Oxyfuel Combustion in Gaseous-Fuel Tangentially-Fired Boilers

Tangentially-fired furnaces are widely used in large steam generation units of thermal power plants and process industry. These furnaces are vortex-combustion units and have uniform gas temperature distribution. Oxyfuel combustion is one of the well known technologies used for reduction of CO2 and eliminating NOx emissions. In this technology, oxygen is burnt in a combustion chamber with fuel and the combustion products include only carbon dioxide and water vapour. These two gases can be easily separated by simple H2O condensation process. The separated CO2 can, then, be recycled or stored through the storage processes. The present study aims to investigate numerically the problem of oxyfuel combustion of turbulent reacting flows in a model furnace of a tangentially fired boiler. This problem is very essential for the power production sectors due to its relation to steam generation in large boiler furnaces used in thermal power plants. In the present work, numerical calculation of the flow field and thermal fields as well as the species concentrations for the oxyfuel combustion in the furnace of a gaseous-fuel tangentially-fired boiler will be provided. The investigation will cover a range of different parameters including the flow rates and carbon dioxide recirculation percent. The details of the flow, thermal and combustion fields are to be obtained from the solution of the equations that govern the conservation of mass, momentum and energy and transport equations for the scalar variables in addition to the equations of the turbulence, combustion and radiation models.