METHODS: This study was conducted as a prospective, interventional case series. A total of 22 eyes of 21 patients [1000 centistokes(c St): 17 eyes, 5700 c St:5 eyes] were included in this study. All patients underwent active silicone oil removal via the entire lumen of a 23-gauge microcannula with suction pressure of a650-700 mm Hg vacuum using an external vacuum pump. A tubing adaptor from the Total Plus Pak誖(Alcon,Fort Worth, USA) was used to join the microcannula and silicone vacuum tube connected to an external vacuum pump. Main outcome measures were mean removal time,changes of intraocular pressure(IOP) and visual acuity,and intraoperative and postoperative complications.RESULTS: Mean removal time(min) was 1.49±0.43 for1000 c St and 7. 12 ± 1. 27 for 5700 c St. The IOP was18.57±7.48 mm Hg at baseline, 11.68 ±4.55 mm Hg at day1 postoperatively(P <0.001), and 15.95±4.92, 16.82±3.81,17.41 ±3.50, and 17.09 ±3.01 mm Hg after one week, one month, three months, and six months, respectively. All patients showed improved or stabilized visual acuity.There was no occurrence of intraoperative or postoperative complications during the follow up period.CONCLUSION: This technique for active removal of silicone oil through a 23-gauge cannula using an external vacuum pump is fast, effective, and safe as well as economical for silicone oil with both low and high viscosity in all eyes with pseudophakia, aphakia, or phakia.

Design and application of electric oil pump in automatic transmission for efficiency improvement and start–stop function

For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.

Research on oil film characteristics of piston pair in swash plate axial piston pump

The research on the oil film characteristic of piston pair is beneficial to the design and optimization of friction pair,which can improve the performance of piston pump.The fluid pressure of piston cavity is accurately obtained by AMEsim simulation.Oil film thickness field model of piston pair under the slanting state of piston is established,and the distribution law is numerically analyzed under different speed and pressure by Matlab.The experiment model pump for oil film characteristic of piston pair is designed to measure oil film thickness under the pressure of 18 MPa.The experiment results show that oil film thickness varies greatly under high pressure,and oil film thickness fluctuates sharply under low speed.The minimum oil film thickness increases with spindle speed increasing and oil film characteristic of piston pair based on the numerical analysis method is verified.This method lays a foundation for studying the friction performance of piston pair in the axial piston pump.

EXPERIMENTAL STUDY ON HIGH-SPEED CHARACTERISTICS OF AUTOMOTIVE ENGINE OIL-PUMP CHAIN

The high-speed multi-cycle impact and speed, load fluctuant characteristics of a kind of narrow-width automotive engine oil-pump chain 06BN-1 are studied through engine assembly and road-drive tests to satisfy the light-weight demand of engine. The worn surface morphologies of rubbing area between pin, bush and roller are also analyzed based on scanning electron microscope. The results show that the main wear mechanism of automotive engine oil-pump chain is fatigue wear, and it＇s failure mechanism is the forming, extending and flaking of cracks on top layer of pin and bush. Pin and bush both occurred cycle-soften phenomenon, and roller occurred cycle-harden. Fretting wear is one of the most important ＂fall to pieces＂ failure causes of automotive chain. Ensuring sufficient strength and plasticity of roller, as well as adopting suitable shaping technology are the effective methods to increase its resistance to multi-cycle impact.

Evaluation of Electrical Submersible Pump on Field Production Network Optimization in Niger Delta Oilfield

Complexity arises when trying to maximize oil productions from fields using Electrical Submersible Pumps (ESP). The complexity increases with the increase in the number of reservoirs and wells in a particular field. Individual well’s ESP frequencies have to be constantly updated to ensure optimum oil productions from the field. The choice of the ESP frequency to be used must come from sound engineering decisions which do not come from mere intuition but must be backed up by mathematical models and computer simulations. This study proposes to evaluate field production network optimization on ESP lifted wells using quadratic sequential programming techniques. The optimization approach seeks to determine the ESP frequency for each well that will lead to the maximum field oil production while honouring the field operational constraints. Two reservoirs and five wells were considered. The non-linear optimization problem for the ESP lifted wells in the field was formulated with their boundary conditions. The simulations were performed in Prosper and GAP software. Prosper software was used in building the individual well’s ESP models for the five wells in the field. Individual well’s model in Prosper was exported to GAP and simulations were run in GAP for the field network system. GAP simulations were run in two cases: case 1 comprises ESP simulation without optimization while case 2 comprises ESP simulation with optimization. For case 1, fixed values of ESP frequency were selected for each well and the GAP software calculates the production rates from the wells in the network accruing from the ESP frequencies inputted. For case 2, there was no input ESP frequency as the GAP software was allowed to calculate based on optimization algorithms, the best suitable ESP frequencies for each well in the field that will lead to the maximum total oil production in the field network while honouring the operational constraint imposed on the systems in the field. From the results, it was realized that at the basis of well, the higher the ESP frequency, the higher the well’s production rates. Sensitivities on the effects of separator pressure on production rates show that separator pressures affect the well’s productions rates. A reduction in separator pressure from 200 psig to 80 psig led to a 1.69% increase in field oil rate. Comparison of results for case 1 and case 2 showed that ESP field network simulation with optimization yields had a higher field production rate than ESP field network simulations without optimization. There was an increase in oil rate of 1.16% and 2.66% for constraints 1 and 2 when ESP simulation was done with optimization rather than without optimization. Also, simulation with optimization comes with higher pump efficiency than simulation without optimization.

