具有压差反馈与控制功能的齿轮流量计研究

Research on the Gear Flowmeter with the Function of Feedback and Control of the Pressure Difference

针对传统齿轮流量计由于压差导致的泄漏及磨损问题,设计一套零压差、高精度的齿轮流量计流量测量系统。基于LVDT信号处理芯片AD698以及STM32F407VGT6型微控制器,完成LVDT信号处理、电源转换、电机驱动、通信接口等硬件电路设计,基于数字PID,开发电机转速跟随流量流速的控制算法及流量测量软件,搭建实现零压差测量的高精度流量测量平台。结果表明:具有压差反馈与控制功能的测量系统能有效调节进出口之间的压差,实现零压差测量,降低了流量计的内部泄漏,具有较高的测量精度。相对误差保持在0.5%以内,能够满足高精度流量测量要求。

For the problems of the leakage and abrasion caused by pressure difference of traditional gear flowmeter,a non-pressure-difference and high precision flow measuring system was designed.Based on the LVDT’s signal processor chip AD698 and STM32F407VGT6 microcontroller,the hardware circuits of processing the LVDT’s signal,power supply conversion,motor driving and communication interface and so on were designed.On the base of digital PID,the control algorithm of the motor speed following flow and the flow measuring system software were developed.The high precision experiment platform was set up to realize non-pressure-difference measurement.The results show that:the system with the functions of feedback and control of the pressure difference can adjust the pressure difference between the entrance and exit,non-pressure-difference measurement is realized,the inside leakage of the flowmeter is reduced,and it has high measuring accuracy.Its relative error is less than 0.5%,which can satisfy the requirement of high precision flow measuring.