TY  - EJOU
AU  - Liu, Bing 
AU  - Chen, Yikun 
AU  - Liu, Huachen 
AU  - Wu, Qiao 
AU  - Wang, Minghui 
AU  - Wan, Jianlong 

TI  - Effect of Thermal Conductivity of Tube-Wall on Blow-Off Limit of a Micro-Jet Methane Diffusion Flame
T2  - Energy Engineering

PY  - 2022
VL  - 119
IS  - 2
SN  - 1546-0118

AB  - 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 (<i>λ</i><sub>s</sub>) on the operating limit of micro-jet flame. Unexpectedly, the non-monotonic blow-off limits with the increase of <i>λ</i><sub>s</sub> 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 <i>λ</i><sub>s</sub>. 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 <i>λ</i><sub>s</sub>. 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.
KW  - Micro-jet diffusion flame; thermal conductivity; blow-off limit; heat transfer; flow field

DO  - 10.32604/ee.2022.017988