JPH10252405A - Cooling moving blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cooling effect of an inversion part and the whole cooling passage by providing a plurality of flow guide pins in a row in a predetermined shape in the inversion part in a cooling moving blade which introduces cooling air into the cooling passage, inverts the direction of a stream of cooling air in the inversion part, and introduces cooling air into the next cooling passage. SOLUTION: Among four cooling passages formed inside a cooling moving blade for gas turbine 1 in the direction of blade length, an inlet side of the cooling passage 52B in a central part which is formed by extending in the direction of blade end part 60 is communicated with a cooling air introduction hole, is inverted in the direction of blade root part in an inversion part 3, and is communicated with the cooling passage 52C in a central part which is extended from the inversion part in the direction of blade root part. In this case, a flow guide pin 4 is provided like a semi-circular diffuser vane in which a passage on an outlet side is expanded and opened instead of conventional turning vane in the inversion part 3. Consequently, cooling air is guided by the flow guide pin 4, changes its direction downward, and collides against the flow guide pin 4 so that the disturbance of the stream is promoted and the heat transfer on a cooling face of the blade is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling blade used for a gas turbine or the like, which cools the inside of a blade with air.

[0002]

2. Description of the Related Art In a gas turbine, a cooling blade is used for cooling air to flow through the inside of the blade to cool the blade. FIG. 4 is a longitudinal sectional view of a cooling blade according to the serpentine method, and FIG. 5 is a sectional view of a cooling air passage.

In FIG. 4, reference numeral 1 denotes a cooling blade (hereinafter abbreviated as a blade), and four cooling passages are formed in two systems in the blade length direction. Among the cooling passages, the leading edge cooling passage 52A is provided close to the outer surface of the leading edge of the blade 1;
The cooling air introduction hole 54 provided on the leading edge side of the blade root 53 and the cooling air outlet 61 of the blade tip 60 communicate with each other.

[0004] 52B, 52C are central cooling passages,
The inlet side of the cooling passage 52 </ b> B communicates with a cooling air introduction hole 55 provided at the center of the blade root 53. The central cooling passage 52B is formed to extend in the direction of the blade tip 60 with the leading edge cooling passage 52A and a partition 63 therebetween. 52C. Central cooling passage 52C
Are formed to extend in the direction of the blade root portion 53 from the reversing portion 53 with the central cooling passage 52B and the partition 5 therebetween and with the trailing edge cooling passage 52D and the partition 64 described later.

[0005] Reference numeral 52D denotes a trailing edge cooling passage,
The blade root is extended in the blade length direction in proximity to the outer surface of the trailing edge, and the inlet side of the blade root communicates with the central cooling passage 52C and the blade root side reversing part 65, and the cooling air outlet 62 is connected to the blade tip part 60. Is open. Reference numeral 56 denotes a lightening hole formed in the blade root 53, and reference numeral 57 denotes a plug for closing the hole 56.

In each of the cooling passages 52A, 52B, 52C, and 52D at the front edge, the center, and the rear edge, as shown in a sectional view in FIG. ) 58 are formed at a predetermined pitch to increase the heat transfer area and turbulence the cooling air to increase the heat transfer coefficient.

As shown in FIG. 4, in this example, the turbulator 58 extends in the front edge cooling passage 52A in a direction perpendicular to the flow path, in the center cooling passage 52B in an obliquely upward leftward direction, and in the center cooling passage 52B. The cooling passage 52C extends obliquely upward and to the right, and extends radially at an inversion portion connecting the two passages 52B and 52C at the center, and further extends rearward.
In 2D, it is formed to extend obliquely upward and to the left.

FIG. 6 shows the central cooling passages 52B and 52B.
One conventional example of an inverting unit 3 for connecting C is shown.
In FIG. 6, reference numeral 59 denotes a turning vane, both ends of which are fixed to the passage walls 2a, 2b (see FIG. 5) of the reversing portion 3,
One is provided on the inlet side of the reversing unit 3 and two is provided on the outlet side. The outlet side passages are arranged in a semicircular diffuser vane shape in which the passage is expanded.

During operation of the gas turbine provided with the cooling blades, the cooling air of the first system is introduced into the blade through the cooling air introduction hole 54 of the blade root 53 as shown by the arrow Z1 in FIG. The leading edge of the blade 1 is cooled by flowing through the partial cooling passage 52A toward the blade tip 60, and flows out from the cooling air outlet 61 of the blade tip 60 as indicated by the arrow Z2 and is mixed with the main gas.

