含沙水体对叶轮磨蚀特性的模糊支持向量预测法

分析了含沙水体对抽水泵叶轮磨蚀的原理及危害.以江南某水厂1～6号机组采用的日本荏原公司500VYM水泵大修数据为基础,针对样本极为有限、影响因素复杂多变的情况,提出采用模糊支持向量机对叶轮磨蚀特性进行预测.为各机组开机调度、大修时间、人员、经费安排、备件购置等提供决策支持.对相应算法进行了推导分析,并与人工神经网络、常用核函数等方法进行了实验对比,本算法具有更优的性能,可为这类问题的处理提供参考.     

浅谈在电解铝车间中间通道提升梁工作原理及计算机在设计中的应用

正电解槽、铝电解多功能机组是电解铝生产及操作工艺过程中的关键设备,处于高温、强磁、噪声、高粉尘、有害气体的环境中。对于关键设备的大修就带来了相当的困难,现场就地大修不但质量难以保证而且维修时间长,工人劳动强度大、安全存在隐患等现象发生。同时就地大修时也严重影响车间生产的正常进行。这样采用集中大修通过采用专用设备在专门的大修车间里进行大修与维护就显得非常重要。而集中大修需要把要修的设备转运到大修车间进行,根据国外的经验转运铝电解多功能机组及阴极车等需要设计专门     

模糊神经网络控制在风力发电系统中的应用

风速超过额定值后,需要有效调节风电机组吸收功率并限制叶轮载荷不超过设计的限定值.在分析风力发电系统原理的基础上,采用自适应模糊神经网络控制器控制桨距角,使机组能保持在额定功率附近发电,仿真结果表明了本文提出方法的有效性.     

某核电厂汽轮机中压调节阀故障研究与处理

为了妥善自主处理某核电厂汽轮机中压调节阀故障及查找原因,系统性梳理与分析了同类机组运行经验及当前机组的阀门改进项。采用现场试验的方法,分析故障机组阀门的试验数据,确认了液压油质、比例阀控制为非致因因素;分析在近期大修商运机组的新旧比例阀性能比对试验的数据,进一步确认了新比例阀在该机组上的工作性能弱于旧比例阀。通过分析在调试机组接入比例阀接口装置测量得到的压降数据和尝试调整减压阀定值,可复现与消除故障。结果证明了减压阀定值设定不当是导致阀门故障的原因。该研究为后序机组阀门故障处理提供了借鉴。     

某电源车双频机组电性能综合测试仪设计

由于目前部队所装备的某电源车没有机组参数检测设备,为了保证车内的双频发电机组经过大修以后能够满足出厂要求,研制了电源车双频机组电性能综合测试仪。该测试仪采用智能检测技术,可以对双频机组的电性能参数进行高精度、高速度智能测试和波形分析。实际应用表明该测试仪的自动化程度高,测试精度高,准确度高,能满足各项指标要求,具有广阔的应用前景和发展潜力。论文介绍了该测试仪的主要功能、战术技术指标、组成及工作原理。     

基于紫金桥软件的风电机组监控信息系统的研究与实现

风力发电是将风能转换成电能,风能推动叶轮旋转,叶轮带动转动轴和增速机,增速机带动发电机,发电机通过输电电缆将电能输送地面控制系统和负荷。风力发电技术是一项多学科的,可持续发展的,绿色环保的综合技术。在信息化与自动化融合的今天,风力电厂的自动监控平台自然离不开软件的支撑,基于此,本文提出了基于紫金桥软件的风电机组监控系统解决方案,实现了对风电机组及电力传输的自动监控。     

基于激光雷达测风仪的风电机组偏航优化控制方法

为了能通过短时安装激光雷达测风仪对传统的风向标测得偏航误差进行修正,提高风电机组的对风精度,根据激光雷达测风仪的风向检测原理和实测数据的分析,总结了叶轮前方风向变化的规律,确定了要检测到不受机组干扰的风向的最佳检测距离和检测光束的锥角;经过不同风速段的偏航误差特点分析,采用了分高、低两个风速段,用最小二乘法去拟合从本地...     

离心叶轮内部流场计算机仿真及分析

大型电机的冷却通常采用直叶片的离心叶轮,其内部的流动结构及其随工况的变化对叶轮性能及电机冷却效果有重要影响.为减少对实验的依赖,提高改型设计的可靠性,采用全三维的Navier-Stokes方程,建立了离心叶轮的计算机仿真模型,结合湍流模型及相应的计算网络及边界条件,可以完成对叶轮性能及内部流场的计算.用仿真模型针对一实际应用的离心冷却风机叶轮进行了数值仿真计算.并对计算结果进行了详细的对比分析,得出了不同工况下详细的流场结构,包括相对速度在叶轮通道中的分布及相对速度流线图.揭示了小流量工况下流动分离及效率降低的机理,将冷却风扇叶轮的总体性能与内部的流场结构进行了关联.研究结果表明离心叶轮内部流动分离是导致其性能下降的主要原因.     