An Integrated Oil Production Enhancement Technology Based on Waterflooding Energy Recovery

A new integrated oil production enhancement technology based on water-flooding energy recovery is proposed.After providing an extensive review of the existing scientific and technical literature on this subject,the proposed integrated technology is described together with the related process flow diagram,the criteria used to select a tar-get facility for its implementation and the outcomes of the laboratory studies conducted to analyze emulsion formation and separation kinetics.Moreover,the outcomes of numerical simulations performed using Ansys CFX software are also presented.According to these results,using the proposed approach the incremental oil production may reach 1.2 t/day(with a 13%increase)and more,even at low flow rates(less than 10 t/day),thereby providing evidence for the benefits associated with this integrated technology.

Energy Consumption Analysis and Optimization of Electric Submersible Pump System

Electric submersible pumps account for a considerable proportion in the development of the Bohai Oilfield. Improving the system efficiency of the electric submersible pump wells, ensuring that the units operate in the high-efficiency zone, is essential. Analysis shows that the efficiency of the electric submersible pump system depends on the wear and tear of each component of the submersible pump equipment, the setting of operational parameters, and more importantly, the production status and daily management level of the oil well. Therefore, improving the structural performance of the submersible pump product, optimizing the parameters setting of the oil well, strengthening daily management, establishing a scientific management system, and improving the production management process and system can effectively improve the production efficiency and economic benefits of the oil well, and further achieve the goal of energy saving and emission reduction. In addition, it is necessary to actively promote the concept and technology of energy saving and emission reduction, encourage oilfield enterprises to explore effective measures to reduce the energy consumption of the electric submersible pump system by strengthening the scientific management system, and achieve a green, low-carbon, and high-quality development of oilfield production to achieve the unity of economic benefits, social benefits, and environmental benefits. This article applies the above measures in the P oilfield to achieve energy optimization of submersible electric pump systems, reducing the daily power consumption of single well submersible electric pump systems by 371 kWh per day, increasing the submersible electric pump's lifespan by 200 days, generating considerable project benefits.

基于停泵压降数据的页岩气井单段裂缝参数反演——以长宁N209井区页岩气井为例

水平井多级分段多簇压裂是页岩气藏有效开发的关键技术,准确评价缝网参数是开展压裂效果评估、压裂工艺优化和压后产能预测等工作的重要前提.传统页岩气井压裂裂缝参数表征主要采用裂缝扩展模拟与现场监测等手段,对压裂施工停泵压降曲线的信息挖掘与利用不足.采用数字滤波方法消除停泵压降数据的水锤波动,利用分形裂缝表征页岩气井压裂缝网,结合数值试井分析实现了单段裂缝参数反演,建立了一套基于停泵压降数据的缝网参数反演工作流程.该成果在长宁公司N209井区压裂井成功应用,并对裂缝参数评价结果与一体化压裂模拟和产气剖面测试等反演结果进行了验证.结果表明,基于停泵阶段压降数据的单段裂缝参数反演结果显著提升了参数解释精度,有助于揭示页岩气井段间产气能力差异的原因;气井产能与裂缝总长和裂缝表面积的相关性明显高于利用广域电磁法确定的压裂改造体积,其中,早期日产气量与总缝长相关性最高;预计最终回收率与裂缝表面积相关性最高;缝网总长与单簇压裂液规模强线性相关,反映了长宁区块页岩气井压裂工艺2.0的技术先进性.获取页岩气井单段裂缝参数可为产能主控因素分析和压裂效果评价提供更加有效的分析指标.

