A turbine blade and a gas turbine turbine having the same

Abstract

The present application relates to the technical field of gas turbine turbine cooling, in particular to a turbine blade and a gas turbine turbine with the same. The turbine blade comprises: a blade body, which is hollow inside, the thickness of the blade body gradually increases from the tip to the opposite end, and the top of the blade body is provided with a partition plate; a pressure side shoulder wall is arranged on the top of the blade body and extends along the side edge of the blade body in an arc shape; a suction side shoulder wall is arranged on the top of the blade body and extends along the other side edge of the blade body in an arc shape to be connected with the pressure side shoulder wall at the tip of the blade body, and the end of the suction side shoulder wall away from the tip of the blade body is separated from the pressure side shoulder wall to form an inlet space between the pressure side shoulder wall and the suction side shoulder wall. By removing the pressure side shoulder wall and the suction side shoulder wall in the tip leading edge area, the flow of cold air entering the tip gap is increased, and the cooling efficiency of the tip wall surface is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas turbine cooling technology, in particular to a turbine blade and a gas turbine with the same. BACKGROUND

[0002] Unlike traditional fossil energy, new energy power generation is greatly affected by external environmental factors such as sunlight and wind intensity, and the power generation capacity is unstable, difficult to predict, and highly volatile, which is difficult to match the requirements of the demand side of the power grid. During the peak and valley periods of electricity consumption, the phenomena of "electricity shortage" and "abandonment of electricity" occur. In order to ensure the normal use of new energy power generation, a certain amount of energy storage and peak shaving facilities are required. Due to its rapid start and stop and variable working condition characteristics, the gas turbine has always been one of the important means of power peak shaving.

[0003] The tip of the turbine blade of the gas turbine is in a high-temperature environment for a long time, and the tip material is prone to fatigue fracture under the impact of high-temperature gas. In order to isolate the contact between the tip material and the high-temperature gas, the gas turbine in the prior art adopts a gas film cooling method. A cooling slot structure is designed at the position of the casing upstream of the tip to cool the tip wall surface. However, due to the geometric structure of the groove-shaped tip, a large amount of cooling gas flowing out of the upstream cooling slot cannot directly enter the inside of the tip groove, and thus the tip wall surface cannot be cooled and protected. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defect that the groove-shaped tip edge of the turbine blade in the prior art blocks the cooling gas, so that the cooling gas cannot directly enter the inside of the tip groove, and thus the tip wall surface cannot be cooled and protected, thereby providing a turbine blade and a gas turbine with the same.

[0005] In order to solve the above technical problems, the present application provides a turbine blade, comprising:

[0006] a blade body, which is a hollow structure, the thickness of the blade body gradually increases from the tip to the other end, and the top of the blade body is provided with a partition plate;

[0007] a pressure side shoulder wall, which is arranged at the top of the blade body and extends along the side edge of the blade body in an arc shape;

[0008] a suction side shoulder wall, which is arranged at the top of the blade body and extends along the other side edge of the blade body in an arc shape to connect with the pressure side shoulder wall at the tip of the blade body, and the end of the suction side shoulder wall away from the tip of the blade body is separated from the pressure side shoulder wall to form an inflow space between the pressure side shoulder wall and the suction side shoulder wall.

[0009] Optionally, the isolation plate is provided with air film cooling holes.

[0010] Optionally, the air film cooling holes are arranged downstream of the inflow space.

[0011] Optionally, the height of the pressure side shoulder wall and / or the suction side shoulder wall is 1%-3% of the height of the blade body.

[0012] Optionally, the height of the pressure side shoulder wall and / or the suction side shoulder wall is 1%-3% of the thickness of the blade body.

[0013] The present application also provides a gas turbine turbine with the turbine blade.

[0014] Optionally, the turbine blade is installed in a casing, the casing is also provided with turbine vanes, the turbine vanes are installed upstream of the turbine blade, the casing is provided with a slot cooling hole, the slot cooling hole is directed towards the space between the turbine vanes and the turbine blade, and the slot cooling hole is inclined towards the turbine blade.

[0015] Optionally, the outlet end of the slot cooling hole is provided with a flow blocking part on the side close to the turbine vane, and the flow blocking part extends away from the slot cooling hole.

[0016] Optionally, the height of the flow blocking part is 1%-3% of the height of the blade body of the turbine blade.

