Trend Prediction Method Based on the Largest Lyapunov Exponent for Large Rotating Machine Equipments

In order to predict electromechanical equipments＇ nonlinear and non-stationary condition effectively, max Lyapunov exponent is introduced to the fault trend prediction of large rotating mechanical equipments based on chaos theory. The predict method of chaos time series and two methods of proposing f and F are dis- cussed. The arithmetic of max prediction time of chaos time series is provided. Aiming at the key part of large rotating mechanical equipments-bearing, used this prediction method the simulation experiment is carried out. The result shows that this method has excellent performance for condition trend prediction.

Opening and Sharing of Large-scale Instruments and Equipment in Agricultural Research Institutes:A Case Study of Environment and Plant Protection Institute of Chinese Academy of Tropical Agricultural Sciences

The article introduces the main practices and achievements of the Environment and Plant Protection Institute of Chinese Academy of Tropical Agricultural Sciences in promoting the sharing of large-scale instruments and equipment in recent years,analyzes the existing problems in the management system,management team,assessment incentives and maintenance guarantee,and proposes improvement measures and suggestions from aspects of improving the sharing management system,strengthening management team building,strengthening sharing assessment and incentives,improving maintenance capabilities and expanding external publicity,to further improve the sharing management of large-scale instruments and equipment.

Research of Personnel Operational Ability Evaluation of Large-scale Complex Equipment

The level of personnel operation ability determines the expected effectiveness of large-scale complex equipment. Firstly, this paper constructs the personnel operational ability evaluation index system and analyzes the data source of index. Secondly, the weight of index is determined and the fuzzy comprehensive evaluation model is proposed. Finally, results of instance analysis show that the evaluation model is feasible and effective.

Novel Method for Spatial Angle Measurement Based on Rotating Planar Laser Beams

Spatial angle measurement, especially the measurement of horizontal and vertical angle, is a basic method used for industrial large-scale coordinate measurement. As main equipments in use, both theodolites and laser trackers can provide very high accuracy for spatial angle measurement. However, their industrial applications are limited by low level of automation and poor parallelism. For the purpose of improving measurement efficiency, a lot of studies have been conducted and several alternative methods have been proposed. Unfortunately, all these means are either low precision or too expensive. In this paper, a novel method of spatial angle measurement based on two rotating planar laser beams is proposed and demonstrated. Photoelectric receivers placed on measured points are used to receive the rotating planner laser signals transmitted by laser transmitters. The scanning time intervals of laser planes were measured, and then measured point＇s horizontal/vertical angles can be calculated. Laser plane＇s angle parameters are utilized to establish the abstract geometric model of transmitter. Calculating formulas of receiver＇s horizontal/vertical angles have been derived. Measurement equations＇ solvability conditions and judgment method of imaginary solutions are also presented after analyzing. Proposed method for spatial angle measurement is experimentally verified through a platform consisting of one laser transmitter and one optical receiver. The transmitters used in new method are only responsible for providing rotating light plane signals carrying angle information. Receivers automatically measure scanning time of laser planes and upload data to the workstation to calculate horizontal angle and vertical angle. Simultaneous measurement of multiple receivers can be realized since there is no human intervention in measurement process .Spatial angle measurement result indicates that the repeatable accuracy of new method is better than 10＂. Proposed method can improve measurement＇s automation degree and speed while ensuring measurement accuracy.

Numerical simulation and experimental study of the characteristics of packing feature size on liquid flow in a rotating packed bed

Rotating packed bed has high efficiency of gas-liquid mass transfer.So it is significant to investigate fluid motion in rotating packed bed.Numerical simulations of the effects of packing feature size on liquid flow characteristics in a rotating packed bed are reported in this paper.The particle image velocimetry is compared with the numerical simulations to validate the turbulent model.Results show that the liquid exists in the packing zone in the form of droplet and liquid line,and the cavity is droplet.When the radial thickness of the packing is less than 0.101 m,liquid line and droplets appear in the cavity.When rotational speed and radial thickness of the packing increase,the average diameter of the droplets becomes smaller,and the droplet size distribution becomes uniform.As the initial velocity of the liquid increases,the average droplet diameter increases and the uniformity of particle size distribution become worse.The droplet velocity increases with the radial thickness of the packing increasing,and gradually decreases when it reaches the cavity region.The effect of packing thickness is most substantial through linear fitting.The predicted and simulated values are within±15%.The cumulative volume distribution curves of the experimental and simulated droplets are consistent with the R-R distribution.

