Lean Premixed Combustion Tempering Characteristics Of Study

The advantage of Lean-fuel premixed combustion is to reduce the NOx emission of gas turbine, in which a trouble we have to face is that the flame is prone to flashback to upstream under the low or high operation condition that reduce the operating stability of the gas turbine. Considering there exist large amount of hydrogen gas in medium or low-heat-value coal gas supplying gas turbine to combust in IGCC, problem of flashback is arising in such kind of fuel containing hydrogen. So, character of the V-shaped flame's flashback is investigated by the method of numerical simulation and experiment, the same as which research is carried out on Cone-shaped flame stabilized on a ring in premixed gas containing methane.Firstly, numerical simulation is conducted to predict the phenomena of flashback and some calculations are used to validate the models used to simulate the process of flashback and the turbulent flow.Secondly, these validated models are employed to predict the flashback limit in methane premixed combustion and the result is compared with the test data in quantity and leads to a conclusion: Equivalent Ratio is directly proportional to flashback velocity in methane Cone-shaped flame and the highest flash back velocity will appear when the value of ER is approached to 1; moreover, a further investigation is conducted by numerical simulation and experiment with a co-axial jet introduced into the original flow field. Results show co-flow jet has ability to prevent flashback from talking place to a certain extent, beyond which flashback will become easier to happen; besides, path of the flashback will shift from side wall to flame center with the co-axial flow's velocity increased.Finally, both numerical simulation and experiment research are carried out to investigate...