Numerical calculations of the WR-40 boiler with a furnace jet boiler system

Abstract

The aim of this work was to develop a numerical model of combustion in the furnace of a WR-40 boiler equipped with a FJBS (furnace jet boiler system). Based on previous calculations [1] and measurements [2], appropriate competent sub-numerical models were developed to match a temperature value and composition of the flue gas obtained with measurements taken at the real working boiler. The FJBS System has eight in-furnace jet-pump ventilators that uses gas propulsion (compressed air). Its task is to mix the flue-gas and any substrates of combustion at vortex, fire it up, and alignment align the temperature field. Numerical modelling results for the combustion chamber of the WR-40 boiler was shown. The concentration of O2, CO, CO2 in the flue gas, the temperature of flue gas for the whole combustion chamber, the change of the mass fraction of H2O in the coal, and the change in the mass of coal particles along the grate were measured to demonstrate that the processes taking place during combustion of fuel on the grate was included in the numerical model (i.e., drying, degassing, the burning of carbon particles, and the burning of volatiles). Numerical calculations confirm measurement results qualitatively rather than quantitatively. Generally, the CFD (Computational Fluid Dynamics) modelling confirmed the conclusions from measurements. Obtaining reliable temperatures at the furnace chamber outlet using numerical modelling is possible based on the 0-dimensional model of the boiler. In order to get reliable results from numerical modelling, it is necessary to validate the model with real measurement data. The results obtained by numerical simulation show that the FJBS system aligns the field temperature and concentration and decreases CO in flue gas.