The Impact of Temperature on the Electromagnet and Structural Optimization of a Solenoid Valve

The mathematical model of the solenoid valve under varying temperatures is constructed to investigate its performance and enhance heat dissipation balance.The relationship between temperature and electromagnetic force is determined.Electrothermal coupling simulation using COMSOL is conducted,optimizing the outer diameter and length structure parameters of the coil.It is established that the heat dissipation of the coil is influenced by its outer diameter.Subsequently,based on optimized coil structure parameters,an orthogonal experimental design method combined with Ansys Maxwell is employed for simulation solution analysis to study the impact of structural parameters such as length,position,front and rear angles of the magnetic barrier ring in the iron core,armature length,and through-hole size on electromagnetic force.Optimal structural parameters are identified.Results indicate a decrease in steady-state electromagnet temperature by 3-4℃,an increase in the initial electromagnetic force by 32.63%,and a rise in the maximum electromagnetic force by 27.10%.

Dynamic Performance of High Speed Solenoid Valve with Parallel Coils

The methods of improving the dynamic performance of high speed on/off solenoid valve include increasing the magnetic force of armature and the slew rate of coil current, decreasing the mass and stroke of moving parts. The increase of magnetic force usually leads to the decrease of current slew rate, which could increase the delay time of the dynamic response of solenoid valve. Using a high voltage to drive coil can solve this contradiction, but a high driving voltage can also lead to more cost and a decrease of safety and reliability. In this paper, a new scheme of parallel coils is investigated, in which the single coil of solenoid is replaced by parallel coils with same ampere turns. Based on the mathematic model of high speed solenoid valve, the theoretical formula for the delay time of solenoid valve is deduced. Both the theoretical analysis and the dynamic simulation show that the effect of dividing a single coil into N parallel sub-coils is close to that of driving the single coil with N times of the original driving voltage as far as the delay time of solenoid valve is concerned. A specific test bench is designed to measure the dynamic performance of high speed on/off solenoid valve. The experimental results also prove that both the delay time and switching time of the solenoid valves can be decreased greatly by adopting the parallel coil scheme. This research presents a simple and practical method to improve the dynamic performance of high speed on/off solenoid valve.

OPTIMAL CONTROL OF AN ACTIVE SUSPENSION SYSTEMEMPLOYING HIGH SPEED ON/OFF SOLENOID VALVE

Previous studies have confirmed that an active suspension system with high speed ON/OFF solenoid valves could provide the same vibration isolation efficiency as that of system with pressure proportional valve. In this study, by using Linear-quadratic optimization technique and Kalman filter method, an optimal regulator controller with a state observer was designed for the proposed system. Simulation and experimental research was conducted on a quarter car model. The simulation analysis of the system frequency characteristic suggested that the peak value of magnitude response curve in the case of system with an optimal controller would be lowered significantly, and the experiment results also showed that an improvement in the vibration isolation effect was obtained in using the designed optimal controller over the sky hook damper controller.

Optimal Control of Hydraulic Position System Employing High Speed On/Off Solenoid Valve

A hydraulic position system was designed employing two high speed On/Off solenoid valves with PWM(Pulse width modulation) technique and using LQ(Linear Quadratic) optimization principle. Based on the system, the parts of system can be formulated with equations. According to equations, the mathematical model of the system was established. By simulation, the corresponding LQ optimal controller was designed and the PWM signals were generated. The comparison of the simulation and experiment results show that LQ optimal control method with PWM technique employing high speed On/Off solenoid valve can provide better system performance and a high position precision is obtained.

