JP2005069236A - Turbine cooling blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbine cooling blade capable of practicing favorable and efficient cooling even under a higher-temperature condition by improving a sealing performance between inserts and inner surfaces of a blade. <P>SOLUTION: The turbine cooling blade is equipped with a line of small holes 129 for cooling a plurality of films formed in the direction of a height of a hollow blade 172 on surfaces of the hollow blade 172 including cavities, a party wall 173 for partitioning the cavity into a front side and backside of the blade, and a plurality of the inserts 174a, 174b that are provided inside the cavities partitioned with the party wall 173 and makes a cooling medium that is guided inward blow out from the cooling holes toward inner walls of the cavities to cool impingements 128. The party wall 173 includes protrusions 176 protruding with concave curved portions 175 extending in the direction of the height of the hollow blade at the central part thereof. Further, the inserts 174a, 174b are compressed to the concave curved portions 175 of the protrusions 176 by difference in pressure of insides of partitioned rooms 133 between insides of the inserts 174a, 174b and the inner walls of the cavities to provide apical ends 177 supported air-tightly. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a turbine cooling blade such as a gas turbine or a hydrogen combustion turbine in which a cooling medium is circulated in the blade for cooling.

  In general, a gas turbine engine employs a self-driving system in which a turbine itself driven by combustion gas drives a blower or a compressor that supplies air to the combustor. An effective method for increasing the turbine output efficiency in such a system is to increase the combustion gas temperature at the turbine inlet.

  However, the upper limit of the combustion gas temperature is limited by the heat stress resistance of the materials constituting the turbine blades, particularly the first stage blades and stationary blades, or the resistance to oxidation and corrosion at high temperatures. For example, materials having high strength at high temperatures (heat-resistant superalloy materials) are used. At present, the use limit temperature of these heat-resistant superalloy materials is 800 ° C to 900 ° C under the conditions of use of the gas turbine, and high-temperature gas is used. The turbine inlet combustion gas temperature of the turbine reaches about 1300 ° C.

  Therefore, by conventionally cooling the blade to increase the gas temperature, for example, by forcibly cooling the inside of the blade using a cooling medium, the blade surface average temperature is maintained at about 800 ° C to 900 ° C. The turbine is operated at a mainstream gas temperature of about 1000 ° C to 1300 ° C.

  The prior art will be described below with reference to the drawings. First, the first prior art will be described with reference to FIGS. FIG. 31 is a transverse sectional view, and FIG. 32 is a longitudinal sectional view.

  31 and 32, the turbine cooling blade 1 impinges the inner wall surface of the blade leading edge 5 by the cooling medium supplied from the blade root 3 at the blade leading edge 2 being guided to the cooling passage 4 extending in the blade span direction. While cooling, the film is cooled by being discharged from the film holes 8 formed on the blade surfaces 6 and 7 on the blade back portion and the ventral side portion of the cooling passage 4. Further, a shower head 9 is formed on the blade leading edge 5 to cool the film.

  Similarly, forced convection cooling by the return flow passage 10 and the pin fin 11 is performed from the middle to the rear edge of the blade. That is, the cooling medium is guided to the cooling passage 12 extending in the blade span direction, and further sequentially passes through the return flow passage 10 formed on the blade trailing edge side in parallel with the cooling passage 12 to be formed on the wall surface of the final passage 13. It passes through the orifice hole 14 and flows into the blade trailing edge 15 where the pin fin 11 is provided.

  The cooling medium is further convectively cooled in the pin fins 11 and then blown out from the blade trailing edge 16. Reference numeral 17 denotes a film hole formed on the ventral wing surface of the final flow path, and reference numeral 18 denotes a plurality of ribs formed on the cooling passages 4 and 12 and the inner wall surface of the return flow flow path 10.

  With such a configuration, in the case of a turbine cooling blade having a mainstream gas temperature of about 1000 ° C. to 1300 ° C., the blade surface average temperature can be maintained at 850 ° C. by a cooling air amount of several percent of the mainstream gas flow rate. . However, in recent years, in order to increase the thermal efficiency, it has been considered that the mainstream gas temperature is operated in an atmosphere of about 1300 ° C to 1500 ° C, and that a high-efficiency hydrogen combustion turbine is operated in an atmosphere of about 1500 ° C to 2000 ° C. I came.

  In order to increase the mainstream gas temperature while maintaining the blade surface average temperature at 850 ° C. with the above-described configuration, the amount of cooling air becomes large, the thermal efficiency of the entire system is significantly reduced, and it is difficult to realize. It was.

  Recently, it has been considered that forced cooling is performed by extracting the cooling air, but it is impossible to satisfy the cooling design condition with a conventional cooling blade in an ultra-high temperature turbine exceeding 1500 ° C. .

  On the other hand, the multi-row film cooling method and the whole surface film cooling method are actively used, or the cooling medium such as water, steam, water sprayed air, inert gas, etc., which has excellent cooling performance from the air conventionally used as the cooling medium. The blades of an ultra-high temperature turbine exceeding 1500 ° C. can be cooled by changing or using forced cooling even for air cooling to cool the blades. However, although the blade can be cooled sufficiently, the cooling efficiency of the blade is increased, which increases the heat flux that passes through the blade metal and generates a large thermal stress in the blade metal part. Newly came out.

  In any case, in the turbine cooling blade having the conventional cooling structure, sufficient heat exchange cannot be performed in the flow path inside the blade through which the cooling medium passes, and effective convection cooling is not performed. There were problems such as not being able to relieve the effect and not being able to relieve the large thermal stress generated in the blade metal part.

  Next, the second prior art will be described with reference to FIG. FIG. 33 is a cross-sectional view, which is an example of an insert impingement film cooling blade structure employed mainly in a stationary blade of a gas turbine.

  In FIG. 33, a turbine cooling blade 21 accommodates impingement cooling inserts 23a and 23b in a hollow blade body 22 and impinges cooling 24 from the inside by a cooling medium, and forms a small hole array 25 on the blade surface. The material temperature is kept below the limit temperature by using a film cooling method in which the cooling medium is blown out and the blade surface is covered with a low-temperature cooling medium film compared to the combustion gas, and the thermal stress generated in the blade The structure is reduced.

