JPH0137576B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to gas turbines. More specifically, the present invention relates to a gas turbine that prevents water from dripping from a water spray device.

In recent years, in order to improve the performance and output of gas turbines, the gas temperature used in gas turbines has tended to become higher and higher.

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.

Therefore, to cool the turbine blades, a part of the air compressed by the compressor is guided into the blades as cooling air to perform film cooling, impingement cooling, convection cooling, etc., but the amount of cooling air used is In order to keep the blade below a certain temperature, it is necessary to increase as the gas temperature increases.

However, an increase in the amount of cooling air used leads to a decrease in gas turbine cycle efficiency due to an increase in the power required for compressing the cooling air and a decrease in the average gas temperature due to the increase in the amount of cooling air mixed with the mainstream gas. be.

In addition, since the cooling air uses air compressed by the compressor driven by the turbine, its temperature is lower than that of combustion gas, but as the output of gas turbines 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 becomes correspondingly smaller, and the cooling effect becomes worse.

In addition, the cooling air is exposed to the surrounding high-temperature atmosphere on the way to the turbine blades, so its temperature increases, and this tendency increases as the combustion gas temperature increases.

Therefore, when using the air compressed by the compressor as cooling air, the temperature of the turbine blades is
Under the conditions of keeping the temperature below a certain level required 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 is a method in which the cooling air is guided outside the gas turbine and cooled using an air-fin cooler, etc., but in this case, although the cooling air temperature decreases, the structure becomes complicated and the pressure drop increases. There is a problem in that the difference between the pressure of the cooling air and the gas pressure at the turbine inlet becomes small, making it impossible to film-cool the first-stage stationary blades.

On the other hand, it is known to detect the temperature inside the bearing housing and adjust the proportion of cooling water.
If cooling water drips onto hot turbine components at the start or end of water spraying, this portion will be rapidly cooled, causing cracks.

Here, if water is sprayed when the air in the cooling air chamber is not at a sufficient temperature to quickly evaporate the entire amount of water sprayed by the water spray device, such as when the gas turbine is started or stopped, this water will be evaporated quickly. The water droplets directly hit the turbine components in the cooling air chamber, rapidly cooling those parts and causing cracks, so the entire amount of water sprayed by the air in the cooling air chamber quickly evaporates. Water should not be sprayed unless the temperature is sufficient to cause

In addition, when stopping water spraying, if you simply close the main valve of the piping system that supplies water, the pressure of the water remaining between that valve and the water spraying time will decrease, preventing it from becoming atomized. Water from the spray device must be prevented from dripping, as this can cause the above-mentioned problems.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to prevent water from dripping when a water spray device starts spraying or when spraying ends, thereby preventing damage to turbine components.

That is, the present invention forms a cooling air chamber on the combustor transition pipe side by partitioning the combustor chamber of a gas turbine with a combustor support plate, and also provides a temperature sensor and a water spray device in the cooling air chamber. The water spray device has a first valve in the middle of a pipe communicating with the high pressure air source, a second valve in the middle of the pipe communicating with the water supply source, and the water spray device has a first valve in the middle of a pipe communicating with the water supply source, and The regulator attached to the cooling air chamber opens the first and second valves in this order when the temperature inside the cooling air chamber exceeds the set value, and opens the second and second valves when the temperature inside the cooling air chamber falls below the set value. This is characterized in that the valves are closed in the order of the first valve.

Embodiments of the gas turbine of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram of the gas turbine in the embodiment of the present invention. This gas turbine 1 is constructed by the following.

Next, FIG. 2 is an enlarged side sectional view of the main part of the gas turbine 1 shown in FIG. 1, and cooling air within the gas turbine 1 flows as indicated by arrow A in the figure.

Further, the combustor chamber 11 is partitioned by a combustor intermediate support plate 13, so that the cooling air chamber 1
2 are configured.

As shown in the main part front view of FIG. 3, the combustor intermediate support plate 13 partitions the combustor chamber 11 so that both sides thereof are in contact with the adjacent combustor intermediate support plate 13. An opening 14 is provided in a part of the outer periphery, etc., through which the cooling air A passes.

