JP2000186502A - Gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine which can control a wheel metal temperature at a fitting part between a wheel and a moving blade within a permissible value without using a special device and sufficiently suppress thermal stress which is generated by temperature difference in a radial direction of the moving blade. SOLUTION: This gas turbine is provided with a moving blade 1 which has a coolant flowing passage in interior thereof, a rotating wheel 5 which holds the moving blade by uneven engagement and has a coolant feeding passage which feeds a coolant to the moving blade via the uneven engagement part, and a seal member 53 which is provided at a gap of the uneven engagement part and prevents a leak of the fed coolant. The turbine is formed so as to be cooled by the coolant fed from the rotating wheel 5, and is provided with a covering plate 57 at one end side in the axial direction of the uneven engagement part between the wheel 5 and the moving blade 1 and a leakage coolant flowing passage 1a which penetrates in the axial direction at a connection projecting part between the moving blade 1 and the wheel 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a gas turbine, and more particularly to a gas turbine having a moving blade having a refrigerant flow passage therein and a rotating wheel having a refrigerant supply passage for supplying a refrigerant to the moving blade. The present invention relates to a gas turbine in which blades are formed to be cooled by a coolant supplied from the rotating wheel.

[0002]

2. Description of the Related Art In a gas turbine of this type, which has been generally employed, a plurality of moving blades having a refrigerant flow passage therein are held on the outer periphery of a wheel, and each moving blade is supplied from a rotating wheel side. It is usually formed to be cooled by a cooling medium. In this case, it is difficult to form a coolant flow passage for cooling in the concave / convex fitting portion between the rotor blade and the wheel, that is, the joining portion, and the temperature tends to be high.

With respect to cooling of a fitting portion between a moving blade and a wheel, for example, a cooling structure of a blade coupling portion as disclosed in Japanese Patent Application Laid-Open No. 6-307202 is known. In this case, the rotor blade is made of a ceramic material, and the wheel is made of a metal material. Since the ceramic blade is used without cooling, its temperature is high, and the metal temperature on the wheel side at the fitting portion may exceed the allowable value. Therefore, cooling air dedicated to cooling the fitting portion is supplied to the fitting portion between the wheel and the ceramic moving blade fitted into the groove on the outer periphery of the wheel to lower the temperature of the fitting portion. In this configuration, since air dedicated to cooling is introduced into the fitting portion, it is possible to supply air at a temperature, pressure, and flow rate suitable for cooling.

[0004]

As the efficiency and output of gas turbines have been increasing recently, the combustion temperature of gas turbines has been increasing. On the other hand, a single crystal heat-resistant material has been used as a metal material for the rotor blade, and the allowable temperature has been increased to 900 ° C. or more. However, since the wheels are required to use low-cost materials, the permissible temperature is about 450 ° C. to 550 ° C.

In general, a radial gap is provided in a fitting portion between a wheel and a moving blade in consideration of machining accuracy and assemblability, and the gap is formed between an upstream wheel side surface and a downstream wheel side surface. It communicates in the axial direction. In addition, intrusion-preventing air is introduced into the outer periphery of the wheel on the upstream and downstream sides of the mainstream gas to reduce the inflow of high-temperature mainstream gas. Air flows from the upstream side to the downstream side in the gap between the fitting portions.

In order to increase the efficiency of the gas turbine, it is necessary to raise the temperature of the mainstream gas and to reduce the amount of air for preventing intrusion. As a result, the temperature of the wheel metal of the fitting portion rises. Since the fitting portion on the wheel side bears the centrifugal force of the rotor blade, high stress is generated. When the temperature of the wheel metal increases, the allowable stress of the fitting portion on the wheel side also decreases, so that the reliability decreases.

[0007] As the temperature of the gas turbine increases, the high-temperature air on the side surface of the upstream wheel not only passes through the clearance of the fitting (engagement) portion, but also increases the wheel temperature due to heat intrusion from the contact portion between the moving blade and the wheel. May rise. As described in the related art, it is conceivable to supply a coolant exclusively for cooling the fitting portion gap. However, since the blade cooling coolant is supplied to the moving blades through the wheel, the fitting portion gap is supplied. When a dedicated refrigerant is supplied, two types of refrigerant supply systems are required, which complicates the structure of the wheel and the fitting portion and lowers the reliability.