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

[0018] The technical scheme of the present application has the following advantages:

[0019] 1. The turbine blade provided by the present application comprises: a blade body with a hollow structure, the thickness of the blade body gradually increases from the tip to the opposite end, and the top of the blade body is provided with an isolation plate; a pressure side shoulder wall arranged on the top of the blade body and extending along the side edge of the blade body in an arc shape; and a suction side shoulder wall arranged on the top of the blade body and extending along the other side edge of the blade body in an arc shape to connect with the pressure side shoulder wall at the tip of the blade body, and the end of the suction side shoulder wall away from the tip of the blade body is separated from the pressure side shoulder wall to form an inflow space between the pressure side shoulder wall and the suction side shoulder wall.

[0020] By removing the pressure side shoulder wall and the suction side shoulder wall in the tip region of the turbine blade, the tip as a whole still maintains the state of the grooved tip, at this time the tip leakage flow in the tip groove still presents an S-shaped flow trajectory, and the tip clearance leakage flow rate still remains at a low level. After the pressure side shoulder wall and the suction side shoulder wall in the tip region are removed, the cooling air enters the groove from the inflow space formed between the pressure side shoulder wall and the suction side shoulder wall, the flow rate of the cold air entering the tip clearance is increased, and the cooling efficiency of the tip wall surface is improved. At the same time, the starting position of the pressure side corner vortex in the tip groove is also moved backward, the area of the region impacted by the tip clearance leakage flow on the tip wall surface is reduced, thereby reducing the high heat exchange region of the tip wall surface, and further protecting the tip wall surface by high-efficiency cooling.

[0021] 2. The turbine blade provided by the present application is provided with a gas film cooling hole on the partition plate. By arranging the gas film cooling hole, another flow of cold air is blown out from the inner cavity of the blade body into the tip groove, so that a layer of cold air film is formed on the top of the blade body, and the impact of high-temperature combustion gas on the tip of the blade body is isolated.

[0022] 3. The gas turbine turbine provided by the present application is provided with a turbine blade installed in the casing, and a turbine stator blade installed in the casing, the turbine stator blade is installed upstream of the turbine blade, a slot cooling port is arranged on the casing, the slot cooling port faces the turbine stator blade and the turbine blade, and the slot cooling port is arranged obliquely towards the turbine blade. By arranging the slot cooling port obliquely towards the turbine blade, the cold air blown out by the slot cooling port can directly cool the tip of the turbine blade, reduce the heat exchange between the cold air and the high-temperature combustion gas from the upstream of the casing, and improve the cooling efficiency of the cold air blown out by the slot cooling port on the tip of the turbine blade. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or 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 also be obtained by those skilled in the art without creative labor.

[0024] Figure 1 The structure diagram of the turbine blade provided in the embodiments of the present application.

[0025] Figure 2 The structure diagram of the gas turbine turbine provided in the embodiments of the present application.

[0026] Figure 3A schematic diagram of the installation position of a turbine vane and a turbine blade in a gas turbine provided in an embodiment of the present application.

[0027] Figure 4 A schematic diagram of the structure of a slot cooling hole provided in an embodiment of the present application.

[0028] Figure 5 A schematic diagram of the air flow field around a slot cooling hole provided in an embodiment of the present application.

[0029] Figure 6 A schematic diagram of the coverage range of a blade tip cooling gas for a turbine blade provided in an embodiment of the present application.

[0030] BRIEF DESCRIPTION OF DRAWINGS 1. Blade body; 2. Pressure side shoulder wall; 3. Suction side shoulder wall; 4. Film cooling hole; 5. Casing; 6. Turbine vane; 7. Slot cooling hole; 8. Flow blocking portion; 9. Vane end wall; 10. Blade end wall. DETAILED DESCRIPTION

[0031] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0032] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. 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.

[0034] In addition, the technical features involved in the different embodiments of the application described below can be combined with each other as long as they do not conflict with each other.

[0035] Embodiment 1

[0036] Figure 1 A turbine blade provided by the embodiment is shown, which includes a blade body 1, a pressure side shoulder wall 2 and a suction side shoulder wall 3.

