Single-shaft combined cycle power plant and flywheel

Abstract

The invention discloses a single-shaft combined cycle power plant and a flywheel for use in a power grid. The single-shaft combined cycle power plant comprises a gas turbine with a first shaft, a generator with a second shaft and a flywheel coaxially connected between the gas turbine and the generator, and the single-shaft combined cycle power plant has a first working state and a second working state. The flywheel is connected to the gas turbine at a first side through a first shaft and connected to the generator at a second side through a second shaft, the flywheel is in a disc shape, the thickness of the flywheel is Z, the flywheel is provided with a thickness reduction part at the center position, the maximum thickness of the thickness reduction part is X, and Z is larger than X. According to the single-shaft combined cycle power plant, the flywheel is designed to be in the disc shape, the flywheel is provided with the thickness reducing part, the needed axial installation space is reduced, the structure is simple, assembling and disassembling are easy, an additional foundation is not needed, and cost is effectively reduced.

Description

Technical Field

[0001] The present application relates to a single shaft combined cycle power plant and a flywheel for use in an electrical grid. Background Art

[0002] In single-shaft combined cycle power plants, grid stabilizers are needed to improve grid stability and reliability. Phase regulators, as a type of grid stabilizer, are able to provide or absorb reactive power in the grid to improve the stability of the power system.

[0003] In the single-shaft combined cycle power plant of the prior art, in order to enable the phase regulator to work as a grid stabilizer, the flywheel that needs to be installed is usually relatively large in size and occupies more axial space. However, there is not enough space in the power plant to install the flywheel and its balancing system.

[0004] In the prior art, the following two methods are usually used to solve this problem: The first method is to remove the gas turbine for installing the flywheel. The second method is to move the phase regulator and rebuild the foundation to install the phase regulator.

[0005] The above two solutions of the prior art are difficult to implement and costly. Summary of the invention

[0006] In view of this, the present application proposes a single-shaft combined cycle power plant and a related flywheel for use in a power grid. The flywheel is formed in a disc shape, which reduces the axial size of the flywheel and increases the radial size of the flywheel, thereby overcoming the technical problem in the prior art that the flywheel occupies more axial space.

[0007] The single-shaft combined cycle power plant according to the present application is connected to a power grid, and includes a gas turbine having a first shaft, a generator having a second shaft, and a flywheel coaxially connected therebetween. The single-shaft combined cycle power plant has a first working state and a second working state.

[0008] In the first working state, the gas turbine is connected to the generator to drive the generator to output electrical energy to the power grid through mechanical energy.

[0009] In the second working state, the first shaft of the gas turbine is disconnected from the flywheel, and the excess electric energy in the grid drives the generator, so that the generator rotates as a motor to output mechanical energy and drives the flywheel to rotate to consume the excess electric energy in the grid, so as to be used as a phase regulator.

[0010] The flywheel is connected to the gas turbine via a first shaft at a first side and to the generator via a second shaft at a second side. The flywheel is disc-shaped, the thickness of the flywheel is Z, and the flywheel has a reduced thickness portion at a central position. The maximum thickness of the reduced thickness portion is X, wherein Z>X.

[0011] According to the single-shaft combined cycle power plant of the present application, the flywheel is designed to be disc-shaped with a thickness-reduced portion, which reduces the required axial installation space, has a simple structure, is easy to assemble and disassemble, does not require an additional foundation, and effectively reduces costs.

[0012] Further, the radius of the flywheel is Y, and the maximum thickness of the reduced thickness portion and the radius of the flywheel have the following relationship: Y≤2X.

[0013] The radius of the flywheel is less than or equal to twice the maximum thickness of the reduced thickness portion, so as to prevent the radial dimension of the flywheel from being too large to interfere with the ground or the ceiling, and to prevent the flywheel from being too heavy to exceed the carrying capacity of the first shaft and the second shaft.

[0014] Further, the thickness reduction portion includes: a first recess, located at the first side of the flywheel, coaxial with the central axis of the flywheel, and used to cooperate with the first shaft, and the minimum depth of the first recess is D1, wherein D1=0.2X; and a second recess, located at the second side of the flywheel, coaxial with the central axis of the flywheel, and used to cooperate with the second shaft, and the minimum depth of the second recess is D2, wherein 0.05X≤D2≤0.1X.

