Turbine blade, gas turbine and gas turbine generator set

Abstract

The present application relates to the technical field of gas turbine turbine blades, and particularly relates to a turbine blade, a gas turbine turbine and a gas turbine generator set. The turbine blade comprises: a blade body comprising a pressure side wall and a suction side wall, the pressure side wall and the suction side wall are both arc-shaped, a partition plate is connected between the pressure side wall and the suction side wall, the partition plate, the pressure side wall and the suction side wall enclose a groove-shaped blade tip at an end of the blade body; a flow blocking piece is installed on the partition plate, one end of the flow blocking piece is connected with the pressure side wall, and the other end of the flow blocking piece is separately arranged from the suction side wall; and a film cooling hole is arranged through the partition plate, and the film cooling hole is arranged downstream of the flow blocking piece. The flow directions of the two parts of cold air are separated by arranging the flow blocking piece, so that the two parts of cold air flow without interference, the repeated area generated by the coverage of the two parts of cold air is reduced or even eliminated, and the cooling efficiency of the cold air resource can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbine turbine blade, and particularly relates to a turbine blade, a gas turbine turbine and a gas turbine generator set. BACKGROUND

[0002] Modern gas turbine parameters are gradually improved, and the initial temperature of a new type of "H" grade gas turbine turbine reaches above 1500 DEG C. Under the impact of high-temperature and high-pressure gas, a large amount of thermal load is formed on the surface of each component of the turbine, which seriously endangers the safe use of the component material. The first stage turbine blade tip is exposed to a high-temperature and high-pressure environment for a long time, and is a vulnerable turbine component.

[0003] The gas turbine turbine is located downstream of the combustion chamber and is composed of a plurality of turbine stages. Each turbine stage is composed of a plurality of static blades and turbine blades. The turbine blades are located downstream of the static blades, and the upper and lower sides of the static blades and the turbine blades are respectively the end wall and the casing. The end wall is divided into two parts: the static blade end wall connected with the static blade, and the turbine blade end wall connected with the turbine blade. The region of the turbine blade close to the casing is called the blade tip, and the radial gap between the blade tip and the casing is called the blade tip gap. In order to drive the turbine blade to work, there is a pressure gradient on both sides of the turbine blade tip, which drives the main flow of the gas in the cascade channel to pass through the blade tip gap to form a blade tip gap leakage flow, causing blade tip leakage loss, thereby reducing the work efficiency of the gas turbine. In order to reduce the blade tip gap leakage loss, the turbine blade of the modern gas turbine is often provided with a groove-shaped blade tip: the groove-shaped blade tip is improved and optimized on the basis of the traditional flat blade tip, and specifically includes a middle groove, a pressure side shoulder wall and a suction side shoulder wall. The middle groove, the pressure side shoulder wall and the suction side shoulder wall form a kind of labyrinth seal structure, and the pressure side shoulder wall and the suction side shoulder wall are similar to the action of the sealing teeth in the labyrinth seal. The blade tip gap leakage flow forms a vortex in the blade tip groove, increases the dissipation, and the flow of the blade tip gap leakage flow is reduced.

[0004] In order to prevent the impact of high-temperature gas on each component of the turbine, the gas turbine in the prior art adopts the method of extracting air for cooling and setting a cooling slot structure on the casing upstream of the blade tip of the turbine to cool and protect the turbine components. The method of extracting air for cooling is specifically extracting air from different positions of the compressor of the gas turbine, sending the air to the inside of each component of the turbine through the internal passage of the gas turbine, and then flowing out through the slot between the components and the gas film cooling hole on the surface of the component to form a cold gas film on the surface of the component to protect the surface of the component from being eroded by high-temperature gas. For the concave groove-shaped blade tip, the surface of the blade tip of the turbine is generally cooled by the gas film cooling hole. This structure sets a certain number of gas film cooling holes at the flow separation line position on the bottom surface of the blade tip groove. After the cold gas flows out of the gas film cooling hole, the cold gas flows to both sides to cover the blade tip wall. In the structure of setting a cooling slot on the casing upstream of the blade tip of the turbine, the cold gas enters the gap between the blade tips from the leading edge of the blade tip after leaving the cooling slot. At this time, the cold gas will cool the front half of the blade tip. In this way, the cold gas coverage range of the casing slot cooling and the blade tip gas film cooling hole will overlap, causing waste of cold gas resources. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to overcome the defects in the prior art that the cold gas coverage range of the cooling slot structure set on the casing upstream of the blade tip of the turbine and the original gas film cooling hole on the surface of the blade tip of the turbine overlaps, causing waste of cold gas resources, so as to provide a turbine blade, a gas turbine turbine and a gas turbine generator set.

