Numerical Research of the Modification of the Combustion System in the OP 650 Boiler

Abstract

Changes in the combustion system are one of the paths leading to improved combustion quality. This is manifested by a reduction of the unburnt carbon in fly ash and slag and a reduction in harmful emissions. The article presents the numerical analysis of the modification of the combustion system in the OP 650 boiler. The modifications consisted of changing the direction of swirl of the dust–air mixture in individual burners and changing the distribution of air to Over-Fire Air (OFA) nozzles. These had an impact on NOx and CO emissions and the temperature achieved at the outlet of the chamber. The content of O2, CO, and NOx emissions, flue gas temperature at the outlet from the chamber, flue gas temperature after the platen superheater, as well as temperature at the outlet from the model were presented. The percentage of coal flow directed towards the slag hopper was also noted.

Numerical Studies of the Influence of Flue Gas Recirculation into Primary Air on NOx Formation, CO Emission, and Low-NOx Waterwall Corrosion in the OP 650 Boiler

“…The numerical mesh, consisting of 6,576,794 numerical cells, is shown in Figure 5 The superheaters were managed as a porous area constructed in the form of sheets, heated with flue gas as described in [24]. A geometric model of the OP 650 boiler RAFAKO Racibórz from Poland, including individual stages of the live-steam (LS) and reheated-steam (RS) superheaters, is shown in Figure 4.…”

“…The numerical mesh, consisting of 6,576,794 numerical cells, is shown in Figu The superheaters were managed as a porous area constructed in the form of sheets, he with flue gas as described in [24]. The numerical mesh, consisting of 6,576,794 numerical cells, is shown in Figure 5.…”

Study on Slagging Characteristics of Boiler Pre-combustion Chambers Based on Deep Learning

“…Among them, the Realizable k – e turbulence model is used to simulate the mixing of flue gas in the furnace, 22 the DPM model (discrete phase model) is used to simulate the complex gas–solid two-phase flow, 23 the P-1 model is used to calculate the high temperature radiation heat transfer in the furnace, 24 and eddy dissipation is used to simulate the volatile gas phase combustion. 25 In addition, the double parallel competition model is used to simulate coal pyrolysis. 26 Finally, the dynamic/diffusion finite rate model is applied to simulate coke combustion.…”

“…In the numerical calculation of coal-fired boilers, due to the complexity of the pulverized coal combustion process in the boiler, many models are used in CFD simulation. Among them, the Realizable k – e turbulence model is used to simulate the mixing of flue gas in the furnace, the DPM model (discrete phase model) is used to simulate the complex gas–solid two-phase flow, the P-1 model is used to calculate the high temperature radiation heat transfer in the furnace, and eddy dissipation is used to simulate the volatile gas phase combustion . In addition, the double parallel competition model is used to simulate coal pyrolysis .…”

Determination of High Temperature Corrosion Rates of Steam Boiler Evaporators Using Continuous Measurements of Flue Gas Composition and Neural Networks

“…The results of such CFD modelling can be used to either cover these areas with protective coatings, introduce additional air nozzles, protecting walls from highly concentrated flue gas compounds and slag/ash deposition, or change, in general, the combustion process performance (air flows, burners modification, etc.) [10,11]. However, despite such sophisticated software and methods, there is a need to control the corrosion risks on-line and predict potential failure or corrosion rate.…”