JP3801344B2 - Gas turbine cooling vane - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas turbine cooling stationary blade provided with a sealing air supply passage for supplying sealing air from the outer peripheral side to the inner peripheral side of the stationary blade.
[0002]
[Prior art]
An outline of this conventional gas turbine cooled stationary blade will be described with reference to FIGS. 3 and 4.
[0003]
FIGS. 3 and 4 show different conventional examples, both of which are shown in cross section so that the supply path of the sealing air becomes clear, and (a) is a longitudinal section of the stationary blade, and (b) ) Shows the cross section.
[0004]
The actual number of gas turbines is determined by the capacity. For example, in the case of a four-stage configuration, the second stage, the third stage, and the fourth stage stationary blades have moving blades arranged at the front and rear, respectively. Since the stator blades are sandwiched between the rotor blades and the rotor disk that supports them, the mainstream high-temperature gas flows into the gaps inside the stator blades formed here for convenience of production, assembly, etc. It is important that there is no.
[0005]
As a countermeasure, normally, the bleed air from the compressor is supplied from the outer periphery of the stationary blade to the cavity on the inner periphery of the stationary blade through the inside of the stationary blade, and the pressure in this cavity is higher than that of the mainstream high-temperature gas passage Thus, a structure that prevents the mainstream hot gas from entering is adopted.
[0006]
An example of a conventional seal air supply structure is a structure in which seal air is supplied using a seal tube 4 as shown in FIG. 3, and the seal tube 4 is a leading edge inside the blade portion 5 from the outer peripheral side of the blade. The first row cooling passage A provided in the blade is penetrated at a position away from the inner surface of the blade portion 5, and the blade outer peripheral side is communicated with the cavity portion on the blade inner peripheral side. In this structure, air 3 is guided.
[0007]
Here, 2 is a cooling medium supplied to cool the stationary blades, from the first row cooling passage A inside the blade portion 5 through the second row cooling passage B and the third row cooling passage C, Released from the blade trailing edge into the mainstream hot gas.
[0008]
Further, the other conventional example shown in FIG. 4 does not employ a seal tube as in the example shown in FIG. 3, but omits the seal tube, and instead directly serves as the blade cooling. The seal air 3 is supplied to the row cooling passage A.
[0009]
[Problems to be solved by the invention]
In the above-described conventional first example, the dedicated seal tube 4 disposed at a position away from the inner surface of the wing part 5 is used to guide the seal air 3, so in this system, The sealing air 3 does not directly contact the inner surface of the wing part 5 and the sealing air 3 has an advantage that it can be supplied as sealing air without heat exchange. However, on the other hand, the sealing tube 4 is used. It had the disadvantage of increasing the number of parts and increasing the number of processing steps.
[0010]
Further, in the conventional second example described above, since the seal tube 4 is not employed, the number of parts and the number of processing steps can be reduced, but the supply path of the seal air 3 is heated. Since the leading edge has a high load, there is a problem that the amount of heat exchange for cooling the blade is large and the seal air temperature becomes too high.
[0011]
The present invention eliminates these problems in the prior art, and can guide and supply sealing air without increasing the number of parts and processing steps while maintaining a low temperature by suppressing the heat exchange amount of the sealing air. It is an object of the present invention to provide a gas turbine cooled stationary blade.
[0012]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems. A plurality of cooling passages extending in the radial direction are formed inside the stationary blade, and a part of the cooling passage is supplied to the cavity on the inner circumferential side from the outer circumferential side of the stationary blade. In the gas turbine cooling stationary blade used as the supply passage for the sealing air to be sealed, the cooling passage in the first row from the upstream side covers both the inner peripheral side and the outer peripheral side, and is provided in the partition wall with the cooling passage in the second row communicating with the main gas passage by a plurality of film cooling holes through the airfoil surface with a plurality of the blade surface by passage with cooling passages in communication with the same second row in the cooling passage of the first column for cooling the Thus, the outer surface of the blade is film-cooled, and a cooling turbine blade for cooling a gas turbine is provided in which the cooling passage in the second row communicates with the cavity on the inner peripheral side and serves as a supply passage for seal air.
