JP3858445B2 - Compressor rotor internal bleed structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a compressor rotor that is a constituent element of a gas turbine, and more particularly to a compressor rotor that bleeds a part of a working fluid to a turbine side through a space of a rotor central portion.
[0002]
[Prior art]
FIG. 2 shows a general structural sectional view of a gas turbine. The gas turbine is roughly composed of a compressor 1 ', a combustor 2' and a turbine 3 '. The compressor 1 'adiabatically compresses the air sucked from the atmosphere into the gas path 4' as a working fluid, and the combustor 2 'mixes fuel with the compressed air supplied from the compressor 1' and burns it, thereby causing high-temperature and high-pressure gas. And the turbine 3 'generates rotational power during expansion of the combustion gas introduced from the combustor 2'. Exhaust from the turbine is released into the atmosphere. The remaining power obtained by subtracting the power for driving the compressor 1 from the rotational power generated in the turbine 3 'becomes the power generated by the gas turbine and drives the generator.
[0003]
The rotor of the compressor is composed of rotor disks stacked in multiple stages from upstream to downstream of the working fluid (air). That is, the foremost rotor disk 5 ′ having a rotating shaft extending forward, the last rotor disk 6 ′ having a rotating shaft extending rearward, and an intermediate rotor disk 7 sandwiched between the foremost and last rotor disks. ′.
[0004]
Since the working fluid flowing through the gas path 4 from the front to the rear increases in temperature every time it passes through the rotor disk by adiabatic compression by the compressor 1 ′, the outer periphery of the rotor disk on the rear stage side of the compressor is exposed to a high temperature environment. It is. Therefore, it is necessary to use a material having high strength in a high temperature environment as a material for the compressor rear stage rotor disk. However, since this type of high-temperature high-strength material is an expensive alloy material such as a Ni-based alloy, it is required to cool the rotor disk in order to reduce the cost by using low alloy steel.
[0005]
On the other hand, a turbine rotor disk is fitted with a larger blade than the compressor blade on the outer peripheral portion thereof, so that the rotor disk is larger than the compressor in order to withstand the centrifugal force generated by the blade. Accordingly, the heat capacity inevitably increases, and even after the gas turbine is started, the center portion of the turbine rotor disk is at a lower temperature than the outer peripheral portion, and a large tensile thermal stress acts on the center portion. This phenomenon also occurs to some extent in the compressor rotor disk.
[0006]
In order to solve the above two problems, a part of the low-temperature working fluid flowing in the gas path is extracted into the compressor rotor disk, led from the compressor rotor disk to the turbine rotor disk, and from the turbine rotor disk. By discharging to the outside, it is effective to have a structure that warms up the rotor disk at startup and cools it down during rating.
[0007]
One example of such a rotor disk internal bleed structure is the gas turbine rotor structure of the Siemens gas turbine V64.3. FIG. 3 is a structural cross-sectional view of the turbine section of the known example. This gas turbine rotor is a stacked rotor in which a rotor disk with a plurality of rotor blades attached to the outer periphery is stacked in the direction of the rotation axis in multiple stages. In the figure, the left side is the upstream front stage side, and the right side is the downstream rear stage side. 1 is a rotor disk, 2 is a moving blade and is attached to the outer periphery of the rotor disk 1, 3 is a stationary blade, and 4 is a shroud to constrain the tip of the stationary blade 3.
[0008]
In construction, a bleed hole group 5 is provided from the outer peripheral part of the compressor rotor disk to the center part, and the working fluid extracted through the hole group 5 is guided to the center part of the rotor disk. The medium guided to the center is warmed up at the time of starting the compressor and turbine rotor disk 1 and cooled at the time of rating, and then discharged to the outside of the rotor disk. Thus, the cost is reduced by using low alloy steel, and the heat stress is reduced. A reliable structure is realized.
[0009]
[Problems to be solved by the invention]
In recent years, gas turbine equipment has been required to improve the efficiency of the system for the purpose of energy saving and environmental protection, and to reduce the cost in order to cope with market competition.
[0010]
As means for increasing efficiency, there is a tendency to increase the pressure ratio of the compressor and increase the turbine inlet temperature.
[0011]
Compared to the conventional gas turbine, the temperature of the outer periphery of the compressor rotor disk increases due to the higher pressure ratio of the compressor, and the temperature of the outer periphery of the turbine rotor disk tends to increase due to the increase of the turbine inlet temperature. Therefore, the rotor disk is expected to be exposed to a higher temperature environment in the future, and it is expected that improvement in cooling capacity will be inevitably required.