[0015] The thickness reduction portion includes a first recess and a second recess, which can respectively cooperate with the first shaft and the second shaft. Compared with a flywheel having a thickness of X and no thickness variation, the flywheel of the present application increases the rotational inertia of the flywheel.

[0016] Further, the first recess has a first protrusion protruding toward the first side of the flywheel, and the first protrusion has a first flange extending radially outward at a top periphery thereof for connecting with the first shaft.

[0017] The first recess is provided with a first flange, which is convenient for connection with the first shaft and simplifies the assembly process.

[0018] Further, the second recess has a second protrusion protruding toward the second side of the flywheel, and the second protrusion has a second flange extending radially outward at a top periphery thereof for connecting with the second shaft.

[0019] The second recess is provided with a second flange, which is convenient for connection with the second shaft and simplifies the assembly process.

[0020] Further, the first flange and the second flange both have through holes for fixing the flywheel to the first shaft and the second shaft by bolts and nuts. The flywheel is fixed to the corresponding shaft by bolts and nuts, which is easy to assemble and reduces costs.

[0021] Furthermore, a first annular groove coaxial with the central axis of the flywheel is provided in the first recess for placing a balancing weight. Furthermore, a second annular groove coaxial with the central axis of the flywheel is provided in the second recess for placing a balancing weight. Placing a balancing weight in the flywheel improves the stability of the flywheel rotation.

[0022] Furthermore, the first recess and the second recess are configured such that the first recess can accommodate the connecting end of the first shaft and the second recess can accommodate the connecting end of the second shaft, so as to facilitate the installation and removal of the flywheel and simplify the assembly process.

[0023] According to another embodiment of the present application, a flywheel is provided for a single-shaft combined cycle power plant, wherein the flywheel is connected to a gas turbine via a first shaft at a first side and to a generator via a second shaft at a second side, the flywheel is disc-shaped, the thickness of the flywheel is Z, the flywheel has a reduced thickness portion at a central position, the maximum thickness of the reduced thickness portion is X, wherein Z>X.

[0024] The flywheel according to the present application is designed in a disc shape with a portion having a reduced thickness, which reduces the required axial installation space, has a simple structure, is easy to assemble and disassemble, does not require an additional foundation, and effectively reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 Schematic diagram of the connection relationship between the gas turbine, phase regulator and flywheel.

[0027] Figure 2 It is a perspective view of a flywheel according to the present application.

[0028] Figure 3 is a cross-sectional view of a flywheel according to the present application.

[0029] The reference numerals are as follows:

[0030] 1. Flywheel

[0031] 2. Gas turbine

[0032] 3. Camera adjustment

[0033] 4. First axis

[0034] 5. Second axis

[0035] 10. Thickness reduction part

[0036] 11. The first concave part

[0037] 12. The second concave part

[0038] 13. First protrusion

[0039] 14. Second protrusion

[0040] 15. First flange

[0041] 16. Second flange

[0042] 17. Through hole DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application is further described in detail with reference to the following embodiments.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] As this application Figure 1 , Figure 2 and Figure 3 As shown, a single-shaft combined cycle power plant according to the present application is connected to a power grid, and the single-shaft combined cycle power plant includes a gas turbine 2 having a first shaft 4, a generator 3 having a second shaft 5, and a flywheel 1 coaxially connected therebetween, and is characterized in that the single-shaft combined cycle power plant has a first working state and a second working state.

[0047] In the first working state, the gas turbine 2 is connected to the generator 3 to drive the generator 3 to output electrical energy to the power grid through mechanical energy; in the second working state, the first shaft 4 of the gas turbine 2 is disconnected from the flywheel 1, and the excess electrical energy in the power grid drives the generator 3, so that the generator 3 is used as an electric motor to rotate to output mechanical energy, and drives the flywheel 1 to rotate to consume the excess electrical energy in the power grid, so as to be used as a phase regulator.