螺杆泵转速对油水旋流分离管流场特性的影响

旋流分离器在井下采油螺杆泵作用下会发生复杂的振动现象,对旋流分离器内部流场造成一定影响。为研究螺杆泵不同转速下旋流分离器内部流场的变化规律,以同井注采工艺中螺杆泵作用下的旋流分离管柱为研究对象,针对振动壁面旋流分离管柱结构及工作特点,基于计算流体动力学方法、计算固体力学方法以及流固耦合理论,建立流固耦合力学模型;利用流固耦合分析方法,对双螺杆泵转动条件下井下旋流分离管柱内速度场、油相分布、涡量及湍动能等流场特性进行分析。分析结果表明:随着螺杆泵转速升高,分离器内切向速度和轴向速度强度逐渐减弱,径向速度的不对称性逐渐加剧,转速的周期性变化还会造成径向速度场分布的偏移;螺杆泵不同转速下旋流分离器内部涡量分布不同,随着转速升高,溢流管以及锥段部分附近相关流场的涡旋明显增强;旋流器溢流口附近油相体积分数会随着螺杆泵转速的升高而减小;不同螺杆泵转动状态下,大颗粒油滴的分布不同。所得结果可为螺杆泵井下旋流分离同井注采系统的设计及螺杆泵的转速设定提供参考。

沙粒质量分数对油气混输泵过流部件磨损的影响

为研究沙粒质量分数对油气混输泵过流部件磨损的影响规律,基于DPM模型对油气混输泵内部的沙粒运动进行数值计算,并采用Finnie磨蚀模型计算油气混输泵过流部件的磨蚀率.研究结果表明:在沙粒质量分数较小时,沙粒与流体介质混合均匀;随着沙粒质量分数的增大,增压单元内的沙粒局部质量浓度显著增大,沙粒集中在叶轮压力面及导叶流道中部;沙粒质量分数增大会使磨损区域和磨损率急剧增大;在叶轮域中,磨损首先发生在压力面出口处,吸力面则在进口外缘发生点状和条状磨损;在导叶域中,压力面的磨损主要发生在外缘处,吸力面的磨损主要发生在进口轮毂处;从定量分析看,叶轮叶片表面的磨蚀率普遍大于导叶叶片表面的磨蚀率,磨损最严重的位置为叶轮叶片进口靠近轮毂处.研究结果可为改善油气混输泵抗磨损性能以及提高油气混输泵实际运行寿命提供一定参考依据.

基于GWO-FCM的输油泵故障诊断模型自学习框架

随着输油泵场站无人化建设的发展,企业对输油泵故障诊断技术的要求也越来越高。目前,被广泛使用的利用机器学习算法进行输油泵故障诊断的方法都只能针对模型训练集中已包含的几类故障进行诊断,在企业的实际使用中,仍会出现其他不包含在训练集中的故障而不能被正确自动识别、诊断。针对上述问题,设计了一种输油泵故障诊断模型自学习框架,通过信号处理技术结合深度学习提取深层故障特征,提高工业现场数据的可分性;通过模糊C均值聚类结合相似度度量判别已知故障和未知故障,对出现的未知故障模式进行识别和记录;利用频繁出现的未知故障数据重训练模型,在原有诊断功能的基础上提高对未知故障的识别、诊断及学习能力。为验证方法的有效性,使用工业现场采集的输油泵数据进行实验,结果表明,现有诊断方法所提出的输油泵故障诊断模型自学习框架能够实现对未知故障的准确识别。

航空发动机用滑油泵组碟簧压紧有限元分析

为保证滑油泵组关键部件配流盘与偏心泵体的稳定压紧及泵盖的安全性,依据GB/T 1972—2005标准,选用2只单片碟簧以精准对合方式安装于滑油泵组上.在考虑潜在温度场热变形的影响下,采用热固耦合方法,基于Workbench平台对滑油泵组在不同碟簧初始压缩量(0.6,0.7,0.8,0.9 mm)下进行有限元分析.研究结果表明:当初始压缩量小于0.7 mm时,滑油泵的主要部件受到的压紧力较小,主要受油液周向推力的影响;随着初始压缩量从0.7 mm增至0.9 mm,预压缩端的变形量呈现相应的增长趋势,同时滑油泵体挡板所承受的轴向力也随着初始压缩量的递增而呈现线性增长的规律;在此过程中,配流盘与偏心泵体所受到的轴向推力随着初始压缩量的增大而逐渐增大,确保其能够有效地被压紧且泵盖保持完好无损.研究结果不仅为滑油泵组的初始安装提供了理论依据,而且有助于指导实际工程应用中的安装操作,从而确保滑油泵组的正常运行与使用寿命.

