二甲醚/空气/氩气混合物的爆炸特性

在20 L球形爆炸容器中对二甲醚/空气(DME/air)、二甲醚/空气/氩气(DME/air/Ar)混合物在不同初始状态下的爆炸特性进行实验研究，分析了不同初始压力、不同氩气(Ar)稀释浓度对爆炸极限、最大爆炸压力以及最大爆炸压力上升速率的影响。结果表明:DME/air混合物的最大爆炸压力和最大爆炸压力上升速率与DME在混合物中的浓度呈圆顶形关系，最大值出现在DME在混合物中的浓度为6.5%(即最佳当量比, φ=1)附近；初始压力的下降明显降低了DME/air混合物的爆炸上限，但对于其爆炸下限影响不显著；Ar的稀释对富燃DME/air混合物的最大爆炸压力和最大爆炸压力上升速率有显著的惰化作用，但对于贫燃DME/air混合物，最大爆炸压力和最大爆炸压力上升速率在一定的Ar稀释浓度范围内出现上升趋势，当Ar的稀释浓度大于20%，这2个爆炸参数值逐渐下降。

Explosion characteristics of dimethyl ether/air/argon mixtures

Explosion characteristics of dimethyl ether (DME)/air and DME/air/ argon (Ar) mixtures were studied by using a 20-L spherical explosion-containment vessel under different initial conditions. This paper analyzed the effects of different initial conditions (e.g., pressures, Ar dilution) on the explosion parameters including explosion limits, maximum explosion pressure and maximum rise rate of explosion pressure. A dome-shaped relationship was found between maximum explosion pressure and DME concentration. And there lies a dome-shaped relationship between maximum explosion pressure rise rate and DME concentration. Their maximum values appear in the vicinity of the stoichiometric composition. Lowering the initial pressure can significantly decrease the upper flammability limit, but has no influence on the lower explosion limit. For fuel-rich DME/air mixtures, Ar dilution can greatly decrease the maximum explosion pressure and the maximum rise rate of explosion pressure. For fuel-lean ones, in a certain range of Ar concentration, the maximum explosion pressure and the maximum rise rate of explosion pressure increase with the increasing of Ar concentration. And these explosion parameters decrease eventually with the increasing of Ar concentration over 20%.