JPS5918205A - Moving blade of gas turbine - Google Patents

Abstract

PURPOSE:To cool efficiently and uniformly each part of a moving blade main body by a method wherein a throttle structure uniforming the rate of flow of a cooling fluid from plural small holes by local throttling of the cross-section area of each flow channel is arranged in plural cooling fluid flow channels provided inside of the moving blade main body. CONSTITUTION:A moving blade is provided with a blade main body 1, a blade base part 2 for fixing said moving blade to a rotating shaft and a cooling structure 3 provided inside of said components. The cooling structure 3 is formed of cooling fluid introducing passage 11 and plural cooling lines 12-14 respectively communicated with said passage 11. In this case, each ring shape projected walls 20, 27, 33 are protruded in plural number along the height direction on the inner surface of the walls forming each passage 17, 24, 29 in each cooling line 12-14. Thus, a structure which locally throttles the cross section area of each passage 17, 24, 29 is formed. Then the pressure increase caused by the centrifugal force is restrained by a flow control function obtained from each throttling structure. Thereby, each part pressure of each passage 17, 24, 29 is made approx. uniform, and the cooling fluid quantity flowed from each small hole 18, 25, 30, 31 is also uniformed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a rotor blade for a turbine, and more particularly to an improvement in a rotor blade equipped with a fluid cooling structure.

[Background technology of the invention]

In general, a turbine has many advantages over a reciprocating engine, such as being smaller and lighter and being able to provide greater horsepower. Such gas turbines typically have a compressor and seven shafts on one shaft.
The pressure inside the combustor is increased using high-pressure air compressed by a compressor, and in this state, fuel is injected into the combustor and combusted, and the high-temperature, high-pressure gas generated by this combustion is to be expanded using a four-power turbine.
It is configured to obtain rotational power. The compressor is
Normally, the blade temperature will increase due to the guide vane, rotor vane, and combustion gas.

Current heat-resistant metals that make up blades cannot be operated for long periods of time at temperatures exceeding 900°C. Therefore, in order to extend the operational life of the blade, there is no choice but to lower the X temperature by some means.

[Problems with background technology]

For the reasons mentioned above, various types of turbine blades equipped with cooling structures have been proposed. Wings equipped with these cooling structures usually have a cooling fluid passage provided in the blade body along the height direction of the blade body, and the cooling fluid guided into the passage passes through a wall that constitutes the passage. , and a plurality of small holes are provided in the height direction of the wing body to allow the air to flow out into the air. Namely.

The blades have a convection cooling effect that occurs when the cooling fluid flows through the passages, and each small hole has a centrifugal force acting on the cooling fluid that exists in the passages provided in the blades. .

As a result, the pressure within the passage is lowest in the part located on the root side of the blade body and highest in the part located in the tip part (TIG part) of the tool body.

For this reason, the distribution of the amount of cooling fluid flowing out from each of the plurality of small holes, which are provided through the wall constituting the passage and extending in the height direction of the blade body, becomes uneven in the height direction of the tool body. , uneven cooling inevitably occurs. Therefore, in conventional blades, a method is adopted in which the amount of cooling fluid is increased in order to prevent the above-mentioned uneven cooling from occurring. However, when the amount of cooling fluid is increased in this way, aerodynamic loss also increases in accordance with the increased pressure, which causes a problem in that efficiency cannot be improved.

[Purpose of the invention]

The present invention has been made in view of the above circumstances [Summary of the Invention] A gas turbine rotor blade according to the present invention has a cooling fluid passage provided in the rotor blade body along the height direction of the rotor blade body. To,
By locally narrowing the flow cross-sectional area of the above passage, each of the above-mentioned /j
- A feature is that a plurality of throttling mechanisms are provided along the passage to equalize the amount of cooling fluid flowing out from the holes.

〔Effect of the invention〕

With the above configuration, the flow resistance of the portion where the fD mechanism is located can be adjusted by the aperture mechanism. Therefore, by setting the flow cross-sectional area of the throttling mechanism to a predetermined value in advance, it is possible to prevent a large pressure difference from occurring in the cooling fluid passage due to centrifugal force, and as a result, the height of the blade body can be reduced. It is a longitudinal cross-sectional view taken along the damping line and showing that the amount of cooling fluid flowing out from each of the plurality of small holes provided in the direction is made almost uniform.

