复合惰气浆液二氧化碳相变特征研究  

Study on phase transformation characteristics of carbon dioxide in composite inert gas slurry

作　　者：张辛亥 张首石[1,2] 窦凯 王凯 赵思琛 ZHANG Xinhai;ZHANG Shoushi;DOU Kai;WANG Kai;ZHAO Sichen(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)

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

出　　处：《煤矿安全》2022年第6期57-62,68,共7页Safety in Coal Mines

摘　　要：为改善我国矿井火灾现状,优化单一惰性气体灭火技术的不足,搭建了干冰制备系统与可视化CO_(2)相变特征测试实验台,在不同管型下制备了液氮与干冰颗粒的液-固两相混合物,并结合数值模拟探索了三相混合物体系的形成机理及CO_(2)的相变特征。干冰制备实验结果表明:当CO_(2)管路夹角增大时,凝华温度从168 K降低至157 K;干冰凝华量增加,颗粒在重力作用下沉积于可视化管路底部形成凝华覆盖层,凝华层厚度向管路上部扩散。通过模拟发现:随LN_(2)与CO_(2)支管夹角当30°增大至90°,流体流速从14.5 m/s相应增大至15.8 m/s,温度下降速率加快,管路底部干冰生成体积分数增大,与实验结果吻合。To improve the current situation of mine fire in China,and to optimize the deficiency of fire extinguishing technology of the single component inert gas,a dry ice preparation system and a visual test bench for CO_(2) phase transformation characteristics were set up.Based on different tube types experiments,the three-phase mixture were prepared,which were composed of liquid nitrogen and dry ice particles,the formation mechanism of three-phase was discussed and the phase transformation characteristics of CO_(2) was analyzed by numerical simulation.The result shows that as the included angle of CO_(2) pipeline increases,the desublimation temperature decreases from 168 K to 157 K,dry ice desublimation increases.Dry ice particles can be accumulated on the visual inner wall by gravity to form a coating,and its thickness showed a trend of extending to the upper part of the pipeline.The simulation result shows that as the angle between LN_(2) and CO_(2) branch pipe increases from 30° to 90°,the fluid flow rate increased from 14.5 m/s to 15.8 m/s,the temperature decrease-rating increased,and the volume fraction of dry ice at the bottom of the pipe increased,which was consistent with the experiment results.

关 键 词：深冷惰气浆液 凝华 相变 二氧化碳 矿井火灾 自燃 

分 类 号：TD752.2[矿业工程—矿井通风与安全]