Structure and method for strengthening internal cooling of stationary blades

Abstract

The present invention relates to the technical field of turbine stator blade cooling, and more particularly to a structure for enhancing internal cooling of stator blades, comprising a stator blade body connected to a stator blade platform, a cooling channel rear chamber provided within the stator blade body, a cold air inlet provided at one end of the cooling channel rear chamber remote from the stator blade platform for admitting a mainstream cooling gas, an air vent provided on the stator blade platform that communicates with the cooling channel rear chamber, the air vent used to introduce enhanced cooling gas to the end of the cooling channel rear chamber, and a trailing edge slit provided at the trailing edge of the stator blade body. The present invention also relates to a method for enhancing internal cooling of stator blades, comprising introducing the mainstream cooling gas into the cooling channel rear chamber within the stator blade body from a side of the stator blade body remote from the stator blade platform, introducing enhanced cooling gas from the bottom of the stator blade platform to the end of the cooling channel rear chamber, and the enhanced cooling gas mixing with the mainstream cooling gas and flowing out from the trailing edge slit of the stator blade. This method can prevent overheating in the trailing edge region of the stator blade body near the end of the internal cooling channel.

Description

Technical Field

[0001] The present invention relates to the technical field of turbine stator blade cooling, and in particular to a structure and method for enhancing internal cooling of a stator blade. Background Art

[0002] Gas turbine blades typically use internal cooling methods to reduce blade temperature and ensure proper service. To enhance internal heat transfer and allow the coolant to remove more heat, specific internal cooling structures are often employed.

[0003] Trailing edge slots are a common internal cooling structure for stator blades. With this internal cooling structure, cooling air enters the internal cooling channel and ultimately exits through the slots at the trailing edge of the stator blade. While flowing along the height of the stator blade within the internal cooling channel, the cooling air exits horizontally through the slots to mix with the main heat flow from the external stator blade. With this cooling structure, the trailing edge slot outlet, located at the end of the internal cooling channel, represents the final point of cooling air distribution. This area is the first to overheat if the cooling air flow decreases.

[0004] The cooling air used by the turbine stator is introduced from the gas turbine compressor. The introduction path is usually from the compressor stator ring, through the gas turbine external pipe, and finally into the internal cooling channel of the turbine stator. The cold air entering the turbine stator through this path usually contains a certain amount of impurities and dust, which needs to be filtered by the filter on the stator ring. However, as the gas turbine operates for a long time, the dust on the filter can easily cause blockage. As a result, the amount of cooling air will be reduced, and the trailing edge area of the gas turbine stator near the end of the internal cooling channel will overheat, posing a safety hazard to the normal service of the gas turbine stator. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a structure and method for strengthening the internal cooling of the stator blade, which can prevent the trailing edge area of the stator blade near the end of the internal cooling channel from overheating, thereby overcoming the above-mentioned defects of the prior art.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a structure for enhancing the internal cooling of a stator blade, comprising a stator blade body connected to a stator blade platform, a cooling channel rear chamber being provided inside the stator blade body near the trailing edge of the stator blade body, a cold air inlet being provided at one end of the cooling channel rear chamber away from the stator blade platform for introducing the mainstream of cooling gas into the cooling channel rear chamber, an air vent connected to the cooling channel rear chamber being provided on the stator blade platform, the air vent being used for introducing enhanced cooling gas into the end of the cooling channel rear chamber, and a trailing edge slit being provided at the trailing edge of the stator blade body for connecting the cooling channel rear chamber with the external space of the stator blade body.

[0008] Preferably, the vent hole extends from the bottom of the stationary blade platform to the rear chamber of the cooling channel.

[0009] Preferably, the outlet of the vent hole is connected to the rear chamber of the cooling channel on a side of the rear chamber of the cooling channel close to the trailing edge split.

[0010] Preferably, the diameter of the outlet of the vent hole is not larger than the diameter of the end of the rear chamber of the cooling channel.

