The Study Of The Performance Of Premixer In Premixed Combustor

Gas turbine is becoming high-powered and high thrust-weight ratio, combustor inlettemperature, inlet pressure and temperature rise are continually increasing. On the other hand,due to the environmental protection requirements, much more harsh conditions are presentedto gas turbine engine based. So it is becoming a hot topic to reduce the pollutant emission ofgas turbine combustor in recent decades, while many kinds of new concept and new structurecombustor are emerging.Premixed combustion could reduce pollutant emission such as nitrous oxides and carbonmonoxide, and shorten the size of the combustor. So the premixed combustion exhibits betterdevelopment prospect than the traditional combustion. Premixed combustion is mixing fuelwith air in premixer prior to in combustor, so the premixer structure have an influence onpremixed combustion. Due to the premixed combustor characteristics, there are no specificdesign principle and standard for the premixer. The influence of equivalence ratio, swirler,premixer length and the emission angle of the fuel nozzle on premixed combustor wasinvestigated by the computational fluid dynamics software under certain boundary conditions.The study results indicate: for the radial swirler, when the vane installation was60themixture propagates velocity along boundary layers was faster than the other three vanesinstallation angle, it can better avoid flashback. For the axial swirler, the flow rate alongboundary layers is in proportion to the vane installation angle of swirler in premixer. With theincrease of the premixer length, the mixture of fuel and air is easily flashback in the premixer.In the combustion zone, the combustor temperature rises along with the rises of equivalenceratio, so reducing equivalence ratio is appropriately helpful to reduce the combustortemperature.