The Study On Experimental System Of Explosion Suppression By Powder In The Limited Space

In the current experimental study of the explosion suppression,small and medium-sized experiments are usually carried out by pre-spraying anti-explosive media.This kind of research has made some contribution to the explosion suppression,but the conclusions can not be directly applied to the practical application.In the large explosion suppression experiment,it is usually judged by the macroscopic conditions,so it is difficult to explore the effect of explosion suppression by suppressor.In this paper,by the review of a large number of literatures,designing the anti-explosive experimental system which including the explosion test system and the suppressor.After debugging,the optimal parameters of the system are determined.Finally,the actual explosion suppression effect of the designed suppressor was verified by the explosion suppression experiment.And the explosion suppression law is explored.The study mainly include the following aspects:(1)Design and construction of the explosion experiment system.A 100 L horizontal round cylindrical explosion test vessel which can observe the internal situation of the device was designed.Building gas distribution system,ignition system and data acquisition and control system.The gas distribution system used the partial pressure method to mix gas.The ignition system used the EDM to ignite the gas.The data acquisition and system used the USB2805 C acquisition card and the micro controller STM32 to realize the collection and the linkage control to the whole explosion test system.(2)Design of the suppressor and its assembly.Using the gas generator which was mainly used in the automotive airbag industry to assembly a suppressor.By the analysis and calculation,the minimum amount of powder required for the suppressor was 100 g.After determining the structural parameters of the suppressor,three kinds of suppressor assembly scheme were determined according to the area ratio of the side hole and the bottom hole of the gas generator.And the media was the ultra-fine ABC dry powder.(3)Debugging the explosion suppression experiment system and determining suppressor assembly program.Through the debugging experiment to determine the ignition electrode spacing of 2mm,in which the ignition success rate of 95%,the average ignition delay of 3.5ms,the average ignition energy of 2.54 J.The parameter of High-speed camera was that aperture was 5.6,focal length was 83 mm,the resolution was 960 × 960,the shooting frame rate was 4000 frames / sec.In the assembling condition,the breaking pressure of the suppressor was 5.9MPa,and the time interval from the suppressor to the suppression of the medium was only 4ms,which was very ideal for the suppressor.(4)Experimental analysis and the effect of explosion suppression.The experiment was proved that the designed explosion suppression experiment system can realized the analysis of data and image.The law of explosion suppression in this experiment was that the earlier the suppressor was triggered,the better the explosion suppression effect.And the amount of powder plays a decisive role in the detonation effect.The more the amount of the powder was,the more the control and weakening effect of the high-speed jet formed by the suppressor,and the higher the dust cloud concentration,the effect of the inhibition of flame propagation was more obvious.Under the condition of the trigger time of 90 ms and the powder amount of 400 g,the suppressor can completely suppressed the explosion of the methane / air premixed gas.