  The inserts 23a and 23b and the hollow blade main body 22 are not particularly finely divided, and a small number of seal members 26 extending in the blade height direction are installed to maintain the flow distribution of the cooling medium. Yes.

  Further, the blade trailing edge portion 27 decreases in blade thickness until reaching the trailing edge 28, and inserts having the same shape as the inserts 23a and 23b in the front and intermediate portions cannot be inserted. A structure is used in which a turbulence promoter row 30 extending in the blade height direction is installed, or a plurality of small holes in the direction along the blade surface are arranged in the blade height direction although not shown. The cooling medium for convectively cooling the trailing edge portion from the inside is discharged downstream from the opening 31 at the trailing edge.

  However, if the gas turbine inlet temperature is to be increased with the aim of improving power generation thermal efficiency, the amount of cooling medium required naturally increases if the same material is used in the configuration shown in FIG. When the gas turbine inlet temperature is 1300 ° C. or higher, the cooling medium required for the entire gas turbine part is significantly increased. In the case of air cooling, it reaches 10% or more of the air compressor inlet air amount. The increase is a problem that leads to a decrease in power generation thermal efficiency and gas turbine power output, and a cooling method that satisfies a predetermined design condition is required with a cooling medium amount as small as possible.

  As described above, the life of the gas turbine cooling blade depends on the material temperature and the thermal stress generated in the material. Only by increasing the convective cooling inside the blade, the heat flux passing through the blade material is proportional to the difference between the combustion gas and the allowable blade surface temperature, so it increases as the gas turbine inlet temperature rises and is generated in the blade material. In order to increase the thermal stress, it is necessary to use a film cooling method in which cooling air is blown out from the small holes formed on the blade surface along the outer surface of the blade as in the conventional example described above.

  In this way, it is very effective from the viewpoint of blade life to use the film cooling system for the cooling blade of the high-temperature gas turbine, and in the near future development target 1500 ° C to 1700 ° C class gas turbine cooling blade, It is considered necessary to adopt the FCFC (FULL COVERAGE FILM COOLING) method in which film cooling holes are arranged on almost the entire surface.

  Now, in the FCFC cooling blade, the number of cooling medium blowing holes is greatly increased as compared with the conventional film cooling blade. However, the amount of cooling air used is not allowed to increase without limitation, and it is necessary to perform efficient cooling with the smallest amount of cooling air as described above. Therefore, it is necessary to consider comprehensively improving the cooling performance, including optimization of the film cooling performance and arrangement, as well as the inside of the film cooling hole, impingement cooling, the convection cooling effect of the turbulence promoter, and the use of an enlarged heat transfer surface aiming at the fin effect. is there.

  In film cooling, the cooling efficiency and distribution vary greatly depending on the blowing conditions to the main flow such as density ratio, mass flow rate ratio, momentum ratio, and cooling hole shape. In turbine blades, the static pressure and heat transfer coefficient of the blade outer surface change depending on the blade surface position, so there are optimum conditions for film cooling locally and locally, and attempts to demonstrate high film cooling performance with less cooling air. Then, it is necessary to finely control the blade surface distribution under the film blowing conditions according to the external conditions.

  Nonetheless, in the conventional internal cooling structure as described above, even if only the number of film cooling holes is increased, the pressure of the air chamber formed by the insert and the inner surface of the hollow blade body varies depending on the position of the film cooling holes. Since it is impossible to adjust the value, it is not possible to obtain optimum blowing conditions over the entire blade surface.

  In addition, when the impingement jet from the insert core is used to cool the blade inner wall, the impingement cooling effect increases rapidly as the crossflow between the insert core and the blade inner wall increases in a direction substantially perpendicular to the jet flow. It is known to decrease. In the internal cooling structure of the prior art, even if film cooling holes exist, cross flow of cooling air impinged upstream is inevitable as going from the leading edge to the trailing edge of the blade and going to the downstream impingement-like row However, the impingement cooling effect cannot be obtained.

  In addition, since the blade thickness at the trailing edge of the blade is significantly thinner than the leading edge and middle portion, the conventional impingement film cooling method with a high cooling effect can be used at the leading edge and middle portion. However, the pin fin cooling method and the pore cooling method are often used in combination with the trailing edge portion, which causes a decrease in cooling performance at the connecting portion of different cooling methods. This is because the conventional cooling blade cannot be provided with a substantially rectangular insert as shown in FIG. 33 in the trailing edge flow path, and if the impingement film cooling is applied to the trailing edge portion as much as possible, it is more possible. High cooling performance can be obtained.

  In this way, the insert impingement film cooling blade may be able to achieve high cooling performance by forming a controllable compartment structure inside the blade that combines impingement cooling and film cooling. The deterioration of the airtightness of the partition wall constituted by the inner surface has a problem that it is difficult to appropriately distribute the flow rate of the cooling medium. The above-mentioned seal structure tends to be considered to realize a linear seal structure in the blade height direction at first glance, but when the blade is thermally deformed, sufficient seal performance is not necessarily provided in all locations in the blade height direction. There is no guarantee of having it.

The present invention has been made in view of the situation as described above.
To provide a turbine cooling blade capable of achieving good and efficient cooling even under higher gas temperature conditions by improving the sealing performance between the insert and the blade body inner surface, and realizing improved thermal efficiency in the power generation system. It is in.

The turbine cooling blade of the present invention is
A plurality of rows of film cooling holes formed in the blade height direction on the surface of the blade body having a cavity formed therein, a partition wall partitioning the cavity into a blade front side and a blade rear side, and partitioned by the partition wall A turbine cooling blade provided with a plurality of inserts that perform impingement cooling by ejecting a cooling medium that is installed in the cavity and guided to the inner side from a cooling hole toward the inner wall surface of the cavity. And the insert is pressed against the concave curved surface portion of the projection by a pressure difference between the inside of the insert and the inner wall of the inner wall. And having a tip portion that is airtightly supported,
The insert has a large number of cuts in the direction along the blade surface at the tip portion.

