The Research On Temperature And Moisture Content On-line Measuring System Of Moist Grain Drying Vehicle

The moist grains (grains with high moisture content) hold the great proportion in the Northeast and North China area. In the drying process of moist grains, temperature and moisture content are the most important targets of measurement and control. On-line measurement for the moisture content of moist grains is a technical problem to be solved urgently.This thesis thoroughly studies the moisture loss law and the electric conduction characteristic of grains under the conditions of high temperature, negative pressure and periodically rolling, successfully develops a temperature and moisture on-line measurement system of the moist grains drying vehicle, and provides technical equipment for the new type grains drying machine which conforms to the Chinese national condition. This thesis also puts forward a multi parameter information confusion model, uses multi variant regression analysis to find out the algorithm of information confusion, guarantees that the result of information confusion is real-time, effective and accurate, and overcomes the deficiency of information and inaccurateness which are caused by traditional method. Considering that temperature, humidity inside the drying machine, dispersity and aging of components make the circuit changed, this thesis presents a new self-calibration method which can make up the ineffectiveness of conventional auto calibration technique on over range and zero passage, and implement the calibration of the whole system including driving source of sensor and measuring signal path. This new type on-line measurement system has broad application prospect.The thesis consists of 6 chapters:The first chapter describes the great significance of measuring grain moisture content, the research background and the innovation of the paper.The second chapter introduces the principle, features and application situation of existing gains drying technologies and moisture measurement methods, as well as developing trend.The third chapter systematically describes composition of on-line measurement system for the moist grain drying vehicle, and the principle of temperature measurement and moisture measurement, then presents the designs of hardware and software in detail.The fourth chapter presents a multi parameter information confusion method...