Combustor

Abstract

A combustor which is compact and generates a reduced amount of NOx. A combustor (1) is equipped with a pilot nozzle (21) mounted in the axis of the combustor (1) and performing diffusive combustion, main nozzles (22) mounted at circumferentially spaced intervals on the outer peripheral side of the pilot nozzle (21) and performing premixed combustion, an inner tube (2a) surrounding the pilot nozzle (21) and the main nozzles (22), and an outer tube substantially coaxially and externally surrounding the inner tube (2a) and forming a compressed-air flow path (6) between the inner peripheral surface of the outer tube and the outer peripheral surface of the inner tube. The direction of flow of compressed air flowing in the compressed-air flow path (6) is substantially reversed at an end of the inner tube (2a) and introduced into the pilot nozzle (21). A flow rate regulating section is provided in the compressed air flow path (6), and the flow rate regulating section increases the flow rate of the compressed air in that portion of the flow path which is on the inner peripheral side of the combustor (1) to a level greater than the flow rate of the compressed air in that portion of the flow path which is on the outer peripheral side. A flow regulating plate (51) having holes (55, 56) therein can be used as the flow rate regulating section.

Description

technical field [0001] The present invention relates to a combustor of a steam turbine, and more particularly, to a combustor having a structure to reduce deviation and turbulence of the air flow flowing therein. Background technique [0002] For the subject of reducing NOx in a steam turbine combustor, it is very important not to generate a local high fuel concentration by controlling the fuel distribution, and furthermore, it is necessary to make the fuel concentration uniform. Therefore, the increase in the amount of main air through which most of the fuel passes and its homogenization are very important. [0003] Conventionally, there has been disclosed a burner that rotates mainstream air from a vehicle cabin by 180 degrees to guide the mainstream air to a main premixing nozzle (for example, refer to Patent Document 1). In such a burner, in order to eliminate the flow unevenness such as separation accompanying the flow, a rectifying plate is provided at the inlet, and ...

AI Technical Summary

Problems solved by technology

[0005] However, such a conventional structure leads to an increase in weight and cost due to an increase in the length of the combustor, and also complicates the turning part, so it is ineffective for downsizing the combustor.

On the other hand, when the distance from the turning part to the fuel mixing part is shortened, there is a problem of an increase in the amount of NOx produced along with the deterioration of the bias of the air distribution as an incompatibility.

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