Combustion of alternative fuels in vortex trapped combustor

Trapped vortex combustor represents an efficient and compact combustor for flame stability. Combustion stability is achieved through the use of cavities in which recirculation zones of hot products generated by the direct injection of fuel and air are created and acting as a continuous source of ignition for the incoming main fuel–air stream. Computational Fluid Dynamics analysis was performed in this study to test the combustion performance and emissions from the vortex trapped combustor when natural gas fuel (methane) is replaced with renewable and alternative fuels such as hydrogen and synthetic gas (syngas). The flame temperature, the flow field, and species concentrations inside the Vortex Trapped Combustor were obtained. The results show that hydrogen enriched hydrocarbon fuels combustion will result in more energy, higher temperature (14% increase when methane is replaced with hydrogen fuels) and NOx emissions, and lower CO2 emissions (50% decrease when methane is replaced with methane/hydrogen mixture with 75% hydrogen fraction). The NOx emission increases when the fraction of hydrogen increases for methane/hydrogen fuel mixture. The results also show that the flame for methane combustion fuel is located in the primary vortex region but it is shifted to the secondary vortex region for hydrogen combustion.

► We model the combustion of alternative fuels in trapped vortex combustor (TVC).
► We test syngas and hydrogen/hydrocarbon mixture fuels.
► We examine the change in combustion performance and emissions of TVC combustor.
► Increasing the hydrogen content of the fuel will increase the temperature and NOx emissions.
► A high combustor efficiency is obtained for fuels with different compositions and LHV.