[0037] In order to reduce the tip leakage loss, the gas turbine often adopts a groove-shaped tip structure. The groove-shaped tip is improved on the basis of the flat tip. The middle of the groove-shaped tip is a groove structure, which is called a tip groove. The pressure side of the tip groove is called the pressure side shoulder wall 2, and the suction side of the tip groove is called the suction side shoulder wall 3. Under the action of the geometric structures of the pressure side shoulder wall 2 and the suction side shoulder wall 3, a scraping vortex and a pressure side corner vortex are formed in the tip groove. The tip clearance leakage flow presents an S-shaped flow trajectory in the tip clearance under the action of the above two vortices, and the through-flow area of the tip clearance leakage flow is reduced, thereby reducing the leakage amount of the tip clearance leakage flow. However, the groove-shaped tip is affected by its geometric structure, and a large amount of cold gas in the upstream cannot directly enter the inside of the tip groove, and thus cannot cool and protect the tip wall surface. In order to solve the above problem, the embodiment takes a first-stage moving blade of a high-pressure turbine as the research object, and changes the geometric structure of the shoulder wall of the groove-shaped tip to improve the cooling efficiency of the tip wall surface and enhance the cooling effect of the tip wall surface.

[0038] The blade body 1 provided by the embodiment is a hollow structure, the thickness of the blade body 1 gradually increases from the tip end to the opposite end, and the top of the blade body 1 is provided with a partition plate. The pressure side shoulder wall 2 is arranged at the top of the blade body 1 and extends along the side edge of the blade body 1 in an arc shape. The suction side shoulder wall 3 is arranged at the top of the blade body 1 and extends along the other side edge of the blade body 1 in an arc shape to be connected with the pressure side shoulder wall 2 at the tip end of the blade body 1. The end of the suction side shoulder wall 3 away from the tip end of the blade body 1 is separated from the pressure side shoulder wall 2, so as to form an inflow space between the pressure side shoulder wall 2 and the suction side shoulder wall 3.

[0039] The partition plate is provided with a film cooling hole 4. The film cooling hole 4 is arranged downstream of the inflow space. The height of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is 1%-3% of the height of the blade body 1. In the embodiment, the height of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is flush, and the height of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is 2% of the height of the blade body 1. The thickness of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is 1%-3% of the height of the blade body 1. In the embodiment, the thickness of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is 1% of the height of the blade body 1.

[0040] Compared with the conventional concave tip, the turbine blade tip provided in the embodiment is free of the pressure side shoulder wall 2 and the suction side shoulder wall 3 in the tip leading edge region. The pressure side shoulder wall 2 of the tip starts at 30% of the tip circumferential chord length, and the suction side shoulder wall 3 of the tip starts at 40% of the tip circumferential chord length. The line connecting the starting point of the tip pressure side shoulder wall 2 and the starting point of the tip suction side shoulder wall 3 is perpendicular to the tip mean camber line. By removing the pressure side shoulder wall 2 and the suction side shoulder wall 3 in the tip leading edge region, the tip of the turbine blade still maintains the state of the concave tip, and the tip leakage flow in the tip concave is still in the S-shaped flow trajectory, and the tip clearance leakage flow rate is still maintained at a low level. After removing the pressure side shoulder wall 2 and the suction side shoulder wall 3 in the tip leading edge region, the starting position of the pressure side corner vortex in the tip concave is also moved backward, the area of the region impacted by the tip clearance leakage flow on the tip wall surface is reduced, and thus the high heat exchange region of the tip wall surface is reduced. Since the pressure side shoulder wall 2 and the suction side shoulder wall 3 in the tip leading edge region have the blocking effect on the upstream slot cold air entering the tip concave, after removing the pressure side shoulder wall 2 and the suction side shoulder wall 3 in the tip leading edge region, the flow rate of the slot cold air entering the tip clearance is increased, and the cooling efficiency of the tip wall surface is improved.

[0041] Embodiment 2

[0042] Figures 2 to 6 A gas turbine turbine provided in the embodiment is shown, which has the turbine blade provided in embodiment 1.

