Producing Mechanism And Preventing Technical Research Of Pulverized Coal Deposit In The Pulverized Coal Feeding Pipeline

In the first place,to introduce the pneumatic conveying technology and CFD computational fluid mechanics in modern industrial application.To describe all kinds of force about the pulverized coal in air mixed fluid by gas solid two-phase flow theory of dilute phase pulverized powder,and combined with the existing experimental demonstration results to confirm the air drag force of pulverized coal is the main factors that affects the movement of pulverized coal.Otherwise,in the vertical direction,when the drag force of pulverized coal particles is small,the gravity of pulverized coal particles cannot be ignored.Then,for DG670-13.78/8A of Shengli Power Plant ultrahigh high pressure pulverized coal boiler powder feeding system,to determine the suspension velocity of the 5~505?m spherical particle by utilizing pneumatic conveying engineering calculation method,and put forward the correction method of the actual irregular shape of pulverized coal particles suspension velocity.Secondly,to set up a number of powder feeding pipeline model by using the Fluent15 software,and to simulate the movement process of 5~175 ?m pulverized coal powder in the powder feeding pipeline by using the CFD particle track model.To determine the formation of swirl formed by suspension of air phase after elbow has an important role on the subsequent straight pipe of pulverized coal through judgment of the results of the calculation of the data,and when the installation way,angle of bending as well as bend radius of elbow are different and the distribution of air eddy is also different,the role of different parts of eddy is different,the outlet elbow straight pipeline along the rising flow velocity distribution is different,resulting in the big difference about the forward distance of the pulverized coal in these pipes in a suspended state.Finally,this paper puts forward a scheme of air flotation device installed at the bottom of powder feeding pipe,to strengthen the up-welling intensity along the pipeline,and to fluidify the existing sedimentary layer at the bottom of the pipe,so as to deposit the pulverized coal in the retarding flow,eliminate bottom sediment layer.To simulation calculate and analyze impact of changes about the air flotation equipment to flow field by using the CFD computational fluid mechanics.Finally,the long time actual industrial application proved that the proposed scheme can achieve the desired effect.