Open Access

ARTICLE

Effect of Thermal Conductivity of Tube-Wall on Blow-Off Limit of a Micro-Jet Methane Diffusion Flame

Bing Liu¹, Yikun Chen¹, Huachen Liu¹, Qiao Wu¹, Minghui Wang¹, Jianlong Wan^2,*

1 China Tobacco Hubei Industrial LLC, Wuhan, 430040, China
2 School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China

* Corresponding Author: Jianlong Wan. Email:

(This article belongs to the Special Issue: Advanced Materials and Technologies for Sustainable Energy)

Energy Engineering 2022, 119(2), 815-826. https://doi.org/10.32604/ee.2022.017988

Received 21 June 2021; Accepted 16 July 2021; Issue published 24 January 2022

Abstract

The operating range of the flow rate or flow velocity for the micro-jet flame is quite wide, which can be used as the heat source. In order to optimize the micro-jet tube combustor in terms of the solid material, the present paper numerically investigates the impact of thermal conductivity (λ_s) on the operating limit of micro-jet flame. Unexpectedly, the non-monotonic blow-off limits with the increase of λ_s is found, and the corresponding generation mechanisms are analyzed in terms of the thermal coupling effect, flow field, and strain effect. At first, the lower preheating temperature of the fuel and larger heat loss amount to the environment lead to a larger blow-off limit at a larger λ_s. After that, the smaller local flow velocity in the vicinity of flame root and smaller strain effect slightly increase the blow-off limit with the continuously increasing λ_s. Therefore, it is deduced that the applied performance of micro-jet combustor with a smaller thermal conductivity is better in terms of the blow-off limit.

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Keywords

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