  As is apparent from the above description, according to the present invention, by improving the sealing performance between the insert and the inner surface of the blade body, it is possible to perform good cooling even under higher gas temperature conditions, and to increase the cooling medium. Suppressing the effect of increasing the operating temperature of the turbine and improving the thermal efficiency of the power generation system can be achieved.

  Embodiments of the present invention and reference embodiments according to the present invention will be described below with reference to the drawings. In addition, the arrow in a figure shows the general flow of a cooling medium.

  First, one reference example relating to the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a transverse sectional view, FIG. 2 is a longitudinal sectional view, and FIG. 3 is a characteristic diagram showing a heat transfer amount with respect to a ratio between the total heat transfer area of the partition plate and the total heat transfer area of the blade inner wall surface.

  In FIG. 1 and FIG. 2, reference numeral 41 denotes a turbine cooling blade used as a moving blade. The turbine cooling blade 41 is partitioned by a partition plate 43 extending inside the blade effective portion 42 in the blade span direction, and a plurality of cooling passages 44. Is formed. The turbine cooling blade 41 is convectively cooled when the cooling medium supplied to the blade root portion 45 passes through the cooling passage 44.

  The partition plate 43 includes a total heat transfer area Af facing the cooling passage 44 and a total heat transfer area Ao of the blade inner wall surface 46 including a plate thickness t of a portion fixed to the blade inner wall surface 46 of the partition plate 43. The ratio Af / Ao is 1.5 times or more. In FIG. 3, the horizontal axis indicates the ratio Af / Ao between the total heat transfer area Af of the partition plate facing the cooling passage 44 and the total heat transfer area Ao of the blade inner wall surface 46 including the plate thickness t of the partition plate 43. This is set based on the characteristic curve X shown by taking the heat transfer amount Qf on the vertical axis.

  That is, according to the characteristic curve X, the increase rate is small as the ratio Af / Ao of the total heat transfer area increases, the increase rate is small, the increase rate increases rapidly, and the increase rate is slowed down when the ratio is increased. However, it shows an increasing trend. For this reason, in order to increase the heat transfer amount Qf, the number of the partition plates 43 may be increased. However, the increase in the heat transfer amount Qf is not linear, and there is an optimum total heat transfer area ratio Af / Ao. In order to efficiently obtain the cooling effect by the partition plate 43 and maintain the heat transfer amount Qf above that level, the ratio Af / Ao of the total heat transfer area needs to be 1.5 or more.

  Further, at least one film hole 47 is provided on the blade surface so as to penetrate from the inner wall surface side of the cooling passage 44 with respect to one cooling passage 44, and a blowing hole 48 is provided on the trailing edge of the blade. From these, the cooling medium is blown out, and super-multi-row film cooling and convection cooling are performed.

  As a result, the temperature of the turbine cooling blade 41 can be further lowered, the blade surface temperature distribution can be made uniform, and the cooling efficiency can be increased. Thereby, the gas temperature which operates the turbine cooling blade 41 can be made high, and the thermal efficiency of the whole system can be improved.

  Furthermore, since the inside of the turbine cooling blade 41 is partitioned by a large number of partition plates 43, rigidity is increased and resistance to thermal stress and centrifugal force during operation is greatly increased. Therefore, the turbine cooling blade 41 can be widely applied to large, high temperature and high load turbines. It is.

  Although not shown, when a plurality of cooling passages 44 are sequentially bent at the blade tip portion or blade root side portion, at least one portion of the cooling passage 44 communicating with at least the cooling medium blowing portion is provided. And convection cooled. The blade inner wall 46 is provided with ribs 49, which are heat transfer promoting bodies, so as to intersect the flow direction of the cooling medium, and convection cooling is performed.

  Furthermore, as a modified configuration of the cooling structure of this reference example, it may be configured to be partially combined with a turbine cooling blade having other cooling elements.

  In addition, the convection cooling effect inside the blade can be further enhanced by providing the cooling passage 44 with a partition in the blade center line direction that divides the cooling passage 44 into the back side and the abdomen side of the blade.

  Although the reference example shows the moving blade, the same applies to the stationary blade, and the cooling medium may be water vapor other than air, inert gas, liquid, or other medium.

  Furthermore, various other turbine cooling blades can be combined by combining each of the above-described modified configurations.

  Next, a second reference example will be described with reference to FIG. FIG. 4 is a cross-sectional view. In FIG. 4, the turbine cooling blade 50 is partitioned by a partition plate 52 that extends in the blade span direction of the blade effective portion 51, and a plurality of cooling passages 53 are formed.

  The partition plate 52 has a large number of protrusions 54 extending into the cooling passage 53, and intersects with a cooling medium that is supplied from the blade root portion and blows out from the film hole 47, thereby performing convection cooling.

  Similarly to the first reference example, the partition plate 52 is a blade inner wall surface including the total heat transfer area facing the cooling passage 53 and the thickness of the portion fixed to the blade inner wall surface 46 of the partition plate 52. It is formed so that the ratio to the total heat transfer area of 46 is 1.5 times or more.

  Thereby, also in this reference example, the same operation and effect as in the first reference example are obtained, and the total heat transfer area of the partition plate 52 is increased by the protrusions 54, and convection cooling is promoted, and cooling is performed more effectively. Is called.

  Next, a third reference example will be described with reference to FIG. FIG. 5 is a cross-sectional view. In FIG. 5, the turbine cooling blade 55 is partitioned by a partition plate 57 that extends in the blade span direction inside the blade effective portion 56, and a plurality of cooling passages 58 are formed.

  The partition plate 57 is provided with a large number of protrusions 59 projecting into the cooling passage 58 and extending in the blade span direction, and convection cooling is performed by a circulating cooling medium that is supplied from the blade root portion side and flows out from the film hole 47. Is called.

  Similarly to the first reference example, the partition plate 57 includes a total heat transfer area facing the cooling passage 58 and a blade inner wall surface including a plate thickness of a portion fixed to the blade inner wall surface 46 of the partition plate 57. It is formed so that the ratio to the total heat transfer area of 46 is 1.5 times or more.

  Thereby, also in this reference example, the same operation and effect as in the first reference example are obtained, and the ridge 59 increases the total heat transfer area of the partition plate 57 and promotes convection cooling, thereby further effectively cooling. Done.

