浮地式粮食水分在线检测装置设计与试验  

Design and Test of Grain Moisture Online Measuring System Based on Floating Ground Capacitance

作　　者：麦智炜[1] 李长友[1] 徐凤英[1] 方壮东[1] 

机构地区：[1]华南农业大学工程学院,广州510642

出　　处：《农业机械学报》2014年第10期207-213,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：高等学校博士学科点专项科研基金资助项目(20114404110021;20060564003)

摘　　要：基于非接触式平行极板浮地电容测量原理,设计了一种适用于恶劣环境的电容式粮食水分检测装置,结合静态批次测量法,以提高测量的重复精度;设计了定位充料器,消除了因堆积方式不同引起空隙率变化对测量造成的误差。采用无线通信技术,实现传感器与计算机客户端的实时数据传输,克服了干燥现场恶劣工况对数据信号传输的影响,适用于干燥机干燥过程中的粮食水分在线实时检测。在连续式干燥机上,在线检测玉米的试验结果显示,温度在15～50℃,相对湿度在80%～100%,玉米含水率范围在14%～21%动态变化的条件下,在线检测结果与国标规定的烘箱法测量相比,最大偏差小于±0.4%。采用定位充料,批次稳态测量,无线通讯保证了在线检测的精度和可靠性,为实现粮食干燥过程自适应控制提供了含水率在线检测技术手段。A new type of capacitive grain moisture on-line measuring device was designed based on the measuring principle of non-contact parallel plate floating capacitor,which was suitable to continuous dryer under severe environment.The static batching measurement was used to improve the repeated accuracy of the measurement.Positioned filling device was designed to eliminate the measuring error caused by the variation of porosity and different way of filling.Wireless communication technology was adopted to achieve real-time data transmission from client sensors to computer and overcome the poor drying conditions,which could affect data transmission.The relationship among moisture,temperature,and capacitance of corn was calibrated and the system was tested on a continuous dryer.The results showed that the correlation coefficient between results of oven method and results of online measuring system was 0.992,and the absolute error of measurement was less than ± 0.4%,while the working temperature was 15 ～ 50℃,relative humidity was 80% ～ 100%,drying temperature was 70℃,and the corn moisture content range was 14% ～ 21%.It proved that the online measuring system meet the design requirement of poor drying conditions.

关 键 词：粮食 水分 在线检测 设计 试验 

分 类 号：S237[农业科学—农业机械化工程]