Research On Central Stage Fuel Injection Structure Of Coaxial Staged Combustion Chamber

In recent years,with the global climate problem becoming increasingly prominent,the control of gas turbine pollutant emissions has aroused widespread concern in academia and industry.Natural gas is an efficient,clean,resource-rich,low-carbon and environmentally friendly fuel.Natural gas-fired gas turbine have become an important development trend for gas turbine technology at home and abroad.As an effective low-emission combustion technology,coaxial staged combustion technology can adopt the aerodynamic staged combustion organization mode in which the central stage and the main stage of combustion work together to achieve high-efficiency,stable,and low-emission combustion at the wide boundary of the combustion chamber.In the coaxial staged combustor,the fuel injection and transportation characteristics of the central stage directly determine the ignition boundary of the combustion chamber and the problem of inter-flame,which is one of the important bottlenecks in the design of the coaxial staged combustor.Aiming at the above problems,this article takes a natural gas coaxial model combustion chamber as the research object and uses numerical simulation methods to carry out the following research work:(1)Based on the central stage structure of the coaxial staged combustor,the different layouts of the axial holes and oblique radial holes of the central stage are studied.The influence law of fuel distribution,and determine the more reasonable central-level structure of the hole layout scheme in the research scope of this paper,and conduct subsequent analysis.(2)Based on the determined center-stage structure under ignition conditions,the effects of different distribution methods of central-stage axial holes and oblique radial holes on the fuel distribution,temperature distribution,and combustion intermediate product distribution are analyzed,while ensuring that the total fuel quantity does not Under the premise of changes,the fuel with axial or oblique radial holes of a certain mass flow rate is distributed to the first-stage fuel holes,and the change rules of fuel distribution,temperature distribution,and combustion intermediate product distribution before and after fuel distribution are compared and analyzed.(3)Under low operating conditions,the amount of center-stage fuel is fixed,and the first-stage premixed fuel is added.The influence of different first-stage fuel amounts on the fuel-air mixing distribution,temperature distribution,and combustion characteristics is analyzed.In addition,the first-stage premix is ignited.After the fuel is discharged,the center-stage fuel is withdrawn,and the temperature distribution and the change of combustion characteristics before and after the center-stage fuel are withdrawn are compared and analyzed.