  Next, a fourth reference example will be described with reference to FIG. FIG. 6 is a cross-sectional view. In FIG. 6, the turbine cooling blade 60 is partitioned by a partition plate 62 in which the blade inside of the blade effective portion 61 extends in the blade span direction, and a plurality of cooling passages 63 are formed.

  The partition plate 62 is provided with a large number of pin fins 64 that protrude into the cooling passage 63 and are arranged substantially orthogonal to the flow of the cooling medium, and are supplied from the blade root part side and are distributed by the circulating cooling medium. Convection cooling is performed.

  Similarly to the first reference example, the partition plate 62 is a blade inner wall surface including the total heat transfer area facing the cooling passage 63 and the thickness of the portion fixed to the blade inner wall surface 46 of the partition plate 62. It is formed so that the ratio to the total heat transfer area of 46 is 1.5 times or more.

  Thereby, also in this reference example, the same operation and effect as the first reference example are obtained, and the total heat transfer area of the partition plate 62 is increased by the pin fins 64, and the convection cooling is promoted. Is called.

  Next, a fifth reference example will be described with reference to FIG. FIG. 7 is a cross-sectional view. In FIG. 7, the turbine cooling blade 65 is partitioned by a partition plate 67 extending in the blade span direction inside the blade effective portion 66, and a plurality of cooling passages 68 are formed.

  The partition plate 67 has a thickness that gradually increases toward the inner central portion of the blade, and a cavity 69 in which the blade root side where the cooling medium does not flow and stays in the central portion is opened has a blade span direction. It is formed so as to extend. As a result, the cross-sectional area of the cooling passage 68 in the blade span direction is narrow at the blade inner central portion and large at the portion near the blade inner wall surface. Then, convection cooling is performed by a cooling medium that is supplied from the blade root portion side and flows out from the film hole 47 through the cooling passage 68.

  Similarly to the first reference example, the partition plate 67 is a blade inner wall surface including the total heat transfer area facing the cooling passage 68 and the thickness of the portion fixed to the blade inner wall surface 46 of the partition plate 67. It is formed so that the ratio to the total heat transfer area of 46 is 1.5 times or more.

  Thereby, also in this reference example, the same operation and effect as the first reference example are obtained, and the plate thickness of the partition plate 67 is apparently increased by providing the cavity 69, so that the concentration of thermal stress is reduced. Reduced and lighter.

  Next, a sixth reference example will be described with reference to FIG. FIG. 8 is a longitudinal sectional view. In FIG. 8, the turbine cooling blade 70 is partitioned by a partition plate 72 extending in the blade span direction in the blade effective portion 71, and a plurality of cooling passages are formed so as to constitute a return flow path. 73 is formed. A number of film holes 47 are formed on the blade surface.

  Similarly to the first reference example, the partition plate 72 includes a total heat transfer area facing the cooling passage 73 and a blade inner wall surface including a thickness of a portion fixed to the blade inner wall surface 46 of the partition plate 72. It is formed so that the ratio to the total heat transfer area of 46 is 1.5 times or more.

  Further, in the turbine cooling blade 70 configured as described above, the tip portion of the blade-shaped cylindrical blade body 75 forming the blade effective portion 71 and the blade root portion 74 is closed by the tip member 76, and the blade root portion is here. The main body internal member 77 which is partitioned from the 74 side by the partition plate 72 and forms the cooling passage 73 is accommodated, and then the insertion body 79 in which the cooling medium supply port 78 is also formed is inserted and fixed from the blade root portion 74 side. Thus, the blade root part of the blade body 75 is manufactured to be closed.

  Then, convection cooling of the turbine cooling blade 70 is performed by a cooling medium that is supplied from the supply port 78 of the blade root portion 74 to the cooling passage 73 and flows out from the film hole 47.

  In this reference example manufactured and configured in this way, the same operations and effects as those of the first reference example can be obtained.

  Next, a seventh reference example will be described with reference to FIGS. FIG. 9 is a longitudinal sectional view, and FIG. 10 is a longitudinal sectional view of a modified example of this reference example.

  In FIG. 9, reference numeral 80 denotes a turbine cooling blade that is a moving blade, which includes a blade upper shroud 82 and a blade lower shroud 83 so that the blade effective portion 81 is sandwiched therebetween, and the blade effective portion 81 is arranged in the blade span direction. A number of cooling passages 85 are formed which are partitioned by the extending partition plate 84 and have a number of film holes 47 on the blade surface.

  A cooling medium is supplied to the cooling passages 85 from the cooling medium supply port 86 of the blade upper shroud 82 via the gap 87 and from the cooling medium supply port 88 of the blade lower shroud 83 via the gap 89. Then, the cooling medium supplied to the cooling passage 85 is circulated so as to blow out from the film hole 47 and convection cooling is performed.

  Similarly to the first reference example, the partition plate 84 is a blade inner wall surface including the total heat transfer area facing the cooling passage 85 and the thickness of the portion fixed to the blade inner wall surface 46 of the partition plate 84. It is formed so that the ratio to the total heat transfer area of 46 is 1.5 times or more.

  Thereby, also in this reference example, the same operation and effect as the first reference example can be obtained.

  In the case shown in FIG. 9, the cooling passage 85 has a constant cross-sectional area of the cooling passage. However, as shown in FIG. 10, the cooling passage 91 partitioned by the partition plate 90 in the turbine cooling blade 80a has a cooling medium. You may form so that a cooling channel | path cross-sectional area may become narrow gradually along the flow of this. However, in this case as well, the partition plate 90 has a total heat transfer area of the blade inner wall surface 46 including the total heat transfer area facing the cooling passage 91 and the thickness of the portion fixed to the blade inner wall surface 46 of the partition plate 90. It is formed so that the ratio to the area is 1.5 times or more.

  In this modification, since the cooling passage 91 gradually narrows the cross-sectional area of the cooling passage along the flow of the cooling medium, the inside of the blade due to the cooling medium flow rate drop by blowing out from the blade surface of the cooling medium such as film cooling. Since a decrease in the flow velocity can be suppressed, a sufficient convection cooling effect can be obtained over a wide range of the cooling passage.