[0011] Preferably, the axis of the vent hole and the axis of the cold air inlet are both perpendicular to the stationary blade platform.

[0012] Preferably, on the axial plane of the stationary blade platform, an angle α is formed between the axis of the vent hole and the stationary blade platform and satisfies: 90°<α<180°; on the radial plane of the stationary blade platform, an angle β is formed between the axis of the vent hole and the stationary blade platform and satisfies: 45°<β<135°.

[0013] Preferably, a rounded corner is provided between the inlet and the outlet of the vent hole and the stationary blade platform.

[0014] The present invention also provides a method for enhancing the internal cooling of the stator blade, wherein the mainstream cooling gas is introduced from the side of the stator blade body away from the stator blade platform into the rear chamber of the cooling channel inside the stator blade body, and the enhanced cooling gas is introduced from the bottom of the stator blade platform to the end of the rear chamber of the cooling channel. The enhanced cooling gas is mixed with the mainstream cooling gas and flows out from the trailing edge slit of the stator blade body.

[0015] Preferably, a vent hole for introducing enhanced cooling gas is opened on the stationary blade platform and extends from the bottom of the stationary blade platform to the rear chamber of the cooling channel, and the outlet of the vent hole is connected to the rear chamber of the cooling channel on the side of the rear chamber of the cooling channel close to the trailing edge split.

[0016] Compared with the prior art, the present invention has significant improvements:

[0017] The main flow of cooling gas for cooling the stator blade body is introduced into the cooling channel rear chamber inside the stator blade body from the side of the stator blade body away from the stator blade platform through the cold air inlet. The main flow of cooling gas flows along the cooling channel rear chamber toward the stator blade platform and flows out from the trailing edge slit of the stator blade body trailing edge. At the same time, a small amount of enhanced cooling gas is introduced into the end of the cooling channel rear chamber from the air vent on the stator blade platform. The flow direction of the enhanced cooling gas is opposite to the flow direction of the main flow of cooling gas. The enhanced cooling gas can be mixed with the main flow of cooling gas and flow out from the trailing edge slit of the stator blade body trailing edge together. This can supplement the cooling air volume at the end of the cooling channel rear chamber and enhance the heat exchange effect at the end of the cooling channel rear chamber, thereby enhancing the cooling effect, preventing the trailing edge area of the stator blade body near the stator blade platform from overheating, reducing the risk of overheating in the trailing edge area of the stator blade body near the cooling channel rear chamber end due to the reduction of the main flow of cooling gas after the unit has been running for a period of time, and extending the service life and service time of the stator blade. The present invention has strong feasibility and low implementation cost, and can reduce the repair and service cost of the stator blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a structure for enhancing internal cooling of a stator blade according to an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 Schematic cross-sectional view along AA direction.

[0020] Figure 3 yes Figure 1 Schematic cross-sectional view along the BB direction.

[0021] The description of the accompanying drawings is as follows:

[0022] 1 Stationary blade platform

[0023] 2 static leaf body

[0024] 20 Cooling channel rear chamber

[0025] 201 Air conditioning inlet

[0026] 202 trailing edge split

[0027] 3 vents

[0028] 31 Entrance

[0029] 32 Exit DETAILED DESCRIPTION

[0030] The following is a further detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, and are not intended to limit the present invention.

[0031] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0032] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0033] like Figures 1 to 3 As shown, an embodiment of the present invention provides a structure for enhancing the internal cooling of a stationary blade.

