Abstract:In order to compare the influence of environmental temperature on combustion stability and NOx emission under different combustion modes of a gas turbine， taking a heavy gas turbine combustor as the research object，the numerical models of full-scale combustor for the diffusion and premixed combustion were established. The combustion stability and NOx emissions of the multi-swirl nozzle combustor were numerically calculated. The results showthat for the diffusion combustion，the high frequency pulsation in the combustor is enhanced after the environmental temperature rises， and the combustion stability is deteriorated. For the premixed combustion，the increase of the environmental temperature is beneficial to improve the stability of combustion; In the diffusion combustion mode，the temperature in the downstream recirculation zone of the combustor fuel nozzle is the highest，and the NOx production is also the largest. In the premixed combustion mode， the temperature distribution in the combustor head is relatively uniform，the NOx formation in the combustor is mainly concentrated in the trapped vortex recirculation zone and the middle and downstream of the combustor，the NOx formation in the downstream recirculation zone of the fuel nozzle is small; As the environmental temperature increases，the amount of NOx generated in the combustor increases under both diffusion and premixed combustion. The research results provide a reference for guiding the operation of gas turbines.