Xiao Lu, Gong Xuanping, Cheng Xiaoyu, Cheng Cheng, Ye Zhengliang, Ma Xingying, Gan Hailong
China Coal Energy Research Institute Co., Ltd., Xi'an 710054, China.
China Coal Technology Engineering Group Chongqing Research Institute, Chongqing 400037, China.
ACS Omega. 2025 Aug 1;10(31):34352-34362. doi: 10.1021/acsomega.5c02053. eCollection 2025 Aug 12.
In order to ensure the safety of the coalbed methane pump station and the underground coalbed methane extraction system, the low-concentration coalbed methane transmission pipeline needs to be installed with fire arresters. The traditional fire arrester design is not standardized, the reliability of the fire prevention effect is low, and the resistance is large. Based on the theory of flame quenching, through numerical simulation and experimental methods, this paper studies the structure of fire arresters suitable for the safety assurance system of low-concentration coalbed methane transportation, so as to provide safety assurance for the raw gas transmission of low-concentration coalbed methane utilization devices. The results are stated as follows: After the coalbed methane explosion, the flame accelerates along the direction of propagation within the pipeline. The pressure of the shock wave inside the pipeline reaches its maximum value and then decreases and stabilizes. When the flame encounters obstacles within the pipeline, there is a noticeable jump in both flame speed and pressure. Flame arresters installed in low-concentration coalbed methane utilization systems should be equipped with corrugated plate flame-arresting cores that have sufficient mechanical strength to resist the sudden increase in pressure and velocity. To accelerate the cooling of the flame during propagation and reduce resistance, the diameter of the central flame-arresting core should be sufficiently large. For the optimized DN500 dry flame arrester, the optimal diameter of the flame-arresting core is 1500 mm, the expansion angle of the flame arrester housing is 30°, the spacing between corrugated plates is 30 mm, the thickness of the corrugated strip is 0.25 mm, and the number of corrugated plates is 2. When the flow velocity of the coalbed methane is 15 m s, the resistance is 670 Pa. Experimental tests have shown that when the flame propagation velocity is below 775 m s, the flame arrester can successfully interrupt the flame propagation.
为确保煤层气泵站及井下煤层气抽采系统的安全，低浓度煤层气输送管道需安装阻火器。传统阻火器设计不规范，防火效果可靠性低且阻力大。基于火焰淬熄理论，通过数值模拟和实验方法，本文研究适用于低浓度煤层气输送安全保障系统的阻火器结构，为低浓度煤层气利用装置的原料气输送提供安全保障。结果如下：煤层气爆炸后，火焰沿管道内传播方向加速。管道内冲击波压力达到最大值后下降并稳定。当火焰在管道内遇到障碍物时，火焰速度和压力均有明显跃升。安装在低浓度煤层气利用系统中的阻火器应配备具有足够机械强度以抵抗压力和速度突然增加的波纹板阻火芯。为加速火焰传播过程中的冷却并降低阻力，中心阻火芯的直径应足够大。对于优化后的DN500干式阻火器，阻火芯的最佳直径为1500mm，阻火器外壳的扩张角为30°，波纹板间距为30mm，波纹带厚度为0.25mm，波纹板数量为2块。当煤层气流速为15m/s时，阻力为670Pa。实验测试表明，当火焰传播速度低于775m/s时，阻火器能成功阻断火焰传播。