[0013]
That is, according to the present invention, since the sealing air supplied from the outer peripheral side of the stationary blade is selected in the cooling passage of the second row, the heat load is low and the heat exchange amount of the sealing air is small. The proper temperature can be maintained.
[0014]
In addition, a part of the sealing air of the second row cooling passage is divided into the first row cooling passage and flows through the plurality of communication holes, and this air flows from the sealing air to the first row cooling passage. The cooling air is used to cool the blade surface, and the blade front end corresponding to the cooling passage in the first row is cooled and then flows out through a plurality of film cooling holes to cool the film on the outer surface of the blade. Even without increasing the number of parts such as, it is possible to secure suitable sealing air to the inner peripheral cavity and maintain proper cooling of the blade front end.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
Note that the same parts as those of the above-described conventional one are denoted by the same reference numerals in the drawings, and redundant description will be omitted as much as possible, and points unique to the present embodiment will be mainly described.
[0018]
In the present embodiment, the sealing air 3 that also serves as blade cooling in the second example of the prior art is not the first row cooling passage A provided at the blade leading edge but the heat load that is lower. It is introduced into the second row cooling passage B, the second row cooling passage B is cooled and a part thereof is divided and supplied to the first row cooling passage A, and the remaining portion is introduced into the inner cavity 10 as seal air. To do.
[0019]
That is, as clearly shown in FIGS. 1 and 2, a plurality of communication holes 6 are formed in the cooling passage wall 11 separating the first row cooling passage A and the second row cooling passage B provided at the blade leading edge. In addition, a plurality of film cooling holes 7 are also provided on the back side and the abdomen side of the wing portion 5 of the first row cooling passage A.
[0020]
Further, the inner shroud 8 and the outer shroud 9 of the first row cooling passage A are closed, and the cooling passages after the third row (third row cooling passage C, fourth row cooling). The cooling passage D and the fifth row cooling passage E) have the same structure as the conventional one.
[0021]
In the present embodiment configured as described above, after the cooling medium 1 having both the sealing function and the blade cooling function is supplied from the outer shroud 9 side to the second row cooling passage B, the blade surface in the passage is cooled, A part of the cooling medium 1 is introduced into the inner cavity 10 as sealing air 3.
[0022]
The rest is supplied to the first row cooling passage A through the communication hole 6, and after cooling the blade surface as cooling air, it is ejected from the film cooling hole 7 into the mainstream high-temperature gas to cool the blade outer surface. .
[0023]
Note that the cooling medium 2 supplied to the third row cooling passage C is the fourth row cooling passage D, the fifth row cooling passage E and the blades sequentially bent as a serpentine as cooling air in the same manner as the conventional one. After cooling the surface, it is ejected from the trailing edge into the mainstream hot gas.
[0024]
In this way, according to the present embodiment, the seal air is supplied to the second row cooling passage B at the leading edge where the heat load is low, and a part of the sealing air passes through the communication hole 6 of the cooling passage wall 11 to be the first. In order to provide film cooling on the outer surface of the rear blades supplied to the row cooling passage A, the blade surface corresponding to the second row cooling passage B receiving the film cooling drops in temperature, and the heat of the second row cooling passage B Since the load is further reduced, the temperature rise of the sealing air here can be more reliably suppressed.
[0025]
Thereby, since the temperature rise of the seal air supplied to the inner cavity 10 through the second row cooling passage B is sufficiently suppressed, it is not necessary to use a seal tube, and the increase in the number of parts and the number of processing steps can be suppressed.
[0026]
When adjusting the ratio between the flow rate supplied to the inner cavity 10 as seal air in the second row cooling passage B and the flow rate supplied to the first row cooling passage A side, the cooling passage outlet on the inner cavity 10 side is adjusted. A diaphragm may be provided.
[0027]
In the present embodiment, the seal air 3 is supplied to the inner cavity 10 via the second row cooling passage B. However, the supply of the seal air 3 is supplied to the second row cooling passage B. The second row cooling passage B and the third row cooling passage C after the second row cooling passage B may be selected.
