The Simulation Of Heat Transfer Behavior In The CDQ Unit Based On The Dual Mesh Technology

The heat transfer process between the high-temperature coke and the cryogenic gas in a 140 t/h coke dry quenching(CDQ)furnace was investigated in this paper.Based on Fluent software platform,the CDQ model was meshed by ICEM and then the grid area was transferred into two separate calculation areas by dual mesh technology,i.e.the coke falling zone and the gas flowing zone.Also,the corresponding differential equations of heat transfer in separate regions were established.The correlation between the two regions was built by UDF to simulate the flow and heat transfer process between the coke and the cryogenic gas in CDQ.Then the heat transfer process was simulated by changing the process conditions of the factors which affect the heat transfer between coke and gas in CDQ.The results show that:(1)Speed segregation occurs when gas enters the chute and the coke falls.The heat transfer effect around the CDQ furnace wall is better than that in the center.(2)With a smaller coke rate and a larger gas velocity,a smaller size of the coke particles and a bigger porosity of the packed coke,the outlet temperature of coke is lower.With a smaller coke rate,a smaller gas velocity,a smaller size of the coke particles and a smaller porosity of the packed coke,the outlet temperature of gas is higher.In order to guarantee proper outlet temperatures of coke and gas simultaneously,above factors should be controlled.