Turbine stator blade of gas turbine and gas turbine using the same

Abstract

A gas turbine turbine stator blade and a gas turbine using the same, wherein the turbine stator blade comprises a blade body and end walls located at both ends of the blade body; the outer surface of the blade body is composed of a suction surface and a pressure surface, and the interface area between the suction surface and the pressure surface is the blade leading edge and the blade trailing edge respectively; the end wall portion corresponding to the blade trailing edge is defined as the end wall trailing edge; wherein the end wall trailing edge is provided with an end wall trailing edge cavity, and the end wall trailing edge cavity is provided with at least one cooling air through hole in the corresponding end wall trailing edge area. The present invention provides an end wall trailing edge cavity in the end wall trailing edge area, and reduces the temperature and stress level of the turbine stator blade end wall trailing edge area without increasing the amount of cooling air.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine design, and in particular to a turbine stator blade of a gas turbine and a gas turbine using the same. Background Art

[0002] With the improvement of gas turbine design technology, the temperature of gas at the inlet of gas turbine turbine is increasing, and the thermal load faced by turbine components is extremely high, which has long exceeded the limit that high-temperature materials can withstand. In order to ensure the safe and reliable operation of turbine blades, complex cooling design is required to keep the temperature and stress distribution of the blade body at a reasonable level.

[0003] In order to meet the increasing environmental protection requirements, the gas turbine combustion system generally adopts DLN low-nitrogen combustion technology, which makes the gas turbine inlet temperature profile flatter - that is, it reduces the peak temperature of the gas turbine inlet, but increases the temperature level of the end wall area. Therefore, in the low-nitrogen combustion gas turbine turbine, the difficulty of end wall design is further increased, and the cooling arrangement of the trailing edge area of ​​the turbine stator blade end wall is difficult, which is very prone to cracks, high-temperature oxidation, and even ablation. Summary of the invention

[0004] In view of this, the main object of the present invention is to provide a turbine stator blade of a gas turbine and a gas turbine using the same, in order to at least partially solve at least one of the above-mentioned technical problems.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] As one aspect of the present invention, a turbine stator blade of a gas turbine is provided, comprising a blade body and end walls located at both ends of the blade body; the outer surface of the blade body is composed of a suction surface and a pressure surface, and the junction area of ​​the suction surface and the pressure surface is respectively a blade leading edge and a blade trailing edge; the end wall portion corresponding to the blade trailing edge is defined as an end wall trailing edge;

[0007] Wherein, the end wall trailing edge is provided with an end wall trailing edge cavity, and the end wall trailing edge cavity is provided with at least one cold air through hole in a region corresponding to the end wall trailing edge.

[0008] As another aspect of the present invention, a gas turbine is provided, which uses the turbine stator blades as described above.

[0009] Based on the above technical solution, it can be known that the present invention has at least one or part of the following beneficial effects compared with the prior art:

[0010] (1) The present invention provides an end wall trailing edge cavity in the end wall trailing edge region, thereby reducing the temperature and stress level in the end wall trailing edge region of the turbine stator blade without increasing the amount of cooling air;

[0011] (2) The air intake arrangement of the end wall trailing edge cavity of the present invention is varied, the cooling air acquisition method is flexible, and it is easy to implement and apply;

[0012] (3) A serpentine channel is arranged in the cavity at the trailing edge of the end wall to form convection cooling of multiple continuous cooling channels, which can further reduce the temperature, temperature gradient and stress level in the trailing edge area of ​​the end wall;

[0013] (4) Cooling enhancement structures, such as protrusions of various shapes and spoiler columns, are arranged in the cavity at the trailing edge of the end wall to further enhance the cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of a turbine stator blade of a gas turbine of Comparative Example 1;

[0015] Figure 2 yes Figure 1 AA section diagram of ;

[0016] Figure 3 is a schematic diagram of a turbine stator blade of a gas turbine according to Embodiment 1 of the present invention;

[0017] Figure 4 yes Figure 3 BB section schematic diagram;

[0018] Figure 5 is a schematic diagram of a turbine stator blade of a gas turbine according to Embodiment 2 of the present invention;

[0019] Figure 6 yes Figure 5 Schematic diagram of the CC section;

[0020] Figure 7 is a schematic diagram of a turbine stator blade of a gas turbine according to Embodiment 3 of the present invention;

[0021] Figure 8 yes Figure 7 Schematic diagram of the DD section.