From this, it is considered effective to branch a part of the refrigerant before cooling the rotor blades to cool the gap at the fitting portion. However, the pressure of the refrigerant before cooling the moving blades is set to a sufficiently high pressure in consideration of the pressure loss due to the cooling of the blades, and the temperature of the refrigerant supplied to the blades is from 250 ° C.
The temperature is about 300 ° C., which is sufficiently lower than the allowable temperature of the wheel. When this high-pressure and low-temperature refrigerant is introduced into the gap between the fitting portions, the pressure difference between the refrigerant and the downstream wheel side, which is the outlet position of the refrigerant, is large. There is a risk that it will.

If the temperature of the fitting portion is lowered by supercooling the moving blade side fitting portion, there is a problem that thermal stress increases due to a temperature difference between the moving blade fitting portion and a portion where the moving blade comes into contact with the mainstream gas. In addition, since the refrigerant that has cooled the moving blade side fitting portion joins the mainstream gas through the downstream wheel side surface, if the moving blade side fitting portion refrigerant flow rate is large, the mixing loss and pumping loss to the mainstream gas increase and Lowering the mainstream gas temperature leads to lower gas turbine thermal efficiency.

The present invention has been made in view of the foregoing, and has as its object to suppress the wheel metal temperature at the fitting portion between the wheel and the moving blade within an allowable value without using a special device. It is an object of the present invention to provide a gas turbine of this type which can sufficiently suppress a thermal stress generated by a radial temperature difference of a moving blade.

[0011]

That is, according to the present invention, there is provided a moving blade having a refrigerant flow passage therein, and holding the moving blade by concave and convex engagement. A rotating wheel having a refrigerant supply path for supplying
A seal member provided in a gap between the concave and convex engaging portions to prevent leakage of the supplied refrigerant, wherein the moving blade is formed so as to be cooled by the refrigerant supplied from the rotating wheel. In the turbine, a closing plate is provided on one axial end side of the concave-convex engagement portion between the wheel and the moving blade, and a coupling convex portion between the moving blade and the wheel includes
An intended purpose is achieved by providing a leakage refrigerant flow passage penetrating in the axial direction.

Further, according to the present invention, a moving blade having a refrigerant flow passage therein, the moving blade is held by uneven engagement, and refrigerant is supplied to and recovered from the moving blade via the uneven engaging portion. A rotating wheel having a refrigerant supply path and a refrigerant recovery path, and a seal member provided in a gap between the concave and convex engaging portions to prevent leakage of the supplied refrigerant, wherein the moving blade is supplied from the rotary wheel. In the gas turbine, which is cooled by the cooling medium and is formed such that the cooled cooling medium is collected on the wheel side, a blocking plate is provided on one end side in the axial direction of the concave / convex engaging portion between the wheel and the moving blade. A leakage refrigerant flow passage penetrating in the axial direction is provided in the coupling convex portion between the rotor blade and the wheel, and an end of the leakage refrigerant flow passage on the side of the anti-blocking plate is provided as a refrigerant recovery passage of the wheel. To connect One in which the.

A rotor blade having a refrigerant flow passage therein;
A rotating wheel having a coolant supply path and a coolant recovery path for supplying and recovering a coolant to and from the rotor blade via the recess and protrusion engagement portion while holding the rotor blade by the recess and protrusion engagement; And a sealing member provided to prevent leakage of the refrigerant, wherein the rotor blades are cooled by the refrigerant supplied from the rotating wheel, and the cooled refrigerant is collected on the wheel side. In the gas turbine described above, blocking plates are provided at both axial ends of the concave-convex engagement portion between the wheel and the moving blade, and leakage refrigerant flowing through the connecting convex portion between the moving blade and the wheel in the axial direction. A path is provided, and the wheel-side gap of one of the closing plates is formed so as to be connected to the refrigerant recovery path of the wheel.

