微小型静电泵的设计(3)

分别详细介绍了微型泵、大流量泵和串接双泵的设计原理及方法,给出了不同状态下参数计算的详细步骤,并绘制出系列图和表格直接应用于微型泵、大流量泵及串接双泵设计.另外还讨论了用不锈钢代替钛作为激励膜的处理方案,描述了串接双泵抽液和出液状态,并阐述了串接双泵的提压原理.因为静电泵的上腔高度明显影响泵膜的抽压力,所以本设计的意义在于如何给上腔充压,泵膜将向下鼓起,可防止碰壁短路现象.特别是膜鼓起量比较大的大容量泵.全文阐述的理论和提供的图、表为微型泵、大流量泵和串接双泵的参数设计提供了实际数据,为静电泵设计者提供示例,以作比较参考.     

一种新型压电式双向无阀微泵的研制

采用氧化、光刻、腐蚀、键合等MEMS技术,研制了一种硅基压电式双向无阀微泵,泵的外形尺寸为30×14×3 mm3,泵腔体体积约10 mm3.通过大量试验测试,得到了泵压、流量与工作频率、波形、电压幅值之间的关系.当工作电压为110 V、频率为40 Hz时,微泵的正向最大泵压为120 mm水柱,频率为50-90 Hz时,最大流量70μl/min;当频率为35 Hz时,微泵的反向最大泵压为70 mm水柱,最大流量56μl/min.     

磁力驱动微泵设计及优化

为提高收缩/扩散管无阀微泵的性能,设计了磁力驱动式无阀微泵,并利用ANSYS软件对微泵的整流部件收缩/扩散管和单腔微泵整体结构进行流体仿真,得到了微泵的结构优化参数.仿真和实验结果表明,流量随着管长、最小宽度、扩张角、泵腔半径的增大存在极大值.磁驱动微泵的流量在驱动电压12 V、驱动频率为25 Hz时达到最大值.     

新型压电微泵的结构设计与理论分析

微泵在微流控化学分析芯片中有很大的应用前景,日益成为人们研究的热点。从结构设计、理论分析和工艺加工3个方面研究了微阀与微泵,设计出用压电驱动和聚二甲基硅氧烷(PDMS)作为泵膜的集成微阀与微泵,其特点是原理新颖、结构简单、易于加工、操作方便。结构主要是由PDMS泵膜、硅片和压电驱动器组成,其中,PDMS既是泵膜和缓冲单元,也是主动阀片。在直流电压的驱动下,其工作状态是微阀,阻止流体的单向流通,在方波信号的驱动下,其工作状态是微泵,实现流体的吸入与泵出。给出各种几何参数、工作原理和工艺流程。     

多通道微量注射泵控制系统的设计

微量注射泵是广泛应用于医疗、生物工程、基因工程、化学工程及环境工程等领域的一种数字化、智能化的精密仪器;为了提高微量注射泵的加注精度和加注效率,文章设计通过上位机及同步控制板可以同时控制多台精密微量注射泵工作;由上位机设置加注模式及工作参数,通过串口下载到多台注射泵,同步板控制多台注射泵同时精确加注;实验结果表明,每台注射泵的加注精度满足要求,系统抗干扰能力强,性能稳定,工作效率显著提高。     

基于LabVIEW的体外循环用离心式血泵机械参数测试系统研究

在离心血泵的研制过程中,流量与灌注压作为血泵的两个重要性能指标,是关键的检测参数;而扭矩是离心血泵驱动能力的重要体现,因此,对扭矩的测试也至关重要;针对离心血泵流量8L/min,灌注压50kPa的设计要求,设计了基于虚拟仪器技术的离心式血泵压力、流量和扭矩的测试系统,为实现离心式血泵的测试、分析和优化提供重要的试验方法;结果表明:该测试系统能够满足对离心血泵流量、压力和扭矩等机械参数进行测试的要求。     

汽油机共轴泵测试系统和测试方法

长期以来汽油机共轴泵都是进行单泵测试,只考核泵的性能,这就不能准确地反映机组性能。本文介绍汽油机共轴泵在试验室测试流量、扬程、转速、效率、汽蚀余量等主要性能参数的测试系统和测试方法,该测试系统和测试方法对汽油机共轴泵进行整个机组考核,全面反映机组性能,并通过多次测试验证,符合GB/T3216—1989《离心泵、混流泵、轴流泵和旋涡泵试验方法》的要求。     

