JP2675391B2 - gas turbine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a gas turbine capable of effectively removing dust from cooling air.

[Prior Art] The combustion temperature of a gas turbine tends to increase year by year to improve thermal efficiency. Therefore, the air cooling structure of the moving blades of the gas turbine, especially the first-stage moving blades, is becoming complicated.

That is, the air cooling structure operates from convection cooling in which the air extracted from the compressor is passed straight through the first-stage rotor blades, and recently, in response to an increase in combustion temperature, it is operated by a return flow system that bends and returns in the rotor blades. Wing cooling is becoming more common.

In this type of cooling blade, a complicated cooling air passage which is bent inside is formed, and a projection called a turbulence promoter is arranged on the inner wall of the cooling air passage to desire heat transfer.

The air that enters the compressor of the gas turbine is filtered by an inlet filter and large dust is removed. However, the gas turbine for power generation is often operated continuously for one year, and if the extracted air is used as it is. , Minute dust and rust etc. in the channel gradually accumulate in the channel of the first stage rotor blade,
Reduces the cooling efficiency of the first stage rotor blades.

The accumulation of dust does not cause much problems if the cooling air passage is not bent, but if it is complicatedly bent like the return flow type, very small dust will cool the first stage rotor blades, etc. It is deposited on the turbulence promoter on the inner wall of the wing.

If the deposition exceeds the limit, the cooling efficiency will decrease significantly, the rotor blade will burn out, the dust will be unevenly deposited, and the heat transfer imbalance caused by the deposit will result in uneven rotor blade elongation. Frequent maintenance and cleaning is necessary as it can have the serious consequence of causing vibrations in the.

In addition, the efficiency of the compressor also declines over time due to the accumulation of dust on the blades.In order to restore the efficiency of the compressor to the initial state, rice was introduced into the compressor inlet and accumulated on the blades of the compressor. Dust is being removed, and if the cooling air in the rotor blade is not filtered, rice grains will become fine powder of 0.1 mm or less due to the compressor and will be deposited inside the rotor blade.

Regardless of whether the blade cooling method is the return flow method or not, minute dust particles adversely affect the cooling efficiency of the blade and limit the continuous operation time, so to clean the cooling air. Various ideas have been made.

Examples of such a conventional technique include, for example, Shokai 60-17.
There is one disclosed in Japanese Patent No. 1935.

That is, the publication discloses a device in which the extracted cooling air is once guided to the outside and filtered.

[Problems to be Solved by the Invention] However, in the prior art disclosed in the above publication, the cooling air is once guided to the outside to be filtered, so that it takes up space and is structurally complicated. However, there is a problem that not only the size increases but also the cost increases.

The object of the present invention is to simplify the structure without increasing the size,
An object of the present invention is to provide a gas turbine that can reliably clean the air that cools the moving blades before being sent to the moving blades and that has excellent maintainability.

[Means for Solving the Problems] The above object is to provide an air passage for introducing cooling air into the center of rotation of a rotating body that supports the moving blade and guiding the cooling air to the moving blade. It is achieved by a gas turbine provided with. It is rational to use the cooling air extracted from the compressor, but it may be introduced from the outside.

In the case where the bleed air from the compressor is used as the cooling air, the above-mentioned object is to open an air passage so as to communicate the center from the dummy rotor equipped with the introduction fan for bleeding the cooling air from the compressor to the rotating body supporting the moving blades. This is accomplished by installing a dust remover in this air passage.

In addition, an opening is provided at the end of the air passage so that the dust remover can be inserted and removed, and a verification unit that measures the air pressure of the downstream flow of the dust removal means is provided. The object is achieved by means of communication between the transmitting unit provided and the receiving unit provided at a position separated from the rotating body.

Generally, when it is necessary to clean the air in the vicinity of a rotating body that rotates at high speed, an air passage is drilled in the center of the rotating body that rotates at high speed, and dust is removed so as to intervene in this air passage. The purpose is achieved by providing a container.

