Authors

Abstract

To enable the accurate detection of grain moisture content and improve the efficiency of the drying process, a parallel-plate moisture content detection device (PPMCDD) was developed in this study. Firstly, the detection principle and influencing factors of this device are analyzed. Then the effects of three key factors as distance, thickness, relative area on the accuracy of the device were determined through simulation, and the optimal combination of parameters was obtained through analysis of variance of a regression model and response surface methodology. Finally, a simple test bench is built to verify the effectiveness of PPMCDD by comparative experiment. Through simulation and response surface analysis, the optimal combination parameters are as follows: thickness =1 mm, pacing =19.54 mm, relative area =4023.17 mm2, corresponding to the measured capacitance value of 37.676 pF. By comparative experimental analysis, it is found that the maximal relative error of the moisture content detection device evaluated in this study was 1.58%. The detection error is small, and the device exhibits high accuracy and stability and meets the design requirement.

Abstract in Chinese

为了提高烘干机谷物含水率的检测精度和干燥过程的效率，本研究开发了一种基于电容法的平行板式含水率检测装置(PPMCDD)。首先，根据电容检测原理和影响因素进行了分析，并对平行极板模型进行了初步设计；然后通过仿真确定了距离、厚度、相对面积三个关键因素对装置精度的影响，并通过回归模型方差分析和响应面法得到最佳参数组合；最后通过对比实验验证PPMCDD的有效性。通过仿真和响应面分析得到最佳的组合参数为：厚度=1mm，间距=19.54mm，相对面积=4023.17mm2，对应实测电容值为37.676pF；并且通过对比实验分析，本研究评估的含水率检测装置的最大相对误差为1.58%。PPMCDD检测误差小，具有较高的检测精度及稳定性，满足设计要求。