436 / 2018-12-26 17:12:12

CFD study of multi-burner arrangement for partially premix combustion system

multi-burner arrangement, partially premix combustion, swirl stabilized burner

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The premix combustion system fulfills the low emission gas turbine development trend. In the meantime, to pursuit the mixing target, the single injector size would limit the burner diameter would not go larger. Therefore, the combination of multi fuel nozzles is widely used in middle range and heavy duty gas turbine combustors. For cost reduction purpose for the commercial system, it is easier to standardize the single burner production line and using same burner with different arrangements to get to the target of power.
The underlying physical mechanism inside such type of combustors is the flame-to-flame interaction process. In this paper, the distance and arrangement between one type of swirl burner is studied using steady RANS for patterns viewing. This swirl burner has been designed to fit in current lab scale test rig. The designed operating condition is partially premixed between pure methane and air under atmospheric condition. The way to stabilized the flame is aero dynamic type only, which is using center recirculation zone generated by swirl flow.
The combination variants are:
1) same direction rotation between two burners;
2) counter rotating between two burners;
3) Staggered arrangement between three burners;
4) aside arrangement between three burners.
The dynamical characteristics of the flame-to-flame system varies at different configuration in this paper by compressible LES simulation. The purpose is to check if the following phenomena existing in the confined-flame domain:
1) flame jumping in the same phase;
2) flame jumping in 90-degree phase angle;
3) no flame jumping.
The expected results could present the instability caused by two flame interaction. Finally, the qualitative design principles are shown for developing a novel combustor development process.