Numerical Simulation And Experimental Study On Temperature Field In Storage Silos

Silo coal storage due to its own physical and chemical properties of coal,coupled with the storage silo "chimney effect",the coal in a limited confined space,the heat did not spread,leading to spontaneous combustion or explosion of coal oxidation,affecting the power plant Safe and effective operation.Studying the law of temperature distribution of loose coal in coal storage silos is the prerequisite for solving the problem of spontaneous combustion of loose coal.In this paper,a combination of numerical simulation and experimental research methods,first of all,the use of hot wire method to measure the thermal conductivity of loose coal,and numerical simulation and thermal conductivity measurement process to verify the rationality of the experimental data;set up a small coal storage laboratory Warehouse and large coal storage silos for temperature field test,the finite element software ANSYS was used to establish the finite element model of small coal storage silos and large coal storage silos.By calculating the model load,the coal temperature in coal silos Field distribution law,the test results and numerical simulation results were compared,the temperature distribution under different high-temperature heat source conditions and the factors that affect the temperature distribution.Combining the numerical simulation and the hot wire method for measuring the thermal conductivity can know the temperature distribution while deriving the thermal conductivity,which has reference significance for the accurate fitting of the experimental data and the size design of the experimental device.The results of temperature field test and numerical simulation show that the distribution of temperature field of loose coal in coal storage silos is related to the strength,time and distance of heat source.The intensity of heat source is more obvious,which indicates that monitoring Low temperature heat source has some difficulties;the strength of convection heat transfer caused by floating force is related to the size of coal storage silo,which can not be neglected in practical problems analysis,and the direction of buoyancy is vertical upward;Coal The smaller the sample size,the smaller the size of the coal storage silo,the shorter the spontaneous firing period.When the heating heat flux density is 4520 W / m2,the maximum measuring point temperature reaches 40 ℃ when the heating temperature is 150 min.When the heating heat flux density is 3876 W / m2,the maximum measuring temperature Point temperature reached 53 ℃,natural firing period was significantly longer.Understand the distribution of temperature field in coal storage silos,can accurately locate the high temperature heat source area to prevent spontaneous combustion of loose coal to ensure the efficient operation of power plants,while the temperature field distribution can also provide parameters for the design of post-inertization protection device basis.