[0022] In the above drawings, the meanings of the reference numerals are as follows:

[0023] 1-blade blade body; 2-upper end wall; 3-lower end wall; 4-impact bushing; 5-first impact cooling cover plate; 6-second impact cooling cover plate; 7-lower end wall guide rail; 8-upper end wall guide rail; 9-first cold air injection hole; 10-second cold air injection hole; 11-blade leading edge; 12-blade trailing edge; 13-first hook; 14-second hook; 15-support ring; 16-end wall trailing edge high temperature zone; 17-upper end wall impact cavity; 18-lower end wall impact cavity; 19-blade internal impact cavity; 201, 202, 203-lower end wall trailing edge cavity entrance; 21-lower end wall trailing edge cavity; 22-lower end wall trailing edge cavity cover plate; 23-lower end wall trailing edge cavity through hole; 24-partition; 25-first cooling channel; 26-second cooling channel; 27-third cooling channel. DETAILED DESCRIPTION

[0024] The present invention designs cooling of the trailing edge end wall region of a turbine stator blade without increasing the total cooling air volume, so as to reduce the temperature and stress level of the trailing edge region of the end wall of the turbine stator blade.

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0026] As one aspect of the present invention, a turbine stator blade of a gas turbine is provided, comprising a blade body and end walls located at both ends of the blade body; the outer surface of the blade body is composed of a suction surface and a pressure surface, and the junction area between the suction surface and the pressure surface is respectively a blade leading edge and a blade trailing edge; the end wall portion corresponding to the blade trailing edge is defined as an end wall trailing edge;

[0027] Wherein, the end wall trailing edge is provided with an end wall trailing edge cavity, and the end wall trailing edge cavity is provided with at least one cold air through hole in a region corresponding to the end wall trailing edge.

[0028] In the embodiment of the present invention, the cross-sectional shape of the cooling air through hole includes but is not limited to a circle, an ellipse, a square or a diamond; as long as the circulation cooling effect can be achieved.

[0029] In the embodiment of the present invention, the cooling air through hole can be formed by, but is not limited to, casting, electrical machining or laser machining.

[0030] In an embodiment of the present invention, the extension direction of the cold air through hole is parallel to the wall surface of the end wall; the cold air through hole includes a plurality of holes arranged in an array.

[0031] More specifically, the number, shape, size and arrangement of the cooling air holes can be determined according to the actual available amount of cooling air and the cooling design requirements of the end wall trailing edge region.

[0032] In an embodiment of the present invention, air cooling is adopted inside the blade body, and the cooling air in the cavity at the trailing edge of the end wall comes from the air after the inside of the blade body is cooled, and the air after the inside of the blade body is cooled is defined as the blade body cooling air exhaust air;

[0033] An end wall trailing edge cavity inlet is arranged on the end wall trailing edge, the end wall trailing edge cavity inlet is connected to the end wall trailing edge cavity and the interior of the blade body, and the blade body cooling air exhaust enters the end wall trailing edge cavity through the end wall trailing edge cavity inlet.

[0034] More specifically, an impact bushing is arranged inside the blade body, and the space between the impact bushing and the blade body is defined as the internal impact cavity of the blade; after the cooling air enters the impact bushing, the blade body is impact-cooled, and the blade body cooling air exhaust after impact cooling is in the internal impact cavity of the blade. The end wall trailing edge cavity inlet connects the end wall trailing edge cavity and the blade internal impact cavity, so that the blade body cooling air exhaust in the internal impact cavity of the blade enters the end wall trailing edge cavity.

[0035] In an embodiment of the present invention, the blade airfoil may include one or more impingement bushings inside, and the impingement bushings adopt impingement cooling. The blade airfoil cooling air exhaust in the lower end wall trailing edge cavity may come from one or more impingement bushings of the blade airfoil.

[0036] In another embodiment of the present invention, the end wall portion corresponding to the leading edge of the blade is defined as the leading edge of the end wall; an end wall impact cavity is provided at the leading edge of the end wall; the cooling air in the cavity at the trailing edge of the end wall comes from the end wall impact cooling air exhaust air in the end wall impact cavity;

[0037] An end wall guide rail is arranged on the end wall, and a first through hole is arranged on the end wall guide rail, and the end wall impact cooling air exhaust gas enters the end wall trailing edge cavity through the first through hole of the end wall guide rail. The first through hole becomes another arrangement mode of the end wall impact cavity inlet on the end wall impact cavity, thereby providing another cooling air source for cooling the end wall impact cavity.

[0038] In another embodiment of the present invention, an end wall guide rail is provided on the end wall, and a second through hole is provided on the end wall guide rail, and the exhaust gas of the compressor enters the end wall trailing edge cavity through the second through hole of the end wall guide rail. The second through hole becomes another arrangement mode of the end wall impact cavity inlet on the end wall impact cavity, thereby providing another cooling air source for cooling the end wall impact cavity.

