JPH04109401U - air cooled rotor blades - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an air-cooled rotor blade that can prevent shavings generated by sliding the rotor blade against the inner wall surface of a turbine case from clogging the cooling air outlet. [Structure] An air-cooled rotor blade in which a counterbore portion 3 is formed from near the periphery of the cooling air blow-off hole 2 provided on the upper surface portion 1 of the rotor blade to the rear edge of the rotor blade. [Effects] Shavings generated when the rotor blades slide against the inner wall surface of the turbine case can be prevented from clogging the air outlet on the upper surface of the rotor blades, and the turbine can move without pressure loss, ensuring that the turbine always operates normally. , and can operate efficiently.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This idea is based on an air-cooled engine with a unique shape in the top surface attached to the turbine disk. It's about wings.

0002

[Conventional technology]

As is well known, the air-cooled rotor blades of a gas turbine operate at maximum capacity when the gas turbine rotates at full speed. It has the maximum heat resistance so that it can withstand the hot atmosphere temperature when it exerts its strength. It is manufactured in parallel. Therefore, the air-cooled rotor blades need to be constantly cooled. There is a point. For such an air-cooled rotor blade, the cooling air set by the cooling calculation Air passages, in other words, air passages provided at the bottom of the air-cooled rotor blades, which carry the cooling air that is pumped from the compressor. This cooling air is introduced from the inflow hole and then passed through the blowout hole and the blowout hole provided at the edge of the downstream surface of the blade. One system of heat exchange air passages blowing out from the blow-off holes provided on the upper surface of the wing or under the wing. Two systems of heat are blown out from the blow-off holes on the edge of the flow surface and the blow-off holes on the upper surface of the blade. Gas turbine blades having replacement air passages are known.

0003 The air-cooled rotor blades have their upper surfaces facing the inner wall surface of the turbine casing. Provide a clearance (gap) so that it does not come into contact with the inner wall surface of the casing. - Attached to the bin disk. However, this clearance A technical issue is that the turbine cannot operate efficiently due to pressure loss during rotation. It had

0004 Therefore, in order to reduce the clearance as much as possible, the upper surface of the air-cooled rotor blade and the Progress is being made in the development of technology that will improve the sliding contact between the inner wall surface of the housing and the inner wall surface of the housing. However, in this attempt, the air-cooled rotor blades sliding on the inner wall surface of the casing were The rear edge of the blowout hole provided on the top surface scrapes the inner wall surface of the casing, and this scraping remains on the top. This deposit accumulates in the cooling air outlet, and furthermore, this deposit is exposed to the high ambient temperature. As a result, the cooling air passage becomes clogged, and the operation In addition to having a negative impact on the cooling of the blade, if the above welded material breaks off, it may cause other This can result in the rotor blades colliding with the rotor blades, resulting in pierce or damage. A new challenge arose, which negatively affected the operation of the bin.

[0005] Therefore, as shown in FIG. 3(A), the upper surface of the air-cooled rotor blade rotates in the direction of the arrow. A wall 4 is formed around the edge of 1, and the shavings are deposited in the cooling air outlet 2. An air-cooled rotor blade has been proposed that can prevent this. As is clear from FIG. 3(B), which shows a partial cross section of the Y-Y section in FIG. 3(A), this The wall 4 is formed higher than the upper surface part 1 of the air-cooled rotor blade, and rotates in the direction of the arrow. When the front edge of the rear wall of the rotor blade of the turbine slides on the inner wall surface 5 of the casing, Even if the resulting shavings 6 accumulate on the front part of the rear wall, after this There is a distance between the front wall and the cooling air outlet 2, and there is a distance between the rear wall 4 and the top of the air-cooled rotor blade. Since there is a height between the position of the surface part 1 and the position of the surface part 1, it is necessary to close the cooling air outlet 2. First, clogging due to shavings 6 can be prevented. However, if it is a large air-cooled rotor blade, it is possible to form such a wall 4. However, for small air-cooled rotor blades that do not have sufficient blade thickness, forming the wall 4 is difficult and impractical. The current situation is that it has not been put to use.