[0012]
Also, due to the temperature rise at the outer periphery of the compressor rotor disk, the temperature difference between the inner and outer periphery of the rotor disk at the time of start-up tends to increase and excessive thermal stress tends to occur. Therefore, it is expected that at the time of start-up, it is required to reduce the temperature difference between the inside and outside of the rotor disk and suppress the thermal stress by warming up the inside of the rotor.
[0013]
For the above problem, as in the conventional technique shown in FIG. 3, in a structure in which a part of the working fluid flowing in the gas path is extracted using a hole that is linearly connected from the outer peripheral surface of the rotor disk to the inside, The temperature difference between the rotor disk provided with the bleed holes and the disk not so becomes large, which causes generation of stress due to the thermal expansion difference. Further, the fact that all of the extracted working fluid flows in the center hole of the rotor disk generates a temperature distribution in the radial direction on the rotor disk, which causes generation of thermal stress.
[0014]
An object of the present invention is to achieve a compressor rotor that solves the above-mentioned problems and realizes a cost reduction due to the adoption of low alloy steel by strengthening cooling at the time of rating and a highly reliable structure by reducing thermal stress at the time of start-up. Is to provide.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, a first compressor rotor of the present invention includes a foremost rotor disk having a rotating shaft extending forward and having a plurality of blades attached to the outer periphery, and a plurality of rotor rotors on the outer periphery. A rotor disk group having blades attached thereto and a last stage rotor disk having a rotating shaft extending rearward and having a plurality of rotor blades attached to the outer periphery thereof.
[0016]
The rotor disks are sequentially arranged from the upstream side to the downstream side of the intake air, and the side surfaces of the annular hub part forming the outer peripheral part of the rotor disks are in close contact with each other and are penetrated and fastened by stacking bolts.
[0017]
Further, of the adjacent rotor disks, one rotor disk has a circular recess on one side along the inner periphery of the annular hub part, and the other rotor disk has an annular protrusion on the opposite surface near the inner periphery of the annular hub part. The two rotor disks are constrained in the radial direction by being fitted into the circular indentations.
[0018]
In the first compressor rotor disk, the annular hub portion is provided with a circular hole continuously passing through the plurality of rotor disks in parallel to the rotation center axis, and the rotation hub axis is formed in the annular hub portion so as to intersect the circle hole. It is possible to evenly bleed a part of the low-temperature working fluid that flows through the compressor gas path across multiple stages from the annular hub part of the compressor rotor disk to the inside by providing a radially provided groove from It is possible to improve reliability by warm-up operation at startup and cooling at rated time.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The compressor rotor according to the present invention includes a plurality of rotor blades each receiving work from a fluid, a plurality of rotor disks in which the rotor blades are implanted along the outer periphery, and a plurality of stacked rotor disks. And stacking bolts to be fastened. The foremost rotor disk has a rotating shaft extending forward, and the last rotor disk has a rotating shaft extending rearward.
[0020]
The rotor blade has a dovetail projecting on both sides from the root of the blade portion, and the rotor disk has an appropriate angle in the rotational axis direction or the circumferential direction on its outer peripheral portion in order to fit the dovetail of the rotor blade. Grooves are cut.
[0021]
Each rotor disk has an inner peripheral portion thicker than the outer peripheral portion, and further, an annular hub portion is formed on the inner peripheral side in the vicinity of the outer periphery, and the adjacent rotors are brought into close contact with each other. While overlapping with the disk, a circular recess formed on the side surface of one adjacent hub portion and an annular protrusion formed on the side surface of the other hub portion are fitted in an axial hole manner.
[0022]
Furthermore, each rotor disk has a group of holes equally spaced in the circumferential direction from the center axis of rotation, respectively, and by passing through stacking bolts to each of these groups of holes and fastening via a hub part, A plurality of stages of rotor disks are stacked and fixed in the axial direction. Embodiments of the present invention will be described below with reference to the drawings.
[0023]
FIG. 1 is a sectional view and a side view in the direction of the rotational axis of a rotor disk single stage of a compressor for a gas turbine that best represents the features of the present invention as Embodiment 1 of the present invention, and FIG. 4 is a conventional rotor. FIG. 5 is a cross-sectional view and a side view of a single stage of the disk in the direction of the rotation axis, and FIG. The arrows in the figure indicate the flow of the extracted fluid.
[0024]
As shown in FIGS. 1 and 4, the rotor blade 2 is fixed by implanting a dovetail 6 provided at the base portion into a dovetail groove 7 formed in the outer peripheral portion of the rotor disk 1.