[0043] The gas turbine turbine is composed of the turbine stator blades 6 and the turbine rotor blades. On both sides of the turbine stator blades 6 and the turbine rotor blades in the radial direction are the stator blade end walls 9, the rotor blade end walls 10 and the casing 5 respectively. Among them, both sides of the turbine stator blades 6 are connected to the stator blade end wall 9 and the casing 5 respectively, and they are all stationary components; the turbine rotor blades are only connected to the rotor blade end wall 10 on one side and are rotating components. There is a radial tip clearance between the stationary casing 5 and the rotating turbine rotor blades to prevent friction. Due to the pressure gradient between the tip pressure side and the suction side, the high-temperature fluid in the cascade channel directly passes through the tip clearance under the drive of this pressure gradient, forming a tip clearance leakage flow. The tip clearance leakage flow cannot do work on the rotor blades, reducing the work capacity of the turbine, which is called tip leakage loss. To reduce the tip leakage loss, gas turbines often adopt a grooved tip structure. The grooved tip is improved on the basis of a flat tip. The middle of the grooved tip is a groove structure, called the tip groove. The pressure side of the tip groove is called the pressure side shoulder wall 2, and the suction side of the tip groove is called the suction side shoulder wall 3. Under the action of the geometric structures of the pressure side shoulder wall 2 and the suction side shoulder wall 3, a scraping vortex and a pressure side corner vortex are formed in the tip groove. Under the action of the above two vortices, the tip clearance leakage flow has an S-shaped flow trajectory in the tip clearance, and the flow area of the tip clearance leakage flow is reduced, thereby reducing the leakage amount of the tip clearance leakage flow. Aiming at the problem that after a cooling slot is set upstream of the tip leading edge of the turbine rotor blade of a gas turbine, the grooved tip structure design blocks the cold air flow from entering the inside of the tip groove and the tip wall surface cannot be fully cooled, in this embodiment, the first-stage rotor blade of a certain high-pressure turbine is taken as the research object. By analyzing the flow field structure characteristics in the tip region, the flow characteristics of the cooling air flow and the tip clearance leakage flow are judged, and the tip geometric shape structure is optimized. Changing the starting positions of the tip pressure side shoulder wall 2 and the suction side shoulder wall 3 can effectively increase the flow rate of the casing slot cold air flow entering the tip groove, thereby improving the cooling efficiency of the tip wall surface.

[0044] In this embodiment, the turbine rotor blades are installed in the casing 5. The turbine stator blades 6 are also installed in the casing 5. The turbine stator blades 6 are installed upstream of the turbine rotor blades. A slot cooling port 7 is provided on the casing 5. The slot cooling port 7 faces between the turbine stator blades 6 and the turbine rotor blades, and the slot cooling port 7 is inclined towards the turbine rotor blades.

[0045] A baffle 8 is provided on the side of the outlet end of the slot cooling port 7 close to the turbine stator blades 6. The baffle 8 extends in a direction away from the slot cooling port 7. The height of the baffle 8 is 1% - 3% of the height of the blade body 1 of the turbine rotor blades. The included angle between the slot cooling port 7 and the top surface of the turbine rotor blades is 15° - 75°. In this embodiment, the height of the baffle is 1% of the height of the blade body 1 of the turbine rotor blades. The included angle between the slot cooling port 7 and the top surface of the turbine rotor blades is 30°.

[0046] The heat transfer coefficient h is defined as follows (unit: W / (K·m 2 )):

[0047]

[0048] In the above formula, q is the heat flux density of the tip surface (unit: W / m 2 ); T a is the fluid temperature near the tip surface (unit: K); and T w is the tip surface temperature (unit: K).

[0049] The wall cooling efficiency η is defined as follows:

[0050]

[0051] In the above formula, T ∞ is the temperature of the main flow of the turbine (unit: K); T w is the temperature of the tip surface (unit: K); and T C is the temperature of the cooling air (unit: K).

[0052] The gas turbine turbine provided by the embodiment is provided with a slot cooling hole 7 at an upstream position of the tip leading edge of the turbine blade; the tip of the turbine blade is taken as a reference for the concave groove-shaped tip, and the starting positions of the pressure side shoulder wall 2 and the suction side shoulder wall 3 are optimized, aiming to increase the cooling air flow in the tip gap, improve the cooling efficiency of the tip surface, and protect the normal operation of the tip material. The size of the tip gap between the tip of the turbine blade and the casing 5 is 1% of the height of the turbine blade, the shoulder wall height G of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is 2% of the height H of the turbine blade, and the shoulder wall width K of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is 1% of the height H of the turbine blade.

[0053] The slot cooling hole 7 at the upstream position of the tip leading edge of the turbine blade is located above the casing step and maintains an inclined structure. In order to avoid friction between the casing step and the tip leading edge during the operation of the gas turbine, there is an axial gap between the casing step and the tip leading edge. The slot width F of the slot cooling hole 7 is set to 1% of the height H of the turbine blade, the slot angle E of the slot cooling hole 7 is set to 30°, and the casing step height T of the flow blocking part 8 is set to 1% of the height H of the turbine blade.

[0054] Figure 5A three-dimensional enlarged view of the slot cooling hole 7 on the tip upstream casing 5 of the turbine blade is shown. The slot cooling hole 7 has a step structure in the vertical and radial direction, and the step height is equal to the tip gap size, which induces a rib wake vortex in the axial gap between the step and the tip, blocking the high-temperature main flow gas from entering the tip gap. The slot cooling hole 7 has an axial inclination, and when the cooling slot inclination E = 30°, it is easier to induce the cooling gas to enter the inside of the tip gap.

