Investigation of the Efficiency of the Flue Gas Recirculation during Natural Gas Combustion in the Boiler Furnace
Year: 2026
Type: article
Abstract: The aim of the work is to model and analyze the process of combustion of natural gas in a boiler furnace in a mixture with oxygen-enriched air while recirculating flue gases in various ways. To achieve this goal, the following objectives were addressed: the development of a mathematical model of a fire tube boiler furnace for operation during the combustion of natural gas in a mixture of air with pure oxygen and recirculated flue gases, a numerical study of the combustion process, including the temperature in the furnace and the composition of combustion products, depending on the method of recirculation. Combustion simulation was carried out in the computational fluid dynamics package OpenFOAM, using the XiFoam solver. The most important result is to obtain a formula for calculating the required degree of dryness of the recirculating flue gases, depending on the recirculation ratio and NOx emission limits. In addition, it was confirmed that the method of organizing flue gas recirculation is more efficient by feeding them in a mixture with an oxidizing agent going to combustion, compared to other methods, even under conditions of oxygen fuel combustion. The study was conducted for the recirculation ratio in the range from 0 to 50% with varying degrees of flue gas dryness. It is shown that controlling the moisture concentration in recirculated flue gases is an effective and technologically flexible tool for optimizing the natural gas combustion process in power boilers operating using oxygen combustion technology. The proposed approximation model makes it possible to estimate the required degree of dehumidification of recirculating gases at the design and commissioning stage, adapting the technology to the specific operating conditions of the power boiler and the requirements of environmental legislation.
Language: English
Subfield: Energy Engineering and Power Technology
Field: Energy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7172118912