Double-walled vane for a gas turbine and gas turbine

Abstract

The application discloses a double-wall blade for a gas turbine and the gas turbine, and the blade comprises an outer shell and a plurality of inner walls, the outer shell defines a cavity, a plurality of air outlet slots extending along the length direction of the blade are arranged on the outer shell, the openings of the air outlet slots are directed to the trailing edge of the outer shell, the blade is provided with an air inlet communicating with the cavity, the plurality of inner walls are arranged in the cavity in the circumferential direction and connected with the outer shell, the outer wall surface of the plurality of inner walls and the inner wall surface of the outer shell form a plurality of cooling channels, the inner wall is provided with at least one through hole communicating the cooling channels with the cavity, and the end of the plurality of cooling channels close to the trailing edge of the outer shell is communicated with the plurality of air outlet slots one by one. The double-wall blade disclosed by the application uses the cooling mode combining impingement cooling and air film cooling, greatly improves the cooling effect of the cooling air on the high-temperature blade, and enables the blade to have strong heat exchange capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbines, and further relates to a double-wall blade for a gas turbine and a gas turbine. BACKGROUND

[0002] A gas turbine is an important power machine, and is widely used in aviation propulsion, ship propulsion, power generation and other fields. The turbine inlet temperature of the gas turbine is much higher than the heat-resistant limit temperature of high-temperature alloy, and corresponding measures must be taken to reduce the blade operating temperature, so that blade cooling becomes one of the major key technologies for ensuring the safe and reliable operation of the gas turbine.

[0003] The high-temperature blade of the turbine generally adopts a hollow structure, and the inside of the blade is cooled by high-pressure gas extracted from the compressor. The currently widely used blade cooling methods mainly include impingement cooling, ribbed channel cooling, column rib cooling, and film cooling, but the heat transfer enhancement capacity of these cooling methods is still limited and cannot meet the operating conditions of advanced gas turbines with higher heat loads. Moreover, with the development of technology over the past few decades, the research on the above-mentioned cooling methods has been relatively sufficient, and the cooling effect has reached the technical limit. If the cooling effect is to be greatly improved, the existing typical internal structure of the blade is difficult to achieve. SUMMARY

[0004] The present application aims to at least partially solve one of the problems in the related art. To this end, the embodiments of the present application propose a double-wall blade for a gas turbine with excellent cooling effect. The embodiments of the present application also propose a gas turbine.

[0005] The double-wall blade for a gas turbine provided by the embodiments of the present application comprises an outer shell defining a cavity, a plurality of gas outlet slots extending along the length direction of the blade are arranged on the outer shell, the openings of the gas outlet slots face the trailing edge of the outer shell, and the blade has an air inlet communicating with the cavity; a plurality of inner walls are arranged in the cavity in a circumferential direction and connected with the outer shell, the outer wall surface of the plurality of inner walls and the inner wall surface of the outer shell form a plurality of cooling channels, the inner wall is provided with at least one through hole communicating the cooling channels and the cavity, and the end portions of the plurality of cooling channels close to the trailing edge of the outer shell communicate with the plurality of gas outlet slots one by one.

[0006] The double-wall blade for a gas turbine provided by the embodiment of the present application has a double-wall structure, a plurality of cooling channels are formed between an outer shell and a plurality of inner walls, and cooling gas flows out of the blade from a slot close to the surface of the outer shell after passing through the cooling channels, forming a gas film covering the outer surface of the outer shell and producing the effect of gas film cooling. The cooling gas is uniformly attached to the surface of the outer shell, which can better prevent high-temperature gas from directly contacting the outer surface of the outer shell. Meanwhile, the cooling gas is sprayed into the cooling channels through the through holes on the inner walls, which can play a role of impact cooling on the inner surface of the outer shell.

[0007] In addition, the cooling gas in different cooling channels is discharged through corresponding gas outlet slots formed on the outer shell, which reduces the cross flow of the gas in the cooling channels and further reduces the weakening effect of the cross flow on the impact cooling, greatly improving the cooling efficiency and heat exchange capacity.

[0008] Therefore, the double-wall blade provided by the embodiment of the present application uses a cooling form combining impact cooling and gas film cooling, greatly improves the cooling effect of the cooling gas on the high-temperature blade, and makes the blade have strong heat exchange capacity.

[0009] In some embodiments, the gas outlet slot includes at least a first gas outlet slot arranged on the suction surface of the outer shell, a second gas outlet slot arranged on the pressure surface of the outer shell, and a third gas outlet slot arranged at the trailing edge of the outer shell, and the first gas outlet slot and the second gas outlet slot are each at least one.