[0006] On the other hand, as shown in FIG. 4(A), the upper surface portion 1 of the air-cooled rotor blade rotates in the direction of the arrow. A counterbore portion 3 is formed near the periphery of the cooling air blow-off hole 2 provided in the An air-cooled rotor blade is proposed to prevent air from accumulating in the cooling air outlet 2 and clogging it. It is being proposed. As is clear from FIG. 4(B), which shows a partial cross section of the Z-Z section in FIG. 4(A), this The counterbore portion 3 is formed lower than the upper surface portion 1 of the air-cooled rotor blade, and is formed to provide cooling air. Since the air blowing hole 2 is provided in this counterbore 3, the turbine rotating in the direction of the arrow When the rear edge of the counterbore portion 3 of the rotor blade slides on the casing inner wall surface 5, The resulting shavings 6 are deposited on the front of the rear edge of the counterbore 3 to prevent clogging. The aim is to prevent this from happening. However, if it is a small air-cooled rotor blade, the rear edge of this counterbore 3 and the cooling Since it is difficult to maintain a sufficient distance from the air outlet 2, and the counterbore 3 cannot be formed deep, With this counterbore shape, the cooling air outlet 2 is cut from the back of the counterbore 3. The debris 6 accumulates and eventually clogs the cooling air outlet 2. become. In this way, the seat is placed near the periphery of the cooling air outlet 2 provided on the upper surface 1 of the air-cooled rotor blade. Forming the hollow portion 3 can sufficiently prevent the accumulation of the shavings 6. Therefore, it is difficult to apply this technology to small moving blades, regardless of whether they are large or small. There was a demand for the development of an air-cooled rotor blade that could solve the problem.

[0007]

[Problem that the idea aims to solve]

This idea solves the above technical problems and allows the air-cooled rotor blades to slide on the inner wall of the casing. This prevents shavings from accumulating in the cooling air outlet and clogging it. The purpose is to provide air-cooled rotor blades.

[0008]

[Means to solve the problem]

In order to solve the above-mentioned technical problem, this idea was developed to create a wing equipped with cooling air blow-off holes. Attach the top surface to the turbine disk by sliding the top surface against the inner wall surface of the gas turbine casing. In the air-cooled rotor blade that has been installed, from the vicinity of the cooling air outlet to the trailing edge of the rotor blade. It crosses over to form a counterbore.

[0009]

[Effect]

According to this idea, the area near the cooling air outlet provided on the top surface of the air-cooled rotor blade A specific counterbore is formed over the trailing edge of the rotor blade, so the rotating turbine The shavings generated by the sliding of the rotor blades on the inner wall surface of the casing are It has the effect of preventing the air from accumulating and welding in the cooling air outlet and clogging it. In addition, since the air-cooled rotor blades are not affected by shavings, it is necessary to remove them from the inner wall of the casing. It has the ability to slide on surfaces.

0010

【Example】 An embodiment of this invention will be described below with reference to the drawings. Figure 1 shows an air-cooled rotor blade with a counterbore of this invention, (A) is a top view, (B ) is an enlarged cross-sectional view of section XX in Fig. 1(A), and Fig. 2 shows the counterbore of this invention. A top view showing another example of an air-cooled rotor blade, FIG. 3 shows a conventional air-cooled rotor blade, (A) is a top view, (B) is a partial cross-sectional view, and Figure 4 shows a conventional air-cooled rotor blade with a counterbore. (A) is a top view, and (B) is a partial sectional view.

