JPS59142332A - Gas turbine combustor - Google Patents

Abstract

PURPOSE:To prevent a catalyst layer from being broken and its broken fragments from being scattered during operation by a structure wherein the catalyst layer is sandwiched by supporting layers made of porous substance with large high-temperature strength. CONSTITUTION:Catalyst 5, which has small high-temperature strength, is sandwiched by substances with large high-temperature strength such as porosity metal type SELMET4 and 6 in order to prevent broken catalyst from flowing in and destroying a turbine. In addition, the interior of supporting devices 7, which support said catalyst layer 5, and porosity metals 4 and 6, is cooled by circulating with cooling air so as to fully withstand against the high temperature gas flowing in a combustor.

Description

[Detailed description of the invention] The present invention relates to a combustor for a gas turbine.

In a gas turbine device, NOx is contained in its exhaust gas, and the amount of NOx emitted is always limited from the viewpoint of pollution control. In order to reduce these NOx emissions below the limit value, it is necessary to develop a combustion method that generates a small amount of NOx. Conventionally, efforts have been made to reduce the amount of NOx generated by using combustion air supply methods, but there are demands for NOx reductions that far exceed the limits that can be achieved with these methods, and expensive methods are required to meet these demands. A denitrification device will be installed. Therefore, the present invention aims to achieve low-temperature combustion using a catalyst, which is different from conventional combustion mechanisms. This catalytic combustion method has already been adopted in many other fields, but due to the special nature of gas turbine combustors, it has not yet been put into practical use and is still in the research stage.

In gas turbine combustors that utilize conventional catalytic combustion methods, the catalyst layer is unstable due to thermal shock and high temperatures, or the catalyst layer is destroyed during operation, resulting in fragments of the combustor flowing downstream of the combustor. There is a risk that it will enter the turbine and destroy the turbine blades, causing a major accident. Therefore, there is a need for a holding device for the catalyst layer portion that is free from this risk and has less pressure loss. Also,
In a gas turbine combustor, the supporting device for supporting the holding device cannot be made of metal because of the high temperature, so it must be cooled using combustion air to provide a stable and highly reliable structure.

It is an object of the present invention to provide a novel combustor for a gas turbine that satisfies the above requirements and reduces the amount of NOx emitted.

The accompanying drawing is a longitudinal sectional view of a combustor showing a preferred embodiment of the present invention.

In this combustor 3, a mixture of fuel and primary air from the burner 1 is introduced and ignited, and is combusted by the secondary air from the combustion air inlet 2. In order to achieve relatively low temperature combustion, according to the present invention, a catalyst layer 5 of ceramic or cloth catalyst is provided.

The catalyst layer 5 is inherently susceptible to thermal deformation and thermal shock caused by starting and stopping the gas turbine, and there is a high risk that the catalyst layer 5 will flow into the turbine downstream of the combustor and cause the turbine to be excited and destroyed. In the present invention, in order to eliminate these risks, as shown in the figure, a foamed metal type SELMET, 4
and 6, the catalyst 5 having low thermal strength is sandwiched between the catalysts 5 and 6 to prevent broken catalysts from flowing into the turbine and destroying the turbine. Furthermore, these catalyst layers 5 and, for example, a foamed metal 4 that holds the catalyst layers.
A support device 7 for stably supporting both the combustor 3 and 6i is directly connected to the combustor 3, and cooling air is passed through the inside of the combustor so as to sufficiently withstand the high temperature gas in the combustor.

The catalyst layer and the holding layer are free to thermally expand and contract. Furthermore, the support device has a structure that allows the catalyst layer and the holding layer to be freely replaced.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view of a preferred embodiment of the present invention.
-1・
・Burner, 2...Combustion air inlet, 3...Combustor, 4
, 6... Retaining layer, 5... Catalyst layer, 7... Supporting device.

Claims (1)

[Claims] In a gas stani bottle combustor having a catalyst layer for promoting low-temperature combustion, the catalyst layer is sandwiched between retaining layers made of a porous material with strong thermal strength, and a support device supports the catalyst layer and the retaining layer. is a gas turbine combustor that has a patented structure that is cooled by combustion air.