JPH07190365A - Gas-turbine combustor - Google Patents

Abstract

PURPOSE:To provide a gas turbine combustor whereby the amount of combus tion air can be increased even if the amount of NOx to be generated is in creased by rising of the outlet temperature of the gas-turbine combustor, thereby the amount of NOx to be generated can be sufficiently decreased, and the wall surface of an inner tube for the conbustor can be cooled efficiently and sufficiently with a small amount of cooling air. CONSTITUTION:In a gas-turbine combustor having an inner tube 3 therefor in which fuel is burned and having an external wall 1 or a flow sleeve 2 in which the 'inner tube 3 is placed, the upstream side of the inner tube 3 at which side the temperature of burnt gas is higher is formed in film-cooled structure or in impingement-cooled structure wherein wall surface-cooling air flows in the inside of the combustor. On the other hand, the downstream side of the inner tube is formed in convection-cooled structure wherein the wall surface- cooling air does not flow in the inside of the combustor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine combustor applied to a gas turbine plant, a combined plant, or the like, and particularly, to reduce the NOx concentration contained in the exhaust gas of a gas turbine, thereby reducing the amount of cooling. The present invention relates to a gas turbine combustor capable of cooling with an air amount.

[0002]

2. Description of the Related Art In recent years, in order to improve the thermal efficiency of a turbine, the turbine inlet temperature, that is, the outlet temperature of a gas turbine combustor has been increased. However, when the outlet temperature of the gas turbine combustor rises, NOx
The concentration of (nitrogen oxide) also increases, and as the outlet temperature rises, the cooling air for cooling the wall surface of the combustor inner cylinder also increases.

The main cause of NOx generation in the gas turbine combustor is the local high temperature of the combustion gas in the gas turbine combustor.

As a method of reducing NOx generated, there are a two-stage premixed combustion method, a method of injecting water or steam, and the like.

In the two-stage premixed combustion system, the first-stage combustion region upstream of the combustion chamber is used as a high-temperature gas region to form a stable flame using a small amount of the first-stage fuel, and it is difficult for the high-temperature combustion gas to combust. This is a method of stably burning the lean premixed air-fuel mixture in the second stage combustion region to prevent the generation of a locally high temperature portion and suppress the generation of NOx.

A conventional device using the two-stage premixed combustion system uses fuel for introducing a lean premixed mixture into the second stage combustion region, as described in, for example, Japanese Patent Laid-Open No. 61-105029. It is composed of a nozzle to be introduced, a swirler to introduce air, a tubular premix evaporation unit for premixing fuel and air introduced from the nozzle and swirler, and the like.

The fuel sprayed from the nozzle is mixed with the swirling air in the swirler, the fuel evaporates toward the downstream side, and is further well mixed with the air, and the combustion is the exit of the premixing preevaporating section. It is introduced into the second stage combustion zone of the chamber and burned.

[0008]

However, as the outlet temperature rises, the amount of cooling air for cooling the wall surface used for the inner cylinder of the combustor must be increased, so that the combustion air decreases,
As a result, there is a possibility that a problem may occur with respect to the reduction of the NOx generation amount.

Further, if the combustion air is increased in order to reduce the NOx generation amount, there is a possibility that a problem may occur in the wall surface cooling of the combustor inner cylinder.

The present invention has been made in view of the above circumstances, in which the outlet temperature of the gas turbine combustor becomes high and N
Even if the amount of Ox generated increases, the amount of combustion air can be increased, whereby a sufficient reduction of the amount of NOx generated can be achieved, and the cooling of the wall surface of the inner cylinder of the combustor reduces the amount of cooling air. It is an object of the present invention to provide a gas turbine combustor that can be efficiently and sufficiently achieved.

[0011]

In the combustor inner cylinder, a film cooling structure or impingement cooling in which wall surface cooling air flows into the combustor is provided upstream of the combustor inner cylinder having a high combustion gas temperature. This is achieved by adopting a convection cooling structure in which wall surface cooling air does not flow into the combustor on the downstream side of the combustor inner cylinder.

Further, in a combustor having a combustor inner cylinder and a flow sleeve which encloses the combustor inner cylinder, a film cooling structure or impingement structure in which wall surface cooling air flows into the combustor inside the combustor inner cylinder upstream side. It is also possible to achieve this by using an ment cooling structure and an impingement cooling structure by a cooling hole formed in the flow sleeve on the downstream side of the combustor inner cylinder to prevent the wall surface cooling air from flowing into the combustor.

[0013]

The inner cylinder of the combustor is divided into the upstream side and the downstream side, and the upstream side where the combustion gas temperature is high performs wall surface cooling by using a cooling structure in which air flows into the inside, and the downstream side flows into the inside. By using the cooling structure that does not include the soundness of the combustor inner cylinder metal temperature, a small amount of cooling air can be maintained.

