PWM间歇喷雾变量喷施系统中压力波动的形成、衰减及耦合机理研究

项目名称： PWM间歇喷雾变量喷施系统中压力波动的形成、衰减及耦合机理研究

项目编号： No.51275215

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 机械、仪表工业

项目作者： 魏新华

作者单位： 江苏大学

项目金额： 80万元

中文摘要： 变量喷施是施药技术的重要发展方向，PWM电磁阀控制间歇喷雾是变量喷施控制的主要方式，但压力波动影响了其雾化特性和喷雾流量控制精度的提高。本项目以PWM间歇喷雾变量喷施系统中的压力波动为研究对象，采用数值模拟、建模仿真和试验测试相结合的方法，通过对高速开关电磁阀、隔膜泵稳压气室、比例溢流阀和药液管路的内部流场的动态特性分析，建立各液压元件及整个PWM变量喷施系统的数学模型；对其压力波动特性进行仿真，揭示高速开关电磁阀启闭过程中压力冲击的形成过程，给出比例溢流阀对压力波动的响应特性，探明稳压气室对隔膜泵周期性压力脉动和管路压力波动的衰减机理和频率响应特性，揭示压力波动在药液管路中的传播和叠加耦合机理，并探明各液压元件主要结构和工作参数以及液压元件之间的参数匹配对压力波动的影响规律。从而为PWM间歇喷雾变量喷施系统中的压力波动稳定控制奠定理论基础，为施药机械的数字化仿真和优化设计提供理论支撑。

中文关键词： 变量喷施；脉宽调制；压力波动；稳定控制；CFD仿真分析

英文摘要： Variable rate application is an important development direction for agricultural chemicals application technology. Blended-pulse intermittently spraying flow control method is the primary method for variable rate application control. But improvement of spray pattern and flow control precision was impeded by its pressure fluctuations. This project will address the pressure fluctuation problem in the blended-pulse variable rate application system. Numerical computation method, modelling and simulation method and experimental testing method will be combined in the study of this project. Mathematical models of fast acting solenoid valve, diaphragm pump and its damper, proportional overflow valve, pipelines and the blended-pulse variable rate application system will be established by dynamic characteristics analysis of their internal flow field. Emerging mechanism of pressure fluctuation will be revealed by simulation analysis of opening and closing process of the fast acting solenoid valve. Frequency response characteristic of the damper to the pressure fluctuation will be deduced by simulation analysis of the diaphragm pump and its damper. Response characteristics of the proportional overflow valve to the pressure fluctuation will be deduced by simulation analysis. Mechanisn of spreading and coupling of the pressur

英文关键词： variable rate application；pulse width modulation；pressure fluctuation；stable control；CFD simulation