Acoustic monitoring method for temperature distribution of stored grain

Abstract

The present invention is an acoustic monitoring method for the temperature distribution of stored grains. Sound wave emitters / receivers are arranged around the measured area, and the sound waves emitted by any emitter / receiver can be included by itself through the air channel in the gap between grain particles. of all transmit / receive receivers. Sequentially open and close each transmitter / receiver within a detection cycle, and measure the propagation time of the sound wave along each effective propagation path in the grain; divide the measured area into a spatial grid, and use the obtained sound wave propagation time and three-dimensional sound velocity field to reconstruct The algorithm and the relationship between the speed of sound and temperature in the grain, reconstruct a temperature for each grid and assign the grid center, and then use the interpolation calculation method to obtain the temperature distribution of the entire measured area; it can significantly improve the spatial resolution of temperature monitoring of stored grain, Timely discover hot spots in grain storage caused by mildew, insect pests, water leakage on the roof of the warehouse, etc., avoid large-scale grain loss, and do not affect the operation in the warehouse. It is suitable for online monitoring of the temperature distribution of bulk grain in the grain warehouse.

Description

Technical field: [0001] The invention belongs to the technical field of monitoring the temperature distribution of stored grains, and mainly relates to a method for realizing non-contact measurement of the temperature distribution of stored grains by using an acoustic temperature field detection technology. Background technique: [0002] Safe storage of grain is a worldwide problem. According to the survey and statistics of the Food and Agriculture Organization of the United Nations, the annual loss of grain mildew and insect damage in the world is 8% of the grain output. my country's public grain is now all stored in national or local warehouses. The temperature of stored grain is an important indicator for judging the state of stored grain. Mildew, insect damage, and moisture anomalies that occur during grain storage will be reflected in grain temperature changes, that is, the appearance of hot spots. Contact temperature measurement is used for temperature monitoring of g...

AI Technical Summary

Problems solved by technology

Grain is a poor conductor of heat. Since it is impossible to install a large number of temperature measuring cables in the granary, and the contact temperature sensor can only obtain the temperature of the "point" where the sensor is located, if the hot spot does not happen to happen near a certain temperature measuring point , it will not be discovered, and local mildew or insect damage may cause large-scale grain damage and cause serious losses if measures are not taken in time

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