[0010] In some embodiments, the inner wall includes at least a first inner wall opposite to the leading edge of the outer shell, and the first inner wall and the outer shell form a first cooling channel therebetween, the first cooling channel has opposite first and second ends in the extension direction thereof, the first end is in communication with the first gas outlet slot, and the second end is in communication with the second gas outlet slot.

[0011] In some embodiments, the first inner wall is provided with a plurality of through holes at least at a position opposite to the leading edge.

[0012] In some embodiments, the first inner wall is opposite to the leading edge, a part of the suction surface, and a part of the pressure surface, and the first inner wall is further provided with a plurality of through holes at a position opposite to the suction surface and the pressure surface.

[0013] In some embodiments, the gas outlet slot has opposite first and second side walls, and the side of the inner wall close to the gas outlet slot is smoothly connected with the first side wall of the gas outlet slot.

[0014] In some embodiments, a column rib structure is arranged in the cooling channel, and the column rib structure includes a plurality of column ribs, one end of the column rib is connected with the outer shell, and the other end of the column rib is connected with the inner wall.

[0015] In some embodiments, the column ribs are prisms.

[0016] In some embodiments, the column ribs are offset in the direction of cooling gas flow.

[0017] A gas turbine according to another embodiment of the present invention includes blades according to any of the above embodiments. Attached Figure Description

[0018] Figure 1 This is a profile view of the blades of a gas turbine provided in an embodiment of the present invention.

[0019] Figure 2 This is an AA cross-sectional view of the blades of a gas turbine provided in an embodiment of the present invention.

[0020] Figure 3 yes Figure 2 BB cross-sectional view.

[0021] Figure 4 This is a schematic diagram of a column rib structure provided in one embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of a column rib structure provided in another embodiment of the present invention.

[0023] Figure label:

[0024] 100 leaves

[0025] 1. Outer shell, 11. First air outlet slot, 111. Second air outlet slot, 112. Third air outlet slot, 113. Air inlet, 12. Inner wall, 2. First inner wall, 201. Second inner wall, 202. Third inner wall, 203. Cooling channel, 21. First cooling channel, 211. Through hole, 22. Leading edge, 3. Tail edge, 4. Pressure surface, 5. Suction surface, 6. Column rib, 7. Partition plate, 8. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The following is based on Figures 1-5 This invention describes a double-walled blade 100 for a gas turbine, provided by an embodiment of the present invention. The blade 100 includes an outer shell 1 and several inner wall sections 2. The outer shell 1 has a leading edge 3 and a trailing edge 4. As will be known to those skilled in the art, the leading edge 3 is the wider side of the outer contour of the outer shell 1, and the trailing edge 4 is the narrower side of the outer contour of the outer shell 1. The two outer wall surfaces of the outer shell 1 are an inwardly recessed pressure surface 5 and an outwardly protruding suction surface 6, respectively.

[0028] The shell 1 defines a chamber, and a plurality of air outlet slots 11 are arranged on the shell 1 and extend along the length direction of the blade 100 and are arranged at intervals in the circumferential direction of the shell 1. In addition, the air outlet slots 11 are open towards the trailing edge 4 of the shell 1, that is, the air outlet slots 11 are open rearward, and the blade 100 further has an air inlet 12 which is in communication with the chamber of the shell 1, and cooling air enters the chamber of the shell 1 from the air inlet 12 and is sprayed out of the air outlet slots 11.

[0029] A plurality of inner walls 2 are arranged in the chamber of the shell 1 and are connected to the shell 1 in the circumferential direction of the shell 1, and a plurality of cooling channels 21 are formed between the outer wall surface of the inner walls 2 and the inner wall surface of the shell 1, and at least one through hole 22 is arranged on the inner wall 2 and is in communication with the chamber of the shell 1 and the cooling channel 21, and the end of each cooling channel 21 close to the trailing edge 4 of the shell 1 is in communication with one air outlet slot 11. After the cooling air enters the chamber of the shell 1 from the air inlet 12, it is sprayed into the cooling channel 21 through the through hole 22 on the inner wall 2, and flows rearward along the cooling channel 21, that is, flows towards the trailing edge 4, and is finally discharged from the air outlet slot 11 which is in communication with the end of the cooling channel 21. Since the air outlet slots 11 are open rearward, the cooling air forms an air film on the outer surface of the shell 1, thereby achieving air film cooling.