[0006] In order to solve the above technical problems, the present application provides a turbine blade, comprising:

[0007] a blade body comprising a pressure side wall and a suction side wall, the pressure side wall and the suction side wall are arc-shaped, and a partition plate is connected between the pressure side wall and the suction side wall, the partition plate, the pressure side wall and the suction side wall form a concave groove-shaped blade tip at the end of the blade body;

[0008] a flow blocking piece installed on the partition plate, one end of the flow blocking piece being connected with the pressure side wall and the other end of the flow blocking piece being separated from the suction side wall;

[0009] a gas film cooling hole penetrating through the partition plate, the gas film cooling hole being arranged downstream of the flow blocking piece.

[0010] Optionally, the flow blocking piece is arranged vertically to the pressure side wall.

[0011] Optionally, the length of the flow blocking piece is 40% to 60% of the width of the groove at the installation position of the flow blocking piece.

[0012] Optionally, the baffle bottom is connected with the isolation plate, the baffle top is flush with the pressure side wall, and the height of the baffle is 1% to 3% of the height of the blade body.

[0013] The application further provides a gas turbine generator set with the turbine blade.

[0014] Optionally, the turbine blade is installed in a casing, the casing is further provided with a turbine vane, the turbine vane is installed upstream of the turbine blade, the casing is provided with a slot cooling port, the slot cooling port is directed towards the turbine vane and the turbine blade, and the slot cooling port is obliquely arranged towards the turbine blade.

[0015] Optionally, a baffle is arranged at the outlet end of the slot cooling port, close to one side of the turbine vane, and the baffle extends away from the slot cooling port.

[0016] Optionally, the height of the baffle is 1% to 3% of the height of the blade body of the turbine blade.

[0017] Optionally, the included angle between the slot cooling port and the top surface of the turbine blade is 15° to 75°.

[0018] The application further provides a gas turbine generator set with the turbine blade.

[0019] The technical scheme of the application has the following advantages:

[0020] 1. The turbine blade provided by the application comprises: a blade body comprising a pressure side wall and a suction side wall, both the pressure side wall and the suction side wall being arc-shaped, and an isolation plate being connected between the pressure side wall and the suction side wall, the isolation plate, the pressure side wall and the suction side wall surrounding a concave slot-shaped blade tip at the end of the blade body; a baffle being installed on the isolation plate, one end of the baffle being connected with the pressure side wall and the other end of the baffle being separated from the suction side wall; and a film cooling hole being arranged through the isolation plate, the film cooling hole being arranged downstream of the baffle.

[0021] When the turbine blade is working, the cooling air flows through the blade body from the blade tip end, and the cold air is blown out from the film cooling hole at the same time, so as to cool the blade tip of the blade body. By arranging the flow blocking piece in the groove of the blade tip and arranging the film cooling hole downstream of the flow blocking piece, the cooling air flowing from the blade tip end is blocked by the flow blocking piece when it flows to the flow blocking piece, and the cooling air flows through the gap between the flow blocking piece and the suction side wall, so that the cooling air does not pass through the film cooling hole. The cold air blown out of the film cooling hole cools the blade tip around the film cooling hole. By separating the flow directions of the two parts of the cold air by arranging the flow blocking piece, the two parts of the cold air flow separately without interfering with each other, reducing or even eliminating the repeated area generated by the coverage of the two parts of the cold air, and the cooling efficiency of the cold air resource can be improved.

[0022] 2. The gas turbine provided by the present application, wherein the turbine blade is installed in the casing, the turbine stator blade is also installed in the casing, the turbine stator blade is installed upstream of the turbine blade, the casing is provided with a slot cooling hole, the slot cooling hole is directed towards the turbine stator blade and the turbine blade, and the slot cooling hole is obliquely arranged towards the turbine blade. By arranging the oblique slot cooling hole, the cooling air is obliquely blown to the top of the blade tip of the turbine blade from the upstream of the turbine blade, so that the cooling air can fully contact and exchange heat with the isolation plate at the top of the blade tip of the turbine blade, and the cooling efficiency of the cooling air is improved.

