JPH0133646B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention effectively cools a part of the air compressed by a gas turbine compressor using spray water injected from an injection valve, and then cools a part of the air compressed by a gas turbine compressor. This relates to the improvement of gas turbines used as cooling air.

[Prior art]

In recent years, in order to improve the performance and output of gas turbines, the gas temperature used in gas turbines has been increasing.

However, the turbine blades of a gas turbine are
In order to maintain its strength, it is necessary to maintain the temperature below a certain level, and a method of cooling the turbine blades is used as a means for this purpose.

To cool the turbine blades, part of the air compressed by the compressor is guided into the turbine blades as cooling air, and film cooling, impingement cooling, convection cooling, etc. are performed. In order to keep the turbine blades below a certain temperature, it is necessary to increase as the temperature of the gas used rises.

However, the increase in the amount of cooling air used increases the power required to compress the cooling air, and
There is a problem in that an increase in the amount of cooling air mixed with the mainstream gas causes a decrease in average gas temperature, leading to a decrease in gas turbine cycle efficiency.

In addition, since the cooling air uses air compressed by the compressor driven by the gas turbine, the temperature is lower than that of the combustion gas, but as the output of the gas turbine increases, the compressor As the ratio increases, so does the temperature.

Therefore, when cooling the turbine blades, the temperature difference between the cooling air and the mainstream gas decreases accordingly, and the cooling effect deteriorates.

Furthermore, the temperature of the cooling air increases as it is exposed to the surrounding high-temperature atmosphere on the way to the turbine blades, and this tendency increases as the temperature of the combustion gas increases.

Therefore, when using the air compressed by the compressor as cooling air, the temperature of the turbine blades is
Under conditions where the temperature is kept below a certain level necessary to maintain its strength, it is impossible to raise the mainstream gas temperature above a certain value even if the amount of cooling air is increased.

As a countermeasure to this problem, there are systems in which the cooling air is once guided outside the gas turbine and cooled separately using an air-fin cooler, etc., but in this case, although the cooling air temperature decreases, the structure is In addition, the pressure drop increases due to the lengthening of the air flow path, and the difference between the cooling air pressure and the gas pressure at the turbine inlet becomes smaller, resulting in insufficient film cooling of the leading edge of the first stage stator blade. The problem is that it is possible.

Furthermore, if the temperature of the gas used in the gas turbine increases, the temperature of the combustor also increases, which poses a problem in the heat resistance of the members that make up the combustor. That is, increasing the temperature of the gas used in the gas turbine means increasing the combustion temperature, and each part of the combustor is exposed to higher temperature combustion gas.

Here, a large amount of dilution air flows into the inner cylinder of the combustor from the surroundings, and this dilution air blocks the heat of the combustion gas and protects the inner cylinder from exceeding an allowable temperature.

However, the combustor transition piece, for example, has several gaps.
It has a double structure consisting of an inner and outer panel with a diameter of about mm, and a small hole is made in the outer panel to introduce air compressed by a compressor to cool the inner panel. Air is blown into the passage from here, forming an air film to block the heat of the combustion gas, but the temperature of the air itself compressed by the compressor becomes high, and a sufficient cooling effect cannot be achieved. I can't. If the amount of air for cooling is increased as a countermeasure, the power required for the compressor will increase and the average mainstream gas temperature will also decrease, resulting in a problem that the cycle efficiency of the gas turbine will decrease.

[Purpose of the invention]

The present invention solves the above conventional problems and improves the efficiency of the gas turbine cycle by effectively cooling the cooling air of the gas turbine with water injected from an injection valve provided in the gas turbine. The purpose is to provide a gas turbine that can

[Summary of the invention]

The present invention provides a gas turbine in which a part of the air compressed by a gas turbine compressor is used as cooling air to cool the turbine blades, and the inside of the combustor chamber of the gas turbine is divided into two parts: a combustor main body side and a combustor transition piece side. At the same time, a water spray tube with a closed combustor main body side is provided through the partition, and a plurality of air inlets with a plurality of swirl vanes are provided in the outer tube of the water spray tube, and the center of each air inlet is provided. It is characterized by having an injection valve for injecting cooling water.

〔Example〕

Embodiments of the gas turbine of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the gas turbine 1 has a turbine 4
and a compressor 2 driven by the compressor 2.