[0030] The double-wall blade for a gas turbine provided by the embodiment of the present application has a double-wall structure, a plurality of cooling channels are formed between the shell and the plurality of inner walls, and the cooling air flows through the cooling channels and is discharged from the slots close to the wall surface of the shell, thereby forming an air film covering the outer surface of the shell and achieving air film cooling. The cooling air is uniformly attached to the surface of the shell, thereby better preventing the high-temperature gas from directly contacting the outer surface of the shell. In addition, the cooling air is sprayed into the cooling channels through the through holes on the inner walls, thereby achieving impingement cooling of the inner wall surface of the shell.

[0031] In addition, the cooling air in different cooling channels is discharged through corresponding air outlet slots arranged on the shell, thereby reducing the cross flow of the gas in the cooling channels and further reducing the weakening effect of the cross flow on the impingement cooling, thereby greatly improving the cooling efficiency and heat exchange capacity.

[0032] Therefore, the double-wall blade provided by the embodiment of the present application uses a cooling form combining impingement cooling and air film cooling, thereby greatly improving the cooling effect of the cooling air on the high-temperature blade and enabling the blade to have a strong heat exchange capacity.

[0033] For the convenience of description, the length direction of the blade 100 shown in Figure 2 is taken as the up-down direction, and the leading edge-trailing edge direction is taken as the front-rear direction, and the technical solutions of the embodiment of the present application are described, and the up-down direction and the front-rear direction are indicated by arrows in Figure 2 .

[0034] In some embodiments, the air outlet slots 11 include at least a first air outlet slot 111 provided on the suction surface 6, a second air outlet slot 112 provided on the pressure surface 5, and a third air outlet slot 113 provided at the trailing edge 4, and the first air outlet slot 111 and the second air outlet slot 112 are each at least one.

[0035] In Figure 3 In the illustrated embodiment, the first air outlet slot 111 on the suction surface 6 is one, and the second air outlet slot 112 on the pressure surface 5 is two.

[0036] Of course, in other embodiments, the number of first air outlet slots 111 can be other, for example, two or more, and the number of second air outlet slots 112 can be other, for example, one or more.

[0037] As Figure 3 illustrated, the openings of the first air outlet slot 111, the second air outlet slot 112 and the third air outlet slot 113 all face backward (as indicated by the arrows in Figure 3 , so that the cooling air ejected from the air outlet slots 11 flows backward, forming an air film covering the outer surface of the outer shell 1, and achieving the effect of air film cooling.

[0038] In some embodiments, the inner wall 2 includes a first inner wall 201, which is at least opposite the leading edge 3, in other words, at least a portion of the first inner wall 201 is opposite the leading edge 3. In Figure 3 the illustrated embodiment, a portion of the first inner wall 201 is opposite the leading edge 3, another portion is opposite the pressure surface 5, and another portion is opposite the suction surface 6. The first inner wall 201 and the outer shell 1 form a first cooling channel 211 therebetween, which has opposite first and second ends in its extension direction. The first end of the first cooling channel 211 communicates with the first air outlet slot 111 on the suction surface 6, and the second end of the first cooling channel 211 communicates with the second air outlet slot 112 on the pressure surface 5.

[0039] In Figure 3 the illustrated embodiment, a portion of the first cooling channel 211 flows through the inner wall surface of the outer shell 1 corresponding to the leading edge 3, a portion flows through the inner wall surface of the outer shell 1 corresponding to the pressure surface 5, and another portion flows through the inner wall surface of the outer shell 1 corresponding to the suction surface 6, to carry away heat and cool the outer shell 1. And the cooling air in the first cooling channel 211 flows backward, a portion flows to the first end and is ejected from the first air outlet slot 111, forming air film cooling on the suction surface 6, and another portion flows to the second end and is ejected from the second air outlet slot 112, forming air film cooling on the pressure surface 5.

[0040] In some embodiments, the first inner wall 201 is provided with a plurality of through holes 22 at a position opposite to the leading edge 3. When the cooling gas is injected into the first cooling passage 211 through the plurality of through holes 22 opposite to the leading edge 3, the leading edge 3 is subjected to good impingement cooling.