  Next, an eighth reference example relating to another embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a cross-sectional view, and FIGS. 12 to 19 are cross-sectional views showing the respective modified examples in a partially enlarged manner.

  In FIG. 11, a turbine cooling blade 101 is provided with a plurality of main cooling passages 102, 103, and 104 extending in the blade span direction substantially periodically along the blade surface so as to supply a cooling medium. The convection is cooled by flowing the cooling medium here, and the film is cooled by blowing the cooling medium from the film holes 105 and 106 to the outer surface of the blade. From the main cooling passage 103 at the rear end of the blade, the cooling medium is blown out from the blowing hole 107.

  Further, the turbine cooling blade 101 has a smaller cooling flow rate than any of the main cooling passages 102, 103, 104 between the main cooling passages 102, 103, 104, or no cooling medium flows, or no cooling medium flows. There are a plurality of sub-cooling passages 108 and 109 which are not filled with cooling medium but are parallel to each other.

  With such a configuration, the turbine cooling blade 101 with uniform blade temperature distribution and high cooling efficiency can be provided, and the sub-cooling passage that functions as a void due to thermal deformation occurring near the blade surface of the turbine cooling blade 101 It can be absorbed at 108 and 109 to suppress the generation of large thermal stress. Further, such a blade internal structure is relatively simple and can be sufficiently manufactured by the prior art.

  Furthermore, a large number of sub-cooling passages 108 and 109 are formed. For example, when employed in a moving blade, an increase in the mass of the blade effective portion can be suppressed, so that centrifugal stress due to rotation can be reduced.

  Note that the blade inner side between the main cooling passages 104a having circular passage cross-sections having no film holes as in the first modification of the present reference example shown in FIG. 12 is not limited to that shown in FIG. In addition, a turbine cooling blade 101a in which a sub-cooling passage 108a in which the apex side of a substantially triangular passage section is located on the blade surface 120 side is provided, or a second modification of the present reference example shown in the head 13 In this way, the sub-cooling passage 108b in which the apex side of the substantially triangular passage section is located on the blade surface 120 side on the blade inner side between the main cooling passages 104b having the circular passage cross-sectional shape having the film holes 105b. The turbine cooling blade 101b may be provided.

Further, as in the third modification of the present reference example shown in FIG. 14, the passage cross-sectional shape having no film hole has a circular passage cross section on the blade surface 120 side between the main cooling passages 104c having the elliptical shape. The turbine cooling blade 101c provided with the sub cooling passage 108c, and the main cooling passages 104d having an elliptical passage cross-section having a film hole 105d as in the fourth modification of the present reference example shown in FIG. The turbine cooling blade 101d may be provided with a sub-cooling passage 108d having a circular passage section on the blade surface 120 side.

  Further, as in the fifth modified example of the present reference example shown in FIG. 16, the main cooling passage 104e is provided so that the passage cross-sectional shape having no film hole is oblong and the long axis is along the blade surface 120, Like the turbine cooling blade 101e in which a sub-cooling passage 108e having a circular passage section is provided between the main cooling passage 104e and the blade surface 120, or a sixth modification of the present reference example shown in FIG. The main cooling passage 104f has an oval cross-sectional shape having a film hole 105f, the long axis is provided along the blade surface 120, and a circular passage cross section is provided between the main cooling passage 104f and the blade surface 120. The turbine cooling blade 101f may be provided with the auxiliary cooling passage 108f.

  Further, as in the seventh modification of the present reference example shown in FIG. 18, the secondary passage having a circular passage cross section having a substantially the same diameter between the main cooling passages 104g having a circular passage sectional shape having no film hole. A turbine cooling blade 101g in which a cooling passage 108g is provided, or a main cooling passage 104d having a circular passage cross-section having a film hole 105h as in the eighth modification of the present reference example shown in FIG. Alternatively, the turbine cooling blade 101h may be provided with a sub-cooling passage 108h having a circular passage section having substantially the same diameter.

  Next, a ninth reference example relating to yet another reference embodiment related to the present invention will be described with reference to FIGS. 20 is a cross-sectional view of the center of the blade, FIG. 21 is a partially enlarged perspective view, and FIGS. 22 to 27 are partially enlarged perspective views showing modifications.

  20 and 21, the turbine cooling blade 121 is partitioned into a blade front portion 124 side and a blade intermediate portion 125 side by a partition wall 123 provided in the blade span direction in the hollow blade body 122. The impingement cooling inserts 126a and 126b are accommodated in the partitioned portions 124 and 125 so as to be spaced apart from the blade inner wall surface.

  Then, for example, the hollow wing body 122 is impingement cooled 128 by the small holes 127 formed in the inserts 126a and 126b from the inside by the cooling medium supplied into the inserts 126a and 126b from the blade root portion, and penetrates the blade surface. The material temperature is obtained by a method using a so-called film cooling 130 in which cooling air, which is a cooling medium, is blown out through the small hole row 129 formed so as to cover the blade surface with a low-temperature cooling medium film as compared with the combustion gas. Is kept below the critical temperature, and the thermal stress generated in the blade is reduced.

  In order to store the inserts 126a and 126b at predetermined intervals with respect to the inner wall surface of the blade, the cross-sectional shape is substantially trapezoidal from the inner wall of the hollow blade body 122 (the upstream side is perpendicular to the inner wall and the downstream side is inclined). A plurality of projecting walls 131 extending in the blade height direction are protruded, and the inserts 126a and 126b are held by the flat top portions 132 so that the opposing surfaces are pressed against each other. It is supposed to be. As a result, a large number of compartments 133 are formed between the adjacent protruding walls 131 along the blade surface direction, and each compartment 133 is formed so that the flow of the cooling medium between the adjacent compartments 133 is reduced. .

  The inner surface of the hollow blade main body 122 corresponding to each compartment 133 is impingement cooled 128 by the small holes 127 separated by the respective compartments 133, and the cooling medium is supplied from the film cooling holes 129 provided in the respective compartments 133. It is blown out of the wing. In the film cooling 130, it is known that it is effective for improving the cooling effect to make the blowing direction of the cooling medium close to the blade surface, and in this reference example, the film cooling hole 129 is also in the downstream direction of the blade outer surface gas flow. To erupt diagonally.

