Energy | 2021
Numerical simulation of CO formation and reduction on flame propagation due to heat loss through the cooled wall
Abstract
Abstract 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\xa0MPa), and wall temperature (300 and 750\xa0K) 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\xa0MPa and the equivalence ratio of 0.5, the CO reduction rate at a wall temperature of 300\xa0K is only 16.8% of that at a wall temperature of 750\xa0K. This suggests that the control of heat loss through the wall could be key to effectively reducing the CO emissions from combustors.