[0048] The flywheel 1 is connected to the gas turbine 2 via a first shaft 4 at a first side and to the generator 3 via a second shaft 5 at a second side. The flywheel 1 is in the shape of a disk. The thickness of the flywheel 1 is Z. The flywheel 1 has a reduced thickness portion 10 at a central position. The maximum thickness of the reduced thickness portion 10 is X, wherein Z>X.

[0049] According to the single-shaft combined cycle power plant of the present application, the flywheel is designed to be disc-shaped with a thickness-reduced portion, which reduces the required axial installation space, has a simple structure, is easy to assemble and disassemble, does not require an additional foundation, and effectively reduces costs.

[0050] like Figure 3 As shown, the radius of the flywheel 1 is Y, and the maximum thickness of the reduced thickness portion 10 and the radius of the flywheel 1 have the following relationship: Y≤2X. The radius of the flywheel is less than or equal to twice the maximum thickness of the reduced thickness portion, preventing the radial size of the flywheel from being too large to interfere with the ground or the ceiling. At the same time, the flywheel weight is prevented from being too large to exceed the bearing capacity of the first shaft and the second shaft.

[0051] The reduced thickness portion 10 includes a first recess 11 and a second recess 12. The first recess 11 is located at a first side of the flywheel 1, coaxial with the central axis of the flywheel 1, and is used to cooperate with the first shaft 4. The minimum depth of the first recess 11 is D1, where D1=0.2X. The second recess 12 is located at a second side of the flywheel 1, coaxial with the central axis of the flywheel 1, and is used to cooperate with the second shaft 5. The minimum depth of the second recess 12 is D2, where 0.05X≤D2≤0.1X.

[0052] Therefore, it can be concluded that the value of the thickness Z of the flywheel is between 1.25 and 1.3 times the maximum thickness X of the recess.

[0053] Compared with a flywheel having a thickness X and no thickness variation, the flywheel of the present application has a thickness Z greater than the maximum thickness X of the recess, which increases the moment of inertia of the flywheel.

[0054] The first concave portion 11 and the second concave portion 12 are circular concave portions, and both have a radius P. The size of the radius P can be designed according to the radius of the first shaft 4 and the second shaft 5. The larger the radius of the first shaft 4 and the second shaft 5, the larger the radius P. And vice versa.

[0055] The first recess 11 has a first protrusion 13 protruding toward the first side of the flywheel 1 . The first protrusion 13 has a first flange 15 extending radially outward at a top periphery thereof for connecting with the first shaft 4 .

[0056] The second recess 12 has a second protrusion 14 protruding toward the second side of the flywheel 1 . The second protrusion 14 has a second flange 16 extending radially outward at a top periphery thereof for connecting with the second shaft 5 .

[0057] The first flange 15 and the second flange 16 each have a through hole 17 for fixing the flywheel 1 to the first shaft 4 and the second shaft 5 by bolts and nuts. The first shaft 4 and the second shaft 5 also have corresponding flanges to cooperate with the first flange 15 and the second flange 16.

[0058] A first annular groove 18 coaxial with the central axis of the flywheel 1 is provided in the first recess 11 for accommodating a balancing weight.

[0059] According to another embodiment of the present application, a second annular groove coaxial with the central axis of the flywheel 1 is provided in the second recess 12 for placing a balancing weight.

[0060] The first recess 11 and the second recess 12 are configured such that the first recess 11 can accommodate the connection end of the first shaft 4 , and the second recess 12 can accommodate the connection end of the second shaft 5 .

[0061] According to one embodiment of the present application, the maximum thickness of the reduced thickness portion 10 may be set to X according to the distance between the gas turbine 2 and the generator 3 .

[0062] Specifically, the smaller the distance between the gas turbine 2 and the generator 3, the smaller the maximum thickness X of the reduced thickness portion 10. The larger the distance between the gas turbine 2 and the generator 3, the larger the maximum thickness X of the reduced thickness portion 10.

[0063] According to one embodiment of the present application, a flywheel is also provided for a single-shaft combined cycle power plant, wherein the flywheel 1 is connected to a gas turbine 2 via a first shaft 4 on a first side, and is connected to a generator 3 via a second shaft 5 on a second side, and is characterized in that the flywheel 1 is disc-shaped, the thickness of the flywheel 1 is Z, and the flywheel 1 has a reduced thickness portion 10 at a central position, and the maximum thickness of the reduced thickness portion 10 is X, wherein Z>X.