  The film cooling hole 129 is formed so as to pass through the inside of the protruding wall 131 from the side wall 134 substantially perpendicular to the inner surface of one of the blades 131 in the compartment 133 and open toward the outer surface of the blade. For this reason, the internal heat transfer surface area in the film cooling hole 129 is large, and the convection cooling capacity by the cooling medium flowing therethrough is high. Further, the cooling medium blown into the compartment 133 by the impingement cooling 128 by the inclined wall 135 of the other protruding wall 131 in the compartment 133 is reflected in the direction of the one substantially vertical side wall 134, and enters the film cooling hole 129. It is supplied efficiently.

  In addition, since the blade surface static pressure distribution and the heat conductivity distribution, which have a large influence on the blowout of the film cooling 130, change mainly in the direction along the blade surface, the blade surface on the lower portion of the hollow blade body 122 as in this reference example. The structure provided with divided compartments 133 in the direction along the direction can finely control the distribution of the cooling medium for performing film cooling 130 ejected from each compartment 133, resulting in high cooling performance and effective use of the cooling medium. Will contribute.

  Furthermore, in this reference example, two inserts 126a and 126b are installed inside the blade, and the blade rear portion 136 is cooled by installing a pin fin row 140 at a portion where the blade thickness decreases until reaching the trailing edge 139. Of course, a turbulence promoter array extending in the blade height direction or a structure in which a large number of small holes in the direction along the blade surface are arranged in the blade height direction may be used. In this reference example, the convective cooling medium at the rear end portion is discharged downstream from the opening 141 at the rear edge 139.

  Next, a modification of this reference example will be described. FIG. 22 shows a first modification in which the inserts 126a and 126b are omitted, and this includes a rib wall 142 extending in a direction substantially along the blade surface between the protrusion walls 131 inside the hollow blade main body 122a. It has a structure. By adding the ridge wall 142, a compartment 133a divided in the blade height direction is formed. The blade surface static pressure distribution and heat transfer coefficient distribution, which have a great influence on the blowout of the film cooling 130, change mainly in the direction along the blade surface, but the gas temperature has a strong distribution of several hundred degrees Celsius in the blade height direction. Have. Therefore, if the rib wall 142 that realizes such division in the blade height direction is added and used, it contributes to a further reduction in the amount of the cooling medium that can realize a finer distribution of the cooling medium flow rate.

  Further, since the rib wall 142 also functions as an enlarged heat transfer surface (fin) extending from the blade surface to the compartment 133a at the same time, it is obvious that it contributes to the improvement of the convection cooling effect from the inner surface of the compartment 133a. Needless to say, the rib wall 142 need only be provided at a necessary portion, and the installation position does not have to be a fixed position in the blade height direction, and may be arranged at alternate positions as shown.

  Furthermore, although one compartment 133a has three film cooling holes 129, this number is of course not limited to this, and in the finest configuration, each compartment 133a has one film cooling hole. But you can. In addition, although not shown, it is of course possible to form film cooling holes 129 at locations where the projecting walls 131 do not exist on the surface of the hollow blade main body 122a to increase the number of film cooling holes 129. Even in such a case, if the cooling structure is such that the inner surface of the hollow blade main body 122a is partitioned into a plurality of compartments 133a, a design that minimizes the influence on the cooling performance of other parts of the blade (compartments) can be easily performed. . In other words, with the configuration in which the number of film cooling holes 129 is increased only by a part of the blade surface, the cooling performance of this part can be easily improved.

  FIG. 23 is a second modified example in which the inserts 126a and 126b are omitted. From the inner wall of the hollow blade main body 122b, a large number of protruding walls extending in the blade height direction with a substantially rectangular cross-section. 131b is provided so as to protrude, and triangular protrusions 143 and 144 are formed on the protruding wall 131b in the trailing edge direction along the blade surface. The comb-tooth shaped portion 143 has the same height from the main portion of the projection wall 131b toward the downstream, but the comb-tooth shaped portion 144 reduces the height.

  A film cooling hole 129 is formed inside the protruding wall 131b. According to this configuration, the thickness of the surface member of the hollow blade main body 122b forming the compartment 133a can be thinly formed close to the protruding wall 131b, and the thermal resistance of the blade member is reduced. This is an effective configuration when the formation density of the film cooling holes 129 is low and the cooling effect of impingement cooling is high.

  Further, since the comb-tooth shaped parts 143 and 144 are formed, it also functions as an enlarged heat transfer surface (fin) of the surface member of the hollow blade main body 122b. In other words, if the impingement cooling hole 129 (not shown) is arranged around the portion sandwiched between the comb-shaped portions 143 and 144, the cooling medium that has collided with the blade inner surface of the surface member of the hollow blade main body 122b is comb-shaped portions. After being guided to 143 and 144 and flowing to the right side in the drawing, colliding with the comb-like portions 143 and 144, being blown out of the blade from the film cooling hole 129, flowing to the right side in the drawing and after colliding with the main part of the projection wall 131b It is apparent that the main portion of the projection wall 131b and the comb-like portions 143 and 144 are jetted out of the film cooling hole 129 and are good expanded heat transfer surfaces.

  FIG. 24 shows a third modification in which the inserts 126a and 126b are omitted, and the cross-sectional shape of the main part from the inner wall of the hollow blade main body 122c is substantially trapezoidal (the upstream side is perpendicular to the inner wall and the downstream side is inclined. A plurality of projecting walls 131c extending in the blade height direction so as to protrude, and the projecting wall 131c has a triangular comb-tooth shaped portion 145 extending in the front edge direction along the blade surface. , 146 are formed. The comb-tooth shaped portion 145 has the same height from the main portion of the protruding wall 131c toward the upstream, but the comb-tooth shaped portion 146 reduces the height.