[Operation] During operation of the gas turbine, the cooling air is guided into the moving blade through the air passage in the center of the rotating body, which is the rotation center of the moving blade, and the moving blade is cooled. The cooling air passes through the dust remover and is cleaned before entering the rotor blades.

In the case where cooling air is extracted from the compressor by an introduction fan, the extracted cooling air is air that is drilled from a dummy rotor that rotates at the same number of revolutions as the rotor blade to a rotor that supports the rotor blade. It is guided to the moving blade through the passage. And
Before entering the blade, it is cleaned by a dust remover provided in the air passage.

Since the air taken into the compressor is filtered by the inlet filter, fine dust is finally removed by this dust remover, and even in a return flow type cooling type gas turbine, dust and the like will remain on the inner wall of the rotor blades for a long period of time. Since the turbulence promoter is not deposited on the part, the maintenance frequency can be reduced and the gas turbine can be operated efficiently.

The dust remover is inserted and removed from an opening provided at the end of the air passage at the time of mounting and maintenance. Further, in the dust remover, the air pressure of the subsequent flow is measured by the verification section, and the result is sent from the transmission section to the receiver at the non-rotating part. The change in the air pressure in the wake of the dust remover can be constantly monitored and used as data for maintenance and inspection.

Generally, even in a machine having a rotating body that rotates at a high speed, an air passage can be bored in the center of the rotating body and the air can be passed through a dust remover in the air passage for cleaning.

Embodiments Various embodiments of the present invention will be described below with reference to the drawings.

 1 to 4 show a first embodiment of the present invention.

As shown in FIG. 1, the gas turbine 10 includes a compressor 20,
The combustor 30 and the turbine section 40 are major components.
The compressor 20 and the turbine section 40 rotate at high speed about a common rotation center axis AA.

The compressor 20 is formed by solidifying a dummy rotor 25 on the high-pressure side end of a compressor rotor 21, and a compressor blade chamber 22 is formed on the outer circumference. An introduction fan 26 is interposed between the compressor rotor 21 and the dummy rotor 25, and the outer periphery of the insertion fan 26 is a compressor blade chamber.
It faces the bleeder 23 that opens to 22. The introduction fan 26 is also called a so-called bore fan.

An air passage 28 through which the cooling air A1 extracted by the introduction fan 26 passes is formed in the cylinder 27 of the dummy rotor 25. The dummy rotor 25 is used as one of the rotating shafts when the compressor rotor 21 is individually balanced.

The combustor 30 is a part that receives compressed air from the compressor 20 and burns fuel, and sends the combustion gas G exceeding 1000 ° C. to the turbine part 40.

The turbine section 40 has a turbine rotor 41 in which bases of moving blades 42a to 42c are planted, and cooling air delivery paths 43a to 43c are provided at important points of the turbine rotor 41, and at least the moving blades 42a and 42b have a return flow. It is of a cooling type and has a curved cooling path inside, and the delivery paths 43a and 43b are blades 42a and 4b.
It is connected to the cooling passage inside 2b.

A turbine blade chamber 44 is formed on the outer periphery of the turbine rotor 41. Inside the turbine blade chamber 44, moving blades 42a to 42c and stationary blades 44a to 44c fixed to a housing that is a non-rotating side are provided as combustion gas. They are arranged alternately in the direction of G flow.

The center of the turbine rotor 41 is hollow and the air passage
45 is formed, and the start ends of the delivery paths 43a to 43c are connected to the air passage 45. Further, the air passage 45 is connected to the air passage 28 of the dummy rotor 25 via the connecting cylinder 46.

A bearing member 47 is fixedly provided at the rear end of the turbine rotor 41,
A through hole 47a is formed in the bearing member 47 and the through hole 4a is formed.
A plug 48 for closing the opening of 7a is provided.

As a dust remover, the filter cassette 50 is installed so that the axial center of the dummy rotor 25 and the axial center of the filter cassette 50 are aligned with each other so as to intervene in the air passage 28 of the dummy rotor 25. Since the filter cassette 50 also rotates together with the turbine rotor 41, the balance is naturally corrected.

2 and 3 show a detailed cross section of the filter cassette 50.

