基于三维特征建模的叶片泵CAD系统研制

在总结叶片泵设计原理与优化方法的基础上,提出了开发叶片泵CAD系统的总体方案论述了MDT软件平台上用Visual C 开发研制叶片泵CAD系统中所采用的面向对象程序设计方法、动态调控与实时效果技术、三维特征造型及容错处理等关键技术与实现方法,该系统的特点是融合二维与三维为一体,为用户提供方便友好的叶片泵设计、分析、绘图与修改荼的设计环境。     

进水、出水泵站联动在污水厂自控系统中的应用

本文介绍了在大型污水厂泵站工程中,如何搭建自动控制系统,如何采用组合联动的自动控制方案,把厂内进、出水泵站连接起来,组合控制多台定速泵及调速泵。合理的配送进、出厂污水流量。     

基于PLC的变频调速恒压供水系统的分析

介绍了一种替代常规水塔供水的基于PLC的变频调速恒压供水系统的构成、工作原理和具体实现方案.该系统采用VVVF变频器调节电机转速方式自动调节供水泵电机的转速和投入、切除运行水泵.将原来“先启后停”方式变为“先启先停”方式,全自动完成水泵的启动运行及切换,保证供水水压稳定,PLC控制的电机轮换程序,使各台水泵进行轮转,延长了水泵的使用寿命.     

ORC涡旋膨胀机旁通阀/开启阀切换工况系统性能参数变化研究

通过ORC试验台开展热态试验,获取系统稳定运行时,膨胀机旁通阀和开启阀切换后蒸发器出口压力及温度的变化以及系统其他部件性能参数变化规律。试验结果表明:膨胀机旁通阀和开启阀切换时,系统总的阻力特性会发生变化,继而隔膜泵的出口压力随系统阻力特性发生变化,从而导致ORC各部件都出现对应的性能参数变化。通过阻力变化特性和设备响应规律的研究,为膨胀机和减压阀匹配设计以及膨胀机故障诊断提供了相关的指导。     

煤矿井下主排水泵自动控制系统的应用与研究

煤矿井下主排水泵自动控制系统是通过自动检测水仓水位及相关参数,能够自动控制水泵适时启动、停止,合理调度轮换工作.该系统的成功应用实现了煤矿主排水泵的自动化控制,最终达到减人提效、无人值守的目的.     

伺服电机控制高压大流量双泵液压动力系统研究

由伺服电机和液压泵组成的新型泵控系统已经应用于液压机械设备中,为解决大型液压机对液压动力源高压大流量输出的要求,在传统伺服电机泵控系统中引入了高压主泵和低压副泵,并通过双泵切换来实现高压大流量输出。通过控制器与伺服电机控制电机输出转矩和转速,进而实现对输出压力和流量的控制。通过合流阀块实现对双泵合流与分流的控制,进而实现液压系统的大流量或高压力输出。以液压机一个工作循环为基础进行了性能试验,结果表明该液压动力系统满足压力、流量设计要求,响应速度快,控制精度高。     

基于耦合补偿的往复泵同步控制

系统地阐述了电机驱动往复泵输送矿浆峰值分散技术,在分析单台往复泵流量脉动及压力脉动产生原因的前提下,论述了多台泵向同一管路输送矿浆时产生峰值叠加的原因及消除峰值叠加的两个条件,识别最佳分散相角值。针对现有多电机泵协调输送系统,采用电机轴相关的同步控制策略,提出了基于耦合补偿的同步控制策略实现输送矿浆峰值分散。     

Versatile Pump Controller for Continuous Flow Methods

ABSTRACT

A computer-driven pump controller capable of providing voltage, current and pulsed outputs for up to five pumps in analytical systems is described. The controller is ideal for situations which require remote control of speed and direction for many pumps of different types. The design is based on the Advanced Micro Devices 9513 system timer chip and provides 0-10 V, 0-25 mA and pulsed TTL outputs to control each pump. In addition, phase-locked loop circuitry allows feedback for speed regulation of certain pumps. For control of stop/start, direction or other functions, eight independently programmable TTL outputs are provided. The controller is inexpensive and designed to be driven from the parallel printer port of an IBM PC compatible computer for maximum portability. Other uses of the interface are also possible.     