Development of a Novel Parallel-spool Pilot Operated High-pressure Solenoid Valve with High Flow Rate and High Speed

High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system.However,traditional single spool pilot operated valve cannot meet the demands of both high flow rate and high speed simultaneously.A new structure for a high pressure solenoid valve is needed to meet the demand of the underwater driving system.A novel parallel-spool pilot operated high-pressure solenoid valve is proposed to overcome the drawback of the current single spool design.Mathematical models of the opening process and flow rate of the valve are established.Opening response time of the valve is subdivided into 4 parts to analyze the properties of the opening response.Corresponding formulas to solve 4 parts of the response time are derived.Key factors that influence the opening response time are analyzed.According to the mathematical model of the valve,a simulation of the opening process is carried out by MATLAB.Parameters are chosen based on theoretical analysis to design the test prototype of the new type of valve.Opening response time of the designed valve is tested by verifying response of the current in the coil and displacement of the main valve spool.The experimental results are in agreement with the simulated results,therefore the validity of the theoretical analysis is verified.Experimental opening response time of the valve is 48.3 ms at working pressure of 10 MPa.The flow capacity test shows that the largest effective area is 126 mm2 and the largest air flow rate is 2320 L/s.According to the result of the load driving test,the valve can meet the demands of the driving system.The proposed valve with parallel spools provides a new method for the design of a high-pressure valve with fast response and large flow rate.

Influence of eddy current on transient characteristics of common rail injector solenoid valve

Influence of eddy current on transient characteristics of common rail injector solenoid valve was studied in this paper. Experimental investigations of drive current and power source volt- age of both drive current ascending and descending process were conducted on a common rail injec- tor solenoid valve. A new discretizing calculation method of solenoid valve flux linkage was put for- ward for the first time based on the experimental results and drive circuit principle, and flux linkage of both drive current ascending and descending process were evaluated. New inductance calculation methods for drive current ascending and descending process respectively were also presented. Influ- ence of parasitic inductance was evaluated. Results indicate that the air gap, under which the transi- ent flux linkage of the solenoid valve is the biggest, varies with drive current due to eddy current. Flux linkage of drive current descending process is bigger than that of drive current ascending process under the same drive current and the same air gap width. Eddy current can reduce the delay between the time that drive current begins to descend and the time that armature begins to move downward. Inductance of drive current descending process is bigger than that of drive current as- cending process over larger scope of drive current, but the difference becomes smaller with the in- creasing of air gap width. The differences of both flux linkage and inductance between drive current ascending and descending process are caused by the eddy current in core and armature materials.

Multi-domain modeling and simulation of proportional solenoid valve

A multi-domain nonlinear dynamic model of a proportional solenoid valve was presented.The electro-magnetic,mechanical and fluid subsystems of the valve were investigated,including their interactions.Governing equations of the valve were derived in the form of nonlinear state equations.By comparing the simulated and measured data,the simulation model is validated with a deviation less than 15%,which can be used for the structural design and control algorithm optimization of proportional solenoid valves.

INVESTIGATION ON THE DYNAMIC RESPONSE PERFORMANCE OF A NOVEL THREE-WAY SOLENOID VALVE

Objective A novel high-speed three-way solenoid valve is developed, which is used for the common-rail injection system equipped on DME powered engine. In order to improve the dynamic response performance of the three-way solenoid. Methods Experimental studies have been conducted to investigate the effects of spool stroke, drive voltage, negative demagnetizing pulse and two drive schemes on the dynamic response performance of the three-way solenoid valve. Results The results show that the dynamic response performance of the three-way solenoid valve can be remarkably improved by shortening the spool stroke and increasing the drive voltage. Simultaneously, the difference between the response time of closing valve and that of opening valve decreases. At each different drive voltage, there exists an optimal negative demagnetizing pulse corresponding to the same positive exciting pulse. At this optimal pulse, the dynamic response performance of the three-way solenoid valve is the best. In addition, the high drive voltage can lead to the smaller optimal negative demagnetizing pulse. It is also indicated from the experiments that the dynamic response performance of the three-way solenoid valve is better when the NO.1 drive scheme is adopted. The lower drive voltage results in the larger difference between the dynamic response performances for the two drive schemes. Conclusion The dynamic response performance of a novel three-way solenoid valve is good.