FBD No8.0/2×55 kW型局部对旋式通风机叶轮的结构分析

为进一步探究局部对旋式通风机叶轮结构的可能优化路径,以FBD No8.0/2×55 k W型对旋通风机为研究对象,通过三维建模和有限元分析方法,对该通风机叶轮进行力学分析与模态分析,根据分析结果确定叶轮结构需要改进的方向,而后采用NACA4415翼型叶片对叶轮结构进行优化,结果显示,优化后的叶轮叶片应力和应变显著降低,且发生共振的风险大大降低,表明本次分析与优化工作具有一定的现实意义。     

采用逆向工程对叶轮的建模及其数控加工的研究

在设计机械设备时,对于型面异常的元件不能用常用方法对其长度和体积进行测量时,经常采用逆向工程技术对元件进行估测。本文主要在逆向工程技术的基础上,对叶轮进行建模,并针对数控加工技术进行再设计,对叶轮元件的相关参数进行确定,利用叶轮叶片参数扫描的方法,对叶轮叶片进行建模。通过创立了3D边界法,有效去除外部点云的干扰,对于当前的叶轮叶片的建模及其数控加工技术的研究具有参考意义。     

Investigation of an efficient shape optimization procedure for centrifugal pump impeller using eagle strategy algorithm and ANN (case study: slurry flow)

Investigation an efficient shape optimization method for centrifugal pump and other turbo-machine is significant to reduce time consumption of process and increase accuracy and modification. For analysis an efficient shape optimization procedure, slurry flow in centrifugal pump is investigated. Since a centrifugal water pump has been not designed to carry out slurry flows, its performance decreases and energy consumption of this kind of pump increases. Therefore, improvement of performance and reduction of energy consumed for these pumps are the major issues. Since the performance of a centrifugal pump strictly depends on its impeller shape, in this study, the shape of impeller was optimized in order to achieve a higher efficiency for slurry flow. To optimize the impeller geometry and to improve the performance of Berkeh 32–160 pump as for the case study, Artificial Neural Networks (ANN) and Eagle Strategy (ES) algorithms have been coupled with a validated 3D Navier–Stokes equations for two phase flow based on Eulerian-Eulerian model. In the next step, the pump experimentally tested in an established slurry flow test rig in laboratory. Measured data were used to verify the numerical results of initial pump with slurry flow. Finally, the complete numerical characteristic curves of the pump with the optimized impeller were compared to the validated numerical characteristic curves of that with the initial impeller to verify optimization. An efficiency improvement of 3.33% at only 9.9% increasing of head has been obtained for optimized geometry. The results indicated a reasonable improvement in the optimal design of pump impeller and a higher performance using the ES algorithm. Furthermore the ES and PSO algorithm was compared and results shows that ES is efficient than PSO algorithm in this application and this methodology is more efficient than other surrogate methods.     

基于DSP的给水泵运行状态在线监测系统

给水泵在运行过程中的振动信号及其特征信息对给水泵系统的状态监测有重要意义.给水泵运行状态在线监测系统以数字信号处理器DSP为核心,采用以振动监测为主、过程量监测为辅的监测方法,介绍了给水泵运行状态在线监测系统的工作原理,分析了有限冲击响应(FIR)数字滤波算法和快速傅里叶变换(FFT)算法的DSP实现方法.本系统在湖南湘潭电厂使用后,收到良好效果,对辅机故障诊断与检修具有重要的指导意义.     

Microfabricated centrifugal pump driven by an integrated synchronous micromotor

This paper presents the development of a new design of the microfabricated centrifugal force pump. The pumping concept is based on running an impeller (a rotor including permanent magnets carrying straight and backward blades) within an integrated synchronous motor, which can be operated at different rotational speeds to pump water. The impeller is 5.5 mm in diameter, and is 1.5 mm in height. This micropump with 7-straight-blade impeller can operate smoothly up to a rotational speed of 9000 rpm. It can deliver a non-pulsating maximum flow rate of up to 12 ml/min and allows water to be pumped up to a 24 cm water head. Additionally, the micropump with the backward-blade-impeller pump delivered a flow rate of up to 14.3 ml/min. at a rotational speed of 11,400 rpm with no back pressure. The micropump was patterned using a series of microfabrication processes including sputtering, photolithography and electroplating within a clean room. Such a pump can be integrated into a system of a compact size and can provide a wide range of flow rates. It could also be a promising device for use within biological and micro biomedical fields. To our knowledge, this is the smallest centrifugal pump in the world with an integrated electromagnetic synchronous motor that offers such high flow rates.