Influence of blade wrap angle on centrifugal pump performance by numerical and experimental study

The existing research on improving the hydraulic performance of centrifugal pumps mainly focuses on the design method and the parameter optimization. The traditional design method for centrifugal impellers relies more on experience of engineers that typically only satisfies the continuity equation of the fluid. In this study, on the basis of the direct and inverse iteration design method which simultaneously solves the continuity and motion equations of the fluid and shapes the blade geometry by controlling the wrap angle, three centrifugal pump impellers are designed by altering blade wrap angles while keeping other parameters constant. The three-dimensional flow fields in three centrifugal pumps are numerically simulated, and the simulation results illustrate that the blade with larger wrap angle has more powerful control ability on the flow pattern in impeller. The three pumps have nearly the same pressure distributions at the small flow rate, but the pressure gradient increase in the pump with the largest wrap angle is smoother than the other two pumps at the design and large flow rates. The pump head and efficiency are also influenced by the blade wrap angle. The highest head and efficiency are also observed for the largest angle. An experiment rig is designed and built to test the performance of the pump with the largest wrap angle. The test results show that the wide space of its efficiency area and the stability of its operation ensure the excellent performance of the design method and verify the numerical analysis. The analysis on influence of the blade wrap angle for centrifugal pump performance in this paper can be beneficial to the optimization design of the centrifugal pump.     

混凝土泵排量的测量方法

介绍了一种新型混凝土泵排量计量系统的设计思想，包括产品工业背景、数学物理模型、测量原理与公式推导、系统所需算法的实现，最后给出了系统初步的实验结果和性能分析。     

提高离心泵可靠性的若干措施

现代化的生产中需要越来越多的高流量、高扬程离心泵,并对这些离心泵的可靠性也提出了更高的要求。故对影响离心泵可靠性的原因进行了分析,从离心泵的设计制造环节、安装维护角度,以及选型、操作、检修等过程进行了可靠性研究;探讨了提高离心泵可靠性的措施,为离心泵的设计研究提供依据,对于指导设计具有实用意义。     

Analysis of interaction between geometry and efficiency of impeller pump using rapid prototyping

Design aids available today might have helped the pump designers to bring about theoretically the most efficient pumps, but the production technology and quality control during manufacture has not kept pace with such achievements in realizing the goals of developing energy efficient pumps. Pump designers often face the problem of selecting and optimizing a number of independent geometrical parameters whilst aiming at the desired efficiency from the pump. The only option is to approximate the theoretical design with experimental findings iteratively until the end result is achieved. Tremendous development of advanced manufacturing technology and computer technology has made rapid prototyping and computational fluid dynamics (CFD) techniques the right alternative method of reaching the target. Centrifugal pump impeller geometry, which contributes maximum complexity in flow during pump design, has been analysed in this work based on the parameters derived through computer-aided design (CAD) and CFD analysis. Using selective laser sintering, technique the impeller designed by CAD and two standard impellers commercially available for the same duty requirement is manufactured and their performance is tested to know their hydraulic efficiency. Results obtained from this work are useful for standardising pump impeller design and for developing energy-efficient pumps.     

Multimodel PD-control of a pneumatic actuator under variable loads

In this paper, a multimodel controller is designed and implemented to a variably loaded pneumatic actuator. A particular design of the pneumatic system with one PWM-driven switching valve is utilized which has a quasilinear input–output behavior under constant load conditions. Therefore, under a constant load, position control is properly accomplished by a linear PD-controller. In order to use the system in variable load applications such as robot actuators, a multimodel controller is designed based on the PD-controllers. For this purpose, a number of constant loads are considered and corresponding to each load, a linear model is identified and a PD-controller is tuned for the system. Then, a switching algorithm is applied which determines the best model and selects the corresponding controller in any load condition. Also, for the realization of the D-action in PD-controllers, a Kalman filter is designed to observe the velocity instead of direct differentiation of the output position. Experimental results indicate the high performances of the multimodel controller under variable load conditions.     

我国最大的海上起重机轴承在轴研科技下线

我国目前最大的海上起重机专用轴承日前在洛阳轴研科技股份有限公司第二产业园重大型轴承生产车间下线。该轴承为三排滚子结构的转盘轴承,外径尺寸达6．82米,重24吨,创造了轴研科技生产轴承的最大尺寸记录。该轴承将安装在我国首台最大的700吨海上起重机上,主要用于海上风电安装、海上施工和大型的桥梁建设。     

Flow uniformity in a multi-intake pump sump model

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a single pump operation in a semi-infinite basin with no close walls or floors and with no stray currents. Therefore, flow into the pump intake is with no vortices or swirling. However, pump station designers relying on these curves to define the operating conditions for the pump selected sometimes experience reductions of capacity and efficiency, as well as the increase of vibration and additional noise, which are caused by free air mixed with the pump inlet flow. Therefore, sump model test is necessary in order to examine the flow structure around pump intake. In this study, flow uniformity according to the flow distribution in the pump intake channel is examined to find out the cause of vortex occurrence in detail. A multi-intake pump sump model with 7 pump intakes and a single-intake pump sump model are adopted for the investigation. Furthermore, effectiveness of anti-submerged vortex device (AVD) for the suppression of the vortex occurrence in a single pump intake, as well as in a multi-intake pump sump model has been examined by the methods of experiment and numerical analysis. The results show that most high value of flow uniformity is found at the inlet of pump intakes #3 and 5 in the multi-intake pump sump with 7 pump intakes. Therefore, when the pump station is designed, the flow patterns at the upstream region of pump intake inlet in the forebay diffusing area should be to consider in detail because the unbalanced flow at the channel inlet region gives considerable influence on the vortex occurrence around bell-mouth. Strong submerged vortex can be successfully suppressed by AVD installation on the bottom of pump intake channel just below the bell mouth.     