[0041] Further, in some embodiments, as shown in Figure 3 , the first inner wall 201 is also provided with a plurality of through holes 22 at a position opposite to the suction surface 6 and the pressure surface 5. That is, in the embodiment shown in Figure 3 , the first inner wall 201 is provided with the plurality of through holes 22 capable of subjecting the leading edge 3 to impingement cooling, and is also provided with the plurality of through holes 22 capable of subjecting the suction surface 6 and the pressure surface 5 to impingement cooling. The cooling gas injected into the first cooling passage 211 through the through holes 22 provided on the first inner wall 201 flows backward along the first cooling passage 211, in the process of which the cooling gas contacts the inner wall surface of the outer shell 1, takes away heat, and enhances the heat exchange effect.

[0042] In some embodiments, the gas outlet slot 11 has opposite first and second side walls, and the side of the inner wall 2 close to the gas outlet slot 11 is smoothly connected to the first side wall of the gas outlet slot 11, so that the gas in the cooling passage 21 can be more smoothly ejected from the corresponding gas outlet slot 11 without changing the flow direction.

[0043] As an example, as shown in Figure 3 , the two parts of the outer shell 1 are separated to form a gap, one of the two parts is inwardly offset to form the gas outlet slot 11, and the end of the corresponding inner wall 2 is smoothly connected to one of the side walls (the first side wall) of the gas outlet slot 11, i.e., the end of the inner wall 2 is smoothly connected to the part of the outer shell 1 close to the gas outlet slot 11.

[0044] In the embodiment shown in Figure 3 , the first and second ends of the first inner wall 201 are smoothly connected to the first side walls of the corresponding gas outlet slots 11. The inner wall of the blade 100 further includes a second inner wall 202 corresponding to another second gas outlet slot 112, and a third inner wall 203 corresponding to a third gas outlet slot 113.

[0045] The rear end (the side close to the second gas outlet slot 112) of the second inner wall 202 is smoothly connected to the wall surface of the outer shell 1 near the second gas outlet slot 112. The front end (the side away from the second gas outlet slot 112) of the second inner wall 202 is connected to the inner wall surface of the outer shell 1 through the partition plate 8. The rear end (the side close to the third gas outlet slot 113) of the third inner wall 203 is connected to the wall surface of the outer shell 1 near the third gas outlet slot 113, and the front end (the side away from the third gas outlet slot 113) of the third inner wall 203 is connected to the inner wall surface of the outer shell 1 through another partition plate 8.

[0046] The first inner wall 201, the second inner wall 202 and the third inner wall 203 are distributed around the inner wall surface of the outer shell 1, forming a cooling channel which basically surrounds the outer shell 1, so as to maximize the heat exchange area of the cooling gas and maximize the cooling effect.

[0047] In some embodiments, the cooling channel 21 is provided with a column rib structure, which includes a plurality of column ribs 7, one end of the column rib 7 being connected to the inner wall surface of the outer shell 1, and the other end of the column rib 7 being connected to the outer wall surface of the inner wall 2. The cooling gas entering the cooling channel 21 flows through the gaps formed between the column ribs 7. The column ribs 7 not only increase the heat exchange area, but also enhance the structural strength of the blade 100. In addition, the heat conduction effect of the column ribs 7 can also reduce the temperature difference between the inner wall 2 and the outer shell 1 to some extent, making the internal and external temperatures of the blade 100 more uniform and reducing thermal stress.

[0048] Further, the column ribs 7 are staggered in the flow direction of the cooling gas. The cooling gas entering the cooling channel 21 weaves between the column ribs 7 and changes direction after contacting the column ribs 7, thereby realizing the turbulence of the cooling gas, prolonging the flow time of the cooling gas in the cooling channel 21 and improving the cooling effect.

[0049] As an example, as shown in Figure 2 and Figure 3 , the column ribs 7 are mainly distributed on both sides of the inner wall 2, and the column ribs 7 are spaced in the vertical direction and the circumferential direction. The arrangement of the column ribs 7 further increases the heat exchange area of the cooling gas, strengthens the heat exchange capacity, and further enhances the cooling effect. In addition, due to the supporting effect of the column ribs 7, the structural strength of the blade 100 is also improved.

[0050] Optionally, the column ribs 7 are cylindrical ribs or prismatic ribs. Preferably, the column ribs 7 are prismatic ribs, for example, as shown in Figure 4 , the cross-sectional shape of the column rib 7 is rhombic. As shown in Figure 5 , the cross section of the column rib 7 is rectangular. The arrows in the figure are the flow direction of the cooling gas. Compared with the cylindrical rib, the prismatic rib has higher heat exchange capacity, so that the blade 100 provided by the embodiment of the present application has better cooling effect.