基于运动法的航空发动机高速燃油齿轮泵卸荷槽设计与验证

高压、高速、高温化使得齿轮泵固有困油问题愈发严重,传统卸荷槽结构已难以满足高性能燃油泵设计要求。为此本文提出一种基于运动法的新型卸荷槽结构设计方法,通过构建困油模型并从整泵全局角度分析齿轮参数对困油各项性能的影响规律,以确定齿轮参数并为卸荷槽设计提供约束条件;其次基于齿轮运动规律和卸荷槽设计原则进行了某型燃油齿轮泵卸荷槽的设计,并进行了多个工况下新型卸荷槽和传统卸荷槽困油特性仿真对比;最后试制了样机并通过试验验证了卸荷槽设计的有效性。研究结果表明:所设计的卸荷槽与传统矩形卸荷槽相比,同工况下最大困油压力降低63.4 MPa,流量脉动率减小33.5%,空化区域更小,工作性能更优,能够显著缓解困油带来的不利影响。采用该结构卸荷槽的齿轮泵具有高的容积效率和长时抗汽蚀能力。

汽车油泵盖组合式抽芯机构注射模设计

采用POM材料对某燃油泵盖塑件进行注射成型。模具设计的难点为模腔充填困难、成型精度和尺寸稳定性要求高、难以脱模等。因此,采用1模1腔布局,保证尺寸精度达到MT3级,并且,精度稳定性较好;还需要开设直接浇口,模腔得到充分充填;主要成型件及滑块均设置Φ8mm的水路,模腔得到均衡冷却,保证尺寸精度的稳定性;除此以外,设计了8个滑块抽芯机构,用于局部复杂特征的脱模。机构中设计了一种二次抽芯滑块复合机构和一种复合式顺序抽芯滑块机构。二次抽芯滑块复合机构中,先由斜导柱驱动第一次抽芯滑块抽芯,再由油缸驱动完成第二次抽芯滑块的抽芯和2个复合滑块的移位,解决了外壁上交叉特征的脱模难题。复合式顺序抽芯滑块机构中,先由油缸驱动第一次抽芯滑块完成抽芯,同时解除第二次抽芯滑块的限位,然后,第二次抽芯滑块再完成抽芯,解决了塑件中交叉内孔的脱模难题。

基于AMESim的新型变排量机油泵建模与仿真研究

以一种新型叶片柱塞复合形式的二级变量叶片泵为研究对象,其主要特点是将叶片顶端嵌入到定子中,转子、叶片、定子同时转动,减小了高速时的叶片冲击。推导叶片柱塞复合作用下泵的瞬时流量特性公式。基于AMESim仿真平台搭建比例电磁阀、瞬时流量、变量机构模型,并对二级变量叶片泵特性进行仿真,并通过台架试验进行相关验证。实验结果表明:该泵在中低速下压力-流量曲线吻合较好,说明流量和变排量建模准确;加减速曲线说明泵在比例阀不同占空比时,压力调节具有稳定性。

泵/马达困油现象充分缓解的等排量大模数方法

为了充分缓解外啮合齿轮泵/马达困油现象,在确保产品输出能力不变的等排量前提下,分析模数对困油腔内的负荷流量、泄漏流量和卸荷流量的影响,提出了一种等排量大模数的设计方法,并基于这3种流量的瞬时平衡和同齿形参数、不同模数下卸荷面积的演绎计算,计算出困油压力并由此判断出困油现象的缓解程度。结果表明,对于给定的齿轮副和工况条件,等排量下的齿宽系数反比例于模数的3次方,模数越大,困油现象越趋于缓解,且径向力越小,但齿宽系数越小;同齿形参数、不同模数下的卸荷面积等于模数的平方乘基准模数为1下的卸荷面积,从而为同齿形参数、不同模数下的卸荷面积计算,提供了极大方便;卸荷槽外通的进出口压力互为颠倒,导致泵较马达的困油现象更严重,但等排量小模数马达同样也会出现较为严重的困油现象。得出了选择最大化/较大的模数应为泵/马达的设计准则的重要结论。

基于NSGA-Ⅱ的滑油泵叶轮结构优化设计

滑油泵常需要在高空、低压工况下稳定运转,常会出现供油不足、效率降低等问题。为了得到满足设计要求且具有最佳性能的滑油泵,以某直升机用滑油泵叶轮为研究对象,对其结构进行优化设计。选择高空两个典型工况的效率与扬程作为优化目标,利用NSGA-Ⅱ算法对滑油泵叶轮几何参数进行寻优,对优化前后的滑油泵效率、扬程进行对比分析。采用CFD流体仿真及实验方法对优化结果进行对比验证。结果表明:所选优化参数对滑油泵性能有较大影响,优化后的滑油泵叶片位置附近流动更加平稳,高低压区域过渡平缓,能量损失更小,且降低了汽蚀发生的可能性;优化后的滑油泵设计点扬程提高2.6 m,效率提高2.86%。

双端面机械密封在双螺杆原油泵上的应用

基于原油库拆建工程项目,对双螺杆原油泵原采用的单端面金属波纹管机械密封改造为新型的带泵效环的背靠背双端面机械密封,并配套冷却循环辅助系统,经现场工业考核,背靠背双端面机械密封在双螺杆原油泵上得到良好应用。结果表明,新改造的双端面机械密封彻底解决了原密封存在的摩擦副磨损严重、泄漏量大、使用寿命短等问题,实现了工艺介质的零泄漏并确保设备长周期安全稳定运行。