Radiation Heat Transfer Modelling and CFD Analysis of Pulverised-Coal Combustion with Staged Air Introduction

Abstract

Modelling of fossil fuel utility and industrial boilers has reached a remarkable development in recent years. Particular attention in optimisation of a utility boiler furnace operation, is given to the flame geometry and position. Combustion chamber designers endeavour to achieve optimum operating conditions that give maximum combustion efficiency, as well as minimum pollutant formation rate. The application of computational fluid dynamics (CFD) modelling technique and other advanced mathematical methods offer opportunities for analysis, optimisation and options examination in order to increase the overall efficiency of the energy facilities. The main purpose of the present study was to investigate 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 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.