LN_(2)/CO_(2)复合制干冰对松散煤体降温特性  

Cooling characteristics of LN_(2)/CO_(2) composite preparation of dry ice on loose coal

作　　者：张铎 孙艺 赵得福 冶平 文虎 张首石[1,2] ZHANG Duo;SUN Yi;ZHAO Defu;YE Ping;WEN Hu;ZHANG Shoushi(College of Safety Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Key Laboratory of Western Mine and Hazard Prevention,Ministry of Education,Xi’an University of Science and Technology,Xi’an 710054,China;Qinghai Energy Development(Group)Co.,Ltd.,Xining 810000,China;Qinghai Energy Yuca Co.,Ltd.,Haixi 817000,China)

机构地区：[1]西安科技大学安全科学与工程学院,陕西西安710054 [2]西安科技大学西部矿井开采及灾害防治教育部重点实验室,陕西西安710054 [3]青海省能源发展(集团)有限责任公司,青海西宁810000 [4]青海能源鱼卡有限责任公司,青海海西817000

出　　处：《西安科技大学学报》2024年第1期23-33,共11页Journal of Xi’an University of Science and Technology

基　　金：国家自然科学基金项目(51904234,52274229);陕西省自然科学基础研究计划(2021JC-48);榆林国家高新技术产业开发区科技计划项目(ZD-2021-05)。

摘　　要：为研究LN_(2)/CO_(2)复合制备干冰对松散煤体的降温特性并实现最优复配,利用自主设计搭建的可视化凝华试验台,系统分析LN_(2)和CO_(2)在不同注输比下对管道内温度、压力及干冰成核效果的影响;以可视化凝华试验为基础,设计搭建松散煤体降温试验台,系统分析不同注输比下LN_(2)和CO_(2)在注输停注过程的传热特征及对松散煤体温度场的抑温效果。结果表明:CO_(2)凝华需要LN_(2)提供足够过冷度,当CO_(2)注输量不变,增大LN_(2)/CO_(2)注输比,管路内制冷温度降低,压力升高,LN_(2)和CO_(2)的混合流体换热效率增加,凝华发生时间提前;相变潜热引起的冷却能量具有时间-空间特征,压注阶段,箱体内各测点温度随时间持续下降,平面一降温速率明显快于平面二,低温区域逐渐呈锥形扩大;回温阶段干冰颗粒在煤层堆积,持续发挥降温惰化作用,注入口附近煤体与高温煤体之间存在温差进行换热,箱体中部温度逐渐升高、四周温度逐渐降低直至平衡;当LN_(2)、CO_(2)注输比为4∶1时,持续降温能力呈现较高水平。研究成果促进了干冰相变冷却技术在矿井防灭火领域的深入应用。In order to study the cooling characteristics of LN_(2)/CO_(2) composite preparation of dry ice on loose coal and achieve the optimal combination,the visualized condensation test platform designed and built by ourselves was used to systematically analyze the effects of LN_(2) and CO_(2) on the temperature,pressure and nucleation effect of dry ice in the pipeline under different injection and delivery ratios.Based on the visual condensation test,the loose coal cooling test platform was designed and built to systematically analyze the heat transfer characteristics of LN_(2) and CO_(2) during the injection stop process and the temperature inhibition effect on the loose coal temperature field under different injection and delivery ratios.The results show that LN_(2) is required to provide sufficient undercooling degree for CO_(2) condensation,when the CO_(2) injection and delivery volume remains unchanged,the LN_(2)/CO_(2)injection and delivery ratio increases,the cooling temperature in the pipeline decreases,the pressure increases,the heat transfer efficiency of the mixed fluid of LN_(2) and CO_(2) increases,and the time of condensation is advanced.The cooling energy caused by the latent heat of phase transition has the characteristics of time-space;during the injection stage,the temperature of each measuring point in the box continues to decrease with time,the cooling rate of Plane 1 is obviously faster than that of Plane 2,and the low temperature area gradually expands in a conical shape.The dry ice particles accumulate in the coal seam in the recuperation stage,and continue to play the role of cooling inerting.There is a temperature difference between the coal body near the injection port and the high temperature coal body for heat exchange,and the temperature in the middle of the box gradually increases,and the temperature around the box gradually decreases until equilibrium.When the LN_(2)/CO_(2) injection/delivery ratio was 4∶1,the continuous cooling capacity shows a higher level.The research results promote

关 键 词：LN_(2)/CO_(2) 注输比 干冰 相变 灭火性能 

分 类 号：TD75[矿业工程—矿井通风与安全]