At this time, the cooling air flowing through the leading edge cooling passage 52A is turbulently formed by the turbulator 58 protruding from the passage blades 2a and 2b (see FIG. 5), thereby increasing the heat transfer coefficient. The formation of the turbulator 58 increases the transmission area, thereby increasing the cooling capacity.

Further, as shown by the arrow Z3 in FIG. 4, the cooling air of the second system is introduced into the blade through a cooling air introduction hole 55 formed in the center of the blade root 53, and the central cooling passage is formed. 52B flows in the direction of the wing tip 60 to cool the side near the leading edge at the center and enters the reversing part 3 on the wing tip side.

The cooling air entering the reversing portion 3 is guided by the turning vane 59 and changes its direction downward (toward the blade root), enters the other central cooling passage 53C, and removes the portion near the rear edge of the central portion. It flows toward the blade root 53 while cooling,
It turns upward at the blade root side reversing portion 65 and enters the trailing edge cooling passage 52D.

The cooling air entering the trailing edge cooling passage 52D cools the trailing edge of the blade 1 while flowing through the cooling passage 52D while receiving the effect of increasing the heat transfer coefficient by the turbulator 58. It joins the main gas stream from the air outlet 62.

[0014]

In the case where the cooling blade of the gas turbine adopts the serpentine cooling system shown in FIGS. 4 and 5, cooling by controlling the flow in the reversal portion 3 of the cooling passage. The challenge is to improve the effect of For example, when the turning vane 59 as shown in FIG. 6 is not provided, a vortex circulation flow is generated at the corner of the reversing portion 3,
In addition, the cooling performance is reduced due to the temporary low-speed flow.

Further, in the case where the turning vane 59 is provided as shown in FIG.
The pressure loss due to the friction between the air and the air flow increases dramatically,
It becomes impossible to flow the necessary amount of cooling air for cooling the blade 1. Further, if the air flow in the reversing section 3 cannot be controlled to obtain an optimal cooling effect due to the designed mounting position and the vane shape of the turning vane 59, the air flow is adjusted to the turning vane 59. There is also a problem that the cooling effect is inevitably reduced because there is no degree of freedom.

Accordingly, a first object of the present invention is to improve the heat transfer coefficient between the air flow and the cooling surface in the reversing portion and reduce the pressure loss of the air flow to reduce the reversal portion and the cooling passage as a whole. The object of the present invention is to obtain a cooling blade which can improve the cooling effect in the above. A second object of the present invention is to provide a cooling blade in which the selection of the mounting position and the shape of the guide member in the reversing portion has less influence on the cooling effect in the cooling passage and prevents the cooling effect from lowering.

[0017]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The gist of the present invention is to provide a plurality of cooling passages inside a blade along its longitudinal direction. Cooling blades configured to introduce cooling air from the root into the cooling passage, reverse the flow direction at a reversing portion in the middle of flowing the cooling passage, and introduce the cooling air into the next cooling passage. A plurality of flow guide pins are provided in a row in a predetermined shape at regular intervals to constitute a cooling air guide portion.

In the above means, the flow guide pin is optimally provided at the reversal portion on the blade tip side.

Further, in a preferred embodiment, the plurality of flow guide pins are arranged in a plurality of rows in a required shape on the reversing portion.

According to the above-mentioned means, when the cooling air flows in the cooling passage of the blade, the cooling air flow is guided by the row of the flow guide pins and is smoothly changed in the direction of the blade root to flow.

In such a flow, when the cooling air passes through the flow guide pin, it collides with the pin to promote turbulence, thereby increasing the heat transfer coefficient on the cooling surface of the blade, and High heat transfer performance can be maintained even when the air flow is low in the section, and the cooling effect can be improved in synergy with the action of increasing the heat transfer coefficient by the turbulator. As a result, the amount of cooling air can be reduced, and the performance of the gas turbine improves accordingly.

Further, according to the above-mentioned means, unlike the conventional turning vane, since there is a gap between the plurality of flow guide pins, the resistance of the air flow is reduced, the pressure loss is reduced, and the cooling air flow rate is reduced. Increase is possible.

Furthermore, even when the air flow in the reversing section is not controlled so as to follow the designed shape of the row of flow guide pins, the air flow can freely enter and exit from between the flow guide pins, so that cooling can be performed. No reduction in performance or increase in pressure loss occurs.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. 1 to 3 and FIGS. FIG.
Is a longitudinal sectional view (a sectional view in the blade length direction) of a cooling blade for a gas turbine to which the present invention is applied, and FIG. 5 is a sectional view of a cooling air passage. FIGS. 1, 2 and 3 are longitudinal sectional views showing the vicinity of the reversal portion of the cooling blade according to the first, second and third embodiments of the present invention, respectively.