As a result, the amount of combustion air can be increased, and the achievement of the ultra lean combustion condition can be promoted.
The amount of Ox generated can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas turbine combustor according to a first embodiment of the present invention will be described below with reference to FIG.

In this embodiment, the combustor inner cylinder 3 is housed in the outer wall 1 or the flow sleeve 2. A combustion chamber 4 is formed in the combustor inner cylinder 3, and an annular flow path 5 is formed between the combustor inner cylinder 3 and the outer wall 1 or the flow sleeve 2, and air flows through the flow path 5. You will be guided.

Inside the combustion chamber 4, there is a first-stage combustion zone 6 having a high combustion gas temperature on the upstream side of the inner cylinder, and a second-stage combustion zone 7 on the downstream side of the inner cylinder, which is the downstream side of the first-stage combustion zone 6. It is divided into and.

For cooling the wall surface of the first-stage combustion zone 6 on the upstream side of the inner cylinder, a cooling structure in which cooling air flows into the inner cylinder 3 of the combustor through the inflow hole 6a and is consumed, that is, a film cooling structure or impingement A cooling structure or the like is used.

For cooling the wall surface of the second-stage combustion zone 7 on the downstream side of the inner cylinder, a cooling structure in which cooling air does not flow into the inner cylinder of the combustor, that is, the inner cylinder 3 of the combustor and the outer wall 1 or the flow sleeve 2 is provided. A convection cooling structure is used that cools through the annular channel 5 between.

Explaining the flow of air, the air is guided through an annular flow path 5 between the combustor inner cylinder 3 and the outer wall 1 or the flow sleeve 2, and is first located downstream of the combustor inner cylinder 3. The second combustion zone 7 is cooled on the wall surface and moved to the upstream side.

On the upstream side, part of the air is consumed for cooling the wall surface of the first stage combustion zone 6, and most of the remaining air is used as combustion air.

With such a structure, the wall surface can be cooled with the consumption of a small amount of cooling air, and the soundness of the metal temperature in the combustor inner cylinder can be maintained. As a result, the amount of combustion air can be increased. it can. Then, the achievement of the ultra-lean combustion condition is promoted, whereby the NOx generation amount can be reduced.

FIG. 2 shows a second embodiment.

At the downstream end of the combustor inner cylinder 3, there is a possibility that the metal temperature may rise. Therefore, in the present embodiment, in order to increase the soundness of the metal temperature of the combustor inner cylinder 3, an opening 9a is formed in a portion 9 near the spring seal 8 installed at the downstream end of the combustor inner cylinder 3. As a result, a wall surface cooling structure in which the cooling air flows into the combustor inner cylinder 3 is provided, the downstream end of the combustor inner cylinder 3 is effectively cooled, and a problem that the metal temperature rises is prevented.

FIGS. 3, 4, 5, and 6 show the third, fourth, fifth, and sixth embodiments, respectively.

In these embodiments, for cooling the wall surface of the second stage combustion zone 7 on the downstream side of the inner cylinder, a cooling structure in which cooling air does not flow into the inner cylinder of the combustor, that is, the inner cylinder 3 of the combustor and the outer wall 1 or the flow. A convection cooling structure for cooling through the annular flow path 5 between the sleeve 2 and the sleeve 2 is used.

In the third embodiment shown in FIG. 3, the combustor inner cylinder 3
A large number of grooves 11 are formed along the axial direction on the downstream side outer peripheral portion 10.

Further, in the fourth embodiment shown in FIG. 4, a large number of grooves 11 are formed along the circumferential axis direction.

With such a structure, the heat transfer area is increased on the cooling air side, and cooling is performed strongly.

In the fifth embodiment shown in FIG. 5, the combustor inner cylinder 3
A large number of grooves 11 are formed along the circumferential direction of the downstream side outer peripheral portion 10, and a large number of small projections 12 are provided in the groove 11 to provide a composite structure.

As a result, the heat transfer area can be increased and the heat transfer coefficient can be improved, and strong cooling can be achieved.

In the sixth embodiment shown in FIG. 6, the combustor inner cylinder 3
The downstream side of the structure has a thin plate structure, and in order to obtain the effect of increasing the heat transfer area and the effect of reducing thermal stress, a reinforcing material 13 such as a rib is further provided on the outer peripheral portion 10.

By installing a cooling accelerator in the outer peripheral portion 10 on the downstream side of the inner cylinder, the soundness of the metal temperature of the combustor inner cylinder on the downstream side can be further strongly increased. As a result, the achievement of the ultra lean combustion condition is further effectively promoted.

FIG. 7 shows a seventh embodiment. The combustor of this embodiment has a flow sleeve 2 including a combustor inner cylinder 3.

In this case, the wall cooling of the first stage combustion zone 6 on the upstream side of the combustor inner cylinder 3 is performed by a film cooling structure or impingement cooling in which cooling air flows into the combustor through the inflow holes 6a. It has a structure.

