Investigation On Influential Factors Of Explosion Pressure Venting Of Methane/Hydrogen/Air Mixtures

In order to cope with the energy crisis and environmental pollution caused by traditional fossil fuels,hydrogen fuel,as a clean alternative energy,has attracted the attention of many scholars at home and abroad,and the safety problem of hydrogen utilization is the key to the application of hydrogen technology.Therefore,the subject was based on the issue of the safe use of combustible gas,studied the flame propagation characteristics of methane/hydrogen/air mixtures explosion through the independent designed cuboid tube,by using the high-speed camera,pressure sensors and other measuring methods.The influencing factors of different opening area,static opening pressure and obstacles were analyzed in detail,and the flame propagation and venting characteristics of methane/hydrogen/air mixtures explosion in the tube were revealed.The main contents and conclusions of this paper are as follows:(1)A set of small-sized gas explosion pressure relief experimental pipeline is designed,which can be used to capture the dynamic flame course by high-speed camera system.By using the explosion-venting system,ignition device and gas distribution system,high-frequency dynamic pressure sensor and data acquisition and control system to build the experimental platform of multivariate gas explosion pressure venting.(2)The propagation process of methane / hydrogen / air premixed flame would produce pressure wave,the co-directional pressure wave to promoted flame propagation,the reflected pressure wave suppressed flame propagation.In the case of large opening area,the peak value of flame propagation was higher and the peak time was longer.(3)The propagation process of a premixed flame in the tube,the early stage was the changing process of the flame front structure under the action of pressure wave in,and the later period was the development of the turbulent flame.The rupture of the venting membrane was mainly caused by the combined effect of the flame and the explosion pressure.The dynamic venting pressure is smaller than the static action pressure.The larger the thickness of the venting membrane,the greater the deviation between the dynamic venting pressure and static action pressure.(4)Obtained through the experiment of the rectangular tube with obstacles found that,the development process of methane/hydrogen explosion pressure in pipeline mainly consists of three phases,which were slowly rising,rapid increasing and falling sharply,while the flame propagation velocity in the tube increases firstly and then decreases.The obstacles have a significant influence on the flame propagation in the tube,and the structure of the flame front is changed significantly,and lead to accelerate flame propagation.