In FIG. 4, reference numeral 1 denotes a cooling blade (hereinafter abbreviated as a blade), and four cooling passages are formed in two systems in the blade length direction. The leading edge cooling passage 52 </ b> A of the cooling passage is provided close to the outer surface of the leading edge of the blade 1, and the cooling air introduction hole 54 provided on the leading edge side of the blade root 53 and the cooling air of the blade tip 60. It is connected to the outlet 61.

52B and 52C are central cooling passages,
The inlet side of the cooling passage 52 </ b> B communicates with a cooling air introduction hole 55 provided at the center of the blade root 53. The central cooling passage 52B is formed to extend in the direction of the blade tip 60 with the leading edge cooling passage 52A and a partition 63 therebetween. 52C. Central cooling passage 52C
Are formed to extend in the direction of the blade root portion 53 from the reversing portion 53 with the central cooling passage 52B and the partition 5 therebetween and with the trailing edge cooling passage 52D and the partition 64 described later.

Reference numeral 52D denotes a trailing edge cooling passage,
The blade root is extended in the blade length direction in proximity to the outer surface of the trailing edge, and the inlet side of the blade root communicates with the central cooling passage 52C and the blade root side reversing part 65, and the cooling air outlet 62 is connected to the blade tip part 60. Is open. Reference numeral 56 denotes a lightening hole formed in the blade root 53, and reference numeral 57 denotes a plug for closing the hole 56.

In each of the cooling passages 52A, 52B, 52C, and 52D at the front edge, the center, and the rear edge, as shown in FIG. 5, a large number of turbulators 58 are provided on both wall surfaces of the passage at a predetermined pitch. As a result, the heat transfer area is increased and the cooling air is turbulent to increase the heat transfer coefficient. The above basic configuration is the same as the conventional one.

In the embodiment of the present invention, the reversing section 3 is provided with a flow guide pin instead of the conventional turning vane. That is, in the first, second and third embodiments of the present invention shown in FIGS. 1, 2 and 3, reference numeral 4 denotes a flow guide pin, both ends of which are passage walls 2a and 2b of the reversing portion 3, that is, FIG. The turbulator 58 shown in FIG. 5 is fixed to a passage wall where the turbulator 58 is provided, and is provided in a predetermined number.

In the first embodiment shown in FIG. 1, the flow guide pins 4 are arranged in a row on the inlet side of the reversing section 3 and in two rows on the outlet side. Are arranged in a row.

In the second embodiment shown in FIG. 2, the flow guide pins 4 are arranged in one row on the inlet side and two
The pins are arranged in a so-called "willow-like" manner so that the passage areas between the rows and the pin rows are substantially uniform.

In the third embodiment shown in FIG. 3, the flow guide pin 4 is closer to the inside of the reversing portion 3 (closer to the partition 5).
One row, two rows in series outside thereof, and a passage area between the pin rows are arranged in an arc shape across the partition 5 as a whole with a substantially uniform passage area.

The central cooling passages 52B, 52C and the reversing section 3 are provided with a number of turbulators 58 as shown in FIG. 4, but the turbulators are not shown in FIGS. ing.

During operation of the gas turbine equipped with the cooling blades configured as described above, the cooling air of the first system flows through the cooling air introduction hole 54 of the blade root 53 as shown by the arrow Z1 in FIG. And flows through the leading edge cooling passage 52A toward the blade tip 60 to cool the leading edge of the blade 1 and
The coolant flows out from the cooling air outlet 61 as indicated by the arrow Z2 and is mixed with the main gas.

At this time, the cooling air flowing through the leading edge cooling passage 52A is turbulently formed by the turbulator 58 protruding from the passage blades 2a and 2b (see FIG. 5), so that the heat transfer coefficient is increased. The formation of the turbulator 58 increases the transmission area, thereby increasing the cooling capacity.

Further, as shown by the arrow Z3 in FIG. 4, the cooling air of the second system is introduced into the blade through a cooling air introduction hole 55 formed in the center of the blade root 53, and a central cooling passage is formed. 52B flows in the direction of the wing tip 60 to cool the side near the leading edge at the center and enters the reversing part 3 on the wing tip side.

The cooling air entering the reversing section 3 is guided by the flow guide pins 4 in each row, and is guided downward (the blade root section 53).
To the other central cooling passage 5
2C, flows toward the blade root 53 while cooling a portion near the trailing edge of the center of the blade 1, turns upward at the blade root side reversing portion 65, and enters the trailing edge cooling passage 52D.