  A film cooling hole 129 is formed inside the protruding wall 131c, and the film cooling hole 129 is opened at a portion sandwiched between the comb-like portions 145 and 146. For this reason, there is an effect that the flow of the cooling medium is surely introduced into the film cooling hole 129, and the film cooling efficiency is relatively lowered due to the high-speed flow flowing into the film cooling hole 129 while accelerating. The portion immediately upstream of the hole 129 has an action of cooling in consideration of the fin effect of the comb-like portions 145 and 146.

  FIG. 25 shows a fourth modification in which the inserts 126a and 126b are also omitted. From the inner wall of the hollow blade main body 122d, a large number of protruding walls extending in the blade height direction with a substantially rectangular cross-sectional shape. 131d is provided so as to protrude, and triangular comb teeth 143, 144 are formed on the protruding wall 131d in the trailing edge direction along the blade surface, and the triangular comb is formed in the leading edge direction. Tooth-like portions 145 and 146 are formed.

  For this reason, the effect similar to the 2nd, 3rd modification is acquired.

  FIG. 26 shows a fifth modification in which a film cooling hole 129e penetrating the protruding wall 131 formed in the hollow blade main body 122e is protruded from the side wall 134 substantially perpendicular to the inner surface of one of the protruding walls 131 in the compartment 133. The wall 131 is drilled so as to penetrate the blade 131 in the blade height direction and open in the blade outer surface direction.

  In a turbine cooling blade having a large number of film cooling holes 129e typified by FCFC, the internal surface area of the film cooling holes 129e is increased, so that a configuration that enhances the convection cooling effect and realizes higher cooling performance is important. According to this configuration, by inclining the film cooling hole 129e by 45 degrees in the blade height direction, the internal heat transfer surface area is increased by about 40%, and as a result, the film cooling effect immediately below the film cooling hole 129e is relatively low. There is an effect of improving the cooling performance.

  FIG. 27 shows a sixth modification in which the cross-sectional shape is substantially trapezoidal from the inner wall of the hollow blade main body 122f (the upstream side is perpendicular to the inner wall and the downstream side is inclined) and extends in the blade height direction. The projecting wall 131f is provided so as to protrude, and the top portion 147 is formed with a seal recess 148 formed by a large number of fine grooves, dents, etc. in the extending direction. 126a and 126b are held so that the opposing surfaces are pressed against each other. As a result, a large number of compartments 133 are formed along the blade surface direction between the adjacent protruding walls 131f, and each compartment 133 has improved sealing performance between the adjacent compartments 133 and the circulation of the cooling medium is reduced. Formed as follows.

  By forming the seal recess 148, a structure that reduces the leakage of the cooling medium through the minute space between the protruding wall 131f and the inserts 126a and 126b is realized. The seal recess 148 is a fine one formed perpendicular to the direction in which the leak flow is likely to occur, and has an effect of reducing the leak flow rate by separating the flow and increasing the pressure loss when the leak flow is about to occur. .

  Next, a tenth reference example of the present invention will be described with reference to FIG. FIG. 28 is a cross-sectional view of the main part. In FIG. 28, the turbine cooling blade 151 is a blade front portion and a blade intermediate portion 153 (not shown) of the hollow blade body 152, respectively. The insert cooling insert is accommodated and impingement cooling and film cooling are performed.

  Further, the blade rear portion 154 is separated from the blade intermediate portion 153 by a partition wall 155. The isolated blade rear portion 154 is formed with a hollow portion whose thickness is reduced to the trailing edge 156, and an insert 157 is formed in the hollow portion on the inner wall of the blade in the height direction of the blade. The walls 131 are accommodated such that a predetermined interval is provided with respect to the inner wall surface of the blade and a partition 133 is provided between the protruding walls 131.

  Then, a cooling medium is supplied into the insert 157 from the blade root part, and the blade back side 158 and the blade belly side 159 are partly inside the blade rear side 154 of the hollow blade main body 152 due to the cooling medium. The impingement cooling 128 is performed by small holes (not shown) formed in the insert 157 from the side, and film cooling 130 is performed on the blade surface through the small hole row 129 formed so as to penetrate the blade surface.

  Further, the insert 157 has an extension 160 that extends the surface of the blade belly side 159 in the trailing edge direction, and the trailing edge of the substantially rectangular insert 157 from the direction of the blade back side 158 where the insert 157 is interrupted. The cooling medium is supplied to the impingement passage 162 at the trailing edge through the cooling medium passage 161 formed in the above. Then, impingement cooling 128 is performed by a cooling medium supplied to the impingement passage 162 through a small hole (not shown) formed in the extension 160 of the insert 157. In addition, there is a possibility that a cross flow is formed in the impingement passage 162 on the ventral side of the rear part of the blade, and in that case, a part of the cooling medium may be ejected from the film cooling hole 129 formed on the surface to the outer surface of the blade.

  In addition, the cooling medium supplied to the ventral impingement cooling passage 162 at the rear of the blade and a part or all of the cooled cooling medium are discharged from the trailing edge blowout port 141 to the downstream of the blade row. In this embodiment, a row of pin fins 140 is installed at the rear edge portion to position the insert 157. Further, for example, a protruding turbulence promoter 163 is installed on the inner wall surface of the impingement passage 162 formed in the blade back side rear edge portion to promote convective heat transfer.

  As a result, the turbine cooling blade 151 can perform the impingement cooling 128 also on the blade rear portion 154, and the cooling effect is further improved.

  Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 29 is a cross-sectional view of the center of the blade, and FIG. 30 is an enlarged perspective view of the main part.

  29 and 30, the turbine cooling blade 171 is divided into a blade front portion 124 side and a blade intermediate portion 125 side by a partition wall 173 provided in the blade span direction in the hollow blade body 172. The impingement cooling inserts 174a and 174b are accommodated in the partitioned portions 124 and 125 so as to be spaced apart from the blade inner wall surface.

