煤堆自燃发火对落煤筒筒壁温度场及温度应力的影响研究

Study on the influence of stored coal spontaneous combustion on temperature field and thermal stress of the wall of coal falling silo

堆煤自燃发火产生的高温会对落煤筒筒壁产生危害,给整个结构带来较大的安全隐患。通过分析煤堆的自热层和自燃层厚度,确定了落煤筒筒壁结构温度场和温度应力的重点研究区域。以陕西益东矿落煤筒为研究对象,采用硅胶加热带来模拟煤堆自燃的热量,对几何缩尺为1∶40的落煤筒模型进行试验研究,确定了温度场对落煤筒筒壁温度应力的影响规律。鉴于试验仪器的制约和安全性考虑,针对试验温度远低于原煤自燃发火温度的不足,以热传导方程为理论基础,利用ANSYS软件的热分析功能,将煤堆自燃产生的高温作用于外堆煤角360°和210°堆煤工况下落煤筒筒壁,进行热传导计算,得出了煤堆高温对煤筒筒壁温度场、温度应力的影响规律以及温度场、温度应力在筒壁中的分布规律,提出了施工中的预防措施。

The high temperature from spontaneous combustion of stored coal would cause harm to the wall of coal falling silo and bring greater security risks to the whole structure.The key research area of temperature field and thermal stress of the wall of coal falling silo was determined by analyzing the thickness of the self-heating layer and the spontaneous combustion layer of the stored coal.Taking the coal falling silo of Yidong Mine in Shaanxi Province as the research object,the heat of stored coal spontaneous combustion was simulated by the silicone heating belt and the experimental study was constructed on the model of coal falling silo with geometric scale of 1:40 and the influence law of temperature field on the thermal stress of the wall of coal falling silo was determined.Due to the restriction of the test instrument and safety considerations,the test temperature was far lower than the spontaneous combustion temperature of stored coal.Based on the theory of heat conduction,using the thermal analysis function of ANSYS,the high temperature from spontaneous combustion of stored coal was applied to the wall of coal falling silo under the condition of stored coal at 360°and 270°and the heat conduction of the wall of coal falling silo was calculated.The influence law of high temperature from spontaneous combustion on the temperature field and thermal stress of the wall of coal falling silo and the distribution law of temperature field and thermal stress in the wall of coal falling silo were obtained and the preventive measures in construction were proposed.