[0064] The flywheel according to the present application is designed in a disc shape with a portion having a reduced thickness, which reduces the required axial installation space, has a simple structure, is easy to assemble and disassemble, does not require an additional foundation, and effectively reduces costs.

[0065] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A single-shaft combined cycle power plant, connected to a power grid, comprising a gas turbine (2) having a first shaft (4), a generator (3) having a second shaft (5), and a flywheel (1) coaxially connected therebetween, characterized in that: The single-shaft combined cycle power plant has a first working state and a second working state. In the first working state, the gas turbine (2) is connected to the generator (3) so as to drive the generator (3) to output electrical energy to the power grid through mechanical energy. In the second working state, the first shaft (4) of the gas turbine (2) is disconnected from the flywheel (1), and the excess electric energy in the power grid drives the generator (3), so that the generator (3) rotates as a motor to output mechanical energy and drives the flywheel (1) to rotate, so as to consume the excess electric energy in the power grid, so as to be used as a phase regulator. The flywheel (1) is connected to the gas turbine (2) at a first side via the first shaft (4), and is connected to the generator (3) at a second side via the second shaft (5). The flywheel (1) is in the shape of a disk, and the thickness of the flywheel (1) is Z. The flywheel (1) has a reduced thickness portion (10) at a central position, and the maximum thickness of the reduced thickness portion (10) is X, wherein Z>X.

2. The single-shaft combined cycle power plant according to claim 1, characterized in that: The radius of the flywheel (1) is Y, and the maximum thickness of the reduced thickness portion (10) and the radius of the flywheel (1) have the following relationship: Y≤2X.

3. The single-shaft combined cycle power plant according to claim 2, characterized in that: The reduced thickness portion (10) comprises: a first recess (11), located at a first side of the flywheel (1), coaxial with a central axis of the flywheel (1), and adapted to cooperate with the first shaft (4), wherein a minimum depth of the first recess (11) is D1, wherein D1=0.2X; and The second recess (12) is located at the second side of the flywheel (1), coaxial with the central axis of the flywheel (1), and is used to cooperate with the second shaft (5). The minimum depth of the second recess (12) is D2, wherein 0.05X≤D2≤0.1X.

4. The single-shaft combined cycle power plant according to claim 3, characterized in that: The first recess (11) has a first protrusion (13) protruding toward the first side of the flywheel (1), and the first protrusion (13) has a first flange (15) extending radially outward at its top periphery for connecting with the first shaft (4).

5. The single-shaft combined cycle power plant according to claim 4, characterized in that: The second recess (12) has a second protrusion (14) protruding toward the second side of the flywheel (1), and the second protrusion (14) has a second flange (16) extending radially outward at its top periphery for connecting with the second shaft (5).

6. The single-shaft combined cycle power plant according to claim 5, characterized in that: The first flange (15) and the second flange (16) both have through holes (17) for fixedly connecting the flywheel (1) to the first shaft (4) and the second shaft (5) by means of bolts and nuts.

7. The single-shaft combined cycle power plant according to claim 3, characterized in that: The first recess (11) is provided with a first annular groove (18) coaxial with the central axis of the flywheel (1) for accommodating a balancing weight.

8. The single-shaft combined cycle power plant according to claim 3, characterized in that: The second recess (12) is provided with a second annular groove coaxial with the central axis of the flywheel (1) for accommodating a balancing weight.

9. The single-shaft combined cycle power plant according to claim 3, characterized in that: The first recess (11) and the second recess (12) are configured such that the first recess (11) can accommodate the connecting end of the first shaft (4), and the second recess (12) can accommodate the connecting end of the second shaft (5).

10. A flywheel for a single-shaft combined cycle power plant, the flywheel (1) being connected to a gas turbine (2) at a first side via a first shaft (4) and connected to a generator (3) at a second side via a second shaft (5), characterized in that: The flywheel (1) is in the shape of a circular disc, the thickness of the flywheel (1) is Z, the flywheel (1) has a reduced thickness portion (10) at a central position, the maximum thickness of the reduced thickness portion (10) is X, wherein Z>X.

Images