电潜离心泵内流场及外特性的数值模拟分析

针对目前油田使用的两种不同叶导轮结构的电潜离心泵,包括传统径向流泵和聚驱用混向流泵,采用计算流体动力学(CFD)研究方法,建立电泵内流场的数值仿真,在流量80～200m³/d范围内,研究泵输送不同运动黏度为1～40mm²/s介质时特性差异。在介质黏度为1和40mm²/s,流量为80～180m³/d工况下,使用FLUENT软件选用标准k-ε湍流模型和SIMPLE算法进行求解,分析两种泵在不同工况下的内部流场变化规律,通过流场分析探究叶轮结构对泵外特性的影响机制。仿真得到泵的扬程、效率曲线,发现泵性能出现变化的工况点与叶轮内流场分析结果相对应,并根据泵叶轮的内流场分布和泵的性能曲线分析两种泵所适用的工况。结果表明,径向流泵适用于大流量和高黏度工况,混向流泵适用于较低流量和中低黏度工况,为不同工况下泵的选择及泵的优化提供理论依据。     

磁力驱动串联式双腔微泵设计及性能测试

针对无阀微泵背压能力较弱等问题,采用MEMS技术制作出不同结构参数的双腔和单腔微泵体,构建了基于电机驱动的磁力式双腔串联无阀微泵测控系统.实验结果表明,泵腔面积相等的情况下,圆形泵腔的微泵流量大于椭圆形泵腔的流量;随着驱动频率的升高,双腔串联微泵的流量呈现高斯分布,并在20 Hz附近处出现流量峰值,微泵的最大流量可达1.5 mL/min,微泵的截止背压为170 mmH2O,双腔串联微泵比单腔微泵的流量增大约80％.     

变转速比例泵小流量特性测试方法

在泵控位置、速度及力伺服控制系统中,比例泵的流量-转速-压力特性对系统控制效果有至关重要的影响,提出一种比例泵流量-转速-压力特性曲面的测试方法:基于所测比例泵低转速下的流量-转速-压力特性点云数据,应用移动最小二乘拟合法获取比例泵小流量特性曲面.分别对移动最小二乘拟合曲线和恒定加载的泵特性测试数据进行一次曲线拟合,并对比两种方法所拟合后的曲线发现:比例泵转速系数相对误差小于3％;比例泵泄漏系数相对误差在5％左右.上述结果表明,所述方法对于比例泵小流量特性曲面的测试有效,避免了对系统加载繁杂细致的调整,提高了系统的测试效率.     

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.     

微型涡轮发动机电动供油流量控制系统设计

针对微型涡喷发动机的燃油控制要求,选用汽车用电动油泵进行适应性改进作为供油执行装置,详细分析了电动油泵的特性及泵转速无法测量情况下流量控制的技术难点,并以83C552单片机为核心,采用电压负反馈加电流补偿代替转速负反馈、电机通过PWM驱动的方法设计电动油泵流量闭环控制系统。在完成系统建模、PID控制器设计与仿真的基础上进行控制性能试验,试验结果表明所设计的流量控制系统可满足微型涡轮发动机的供油控制要求。     

无人值守泵站自动化技术改造案例

介绍宜兴水务集团泵站自动化控制系统的组成与功能,着重论述改造前后控制方式的变化和达到的效果。     

Non-newtonian laminar flow machine rotor design by using topology optimization

Flow machines are widely used in industry through devices such as hydraulic turbines and pumps. Most part of these devices work with newtonian fluids, however, there are some specific devices dedicated to work with non-newtonian fluids, such as blood pumps. The main function of a blood pump is to have a suitable hydraulic performance while maintaining good haematological compatibility which consists of avoiding hemolysis (release of hemoglobin from red blood cells) and thrombosis (clotting). However, the challenge of improving the performance of these non-newtonian fluid machines requires the solution of an inverse-based design optimization problem, in which an oriented search must be conducted to obtain the optimized design. The rotor is a main component in the non-newtonian pump and the design of rotor topology can play an important role in the pump performance and its haematological conditions. Thus, performance improvement of these devices can be achieved by using topology optimization techniques. The optimization of pump hydraulic performance can be achieved by minimizing dissipative energy and power consumption and for the improvement of the haematological conditions, it is proposed to minimize the vorticity. Thus, in this work, topology optimization techniques are applied for designing the rotor pump such that the energy dissipation, vorticity, and power consumption are minimized considering non-Newtonian fluid. A two-dimensional finite element derived for a rotating frame is applied to model the rotor flow behavior. The modeling predicts the flow field between relative two blades of a rotor without considering the influence of the volute. A modified Cross model is adopted for the non-Newtonian fluid modeling. It is assumed that the fluid is flowing an idealized porous medium subjected to a friction force, which is proportional to the fluid velocity and the inverse local permeability. A porous flow model is considered with a continuous (gray) permeability design variable for each element that defines the local permeability of the medium and allows the transition between fluid and solid property. The design optimization problem is solved by using the method of moving asymptotes (MMA). Numerical examples are presented to illustrate this methodology aiming blood pump applications. A comparison among designs obtained by considering newtonian and non-newtonian fluid is included. Finally, it is verified that an improvement of the hemolysis index can be achieved by minimizing the vorticity in the rotor.     