[0028]
When such a change is made, the passage after the third row cooling passage C has a smaller thermal load than the second row cooling passage B, so that the sealing air maintains a more suitable low temperature. Sealing air suitable for the inner cavity 10 can be secured.
[0029]
Although the present invention has been described with reference to the illustrated embodiment, the present invention is not limited to this embodiment, and it goes without saying that various modifications may be made to the specific structure within the scope of the present invention. Absent.
[0030]
【The invention's effect】
As described above, according to the present invention, a plurality of cooling passages extending in the radial direction are formed inside the stationary blade, and a part of the cooling passages serves as a sealing air supply passage for supplying sealing air from the outer peripheral side of the stationary blade to the cavity on the inner peripheral side. In the gas turbine cooling vane, the cooling passage in the first row from the upstream side is covered by both the inner peripheral side and the outer peripheral side, and the same is provided by a plurality of communication holes provided in the partition wall with the cooling passage in the second row. the wing skin surface film cooling communicates with the main gas passage by a plurality of film cooling holes through the airfoil surfaces together with cooling passages in communication with the second column to cool the blade surface in the cooling passages of the first column the second column of the cooling passage communicates with the inner periphery of the cavity constitutes the gas turbine cooling stationary blade as a supply passage for sealing air Tei Runode, sealing air supplied from the stationary blade outer peripheral side, the heat load 2nd row with low heat exchange amount of seal air By being selected却通path, it is possible to maintain the appropriate temperature as sealing air, also, the cooling passage of the first row, a part of the sealing air in the second row of cooling passages is known more flows through the communication hole, the air is changed to cool air to cool the blade surface in the cooling passages in the first row from the sealing air, a plurality cools the blade front end portion corresponding to the cooling passage of the first row The film flows out through the film cooling holes and cools the film on the outer surface of the blade , thereby ensuring the cooling function of the cooling passage in the first row and further reducing the thermal load of the cooling passage in the second row. It was possible to obtain a gas turbine cooling stationary blade that secures suitable sealing air to the inner cavity and maintains proper cooling of the blade front end without increasing the number of parts such as seal tubes. It is.
[Brief description of the drawings]
FIG. 1 is a perspective sectional view showing an outline of a gas turbine cooling stationary blade according to an embodiment of the present invention.
2 shows a schematic cross section of the gas turbine cooling stationary blade of FIG. 1, wherein (a) is a longitudinal sectional view, and (b) is a II-II sectional view of (a).
FIG. 3 shows a schematic cross section of an example of a conventional gas turbine cooling stationary blade, wherein (a) is a longitudinal sectional view and (b) is a sectional view taken along line III-III of (a).
4A and 4B are schematic cross-sectional views of another example of a conventional gas turbine cooled stationary blade, wherein FIG. 4A is a vertical cross-sectional view, and FIG. 4B is a cross-sectional view taken along line IV-IV in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cooling medium 2 Cooling medium 3 Sealing air 4 Sealing tube 5 Wing | blade part 6 Communication hole 7 Film cooling hole 8 Inner shroud 9 Outer shroud 10 Inner cavity 11 Cooling passage wall A 1st row cooling passage B 2nd row cooling passage C 3rd row cooling passage D 4th row cooling passage E 5th row cooling passage

Claims (1)

In the gas turbine cooling stationary blade, a plurality of cooling passages extending in the radial direction are formed inside the stationary blade, and a part of the cooling passage is used as a sealing air supply passage for supplying sealing air from the stationary blade outer peripheral side to the inner peripheral cavity. The cooling passage of the first row from the upstream side covers both the inner peripheral side and the outer peripheral side, and a plurality of communication holes provided in the partition wall with the cooling passage of the second row The blade surface is cooled by the cooling passage in the first row in the same manner, and the outer surface of the blade is cooled by the plurality of film cooling holes penetrating the blade surface to the mainstream gas passage to cool the second row. A gas turbine cooling stationary blade characterized in that a passage is communicated with a cavity on an inner peripheral side to serve as a supply passage for sealing air.

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