[0039] In an embodiment of the present invention, the end wall trailing edge cavity is disposed on the upper end wall and / or the lower end wall. More specifically, the end wall trailing edge cavity is not limited to being disposed on the lower end wall, but may also be disposed on the upper end wall or on both the upper end wall and the lower end wall.

[0040] In an embodiment of the present invention, a partition is arranged inside the cavity at the trailing edge of the end wall, so that a serpentine channel is formed inside the cavity at the trailing edge of the end wall.

[0041] In the embodiments of the present invention, on the one hand, the serpentine passage can improve the cooling effect; on the other hand, the serpentine passage can also limit the gas flow direction of the cooling air in the cavity at the trailing edge of the end wall.

[0042] It is worth mentioning that the shape and size of the serpentine channel can be determined according to the cooling design requirements. The shape of the serpentine channel can be any polygon, and the flow area can be changed according to actual needs.

[0043] In an embodiment of the present invention, a protrusion and / or a spoiler column for enhancing cooling is arranged in the cavity at the trailing edge of the end wall.

[0044] In an embodiment of the present invention, the end wall trailing edge cavity is formed by integrally casting the end wall and the end wall trailing edge cavity cover plate; or, the end wall trailing edge cavity is formed by welding and sealing the end wall and the end wall trailing edge cavity cover plate.

[0045] In an embodiment of the present invention, the blade airfoil of the turbine stator blade is a single independent casting structure; or the blade airfoil of the turbine stator blade is a plurality of integral casting structures arranged at intervals.

[0046] As one aspect of the present invention, there is also provided a gas turbine which employs the turbine stator blades as described above.

[0047] The technical solution of the present invention is further described below in conjunction with specific embodiments and comparative examples. However, it should be noted that the following embodiments are only used to illustrate the technical solution of the present invention, but the present invention is not limited thereto.

[0048] Comparative Example 1

[0049] like Figure 1 and Figure 2 As shown, this comparative example 1 provides a high-temperature turbine stator blade of a gas turbine. The high-temperature turbine stator blade structure of the gas turbine is as shown in Examples 1 to 3, including a blade blade body 1, an upper end wall 2, a lower end wall 3, an upper end wall guide rail 8, a lower end wall guide rail 7, a first impingement cooling cover plate 5, a second impingement cooling cover plate 6 and an impingement bushing 4. The turbine stator blade is matched with the upper end wall guide rail 8 and fixed to the combustion engine body through the first hook 13 and the second hook 14, and the support ring 15 is matched with the lower end wall guide rail 7 and fixes the turbine stator blade assembly on the support ring 15.

[0050] The cooling air cools the upper end wall 2 through the first impingement cooling cover plate 5 of the upper end wall 2, and then enters the interior of the impingement bushing 4 through the upper end wall impingement cavity 17, and impinges and cools the blade blade 1. The exhaust gas after impingement cooling enters the mainstream combustion gas through the first cold air injection hole 9 in the impingement cavity 19 inside the blade. The cooling air of the lower end wall 3 cools the lower end wall 3 through the second impingement cooling cover plate 6, and then enters the combustion gas side of the lower end wall 3 through the second cold air injection hole 10 on the wall surface of the lower end wall impingement cavity 18.

[0051] Among them, the difference between the turbine stator blade structure of the gas turbine provided in the comparative example 1 and the turbine stator blade structure of the embodiments 1 to 3 is that the end wall trailing edge high temperature zone 16 is formed on the upper end wall and / or lower end wall of the turbine stator blade. This is because: the pressure on the cold air side is low at the rear of the lower end wall guide rail 7 of the lower end wall 3, and the pressure on the cold air side is also low at the rear of the upper end wall guide rail 8 of the upper end wall 2, so it is impossible to arrange the impingement cooling, and the gas side is not significantly covered by the air film of the cold air injection hole 10; thus, the end wall trailing edge high temperature zone 16 appears. This defect will cause the end wall trailing edge high temperature zone 16 to have problems such as ablation, oxidation, and cracks.

[0052] Example 1

[0053] Figure 3 is a schematic structural diagram of a turbine stator blade of a gas turbine according to Embodiment 1 of the present invention, Figure 4 yes Figure 3 BB view. Figure 3 and Figure 4 As shown, the turbine stator blade of the gas turbine includes a blade body 1, an upper end wall 2, a lower end wall 3, an upper end wall guide rail 8, a lower end wall guide rail 7, a first impingement cooling cover plate 5, a second impingement cooling cover plate 6 and an impingement bushing 4. The turbine stator blade is matched with the upper end wall guide rail 8 and fixed to the engine body through the first hook 13 and the second hook 14, and the support ring 15 is matched with the lower end wall guide rail 7 and fixes the high-temperature stator blade assembly on the support ring 15.