Experimental study of rotating wind turbine breakdown characteristics in large scale air gaps

When a wind turbine is struck by lightning,its blades are usually rotating.The effect of blade rotation on a turbine＇s ability to trigger a lightning strike is unclear.Therefore,an arching electrode was used in a wind turbine lightning discharge test to investigate the difference in lightning triggering ability when blades are rotating and stationary.A negative polarity switching waveform of 250/2500 μs was applied to the arching electrode and the up-and-down method was used to calculate the 50%discharge voltage.Lightning discharge tests of a 1：30 scale wind turbine model with 2,4,and 6 m air gaps were performed and the discharge process was observed.The experimental results demonstrated that when a 2 m air gap was used,the breakdown voltage increased as the blade speed was increased,but when the gap length was 4 m or longer,the trend was reversed and the breakdown voltage decreased.The analysis revealed that the rotation of the blades changes the charge distribution in the blade-tip region,promotes upward leader development on the blade tip,and decreases the breakdown voltage.Thus,the blade rotation of a wind turbine increases its ability to trigger lightning strikes.

Scaling of motion and governing equations for baroclinic large-scale motions in equatorial ocean

An obvious characteristic of the baroclinic large-scale motions in the equatorial ocean is that the meridional scale H of motion is far smaller than the zonal scale L. The scaling of motion carefully with this striking characteristic in this paper results in two conclusions, i. e., the Coriolis terms associated with the horizontal component of the rotation vector cannot be neglected in the governing equations; and the use of the absence of heating is not suitable to the equatorial region. In this paper the equatorial β-plane nondimensional governing equations with the small parametersδ_0 andδ_1 have been Obtained.

基于粒子群算法的同步定相振动控制仿真研究

传统的同步定相技术采用螺旋桨特征理论,通过遍历各个相位差的组合来寻找最优相位差,但随着设备数目增多,其计算量大大增加,不利于工程应用。利用遗传算法可计算设备间的最优相位差,但其计算复杂且收敛速度较慢,而安装过多传感器作为振动评价点来衡量系统整体振动水平则会导致数据冗余并增加系统复杂度。为了提高计算效率和精度,提出一种基于粒子群算法(PSO)的同步定相振动控制方法,通过粒子群算法对振动评价传感器在数量约束条件下进行布放位置优化,建立振源设备和振动评价点之间的数学模型,并再次使用粒子群算法更新粒子的位置和速度,实现参数空间中的最优相位求解。根据计算结果调整激励力间的相位差,实现同步定相振动控制。仿真结果表明,采用粒子群算法能使传感器数量大大减少,使用计算得到的最优相位调整旋转机械设备激励力间的相位差,能有效减小振动向船体结构的传递。与遗传算法相比,粒子群算法在计算效率和收敛速度方面表现出更好的性能。

基于奇异值滤波的旋转装备转速提取

课题组针对无硬件测量设备的振动信号转速信息提取算法中存在频带不易确定和运算量大等问题,提出一种奇异值分解滤波的转速估计方法。先将振动加速度信号先作Hankel重构,再奇异值分解,然后利用差分奇异谱确定重构奇异分量,依据连续两个奇异分量确定一个频率成分,重构各频率分量信号,最后对重构分量作频谱分析估计当前转速。实验表明:奇异值分解滤波能有效提取信号中的频率分量,进而从振动加速度信号中提取转速信息。对比实验证明了课题组提出的方法具有频带自适应、易于实现和精度高的优势。

基于Python的振动监测与故障诊断系统开发

风机、泵和离心机等旋转设备是广泛应用于工业生产和日常生活的重要设备。在“服务型制造”的转变推动下,智能化、自动化以及数字化是这些设备的发展趋势,也是提高设备安全性、可靠性的重要方式。通过现场检测端和远程Web端的软、硬件设计,结合经典故障诊断算法与利用大数据的人工智能诊断方法,开发了低成本、高开放性振动监测与故障诊断系统,实现了旋转设备的运行状态监测与故障在线诊断和远程协同会诊功能,顺应智能制造的趋势,提供了针对风机等旋转设备运维的可行方案。