Further, in this case, the amount of the refrigerant flowing through the leaked refrigerant flow passage is adjusted by adjusting the sealing ability of the sealing member. Further, a protrusion is provided on a side wall near the outer periphery of the wheel, and the closing plate is hooked on the protrusion.

That is, in the gas turbine formed as described above, a closing plate is provided at one axial end of the engaging portion between the wheel and the moving blade, and the connecting protrusion between the moving blade and the wheel is provided. Since the leak refrigerant flow passage is provided in the part,
The coolant that has passed through the seal portion flows through the gap between the engagement portions and the leaked refrigerant flow passage to cool the engagement portion, and therefore, without using a special coolant or a coolant supply device, the wheel and the rotor blade The wheel metal temperature at the engagement portion can be kept within an allowable value, and the thermal stress generated due to the radial temperature difference between the moving blades can be sufficiently suppressed.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows a cross section of a turbine rotor portion of the gas turbine. Reference numerals 1 to 4 are blades, 5 to 8 are wheels, 9 to 11 are spacers, 12 is a distant piece, and 13 is a stub shaft. The arrow 15 indicates the flow of the moving blade cooling air. In addition, as a refrigerant for the moving blade, a gas such as air, water vapor, nitrogen, and hydrogen and a liquid such as water can be considered. Here, the case where air is used as the refrigerant will be described as an example.

The turbine rotor has a single-stage moving blade 1 on its outer peripheral portion.
A first-stage wheel 5, a two-stage wheel 6, a three-stage wheel 7, a four-stage wheel 8, having a two-stage bucket 2, a three-stage bucket 3, and a four-stage bucket 4, and 1 located between the wheels. 2 spacer 9, 2-3 spacer 10, 3-4 spacer 11,
Further, it comprises a distant piece 12 for connecting the turbine wheel and the compressor wheel, and a stub shaft 13 for connecting to the four-stage wheel 8.

The distant piece, the wheel, the spacer, and the stub shaft are stacked in the axial direction, and are tightened in the axial direction by a plurality of stacking bolts 14 at the same radial position to be integrated. The rotor blade has a refrigerant flow passage therein, and is held on the outer periphery of the wheel that rotates by the concave and convex engagement.

Cooling air 15 for cooling the rotor blades is supplied from the shaft end, passes through the center hole of
It reaches the side of the step wheel 8. From the side surface of the four-stage wheel 8, it reaches the upstream side surface of the three-stage wheel 7 through a plurality of holes 16 provided in the circumferential direction so as to penetrate the stacking portions of the wheel and the spacer in the axial direction. Then, here, in order to supply the cooling air of the three-stage moving blade 3, the air is branched and circulated to a slit 30 provided in the side surface of the three-stage wheel 7 in the radial direction.

The cooling air that has reached the downstream side surface of the two-stage wheel 6 through the hole 16 is provided with a slit 17 formed in the side surface of the two-stage wheel 6 in a radial direction to cool the two-stage bucket 2. Branched and distributed. Similarly, the cooling air reaching the side of the first wheel 5 through the hole 16 is
Is supplied to the first-stage moving blade 1 from a hole 20 that reaches the slit 18 provided in the radial direction on the side surface and guides cooling air to each of the plurality of first-stage moving blades 1 through the cavity 19.

The cooling air that has reached the radially provided slit 17 on the side surface of the two-stage wheel 6
The cooling air is supplied to the two-stage moving blade 2 from a hole 22 that guides the cooling air to each of the plurality of two-stage moving blades 2 through the first moving blade 2. Further, the cooling air reaching the slits 30 provided in the side surface of the three-stage wheel 7 in the radial direction passes through the cavity 31 to the three-stage moving blades 3 from the holes 32 for guiding the cooling air to each of the plurality of three-stage moving blades 3. Supplied.
The air that has cooled the three-stage bucket 3 is discharged into the mainstream gas 40.

