Safety-Critical Combustion Control for Gas Boilers Using Control Barrier Functions

Besides an efficient operation of a gas boiler, ensuring a safe combustion across the operating range is essential. This becomes even more critical when burning hy-drogen instead of natural gas. The distinct characteristics of hydrogen and their effects on flame behavior necessitate stricter safety requirements. This paper investigates a novel method to contribute to the safe operation of a gas boiler by using control barrier functions (CBFs). Thereby, it demonstrates the potential of CBFs in the heating industry as a novel field of application. The system is represented by a Hammerstein model. In order to ensure the operation remains within a safe range, two CBFs and a high order control barrier function (HOCBF) are set up. The resulting safety filter is integrated into the combustion control loop and verified in simulation.