     

600MW超临界机组凝泵变频控制及效果分析

节能减排是电力行业的一项基本要求,属于考核范围的重要项目之一。在大型发电企业中,各企业都在寻找各种节能减排的方式,凝泵变频控制受到更多的电厂重视和应用推广。本文介绍了浙能乐清电厂在#1机大修过程中对凝泵控制进行了改造,采用变频器控制。根据凝泵变频器的特点和除氧器两个调节阀的特性,对除氧器水位控制策略进行了完善和改进。现场的实际应用表明,改进后的凝泵变频器控制能有效的降低凝泵的耗电量,减小阻力损失,降低企业生产成本,凝泵变频器的控制和除氧器水位调节阀配合在一起能很好的对除氧器水位进行控制。     

基于热式原理的矿用缺水传感器的设计

针对电极式和靶式缺水传感器在瓦斯抽采泵供水状态检测中存在无水时显示有水、有水时显示无水等检测状态不准确的问题,设计了采用热式原理的矿用缺水传感器。该传感器在抽采泵供水管路中设置2个铂电阻;根据介质流动时要带走铂电阻表面的温度来检测这2个铂电阻温差,由此判断供水管道中是否有介质流动。煤矿现场实际运用表明,所设计的缺水传感器检测供水状态准确,运行稳定可靠,同时对外提供了RS485和无源触点等多种标准接口,对实现瓦斯抽采泵的自动控制具有重要意义。     

A fast numerical method for flow analysis and blade design in centrifugal pump impellers

A numerical methodology is developed to simulate the turbulent flow in a 2-dimensional centrifugal pump impeller and to compute the characteristic performance curves of the entire pump. The flow domain is discretized with a polar, Cartesian mesh and the Reynolds-averaged Navier-Stokes (RANS) equations are solved with the control volume approach and the k-ε turbulence model. Advanced numerical techniques for adaptive grid refinement and for treatment of grid cells that do not fit the irregular boundaries are implemented in order to achieve a fully automated grid construction for any impeller design, as well as to produce results of adequate precision and accuracy. After estimating the additional hydraulic losses in the casing and the inlet and outlet sections of the pump, the performance of the pump can be predicted using the numerical results from the impeller section only. The regulation of various energy loss coefficients involved in the model is carried out for a commercial pump, for which there are available measurements. The predicted overall efficiency curve of the pump was found to agree very well with the corresponding experimental data. Finally, a numerical optimization algorithm based on the unconstrained gradient approach is developed and combined with the evaluation software in order to find the impeller geometry that maximizes the pump efficiency, using as free design variables the blade angles at the leading and the trailing edge. The results verified that the optimization process can converge very fast and to reasonable optimal values.     

Numerical flow-field analysis and design optimization of a high-energy first-stage centrifugal pump impeller

Described is the numerical flow-field analysis and design optimization of the first-stage impellers of a so-called high-energy centrifugal pump having two single-suction first-stage impellers and one double-suction second stage impeller. This study has been carried out with the aid of three-dimensional computational-fluid-dynamics calculations, employing the potential-flow approximation of the governing equations. The study was conducted because the first-stage impellers of the pump considered appeared to suffer from severe premature wear due to cavitation attack on the vane leading edges, which situation had to be improved. The analysis carried out for the existing design produced suggestions for improvement, and based on these suggestions a new first-stage impeller design was developed. Subsequently, this new design was numerically analyzed to substantiate its potentially better (cavitation) performance. It appeared that the blade inlet angle of the original impeller design was too excessive at mid span, causing best cavitation performance to occur at 160 percent of the rated flow. The new design has its best cavitation point at the rated flow, and will not suffer from premature wear due to cavitation attack like the existing design. Received: 1 March 1999 / Accepted: 21 September 1999     

离心泵叶轮爆裂转速数值仿真和试验

基于SimXpert对某液体火箭发动机离心泵叶轮进行弹塑性有限元分析,计算离心泵叶轮在离心载荷作用下的爆裂转速,并与在超速试验台上得到的爆裂试验结果进行对比.结果表明,考虑材料非线性的弹塑性有限元计算结果与试验结果误差为0.59%,可应用于离心泵叶轮的强度校核和结构优化. 该离心泵叶轮的爆裂转速为2.716倍的工作转速,对其进行结构轻量化或优化十分必要.     

Development of insertion-type peristalsis pump using pneumatic artificial muscles

This study aims to develop a new type of peristaltic pump that transports high-viscosity and solid–liquid mixture fluids. Pumps capable of transporting such fluids are essential in various situations such as factory transportation, outdoors, and emergencies. These fluids are conventionally transported by positive-displacement and rotodynamic pumps. However, solid–liquid fluids could collide with the impeller of the rotodynamic pump and thereby damage the pump, whereas the positive-displacement pump must be sufficiently large to apply high pressure to the transported fluid. A small pump that can transport these fluids would save factory space and enable outdoor applications such as dredging operations. Thus, we adopted earthworm peristalsis as a model mechanism of fluid transport within a standard plumbing infrastructure. The insertion-type peristaltic pump developed in this study uses an artificial rubber muscle to achieve an earthworm-like mechanism. The capability and energy efficiency of the mechanism is evaluated in water transportation experiments.     

基于ANSYS的离心泵叶轮结构有限元分析

叶轮是泵的核心部分,泵的性能参数：流量、扬程、效率和特性曲线的形状等均与叶轮的设计有重要关系。本文对叶轮结构进行了有限元分析,准确且直观的得到了叶轮在载荷作用下的应力和应变,为叶轮的强度计算提供了可靠依据,验证了有限元建模方法和计算方法的正确性。