Study Of The Effect Of Lean Oxygen On The Combustion Characteristics Of Model Combustion Chambers

Gas turbines are the jewel in the crown of industry and have a wide range of applications in naval power,industrial power generation and oil and gas transmission,but they also face difficulties in controlling NO_x emissions.Flue gas recirculation technology is a technology that circulates part of the exhaust gas back to the gas turbine to participate in a new cycle,which can significantly reduce the temperature in the combustion chamber of the gas turbine and thus reduce NO_x emissions.However,as part of the flue gas is recycled back to the combustion chamber,the oxygen content of the combustion chamber air will be significantly reduced and the content of inert gas will be greatly increased,resulting in a lower chemical reaction rate in the combustion chamber,which may cause unstable combustion or even flameout in the gas turbine combustion chamber,which poses a challenge to the efficient and stable combustion organization of the gas turbine combustion chamber with flue gas recirculation technology.Therefore,it is necessary to study the influence of oxygen content on the combustion performance,flameout characteristics and stability of gas turbine combustion chamber under wide working conditions,which can lay the foundation for expanding the flameout boundary and stable combustion boundary of gas turbine combustion chamber under poor oxygen conditions.In this paper,the geometry of the gas turbine model combustion chamber is designed,and based on the designed gas turbine model combustion chamber,the effect of oxygen content on the combustion characteristics,flameout characteristics and combustion stability of the gas turbine model combustion chamber at different incoming flow rates,pressures and temperatures is studied,and the effect of oxygen content on the combustion characteristics,flameout boundary and stability of the gas turbine model combustion chamber at different incoming flow parameters is obtained.The main work is as follows.(1)Based on the design method of gas turbine combustion chamber,the preliminary design of the geometric structure of gas turbine model combustion flame cylinder,cyclone and venturi was completed under the given design conditions,and the combustion performance parameters of the designed model combustion chamber were calculated by using three-dimensional numerical simulation method to verify that the flow field structure of the model combustion chamber is reasonable and meets the requirements of the combustion chamber performance,which can be used for the subsequent development of the effect of oxygen content on the combustion performance of gas turbine model combustion chamber under different operating conditions.(2)Based on the design conditions,the model combustion chamber is designed to meet the requirements of combustion chamber performance.(2)Based on the design conditions,a wide parameter numerical simulation study of the model combustion chamber is carried out,and the effect of oxygen content on the combustion characteristics of the model combustion chamber at different operating pressures,incoming flow rates and temperatures is analyzed by the control variable method.(3)The prediction of the depleted oil flameout limit of the model combustion chamber was carried out,and the response trends of the depleted oil flameout limit to different parameters such as oxygen content,operating pressure,incoming flow rate and temperature were obtained.And for the dynamic stability of combustion,a transient numerical simulation study was conducted using large eddy simulation to investigate the structure of vortex nucleus,component concentration,and the time-based changes of heat release pulsation,pressure pulsation,and velocity pulsation to obtain the intrinsic connection of dynamic stability of combustion.