The air that has cooled the first-stage moving blades 1
A plurality of holes 26 are provided in the circumferential direction so as to penetrate the stacking portion in the axial direction through the holes 23, the cavities 24, and the slits 25 without being discharged to the holes 7 and 38. The air that has cooled the two-stage bucket 2 also does not discharge into the mainstream gas 38, 39, and the hole 2
7. Reach the hole 26 through the cavity 28 and the slit 29. The cooled air that has reached the holes 26 is collected from the distant piece 12 to the outside of the rotor.

On the upstream side of the first-stage moving blade 1, a part of the air 33 that has cooled the first-stage moving blade 1 and the second-stage moving blade 2 and discharged to the outside of the rotor flows and joins the mainstream gas 37. This flow 33 prevents the hot mainstream gas 37 from entering the side surface of the first-stage wheel 5 and the outer peripheral surface of the distant piece 12.
The space between the first wheel 5 and the second wheel 6, the space between the second wheel 6 and the third wheel 7, and the space between the third wheel 7 and the fourth wheel 8 also enter the mainstream gas through the outer casing. The protection air 34, 35, 36 is supplied. The mainstream gas is prevented from entering the outer periphery of the wheel by these intrusion preventing air.

FIG. 2 shows an outer peripheral portion of the first-stage moving blade 1 and the first-stage wheel 5, FIG. 3 shows a fitting portion of the first-stage moving blade 1 and the first-stage wheel 5 shown in FIG. An AA cross section of the fitting portion between the two-stage bucket 2 and the two-stage wheel 6 is shown. FIG.
A gap 50 of about 0.2 mm to 0.3 mm is usually required at the fitting part between the moving blade and the wheel shown in above, in consideration of the assemblability and processing accuracy when inserting the moving blade into the wheel in the axial direction. is there.

A hole 20 for guiding cooling air to each of the first-stage moving blades 1
There is also a gap 50 at the connecting portion 56 of the blade root hole 63 and the sealing member 53, 55 and a part of the high-pressure moving blade supply cooling air merge with the low-pressure moving blade recovery cooling air at the connecting portion 56. Is provided.
FIG. 5 is an external view of the seal members 53, 54, 55. The outer peripheral surface 91 of the seal member is in close contact with the groove of the wheel dovetail, and the side surface 92 is in close contact with the blade groove.

Due to the rotation of the rotor, the centrifugal load of the rotor blade acts on the fitting portion, and the fitting portion gap 50 is reduced from about 0.02 mm to 0.1 mm.
In order to enlarge by 03 mm, the outer peripheral surface 91 of the sealing members 53, 54, 55 is also at least about 0.02 mm to 0.03 m.
m gaps occur. Therefore, a flow 60 of the moving blade supply cooling air toward the wheel upstream side surface, a flow 61 of the moving blade supply cooling air toward the moving blade recovery cooling air, and a flow 62 of the moving blade recovery cooling air toward the wheel downstream side surface occur. become.

A cooling air supply hole 20 provided in the wheel
A side plate (blocking plate) 57 that covers the fitting portion is attached to an outer peripheral hook 58 on the side surface of the wheel near the wheel outer peripheral groove communication position 56.
To prevent the hot metal from passing through the gap 50 in the axial direction from the upstream to the downstream of the working gas in the axial direction, thereby preventing the metal temperature of the wheel outer peripheral portion from exceeding the allowable temperature. I have.

The flow 60 of the moving blade supply cooling air toward the upstream side of the wheel flows into the cavity 66 formed by the side plate 57, the moving blade and the wheel, and the fitting portion gap 50 is moved from the upstream to the downstream of the mainstream gas flow. And is discharged outside the rotor. By using the side plate 57, the fitting portion can be cooled using the leakage air of the moving blade cooling air.

When the sealing member 53 is not provided, the pressure in the cavity 66 is substantially equal to the pressure of the moving blade cooling air because the gap 50 of the fitting portion is as large as about 0.2 to 0.3 mm. Therefore, there is a possibility that a large amount of cooling air passes through the fitting portion gap 50 so that the fitting portion on the moving blade side becomes overcooled. If the blade cooling air temperature is set to 300 ° C. and the metal temperature is reduced to about 300 ° C. due to supercooling of the fitting part on the blade side, since the temperature of the portion in contact with the working gas is about 900 ° C. at the maximum, A maximum temperature difference of 600 ° C. occurs in the radial direction of the moving blade, and this temperature difference causes a problem of thermal stress acting on the moving blade.