When the cooling air flows, in the reversing section 3, the flow guide pins 4 are formed as a set of a plurality of pieces along the flow path, as shown in FIG. 1, "diffuser vane shape", as shown in FIG. The cooling air flow is guided by the rows of the flow guide pins 4 and is directed in the direction of the blade root portion 53 because the cooling air flow is arranged in a required shape such as a "willow shape" and an "arc shape" as shown in FIG. You can change the direction smoothly and make it flow.

The cooling air is supplied to the flow guide pins 4.
When the air passes through the pin 4 and collides with the pin 4, the turbulence is promoted, whereby the cooling surfaces of the blades (passage walls 2a, 2b
Etc.), the high heat transfer performance can be maintained even when the air flow is low in the reversing section 3, and the cooling effect is synergistic with the increase in the heat transfer coefficient by the turbulator 58. Is improved. As a result, the amount of cooling air can be reduced, and the performance of the gas turbine improves accordingly.

In the blades according to the first to third embodiments, unlike the conventional turning vane 59, there is a gap between the plurality of flow guide pins 4, so that the conventional turning vane 59 is provided. The pressure loss is smaller than that of the wing.

Furthermore, even when the air flow in the reversing section 3 is not controlled so as to follow the designed shape of the row of the flow guide pins 4, the air flow can freely enter and exit from between the flow guide pins 4. In addition, there is no decrease in the cooling function of the air flow and no increase in pressure loss.

The cooling air that has turned upward at the blade root side reversing portion 65 and entered the trailing edge portion cooling passage 52D flows through the cooling passage 52D while increasing the heat transfer coefficient by the turbulator 58. While cooling, the trailing edge of the blade 1 is cooled and merges with the main gas flow from the cooling air outlet 62.

The flow guide pins 4 are shown in FIGS.
May be provided in the blade root side reversing portion 65 in the same arrangement as described above.

[0044]

The present invention is configured as described above.
According to the first to third aspects of the present invention, when the cooling air flows at the reversing portion, the cooling air collides with the flow guide pin when passing through the pin, thereby promoting the turbulence, whereby the blades The heat transfer coefficient on the cooling surface increases, and high heat transfer performance can be maintained even when the air flow is slow at the reversing portion. The cooling effect is improved in synergy with the heat transfer coefficient increasing action by the turbulator. realizable. As a result, the amount of cooling air can be reduced, and the performance of the gas turbine improves accordingly.

Further, according to the above-mentioned means, unlike the conventional turning vane, since there is a gap between the plurality of flow guide pins, the resistance of the air flow is reduced, the pressure loss is reduced, and the cooling air flow rate is reduced. The cooling effect can be increased, and the cooling effect can be improved from this aspect.

Furthermore, even when the air flow in the reversing section is not controlled so as to follow the designed shape of the row of flow guide pins, the air flow can freely enter and exit from between the flow guide pins, so that cooling can be performed. High cooling performance can be maintained without a decrease in performance or an increase in pressure loss.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of the vicinity of an inverted portion of a cooling bucket according to a first embodiment of the present invention.

FIG. 2 is an equivalent view of FIG. 1 showing a second embodiment of the present invention.

FIG. 3 is an equivalent view of FIG. 1 showing a third embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a cooling blade for a gas turbine.

FIG. 5 is a sectional view of a cooling air passage in the cooling blade.

FIG. 6 is an equivalent view of FIG. 1 showing a conventional cooling blade.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling moving blade 2a, 2b Passage wall 3 Inversion part 4 Flow guide pin 5, 63, 64 Partition 52A Front edge cooling passage 52B, 52C Central cooling passage 52D Trailing edge cooling passage 53 Blade root 54, 55 Cooling air introduction Hole 58 Turbulator 60 Blade tip 61, 62 Cooling air outlet

Claims (3)

[Claims] 1. A plurality of cooling passages are provided inside a blade along a longitudinal direction thereof, cooling air is introduced into the cooling passage from a blade root portion, and a flow direction is changed at a reversal portion in the middle of the cooling passage. In the cooling blade configured to be inverted and introduced into the next cooling passage, a plurality of flow guide pins are provided in a row in a predetermined shape at regular intervals in the inverted portion to guide cooling air. A cooling blade having a structure. 2. The cooling blade according to claim 1, wherein the flow guide pin is provided at a reversal portion on the blade tip side. 3. The cooling blade according to claim 1, wherein a plurality of rows of the plurality of flow guide pins are arranged in a required shape on the reversing portion.