[0034] See also Figure 1 and Figure 2 The structure for enhancing the internal cooling of the stator blades in this embodiment includes a stator blade body 2 connected to the stator blade platform 1. A cooling channel rear chamber 20 is provided inside the stator blade body 2 near the trailing edge of the stator blade body 2. A cold air inlet 201 is provided at one end of the cooling channel rear chamber 20 away from the stator blade platform 1. The cold air inlet 201 is used to introduce a mainstream of cooling gas into the cooling channel rear chamber 20 to cool the stator blade body 2. An air vent 3 is provided on the stationary blade platform 1, and the air vent 3 is connected to the cooling channel rear chamber 20. The air vent 3 is used to introduce enhanced cooling gas into the end of the cooling channel rear chamber 20. The end of the cooling channel rear chamber 20 is the end of the cooling channel rear chamber 20 close to the stationary blade platform 1. The trailing edge of the stationary blade body 2 is provided with a trailing edge slit 202. The trailing edge slit 202 connects the cooling channel rear chamber 20 with the external space of the stationary blade body 2. The trailing edge slit 202 serves as the cold air outlet of the cooling channel rear chamber 20. The cooling gas introduced into the cooling channel rear chamber 20 flows out of the stationary blade body 2 from the trailing edge slit 202.

[0035] In the structure for enhancing the internal cooling of the stator blades of this embodiment, the main flow of cooling gas for cooling the stator blade body 2 is passed from the side of the stator blade body 2 away from the stator blade platform 1 through the cold air inlet 201 into the cooling channel rear chamber 20 inside the stator blade body 2. The main flow of cooling gas flows along the cooling channel rear chamber 20 toward the stator blade platform 1 and flows out from the trailing edge slit 202 of the trailing edge of the stator blade body 2. At the same time, a small amount of enhanced cooling gas is passed from the air vent 3 on the stator blade platform 1 into the end of the cooling channel rear chamber 20. The flow direction of the enhanced cooling gas is opposite to that of the main flow of cooling gas and can be mixed with the main flow of cooling gas. Together, the air flows out from the trailing edge slit 202 at the trailing edge of the stator blade body 2, thereby replenishing the cooling air volume at the end of the cooling channel rear chamber 20 and enhancing the heat exchange effect at the end of the cooling channel rear chamber 20, thereby enhancing the cooling effect and preventing the trailing edge area of the stator blade body 2 near the end of the cooling channel rear chamber 20 (that is, the end of the stator blade body 2 near the stator blade platform 1) from overheating. This reduces the risk of overheating at the trailing edge area of the stator blade body 2 near the end of the cooling channel rear chamber 20 due to a decrease in the mainstream flow of cooling gas after the unit has been running for a period of time, thereby extending the service life and service time of the stator blade. The structure of strengthening the internal cooling of the stator blade in this embodiment is highly feasible and has low implementation cost, which can reduce the repair and service costs of the stator blade.

[0036] See also Figure 1 and Figure 3 In this embodiment, the vent 3 preferably extends from the bottom of the stationary blade platform 1 to the cooling channel rear chamber 20. The bottom of the stationary blade platform 1 refers to the side of the stationary blade platform 1 away from the stationary blade body 2, and is also the cold side of the stationary blade platform 1. Therefore, the inlet 31 of the vent 3 is located on the bottom surface of the stationary blade platform 1 (the side of the stationary blade platform 1 away from the stationary blade body 2), and the outlet 32 of the vent 3 is located on the top surface of the stationary blade platform 1 (the side of the stationary blade platform 1 close to the stationary blade body 2).

[0037] In this embodiment, preferably, the outlet 32 of the vent hole 3 is connected to the cooling channel rear chamber 20 on a side of the cooling channel rear chamber 20 near the trailing edge slit 202. This ensures that the enhanced cooling gas entering the end of the cooling channel rear chamber 20 from the vent hole 3 can effectively cool the trailing edge area of the stationary blade 2 near the end of the cooling channel rear chamber 20.

[0038] In this embodiment, preferably, the diameter of the outlet 32 of the vent hole 3 is not larger than the diameter of the end of the cooling channel rear chamber 20 to ensure that the enhanced cooling gas entering the vent hole 3 can all enter the end of the cooling channel rear chamber 20.

