Numerical simulation of CO formation and reduction on flame propagation due to heat loss through the cooled wall

• Published in: Energy (Oxford) Vol. 236; p. 121352
• Main Authors: Yunoki, Keita, Kai, Reo, Inoue, Shinpei, Kurose, Ryoichi
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-12-2021; Elsevier BV
• Subjects: Adiabatic; Carbon monoxide; Combustion chambers; Detailed reaction mechanism; Emissions; Equivalence ratio; Flame propagation; Gas turbine combustor; Gas turbines; Heat loss; Mathematical models; Non-adiabatic flamelet generated manifolds approach; Premixed flames; Reaction mechanisms; Reduction; Simulation; Wall temperature; Gas turbine combustor; Non-adiabatic flamelet generated manifolds approach; Heat loss; Carbon monoxide; Detailed reaction mechanism; Flame propagation
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2021.121352

To realize further low carbon monoxide (CO) emissions for industrial gas turbine combustors, the elucidation of the CO formation and reduction mechanism for lean premixed combustion is crucial. In this study, one-dimensional numerical simulations using a detailed reaction mechanism approach and two-dimensional numerical simulations using a detailed reaction mechanism approach or a non-adiabatic flamelet generated manifolds (NA-FGM) approach are applied to CH4-air premixed flames near a cooled wall. The effects of the equivalence ratio (0.5, 0.7 and 1.0), pressure (0.1 and 2.0 MPa), and wall temperature (300 and 750 K) on the CO emissions is investigated. The results indicate that the influence of the wall temperature is the most significant on the CO reduction rate. For the lower wall temperature, the CO reduction rate in the vicinity of the cooled wall becomes lower, thereby has a risk to increase the CO emissions. At the pressure of 2.0 MPa and the equivalence ratio of 0.5, the CO reduction rate at a wall temperature of 300 K is only 16.8% of that at a wall temperature of 750 K. This suggests that the control of heat loss through the wall could be key to effectively reducing the CO emissions from combustors.
•Numerical simulations are applied to CH4-air premixed combustion.•Detailed reaction mechanism or NA-FGM is employed and compared.•Heat losses affect CO emissions in the vicinity of the cooled wall.•CO reduction rate is most susceptible to wall temperature.•NA-FGM approach is capable of predicting CO emissions.