承压容器内甲烷爆炸及泄爆特性研究

Study on methane explosion and release characteristics in pressure vessels

开展了中低压和高压工况下甲烷空气爆炸及泄爆试验,分析了爆炸及泄爆过程压力、压升速率等参数变化规律。结果表明,在低压工况下,甲烷体积分数达到12%时,不同初压下升压速率均不超过10 MPa/s。体积分数小于11%时,最大爆炸压力与体积分数近似呈二次函数的关系,大于11%时最大爆炸压力明显下降。在高压工况下,低体积分数的甲烷对于升压速率的影响更为显著,各个初压下升压速率基本相同。当采用直径100 mm反拱开槽爆破片进行泄爆时,在低升压速率工况下,反拱带槽爆破片在各个工况下均有较好的动态响应能力,在高升压速率工况下,爆破片的动态响应能力降低。分析了不同应变率下爆破片断口形态的变化,低升压速率工况下断口为韧性断裂,在高升压速率下断口向脆性断裂转变。

Revealing the characteristics of explosive pressure rise and release in the pressure vessel is of great significance for the safe operation of the pressure vessel.However,there is currently limited research on the coherence of methane explosion in pressure vessels and the explosive release characteristics of reverse domed scored bursting discs.An experimental study on the pressure rise characteristics of methane-air explosion in a closed-pressure vessel is carried out under low-pressure and high-pressure conditions.The time history curves of pressure and time in the vessels are measured,and the variation laws of parameters such as pressure and pressure rise rate during the explosion and release process are analyzed.The results show that a high concentration of methane has a significant effect on the maximum explosion pressure and pressure rise rate under low-pressure conditions.When the methane volume fraction reaches 12%,the pressure rise rate is less than 10 MPa/s under different initial pressure.When methane volume fraction is below 11%,the relationship between the maximum explosion pressure and the concentration is approximately a quadratic function,and the maximum explosion pressure drops significantly when the methane volume fraction is over 12%.Under high-pressure conditions,the relationship between methane maximum explosion pressure,pressure rise rate,and concentration can be expressed linearly.The effect of a low concentration of methane on the pressure rise rate is more significant,and the pressure rise rate is almost the same at different initial pressures.The influence of the pressure rise rate on the release characteristics of the reverse domed scored disc is studied.Under the condition of a low-pressure rise rate,the release characteristic of the reverse domed scored bursting disc has a good dynamic response ability under different explosion pressure,and under the condition of a high-pressure rise rate,the dynamic response ability of the rupture disc decreased.The change in the fracture morphology of the bursting disc under different strain rates is analyzed.The fracture is ductile fracture under the condition of low pressure rising rate,and the fracture surface changes to brittle fracture under the condition of a high rising pressure rate.