The study of the distribution of temperature fields of wheat grain along the vertical levels and horizontal layers during storage in the elevator silo

Abstract

This article presents an analysis of the temperature fi elds caused by seasonal fluctuations in the temperature of the outside air on the surface of the walls of the silos and inside the outdoor silo located on the south side of the precast concrete elevator for the annual cycle from March 2018 to March 2019. The paper analyzes the data of grain temperature along the horizontal layers of the silo at the upper and lower levels and the distribution of temperature fields over the upper and lower levels of the silo during heating and cooling of the grain. A comparative analysis of the heating and cooling rates and the effect of temperature differences in the silo on moisture absorption processes in the grain mass during storage is carried out. During the statistical processing of the experimental data, the following trends were obtained: in the deep layers of the grain, when the grain is heated, the temperature is lower, and when the grain is cooled, the temperature is higher than in the nearwall layers. The rate of temperature change in the grain mass depends on the location of the grain at different levels and on the horizontal layer. The average cooling rates were lower than the grain heating rates, and during the annual cycle, heat accumulation in the grain mass stored in the silo is possible. The infl uence of thermal moisture conductivity on the change in the humidity regime in the silo is considered. The results for the annual cycle indicate a cyclical change in the relative humidity of the intergranular space and an increase in the relative humidity in the summer-autumn period (from May to November) above the optimal value recommended for long-term storage. To eliminate the risks of grain moisture, the need for periodic movement of grain from silo to silo during long-term storage is substantiated.