In the combustor chamber 10, as shown in FIGS. 2A and 3, the combustor intermediate support plates 13 are in contact with the combustor intermediate support plates 13 on both sides to form partition walls,
The combustor inner cylinder 11 and the combustor flow guide 13 side provided to cover the outer periphery of the combustor inner cylinder 11 and the combustor inner cylinder 11
The combustor transition pipe 14 side connected to the terminal end of the combustor transition pipe 14 side is further partitioned into a
0 is formed. As shown in FIG. 2B, a water spray pipe 5 is provided in the combustor chamber 10, passing through the combustor intermediate support plate 13 and closed on the combustor main body 13 side and open on the combustor transition pipe 14 side. .

As shown in FIGS. 4 to 6, the outer cylinder 51 constituting the water spray cylinder 5 is provided with a plurality of air suction ports 52 each having a plurality of spiral blades 53. Injection valve 6 (injection nozzle) respectively
is provided. Further, an opening 5 is provided in a part of the outer cylinder 51.
4 is provided.

The injection valve 6 is connected to the gas turbine 1 as shown in FIG.
A pipe 7 is connected to an external water supply source 9 via a valve 8, and the valve 8 starts or stops water injection.

The combustor transition piece 14 has a double structure consisting of an inner plate 15 and an outer plate 16, as shown in FIG. It has a structure that maintains a gap.

Also, a space 27 sealed between the connecting member 21 and the torque tube 22 by a compressor high pressure side seal ring 23 and a turbine inlet side seal link 24.
The space 2 in the cooling air chamber 30 and the torque tube 22 is formed by the cooling air bleed holes 25 and 26.
It communicates with 8.

Next, to explain the operating state of the gas turbine, the air compressed by the compressor 2 enters the combustor chamber 10 as shown in FIG.
As shown in FIG. 2B, a part of the water is supplied to the outer cylinder 5 which is given a swirl by passing between the swirling vanes 53 of the air inlet 52 provided in the outer cylinder 51 of the water spray cylinder 5.
The cooling air flows into the inside of the cooling air 1, where it mixes with the spray water injected by the injection valve 6, and the cooling air is cooled by the evaporation of the water. Further, a part of the air flows into the outer cylinder 51 through the opening 54, agitates the airflow inside the outer cylinder 51, and promotes evaporation of the spray.

In FIG. 2B, the air cooled within the water spray tube 5 enters the cooling air chamber 30, and a portion is supplied to the turbine stationary blades 35, 37 through the cooling air hole 33 of the turbine blade ring 33. , a part enters the space 20 from the small hole 19 in the outer plate 16 of the combustor transition piece 14 as shown in FIG. The cooling air enters the space 27 from the cooling air bleed hole 25 of the torque tube 2.
2 from the cooling air bleed hole 26 to the torque tube 22
The spacer disk 41 enters the space 28 from the turbine disk 40 air hole 44 to the spacer disk 41 air hole 44.
further enters the space 45 between the turbine disks 40, 42, cooling air holes 46, 47 and 4.
8 to the turbine rotor blades 36, 38 to cool them.

〔Effect of the invention〕

In the gas turbine of the present invention, a combustion chamber is partitioned into a combustor main body side and a combustor transition pipe side, and a water spray cylinder is provided which penetrates this partition and is closed on the combustor main body side. A plurality of air intake ports each having a plurality of swirl vanes are provided, and an injection valve is provided at the center of each air intake port.

With the above configuration, the present invention can achieve the following effects.

(a) The combustor chamber is divided into the combustor main body side and the combustor tail cylinder side, and air is sucked into the water spray cylinder through the air intake port.

This air intake port is provided with a plurality of swirling vanes and an injection valve in the center thereof, so that the air is given a swirl by the swirling vanes and flows into the outer cylinder. Since water is injected into the air stream from an injection valve, the air stream and the spray are strongly agitated and evaporation is promoted.

In addition, when a spiral type injection valve is used as an injection valve, the spray is atomized and the water is sprayed in an umbrella shape at a wide angle, so this spray mixes well with the air flow, and the atomized water is It can be evaporated quickly and the cooling air can be cooled quickly.