Simulation research on dynamic performance of the new type high-pressure solenoid valve

To improve energy density,the transportation,storage,and operations of hydrogen,methane,and compressed air vehicles currently require high-pressure compression.High-pressure solenoid valve becomes the vital element to above system.In order to reduce leakage and aerodynamic force influence,a new type high-pressure solenoid valve was proposed.The simulation model which included electromagnetic model,aerodynamic force model was established by means of the nonlinear mathematic models.Using the software MATLAB/Simulink for simulation,the dynamic response characteristics of high-pressure pneumatic solenoid valve were obtained under different pulse width modulation(PWM)input control signals.Results show that,first of all,the new type of high-pressure solenoid valve can meet the switch requirement.Secondly,the opening movement and closing movement of the spool lags the PWM rising signal,and the coil current fluctuates significantly during the movement of the spool.Lastly,on/off status of high-pressure valve cannot be represented by the duty cycle.This research can be referred in the design of the high-pressure solenoid valve..

The Characteristic Analysis of the Electromagnetic Valve in Opening and Closing Process for the Gas Injection System

In this paper, the mathematical model of solenoid valve in the fuel injection system of gas engine is built. Simulation software Matlab/Simulink are employed to analyze the impact which the voltage, number of the coil turns and air gap width may produce to the open and close characteristics of the solenoid valve. The ideal response characteristics are got through the calculation. An optimal scheme which satisfies the operation requirements is put forward. The driving voltage and maintaining voltage are set as 90 V and 21 V;number of the coil turns is 30 N;air gap is determined as 0.6 mm;the opening and closing time are respectively 0.98 ms and 0.8 ms. This paper can be used as a reference for the design of the solenoid valve.

正负脉冲电压驱动的电磁螺纹插装阀动态特性分析

提出了一种基于PWM技术的正负脉冲电压控制策略,用于提高锥阀式电磁螺纹插装阀启闭动态响应速度,使其满足数字液压技术的要求。在分析电磁螺纹插装阀结构和工作原理基础上,建立了电磁螺纹插装阀的数学模型,并在AMESim软件中搭建电磁螺纹插装阀及其测试系统的多物理场耦合建模,研究不同正负脉冲电压持续时间条件下电磁螺纹插装阀线圈电流、阀芯位移、电磁力的变化规律,确定了电磁螺纹插装阀响应速度最快时正负脉冲电压控制策略的最优控制参数。利用半实物仿真系统搭建SCV硬件在环测试实验台,对所提正负脉冲控制策略进行验证。实验表明,与常规电压控制策略相比,当正负脉冲电压控制策略中正负脉冲电压持续时间都为10 ms时,电磁螺纹插装阀的开启时间由30 ms缩短到13.5 ms,其关闭时间由139 ms缩短到14 ms。研究结果为电磁螺纹插装阀的高响应化和数字液压技术的发展提供参考。

汽车发动机电控燃油系统电磁阀特性仿真

为了定量分析电磁阀参数对其动态响应特性的影响,基于电磁理论建立了电磁阀的数学模型,并使用仿真模型开展了仿真研究。模拟了电磁阀在恒电压驱动下的动态响应过程,研究了驱动电压、初始气隙、弹簧预紧力和线圈匝数四个参数对电磁阀动态特性的影响,给出了电磁阀在不同参数下的位移变化曲线,从理论上确定了电磁阀的动态响应特性与其结构参数和控制参数之间的关系,为电磁阀的参数匹配及电控燃油系统的优化设计提供了依据。

电磁阀异步启闭的PWM喷雾系统设计与试验

PWM变量喷雾是国内外精准农业领域的研究热点,但PWM变量喷雾过程中电磁阀的快速启闭在管路内易形成压力脉冲,致使喷头喷雾压力发生变化,导致喷雾质量下降。为了降低压力脉冲,设计了一种相邻电磁阀异步启闭的PWM喷雾系统,由移动底盘、药箱、隔膜泵、稳压罐、PWM控制器、电磁阀及压力表等组成,通过延时控制,实现电磁阀异步启闭。在室内无风环境条件下,探究了喷雾系统电磁阀前管路内压力波动特性和沉积量分布均匀性。试验表明:与电磁阀同步启闭的PWM喷雾系统相比,电磁阀异步启闭可有效降低管路内压力峰值,不同PWM频率工况条件下,50%占空比时降幅最大,降幅最高为14%;20Hz频率条件下,异步启闭PWM喷雾的沉积量分布均匀性变异系数略高于常规连续喷雾,但均小于15%。上述结果符合喷杆喷雾机技术性能国家标准。

