JPS60204904A - Gas turbine blade - Google Patents

Abstract

PURPOSE:To uniformaize cooling by respectively providing a first cooling fluid passage in a blade around the surface thereof and a second cooling fluid passage inside the blade. CONSTITUTION:A first cooling fluid passage 10 is provided between a parent material 2 of a blade 1 and a surface member 3, which is communicated with cooling water supply piping 13 and plenums 5, 6. In addition, a second cooling fluid passage 9 is provided inside the blade 1, which is communicated with cooling water supply piping 14, plenums 7, 8, and a cooling water waste pipe 15. Thus, cooling air passage through the first cooling fluid passage 10 is prevented from being raised in temperature whereby the surface of the blade 1 exposed to hot temperature can be uniformly cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to blades of gas turbines, and particularly to stationary blades of gas turbines used for power generation and 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 refrigerant passages all inside the wing.

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, and Since sufficient cooling performance cannot be obtained by cooling the wings alone, we have no choice but to rely on a film cooling method, which blows cooling air out of the wings through small holes or slits formed in the wings. 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 Gaster Pino and a decrease in thermal efficiency.

In addition, in liquid-cooled blades, the heat transfer coefficient within the refrigerant passage is high, so the back surface temperature is determined based on the temperature and heat transfer coefficient distribution on the gas side and the thermal resistance of the blade to the refrigerant passage, which is determined by the internal structure of the blade. The degree to which it is determined increases. Therefore, the cooling structure inside the blade is greatly affected by the thermal conditions directly outside, making it extremely difficult to determine a reliable cooling structure inside the blade. This results in a significant lack of versatility with respect to changes in Furthermore, using a high-density liquid as a refrigerant means that the inside of the refrigerant passage inside the rotating blade becomes extremely high pressure due to high centrifugal force, and an internal blade structure is required to cope with this.

Generally, in order to deal with the high pressure mentioned above, the refrigerant passages are made into a small circular cross section and are arranged at predetermined intervals inside the blades. A strong three-dimensional temperature field is formed, 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 an object of the present invention is to obtain a gas turbine blade that can be cooled well and uniformly, and in which the generation of thermal stress is minimized.

[Summary of the invention]

In the present invention, a first cooling fluid flow path for passing cooling fluid through the blade near the blade surface that is in direct contact with high temperature gas is also provided.
By providing second cooling fluid passages inside each wing, utilizing heat exchange between the cooling fluids passing through both, and discharging part or all of the first cooling fluid to the outside of the wing structure. , has achieved the above objectives.

〔Effect of the invention〕

According to the present invention, by heat exchange of the eleventh second cooling fluid,
In particular, since the temperature rise of the first cooling fluid can be prevented, the outer surface of the blade, which is exposed to high temperatures, can be cooled more uniformly, the amount of air blown into the high-temperature gas can be significantly reduced, and the output and thermal efficiency can be increased. The wing body, which the high-temperature combustion gas directly collides with, does not have cooling air blow-off holes, so even if bad fuel is used, the cooling performance is unlikely to deteriorate.

In other words, in the gas turbine blade of the present invention, the amount of cooling air used to cool the blade surface is reduced by cooling it inside the blade using cooling water, and the temperature rise of the cooling air is suppressed to achieve homogeneous and efficient cooling. Good cooling can be achieved. Furthermore, if the air used for cooling the blades does not have to be recovered and is blown out and cooled at the blade roots, the internal piping required for water cooling can be omitted and the structure can be simplified. Even if this method is used, the temperature rise of the cooling air can be suppressed, and since the area targeted for film cooling is small, the amount of cooling air can be significantly reduced compared to conventional air-cooled blades, which provide peace of mind. The generated heat can be used to preheat fuel, water, and air, contributing to improving the efficiency of power plants.

[Embodiments of the invention]

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

A surface material 3 is protruded onto the surface of the base material, for example, on the circumferential surface of the structural base material 2, which has a top portion 2a, a wing plate 2b, and a root portion 2Cr, and whose cross section along the x-X line in FIG. It consists of pasting through multiple pinches.

FIG. 2 shows a sectional view <x-x> of an example in which the present invention is applied and the blade top and blade root are cooled by blowing cooling air. Wing top 2
a, g The root portion 2cK has a first cooling fluid supply plenum 5°, a blowout plenum 6, a second cooling fluid supply plenum 7, and a recovery plenum 8 formed therein, and the plenums 7 and 8 have a plurality of second cooling They are connected by a flow path 9. Note that the space (first cooling channel) formed between the surface member 3 and the base material 2 is connected from the 10ti plenum 5 to the plenum 6, and the supplied fluid is emitted from the blow-off hole 11 into the gas trap and cooled to a low temperature. By forming an air film on the outer surface of the blade, the temperature of the components is prevented.