The filter cassette 50 holds a filter main body 53 between an end plate 51 on the air inflow side and an end plate 52 on the outflow side, and includes a porous inner cylinder 53a and a porous outer cylinder 53b for reinforcing the filter main body 53. 53 is mounted on the inner diameter side and the outer diameter side.

The outer circumferences of the end plates 51, 52 are circular and are fitted to the cylindrical shape of the air passage 28 of the dummy rotor 25 with a certain fit. A receiving port 51b is opened in the end plate 51 on the inflow side, and the notch 51a on the outer periphery captures the pin 28a implanted in the air passage 28 of the dummy rotor 25 and serves as a detent for the filter cassette 50.

The end plate 52 on the outflow side is provided with notches 54a to 54c as air passage passages at a plurality of locations along the entire circumference. Also, the end plate on the outflow side
Corresponding to 52, an entire circumferential groove 28b is engraved on the inner circumference of the air passage 28 of the dummy rotor 25, and the filter cassette 50 is fitted to the entire circumferential groove 28b to be separated from the air passage 28 of the dummy rotor 25 to the outside. A snap ring 55 is attached to prevent this.

The snap ring 55 is ring-shaped and has tongue pieces 55a and 55b formed inward at two positions of the terminal. The tongue pieces 55a and 55b are pinched to deform the snap ring 55 inwardly, and the groove of the dummy rotor 25 is deformed. The filter cassette 50 can be attached and detached by taking it in and out of the 28b. Further, a screw hole 56 is formed in the end plate 52 on the outflow side of the filter cassette 50.

A protrusion 28c that abuts the inflow side end plate 51 of the filter cassette 50 is provided on the inner periphery of the air passage 28 of the dummy rotor 25, and the air passage 28 and the air passage 45 of the turbine rotor 41 are provided.
The general diameter of is a diameter that allows the filter cassette 50 to be loosely inserted, and the same applies to the through hole 47a of the bearing member 47 fixed to the rear end of the turbine rotor 41.

Figures 4 and 5 show how to attach and detach the snap ring.
Is shown.

The hire 60 has a through hole 47a in the bearing member 47 without the plug 48.
And a guide cylinder 62 for the air passage 28 of the dummy rotor 25 is formed at the end of the hollow support cylinder 61 with a length sufficient to reach the filter cassette 50 through the air passages 45, 28.
A pin joint 63 is provided at the tip, and two wide fingers 64a, which are pivotally supported by the pin joint 63, are shaped like scissors.
64b extends to the tip.

From the link part 65 for opening and closing the fingers 64a, 64b to the rod 66
Extends inside the guide cylinder 62 to the base end, and the joint 67a
Is provided at the end of the rod 66, from which a screw shaft 68 screwed to the base end of the support cylinder 61 extends, and an operation handle 69 is fixedly provided at the end thereof.

The two fingers 64a, 64b are opened and closed by the movement of the rod 66 in the support cylinder 61, and the two tongues 55a, 55 of the snap ring 55 are opened and closed.
It is designed to fit exactly into b.

FIG. 6 shows the structure of the employment 70 for attaching and detaching the filter cassette.

Similar to the snap ring attachment / detachment 60, the filter cassette attachment / detachment 70 is long enough to reach the filter cassette 50 through the through hole 47a of the bearing member 47 and the air passages 45 and 28, and the filter cassette 50 screw. The hole 56 is used to fix the filter cassette 50 to the tip of the hire 70 and replace it.

The hire 70 has a screw 72 at the tip so as to be screwed into the screw hole 56 of the filter cassette 50, and an operation handle 73 at the base end.
And a working rod 71 having a flange 74, and a working rod
The outer case 75 has a guide cylinder 76 at its tip and a flange 77 at its base.

The operation of the gas turbine and the air purifying device having the above configurations will be described below.

When the gas turbine 10 is operated and the compressor rotor 21 and the turbine rotor 41 are rotated, a part of the air compressed by the compressor 20 is extracted as the air A1 for cooling the moving blades by the introduction fan 26, and the dummy rotor 25 is cooled. It is sent to the air passage 28 as air supply A2 and is filtered as it passes through the filter cassette 50.

