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The Effect of Inlet Velocity on CH 4 Catalytic Combustion Behavior with H 2 Addition in a Microchannel Combustor
Author(s) -
Yan Yunfei,
Xu Qingyun,
Tang Weimin,
Huang Qiao,
Zhang Li,
Li Lixian,
Yang Zhongqing
Publication year - 2017
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201600766
Subject(s) - methane , hydrogen , combustor , inlet , catalytic combustion , combustion , chemistry , catalysis , oxygen , microchannel , analytical chemistry (journal) , materials science , organic chemistry , nanotechnology , mechanical engineering , engineering
The characteristics of premixed methane/air combustion in a microchannel with a Pt catalyst were examined and the effect of inlet velocity on catalytic methane combustion with hydrogen addition was investigated numerically. It is shown that appropriate hydrogen addition can expand the extinction limits, particularly the upper extinction limit of the inlet velocity, and increase methane conversion at higher inlet velocities. However, it is proved that methane conversion at an equivalent ratio of 0.8 decreased with hydrogen addition when inlet velocity was lower than 0.36 m s −1 . The heat released in the hydrogen–oxygen reaction increased the wall temperature, which resulted in the adsorption–desorption equilibrium of oxygen shifting towards desorption as Pt(s) coverage increased and O(s) coverage decreased. With the same amount of hydrogen added, the changes in wall temperature that reflected the thermal effects of hydrogen were more obvious at higher inlet velocities, which improved methane conversion. If the heat released by hydrogen was neglected, the competitive consumption of oxygen, which demonstrates the chemical effect of hydrogen, was more significant at lower inlet velocities, which inhibited methane conversion.