A dry low-pollution combustor double radial swirl nozzle for a gas turbine

Abstract

The invention discloses a dry low-pollution double-radial swirl nozzle of a combustion chamber for a gas turbine, and belongs to the technical field of the gas turbines. By means of the swirl nozzle,the problems that an existing premixed combustion chamber of the gas turbine is unstable in combustion, high in NOx pollution emission at low load, poor in adjustability, nonuniform in radial distribution of speed and fuel concentration, large in axial size and difficulty in processing swirl blades are solved. The swirl nozzle is characterized in that three pipe fittings of the double-radial swirlnozzle are arranged on the left side of an inner swirl assembly and are respectively connected with the inner swirl assembly; an outer swirl assembly is arranged on the right side of the inner swirlassembly; air inlet areas and swirling numbers of the inner swirl assembly are different from those of the outer swirl assembly; a diffusive combustion / cooling assembly is arranged between the inner swirl assembly and the outer swirl assembly; and a central sweeping piece is arranged in the center of the inner swirl assembly. By means of the double-radial swirl nozzle, the axial dimension of a premixing combustion nozzle is shortened, a premixing space is subdivided, the premixing uniformity is increased, the combustion is stable at low load, the pollution emission of the combustion chamber isreduced, and the structure is simple.

Description

technical field [0001] The invention relates to a gas turbine combustion nozzle, in particular to a double radial swirl nozzle for a dry low-pollution combustion chamber for a gas turbine, belonging to the technical field of gas turbines. Background technique [0002] With the increasingly stringent environmental protection requirements, the pollution emission of gas turbines is becoming more and more strict at home and abroad, especially for NO in gas turbine flue gas. X There are clear requirements for emissions. When using natural gas as fuel, the Chinese national standard GB13223-2011 requires NO X Emission concentration≤50mg / Nm 3 (@15%O 2 ), Beijing local standard DB11 / 847-2011 requires NO X Emission concentration≤30mg / Nm 3 (@15%O 2 ), Shenzhen local regulations require NO X Emission concentration≤15mg / Nm 3 (@15%O 2 ), thus reducing NO X Pollutant emissions are very important for gas turbines. [0003] At present, there are two main ways to achieve low polluti...

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Problems solved by technology

[0003] At present, there are two main ways to achieve low pollution emissions from gas turbines: First, inject diluent, usually water or water vapor, into the nozzle of the gas turbine combustor to reduce the temperature of the combustion area and reduce NO X However, it will cause fouling of the combustion chamber and turbine blades, reduce the efficiency of the unit, and shorten the life of high-temperature components. out, then mixed in the mixing section, and then enters the combustion chamber for combustion to form a stable flow field and temperature field, but the axial dimension is relatively large, and the swirl blades are difficult to process. In addition, due to the coaxial structure, the speed and fuel The radial distribution of concentration is not easy to be uniform, and the center generally arranges diffusion fuel nozzles, and NO X Pollutant generation is higher

[0004] Especially in the application of small and medium-sized and micro gas turbines, the structural size is also a very important parameter. The axial premixing structure requires a long mixing section to ensure the uniformity of mixing, or a very large number of micro nozzle structures to ensure the uniformity of mixing , the application is more difficult and the cost is higher

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