冷凝段翅片类型对热管抑制煤自燃的降温效应影响研究

Study on the influence of fin types in condensation section on the cooling effect of the heat pipe to suppress coal spontaneous combustion

为了研究热管冷凝段翅片类型对抑制煤自燃的降温效应的影响,实验研究了将热管插入加热煤堆后的降温效应。采用碳钢-水重力热管,在温度为75~20℃内,研究了不同冷凝段结构的热管对煤堆内部温度的影响,探讨了热管对煤堆内部温度场的影响规律。研究结果表明:相同时间段内弯曲垂直翅片热管作用下高温煤体在50℃前后降温速率衰减幅度为64.98%,大于无翅片、垂直翅片和圆形翅片3种热管作用下的煤体降温速率衰减幅度,即弯曲垂直翅片热管移热降温效果最好;弯曲垂直翅片热管对煤堆内部3个水平面温度场的影响有明显差异,在下水平面主要为热管工质相变移热,在中水平面及上水平面主要为热管管壁移热。

In order to study the influence of fin types in condensation section of the heat pipe on the cooling effect of suppressing coal spontaneous combustion,the cooling effect of the heat pipe inserted into the heated coal pile was studied experimentally.By using carbon steel-water gravity heat pipe,the influence of heat pipes with different condensation sections on the internal temperature of coal piles were studied in the temperature range of 75℃to 20℃,the influence of heat pipe on the internal temperature field of coal piles was discussed.The research results show that under the influence of the heat pipe with curved vertical fin,the cooling rate attenuation of the high-temperature coal is 64.98%in the same period before and after 50℃,which is greater than that of other three kinds of heat pipes including without fin,with vertical fins or circular fins,it means the heat pipe with curved vertical fin has the best heat removal effect;the influence of the heat pipe with curved vertical fins on the temperature field of three horizontal planes in the coal pile is obviously different,at the lower level,the heat removal is mainly caused by the phase change of the heat pipe,and the heat transfer of the pipe wall is mainly at the middle level and the upper level.