Experimental Study On Heat Storage Distribution Characteristics And Heat Transfer Of Water-bearing Coal Pile

Although our country is emphasizing the adjustment of energy structure in recent years,coal is still the main energy in our country and can not be completely replaced in a short time.While promoting the development of our national economy,there are also many safety problems.The spontaneous combustion of coal storage pile is a severe test in the process of coal storage,transportation and safe production.At present,relevant scholars at home and abroad have put forward excavation extinguishing method,grouting,three-phase foam injection technology and other technical measures for spontaneous combustion of coal storage pile.These measures greatly reduce the probability of spontaneous combustion of coal and reduce the damage to the environment and economic losses caused by spontaneous combustion of coal.In view of the above research,the undergraduate research team put forward a device which is helpful to water absorption and heat storage and guided discharge.The device can effectively conduct the heat inside the coal storage pile without causing the loss of coal calorific value.In this paper,the heat transfer performance of the device,the radius of action and the heat transfer of the device under different arrangements at medium and high temperature heat source temperatures are measured.In this paper,the distribution of heat storage temperature field and the factors affecting coal spontaneous combustion are discussed.Then,at 50 °C and 100 °C,the insertion depth is 30 cm,40cm,50 cm and 60 cm.When the insertion angle is 30°,45°,60° and 90°,the cooling temperature of the high temperature heat source point,the cooling rate of the typical measuring point,the effective heat transfer radius of the device,and the heat removal amount are analyzed.The experimental results show that after the device is arranged,the temperature drop of the high temperature heat source point which can visually display the heat transfer and temperature drop performance of the device is obviously improved,and the cooling curve is fitted and analyzed.By analyzing the cooling amplitude and cooling rate of typical measuring points under different heat source temperatures and different arrangement modes of the device,the results show that the cooling rate is 60°>90°>45°>30° when the device is placed at a depth of 60 cm.At the temperature of the two heat sources,when the device is placed at a depth of 60 cm,the radius of heat transfer at different inclination angles is: 42.7 cm,42.3 cm,45.3 cm,43.6 cm and 43.2 cm,42.6 cm,44.3 cm,43.6 cm,the action radius is 60°>90°>30°>45°;at two heat source temperatures,when the device is placed at a depth of 60 cm,the heat removal at different inclination angles is: 806.7 k J,823.9 k J,864.1 k J,838.3 k J and 829.7.k J,841.1 k J,887.1 k J and 866.9 k J,heat removal 60°>90°>45°>30°.In summary,the arrangement of the device is 60 cm in depth and the effect of heat transfer at the angle of inclination of 60° is the best.Through the above research,the water absorption and heat storage guiding discharge device can be used as a reference for the prevention and control of spontaneous combustion of coal storage piles.