[0054] The cooling air cools the upper end wall 2 through the first impingement cooling cover plate 5 of the upper end wall 2, and then enters the interior of the impingement bushing 4 through the upper end wall impingement cavity 17, and impinges and cools the blade blade 1. The exhaust gas after impingement cooling enters the mainstream combustion gas through the first cold air injection hole 9 in the impingement cavity 19 inside the blade. The cooling air of the lower end wall 3 cools the lower end wall 3 through the second impingement cooling cover plate 6, and then enters the combustion gas side of the lower end wall 3 through the second cold air injection hole 10 on the wall surface of the lower end wall impingement cavity 18.

[0055] The turbine stator blade provided in Example 1 of the present invention is provided with a lower end wall trailing edge cavity 21 in the end wall trailing edge high temperature zone 16, and the lower end wall trailing edge cavity 21 is formed by fixing a lower end wall trailing edge cavity cover plate 22 on the lower end portion 3 to seal, and the cooling air of the lower end wall trailing edge cavity 21 comes from the blade blade cooling air exhaust air of the internal impact cavity 19 of the blade, and enters the lower end wall trailing edge cavity 21 through the lower end wall trailing edge cavity inlet 201. The cooling air in the lower end wall trailing edge cavity 21 cools the end wall trailing edge high temperature zone 16 of the lower end wall 3 through the lower end wall trailing edge cavity through hole 23, thereby effectively reducing the temperature of this area, and significantly alleviating the problems of ablation, oxidation, cracks, etc. caused by high temperature.

[0056] Example 2

[0057] Figure 5 is a schematic structural diagram of a turbine stator blade of a gas turbine provided in Example 2 of the present invention, Figure 6 yes Figure 5 CC section view. Figure 5 and Figure 6 As shown, the structure of the embodiment 2 of the present invention is different from that of the embodiment 1 of the present invention in that: a lower end wall trailing edge cavity 21 is provided in the end wall trailing edge high temperature zone 16, and the lower end wall trailing edge cavity 21 is formed by fixing a lower end wall trailing edge cavity cover plate 22 on the lower end wall 3 and sealing, and the cooling air of the lower end wall trailing edge cavity 21 comes from the end wall impact cooling air exhaust gas of the lower end wall impact cavity 18 of the lower end wall 3, and enters the lower end wall trailing edge cavity 21 through the lower end wall trailing edge cavity inlet 202 (i.e., the first through hole). The cooling air in the lower end wall trailing edge cavity 21 cools the end wall trailing edge high temperature zone 16 of the lower end wall 3 through the lower end wall trailing edge cavity through hole 23, thereby effectively reducing the temperature of this area, and significantly alleviating the problems of ablation, oxidation, cracks, etc. caused by high temperature.

[0058] Example 3

[0059] Figure 7 is a schematic structural diagram of a turbine stator blade of a gas turbine provided in Example 3 of the present invention, Figure 8 yes Figure 7 DD section view. Figure 7 and Figure 8 As shown, the structure of the embodiment 3 of the present invention is different from that of the embodiment 1 of the present invention in that:

[0060] An upper end wall trailing edge cavity and a lower end wall trailing edge cavity 21 are provided in the high temperature zone 16 of the end wall trailing edge. The lower end wall trailing edge cavity 21 is formed by fixing a lower end wall trailing edge cavity cover plate 22 on the lower end wall 3 and sealing. The cooling air of the lower end wall trailing edge cavity 21 comes from the exhaust of the compressor and enters the lower end wall trailing edge cavity 21 through the lower end wall trailing edge cavity inlet 203 (i.e., the second through hole). The lower end wall trailing edge cavity 21 is divided into serpentine channels by a partition 24, including a first cooling channel 25, a second cooling channel 26, and a third cooling channel 27. The cooling air performs uniform convection cooling on the end wall area along the above-mentioned serpentine channels. The cooling air in the lower end wall trailing edge cavity 21 further cools the high temperature zone 16 of the end wall trailing edge through the lower end wall trailing edge cavity through hole 23.

[0061] Through the above cooling design, the temperature level in the trailing edge area of ​​the end wall can be effectively reduced, the temperature gradient level can be reduced, and problems such as ablation, oxidation, and cracks caused by high temperature can be significantly alleviated.

