4.7 Article

Hydrogen substitution of natural-gas in premixed burners and implications for blow-off and flashback limits

Journal

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
Volume 47, Issue 77, Pages 33067-33081

Publisher

PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.ijhydene.2022.07.066

Keywords

Hydrogen substitution; Premixed combustion; Lean blow -off; Flashback

Funding

  1. European Union
  2. European Research Council (ERC) [952181]
  3. Center of Excellence in Combustion (COEC)
  4. [832248]

Ask authors/readers for more resources

This study investigates the effects of hydrogen addition on the stability and flashback occurrence of two different multi-perforated premixed burners designed for natural gas. The results show that hydrogen addition increases the blow off resistance of the burners, but also raises the risk of flashback. It is found that the occurrence of flashback is closely related to the surface temperature of the burners.
Two multi-perforated premixed burners, designed for natural gas, are fueled with increasing hydrogen content to assess the limits of H2 substitution and investigate potential risks associated to it. The burners feature a different design, which affects flame stabilization and heat exchange between the fresh mixture and the hot burner walls. First, results are presented by means of stability maps that were collected at constant power and over a wide range of equivalence ratio, from pure methane-air to pure hydrogen-air mixtures. The impact of hydrogen addition on blow-off and flashback limits is then analyzed. On one side, it is observed that hydrogen addition increases blow off resistance, extending the operating range towards ultra-lean conditions. On the other side, hydrogen raises the thermal load on the burner favoring flashback. It is shown that the competition between the bulk velocity at the burner outlet and the laminar burning velocity is not a reliable parameter to predict flashback occurrence, while the thermal state of the burner represents a determining factor. An analysis of the thermal transient reveals a strict correspondence between the onset of flashback for a given mixture composition and the burner surface temperature. Results highlight the challenges linked to the design of fuel-flexible systems, pointing out practical limits of H2 substitution in burners designed for operation with natural gas.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.7
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available