Further, in the case of the single-stage rotor blade 1, a large amount of cooling air merges with the mainstream gas 37, so that the mixing loss and the pumping loss to the mainstream gas increase and the temperature of the gas turbine decreases because the mainstream gas temperature decreases. Leads to a decline.
Therefore, the flow path resistance is increased by installing the seal member 53 and making the gap between the outer peripheral surfaces 91 smaller, so that the cavity 66
Is lower than the pressure of the moving blade cooling air, and the flow rate passing through the fitting portion gap 50 is suppressed.

The two-stage bucket 2 and the two-stage wheel 6 shown in FIG.
Are also provided with seal members 70 and 72 and a seal member 71 for preventing the high-pressure moving blade supply cooling air from joining the low-pressure moving blade recovered cooling air. Further, a side plate 74 covering the fitting portion is provided between the outer hook 75 and the inner hook 76 on the downstream side surface of the cooling air supply hole 22 provided in the wheel near the wheel outer circumferential groove communication position 73. This prevents the high temperature gas from passing through the fitting portion gap 50 in the axial direction from the upstream to the downstream of the working gas and preventing the metal temperature of the wheel outer peripheral portion from exceeding the allowable temperature.

Further, by introducing the blade supply cooling air 78 that has passed through the seal member 72 to the cavity 77 formed by the side plate 74 and the two-stage bucket 2 and the two-stage wheel, the fitting section gap 50 is reduced to about 300 ° C. Low temperature air will pass axially from downstream to upstream of the working gas. By installing the seal member 72 and reducing the gap between the outer peripheral surfaces 91, the flow path resistance is increased, the pressure in the cavity 77 is made lower than the pressure of the moving blade cooling air, and the flow rate passing through the fitting portion gap 50 is suppressed. This prevents overcooling of the two-stage wheel two-blade side fitting portion.

Further, a gap for setting the amount of passing air is previously provided between the seal member 53 for cooling cooling air supplied to the first stage and the sealing member 72 for cooling air supplied to the second stage and the wheel groove, so that the blade-side fitting is achieved. It is also possible to adjust the metal temperature of the part and the wheel side fitting part.

FIG. 6 is a view of the fitting portion between the first-stage moving blade 1 and the first-stage wheel 5 as viewed from the upstream side surface. A view of the fitting portion between the two-stage bucket 2 and the two-stage wheel 6 as viewed from the downstream side is also the same as FIG. A plurality of side plates 57 (in the present embodiment, the number of blades) are provided in a groove formed by an outer peripheral hook (projecting portion) 58 and an inner peripheral hook 59.

In this case, at least one portion of the entire circumference does not have the inner peripheral side hook 59, and a side plate insertion portion 100 which is further cut into the inner peripheral side is provided (FIG. 7 showing a cross section taken along line BB of FIG. 6). ), The side plate 57 is axially inserted into the side plate insertion point 100, and when it reaches the inside of the outer peripheral hook 58, it is moved in the outer peripheral direction to match the outer peripheral hook groove. Then, as shown in FIG. 6, the outer peripheral hook 58 and the inner peripheral hook 59 are attached by sliding in a circumferential direction in a groove formed by the hook.

The side plate 57 is fixed by the outer peripheral hook 58 by centrifugal force during rotation. The outer peripheral hook 58 includes a rotor blade outer peripheral hook 58a and a wheel outer peripheral hook 58b.
7 prevents the blade from moving in the axial direction and prevents the blade from falling off the wheel. The side plate 57 contacts the wheel outer peripheral hook 58b when rotating, and the rotor blade outer peripheral hook 58b.
By not making contact with a, it is possible to prevent the side plate 57 from affecting the natural frequency of the moving blade.
In other words, it is possible to prevent an increase in the blade natural frequency analysis error.