高速旋转设备智能感知系统搭建及数据上传方法研究

针对高速旋转设备的特点搭建了物理智能感知系统,重点对系统所产生的传感器数据如何高效上传进行了深入研究。高速旋转设备物理感知系统具有采集信号多、采集方式多及数据量大等特点,提出3种上传算法:多线程多行算法可工作于普通单片机系统,上传速率达到0.06~0.07 MB/s,可满足系统工作于趋势值自动采集方式下的上传要求;单进程分页算法要求上传硬件系统为工业级单片机或嵌入式系统,上传速度可达0.7~0.8 MB/s,且稳定,可以满足系统工作于手动采集方式下数据实时上传的要求;多进程并行算法的硬件要求为多运算器设备,上传速率取决于运算器数量,10运算器主机上传速率稳定在约3.4 MB/s,可满足多设备系统任何数据采集方式下数据实时上传的要求。文中所做分析可为旋转机械行业数字化发展提供切实可行的方案。

基于WSN的旋转机械设备故障时频监测方法

由于旋转机械设备结构和振源较为复杂,以单一故障经验设置的阈值无法准确分解多模态故障,为提升故障监测效果,提出基于WSN的旋转机械设备故障时频监测方法。引入集合经验模态分解故障时频信号,分解不同时刻的振动信号,计算IMF分量的能量,结合归一化能量指标和IMF矩阵奇异谱熵指标,完成旋转机械设备故障时频信号分解。根据特征分解结果,运用训练后免疫RBF神经网络监测旋转机械设备故障。实验结果表明,该方法能够缩短监测时间、提高故障监测准确率。

紫菜滤杂装备中吸滤装置动力学仿真及优化设计

针对现有紫菜滤杂装备存在工作效率低、易堵塞等缺点,设计一种无堵塞滤杂装备,其中吸滤装置由组合式滤筒、防异物堵塞的剔除装置等部分组成。基于拉格朗日方程,对吸滤装置进行动力学建模和仿真,分析多工况下滤缝宽度和滤筒转速两个参数对吸滤效率的影响。结果表明,滤缝宽度为0.6 mm、滤筒转速为200°/s(33 r/min)时,设备吸滤效率最高。基于仿真结果,确定三个试验因子的取值范围,以滤杂率和吸滤时间作为响应指标,利用Minitab软件设计三因素三水平试验,建立响应面回归模型。优化结果表明,当滤缝宽度为0.6 mm、滤筒转速为33 r/min、出料口流量为16 m 3/h时,滤杂率为98.44%,吸滤时间为2.72 min。

先进管理技术在提高转动设备可靠性中的应用

上海赛科石油化工有限责任公司烯烃工厂有500多台透平、压缩机、风机、泵等各类转动设备。文章以案例的形式对设备运行周期各类转动设备出现的故障原因进行了分析,并采用一系列先进管理系统和技术解决相应的问题,从而提高了转动设备的机械完整性和运行可靠性,确保装置安全、连续、长周期运转。

锥形无键联轴器轮毂的拆装要点分析

锥形无键联轴器轮毂设计通常采用过盈装配,普遍用于高速、传递扭矩大的机组,其主要作用是通过过盈配合的摩擦力来防止联轴器轮毂在轴头发生轴向或径向移动,保证机组平稳运行。运行后的机组,其无键联轴器轮毂和轴头的摩擦力会增大,从而造成轮毂拆装难度增大,如果轮毂拆装过程中出现故障,将直接影响整个机组甚至装置的平稳运行。这项拆装技术一般仅为厂家现场服务人员所掌握,如遇到需要拆装轮毂的情况,现场检维修人员较难解决。文章介绍了典型的BB5型高压离心泵在检修过程中拆装联轴器轮毂的工艺要点和难点,具体阐述了利用手持高压油泵和低压油泵并结合现场实践顺利拆装无键联轴器轮毂的技术要点及注意事项,可为同类型机组的检维修工作提供参考和借鉴。

