JPS6179803A - Static blade for gas turbine - Google Patents

Abstract

PURPOSE:To perform uniform and efficient cooling through a simple structure, by a method wherein the one cooling fluid flow passage is installed within a blade in the vicinity of a blade surface, and the other cooling fluid flow passage is installed to the interior of the blade, and heat exchange between cooling fluids passing through the two flow passages is utilized. CONSTITUTION:A static blade 1 has a blade top part 2a, a blade plate 2b, and a blade root part 2c, and a blade surface material 3 is mounted to the peripheral surface of a structural base material 2 through a pin structure 4. Plenum chambers 5 and 6 for feeding and recovering second cooling fluid are formed in the top part 2a, and are communicated with intermediate plenum chambers on the feed side 7 and the recovery side 8, formed in the root part 2c, through a passage 9. Feed and recovery plenum chambers 11 and 12 for feeding and recovering first cooling fluid, formed in the top part 2a, are communicated with intermediate plenum chambers 13 and 14, formed in the blade root part 2c, through a passage 15. Further, feed ports 17 and 19 and recovery holes 18 and 20 for first and second cooling fluids are formed in the blade top part 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a gas turbine, and particularly to a stationary blade of a gas turbine used for power generation or the like.

[Technical background of the invention and its problems]

As is well known, increasing the gas temperature at the inlet of the gas turbine is effective in improving the thermal efficiency of a power plant configured with a combined cycle of a gas turbine and a steam turbine. However, with the gas turbine blades currently in use made of heat-resistant alloys, the gas turbine inlet gas temperature is limited to 900°C.
If the temperature is higher than that, there is a risk that the heat-resistant alloy will reach its service limit temperature, and the reliability of the gas turbine will therefore be greatly reduced. For this reason, gas turbine blades with various fluid cooling structures have been studied.

Gas turbine blades with a fluid-cooled structure that have been considered in the past are broadly divided into air-cooled blades and liquid (mainly water)-cooled blades.
Both have a structure with multiple coolant passages inside the blade.

However, in air-cooled blades, the heat transfer coefficient of the cooling air in the refrigerant passage is low, so when the gas temperature at the gas turbine inlet exceeds 1100'C, the amount of cooling air required increases significantly. Since sufficient cooling performance cannot be obtained by cooling the airfoils alone, it is necessary to rely on film cooling, which blows cooling air out of the blades through small holes or slits formed in the blades.

The resulting increase in the amount of cooling air and the blowing of low-temperature air into the high-temperature gas both lead to a decrease in the output of the gas turbine and a decrease in thermal efficiency.

In liquid-cooled blades, the heat transfer coefficient in the coolant passage is high, so the blade surface temperature is determined based on the temperature and heat transfer coefficient distribution on the gas side and the thermal resistance of the blade up to the coolant passage, which is determined by the internal structure of the blade. is determined more often. Therefore, the cooling structure inside the blade is greatly affected by the thermal conditions outside the blade, making it extremely difficult to determine a reliable cooling structure inside the blade. This results in a significant lack of versatility in response to changes in conditions. Furthermore, using a high-density liquid as a refrigerant means that the inside of the refrigerant passage inside the blade during one rotation becomes extremely high pressure due to high centrifugal force, and a blade internal structure is required to cope with this.

Generally, in order to deal with the high pressure mentioned above, the refrigerant passages are configured to have a small circular cross section and are arranged at predetermined intervals inside the blade. A strong three-dimensional temperature field is formed in the air, which causes problems such as the blade surface not being cooled uniformly and strong thermal stress occurring inside the blade.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and it is possible to obtain a simple structure of a gas turbine that achieves good and uniform cooling, minimizes the occurrence of thermal stress, and consumes only a small amount of cooling fluid. The purpose is

[Summary of the invention]

In the present invention, a first cooling fluid passageway for passing cooling fluid through H near the blade surface and a second cooling fluid passageway are provided inside the blade, and heat exchange between the cooling fluid passing through both is provided. In particular, is it possible to suppress the temperature rise of the first cooling fluid and achieve even and good cooling? The above objective is achieved by a method of transferring cooling fluid between a plurality of blades.

〔Effect of the invention〕

(1) By transmitting and receiving cooling fluid between a plurality of curves in a two-fluid cooling type gas turbine stationary blade that has full corrosion holes on the blade surface and uniformly cools the blade, the amount of cooling fluid used as a whole can be reduced.

(2) The number of cooling fluid supply and discharge ports can be reduced, resulting in a simpler structure and lower manufacturing costs.

[Embodiments of the invention]

FIGS. 1 and 2 show an embodiment of the present invention.

The stationary blade 1 has a blade top portion 2a, a blade plate 2b, and a blade root portion 2c, and a blade surface material 3t? For example, it is configured by pasting through a large number of pin structures 4t formed on the surface of the blade base material 20,
It is formed into a block by connecting multiple pieces.

FIG. 2 is a cross-sectional view taken along line XX of an example of application of the present invention when two blades are integrally molded. Inside the blade top part 2a, a second cooling fluid supply and recovery plenum chamber 5.6 is formed between the blades, and a supply side 7 is formed in the blade root part 2C.
The first recovery side 8 is connected to the middle brenum chamber by a number of second cooling fluid passages 9. In the blade root portion 2c, the intermediate plenum 7°80 is continuous by a jumper line 1o, but this jumper line may be formed in the blade root portion.