In FIG. 8, the inner periphery of the side plate 57 and the inner periphery hook 59 are provided with a tapered portion so that the side plate 57 is restrained by the centrifugal force on the wheel so that the outer periphery hook 58a and the wheel outer periphery hook 58b are not contacted. I have. The method shown in FIG. 8 can also prevent the side plate 57 from affecting the natural frequency of the moving blade. In FIG. 9, a hole communicating with the inner peripheral hook 59 and the inner peripheral side of the side plate 57 is provided.
5, the side plate 57 is fixed to the inner peripheral hook 59 of the wheel via the fixing pin 95. Even in the method shown in FIG. 9, the side plate 57 does not come into contact with the outer peripheral hook 58, so that the natural frequency of the moving blade is not affected.

FIG. 10 shows a state where the mounting of the side plate 57 is completed. When the last one side plate is mounted, the side plates are all inserted except for the side plate insertion portion 100. Since the inner hook 59 is not provided at the side plate insertion portion 100, the side plate easily falls off even if the last side plate is attached to the side plate insertion portion 100. If you fall off while driving, it will lead to a major accident. Therefore, as shown in FIG.
By inserting one side plate into the side plate insertion portion 100 and moving all the side plates in the circumferential direction by a half pitch of the side plates, all the side plates are fixed in the axial direction. The side plate moves in the circumferential direction during operation from the state where the mounting is completed, and the side plate insertion portion 10
0 to prevent the side plate from falling off
1, 102 are provided.

FIGS. 11 and 12 show the connecting portion 103 between the side plates viewed from the radial direction. In FIG. 11, when the pressure in the cavity 66 is higher than the pressure on the upstream side surface of the one-stage moving blade in FIG.
It is possible to suppress the amount of cooling air leaking from 6 to the first rotor blade upstream side surface.

When the pressure in the cavity 66 is lower than the pressure on the upstream side surface of the first stage blade, the amount of high-temperature air leaking from the upstream side surface of the first stage blade into the cavity 66 can be suppressed. In FIG. 12, the protruding portions 110 and 111 from the side plates 108 and 109 have a hook shape, and can suppress the amount of leaked air and restrict the movement in the circumferential direction similarly to FIG. It is possible to prevent the mass imbalance in the circumferential direction due to the increase in the gap of the connection portion 103 of the first embodiment. By preventing mass imbalance, axial vibration of the rotor can be suppressed.

FIG. 13 shows the cooling air and 3
The flow of cooling air to the fitting portion between the step wheel 7 and the three-stage bucket 3 is shown. The point that the cooling method of the three-stage moving blade 3 is different from the one-stage and the two-stage moving blade is that the air after cooling is discharged into the mainstream gas, and the air after the cooling of the moving blade is applied to the fitting portion between the moving blade and the wheel. The point that does not come back. Therefore, although the seal members 124 and 125 for adjusting the flow of air to the side surface of the wheel are necessary, a seal member between the blade cooling supply air and the recovered air is not necessary.

Further, the coolant supply passage 3 provided in the wheel
The outer peripheral side surface 126 of the 2-3 spacer 10 is used as a side plate for covering the wheel outer peripheral groove and the root of the moving blade fitted into the groove on the wheel side surface near the wheel outer peripheral groove communication position 120 of No. 2. The air 127 that has passed through the seal member 124 flows into a cavity 131 formed by the outer peripheral side surface 126 and the fitting portion side surface, and is discharged from the outer periphery of the rotor 128 and the flow 128 that is discharged from the rotor outer peripheral surface through the fitting portion clearance. Branch to 130.

In this method, as in the cooling method for the one-stage and two-stage fitting portions, the mainstream gas is prevented from entering the fitting portion, and air depressurized by the seal member 124 is introduced into the fitting portion. can do.

FIG. 14 shows an embodiment of a sealing structure different from the sealing method shown in FIG. Hole 2 in the wheel
Sealing members 150 and 151 are inserted into portions connecting the holes 0 and 23 with the holes 63 and 64 provided in the rotor blade. The seal members 150 and 151 have a ring shape and seal by sealing the connection portion in the ring.

