Investigation into the thermo-acoustic instability for oxyfuel combustion with CO2 dilution in a gas turbine model combustor

Environmental degradation caused by global warming is mainly a result of carbon-dioxide (CO2) emissions to our atmosphere. It is largely emanating from fossil-based-fuels combustion that meets about 85% of our energy demands globally. Oxyfuel combustion as a means for reducing CO2 emission is one of the promising technologies gaining attention rapidly. This is because when used together as a carbon capture and sequestration (CCS) technology, oxyfuel combustion has the potential of achieving zero CO2 emissions. Also, thermal NOx emissions resulting from the use of air as oxidizer can be eliminated. However, stability is a serious issue for all combustion systems and particularly for new combustion technology that will be utilizing a different oxidizer like the O2/CO2 oxidizer mixtures in swirl-stabilized oxy-combustion. This is because any mechanism through which sporadic heat release rates arises due to equivalence ratio perturbation and/or flame-vortex interaction can lead to combustion thermo-acoustic instability. Thermo-acoustic instability in combustion system is potentially dangerous phenomena as it can lead to structural damage in the system due to excessive vibrations and heat transfer to the combustion chamber and can translate into a serious safety issue. The proposed research is aimed at studying experimentally, the thermo-acoustic instability related to oxyfuel combustion in a swirl-stabilized, non-premixed gas turbine model combustor. Our findings are expected to contribute in a positive way towards effective utilization of oxyfuel combustion technology as an eco-friendlier alternative in power generating gas turbines and other industrial burners