The cooling air chamber 12 is also provided with a detector 6 for detecting temperature and a spray device 5 capable of spraying water. A valve 7 is provided in the middle of the connection, and this valve 7 is controlled by a regulator 10.

Further, primary air is supplied to the above-mentioned spray device 5 from an external high-pressure air source 34 through an air pipe 33.
A valve 32 is also provided in the middle, and this valve 32 is also controlled by the regulator 10. When the detector 6 detects a temperature higher than the set temperature, the regulator 10 first opens the valve 32 based on the signal to inject air as a primary, and then opens the valve 7 to spray water. When the temperature detected by the detector 6 falls below the set temperature, the valve 7 is closed and the spraying is stopped.
Close 2.

Here, the set temperature is a temperature at which sprayed water quickly evaporates.

In addition, the connecting member 19 and the torque tubes 20, 2
1, a space 24 sealed by a compressor high pressure side seal ring 22 and a turbine inlet side seal ring 23, a connecting member 19, and a torque tube 21.
Cooling air bleed holes 25 and 26 provided in the turbine rotor blades 16 and 18 constitute cooling air passages to the turbine rotor blades 16 and 18, respectively.

The air compressed by the compressor 2 described above enters the combustor chamber 11, and most of it is supplied to the combustor 3, but some of it is supplied to the opening 14 of the combustor intermediate support plate 13 shown in FIG. and enters the cooling air chamber 12.

Then, the air temperature in the cooling air chamber 12 is detected by the detector 6, and if it is higher than the set temperature, the valves 32 and 7 are sequentially opened, and water is sprayed from the spray device 5 using air as the primary, and the cooling air is A
is cooled. Further, when the temperature in the cooling air chamber becomes lower than the set temperature, the valves 7 and 32 are closed in this order.

A part of the cooling air A cooled in the cooling air chamber 12 is supplied to the turbine stationary blades 15 and 17 through the cooling air holes 28 and 28 of the turbine blade ring 27, and the rest is supplied to the cooling air bleed hole 25 and the space. 24, passes through the cooling air bleed hole 26, enters the hollow part in the torque tubes 20, 21, and further enters between the turbine disks 30, 30 from the ventilation hole 29, and enters the cooling air hole 31, 3.
1 to turbine rotor blades 16 and 18.

As described above, the present invention forms a cooling air chamber on the combustor transition pipe side by partitioning the combustor chamber of a gas turbine with a combustor support plate, and also installs a temperature sensor and water spray in the cooling air chamber. a first valve in the middle of a pipe communicating with the high pressure air source; a second valve in the middle of the pipe communicating with the water supply source; The regulator attached to temperature detection opens the first and second valves in this order when the temperature inside the cooling air chamber exceeds the set value, and opens the second valve when the temperature inside the cooling air chamber falls below the set value. Since the valves are closed in the order of the first valve, it is possible to prevent water from dripping after starting or stopping water spraying, thereby making it possible to prevent damage to turbine components.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a gas turbine according to an embodiment of the present invention, FIG. 2 is an enlarged side sectional view of the main part of the gas turbine in FIG. FIG. 3 is a front view of main parts of the support plate. 1...Gas turbine, 2...Compressor, 3...Combustor, 4...Turbine, 5...Spray device, 7...
Valve, 9... Water supply source, 10... Regulator, 12...
Cooling air chamber, 13... Combustor intermediate support plate, 15,
17... Turbine stator blade, 16, 18... Turbine rotor blade, 32... Valve, 34... High pressure air supply source, A
...cooling air.

Claims (1)

[Claims] 1. A cooling air chamber is formed on the combustor transition pipe side by partitioning the combustor chamber of the gas turbine with a combustor support plate, and a temperature sensor and a water spray device are disposed in the cooling air chamber. The water spray device has a first valve in the middle of a pipe communicating with the high-pressure air source, a second valve in the middle of the pipe communicating with the water supply source, and a regulator attached to the temperature sensor. The device opens the first and second valves in this order when the temperature in the cooling air chamber exceeds the set value, and opens the second and first valves in that order when the temperature in the cooling air chamber falls below the set value. A gas turbine characterized by a closing valve.