Effect of hydrogen on combustion dynamics and acoustics measured in an atmospheric confined swirled flame generated by a cyclone burner in the transition from natural gas to sustainable fuel

The transition from traditional fossil fuels to zero carbon emission fuels has become an urgent necessity. However, this energy transition is complex, requiring further investigation not only from the side of combustion stability and nitric oxide emissions but also from the thermoacoustic perspective, to determine the suitability of current industrial combustor designs for new carbon-free fuels. A gradual shift from methane to hydrogen is considered a viable solution. This study focuses on experimentally investigating the thermoacoustic behavior of methane/hydrogen fuel blends. The experiments were conducted on a lab-scale 50 kW cyclone burner, testing various fuel blends ranging from pure methane to a 60% molar fraction of hydrogen. Variable length upstream tube is used to create self-excited oscillations. To this end a novel laboratory scale burner design was made allowing a low burner acoustic impedance like MW scale atmospheric furnaces. Dynamic pressure transducers and photomultiplier tubes (PMT) were employed to obtain a flame transfer function. Volume integrated rate of combustion fluctuations were measured on basis of a PMT signal. The data is acquired and post processed using the hardware and software provided by IFTA GmbH. It is observed that hydrogen addition increased pressure oscillation amplitudes and created low frequency behaviour of the combustor more dominant .