[0039] See also Figure 1In this embodiment, preferably, the axis of the vent hole 3 and the axis of the cold air inlet 201 are both perpendicular to the stationary blade platform 1, so that the flow direction of the enhanced cooling gas in the rear chamber 20 of the cooling channel is opposite to the flow direction of the mainstream cooling gas along the blade height direction of the stationary blade body 2, which can achieve the best mixing effect. Figure 1 The middle arrow shows the flow direction of the enhanced cooling gas and the mainstream of the cooling gas. The mainstream of the cooling gas enters the rear chamber 20 of the cooling channel from the cold air inlet 201. The mainstream of the cooling gas flows along the blade height direction of the stator blade body 2 toward the stator blade platform 1 in the rear chamber 20 of the cooling channel, and at the same time flows out horizontally from the trailing edge slit 202 of the trailing edge of the stator blade body 2; the enhanced cooling gas enters the end of the rear chamber 20 of the cooling channel from the air vent 3, mixes with the mainstream of the cooling gas, and flows out horizontally from the trailing edge slit 202 of the trailing edge of the stator blade body 2.

[0040] Of course, the axis of the vent hole 3 and the stationary blade platform 1 may also form an angle. Figure 1 and Figure 3 , Figure 1 The drawing paper is the axial plane of the stationary blade platform 1. Figure 3 The drawing paper is a radial plane of the stator blade platform 1. Preferably, on the axial plane of the stator blade platform 1, an angle α is formed between the axis of the vent hole 3 and the stator blade platform 1 and satisfies: 90°<α<180°; on the radial plane of the stator blade platform 1, an angle β is formed between the axis of the vent hole 3 and the stator blade platform 1 and satisfies: 45°<β<135°.

[0041] In this embodiment, preferably, both the inlet 31 and the outlet 32 of the vent hole 3 are provided with rounded corners between the stationary blade platform 1 to reduce the flow resistance of the cooling gas.

[0042] The embodiment of the present invention also provides a method for strengthening the internal cooling of the stationary blade. Figures 1 to 3 As shown, the method for enhancing internal cooling of the stator blades of this embodiment is to introduce a main stream of cooling gas into the cooling channel rear chamber 20 inside the stator blade 2 from the side of the stator blade body 2 away from the stator blade platform 1. Enhanced cooling gas is then introduced from the bottom of the stator blade platform 1 to the end of the cooling channel rear chamber 20. The enhanced cooling gas is mixed with the main stream of cooling gas and then flows out through the trailing edge slit 202 of the stator blade 2. This replenishes the cooling air volume at the end of the cooling channel rear chamber 20 and enhances the heat exchange effect at the end of the cooling channel rear chamber 20, thereby enhancing the cooling effect and preventing overheating in the trailing edge region of the stator blade 2 near the end of the cooling channel rear chamber 20 (i.e., the end of the stator blade 2 near the stator blade platform 1). This reduces the risk of overheating in the trailing edge region of the stator blade 2 near the end of the cooling channel rear chamber 20 due to a decrease in the main stream of cooling gas flow after a period of unit operation, thereby extending the service life and service life of the stator blade 2. The method for enhancing internal cooling of the stator blades of this embodiment is highly feasible and cost-effective, and can reduce the repair and service costs of the stator blade 2.

[0043] In the method for enhancing internal cooling of a stator blade of this embodiment, preferably, a vent hole 3 for admitting enhanced cooling gas can be provided on the stator blade platform 1, extending from the bottom of the stator blade platform 1 to the cooling channel rear chamber 20. The outlet 32 of the vent hole 3 is connected to the cooling channel rear chamber 20 on a side of the cooling channel rear chamber 20 near the trailing edge slit 202. This ensures that the enhanced cooling gas entering the end of the cooling channel rear chamber 20 through the vent hole 3 can effectively cool the trailing edge region of the stator blade body 2 near the end of the cooling channel rear chamber 20.

