Numerical Simulation Of Shockwave Induce Deposited Coal Dust Influenced By The Obstacle

In our country, there are abundant fossil fuels, and it is a major energy consumer andproducing country. Coal have dominated by long-term in energy structure of our country, butit is still a very important national infrastructure of strategic materials in the next period oftime.Study the dust explosion mechanism and conditions, as well as gas explosion inducedeposited coal dust influenced by the obstacle by theoretical analysis and numericalsimulation method of combining. The main study content is: Establish a pipe model of gasexplosion induce deposited coal dust; Coal dust particle motion is discussed under the shockwave from the theoretical analysis and numerical simulation of both; Under the conditions setbarrier, respectively obstacles blocking rate, the number of obstacles, obstacles to coal dustrising pitch process was simulated. By numerical simulation the following conclusions:(1) Coal dust rising process experienced a total of three stages: accelerated rise stage,deceleration stage and pneumatic conveying stage. In the left of coal dust cloud show acurved hook in the rising stage, and almost all of the coal distribution in the lower half of thepipe model; Deceleration stage experienced a relatively short time, the coal dust cloud havehigher concentration, the majority of coal dust did not participate in the reaction; Coal dust inthe horizontal velocity rapidly in pneumatic conveying stage, coal dust particles start tospread the extension pipe, coal dust area is elongated.(2) Different obstacles blocking rate of coal dust can be of different effects, the impacton the distribution of coal dust cloud blocking rate of50%and75%more significant; Thelarger obstacle blocking rate, the shorter the coal dust particles in the horizontal direction oftransport distance; The greatest impact on the growth rate of the obstacles blocking the pressure was50%.(3) The greater the number of obstacles, the greater the peak pressure within the pipes,the shorter the peak arrival time elapsed. Under the multi-barrier case, the pressure will beback and forth oscillation phenomenon.(4) Obstacle smaller spacing on the peak pressure variation and a time variation of thepressure of6m and3m pressure when compared to no significant change.