Chen Xiaokun, Zhao Tenglong, Cheng Fangming, Lu Kunlun, Shi Xueqiang, Yu Wencong
School of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an, Shaanxi 710054, PR China.
Shaanxi Key Laboratory of Prevention and Control of Coal Fire, Xi'an University of Science and Technology, Xi'an, Shaanxi 710054, PR China.
ACS Omega. 2023 Mar 15;8(12):10863-10874. doi: 10.1021/acsomega.2c07053. eCollection 2023 Mar 28.
To characterize the inerting effect of N/CO mixtures containing various proportions on methane-air explosions, a series of experiments were conducted in a 20 L spherical vessel under the normal temperature (25 °C) and normal pressure (101 kPa). Six concentrations (10, 12, 14, 16, 18, and 20%) of N/CO mixtures were selected to analyze the suppression of methane explosion by N/CO mixtures. The results indicated that the maximum explosion pressure ( ) of methane explosions was 0.501 MPa (17% N + 3% CO), 0.487 MPa (14% N + 6% CO), 0.477 MPa (10% N + 10% CO), 0.461 MPa (6% N + 14% CO), and 0.442 MPa (3% N + 17% CO) in the presence of the same N/CO concentration, and similar decreases in the rate of pressure rise, flame propagation velocity, and production of free radicals were observed. Therefore, with the increase of CO concentration in the gas mixture, the inerting effect of N/CO was enhanced. Meanwhile, the whole process of the methane combustion reaction was affected by N/CO inerting, which was mainly attributed to heat absorption and dilution of the N/CO mixture. N/CO with a greater inerting effect leads to lower production of free radicals under the same explosion energy and a lower combustion reaction rate at the same flame propagation velocity. The findings of the current research provide references for the design of safe and reliable industrial processes and the mitigation of methane explosions.
为了表征含有不同比例的N/CO混合物对甲烷 - 空气爆炸的惰化效果，在常温（25°C）和常压（101 kPa）下于20 L球形容器中进行了一系列实验。选择六种浓度（10%、12%、14%、16%、18%和20%）的N/CO混合物来分析N/CO混合物对甲烷爆炸的抑制作用。结果表明，在相同的N/CO浓度下，甲烷爆炸的最大爆炸压力（ ）分别为0.501 MPa（17% N + 3% CO）、0.487 MPa（14% N + 6% CO）、0.477 MPa（10% N + 10% CO）、0.461 MPa（6% N + 14% CO）和0.442 MPa（3% N + 17% CO），并且观察到压力上升速率、火焰传播速度和自由基生成量有类似的下降。因此，随着气体混合物中CO浓度的增加，N/CO的惰化效果增强。同时，甲烷燃烧反应的全过程受到N/CO惰化的影响，这主要归因于N/CO混合物的吸热和稀释作用。在相同爆炸能量下，具有更大惰化效果的N/CO导致自由基生成量更低，并且在相同火焰传播速度下燃烧反应速率更低。当前研究结果为安全可靠的工业过程设计和甲烷爆炸缓解提供了参考。