[0044] The method of enhancing the internal cooling of the stator blades in this embodiment can be achieved by the structure of enhancing the internal cooling of the stator blades of the present invention.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A structure for strengthening internal cooling of a stator blade, comprising a stator blade body (2) connected to a stator blade platform (1), characterized in that: A cooling channel rear chamber (20) is provided inside the stationary blade body (2) near the trailing edge of the stationary blade body (2); a cold air inlet (201) is provided at one end of the cooling channel rear chamber (20) away from the stationary blade platform (1) for introducing the main flow of cooling gas into the cooling channel rear chamber (20); an air vent (3) is provided on the stationary blade platform (1) and is connected to the cooling channel rear chamber (20); the air vent (3) is used to introduce enhanced cooling gas into the end of the cooling channel rear chamber (20); the trailing edge of the stationary blade body (2) A trailing edge slit (202) is provided for connecting the cooling channel rear chamber (20) and the external space of the stationary blade body (2); an outlet (32) of the vent hole (3) is connected to the cooling channel rear chamber (20) on a side of the cooling channel rear chamber (20) close to the trailing edge slit (202); the position of the outlet (32) of the vent hole (3) is closer to the trailing edge slit (202) relative to the position of the cold air inlet (201); and the diameter of the outlet (32) of the vent hole (3) is smaller than the diameter of the cold air inlet (201).

2. The structure for enhancing internal cooling of a stator blade according to claim 1, characterized in that: The vent hole (3) extends from the bottom of the stationary blade platform (1) to the cooling channel rear chamber (20).

3. The structure for enhancing internal cooling of a stator blade according to claim 1, characterized in that: The diameter of the outlet (32) of the vent hole (3) is not greater than the diameter of the end of the cooling channel rear chamber (20).

4. The structure for enhancing internal cooling of a stator blade according to claim 1, characterized in that: The axis of the vent hole (3) and the axis of the cold air inlet (201) are both perpendicular to the stationary blade platform (1).

5. The structure for enhancing internal cooling of a stator blade according to claim 1, characterized in that: On the axial plane of the stationary blade platform (1), an angle α is formed between the axis of the vent hole (3) and the stationary blade platform (1) and satisfies the following conditions: 90°<α<180°; on the radial plane of the stationary blade platform (1), an angle β is formed between the axis of the vent hole (3) and the stationary blade platform (1) and satisfies the following conditions: 45°<β<135°.

6. The structure for enhancing internal cooling of a stator blade according to claim 1, characterized in that: The inlet (31) and the outlet (32) of the vent hole (3) are both provided with rounded corners between themselves and the stationary blade platform (1).

7. A method for strengthening the internal cooling of a stationary blade, characterized in that: A main stream of cooling gas is introduced from a side of the stationary blade body (2) away from the stationary blade platform (1) into a cooling channel rear chamber (20) inside the stationary blade body (2); an end of the cooling channel rear chamber (20) away from the stationary blade platform (1) is provided with a cold air inlet (201) for introducing the main stream of cooling gas into the cooling channel rear chamber (20); enhanced cooling gas is introduced from the bottom of the stationary blade platform (1) to the end of the cooling channel rear chamber (20); the enhanced cooling gas is mixed with the main stream of cooling gas and then flows out from the trailing edge slit (202) of the stationary blade body (2) and flows into the stationary blade platform (1). An air vent (3) for introducing the enhanced cooling gas is provided on the cooling channel, extending from the bottom of the stationary blade platform (1) to the rear chamber (20) of the cooling channel, and an outlet (32) of the air vent (3) is connected to the rear chamber (20) of the cooling channel on a side of the rear chamber (20) of the cooling channel close to the trailing edge slit (202). The position of the outlet (32) of the air vent (3) is closer to the trailing edge slit (202) relative to the position of the cold air inlet (201), and the diameter of the outlet (32) of the air vent (3) is smaller than the diameter of the cold air inlet (201).

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