燃气轮机动叶叶顶加工专用卧式磨削设备结构设计

重型燃机透平旋转叶片叶顶加工是叶片成型的关键工序,该工序加工精度决定了叶片顶部与其他部件装配间隙,该间隙大小可能会影响燃机运行做功效率,所以叶顶距转子中心回转半径关键尺寸需要准确控制。然而,不同规格功率的燃气轮机旋转叶片回转半径各不相同,需设计一种能适合不同回转半径叶片叶顶加工的自动化设备。针对耐高温镍基合金材料叶片加工特性硬化、热导性能差、切削力大等特点和传统CNC及电火花加工效率低、刀具损坏快、加工成本较高等问题,采用磨加工工艺与数字化控制相结合的方法开发一种磨削全自动化加工设备。该设备可以自动精确模拟不同规格燃机叶片回转中心实现不同回转半径的变化,同时可以模拟叶片绕转子中心旋转摆动动作;通过数字化实现叶片摆动大小角度的控制、可自动变换角度的磨削进给机构实现不同角度形状叶顶的磨削加工。试验结果表明,该设备功能达到设计要求且加工精度足够满足叶片叶顶加工公差,可用于批量生产。

改进整数线性规划法的农机配备研究

山东省小麦玉米规模化轮作生产下机械效能未充分发挥,存在动力机械与机具配套比低、农机动力与资金浪费问题,主流的整数线性规划农机配备法不适配山东省中小型农业新型经营主体。在对小麦玉米周年轮作全程机械化技术模式调研后,对小面积耕作时农机配备模型采用增设租赁农机服务进行改进。通过验证计算,模型优化后年成本为47 922元,相比未优化前模型成本210 392元下降77.22%;农业机械的配备量下降63.63%。

转动设备的故障诊断与预防维护策略研究

本论文旨在研究石油化工企业中转动设备的故障诊断与预防维护策略,以提高设备运行的可靠性和安全性,降低生产事故的发生率,促进生产效率和经济效益的提升。第一章介绍了研究的背景、目的和意义。第二章系统地探讨了转动设备的故障分类与诊断方法,涵盖了振动异常、润滑问题、轴承损坏等常见故障类型,并介绍了振动分析、红外热成像、声音诊断等诊断方法。第三章强调了预防维护策略在石油化工企业中的重要性,探讨了预防维护的概念、意义以及实施的必要性。第四章通过实证研究分析了石油化工企业中的转动设备故障案例,总结了故障原因及相应的预防维护策略。第五章着重讨论了预防维护策略的设计与实施,提出了针对性的维护计划,并介绍了实施策略和监控调整方法。第六章对全文进行了总结和展望,强调了预防维护是一个持续改进的过程,需要不断探索和优化。通过本论文的研究,石油化工企业可以更好地管理和维护转动设备,提高生产效率,降低运营成本,实现可持续发展。

基于FCM算法的中小型转动设备故障检测研究

针对现有算法在中小型转动设备故障检测中存在的收敛速度慢、故障识别率低等问题,提出一种基于FCM融合算法的故障检测方案研究。对原始故障集做降噪处理,基于模糊熵值理论在多尺度条件下提取故障向量的隶属度;利用GA算法优化FCM算法的迭代性能和收敛性能,分别更新故障特征向量模糊隶属度矩阵和聚类中心矩阵,以达到改善聚类精度,提高故障识别率的目的。实验结果显示,该算法在不同的聚类中心数量及故障类别的条件下,能够获得更好的聚类效果和更高的收敛速度,训练集合和测试集的平均故障识别分别可以达到99.19%和98.23%。

大型湿法磷酸装置过滤设备选型

随着湿法磷酸技术的发展和装置的大型化,过滤设备选型的科学性及合理性越来越引起行业的关注。通过阐述过滤设备的过滤原理及影响因素,介绍了湿法磷酸生产中3种常用过滤设备特点,从技术性及经济性等方面进行分析,并结过滤机在磷酸装置中的工程实际应用,给出了过滤设备的选型建议。