In FIG. 2, the blade top part 2a has a configuration in which the supply plenum 5 and the discharge plenum 6 are connected by a flow path 12 to form a throttle structure for adjusting the flow rate, and the blade root part 2c has a configuration in which the first cooling flow path 10 is directly connected to the plenum 6. However, the configuration is not limited to this, and both the blade top and blade root portions can have a configuration similar to these. In addition, plenum 51CH
The air supply pipe 13 is connected to the plenum 7, and the cooling water supply pipe 14 is connected to the plenum 7.
A cooling water discharge pipe 15 is connected to the plenum 8 .

In the turbine stator blade described above, the surface member 3 can be attached by welding or diffusion bonding, and the member is particularly resistant to high temperature corrosion. The second cooling channel can be formed by embedding a tube made of a material that is resistant to water erosion and corrosion, or by forming small holes in the base material by electrolytic processing and joining the tubes between the plenums. can. The cooling air outlet hole is manufactured using pore forming technology such as 1dt processing or laser processing.

The cooling water supplied from the cooling water supply pipe 14 passes through the cooling path 9 from the plenum 7, is collected in the plenum 8, and is discharged from the discharge pipe 15.
Through this, I can get pregnant with Tsubasa Yui. The temperature of the cooling water is raised by heat transfer inside the blade body, so the heat is recovered externally.
Measure efficiency gains. On the other hand, air supplied from the air supply pipe 13 enters the plenum 5 and is divided into the plenum 6 and a flow path 10 directly below the surface material 3 when film cooling the top of the sardine. The blade top cooling air passes through the flow path and is blown out from the plenum 6 to the outside of the blade through the small holes 11. In addition, the airfoil cooling air passes through the flow path 1O) and is collected in the root blemish 5, and is passed through the small hole 11.
is ejected from the wing.

With this configuration, the cooling water supply plenum 7 only serves the role of dividing the cooling water, and the blade root can be effectively cooled with a small amount by using the air after cooling the blade surface. can. Furthermore, there is no need to form cooling water piping at the blade root or blade root top, and there is no need for a recovery pipe for cooling air from the blade root, so the structure is simple and manufacturing is easy.

The present invention is not limited to the above-mentioned embodiments, and the region to be film-cooled may be limited to the blade top or the blade root.

FIG. 3 shows the KY cross section of FIG. 1, and FIG. 4 shows a configuration in which the present invention further includes blowing out part of the cooling air to the trailing edge of the blade. The wing body configuration has changed at the trailing edge of the wing,
It has a trailing edge blowout hole 16 and a passage spacer 17, and is configured to blow out a portion of the cooling air to the rear of the blade. Of course, the wing member 2b may have a wing configuration with a scattered rear end, and
A configuration may also be adopted in which a bin fin or a turbulence promoter is attached to the inner surface of the flow path at the rear end of the blade.

[Brief explanation of the drawing]

Fig. m1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a sectional view showing the x-x cross section of Fig. 1, and Fig. 3 is a sectional view showing the Y-Y cross section of Fig. 1). Figure 8g4 is a sectional view showing a Y-Y cross section of another embodiment of the present invention. 1... Turbine' stationary blade 2... Structural base material 3... Surface member 4... Pin 5, 6.7.8. ...Plenum 9...Cooling pipe 10 Cooling channel 11...Air outlet hole 13...Air supply pipe 14...
...Cooling water supply pipe 15...Cooling water discharge pipe Fig. 1 Fig. 2 J17 Fig. 9 7

Claims (3)

[Claims] (1) A flow path space for a first cooling fluid is provided between a base material having a blade top, a blade plate, and a blade root, and a surface provided to cover the circumferential surface of the blade of this base material. Constituent surface members;
means for supplying a first cooling fluid to the space, and a part of the first cooling fluid is injected into a part or all of the searoud part connected to the blade top, the platform part connected to the blade root, and the outer surface of the blade body. A hole structure or slit-like structure that discharges all of the fluid to the outside of the blade structure, a large number of cooling pipes provided near the periphery of the blade plate of the component material, and a second cooling fluid that is supplied to and discharged from these cooling pipes. A gas turbine blade characterized in that it has a means for. (2) The gas turbine blade according to claim 1, characterized in that the first cooling channel has a lip structure that faces the fluid flow. (3) The gas turbine blade according to claim 1, characterized in that the first cooling channel has a fin structure parallel to the fluid flow.