[0051] One embodiment of the present application also provides a gas turbine having the double-walled blade 100 of any one of the above embodiments.

[0052] The cooling principle and process of the blade 100 in the above embodiments will be described below according to Figure 2 and Figure 3 .

[0053] The flow path of the cooling gas in the blade 100 is specifically as shown in Figure 2 and Figure 3As shown by the arrows in the figure, a portion of the cooling gas enters the chamber of the outer casing 1 from the bottom air inlet 21, and then enters the cooling channel 21 through the through hole 22 on the inner wall 2.

[0054] Specifically, the cooling gas enters the first cooling channel 211 through the through hole on the first inner wall 201, and impingement cooling is generated on the corresponding inner wall surface of the outer casing 1. The cooling gas flows backward in the first cooling channel 211, and is sprayed out from the first air outlet slot 111 and a second air outlet slot 112, respectively. The cooling gas sprayed out from the first air outlet slot 111 forms a film cooling on the suction surface 6 of the outer casing 1, and the cooling gas sprayed out from the second air outlet slot 112 forms a film cooling on the pressure surface 5 of the outer casing 1.

[0055] The cooling gas also enters the second cooling channel through the through hole on the second inner wall 202, and impingement cooling is generated on the corresponding inner wall surface of the outer casing 1. The cooling gas flows backward in the second cooling channel, and is sprayed out from another second air outlet slot 112 located behind the second air outlet slot 112 communicating with the first cooling channel 211. The cooling gas sprayed out from the second air outlet slot 112 forms a film cooling on the pressure surface 5 of the outer casing 1.

[0056] The cooling gas also enters the third cooling channel through the through hole on the third inner wall 203, and impingement cooling is generated on the corresponding inner wall surface of the outer casing 1. The cooling gas flows backward in the third cooling channel, and is sprayed out from the third air outlet slot 113. The sprayed cooling gas plays a role of cooling the trailing edge 4.

[0057] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0058] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified.

[0059] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", "fixedly connected", "connection", "fixedly connected", "connected", "fixed", and the like should be construed broadly, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0060] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0061] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification and the features of different embodiments or examples without contradiction.

[0062] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A double wall vane for a gas turbine, characterized in that, The double-wall blade for a gas turbine comprises: a shell defining a chamber, the shell being provided with a plurality of air outlet slots extending along the length direction of the blade, the air outlet slots having openings facing the trailing edge of the shell, the blade having an air inlet communicating with the chamber; a plurality of inner walls arranged in the chamber in a circumferential direction and connected to the shell, the outer wall surface of the inner walls and the inner wall surface of the shell forming a plurality of cooling channels, the inner walls being provided with at least one through hole communicating the cooling channels and the chamber, the ends of the cooling channels close to the trailing edge of the shell communicating with the air outlet slots one by one; the air outlet slots at least include a first air outlet slot provided on the suction surface of the shell, a second air outlet slot provided on the pressure surface of the shell, and a third air outlet slot provided at the trailing edge of the shell, and the first air outlet slot and the second air outlet slot are at least one. The inner walls include at least a first inner wall opposite to the leading edge of the shell, the first inner wall and the shell forming a first cooling channel, the first cooling channel having opposite first and second ends in the extension direction thereof, the first end communicating with the first air outlet slot, and the second end communicating with the second air outlet slot.

2. The double-wall blade for a gas turbine according to claim 1, wherein the first inner wall is provided with a plurality of through holes at least at a position opposite to the leading edge.

3. The double-wall blade for a gas turbine according to claim 2, wherein the first inner wall is opposite to the leading edge, a part of the suction surface, and a part of the pressure surface, and the first inner wall is further provided with a plurality of through holes at a position opposite to the suction surface and the pressure surface.

4. The double-wall blade for a gas turbine according to any one of claims 1-3, wherein the air outlet slots have opposite first and second side walls, and the side of the inner wall close to the air outlet slots is smoothly connected to the first side wall of the air outlet slots.

5. The double-wall blade for a gas turbine according to any one of claims 1-3, wherein the cooling channels are provided with a column rib structure, the column rib structure comprising a plurality of column ribs, one end of the column ribs being connected to the shell, and the other end being connected to the inner wall.

6. The double-wall blade for a gas turbine according to claim 5, wherein the column ribs are prisms.

7. The double-wall blade for a gas turbine according to claim 5, wherein the column ribs are arranged staggered in the flow direction of the cooling air.

8. A gas turbine engine characterized by, The double-wall blade according to any one of claims 1-7.

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