Pulverised-Coal Combustion with Staged Air Introduction: CFD Analysis with Different Thermal Radiation Methods

Abstract

Combustion chamber designers endeavour to achieve optimum operating conditions that give maximum com- bustion efficiency, together with minimum pollutant formation rate. Modelling of fossil fuel utility boilers has reached a remarkable development in recent years. Particularly, the application of computational fluid dynamics (CFD) modelling technology and other advanced mathematical methods offer opportunities for analysis, optimisation and options examina- tion in order to increase the overall efficiency of the energy facilities. The main purpose of the present study was to inves- tigate how the results obtained with two radiative heat transfer methods, the P1 approximation method and the discrete ordinates (DO) method, fit temperature field in a boiler furnace on pulverised coal, with implemented over-fire air (OFA) ports. The overall framework of the CFD modelling approach is described. The numerical modelling results for boiler baseline operating conditions are compared with a test matrix of local temperature measurements. An accuracy analysis of the P1 and DO methods is done on a basis of a comparison between the numerically obtained and measured temperature profiles.