That is, the air supply A2 is the inlet of the filter cassette 50.
51b enters the filter cassette 50, and a porous inner cylinder 53
a, the filter body 53, the porous outer cylinder 53b in this order
It emerges in the space between the peripheral wall of 28 and the filter body 53. Since the filter body 53 does not allow even minute dust to pass through, the air discharged into this space is extremely clean.

The air supply A2 is sent as air supply A3 from the rear end of the air passage 28 of the dummy rotor 25 through the connecting cylinder 46 in the axial direction of the rotating shaft,
It enters the air passage 45 of the turbine rotor 41 of the turbine section 40.

The air supply A3 flows from the air passage 45 as the cooling air A4, A5 in the delivery paths 43a, 43b, enters the moving blades 42a, 42b, and cools.

The inspection or replacement of the filter cassette 50 is performed by the employment 60 for attaching and detaching the snap ring and the employment 70 for attaching and detaching the filter cassette.

The plug 48 at the end of the through hole 47a of the bearing member 47 is removed, and the air passage 28 and the air passage 45 are electrically connected to the outside. Insert the employment 60 from the opened opening, and insert the filter cassette 5 through the through hole 47a, the air passage 45, the connecting cylinder 46, and the air passage 28.
Reach 0. Since the guide cylinder 62 is just fitted into the air passage 28, the centers thereof are generally aligned.

When it arrives, 2 of the snap ring 55 with two fingers 64a, 64b
Grasp the tongue pieces 55a, 55b and rotate the handle 69.
When the operation handle 69 rotates, the screw shaft 68 screwed to the base end of the support cylinder 61 is displaced in the vertical direction, whereby the rod 66 is pulled in the vertical direction.

Then, the link portion 65 causes the fingers 64a and 64b to swing around the pin joint 63, the tongues 55a and 55b are squeezed, the diameter of the snap ring 55 becomes smaller, and the tongue pieces 55a and 55b come off the outflow side end plate 52,
It can be extracted from the air passage 28 of the dummy rotor 25. In order to confirm the positions of the tongues 55a and 55b, it is easy to fix the endoscope using an optical fiber to the support tube and observe the inside.

The snap ring 55 is taken out, the snap ring attachment / detachment 60 is removed, and the filter cassette 50 is pulled out by the filter cassette attachment / detachment 70.

As in the case of the snap ring attachment / detachment 60, the tip of the filter cassette attachment / detachment 70 reaches the filter cassette 50, and the screw 72 at the tip of the operation rod 71 is screwed on the end plate 52 of the filter cassette 50. In addition, the operation handle 73
Rotate and screw in.

After screwing in considerably, apply a load by applying a hydraulic jack (not shown) to the space between the flanges 74 and 77,
The operating rod 71 of the hire 70 and the filter cassette 50 are integrally pulled out toward the front, and when loosened, the entire hire 70 for attaching / detaching the filter cassette can be pulled out to easily pull out the filter cassette 50.

If the procedure is the reverse of the above, the filter cassette 50 can be easily inserted and installed in the air passage 28.

The air compressed by the compressor 20 passes through the filter of the inlet house of the gas turbine 10 to be clean air, but if it is used for many years, the capacity of the filter also decreases,
In addition, rust on the wall surface of the air passage of the gas turbine main body may fall off due to the air flow or vibration, and when it reaches the extraction unit 23 of the compressor 20, it may not always be clean.

Even in such a case, since the cooling air is filtered by the filter body 53 of the filter cassette 50 before reaching the cooling blades 42a, 42b of the turbine, clean air cools the cooling blades 42a, 42b. Therefore, dust is not accumulated on the turbulence promoter of the moving blades 42a and 42b, and the cooling efficiency is not reduced.

 7 and 8 show a second embodiment.

When dust is accumulated on the filter body 53 of the filter cassette 50 and becomes clogged, the pressure loss between the air inlet side and the outlet portion of the filter body 53 increases. The filter cassette 50 can be monitored by detecting this pressure loss. One of the means is shown below.

