Dry type low-nitrogen staged combustion system for isolating diffusion combustion flame surface

Abstract

The invention discloses a dry type low-nitrogen staged combustion system for isolating a diffusion combustion flame surface. The dry type low-nitrogen staged combustion system comprises a combustion chamber, a purge gas channel, a diffusion combustion fuel channel, a diffusion combustion isolation gas main channel, a premixed combustion fuel channel and a premixed combustion air channel, wherein the purge gas channel, the diffusion combustion fuel channel, the diffusion combustion isolation gas main channel, the premixed combustion fuel channel and the premixed combustion air channel communicate with the combustion chamber and are sequentially arranged from inside to outside; a premixed channel cyclone is arranged in the premixed combustion air channel; the premixed combustion fuel channelcommunicates with a premixed cavity through the premixed channel cyclone; the diffusion combustion isolation gas main channel is divided into two paths on the downstream portion of a premixed combustion fuel channel stop partition plate, one path is a diffusion combustion isolation gas main channel, and the other path is a diffusion combustion isolation gas sub-channel communicating with the diffusion combustion isolation gas main channel through an open hole; and a diffusion combustion fuel cyclone is arranged at the tail end of the diffusion combustion fuel channel. According to the dry type low-nitrogen staged combustion system, N2 in premixed combustion air can be isolated from the diffusion combustion flame surface, NOx emission is reduced, and the problem that combustion instabilityis likely to happen to lean-burn premixed combustion of an existing gas turbine is solved.

Description

technical field [0001] The invention relates to a dry-type low-nitrogen staged combustion system, in particular to a dry-type low-nitrogen staged combustion system for isolating a diffusion combustion flame surface. Background technique [0002] Diffusion combustion and premixed combustion are two commonly used combustion methods for gaseous fuels in gas turbines. Diffusion combustion refers to the combustion controlled by mixed diffusion factors. Fuel and air enter the combustion chamber separately, while mixing and burning. It is characterized by high combustion flame surface temperature and good flame stability, but high NOx emissions. Premixed combustion means that before the fuel is burned, the fuel and air are fully mixed into a combustible mixture in the nozzle premixer, and then ignited and burned in the combustion chamber. The advantage is that the combustion temperature can be lower than the theoretical combustion by controlling the mixing ratio. temperature, ther...

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Problems solved by technology

[0004] In order to improve the operating safety of gas turbines using lean-burn premixed combustion and solve the problem of unstable combustion in lean-burn premixed combustion, the invention provides a dry low-nitrogen staged combustion system that isolates the flame surface of diffused combustion

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