[0025]
As shown in FIGS. 1, 4, and 5, the outer peripheral portion of each rotor disk 1 is formed by an annular hub portion 8, and each rotor disk 1 and the adjacent rotor disk 1 ′ are formed by the annular hub portion 8. The side surfaces 9 are brought into contact with each other to be superimposed. A circular recess 10 (circular inner diameter D) is provided along the inner periphery of the annular hub portion 8 of one rotor disk 1, and projects from the hub portion side surface 9 in the vicinity of the inner periphery of the annular hub portion 8 of the other rotor disk 1 '. An annular projection 11 (ring outer diameter d) is provided.
[0026]
The two rotor disks 1 and 1 ′ are connected to each other by fitting the circular protrusion 11 (ring outer diameter d) of the other rotor disk 1 ′ to the circular recess 10 (circular inner diameter D) of one rotor disk 1. Restrained in the radial direction. Further, the annular hub portion 8 of each rotor disk 1 is formed with a bolt hole 13 having the same radial position from the rotation center shaft 12, and a stacking bolt 14 passes therethrough and is tightened at both ends by nuts 15. Is fastened, and the rotor disk 1 is restrained in the direction of the rotation axis.
[0027]
The structure of the compressor rotor of the present invention has a plurality of types of flow paths for extracting a part of the working fluid flowing through the gas path of the compressor into the compressor rotor disk as shown in FIG. .
[0028]
As shown in FIGS. 1 and 5, a part of the working fluid flowing in the gas path of the compressor is separated from the rotor disk outer peripheral cavity 16 through a gap 17 formed by providing a gap between the rotor disk outermost peripheral part 16 and the adjacent 16 '. 18 leads to. Furthermore, it reaches the annular hub portion by being guided to the groove 19 provided on the side surface of the annular hub portion. In the annular hub portion, a part is guided to the circular hole 20 passing through the plurality of rotor disks continuously in parallel with the central axis of rotation of the annular hub portion, and the remaining portion is rotated to the annular hub portion so as to intersect the circular hole 20. From the groove 21 provided radially from the central axis, it is guided into the rotor disk.
[0029]
As shown in FIG. 6, the bleed fluid introduced into the circular hole 20 is sequentially branched in grooves 21 provided radially from the rotation center axis to the annular hub portion so as to intersect with the circular hole 20, and finally bleed. All the fluid is once collected inside the rotor disk and then guided to the turbine side.
[0030]
As shown in FIG. 7, the groove 19 provided on the side surface of the annular hub portion and the groove 21 provided radially from the center axis of rotation to the annular hub portion so as to intersect the circular hole 20 rotate the rotor disk. Therefore, by processing in a spiral shape, it is possible to reduce the pressure loss of the extraction fluid and improve the thermal efficiency of the entire gas turbine.
[0031]
As described above, the working fluid flowing in the compressor gas path can be uniformly extracted into the compressor rotor disk, and the reliability of the rotor disk can be improved by performing the role of warm-up operation during startup and cooling during rating. It is possible to improve.
[0032]
Further, Embodiment 2 of the present invention is shown in FIG. The arrows in the figure indicate the flow of the extracted fluid.
[0033]
As shown in FIGS. 5 and 8, a part of the working fluid flowing in the gas path of the compressor is separated from the rotor disk outer peripheral cavity by a gap 17 formed by providing a gap between the rotor disk outermost peripheral part 16 and the adjacent 16 '. 18 leads to. In the outer peripheral cavity 18, a part is guided to a circular hole 22 that continuously passes through a plurality of rotor disks in parallel with the rotation center axis, and the remaining part is from a groove 23 provided radially from the rotation center axis in the annular hub portion. , Guided into the rotor disk.
[0034]
The bleed fluid guided to the circular holes 22 is sequentially branched in the respective outer peripheral cavities, and finally, all the bleed fluid is temporarily passed into the rotor disk through the grooves 23 provided radially from the central axis of rotation in the annular hub portion. After being collected, it is led to the turbine side.
[0035]
As shown in FIG. 9, the groove 23 provided on the side surface of the annular hub portion is processed into a spiral shape in consideration of the rotation of the rotor disk, thereby reducing the pressure loss of the bleed fluid, The thermal efficiency of the entire gas turbine can be improved.
[0036]
As described above, the working fluid flowing in the compressor gas path can be uniformly extracted into the compressor rotor disk, and the reliability of the rotor disk can be improved by performing the role of warm-up operation during startup and cooling during rating. It is possible to improve.
[0037]
Further, Embodiment 3 of the present invention is shown in FIG. The arrows in the figure indicate the flow of the extracted fluid.