Moreover, since the water spray tube is provided with a plurality of air intake ports, it is possible to reduce the amount of injection per injector, thereby reducing the particle size of the injected spray and making it easier to evaporate.

(b) When cooling each part of the turbine, it is necessary to avoid direct application of water droplets to high-temperature turbine elements. In particular, the temperature of the combustor transition piece is high as it comes into direct contact with the combustion gas, and it is made up of relatively thin plates, so even a small drop of water will cool this area rapidly, causing cracks due to thermal stress. However, in the present invention, water is sprayed into the stirred air stream as described above and supplied into the water spray cylinder, so by the time the water reaches the cooling air chamber, the water has completely evaporated and the temperature is high. Water droplets do not come into direct contact with worn-out turbine elements, and damage to the turbine elements can be prevented.

(c) The combustor chamber is divided into the combustor main body side and the combustor transition pipe side, an air inlet with swirling vanes is attached, and a water spray pipe is installed that closes the combustor main body side, so cooling is achieved by spraying. This air does not flow into the combustor main body, and the air supplied to the combustor is not cooled.

(d) The cooling air is effectively cooled because water is sprayed into the swirling airflow and evaporation of water is promoted in a mixed state.This cooled air cools the turbine blades, etc. The cooling effect of blades, etc. is greatly improved, and it is possible to increase the temperature of the gas used without increasing the amount of cooling air, resulting in improved turbine cycle efficiency.

Note that when increasing the amount of cooling air to improve the cooling capacity of turbine blades, etc., the amount of heat received by the turbine blades increases as the gas temperature increases, and the temperature of the cooling air itself also increases considerably. Even if the amount of cooling air is increased, it is difficult to significantly improve the cooling effect because the temperature difference between the cooling air and the turbine blades, etc. becomes small.However, the present invention can effectively reduce the temperature of the cooling air. By lowering it, the cooling effect of turbine blades, etc. can be increased.

(E) The combustor chamber is divided into the combustor main body side and the combustor transition piece side, a cooling air chamber is configured to surround the combustor transition piece, and the cooling air that has been effectively cooled as described above is used for cooling. Since the air is supplied to the air chamber, lowered temperature air can be used to cool the combustor transition piece. Therefore, since the temperature difference between this cooling air and the combustor transition piece is large and the cooling effect is high, it is possible to increase the temperature of the gas used in the gas turbine without increasing the amount of cooling air.

(f) Since water is simply sprayed into the airflow stirred in the cooling air passage inside the gas turbine, there is less pressure loss compared to conventional equipment that cools the gas turbine by first guiding the cooling air to the outside of the gas turbine. Cooling air can be cooled.

Therefore, there is an advantage that film cooling of the leading edge of the first stage stator blade of the turbine can be performed without any problem, which is impossible when cooling air is introduced to the outside of the gas turbine.

[Brief explanation of drawings]

FIG. 1 is a schematic system diagram of a gas turbine according to an embodiment of the present invention, with the upper half showing the AA cross section in FIG. 3, and the lower half showing the BB cross section in FIG. 3. 2A and 2B are side sectional views of the main parts of the gas turbine, FIG. 2A is the upper half of FIG. This is the lower half of the figure, that is, the cross section taken along line B-B in FIG. FIG. 4 is a sectional view of the air suction port, FIG. 5 is a plan view thereof, and FIG. 6 is a perspective view of a swirl vane provided at the air suction port. 1...Gas turbine, 2...Compressor, 4...Turbine, 5...Water spray cylinder, 6...Injection valve, 7...
Piping, 8...Valve, 9...Water supply source, 10...Combustor chamber, 11...Combustor inner cylinder, 13...Combustor intermediate support plate, 14...Combustor transition piece, 51... outer cylinder,
52... Air intake port, 53... Swivel vane, 54...
...opening.

Claims (1)

[Claims] 1. In a gas turbine in which a part of the air compressed by a gas turbine compressor is used as cooling air to cool the turbine blades, the combustion chamber of the gas turbine is partitioned into a combustor main body side and a combustor chamber transition pipe side, and
A water spray cylinder with the combustor main body side closed is provided through the partition, and a plurality of air inlets with a plurality of swirl vanes are provided in the outer cylinder of this water spray cylinder, and an injection valve is placed in the center of each air inlet. A gas turbine characterized by being provided with.