论文部分内容阅读
为了解煤堆自燃过程中的温度场变化、能量迁移和氧气流动情况,基于煤堆的颗粒特性以PFC3D为模拟平台,借助其热力耦合模型,模拟了煤堆的自燃氧化过程,及该过程中的温度场变化和能量迁移;使用极小颗粒模拟氧气的流动及其与煤的反应,并通过FISH实现该过程。结果表明:随模拟时间延长,温度场高温区向煤堆坡面边界水平移动;能量迁移主要发生在靠近低温区的区域,且不同温区交界处迁移最多;高温区移动是由于氧化需氧量的变化、造成对氧的“抽吸”作用而产生的;煤堆内氧颗粒的流动可分为稳定区、杂乱区、微弱区,随着“抽吸”作用的增加,稳定区减小,杂乱区增加,微弱区增加。模拟计算至70 d,煤堆出现大范围高温区域并产生自燃,此时最高温度为362.1 K。
In order to understand the changes of temperature field, energy migration and oxygen flow in coal spontaneous combustion process, PFC3D was used as a simulation platform to simulate the spontaneous combustion process of coal piles based on the particle characteristics of coal piles. Temperature field changes and energy migration; the use of very small particles to simulate the flow of oxygen and its reaction with coal, and the process is accomplished by FISH. The results show that as the simulation time prolongs, the temperature field moves to the boundary of the coal pile slope horizontally. The energy migration mainly occurs in the area close to the low temperature area and the migration occurs at the junction of the different temperature areas. The movement in the high temperature area is due to the oxidation oxygen demand , Resulting in the “suction” effect on oxygen. The flow of oxygen particles in the coal heap can be divided into stable zone, disorder zone and weak zone, with the increase of “pumping” effect and stability The area is reduced, the messy area is increased, and the weak area is increased. After 70 days of simulation, a large area of high temperature appeared in the coal pile and spontaneous combustion occurred. At this time, the maximum temperature was 362.1 K.