Method for monitoring and controlling combustion in fuel gas burner apparatus, and combustion control system operating in accordance with said method

A method is described for monitoring and controlling combustion in a burner (1) of a fuel gas apparatus, of the type comprising a sensor (8) with an electrode (El) located in or close to the flame and capable of being supplied by a voltage generator and also connected to an electronic circuit suitable for measuring the resultant potential at the electrode. The method comprises a first phase of acquiring and processing data from experimental conditions and a second phase of evaluating the desired combustion characteristic, under an actual operating condition of the burner. In the first phase a plurality of experimental combustion conditions for the burner (1) are preselected, applying to the burner in each of said conditions a power (PI, P2, Pn) and a further significant parameter of the combustion characteristics (Kl, K2, Km), under each of the experimental conditions applying an electrical voltage signal to said electrode (El) and carrying out a sampling of the response signal, calculating, on the basis of the sequence of sampled values, the characteristic parameters of the waveform of the signal for each of the experimental conditions, for the purposes of calculating a correlation function, on the basis of the acquired experimental data, capable of unambiguously correlating the power and the further significant parameter of the combustion characteristics with the characteristic parameters of the waveform of the signal at the electrode. The second phase comprises the steps of applying a voltage signal to the electrode (El) and carrying out sampling of the resultant response signal, calculating, on the basis of the sequence of sampled values, the characteristic parameters of the waveform of the response signal at the electrode, and calculating the estimated value of the desired combustion characteristic by using the correlation function.