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.

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.

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.

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.

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%。

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。

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。

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.

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。

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.

海上油气田机泵机械密封泄漏信号检测方法设计

为避免出现大型海上油气田开采事故,保证机泵机械密封装置正常运行,提出针对海上油气田机泵机械密封的泄漏信号检测方法。利用小波包分解细化海上油气田机泵机械密封振动信号高频部分,运用希尔伯特变换重构信号,归一化处理信号矢量提取机械装置异常信号,使用匹配追踪法去除信号噪声。计算油体流动规律,通过音波评估信号波动范围,以温度与压力为前提,将高斯函数作为分类核函数,采用支持向量机构建泄漏信号检测判断函数,完成机械密封泄漏信号检测。实验结果表明:所提方法信号降噪能力较强,在保证机械密封泄漏检测准确性的同时,检测耗时最短,有效提高了海上油气田开采效率,可带来可观的经济收益。

原油管道顺序输送节能运行优化技术研究

为实现输油计划一定前提下原油管道顺序输送的运行优化,在离散时间表达式的基础上,建立了沿程外输泵电费和加热炉燃料费最低的目标函数,考虑不同时间步下的泵站特性约束、管道压力约束、流量约束和温度约束等,对于重要节点的时间步采用动态规划算法求解,对于其余常规时间步采用自适应遗传算法求解,结合实例进行算法验证和分析。结果表明,优化后,各站在不同时间步的开泵数量均降低,且有备用;部分站在部分时间步可以停运加热炉,实现热力越站;与原运行方案相比,月节约耗电量439.2×10^(4)kWh,月节约耗油量1605.6 t,月节约运行费用871.2万元,求解时间仅为0.21 h,满足计算精度和计算效率的要求。

某商用车怠速油底壳异响问题分析

针对产品开发过程中某柴油车型发动机油底壳怠速时“呜呜”异响问题,通过噪声与振动的测试及仿真分析,对油底壳异响原因进行分析。结果表明,怠速时机油泵的工作激励频率与油底壳模态频率耦合,形成“呜呜”声,并通过油底壳表面辐射出来。进一步实验研究表明,随着机油温度的升高,机油泵功率、工作激励幅值会逐步减小,异响逐步减小。同时实验研究表明,机油量对油底壳模态频率有影响,油底壳内机油加注量越多,油底壳模态频率越低,油底壳表面振动幅值及异响均逐步减小。针对该异响问题,明确该发动机机油加注上限及下限时油底壳对应频率范围后,通过优化怠速转速,提高油底壳模态频率等使机油泵激励频率与油底壳模态频率避频,解决了该异响问题。

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。

汽车机油泵体压铸工艺数值模拟与优化

为满足汽车铝合金机油泵体压铸件高气密性和高强度的要求,解决该铸件缩松、缩孔缺陷问题,进行压铸工艺设计和优化。首先对铸件进行工艺分析,根据经验分别设计浇注排溢系统并初步选取工艺参数;再运用田口正交试验法设计了5因素4水平压铸工艺参数方案,并使用Procast进行数值模拟。将16组正交试验结果基于信噪比进行极差和方差分析,结果表明,模具温度对缩松缩孔的影响最为显著,5因素的最优工艺参数为:浇注温度650℃、模具温度240℃、慢/快压射距离200 mm/60 mm、快压射速度为3.0 m/s、慢压射速度为0.2 m/s。数值模拟结果显示,该工艺参数组合下铸件缩松、缩孔体积为1.067 cm^(3),较优化前降低了26.5%。试模结果表明,铸件外观完好,关键部位X射线探伤显示无明显缩孔;采用金相显微镜(OM)和扫描电镜(SEM)对铸件进行组织观察,发现铸件各区域组织致密;力学性能测试表明,压铸件显微硬度大于HV85,同等工艺下试棒平均拉伸强度为253.36 MPa,铸件满足使用要求。

某V型发动机凸轮轴扭振突变原因分析与改进

针对某V型发动机在油泵速比4:3情况下运行过程中传动链条断裂的问题,开展发动机转速波动与扭振测试,发现右侧凸轮轴在发动机全负荷加速进程中存在转速突增和4阶扭振突变现象,怀疑传动链条断裂与右侧凸轮轴扭振突增有关。为解决右侧凸轮轴扭振突增的问题,更改油泵速比为10:9,再次开展测试进行对比分析,结果表明:油泵驱动齿轮与右侧排气凸轮轴转速波动与扭振具有一定相似性,油泵速比改变后,转速波动与扭振均未发生突变现象,右侧排气凸轮轴转速波动率由52.6%降至20.7%,凸轮轴扭振在3.3阶处达到最大值,最大扭振角由1.57度降至0.506度,转速波动与扭振得到明显改善,提供了一种右侧凸轮轴转速波动与扭振突增问题的解决方案。

分采泵迷宫密封泄漏率的动网格技术分析

分层采油泵作为油田开采中、后期常用设备,其柱塞与泵筒间的密封常采用迷宫密封,由于井下高温高压的工作环境,密封间隙漏失成为影响泵效的主要问题。为探究压差流和剪切流对密封泄漏率的影响,基于计算流体动力学和Fluent动网格技术对密封间隙流场进行仿真实验,利用动网格中网格弹性光顺和网格重构的方法,避免了由运动壁面引起的网格畸变,进一步揭示间隙流场的特性。研究结果表明:在瞬态仿真中由运动壁面引起的剪切流作用更加明显,剪切流速的增大使边界层厚度变薄,进而影响泄漏率;间隙宽度、两端压差和柱塞运动速度对泄漏率均呈现正相关的关系;泄漏率主要受间隙宽度和压差流的影响,受剪切流影响较小。