隔膜式电磁阀内部流场数值模型构建与流动特性分析

基于k-ε(k为湍流动能,ε为湍流耗散率)湍流模型,以进口质量流量、出口静压为数值计算条件,建立了隔膜阀内部流场的数值模拟模型,并对模型的精度进行了试验验证。在此基础上,应用该模型分析了不同进口流量(2.787~33.273 kg/s)条件下阀体内部流动特性及压力场分布规律,并建立了进口流量与阀体水头损失的精确数量关系。结果表明:(1)数值模拟能较好的预测不同流量条件下阀体的水头损失,在进口流量分别为5.546、11.091和16.637 kg/s时,试验与数值模拟相对误差仅为-6.433%、4.619%和7.264%。(2)在进口流量恒定的条件下,从进口至出口,流道内的静压总体沿程呈减小趋势,在阀体内部由于阀坎的阻挡造成流道收缩以及水流撞击隔膜产生折流而出现较大的静压变化梯度。(3)水流在经过阀坎上的窄流道后,在阀体下游形成明显的空化区,伴随着有一定的回流现象,阀体下游的空化区主要出现在距出口1/3流体域处,随着进口流量的增大,阀体下游的涡流更加剧烈,回流现象更为显著,但回流区的范围并未显著增加。(4)在模型精度验证的基础上,应用该模型进一步分析了18种进口流量条件下阀体内部流动特性及压力场分布规律,并建立了进口质量流量Q与阀体水头损失?P的数量关系,当进口质量流量Q从2.787~15.428 kg/s,雷诺数从37927~215984时的拟合方程为?P=2076.31Q-7567.49,R^(2)=0.964;进口质量流量从17.141~33.273 kg/s,雷诺数从240097~467009时的拟合方程为?P=5688.02Q-67317.39,R^(2)=0.993,为灌溉管网水力计算提供了参考依据。

基于PLC的变量喷雾系统的设计与试验

精准农业是农业生产的发展方向,故根据精准农业中变量喷雾技术的发展需求,对变量喷雾技术进行研究。在此,主要介绍了一种基于可编程逻辑控制器(Programmable Logic Controller,PLC)的变量喷雾系统,通过试验验证该变量喷雾系统的变量性能。变量喷雾系统主要由PLC、触摸屏(Touch Panel Monitor)、电磁阀、药水泵、压力表及电源模块等组成,使用触摸屏通过RS232通讯给PLC发送变量信号,PLC接收到信号后调节电磁阀的开度,达到变量喷雾的目的。通过在3个不同管路压力、10个不同电磁阀开度的试验,建立管路压力、电磁阀开度和喷头喷雾量的模型参数。试验结果表明:喷雾系统有较好的变量能力,在同一压力、不同开度条件下的最大变量能力为6.77,在不同压力、不同开度工作条件下最大变量能力为9.91。在不同压力下,分析并验证了电磁阀开度与喷雾量之间函数关系,曲线拟合结果表明:利用线性函数、指数函数、多项式函数拟合电磁阀开度和喷雾量,决定系数均大于0.9,最大为0.9998。相对误差分析结果表明:利用指数函数和多项式函数拟合的平均相对误差均在4%以内,可为变量喷雾机的设计与应用提供技术与数据支撑。