[0038]
As shown in FIGS. 5 and 10, a part of the working fluid flowing in the gas path of the compressor is separated from the rotor disk outer peripheral cavity by a gap 17 formed by providing a gap between the rotor disk outermost peripheral part 16 and the adjacent 16 '. 18 leads to. In the outer peripheral cavity 18, a part is led to the dovetail groove 7, and the remaining part is led to the inside of the rotor disk from a groove 23 provided radially on the annular hub part from the rotation center axis.
[0039]
The bleed fluid guided to the dovetail groove 7 is sequentially branched in each outer peripheral cavity, and finally, all the bleed fluid is temporarily passed into the rotor disk through the grooves 23 provided radially from the rotation center axis in the annular hub portion. After being collected, it is led to the turbine side.
[0040]
As shown in FIG. 9, the groove 23 provided on the side surface of the annular hub portion is processed into a spiral shape in consideration of the rotation of the rotor disk, thereby reducing the pressure loss of the bleed fluid, The thermal efficiency of the entire gas turbine can be improved.
[0041]
As described above, the working fluid flowing in the compressor gas path can be uniformly extracted into the compressor rotor disk, and the reliability of the rotor disk can be improved by performing the role of warm-up operation during startup and cooling during rating. It is possible to improve.
[0042]
【The invention's effect】
According to the present invention, in the compressor rotor disk of the present invention, the annular hub portion is provided with a circular hole penetrating through the plurality of rotor disks in parallel to the rotation center axis, and intersects with the circular hole. By providing a groove provided radially from the rotation center axis, it is possible to uniformly bleed the working fluid on the low temperature side flowing through the compressor gas path into the compressor rotor disk, warming up operation at the start, rated It is possible to improve the reliability by cooling at the time.
[Brief description of the drawings]
FIG. 1 is a diagram best showing the structure of a compressor rotor according to a first embodiment of the present invention.
FIG. 2 is a structural sectional view of a general gas turbine.
FIG. 3 is a structural cross-sectional view of a gas turbine that enables conventional rotor internal bleed.
FIG. 4 is a view showing a single-stage structure of a rotor disk.
FIG. 5 is a diagram showing a structure in which a plurality of compressor rotors according to Embodiment 1 of the present invention are stacked.
FIG. 6 is a diagram showing a structure of a compressor rotor according to the first embodiment of the present invention.
FIG. 7 is a diagram showing another example of the structure of the compressor rotor according to the first embodiment of the present invention.
FIG. 8 is a diagram showing a structure of a compressor rotor according to a second embodiment of the present invention.
FIG. 9 is a view showing another example of the structure of the compressor rotor according to the second embodiment of the present invention.
FIG. 10 is a diagram showing a structure of a compressor rotor according to a third embodiment of the present invention.
FIG. 11 is a view showing another example of the structure of the compressor rotor according to the third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rotor disk, 2 ... Moving blade, 3 ... Static blade, 4 ... Shroud, 5 ... Extraction hole group, 6 ... Dovetail, 7 ... Dovetail groove, 8 ... Annular hub part, 9 ... Annular hub side surface,
DESCRIPTION OF SYMBOLS 10 ... Circular dent part, 11 ... Ring-shaped projection part, 12 ... Center axis of rotation, 13 ... Bolt hole, 14 ... Stacking bolt, 15 ... Nut, 16 ... Outermost part of rotor disk,
17 ... Rotor disk outer peripheral gap, 18 ... Rotor disk outer peripheral cavity, 19 ... Outer peripheral side annular hub part side groove, 20 ... Annular hub part through circular hole, 21 ... Inner peripheral side annular hub part side groove, 22 ... Through circular hole, 23: An annular hub side groove.

Claims (1)

A front-stage rotor disk having a rotation center axis extending forward and having a plurality of rotor blades attached to the outer periphery via dovetail grooves, and a rotor disk having a plurality of rotor blades attached to the outer periphery via dovetail grooves The group and the last stage rotor disk having a rotating shaft extending rearward are sequentially arranged from the upstream side to the downstream side of the intake air, and the side surfaces of the annular hub part forming the outer peripheral part of each rotor disk are brought into close contact with each other. The rotor disk is fastened with stacking bolts, and one of the adjacent rotor disks is provided with a circular indentation along the inner circumference of the annular hub part on one side of the rotor disk, and the other rotor disk has an annular surface on the opposite side. A compressor rotor disk in which an annular protrusion is provided near the inner periphery of the hub, the annular protrusion is fitted into the circular recess, and both rotor disks are constrained in the radial direction. A circular hole that is provided in the annular hub portion in parallel with the rotation center axis, and that continuously passes through the plurality of rotor disks, and is provided radially from the rotation center axis to intersect the circular hole. A compressor rotor characterized in that a working fluid can be extracted by using a groove.

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