Design Of3MW_th Burner And Numerical Simulation On Oxy-fuel Combustion

With the increasing CO₂emission, the global warming has already attracted anextensive attention. Due to high efficient effect of CO₂reduction,the oxy-fuel combustionhas become a significant topic about energy saving and emission reducing. Accordingly, theoxy-fuel combustion technology has a bright prospect.The design of burner in oxy-fuel combustion is the key issue to which can make thetechnology industrialize. Currently, more and more institutes and suppliers spare no effortsto research the designing method on oxy-burner.The3MW_thswirling oxygen burner has been researched and developed, which wasapplied to the first system of the pilot-scale demonstration rigs belong to the State KeyLaboratory of Coal Combustion of Huazhong University of Science and Technology. Thereare two parts include in this paper: one is the design of oxy-burner and the other is thenumerical simulation on the characterization of oxy-fuel combustion.The design methodology on oxy-fuel burner is proposed. The style of stagedcombustion on the air-firing is used, but is not used on the condition of oxy-fuel conditions.This method can make the flow field of the oxy combustion and air combustion similar to acertain extent. Furthermore, it can promote the formulation of the internal recirculationzone and enhance the stability of combustion.The numerical simulation on various conditions has been done by this paper, forillustration, air combustion, oxy-combustion, dry cycle, wet cycle and oxygen injection.According to the analyzed results, we can conclude that: on dry cycle, the partial pressureof O₂comes to26.1%, the radiation and convection flux will be consistent with the aircombustion. While the partial pressure of O₂reaches30.4%，the radiation flux andconvection flux will be the same with the air combustion on wet cycle; the ignition placewill move forward due to the increasing of the fraction of O₂in primary air; the velocity ofsecondary air of oxygen combustion can greatly impact on the formation of the internalrecirculation; the injection of O₂can cause the delay of ignition, internal recirculation zonewill be also scattered by the oxygen with high injection velocity, thus the uncompletedcombustion will happen.