[0011] In Fig. 1(A), 1 is the upper surface of the air-cooled rotor blade, 2 is the cooling air outlet, and 3 is the seat. It is clear from FIG. 1(B), which shows the enlarged cross-section of section XX in FIG. 1(A). As shown in FIG. It is formed with approximately the same width from the vicinity of the periphery to the trailing edge of the rotor blade. In addition, the above location The hollow portion 3 is formed by electric discharge machining after manufacturing the air-cooled rotor blade. According to this idea, the air cooling device slides on the inner wall surface of the casing (not shown) in the direction of the arrow. Even if the front edge of the upper surface part 1 of the rotor blade scrapes the inner wall surface of the casing and scrapes are generated, it will not cool. The cooling air outlet 2 is a counterbore-shaped hole located lower than the upper surface 1 of the air-cooled rotor blade. Since the shavings are formed at a certain place, the shavings can pass over the front edge of the upper surface part 1 and reach the seat. Even if it enters the hollow part, it will be blown to the downstream side, and furthermore, it will be thrown into the upper surface part 1 of the air-cooled rotor blade. The counterbore portion 3 extends from the vicinity of the cooling air outlet 2 to the rear edge of the rotor blade. Since they are formed to have approximately the same width, the rear edge of the cooling air outlet 2 is located on the casing. There is no need to scrape the inner wall surface, and there is no place for the scrapes that are blown to the downstream side to accumulate. Since there is no such place, this accumulation can be prevented. The cooling air blow-off holes 2 are no longer clogged due to accumulation of shavings.

0012 FIG. 2 shows another embodiment of the air-cooled rotor blade in which a counterbore is formed according to this invention. In the example shown in FIG. 1(A), the area around the cooling air outlet 2 provided in the upper surface part 1 of the air-cooled rotor blade is From the vicinity to the trailing edge of the rotor blade, there is a wide area similar to the shape of the leading edge of the air-cooled rotor blade mentioned above. A counterbore portion 3 is formed. This air-cooled rotor blade is similar to the one in Figure 1 above, The cooling air blow-off holes 2 provided on the upper surface 1 of the air-cooled rotor blades prevent the accumulation of shavings. There was no clogging due to the accumulation of Note that the air-cooled rotor blades are made using a mold made in advance to form the above-mentioned counterbore shape. The above-mentioned counterbore portion 3 is formed using the same. In addition, in this design, the counterbore is a cooling air blower provided on the upper surface 1 of the air-cooled rotor blade. The turbine is formed from the vicinity of the exit hole 2 to the rear edge of the rotor blade, and rotates in the direction of the arrow. The shavings generated when the rotor blades of the bin slide on the inner wall surface of the casing are deposited. Any shape is acceptable as long as it does not interfere.

[0013]

【Effect of the invention】

According to this idea, the area near the cooling air outlet provided on the top surface of the air-cooled rotor blade Since a counterbore is formed across the rear edge of the rotor blade, the rotor blade of the rotating turbine is The shavings generated when the casing slides on the inner wall surface of the casing are This prevents the blowholes from being deposited, welded, and clogged, and ensures normal rotor blade cooling. At the same time, the detachment of the above-mentioned welds may cause various adverse effects on other air-cooled rotor blades. Since this eliminates the problem, the turbine can be operated normally at all times. In addition, the air-cooled rotor blades can slide on the inner wall surface of the casing without being affected by shavings. This allows the turbine to move efficiently without pressure loss, allowing the turbine to operate efficiently. It has a positive effect.

[Brief explanation of drawings]

FIG. 1 is a top view and a partial sectional view showing an air-cooled rotor blade of this invention.

FIG. 2 is a top view showing another embodiment of the air-cooled rotor blade of this invention.

FIG. 3 is a top view and a partial sectional view of a conventional air-cooled rotor blade.

FIG. 4 is a top view and a partial sectional view showing an air-cooled rotor blade provided with a conventional counterbore.

[Explanation of symbols]

1 Upper surface of air-cooled rotor blades 2 Cooling air outlet 3 Counterbore

Claims (1)

[Scope of utility model registration request] Claim 1: The upper surface of a wing provided with cooling air blow-off holes,
In an air-cooled rotor blade that is attached to a turbine disk in sliding contact with the inner wall surface of a casing of a gas turbine, a counterbore is formed from the vicinity of the periphery of the cooling air outlet to the rear edge of the rotor blade. Wings.