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Grain temperature is one of the most important factors that affect the safety of grain storage. In order to reveal the distribution rule of grain storage temperature field in semi-underground double-storey squat silos(SUDSSS), the mathematical analysis models of the grain piles of the ground squat silo and the underground silo are established respectively in this paper, and the validity of the models is verified by the field test results. A numerical model of the SUDSSS was established. Through numerical analysis, the temperature field variation rule of the grain pile during the 1-year static storage of the SUDSSS after low-temperature grain storage was acquired by numerical analysis. The research demonstrates that the grain temperature within 2 m of the above-ground part of the SUDSSS close to the silo wall varies significantly because of the influence of the outside air temperature, and the temperature from 10.62 to 27.37 °C. The grain temperature in the underground part is in a quasi-low temperature state all the year round, and the average temperature does not exceed 17 &#176C of the temperature in the underground constant temperature zone. At the beginning of the winter, a heat accumulation area will be formed in the upper storey of the ground between 1 - 3 m from the warehouse wall in a short period of time, leading to a large temperature difference in the grain pile near the warehouse wall, and then the temperature in the peripheral area will slowly decrease, forming a 'hot core and cold skin', and the thermal insulation measures of the silo wall can effectively reduce the influence of temperature on the grain temperature. The highest grain temperature in the upper storey in summer is about 3.86 °, lower than that of the shallow silo without thermal insulation. The research results can provide technical support for the popularization and application of the SUDSSS. [ABSTRACT FROM AUTHOR]

The growth cycle of tellurium zinc cadmium crystals is long and the growth system is complex. When using vertical Bridgman or vertical gradient freezing methods to grow tellurium zinc cadmium (CdZnTe) crystal materials, the growth process is often difficult to observe intuitively, and there is no corresponding means to detect the temperature field inside the crystals, which brings inconvenience to improve the crystal growth process. In this paper, numerical simulation software is used to analyze the influences of furnace air convection on the temperature field of CdZnTe crystal growth. By opening holes at the top and bottom of furnace, gas exchanging occurs between the inside and outside of the furnace, thereby regulates the convection behaviors. Before opening holes, the convection rate is slow (only 10-5 m/s), forming stable convection cells; after opening holes, the convection rate significantly increases (0.25 - 0.90 m/s), and the convection state changes to laminar flow. Through controlling the aperture size (20 - 40 mm) in the model, the laminar flow rate can be effectively regulated. At the same temperature setting, when the flow rate increases from 0.25 m/s to 0.90 m/s, the temperature gradient will increase from 0.5 K/mm to 1.1 K/mm. Furthermore, experimental work is applied on real furnace, the change of temperature filed before and after opening holes were studied. The experimental results of temperature gradient is accord with the simulating results. It is also found that under laminar flow state, increasing convection rate may improve the stability of temperature field. The increase of temperature gradient and the improvement of stability in the temperature field will be beneficial for the preparation of high-quality CdZnTe crystals. [ABSTRACT FROM AUTHOR]