Since the overall configuration has many points in common with the first embodiment, similar parts will be described with the same reference numerals. The same applies to other embodiments described later.

The monitoring device 80 according to this embodiment includes a filter cassette 50.
The pressure on the inlet side and the pressure on the air passage are detected by a detector 81 provided near the plug 48 at the end of the air passage and transmitted to the non-rotating portion by the telemetry unit 85.

 The detection unit 81 is configured as follows.

A threaded hole 56 in the end plate 52 on the outflow side of the filter cassette 50 penetrates the inner diameter side of the filter body 53, and a long tube 82 screwed into the threaded hole 56 extends to the end of a through hole 47a following the air passage 45. .

The inside of the tube 82 forms a communication passage 82a for transmitting the air pressure on the inlet side of the filter cassette 50, and at the end of the communication passage 82a, a thin plate bellows portion 83 that is deformed due to the pressure difference between the both sides thereof.
Is provided.

The peripheral wall of the tube 82 is in contact with the through hole 47a continuing to the air passage 45, and an opening 82b for communicating the pressure thereof after the thin plate bellows portion 83 is formed in this peripheral wall.

A strain gauge (not shown) is attached to the thin plate bellows portion 83, and the deformation due to the pressure difference between the front and rear of the thin plate bellows portion 83 increases with an increase in pressure loss, which is detected by the strain gauge, and the output thereof is obtained by the telemetry unit 85. It is connected to the.

The telemetry unit 85 is an external power supply system, and is provided with a power antenna 86 that receives power from the power supply antenna 86a attached to the non-rotating unit. Further, a regulator 87 for converting the electric power received by the power antenna 86 into a direct current, a transmitter 88 that works with a direct current from the regulator 87, and a signal antenna 89 for transmitting a distorted signal output from the transmitter 88 to a receiving antenna 89a are provided. There is.

The output of the strain gauge of the thin plate bellows unit 83 is connected to the transmitter 88 of the telemetry unit 85, and the receiving antenna 89a that receives the output of the transmitter 88 on the non-rotating side in a contactless manner is connected to a receiving unit (not shown).

 The monitoring device 80 of this embodiment operates as follows.

When dust is accumulated on the filter body 53 of the filter cassette 50 and becomes clogged, the pressure loss between the air inlet side and the outlet side of the filter body 53 increases, and this pressure loss appears as a pressure difference.

The pressure on the inlet side of the filter cassette 50 is applied to the front side of the thin plate bellows portion 83 from the communication passage 82a, and the pressure of the air passage 45 and the through hole 47a is applied to the thin plate bellows portion 83 from the opening 82b, and the pressure difference causes the thin plate bellows portion 83a. When 83 is deformed, the output of the strain gauge (not shown) is the telemetry section 85 as an electric signal.
Is transmitted to

The telemetry unit 85 operates by converting the electric power received by the power antenna 86 into a direct current by the regulator 87, and the transmitter 88 receiving the signal from the detecting unit 81 transmits the pressure loss information from the signal antenna 89 and the receiving antenna. 89a receives it and sends it to the receiving part not shown.

The information received by the receiving unit may be regularly checked, and may be constantly monitored and used to warn the replacement of the filter cassette 50 when the pressure loss exceeds the limit value.

 FIG. 9 shows a third embodiment.

In this embodiment, a part of the air passage 28 of the shaft cylinder 27 of the dummy rotor 25 is widened to provide a diameter expansion chamber 57, which is a dust remover.

Since the dummy rotor 25 is rotating at high speed, dust, rust, etc. contained in the air that has flowed into the diameter expansion chamber 57 is pressed against the peripheral wall of the diameter expansion chamber 57 by centrifugal force and removed from the cooling air.

 FIG. 10 shows the fourth embodiment.

In the present embodiment, a diameter-expanding chamber 57 in which a part of the air passage 28 of the shaft cylinder 27 of the dummy rotor 25 is widened is provided, and a magnet 58 is attached to the peripheral wall to form a dust remover.