Further, for the wall surface cooling of the second stage combustion zone 7 on the downstream side of the combustor inner cylinder 3, the impingement cooling structure by the cooling holes 14 formed in the flow sleeve 2 is used, and the wall surface cooling air is supplied. It has a cooling structure that does not flow into the combustor.

As a result, the soundness of the temperature of the metal in the inner cylinder of the combustor on the downstream side can be further strongly increased, the achievement of the ultra-lean combustion condition can be more effectively promoted, and the NOx generation amount can be further reduced. be able to.

The present invention is not limited to the above-described embodiments, and various modifications and applications can be made such as combining the configurations of the embodiments shown in FIGS. 2, 3, 4, 5, and 6 with each other. It is possible.

Further, the gas turbine combustor of the present invention can be widely applied to various types of gas turbine plants, combined cycle power plants and the like.

[0040]

As described in detail in the above embodiments, according to the present invention, the outlet temperature of the gas turbine combustor becomes high,
Even if the NOx generation amount increases, wall surface cooling can be performed by consuming a small amount of cooling air, and the soundness of the combustor inner cylinder metal temperature can be maintained.

Therefore, the amount of combustion air can be increased, and the achievement of the ultra lean combustion condition can be promoted.
This makes it possible to sufficiently reduce the amount of NOx generated and to sufficiently improve the gas turbine efficiency.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a gas turbine combustor according to an embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a fifth embodiment of the present invention.

FIG. 6 is a diagram showing a sixth embodiment of the present invention.

FIG. 7 is a diagram showing a seventh embodiment of the present invention.

[Explanation of symbols]

 1 Outer Wall 2 Flow Sleeve 3 Combustor Inner Cylinder 4 Combustor Chamber 5 Flow Path 6 First Stage Combustion Area 6a Inlet Hole 7 Second Stage Combustion Area 8 Spring Seal 9 Spring Seal Adjacent Area 9a Opening 10 Combustor Inner Cylinder Downstream Outer Side Part 11 Groove 12 Small protrusion 13 Reinforcement material 14 Air hole

Claims (12)

[Claims] 1. A gas turbine combustor having a combustor inner cylinder in which fuel burns inside, and an outer wall or a flow sleeve enclosing the combustor inner cylinder, wherein the upstream side of the combustor inner cylinder having a high combustion gas temperature is Gas having a film cooling structure or impingement cooling structure in which wall cooling air flows into the combustor, and a convection cooling structure in which wall cooling air does not flow into the combustor inside the combustor inner cylinder downstream side. Turbine combustor. 2. The gas turbine combustor according to claim 1, wherein the upstream portion of the spring seal at the downstream end of the combustor inner cylinder has a film cooling structure in which wall surface cooling air flows into the combustor. Gas turbine combustor. 3. The gas turbine combustor according to claim 1, wherein a large number of grooves are provided on the downstream side of the combustor inner cylinder along the axial direction. 4. The gas turbine combustor according to claim 1, wherein a large number of grooves are provided in the combustor inner cylinder downstream side along the circumferential direction. 5. The gas turbine combustor according to claim 1, wherein a large number of grooves are provided along the circumferential direction on the downstream side of the combustor inner cylinder, and a large number of small projections are provided in the grooves. And a gas turbine combustor. 6. The gas turbine combustor according to claim 1, wherein a downstream side of the combustor inner cylinder has a thin plate structure, and the thin plate structure is reinforced by a reinforcing material. 7. A gas turbine combustor having a combustor inner cylinder in which fuel burns inside and a flow sleeve containing the combustor inner cylinder, wherein wall surface cooling air is provided on the upstream side of the combustor inner cylinder. A film cooling structure or impingement cooling structure that flows into the inside is used, and an impingement cooling structure is used on the downstream side of the combustor inner cylinder by a cooling hole formed in the flow sleeve to prevent wall surface cooling air from flowing into the inside of the combustor. A gas turbine combustor characterized by having a structure. 8. The gas turbine combustor according to claim 7, wherein a film cooling structure for allowing wall surface cooling air to flow into the combustor is provided at an upstream portion of a spring seal at a downstream end of the combustor inner cylinder. Turbine combustor. 9. The gas turbine combustor according to claim 7, wherein a large number of grooves are provided in the combustor inner cylinder downstream side along the axial direction. 10. The gas turbine combustor according to claim 7, wherein a large number of grooves are provided in the combustor inner cylinder downstream side along the circumferential direction. 11. The gas turbine combustor according to claim 7, wherein a large number of grooves are provided along the circumferential direction on the downstream side of the combustor inner cylinder, and a large number of small projections are provided in the grooves. And a gas turbine combustor. 12. The gas turbine combustor according to claim 7, wherein the downstream side of the combustor inner cylinder has a thin plate structure, and the thin plate structure is reinforced by a reinforcing material.