煤矿井下氮气阻化细水雾防灭火降温技术应用基础研究

Mine fire is one of the major disaster during coal mining production. And water mist is an efficient means of extinguishing fire and lowering temperature. In order to put out the fire in closed fire zone of the underground coal mine more efficiently, the author proposed a new technology which extinguishes fire and brings down temperature by using inhibitor and water mist with nitrogen . Water mist diffuses throughout the fire area with nitrogen as the carrier, which has a good effect on extinguishing fire and lowering temperature because of the cooling performance of water. This research intends to build a water mist preparation and experimental system. Meanwhile, it tries to find out the critical conditions of nitrogen-powered water mist atomization and the change regularity of the amount of nitrogen-powered water mist, as well as the change regularity of characteristic parameters of water mist and the critical conditions of the condensation of mist particle when the water mist is carried in a pipe .By using the mine fire simulation experiment system, this research studies the relationship between characteristic parameters of water mist and fire-extinguishing and cooling effect in the space of shaft and drift, and this research demonstrates the diffusion kinetics characteristics of water mist with the throttling effect of different wind speed and different angles of roadway or under the influence of fire ventilation pressure. The heat and mass transfer law between water mist and high-temperature fire environment is also inverstigated in this research. By using five holes probe and laser schlieren system, this research studies the kinetic characteristics of gas-liquid rotary jet in water mist generating device and the relationship between shock intensity and the flow rate of nitrogen,pipe diameter.Besidese,the effects of shock wave on the atomization is also studied.At last, this research reveals nitrogen-powered water mist preparation , transport and diffusion extinguishing characteristics in underground coal mine, and then puts forward the design and optimization principles of atomization device. So, it enriches the basic theory of this technology, promotes its developments and applications in future, and provides new technical means for mine fire control.

火灾是煤矿生产中的主要灾害，细水雾是一种高效的灭火降温手段。为更有效地治理井下封闭火区，申请者提出了氮气阻化细水雾防灭火降温技术，利用水的降温性能，以氮气为载体，使水雾充满火区，实现良好的灭火降温功能。本项目拟建细水雾实验系统，研究不同气、水流动参数条件下雾化的临界条件、产雾量变化规律、管道输运中水雾特征参数变化规律和雾粒凝结的临界条件；利用井巷火灾模拟实验系统，研究细水雾特征参数与井巷网络空间中灭火降温功效间的关系、不同风速与倾角巷道中节流效应或火风压影响下细水雾扩散动力学特性及其与高温火灾环境的热质交换规律；采用五孔探针和纹影仪，研究雾化装置内气液旋转射流的动力学特性、激波产生强度与氮气流速和喉管直径的关系及激波对雾化效果的影响。揭示氮气细水雾井下制备、输送和扩散灭火特性，提出雾化装置的设计与优化原理。研究成果将丰富本技术的基础理论，推动其发展和应用，为矿井火灾的治理提供新的技术手段。

针对细水雾防治矿井火灾方面的基础理论研究欠缺，本项目以实验室研究和工业试验为主要技术手段，系统地研究了煤矿井下氮气阻化细水雾防灭火的基础理论。在实验室构建综合实验系统，实验研究了气、水不同流动参数条件下所产生细水雾的特征参数、雾化的临界条件、产雾量的变化规律和雾粒凝结的条件；在实验室构建了氮气阻化细水雾灭火模拟试验台，实验研究了细水雾在井巷网络空间中的灭火降温功效和细水雾在井巷风流、火区火风压或节流效应影响条件下的扩散动力学特性以及细水雾与高温火灾环境的热质交换规律；设计并加工了细水雾发生装置，采用数值模拟的方法研究了其内部结构对气液旋转射流的动力学特性的影响，利用综合实验系统，测试了装置内部速度的三维分布，采用数值模拟与实验相结合的方法，理论上得出了不同气、水流动参数条件下的气液扰动的强度与氮气流速、氮气流量和喉管直径的关系及其对雾化效果的影响，基于该理论设计并优化了雾化装置，并进行了工业性试验与应用。