泄爆条件对管内气粉两相混合体系燃爆特性的影响OA北大核心CSTPCD

To investigate the variation law of the blasting characteristics of the gas-powder two-phase mixed system,blast experiments with different outlet static action pressures (pst) were carried out in a self-built stainless steel flame acceleration pipeline,and the variation law of pst on two-phase blasting pressure,flame propagation velocity,and blasting flame morphology was emphatically studied. pst is determined by the blasting hole blocking ratio (θ) and the number of blasting film layers (n). The increase of θ and n together increases pst. The increase of pst strengthens the constraint of gas powder and reaction products flowing out of the pipe,increases the viscosity effect of the fluid in the pipe,promotes the reaction of gas powder in the pipe,and reduces the degree of secondary explosion of unfired gas outside the pipe. For the pressure-time interval curve analysis,pst increases from 2.97 kPa to 14.64 kPa,and the pressure time interval curve shows a double peak structure with a keep platform. The first pressure peak increases from 5.48 kPa to 10.20 kPa,the keep time extends from 6 ms to 25 ms,and the second pressure peak decreases from 23.03 kPa to 9.71 kPa. When pst is 16.08 and 24.12 kPa,the pressure before the bursting film is superimposed and reflected many times,resulting in the time-history curve of bursting film pressure showing a special oscillating and rising three-peak structure. In the analysis of flame propagation velocity,the increase of pst decreases the average flame propagation velocity from 161.33 m/s to 67.99 m/s. When n=2,the increase of θ makes the flame structure change from cluster to jet. When θ=88.9％,the blasting flame shows a typical jet shape. The increase of θ and n makes the flame brightness gradually decrease,the length of the flame luminescence zone decreases,the time interval from breaking film to flame emergence and the flame duration increase.