无阀压电泵的流固耦合仿真及试验验证

提出利用结构分析软件ANSYS和流体分析软件ANSYS CFX对无阀压电泵进行流固耦合仿真分析,以研究无阀压电泵的输出性能。分别对进口在中间出口在一侧、出口在中间进口在一侧、进出口对称布置的3种不同结构形式的无阀压电泵进行了流固耦合仿真分析。结果显示,上述3种无阀压电泵中,出口在中间进口在一侧结构形式的无阀压电泵的宏观输出流量最大。制作了3种无阀压电泵的试验样机,并搭建了相应的试验测试系统,在幅值为45 V、频率为0~700Hz的正弦信号激励下对其输出流量进行了测试。结果表明,3种不同结构形式的无阀压电泵的最大输出流量分别为3.8、6.0和4.0ml/min,出口在中间进口在一侧的压电泵输出流量最大,与流固耦合仿真分析的结果相吻合,验证了本文提出的流固耦合仿真分析的方法可以指导压电泵的设计。     

A novel high-temperature and high-pressure hydraulic pump based on mononeuron control

Based on structures and characteristics of traditional hydraulic pumps, this paper proposes a novel high-temperature and high-pressure hydraulic pump (HHHP) that can work under 150°C and 28 MPa to overcome problems of traditional high-temperature plunger pumps. The HHHP is designed with the structure of mechanical division and double cylinder parallel. The control signals of two cylinders are two separate triangle waveforms with 90° phase difference. Because the output waveforms of two cylinders have the same characteristics as the control signals, the HHHP can obtain a stable output after two separate waveforms are superposed. A mononeuron self-adaptive PID control algorithm is also improved by modifying parameters K and η. Two improved controllers are used to control the two cylinders, respectively, making two displacements of plungers match each other. Therefore, reduced fluctuations and stable pressure output is obtained. Besides simulation, tests on the built prototype test system are carried out to verify the performance of HHHP. Results show that the improved control approach can limit fluctuations to a lower level and the HHHP system attains good outputs under different signal periods and different pressures.     

Performance study based on inner flow field numerical simulation of magnetic drive pumps with different rotate speeds

Magnetic drive pump has gotten great achievement and has been widely used in some special fields.Currently,the researches on magnetic drive pump have focused on hydraulic design,bearing,axial force in China,and a new magnetic drive pump with low flow and high head have been developed overseas.However,low efficiency and large size are the common disadvantages for the magnetic drive pump.In order to study the performance of high-speed magnetic drive pump,FLUENT was used to simulate the inner flow field of magnetic drive pumps with different rotate speeds,and get velocity and pressure distributions of inner flow field.According to analysis the changes of velocity and pressure to ensure the stable operation of pump and avoid cavitation.Based on the analysis of velocity and pressure,this paper presents the pump efficiency of magnetic drive pumps with different rotated speeds by calculating the power loss in impeller and volute,hydraulic loss,volumetric loss,mechanical loss and discussing the different reasons of power loss between the magnetic drive pumps with different rotated speeds.In addition,the magnetic drive pumps were tested in a closed testing system.Pressure sensors were set in inlet and outlet of magnetic drive pumps to get the pressure and the head,while the pump efficiency could be got by calculating the power loss between the input power and the outlet power.The results of simulation and test were similar,which shows that the method of simulation is feasible.The proposed research provides the instruction to design high-speed magnetic drive pump.     

乳化液泵站变频恒压控制系统的研究

针对目前采用的由多台小流量乳化液泵组成的泵站,提出变频的控制方式,并进行变频控制系统硬件和软件设计。通过压力传感器检测泵站出口压力,采用变频技术调整乳化液泵电机的转速,达到控制泵站出口压力相对恒定的目的。     

Design principles for low-noise multistage centrifugal pumps in power plants

Basic design principles for centrifugal pumps with low vibrational activity are considered. Increase in pump vibration is due not so much to residual rotor imbalance as to design and technological factors, some of which are intrinsic to multistage pumps and cannot be eliminated by any means.