Dust, rust and the like contained in the air flowing into the diameter expanding chamber 57 are pressed against the peripheral wall of the diameter expanding chamber 57 by the centrifugal force and adsorbed by the magnet 58, and are effectively removed from the cooling air as compared with the third embodiment. .

[Advantages of the Invention] According to the present invention, it is possible to effectively remove dust in the air that cools the cooling blade of the gas turbine. It is possible to minimize the change over time of the cooling blades without depositing, reduce the maintenance work, and reduce the operating cost. It does not take up much space.

Since dust or the like is less likely to be accumulated, an imbalance of the rotating body does not occur due to a change in weight of the cooling blade, and smooth operation can be ensured.

In order to restore the efficiency of the compressor, even if rice is thrown into the compressor, fine rice powder can be captured before it reaches the cooling air flow path of the cooling blade, which can be used for gas turbine operation. There will be no trouble.

Since the dust remover is arranged at the center of the rotating body, it is not affected by centrifugal force, does not adversely affect the center balance, and requires a minimum space.

[Brief description of the drawings]

1 to 6 show a first embodiment of the present invention. FIG. 1 is a vertical cross-sectional view of a gas turbine, FIG. 2 is a vertical cross-sectional view showing a mounted state of a filter cassette, and FIG. Figure 2 III
FIG. 4 is a vertical cross-sectional view of the snap ring attachment / detachment attachment, FIG. 5 is a view of FIG. 4V arrow, and FIG. 6 is a vertical cross-section view of the attachment / detachment attachment / detachment of the filter cassette. Figure 8 is second
Fig. 7 shows an embodiment, Fig. 7 is a vertical cross-sectional view of a gas turbine, Fig. 8 is a vertical cross-sectional view of the vicinity of a detection unit and a telemetry unit of a monitoring device, and Fig. 9 is a vertical cross-sectional view of a gas turbine according to a third embodiment. A plan view and FIG. 10 are longitudinal sectional views of a gas turbine according to a fourth embodiment. 10 ... Gas turbine, 20 ... Compressor, 21 ... Compressor rotor, 22 ... Compressor blade chamber, 23 ... Bleed part, 25 ... Dummy rotor, 26 ... Introducing fan, 27 ... Shaft cylinder, 28 ... Air passage 30 ... Combustor, 40 ... Turbine part, 41 ... Turbine rotor, 42a-42c ... Moving blade 43a-43c ... Delivery path, 44a-44c ... Stationary blade, 45 ... Air Passage 50 ... Filter cassette, 51 ... Inflow end plate, 52 ...
… Outflow side end plate, 53 …… Filter body 60 …… Snap ring attachment / detachment, 70 …… Filter cassette attachment / detachment 80 …… Monitoring device, 81 …… Detecting unit, 85 …… Telemetry unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Arai 3-1-1 Sachimachi, Hitachi City, Ibaraki Hitachi Ltd. Hitachi factory (56) Bibliographic references Shokai 54-97605 (JP, U) Actual Open Sho 62-150545 (JP, U) Actual Open Sho 60-171935 (JP, U)

Claims (4)

(57) [Claims] 1. A rotating body which is a center of rotation of a moving blade, an air passage which is bored in the center of the rotating body, and which introduces cooling air into the moving blade, and is provided so as to be interposed in the air passage. And a dust remover for cleaning the cooling air guided to the moving blades. 2. A dummy rotor having an introduction fan for extracting cooling air from a compressor, the dummy rotor rotating at the same number of revolutions as the moving blade, and a rotating body supporting the moving blade and connected to a core shaft of the dummy rotor. An air passage that is provided so as to communicate with the core shaft of the dummy rotor and the center of the rotating body and guides the cooling air introduced by the introduction fan to the moving blades; A gas turbine comprising a dust remover for cleaning. 3. A gas turbine according to claim 1, wherein an opening is provided at an end of the air passage so that the dust remover can be inserted and removed. 4. A verification unit for measuring the air pressure in the downstream flow of the dust remover, and a transmission unit for sending the verification information by the verification unit are mounted on the rotating body, and at a portion separated from the rotating body. The gas turbine according to claim 1, further comprising a receiving unit that receives a signal from the transmitting unit.