Dual Fuel Nozzle Design And Numercial Simulation Of Combustion Flow Filed

To aimed at the current power generation gas turbine on the ground which requiredburning a variety of fuels such as gaseous or liquid，the fuel supply system of gas turbine needto be refitted．The most important requirement of which is the change of the fuel nozzle．Theperformance of nozzle required will directly affect the performance of combustion chamber，such as combustion efficiency，pollutant emissions，combustion stability，temperaturedistribution，and so on．In this dissertation，concerned with a certain type of combustor used in chemicallyrecuperated gas turbine，a new type of dual fuel nozzle is designed in order to meet the needsof its individual burning liquid or gaseous fuel，or co-burning of the two fuels，to providereference for the transformation of fuel system of the power generation turbines．Learning from past experience in the design of the dual fuel nozzle and keeping thestructure of the combustor chamber and power capability invariabile，a new design of a dualfuel nozzle is discussed in the paper．With the consideration that only liquid fuel can be usedin the starting condition，it is decided to use pressure swirl atomization forms to meet therequirements of atomization of the low condition．Primarily，by using the VOF method I simulate the internal flow performance in thepressure swirl nozzle and capture the changing processes of the gas-liquid interfaceshape．Further，by changing the size of the parameters of the aspect ratio of swirl chamber，aspect ratio of the outlet section，the angle of the swirl chamber，the ratio of diameter of theswirl chamber and outlet section，the change law of the film thickness and the spray coneangle is obtained，reference design for dual fuel nozzle in the circuit is also provided．Numerical simulation of combustion flow field under the new design nozzle is made，byusing k-e turbulence model，PDF combustion model．The SIMPLE algorithm method is usedto solve the equations．Combined with the actual situation of the chemically recuperated gasturbine，the flow field in the four cases of the burning of gaseous and liquid fuel individuallyis simulated，also with co-burning of this two kinds，and burning oil with water steaminjection．The results show that: the four conditions nozzle performance to meet the designrequirements well，compared with burning oil alone，changing game-high temperature reduce burning pyrolysis gas outlet temperature uniformity better．NOx exhausted significantlyreduced，injection water vapor audience temperature is lowered，the formation of pollutants issuppressed．...