Research on the temperature field of grain piles in underground grain silos lined with plastic

To investigate the temperature change in grain piles during underground grain storage, this study considers high-moisture grain, and uses a combination of experiments and numerical simulation to study the change in the temperature field in the underground bin during the static storage and mechanical ventilation phases. The results show that during the static storage stage, grain respiration is strong. The grain pile first begins to heat up at the bottom and gradually forms a high-temperature heat core; in the mechanical ventilation stage, the grain pile first cools down from the air outlet, and then gradually spreads to the entire silo. Inside, the study found that the diffusion path is related to the air duct setting. After being ventilated for 10 hr, the grain pile temperature in the test silo fell below 10°C from the middle to the bottom of the silo, and only reached 15°C above the return air outlet near the grain-loading line. An increase in air supply accelerates the temperature decrease in the grain pile; the difference in the initial state of the grain pile has little effect on the cooling effect of mechanical ventilation. In the experiment and simulation, the mechanical ventilation adopts a uniform air supply method, which has a significant effect on reducing the grain pile temperature in the silo. Practical Applications In this study, a test platform is established for an underground silo lined with plastic. By monitoring the temperature in the test silo, the dynamic temperature changes in the grain pile can be analyzed, and the results are compared with the numerical simulation results to verify the model reliability. The temperature field simulation of grain piles under different conditions lays the foundation, and at the same time provides a basis for formulating relevant measures to achieve safe grain storage.