FIG. 15 shows an embodiment in which the air after the cooling of the fitting portion is collected by the wheel. The air 60 that has passed through the seal member 53 flows into the cavity 59 formed by the side plate 57 and the moving blade 1, flows through the clearance between the moving blade and the fitting portion of the wheel, and cools (arrows 160 and 161). The cooled air flows into the cavity 162 formed by the side plate 163 and the moving blade 1 provided on the opposite side of the side plate 57, and flows into the hole 23 for collecting the air that has cooled the moving blade 1 (arrow 164).

In this embodiment, since the air after cooling the fitting portion is not discharged to the outside of the wheel, but is recovered to the wheel together with the air after cooling the moving blades, the air discharged to the mainstream gas is reduced, and the thermal efficiency of the gas turbine is reduced. Is improved.

As described above, the gas turbine formed as described above has a seal structure at the connection between the flow path provided in the wheel and the flow path at the root of the blade, and passes through the seal structure. Cooling the gap between the moving blade and the wheel by using the decompressed moving blade refrigerant allows the metal temperature at the wheel-side fitting part to be low, lowering the allowable stress of the wheel metal. Can be suppressed. Furthermore, since there is no need to introduce a coolant dedicated to cooling the fitting portion other than the moving blade cooling coolant, the structure is simple.

Further, since the moving blade refrigerant which has been depressurized by passing through the seal structure is used, the amount of the refrigerant passing through the fitting portion can be suppressed, and the rotor blade side fitting portion is prevented from being overcooled.
That is, since the temperature gradient generated in the radial direction of the moving blade can be reduced, the thermal stress generated in the moving blade can be reduced. Further, the mixing loss and pumping loss to the mainstream gas are reduced, and the amount of decrease in the temperature of the mainstream gas is also reduced, so that the thermal efficiency of the gas turbine is increased.

Further, a side plate for covering the wheel outer peripheral groove and the root of the moving blade fitted into the groove is provided on the side surface of the wheel near the wheel outer peripheral groove communicating position of the refrigerant supply flow path provided in the wheel, thereby providing a seal. It is possible to form a flow path in which the refrigerant that has passed through the structure flows in the gap between the moving blade and the wheel in the axial direction from the wheel side surface with the side plate to the wheel side surface without the side plate on the opposite side. Can be accurately supplied to the required gap of the fitting portion, and the reliability can be improved.

[0050]

As described above, according to the present invention, the temperature of the wheel metal at the fitting portion between the wheel and the moving blade can be suppressed to an allowable value without using a special device. This type of gas turbine that can sufficiently suppress the thermal stress generated by the radial temperature difference between the moving blades can be obtained.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing one embodiment of a turbine section and a rotor blade support section of a gas turbine of the present invention.

FIG. 2 is a vertical sectional side view showing one embodiment of a turbine section of the gas turbine of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view of a fitting portion between a gas turbine blade and a wheel according to an embodiment of the present invention.

FIG. 5 is a perspective view showing an appearance of a gas turbine blade cooling air sealing member according to an embodiment of the present invention.

FIG. 6 is a side view of a fitting portion between a gas turbine blade and a wheel according to an embodiment of the present invention.

FIG. 7 is an insertion view of a side plate (blocking plate) according to an embodiment of the present invention.

FIG. 8 is a sectional view of a fitting portion between a gas turbine blade and a wheel according to an embodiment of the present invention.

FIG. 9 is a sectional view of a fitting portion between a gas turbine blade and a wheel according to an embodiment of the present invention.

FIG. 10 is a side view of a fitting portion between a gas turbine rotor blade and a wheel according to an embodiment of the present invention.

FIG. 11 is a side view showing a connecting portion between side plates according to an embodiment of the present invention.

FIG. 12 is a side view showing a connection portion between side plates according to an embodiment of the present invention.

FIG. 13 is a sectional view of a fitting portion between a gas turbine blade and a wheel according to an embodiment of the present invention.

FIG. 14 is a cross-sectional view of a fitting portion between a gas turbine blade and a wheel according to an embodiment of the present invention.

FIG. 15 is a sectional view of a fitting portion between a gas turbine blade and a wheel according to an embodiment of the present invention.