A supply plenum 111 and a recovery plenum 12 are formed at the blade top 2a for the first cooling fluid flowing directly below the blade surface, and the blade root 2
Wing surface material 3 up to 13.14° of the intermediate plenum formed at C
The cooling fluid flows through the first cooling fluid passage 15 formed between the blade base material 20 and the blade base material 20 for cooling. The blade root 2CK is provided with a second cooling fluid jumper line 16, but there is no problem even if this jumper line is made inwardly at the blade root.A first cooling fluid supply port 17 is provided at the blade top. Recovery hole 18. A second cooling fluid supply port 19 and a recovery hole 20 are provided. In each intermediate plenum, there are 9 plates 21 that define the direction of flow. It may be provided. With this configuration, a simple cooling system is realized in which two stator blades are combined and the supply/recovery loop is reduced to 50%.

FIG. 3 shows another embodiment of the invention. With regard to the stator blade end wall, which is difficult to cool with this configuration, the first cooling fluid is collected in the plenum 11.23 in both the blowout hole 22, the blade top 2a, and the blade root 2C, which blows out in the form of a film. Cooling efficiency is increased by blowing out into the mainstream. According to this purchase, the first jumper line for cooling fluid at the blade root becomes unnecessary. Further, the supply plenum 11 may be configured to be internally divided from the blowing plenum.

FIG. 4 shows another embodiment of the present invention, in which the blade top end wall is cooled 24 by a second cooling fluid.

FIG. 5 shows another embodiment of the present invention, in which the first cooling fluid is exchanged between two blades through the jumper line 16 at the blade root 2C, and the second cooling fluid is supplied and recovered within each blade. be done.

6 and 7 are YY cross sections of the stationary blade shown in FIG. 1. FIG. 6 is an example in which the first cooling fluid is not blown out from the wing body.

FIG. 7 shows a case where a blowout hole 26 is provided in the trailing edge portion 25 of the blade to blow out the coolant.A dividing wall 27t may also be provided inside the blade to increase the velocity of the cooling fluid.

〔Effect of the invention〕

As is clear from the above, in the stator vane of the gas turbine of the present invention, the temperature rise of the first cooling fluid that cools the blade surface from directly below can be reduced by using the second cooling fluid, and the blade surface can be more uniform. Provides efficient cooling. In addition, since the first and second or first or second cooling fluid is exchanged between multiple blades, the amount of cooling fluid used can be reduced, and the cooling structure becomes very simple, which improves the efficiency of the power plant. This leads to a reduction in the cost of cooling blades.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of one embodiment of the present invention, FIG. 2 is a sectional view taken along line XX in FIG. 1, and FIGS. 3 to 5 are other embodiments of the present invention, The figure is a YX sectional view in FIG. 1 of the embodiment of the present invention. Turbine stationary blade, 2. Structural base material, 3... Blade surface material,
4 Pins, 5 to 8 Second cooling fluid plenum chamber;
9... Second cooling fluid passage, 10... Second cooling fluid blade root jumper line, 11-14... First cooling fluid plenum, 15 - First cooling fluid passage,
16. First cooling fluid blade root jumper line, 17
...first cooling fluid supply port, 18..first cooling fluid outlet, 19..second cooling fluid supply port, 20..second cooling fluid discharge port, 21..inside the plenum. Shikiri board, 2
2...First cooling fluid blowout hole, 23...Blenheim for blowing out, 24...Second cooling fluid end wall cooling hole. Agent Patent attorney Kensuke Norichika (and 1 other person) Figure 1 Figure 2 Figure 3 Figure 5 Figure 6 Figure 7

Claims (5)

[Claims] (1) A base material comprising a blade top, a blade plate, and a blade root, and a first cooling fluid flow path space provided between the base material and the peripheral surface of the blade, which is provided to cover the peripheral surface of the blade of the base material. a surface member constituting the space, a means for supplying and discharging a first cooling fluid into the space, a large number of cooling pipes provided near the periphery of the vane of the base material, and a second cooling fluid connected to these cooling pipes. In a stator blade block which is a collection of a plurality of stator blades of a gas turbine having means for supplying and discharging cooling fluid, the first and second cooling channels are respectively connected across the blade rows, and the first and second cooling channels are connected together over the blade rows. A gas turbine stationary blade that allows fluid to flow in opposite directions. (2) In the stationary blade block, the first cooling fluid is not transferred between the plurality of blades, but is blown out into the mainstream gas from the blade top, blade root, or part of the blade surface. The stationary blade of the gas turbine according to item 1. (3) A stator blade for a gas turbine according to claim 1, wherein the second cooling fluid is not transferred between a plurality of blades in the stator blade block, but is supplied and discharged from each blade. (4) The first cooling channel has a rib structure facing the fluid flow and a fin structure parallel to the fluid flow. gas turbine blades. (5) The gas turbine according to claims 1 to 4, characterized in that a hollow plenum chamber existing inside the blade top or blade root is partially partitioned to restrict the flow in one direction. wings.