Experimental study of gas deflagration temperature distribution and its measurement

Explosion temperature is one of the main factors in combustible gas explosion accidents. Despite all this, this problem has not yet received considerable attention, especially few fundamental data related to the temperature distribution of gas explosions in closed vessels in literatures. According to characteristics of gas deflagrations, this work developed a gas explosion temperature measurement system whose response time to temperature is approximate 10 μs. By using this system, an experimental study was carried out which is concerned with the deflagration temperature distribution of premixed methane-air mixtures in the 20. L spherical vessel with a diameter of 168. mm. Experimental results show that temperatures on or near the wall are obviously lower than those in the center part of the vessel and there is a conspicuous gradient from the wall to the center part of the vessel. In the inside of the vessel, the deflagration temperature of premixed methane-air mixtures near the ignition spot at the center of the vessel can approximately reach 1200 °C, while near the wall, only 300 °C. This result throws a light on the specific regularity of gas temperature distribution near the boundary. It is possible to provide an important basis for understanding the general characteristics of gas deflagrations in closed vessels as well as choosing good measurement designs. Otherwise, if the ignition is located in the geometrical center of the spherical vessel, velocity of the flame increases with the distance away from the center inside the vessel, and when the flame arrives at the inner wall, this velocity descend sharply.