考虑汽蚀影响的给水泵仿真建模及实现

该文根据蒸汽动力装置模拟器的研制需求,讨论了考虑汽蚀影响的给水泵仿真建模和实现方法。蒸汽动力装置中使用的给水泵动态特性变化很大,给水泵作为变转速泵的特性模拟在整个蒸汽动力装置热工水力特性模拟中占有非常重要的地位。由于给水泵性能受汽蚀影响很大,因此考虑汽蚀对给水泵性能的影响对于提高模拟器在正常工况和事故工况下的仿真精度有很大意义。该文构建的模型形式简单,计算精度高,覆盖的给水泵运行工况宽。该文提出的仿真模型和数值方法对于同类型泵的仿真建模和计算分析具有一定的参考价值。     

Analysis of double-chamber parallel valveless micropumps

The characteristics of a double-chamber valveless parallel micropump are analysed using a one-dimensional non-linear model. The relationships between the mean volume flux, pressure difference and (measurable) characteristics of the pump are derived in a closed-form expression which are validated against the numerical solutions. These results show that when pump chambers are driven exactly out of phase, the volume flux is maximum and the variation of the pump chamber pressure is (significantly) reduced. The model predictions were tested against the experimental results of Olsson et al. (Sens Actuators A Phys 47:549–556, 1995) for both in and out of phase pumps. The mean volume flux decreases linearly with pressure rise. For both cases, the agreement is good and is an improvement over previous analytical models. The implications of these results for optimal pump design are discussed.     

多足步行机器人液压控制系统研究现状与发展趋势

针对多足步行机器人液压系统能量损失较大、结构相对单一及控制策略相对复杂等问题,从机器人液压系统和控制策略2个方面分析了多足步行机器人液压控制系统现状．将液压系统从泵源、液压执行器和液压控制结构3个方面分别阐述．从动力来源和油路结构介绍了泵源,从结构分类、一体化集成和特殊功能简述了不同液压执行器的应用,从阀控液压系统和泵控液压系统介绍了液压控制结构．从自由空间和约束空间两方面介绍了系统控制策略．多足步行机器人液压系统的发展方向包括小型化、轻量化、节能降耗、降低噪声和泄漏以及对控制策略的改进．     

Representations and evolutionary operators for the scheduling of pump operations in water distribution networks

Reducing the energy consumption of water distribution networks has never had more significance. The greatest energy savings can be obtained by carefully scheduling the operations of pumps. Schedules can be defined either implicitly, in terms of other elements of the network such as tank levels; or explicitly, by specifying the time during which each pump is on/off. The traditional representation of explicit schedules is a string of binary values with each bit representing pump on/off status during a particular time interval. In this paper, we formally define and analyze two new explicit representations based on time-controlled triggers, where the maximum number of pump switches is established beforehand and the schedule may contain fewer than the maximum number of switches. In these representations, a pump schedule is divided into a series of integers with each integer representing the number of hours for which a pump is active/inactive. This reduces the number of potential schedules compared to the binary representation, and allows the algorithm to operate on the feasible region of the search space. We propose evolutionary operators for these two new representations. The new representations and their corresponding operations are compared with the two most-used representations in pump scheduling, namely, binary representation and level-controlled triggers. A detailed statistical analysis of the results indicates which parameters have the greatest effect on the performance of evolutionary algorithms. The empirical results show that an evolutionary algorithm using the proposed representations is an improvement over the results obtained by a recent state of the art hybrid genetic algorithm for pump scheduling using level-controlled triggers.     

Unsteady flow behaviors in an obstacle-type valveless micropump by micro-PIV

In this paper, a PZT micropump excited by amplified squarewave signals with various frequencies was used to study the transient flow behaviors in an obstacle-type valveless micropump. A micro-particle-image-velocimetry (micro-PIV) with an external trigger was developed to obtain flow fields at the outlet and around the obstacle with various phases in a cycle. In comparison with previous studies on the pump performance, such as pump pressure and volume flow rate, more detailed information about the pump was obtained. The velocity profiles and periodic sectional mean velocities exhibited the unsteady flow nature. The total net flow generation efficiency per cycle was obtained experimentally by integrating the phase-dependent velocities. The flow recirculation around the obstacle was observed and quantified to investigate the influence on the pump performance. The duration, circulation, and the size of the recirculation regions indicated that this flow behavior could enhance the flow-directing capability. These results are very useful for the design and improvement of obstacle-type valveless micropumps.     

基于神经网络的抽油机故障诊断

自组织特征映射网络（Self-Organization Map,SOM）是一种具有强大的自学习功能、良好的自组织性和自适应性的神经网络,能够将输入数据映射到输出神经元阵列中,并保持数据集的拓扑结构和密度分布不变。针对基于传统竞争神经网络的抽油机示功图聚类时分类精度低的缺点,对自组织特征映射神经网络的学习速率和临域的递减方式进行改进,并在Matlab环境下进行仿真验证。仿真结果表明,本文所采取的改进能有效的提高聚类的精度和准确性。