[0062] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A turbine stator blade of a gas turbine, characterized in that: It includes a blade body and end walls at both ends of the blade body; the outer surface of the blade body is composed of a suction surface and a pressure surface, and the intersection area of ​​the suction surface and the pressure surface is the leading edge of the blade and the trailing edge of the blade respectively; the end wall portion corresponding to the trailing edge of the blade is defined as the trailing edge of the end wall; Wherein, the end wall trailing edge is provided with an end wall trailing edge cavity, and the end wall trailing edge cavity is provided with at least one cold air through hole in the corresponding end wall trailing edge area; The cooling air in the end wall trailing edge cavity cools the end wall trailing edge region through the at least one cooling air through hole in the end wall trailing edge cavity; The blade body is cooled by air, and the cooling air in the end wall trailing edge cavity comes from the air after the blade body is cooled, and the air after the blade body is cooled is defined as the blade body cooling air exhaust air; An end wall trailing edge cavity inlet is arranged on the end wall trailing edge, the end wall trailing edge cavity inlet connects the end wall trailing edge cavity and the interior of the blade body, and the blade body cooling air exhaust enters the end wall trailing edge cavity through the end wall trailing edge cavity inlet.

2. A turbine stator blade of a gas turbine, characterized in that: It includes a blade body and end walls at both ends of the blade body; the outer surface of the blade body is composed of a suction surface and a pressure surface, and the intersection area of ​​the suction surface and the pressure surface is the leading edge of the blade and the trailing edge of the blade respectively; the end wall portion corresponding to the trailing edge of the blade is defined as the trailing edge of the end wall; Wherein, the end wall trailing edge is provided with an end wall trailing edge cavity, and the end wall trailing edge cavity is provided with at least one cold air through hole in the corresponding end wall trailing edge area; The cooling air in the end wall trailing edge cavity cools the end wall trailing edge region through the at least one cooling air through hole in the end wall trailing edge cavity; The end wall portion corresponding to the leading edge of the blade is defined as the leading edge of the end wall; an end wall impact cavity is arranged at the leading edge of the end wall; the cooling air in the cavity at the trailing edge of the end wall comes from the end wall impact cooling air exhaust air in the end wall impact cavity; An end wall guide rail is arranged on the end wall, and a first through hole is arranged on the end wall guide rail. Exhaust air of the end wall impact cooling air enters the end wall trailing edge cavity through the first through hole of the end wall guide rail.

3. A turbine stator blade of a gas turbine, characterized in that: It includes a blade body and end walls at both ends of the blade body; the outer surface of the blade body is composed of a suction surface and a pressure surface, and the intersection area of ​​the suction surface and the pressure surface is the leading edge of the blade and the trailing edge of the blade respectively; the end wall portion corresponding to the trailing edge of the blade is defined as the trailing edge of the end wall; Wherein, the end wall trailing edge is provided with an end wall trailing edge cavity, and the end wall trailing edge cavity is provided with at least one cold air through hole in the corresponding end wall trailing edge area; The cooling air in the end wall trailing edge cavity cools the end wall trailing edge region through the at least one cooling air through hole in the end wall trailing edge cavity; An end wall guide rail is arranged on the end wall, and a second through hole is arranged on the end wall guide rail. The exhaust gas of the compressor enters the end wall trailing edge cavity through the second through hole of the end wall guide rail.

4. The turbine stator blade according to any one of claims 1 to 3, characterized in that: The end wall trailing edge cavity is arranged on the upper end wall and / or the lower end wall.

5. The turbine stator blade according to any one of claims 1 to 3, characterized in that: A partition is arranged inside the cavity at the trailing edge of the end wall, so that a serpentine channel is formed inside the cavity at the trailing edge of the end wall.

6. The turbine stator blade according to any one of claims 1 to 3, characterized in that: A protrusion and / or a spoiler column for enhancing cooling is arranged in the cavity at the trailing edge of the end wall.

7. The turbine stator blade according to any one of claims 1 to 3, characterized in that: The cross-sectional shape of the cooling air through hole includes circular, elliptical, square or diamond; The cooling air through hole is formed by casting, electrical machining or laser machining.

8. The turbine stator blade according to any one of claims 1 to 3, characterized in that: The end wall trailing edge cavity is formed by integrally casting the end wall and the end wall trailing edge cavity cover plate; or, The end wall trailing edge cavity is formed by welding and sealing the end wall and the end wall trailing edge cavity cover plate.

9. A gas turbine, characterized in that: A turbine stator blade as claimed in any one of claims 1 to 8 is used.

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