Simulation of Combustion and Thermal Flow in an Industrial Boiler

Abstract

Industrial boilers that produce steam or electric power represent a crucial facility for overall plant operations. To make the boiler more efficient, less emission (cleaner) and less prone to tube rupture problems, it is important to understand the combustion and thermal flow behaviors inside the boiler. This study performs a detailed simulation of combustion and thermal flow behaviors inside an industrial boiler. The simulations are conducted using the commercial CFD package FLUENT. The 3-D Navier-Stokes equations and five species transport equations are solved with the eddy-breakup combustion model. The simulations are conducted in three stages. In the first stage, the entire boiler is simulated without considering the steam tubes. In the second stage, a complete intensive calculation is conducted to compute the flow and heat transfer across about 496 tubes. In the third stage, the results of the saturator/superheater sections are used to calculate the thermal flow in the chimney. The results provide insight into the detailed thermal-flow and combustion in the boiler and showing possible reasons for superheater tube rupture. The exhaust gas temperature is consistent with the actual results from the infrared thermograph inspection.