Flow characteristics analysis and combustion oscillation mitigation of a hydrogen industrial burner

Abstract

With the promotion of carbon neutrality policies, hydrogen burners are widely used in the industrial field, and exploring the combustion characteristics and stable combustion technology of hydrogen industrial burners has important engineering application significance. This study investigates the flow characteristics and combustion oscillation mitigation of a specific hydrogen industrial burner for heating thermal oil through experiments and numerical simulations. The oscillating combustion with a frequency of 100 Hz is discovered during the field test. The dynamic characteristics are reproduced via large eddy simulation (LES), and the pressure amplitude is reduced by 22% via the active control strategy. LES results show that corner recirculation zone and main recirculation zone occur in the flame holding chamber, with maximum recirculation velocity and maximum temperature of −20 m/s and 2110 K, respectively. The unstable modes and key elementary reactions are revealed by modal analysis and eigen-analysis. The clustered neural network with horizons (CNNH) controller is constructed to suppress the combustion instability. The CNNH controller can effectively suppress the pressure oscillation by perturbing the inlet mass flow rate of main H2, reducing the peak amplitude in the frequency domain by 67%. By optimizing the controller parameters, the CNNH controller can be further applied to different scenarios of hydrogen industrial burners.