[0055] By comparing the flow field structure in the tip leading edge region of the turbine blade of the present embodiment with the groove-shaped tip of the turbine blade in the prior art, in the process of the cooling gas flow of the slot cooling hole on the casing upstream of the turbine blade in the prior art entering the tip groove, the throughflow area at the shoulder wall of the tip leading edge is small, and the position where the high-temperature main flow gas and the cooling gas flow meet above the shoulder wall forms a separation vortex, which reduces the throughflow area of the cooling gas and increases the resistance of the cooling gas entering the tip groove. Figure 4 A schematic diagram of the flow field structure in the tip leading edge region using the present embodiment is shown. Compared with the conventional groove-shaped tip structure, there is no shoulder wall structure at the tip leading edge position, and in the process of the cooling gas flow of the slot cooling hole on the casing upstream entering the tip groove, the throughflow area is always large; although there is still a separation vortex at the bottom surface of the tip groove, it has little effect on the overall throughflow area, and the resistance of the cooling gas entering the tip groove is reduced. The cooling efficiency of the tip wall surface is improved.

[0056] The tip with different starting positions of the pressure side shoulder wall 2 and the suction side shoulder wall 3 is also calculated using numerical simulation methods, and the numerical calculation results show that when the line connecting the starting points of the tip pressure side shoulder wall 2 and the tip suction side shoulder wall 3 is perpendicular to the tip mean camber line, the cooling effect of the tip wall surface is best, and at this time, the starting position of the tip pressure side shoulder wall 2 is 30% of the tip circumferential chord length, and the starting position of the tip suction side shoulder wall 3 is 40% of the tip circumferential chord length. Figure 6 A schematic diagram of the cooling gas coverage area on the tip wall surface of the turbine blade provided by the present embodiment from the slot cooling hole 7 is shown, wherein the shaded part is the cooling gas coverage area. By comparison, it can be found that when the tip designed by the present invention is used, the gas film cooling range of the tip wall surface extends towards the tip trailing edge, and the gas film cooling coverage area of the tip wall surface increases.

[0057] Obviously, the above embodiments are only examples for clear illustration, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A gas turbine, characterized in that, Includes turbine-driven blades, the turbine-driven blades comprising: The blade body (1) has a hollow structure inside. The thickness of the blade body (1) gradually increases from the tip to the opposite end. An isolation plate is provided on the top of the blade body (1). Pressure side shoulder wall (2) is provided on the top of the blade body (1), and the pressure side shoulder wall (2) extends in an arc shape along the side of the blade body (1); A suction side shoulder wall (3) is provided on the top of the blade body (1). The suction side shoulder wall (3) extends in an arc along the other side of the blade body (1) to connect with the pressure side shoulder wall (2) at the tip of the blade body (1). The end of the suction side shoulder wall (3) away from the tip of the blade body (1) is separated from the pressure side shoulder wall (2) so that an inlet space is formed between the pressure side shoulder wall (2) and the suction side shoulder wall (3). Turbine motor blades are installed inside the casing (5), and turbine stationary blades (6) are also installed inside the casing (5). The turbine stationary blades (6) are installed upstream of the turbine motor blades. The casing (5) is provided with slotted cooling ports (7). The slotted cooling ports (7) face between the turbine stationary blades (6) and the turbine motor blades, and the slotted cooling ports (7) are inclined towards the turbine motor blades. A flow-blocking part (8) is provided on the side of the outlet end of the slot cooling port (7) near the turbine stationary blade (6), and the flow-blocking part (8) extends in a direction away from the slot cooling port (7).

2. The gas turbine according to claim 1, characterized in that, The isolation plate is provided with air film cooling holes (4).

3. The gas turbine according to claim 2, characterized in that, The air film cooling hole (4) is located downstream of the inlet space.

4. The gas turbine according to any one of claims 1 to 3, characterized in that, The height of the pressure side shoulder wall (2) and / or the suction side shoulder wall (3) is 1%-3% of the height of the blade body (1).

5. The gas turbine according to claim 1, characterized in that, The thickness of the pressure side shoulder wall (2) and / or the suction side shoulder wall (3) is 1%-3% of the height of the blade body (1).

6. The gas turbine according to claim 1, characterized in that, The height of the baffle (8) is 1% to 3% of the height of the turbine blade body (1).

7. The gas turbine according to any one of claims 1 to 3, characterized in that, The angle between the slotted cooling port (7) and the top surface of the turbine blade is 15°~75°.

Images