  The partition wall 173 is provided with a projection 176 at the center portion thereof, which protrudes with a smooth concave curved surface portion 175 extending in the blade height direction, on the blade front portion 124 side and the blade intermediate portion 125 side. On the other hand, the tip portions 177 of the inserts 174a and 174b in contact with the partition wall 173 have elastic deformation and restoring force, the pressure of the cooling medium supplied into the inserts 174a and 174b, and the pressure inside the compartment 133 lower than this pressure. By being pressed against the concave curved surface portion 175 by the difference, an airtight seal structure is realized. As a result, the material temperature of the turbine cooling blade 171 reaches a maximum of 800 ° C. to 900 ° C. under operating conditions, but the inserts 174a and 174b are kept at a low temperature close to the cooling medium temperature. As a result, the hollow blade main body 172 and the inserts 174a and 174b are maintained. A gap due to a difference in thermal expansion is likely to occur between the two, but the formation of this gap is prevented.

  The tip portion 177 is provided with a number of cuts 178 in the direction along the blade surface. Thus, even if the partition wall 173 undergoes some three-dimensional deformation, the tip portions 177 of the inserts 174a and 174b can follow the deformation for each short portion by the notch 178. This prevents the unexpected leakage of the cooling medium, resulting in effective use of the cooling medium. It should be noted that sufficient sealing performance can be obtained even if there is no notch 178 in the tip portion 177 of the inserts 174a and 174b under conditions where the thermal deformation of the hollow blade body 172 is small.

  As described above, according to another embodiment of the present invention related to the present invention shown by the embodiment of the present invention and the ninth and tenth reference examples, the film cooling, impingement cooling and convection cooling effects are achieved. For example, even when the temperature of the gas turbine is increased, good cooling can be performed by improving the sealing performance, the increase of the cooling medium can be suppressed, and a high-temperature gas turbine with a small amount of medium can be manufactured. Further, the thermal efficiency of a system such as a simple cycle or combined cycle power plant using the gas turbine is also improved.

It is a cross-sectional view of a turbine cooling blade showing a first reference example of the present invention. It is a longitudinal cross-sectional view of the turbine cooling blade which shows the 1st reference example of this invention. It is a characteristic view which shows the heat-transfer amount with respect to ratio of the total heat-transfer area of the partition plate which concerns on the 1st reference example of this invention, and the total heat-transfer area of a blade inner wall surface. It is a cross-sectional view of the turbine cooling blade which shows the 2nd reference example of this invention. It is a cross-sectional view of the turbine cooling blade which shows the 3rd reference example of this invention. It is a cross-sectional view of the turbine cooling blade which shows the 4th reference example of this invention. It is a cross-sectional view of the turbine cooling blade which shows the 5th reference example of this invention. It is a longitudinal cross-sectional view of the turbine cooling blade which shows the 6th reference example of this invention. It is a longitudinal cross-sectional view of the turbine cooling blade which shows the 7th reference example of this invention. It is a longitudinal cross-sectional view which shows the modification of the turbine cooling blade which concerns on the 7th reference example of this invention. It is a cross-sectional view of the turbine cooling blade which shows the 8th reference example of this invention. It is a partial expanded cross-sectional view which shows the 1st modification of the turbine cooling blade which concerns on the 8th reference example of this invention. It is a partial expanded cross-sectional view which shows the 2nd modification of the turbine cooling blade which concerns on the 8th reference example of this invention. It is a partial expanded cross-sectional view which shows the 3rd modification of the turbine cooling blade which concerns on the 8th reference example of this invention. It is a partial expanded cross-sectional view which shows the 4th modification of the turbine cooling blade which concerns on the 8th reference example of this invention. It is a partial expanded cross-sectional view which shows the 5th modification of the turbine cooling blade which concerns on the 8th reference example of this invention. It is a partial expanded cross-sectional view which shows the 6th modification of the turbine cooling blade which concerns on the 8th reference example of this invention. It is a partial expanded cross-sectional view which shows the 7th modification of the turbine cooling blade which concerns on the 8th reference example of this invention. It is a partial expanded cross-sectional view which shows the 8th modification of the turbine cooling blade which concerns on the 8th reference example of this invention. It is a cross-sectional view of the blade center of a turbine cooling blade showing a ninth reference example of the present invention. It is a partial expansion perspective view of the turbine cooling blade which shows the 9th reference example of this invention. It is a partial expansion perspective view which shows the 1st modification of the turbine cooling blade which concerns on the 9th reference example of this invention. It is a partial expansion perspective view which shows the 2nd modification of the turbine cooling blade which concerns on the 9th reference example of this invention. It is a partial expansion perspective view which shows the 3rd modification of the turbine cooling blade which concerns on the 9th reference example of this invention. It is a partial expansion perspective view which shows the 4th modification of the turbine cooling blade which concerns on the 9th reference example of this invention. It is a partial expansion perspective view which shows the 5th modification of the turbine cooling blade which concerns on the 9th reference example of this invention. It is a partial expansion perspective view which shows the 6th modification of the turbine cooling blade which concerns on the 9th reference example of this invention. It is a principal part cross-sectional view of the turbine cooling blade which shows the 10th reference example of this invention. It is a cross-sectional view of the blade center of the turbine cooling blade showing an embodiment of the present invention. It is an expansion perspective view of the principal part of the turbine cooling blade which shows one Example of this invention. It is a cross-sectional view of a turbine cooling blade showing the first prior art. It is a longitudinal cross-sectional view of the turbine cooling blade which shows a 1st prior art. It is a cross-sectional view of the turbine cooling blade which shows a 2nd prior art.

Explanation of symbols

128 ... impingement cooling 129 ... small hole row 133 ... compartment 172 ... hollow wing body 173 ... partition wall 174a, 174b ... insert 175 ... concave curved surface portion 176 ... projection 177 ... tip portion

Claims (2)

  A plurality of rows of film cooling holes formed in the blade height direction on the surface of the blade body having a cavity formed therein, a partition wall partitioning the cavity into a blade front side and a blade rear side, and partitioned by the partition wall A turbine cooling blade provided with a plurality of inserts that perform impingement cooling by ejecting a cooling medium that is installed in the cavity and guided to the inner side from a cooling hole toward the inner wall surface of the cavity. And the insert is pressed against the concave curved surface portion of the projection by a pressure difference between the inside of the insert and the inner wall of the inner wall. A turbine cooling blade having a tip portion that is airtightly supported.   The turbine cooling blade according to claim 1, wherein the insert has a plurality of cuts in a direction along a blade surface at the tip portion.

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