[0023] 3. The gas turbine provided by the present application, wherein the outlet end of the slot cooling hole is provided with a flow blocking part near one side of the turbine stator blade, and the flow blocking part extends towards the direction away from the slot cooling hole. By arranging the flow blocking part, the high-temperature gas from the direction of the stator blade collides with the flow blocking part after colliding with the turbine blade, so that the high-temperature gas is generated on the upstream side of the turbine blade, and the contact between the high-temperature gas and the blade tip of the turbine blade is reduced. At the same time, the vortex generated at the flow blocking part can prevent the cold air blown out of the slot cooling hole from entering the upstream of the turbine blade, so that the cold air is blown to the blade tip of the turbine blade, the utilization rate of the cold air is improved, and the cooling effect is increased. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the specific embodiments or the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0025] Figure 1 The structure diagram of the turbine blade provided in the embodiments of the present application.

[0026] Figure 2 This is a schematic diagram of the cool air coverage area at the tip of a turbine blade provided in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the structure of a gas turbine provided in an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram showing the installation positions of the stationary turbine blades and the moving turbine blades in a gas turbine according to an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram of the structure of the slotted cooling port provided in an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram of the airflow around the slot cooling port provided in an embodiment of the present invention.

[0031] Explanation of reference numerals in the attached drawings: 1. Pressure sidewall; 2. Suction sidewall; 3. Isolation plate; 4. Baffle; 5. Film cooling hole; 6. Casing; 7. Turbine stationary blade; 8. Slotted cooling port; 9. Baffle. Detailed Implementation

[0032] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] Furthermore, the technical features involved in the different embodiments of the application described below can be combined with each other as long as there is no conflict.

[0036] Embodiment 1

[0037] Figure 1 And Figure 2 A turbine blade provided by the embodiment is shown in the figure, which comprises a blade body, a flow blocking piece 4 and a film cooling hole 5.

[0038] The blade body comprises a pressure side wall 1 and a suction side wall 2, both of which are arc-shaped, and a partition plate 3 is connected between the pressure side wall 1 and the suction side wall 2. The partition plate 3, the pressure side wall 1 and the suction side wall 2 form a groove-shaped tip at the end of the blade body. The flow blocking piece 4 is installed on the partition plate 3, one end of the flow blocking piece 4 is connected with the pressure side wall 1, and the other end is arranged separately from the suction side wall 2. The film cooling hole 5 is arranged through the partition plate 3, and the film cooling hole 5 is arranged downstream of the flow blocking piece 4.

[0039] The flow blocking piece 4 is arranged vertically with the pressure side wall 1. The length of the flow blocking piece 4 is 40% to 60% of the groove width at the installation position of the flow blocking piece 4, such as 40%, 45%, 50%, 55% or 60%. In the embodiment, the length of the flow blocking piece 4 is half of the groove width at the installation position of the flow blocking piece 4.

[0040] The bottom of the flow blocking piece 4 is connected with the partition plate 3, and the top of the flow blocking piece 4 is flush with the pressure side wall 1. The height of the flow blocking piece 4 is 1% to 3% of the height of the blade body, such as 1%, 1.5%, 2%, 2.5% or 3%. In the embodiment, the height of the flow blocking piece 4 is 1% of the height of the blade body.

[0041] As shown in the figure, Figure 1 A three-dimensional structure enlarged view of the tip of the turbine blade with the rib as the flow blocking piece 4 and the film cooling hole 5 provided by the embodiment is shown in the figure. Compared with the traditional groove-shaped tip structure, the tip groove of the embodiment provided has a rib as the flow blocking piece 4, one end of the rib is connected with the pressure side wall 1 and is perpendicular to each other, and the other end is located on the middle arc line of the tip and is not connected with the suction side wall 2. The rib design introduces the slot cooling air to the suction side of the tip groove, and cools the area that cannot be cooled by the downstream film cooling hole 5. The tip groove of the embodiment provided has three film cooling holes 5, which are located on the flow separation line of the groove bottom surface downstream of the rib and are uniformly distributed. After the cooling air flows out of the film cooling hole 5, it is entrained by the pressure side corner vortex and the tip clearance leakage flow to flow in two directions of the pressure side shoulder wall and the suction side shoulder wall, so as to fully cool and protect the groove bottom surface. Figure 2The coverage range of the cold air at the tip is shown in the figure, wherein the shaded part is the coverage area of the cooling, and it can be seen that the tip wall is basically covered by the cold air under the action of the cooling slot structure of the casing 6 slot and the film cooling hole 5 of the tip wall.

