Numerical Simulation And Analysis Of The Dry Slag Discharge Machine Based On The Coupled Heat Transfer

Dry slag extraction is a new discharge technology solution which is generated inthe situation that fresh water resource is in shortage and the environmentalrequirement is improved day by day. There is a complex flow and heat transferprocess in the dry slag extraction machine, with the gradual localization of dry slagextraction technology the internal flow and heat transfer characteristics are consideredto be the main problem in the thermal design of the dry slag extraction system.Considering that the cold air damper is uncontrollable and the inlet air rate in themaximum load should have a over-measure (margin) in the design of the slagextraction machine, we adopt the numerical simulation of coupled heat transfermethod, change side pods location of the dry slag discharge machine and explore theinternal influence rules in order to reduce the air leakage.Firstly, we establish mathematical model in allusion to the studying object andalso simulate its internal air flow characteristics, ash and slag heat exchange, thenmade a comparison with the experimental results which verifies the feasibility ofstudying this type of problem using coupled heat transfer numerical simulationmethod. The influence of different operation parameters on the flow and heat transferis simulated. The inlet cold air rate in the slag extraction has a linear growth tendencywith the pressure differential between the import and the export. We also find thatwhen the pressure differential changes, the velocity changes of the air inlet on bothsides are consistent and the influence towards the temperature of ash caused by therunning speed of the slag extraction machine is linear, so we should adjust therunning speed of the steel belt reasonably according to the slag quantity in theoperation.Secondly, we change the arrangement of the side air vents and build differentcalculating model. By analyzing distribution of the inner flow field and the ash temperature field when the air vents are in different alignment decorations, we cansee that stagger vent arrangement can effectively enhance internal airflowdisturbances of the extraction machine which can improve the ash heat transfer. Thenwe change the number of the vent in the horizontal segment in the extraction machineand the result shows that when the number of the vent in the horizontal is12, the flowfield in the upper storey distribution is uniform, the temperature drop capacity in thehorizontal segment of the slag storey is larger and the temperature of the outlet slag islower.