核电主蒸汽阀站中电磁先导阀的动态响应仿真研究

针对核电主蒸汽阀站中关键部件之一——大气释放阀前置隔离阀在实际工况中常出现响应超时的问题,采用数值仿真软件Fluent中的动网格以及用户自定义函数技术,对控制其启闭过程的电磁先导阀动态响应过程进行了研究。首先,研究了电磁先导阀中先导结构的动态响应过程以及阀杆的受力情况;然后,研究了电磁先导阀中主阀的动态响应过程以及主阀泄压时阀内的压力和速度分布情况;最后,综合两个动态过程,分析了电磁先导阀整阀的运动时间。研究结果表明,电磁先导阀的运动时间为8.5 ms,其中先导结构的运动时间占比较小,85%的时间集中在电磁先导阀主阀动作过程。该研究结果可对前置隔离阀响应时间的优化提供参考。

基于FirmSys平台的优选模块故障分析与防护研究

针对核电站优选模块故障的根本原因,进行深入的理论与工程应用分析。基于电磁兼容(EMC)防护原理及要求,开展干扰源及关键特性识别技术研究。采用继电器隔离的方案防护电磁干扰。增加续流二极管方案防护反向电动势。经试验验证,继电器隔离方案可满足优选模块反馈通道的电磁干扰防护要求,而续流二极管方案可满足优选模块输出通道的反向电动势防护要求。该研究提升了安全级信号采集回路的抗电磁干扰能力、建立了基于EMC试验的强干扰测试技术方案,从而有效解决了在实验室内无法准确产生瞬态干扰的难题。

双向复位高速开关电磁阀动态响应特性仿真研究

高速开关电磁阀作为典型的伺服液压系统执行元件,逐渐成为高精密液压系统的核心部件之一。针对双复位弹簧式高速开关电磁阀的动态响应特性开展研究,建立高速开关电磁阀的多场耦合动力学模型,系统研究了高速开关电磁阀阀芯内径、弹簧刚度、线圈线径、工作温度、控制频率及占空比等对高速开关电磁阀阀芯所受到的电磁力和阀芯运动位移的影响,得到了高速开关电磁阀的优化设计参数,为进一步研制响应速度快、性能稳定、流量及承压范围大、环境适应性强的高速开关电磁阀奠定了一定的理论基础。

常开燃油电磁阀高低温流场特性

常开燃油电磁阀作为共轨燃油喷射系统的关键控制部件,研究启闭两种工作过程中,温度的高低变化对电磁阀流场特性的影响规律,在燃油阀材料的选择和结构优化设计上具有重要意义。首先,对常开燃油电磁阀的工作原理进行分析,并且利用Workbench建立热固耦合有限元仿真模型。其次,深入研究该燃油阀受高低温影响的形变规律,以及阀芯在开启和关闭过程中所受液压力的变化规律。最后,采用Fluent流场仿真软件,研究阀口不同开度下,温度对燃油阀流量-压差特性的影响规律。结果表明,温度对阀口形变影响较小;在启闭两种工作过程中,阀芯所受液压力均呈先增加再减小的变化规律;在同一条件下,燃油介质温度越低压差越大。对燃油电磁阀高低温的仿真分析,在常开燃油电磁阀的初始设计阶段,具有重要实践意义。

衔铁偏心对高速电磁阀全工况电磁力的影响

高速电磁阀(HSV)是电控燃油喷射系统的关键部件,其衔铁偏心作用是影响高速电磁阀静、动态特性的重要因素.为了揭示高速电磁阀衔铁偏心作用对其全工况电磁力的影响规律,结合试验和数值模拟方法,建立了高速电磁阀有限元仿真模型,并通过与试验电磁力对比验证了其精度,最大误差为4.8%;分析了衔铁中心偏移和偏转及其交互作用对高速电磁阀电磁力的影响.结果表明:随着衔铁中心偏移率增大,轴向电磁力逐渐变小,而径向电磁力逐渐增大,但总体对电磁力的影响不显著;随着衔铁中心偏转角增大,轴向电磁力近似呈线性下降,轴向电磁力最大降低率为59.5%,而径向电磁力虽然逐渐增大,但增幅不明显;衔铁中心偏移与绕偏移方向偏转交互作用对轴向电磁力的影响最显著,全工况下该交互因子与轴向电磁力的相关系数绝对值最小为0.471,最大为0.624.