The role of hydrogen addition on the structure and stability of hydrocarbon flames in a JHC burner

Abstract

The role of hydrogen addition on the structure of the Moderate or Intense Low oxygen Dilution (MILD) combustion regime is examined using a combination of experimental and laminar flame calculations. Laser diagnostic imaging is used to simultaneously reveal the in-situ distribution of the hydroxyl radical (OH), formaldehyde (H2CO), and temperature using the Jet in Hot Coflow (JHC) burner. Hydrogen addition to the primary fuel was found necessary to stabilise the flame in the experimental burner. Further to the role of hydrogen in the stabilisation of the flames, strained laminar flame calculations reveal that hydrogen addition also leads to a similarisation of the reaction zone for different primary fuel types. The independence of the reaction zone structure with H2 addition suggests that a wide variety of fuels may be useable for achieving MILD combustion.