煤炭在储运过程中常出现自燃现象，其氧化分解产生的有害气体给储运场所生产安全造成极大威胁。灌浆、注氮、覆盖等方式对煤堆蓄热的治理效果并不显著，内部蓄热无法消除存在自燃隐患。热管具有两相冷却的热中转特性，可使煤堆蓄热迅速转移。结合实验和数值模拟研究，搭建煤堆-热管传热性能测试平台，建立煤堆-热管复合传热数值模型，探究热管作用下煤堆自热过程热量迁移特征。

采用热管性能测试平台，开展了毛细芯热管在煤堆的移热实验，得到了煤堆降温过程热量迁移规律。研究表明煤堆近热源测点具有较高的温度敏感性，热管作用下的煤堆降温速率依次为：上层＞中层＞底层；毛细芯热管的强化散热效应使煤堆峰值温度降幅达到130.6℃，峰值降温率达到46.93%。热管移热效应可划分为三个范围：敏感区（5~25 cm）、过渡区（25~35 cm）和稳态区（＞35 cm）。

建立了煤堆-热管传热数值模型，模拟了热管作用过程煤堆热量流动特征，并对不同热管参数下煤堆热迁移行为进行了量化对比，得到了煤堆内部热量迁移速率、温度场及自燃危险区（SCDZ）分布规律。在热管与煤体作用过程中，温度等值线向热端偏移，偏移速率v与△x呈反比，并围绕热管形成“鞍形”降温形态。标记测点的升温、降温趋势与实验结果具有共性，所建模型与输入参数适用性验证结果精度较高。

煤堆自燃危险区高度集中在迎、背风侧中下部。研究发现，热管倾角θ对煤堆热量迁移行为抑制作用差异性显著，当θ为60°时冷却效果达到最佳，煤堆自燃危险区完整性被破坏，高温区面积减少10.5589 m²，最大缩减速率约为0.176 m²/d；煤堆温度最高下降至10.5 K，冷却效率约为0.18 K/d，煤低温氧化时间延长。热管插入间距不大于1.5m时，煤堆整体温度控制在60℃以下，最高冷却速率为0.46 K/d，表明煤堆蓄热通过热管中转至外界，综合考虑防治效果及经济效益，热管间距应设置在1.0~1.5 m范围。研究结果为毛细芯热管在煤堆防灭火工程中的推广应用提供了基础参数。

Spontaneous combustion often occurs in openair coal storage during storage and transportation. The harmful gases and elements produced by the oxidative decomposition pose a great threat to the ecological environment and safe production of storage sites. The treatment effect of grouting, nitrogen injection, mulching on the thermal storage of coal piles is lack of significance, and the internal high temperature area cannot be eliminated, there are still hidden dangers of spontaneous combustion. Based on the heat conduction of the heat pipe and the fast heat transfer properties of the working medium phase change, the heat at the high temperature end can be quickly transferred to the outside of the heat source. This study applied experiments and numerical simulation research to explore the influence of capillary core heat pipes on the thermal migration behavior of coal piles through the coal pileheat pipe heat transfer performance test experimental system. Through statistical analysis of the experimental data, the conclusions are summarized as following:

Using the heat pipe performance test platform, the heat transfer experiment of capillary core heat pipe in the coal pile is carried out, and the temperature change characteristics during the cooling process of the coal pile are obtained. The findings elucidate that: the coal body near the heat source has high temperature sensitivity; the cooling rate of the coal pile under the intervention of the heat pipe is as upper layer> middle layer > bottom layer. The enhanced heat dissipation effect of the capillary core heat pipe reduces the maximum temperature of the coal pile to 130.6°C, and the cooling rate reaches 46.93%; Through the curve trend, the heat transfer process of the heat pipe can be divided into three ranges: the sensitive area (5~25 cm), the transition area (25~35 cm) and the steady state area (> 35 cm).

A numerical heat transfer model between coal pile and heat pipe is established to simulate the heat flow characteristics of the coal pile, and the heat transfer behavior of the coal pile under different heat pipe parameters is quantitatively compared. The heat transfer rate, temperature field and distribution law of high temperature danger zone (SCDZ) in the coal pile are obtained. During the interaction between the heat pipe and the loose coal body, the temperature contour of the coal pile shifts to the hot end, and the migration rate v is inversely proportional to △x, and finally presents a “saddle” shape. The heating and cooling trends of the marked measuring points are in common with the experimental results. The built model and input parameters are suitable for verification results with high accuracy.

The high temperature area of the coal pile is highly concentrated and tends to the middle and lower parts of the windward and leeward sides. The study found that significant differences in the inhibitory effect of heat pipe inclination on the heat transfer behavior of coal piles. The cooling effect reaches the best when θ is set to 60°, the integrity of the natural danger zone of the coal pile is destroyed to 10.5589 m², and the reduction rate is about 0.176 m²/day, the maximum temperature of the coal pile drops by 10.5 K, the cooling efficiency is about 0.18 K/d. In the scheme of this study, when the heat pipe insertion distance is not greater than 1.5 m, the overall temperature of the coal pile is below 60°C, and the maximum cooling rate is 0.46 K/d. These demonstrate that the heat stored in the coal pile is dissipated to the outside through the cyclic phase change of the heat pipe. Taking into account the prevention and control effect and economic benefits, the inclination angle of the heat pipes should be 60°, and the spacing should be set between 1.0~1.5 m. The results provide a theoretical basis for the popularization and application of capillary core heat pipe in coal pile fire-fighting engineering.

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