| In the context of the global energy crisis,many countries around the world advocate low-carbon energy,and China’s energy structure is also changing to low-carbon energy.The proportion of natural gas is increasing.Natural gas is not only widely used but also cheap.After being mined and processed,it is not only supplied to cities and towns as gas energy,but also used in industrial production activities such as chemical production and industrial power.Although natural gas has many advantages,it still has certain disadvantages.The main component of natural gas is methane,which has the disadvantages of small flammable limit range and slow flame propagation speed.In addition,it is a flammable and explosive gas,and there will be certain safety hazards during its mining,transportation,storage and use,which seriously threatens China’s economic development and life safety.In order to improve the combustion performance of natural gas and the safety of natural gas in the transportation and using.In this paper,through two sets of experimental test system,including stainless steel pipe,plexiglass square pipe and suppression explosion chamber,and combined with high-speed camera,pressure sensor,noise sensor and other advanced test instruments,the methane air explosion flame was studied.The effects of H2 and argon on the propagation characteristics of methane-air deflagration flame,the suppression of deflagration process of methane-air with suppression explosion chamber,and the suppression of noise and vibration of methane air deflagration flame by polyester fiber cotton were studied.The main conclusions are summarized as follows(1)The effect of H2 on the flame propagation characteristics of methane-air deflagration flame was researched.It is found that the propagation speed and pressure of deflagration flame are not only affected by H2,but also by the rupture degree of the film at the nozzle.When the equivalence ratio is low,the addition of H2 can effectively increase the flame propagation speed and deflagration pressure.When the equivalence ratio is high,with the increase of H2 content,the damage degree of the film at the nozzle increases,so that there are more unburned gases rushing out of the pipeline,resulting that the flame propagation speed decreases,the first pressure peak of the deflagration pressure curve increases,and the second pressure peak decreases(2)The effect of argon on the flame propagation characteristics of methane-air flame was investigated.It is found that the instability of flame front increases with the addition of argon,and argon can effectively reduce the propagation speed and deflagration pressure of methane air deflagration flame.(3)The suppression effect of the suppression explosion chamber on the characteristics of flame propagation velocity,overpressure and other characteristics was investigated.It was found that the explosion suppression ring in the detonation chamber had a buffering effect on the gas discharge in the pipeline and reduced the deflagration flame propagation speed.The development trend of the deflagration pressure curve has three pressure peaks due to "membrane breakage","external explosion" and "flame oscillations intensifying turbulence".The porous structure on the suppression explosion ring inside the detonation chamber serves as a buffer and quenching a portion of the deflagration flame at the nozzle reduces the second and third pressure peaks(4)In the plexiglass square tube,the inhibition effect of polyester fiber cotton on methane-air deflagration flame was studied,and the deflagration flame noise curve combined with vibration curve was analyzed in detail.It was found that the polyester fiber cotton arranged in the plexiglass square tube could reduce the peak velocity of flame propagation,at the same time,it could reduce the noise sound pressure level and vibration velocity of deflagration flame It is found that there is a certain coupling relationship between the noise of gas deflagration flame and the pipe wallFigure[57]table[12]reference[86]... |
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