[0042] Embodiment 2

[0043] Figures 3 to 6 A gas turbine turbine provided in the embodiment is shown, which has the turbine blade provided in the embodiment 1.

[0044] The turbine blade is installed in the casing 6, and the turbine vane 7 is also installed in the casing 6, the turbine vane 7 is installed upstream of the turbine blade, the casing 6 is provided with the slot cooling port 8, the slot cooling port 8 is directed towards the turbine vane 7 and the turbine blade, and the slot cooling port 8 is obliquely arranged towards the turbine blade.

[0045] The outlet end of the slot cooling port 8 is provided with the flow blocking part 9 near the side of the turbine vane 7, and the flow blocking part 9 extends towards the direction away from the slot cooling port 8. The height of the flow blocking part 9 is 1% to 3% of the height of the blade body of the turbine blade, such as 1%, 1.5%, 2%, 2.5%, 3%, the height of the flow blocking part 9 in the embodiment is the same as the height of the flow blocking part 4, which is 1% of the height of the blade body. The included angle between the slot cooling port 8 and the top surface of the turbine blade is any inclined angle in the range of 15° to 75°, such as 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°. In the embodiment, the included angle between the slot cooling port 8 and the top surface of the turbine blade is 30°.

[0046] In view of the problems of the cooling slot structure on the casing 6 at the upstream position of the blade tip and the overlapping of the cold air coverage range of the original film cooling hole 5 on the blade tip surface, the embodiment provides a gas turbine turbine with a groove-shaped tip rib and a film cooling hole 5 layout structure. By analyzing the cooling range of the cooling slot structure of the casing 6 at the upstream position of the blade tip, determining the flow field structure in the tip gap, adding a rib structure as the flow blocking part 4 on the tip wall, and changing the number and position of the film cooling hole 5, the cold air is fully and effectively covered on the groove bottom surface, the repetition of the cold air coverage range is avoided, and the utilization efficiency of the cold air resource is improved.

[0047] The convective heat transfer coefficient h is defined as follows (unit: W / (K·m 2 ):

[0048]

[0049] In the formula, q is the heat flux density of the tip wall (unit: W / m2 ) ; Ta is the fluid temperature near the tip wall (unit: K) ; Tw is the tip wall temperature (unit: K).

[0050] The wall cooling efficiency η is defined as:

[0051]

[0052] In the formula: T ∞ is the turbine mainstream temperature (unit: K) ; T w is the tip wall temperature (unit: K) ; T C is the cooling gas temperature (unit: K).

[0053] The gas turbine turbine provided in the embodiment applies the groove-shaped tip rib under the casing 6 slot cooling and the film cooling hole 5 layout, and is based on the traditional groove-shaped tip. It contains three features: one is the casing 6 cooling slot upstream of the tip, two is the rib in the tip groove as a flow blocking piece 4, and three is the film cooling hole 5 on the bottom surface of the tip groove.

[0054] The slot cooling port 8 of the upstream position of the blade tip leading edge, the slot cooling port 8 is located above the casing 6 step as a flow blocking part 9, and maintains an inclined structure feature. In order to avoid friction between the casing 6 step and the tip leading edge during the operation of the gas turbine, there is an axial gap between the casing 6 step and the tip leading edge. The slot width F of the slot cooling port 8 is 1% of the turbine blade height H, the inclination angle E of the slot cooling port 8 is 30°, and the step height T of the casing 6 is 1% of the turbine blade height H.

[0055] The rib structure is provided at 30% of the axial chord length position in the tip groove, and the rib is perpendicular to the pressure side wall 1. The length W of the rib is 50% of the groove width at the current position of the tip, and the width L of the rib is 1% of the turbine blade height H. There are three film cooling holes 5 downstream of the rib structure in the tip groove, which are located on the flow separation line of the groove bottom surface, and the three film cooling holes 5 are uniformly distributed. The diameter D of the film cooling hole 5 is 1% of the turbine blade height H.

[0056] The casing 6 cooling slot of the gas turbine turbine provided in the embodiment has two obvious features: the first is that the casing 6 cooling slot has a step structure in the radial direction, and the step height is equal to the tip gap size, which induces a rib trailing vortex in the axial gap between the step and the tip, and blocks the high-temperature mainstream gas into the tip gap. The second is that the casing 6 cooling slot has an axial inclination angle. When the inclination angle E of the cooling slot is 30°, it is easier to induce the cooling gas into the inside of the tip gap.