[Explanation of symbols]

1-4: rotor blade, 5-8: wheel, 9-11: spacer, 12: distant piece, 13: stub shaft, 50: fitting part gap, 53: seal member, 56: hole in wheel outer peripheral groove Communication position, 57 ... side plate, 58 ...
Outer peripheral hook, 58a ... bucket outer peripheral hook, 58b ... wheel side outer hook, 59 ... inner peripheral hook, 66 ... cavity, 72 ... seal member, 74 ... side plate, 75 ... outer peripheral hook, 76 ... inner peripheral hook, 77 ... cavity , 91: outer peripheral surface of the seal member, 95: fixing pin, 100: insertion portion of the side plate, 101: circumferential stop pin, 102: circumferential stop pin, 103: connecting portion of the side plate, 124: seal member,
126 ... side plates, 150, 151 ... seal members.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Ikeguchi 7-2-1, Omika-cho, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Power and Electricity Development Division (72) Inventor Kazuhiko Kawaike Omika-cho, Hitachi City, Ibaraki Prefecture 7-2-1, F-term (Reference), Power & Electricity Development Division, Hitachi, Ltd. 3G002 AA06 AB01 CA06 CA08 CA10 CB01 FA04 FA09 FB04 HA07 HA08 HA18

Claims (5)

[Claims] 1. A rotating blade having a refrigerant flow passage therein, and having a refrigerant supply passage for holding the moving blade by concave and convex engagement and supplying a refrigerant to the moving blade via the concave and convex engaging portion. A wheel, provided in a gap between the concave and convex engaging portions,
A gas turbine comprising: a sealing member for preventing leakage of the supply refrigerant; and wherein the moving blade is formed so as to be cooled by a refrigerant supplied from the rotating wheel. A gas turbine characterized in that a closing plate is provided on one end side in the axial direction of the engaging portion, and a leaking refrigerant flow passage penetrating in the axial direction is provided in a coupling convex portion between the rotor blade and the wheel. . 2. A moving blade having a refrigerant flow passage therein, and a refrigerant supply path for holding and moving the moving blade by concave and convex engagement, and supplying and recovering refrigerant to and from the moving blade via the concave and convex engaging portion. A rotating wheel having a refrigerant recovery path, and a seal member provided in a gap between the concave and convex engaging portions to prevent leakage of the supplied refrigerant, wherein the rotor blade is cooled by the refrigerant supplied from the rotating wheel. And, in the gas turbine is formed so that the refrigerant after cooling is collected on the wheel side, while providing a blocking plate on one axial end side of the uneven engagement portion between the wheel and the rotor blade, Providing a leakage refrigerant flow passage penetrating in the axial direction in the coupling convex portion of the rotor blade and the wheel,
A gas turbine, wherein an end of the leaked refrigerant flow passage on the side opposite to the blocking plate is connected to a refrigerant recovery passage of the wheel. 3. A rotor blade having a refrigerant flow passage therein, a refrigerant supply path for holding the rotor blade by concave and convex engagement, and supplying and recovering refrigerant to and from the rotor blade via the concave and convex engagement portion. A rotating wheel having a refrigerant recovery path, and a seal member provided in a gap between the concave and convex engaging portions to prevent leakage of the refrigerant, wherein the rotor blades are cooled by a refrigerant supplied from the rotating wheel. And a gas turbine formed so that the cooled refrigerant is collected on the wheel side. In the gas turbine, closing plates are provided at both axial ends of a concave-convex engagement portion between the wheel and the moving blade, and the moving blade A leakage refrigerant flow passage penetrating in the axial direction at the coupling convex portion of the wheel and the wheel, and formed so as to connect the wheel-side gap of one of the closing plates to the refrigerant recovery passage of the wheel. You Gas turbine. 4. The gas turbine according to claim 1, wherein an amount of the refrigerant flowing through the leakage refrigerant flow passage is adjusted by adjusting a sealing ability of the seal member. 5. The gas turbine according to claim 1, wherein a projection is provided on a side wall near an outer periphery of the wheel, and the closing plate is hooked on the projection.