Geometrical parameter evaluation of a 0.5 MWth bench-scale oxy-combustion burner. (1st January 2015)

• Record Type: Journal Article
• Authors: Vega, F.; Benjumea, F.; Navarrete, B.; Portillo, E.
• Is Part Of: Fuel. Volume 139(2015)
• Page Start: 637
• Page End: 645
• Publication Date: 2015-01-01
• Subjects: Oxy-combustion -- CDF -- Oxy-burner -- Flame stability -- CO2 capture; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2014.09.035
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Oxy-combustion is presented as a new promising CCS technology for fossil-fuel power plants. A 0.5 MWth bench-scale oxy-burner using coal as fuel were evaluated using a CFD model. The behaviour of the burner has been evaluated operating under oxy-combustion conditions. Three key geometrical parameters have been optimized to improve the oxy-burner performance and coal ignition. Abstract: Carbon capture and storage (CCS) technologies are one of the most relevant energy pathways to mitigate medium-term climate change effects. They will contribute up to 20% of the total CO2 emission reduction by 2035. Oxy-combustion is considered a promising CCS technology applicable in fossil-fuel power plants. Much effort has been made to develop oxy-combustion at large scale. However, there are still fundamental issues and technological challenges that must be addressed before this technology can be considered for commercialization. Recent research on coal oxy-combustion experimental facilities indicates stabilization problems and ignition delays when combustion occurs in CO2 -rich environments. Advanced burner designs are required to ensure technological and economic feasibility of the process. Computational Fluid-Dynamics tools were used to evaluate the behaviour of a 0.5 MWth bench-scale oxy-burner. Key geometrical parameters were analysed, such as combustion chamber diameter, chamber length and angle of the quarl. Simulations showed that a length of 6 m ensures complete coal combustion. The results indicated that the combustion chamber diameter and the quarl angle have an influence on coal ignition, stability, flame shape and CO concentration. Higher values of those parameters produced greater hot recycled flow, which means higher temperatures and greater flame stability. Coal ignition was also improved. A 1500-mm chamber diameter and a 50° quarl angle were selected as optimal values for both parameters. CFD modelling makes it possible to analyse the behaviour of different oxy-burner configurations and to optimize the combustion process under oxy-combustion conditions.