[0057] In the gas turbine provided in this embodiment, a rib is located within the blade tip groove. One end of the rib is connected to and perpendicular to the pressure side shoulder wall, while the other end is located on the mid-arc line of the blade tip and is not connected to the suction side shoulder wall. The rib design introduces the cool air from the groove into the suction side of the blade tip groove, cooling the area that cannot be cooled by the downstream film cooling holes 5.

[0058] The gas turbine provided in this embodiment has three film cooling holes 5 in the blade tip groove. These holes are located on the flow separation line of the bottom surface of the groove downstream of the rib and are evenly distributed. After the cold air flows out of the film cooling holes 5, it is drawn into the pressure side vortex and the blade tip gap leakage flow and flows in two directions: the pressure side shoulder wall and the suction side shoulder wall. This will provide sufficient cooling protection for the bottom surface of the groove.

[0059] exist Figure 6 In the flow field structure of the casing slot cooling structure region shown, the rib-back vortex within the axial gap between the step and the blade tip obstructs the flow of high-temperature mainstream combustion gas in the blade passage, preventing the high-temperature combustion gas from entering the blade tip gap from the leading edge of the blade tip. Simultaneously, it also obstructs the entry of the slot jet cool air from the axial gap into the blade passage's mainstream flow channel. Traditional cooling slots are generally vertically incident structures. In this embodiment, the inclination angle of the slot cooling inlet 8 is set to 30°. At this angle, the direction of the cool air inflow is more parallel to the direction of the blade tip gap, making it easier for the cool airflow to enter the blade tip gap for cooling.

[0060] Example 3

[0061] This embodiment provides a gas turbine generator set having the gas turbine described in Embodiment 2. The gas turbine enhances the efficiency of its turbine blades in utilizing cool air, thereby improving the cooling capacity of the turbine blades. This allows the turbine blades to operate at higher power under the current cool air supply, thus increasing the operating power of the gas turbine generator set.

[0062] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A gas turbine, characterized in that, Includes turbine driving blades, the turbine driving blades comprising: The blade body includes a pressure sidewall (1) and a suction sidewall (2), both of which are arc-shaped. A partition plate (3) is connected between the pressure sidewall (1) and the suction sidewall (2). The partition plate (3), the pressure sidewall (1), and the suction sidewall (2) form a grooved blade tip at the end of the blade body. A flow deflector (4) is installed on the isolation plate (3). One end of the flow deflector (4) is connected to the pressure side wall (1), and the other end is separated from the suction side wall (2). A film cooling hole (5) is provided through the isolation plate (3), and the film cooling hole (5) is located downstream of the flow baffle (4); Turbine motor blades are installed inside a casing (6), and turbine stationary blades (7) are also installed inside the casing (6). The turbine stationary blades (7) are installed upstream of the turbine motor blades. The casing (6) is provided with slotted cooling ports (8). The slotted cooling ports (8) face between the turbine stationary blades (7) and the turbine motor blades, and the slotted cooling ports (8) are inclined towards the turbine motor blades. A baffle (9) is provided at the outlet end of the slot cooling port (8) on the side near the turbine stationary blade (7), and the baffle (9) extends in a direction away from the slot cooling port (8).

2. The gas turbine according to claim 1, characterized in that, The flow deflector (4) is perpendicular to the pressure sidewall (1).

3. The gas turbine according to claim 2, characterized in that, The length of the flow deflector (4) is 40% to 60% of the groove width at the installation position of the flow deflector (4).

4. The gas turbine according to any one of claims 1 to 3, characterized in that, The bottom of the baffle (4) is connected to the isolation plate (3), the top of the baffle (4) is flush with the pressure sidewall (1), and the height of the baffle (4) is 1% to 3% of the height of the blade body.

5. The gas turbine according to any one of claims 1 to 3, characterized in that, The height of the baffle (9) is 1% to 3% of the blade body height of the turbine driving blade.

6. The gas turbine according to any one of claims 1 to 3, characterized in that, The angle between the slotted cooling port (8) and the top surface of the turbine blade is 15°~75°.

7. A gas turbine generator set, characterized in that, A gas turbine as described in any one of claims 1 to 6.

Images