This moving blade can be roughly divided into a blade body 1 and a blade body 1.
The cooling mechanism 3 is composed of a blade root 2 for fixing to a rotating shaft (not shown), and a cooling mechanism 3 provided within the blade root 2 and within the blade body 1. Cooling fluid introduction passages 11 formed in the height direction of the blade, and first... Second.
It is composed of a third cooling system 12.13°14.

As shown in FIG. The second cooling system 13 is provided with a plurality of cooling fluids provided in the wall 15 in the height direction, and the cooling fluid guided into the passage 17 is connected to the partition walls 21 and 2.
2 extends in the height direction of the blade body 1, and at the tip of the blade body 1, the direction is changed by 180° to the leading edge side opening by the partition walls 22 and 23 and K, and extends to the root of the blade body 1. Furthermore, at the root portion, a bending passage 24 whose direction is changed by 180° to the leading edge side mouth by partition walls 23 and 16 and extending to the tip of the wing body 1, and partition walls 21 and 22 of this bending passage 24 are formed. The part where is located and the partition walls 23 and 16
The wall located on the ventral side of the wing body 1 at the part where the
As shown in the figure, a plurality of small holes 25 for film cooling are provided through the blade body 1 in the height direction, and a wall forming the bending passage 24 and on the ventral and dorsal sides of the blade body 1. The lip 26 protrudes from the inner surface of the wall 26 to increase the heat transfer effect, and the wall constituting the bending passage 24 includes an annular protruding wall 27.
It is made up of.

As shown in FIG. 2, a plurality of small holes J for film cooling (7 and A plurality of small holes 3) are formed in the trailing edge wall 28 in the height direction and are guided into the passage 29 to allow the cooling fluid f to flow out of the blade, and the inner surface of the wall constituting the passage 29 is formed on the ventral side of the blade body 1 and A plurality of ribs 32 are provided on the dorsal side to increase the heat transfer effect, and a plurality of ribs 32 are provided on the inner surface of the wall constituting the passageway 29 in the height direction to increase the flow cross-sectional area of the passageway 29. It is composed of an annular projecting wall 33 that narrows locally.

With the above configuration, the cooling fluid introduced into the cooling fluid introduction path 1 is divided into three parts at the root part within the blade body 1, as shown by the thick arrows in the figure, and the cooling fluid is divided into three parts at the root part within the blade body 1. Second. It flows into a third cooling system 12.13°14.

Finally, it is ejected from the small holes 18 and cools the leading edge of the blade body 1. Further, while the cooling fluid that has flowed into the second cooling system 13 flows through the bent passage 24, it finally jets out from the small hole 25 and cools the ventral side outer surface of the trailing edge of the intermediate axle 1 of the blade body 1. It is ejected from the small hole 31 to cool the trailing edge.

In this case, an annular projecting wall 20, 27, 33 is provided on the inner surface of the portion of the passage of each cooling system 12, 13, 14 extending in the height direction of the blade body 1 to locally narrow the entire flow cross-sectional area of the passage. Since a plurality of are provided in the height direction, each annular protruding wall 20
．． By setting the inner diameter of 21.33 to a predetermined height direction, each annular protruding wall 20.27.33 can exhibit a flow control function, and this flow control function suppresses pressure increase due to centrifugal force. I can do it. Therefore, since the power applied to each part of each passage can be made almost uniform, the amount of cooling fluid flowing out from each of the small holes 1B, 25° 30, and Jjl can be made uniform over the cylindrical direction. For this reason.

This is a cross-sectional view of each part of the blade main body 1 taken along the entry line A--in FIG. 1 and viewed in the direction of the arrow in FIG.

1... Wing body, 2... Wing root, 17.24.29.
... Passage, 18.25.30.31 ... Small hole, 20°27.33 ... Annular projecting wall.

Applicant: Director of the Agency of Industrial Science and Technology Makoto Ishizaka - Figure 1

Claims (1)

[Claims] A cooling fluid passage is provided in the rotor blade body along the height direction of the blade body, and the cooling fluid guided to the passage passes through a wall forming the passage.