High-speed shaft system and turbine generator set based on hybrid bearings in turbine power generation system

Abstract

This invention provides a high-speed shaft system and turbine generator set for a turbine power generation system based on hybrid bearings. The system includes a high-speed motor rotor, a coupling, a thrust disk bushing, a compressor impeller, a connecting bushing, and a turbine impeller. The turbine impeller passes sequentially through the connecting bushing, the compressor impeller, and the thrust disk bushing. The high-speed motor rotor and the thrust disk bushing are connected by a coupling. Air-bearing radial bearings are installed on the high-speed motor rotor, the thrust disk bushing, and the connecting bushing. A magnetic axial bearing is also installed on the thrust disk bushing. This invention forms a turbine compressor rotor by having the turbine impeller pass sequentially through the connecting bushing, the compressor impeller, and the thrust disk bushing. The high-speed motor rotor is supported by air-bearing radial bearings, and the turbine compressor rotor is supported by both air-bearing radial bearings and magnetic axial bearings. This high-speed shaft system for the power generation system has advantages such as simple structure and ability to adapt to large axial forces, making it suitable for high-pressure systems and high-power Brayton power generation systems.

Description

Technical Field

[0001] This invention relates to the field of Brayton thermoelectric conversion, and more specifically, to a high-speed shaft system and turbine generator set of a turbine power generation system based on hybrid bearings. Background Technology

[0002] The Brayton cycle is an effective way to convert heat energy into electrical energy, especially for space applications with high weight and compactness. Compared with the Rankine and Stirling cycles, the Brayton cycle balances conversion efficiency and system quality, making it suitable for megawatt-level high-power space power systems. Megawatt-level power output can be achieved by using multiple units in parallel, typically in the hundreds of kilowatt range. The turbocharger generator set is the core equipment of the Brayton cycle system, and its high-speed shaft system is also the only moving part of the system, having a decisive impact on conversion efficiency and service life.

[0003] Due to the requirements of service life and compactness in space applications, space Brayton cycles must employ oil-free floating bearings, and the miniaturization of turbine-compressor generator sets is achieved by increasing the cycle pressure system. Although there are existing application cases of 100-kilowatt-class micro gas turbines based on air-bearing bearings, under high-pressure systems, the compressor and turbine will generate large axial forces, several times the magnitude of the axial forces of existing 100-kilowatt-class micro gas turbine rotors. Therefore, the problem of axial force balance needs to be solved.

[0004] To address the aforementioned issues, a high-speed shaft system capable of adapting to large axial forces is needed for a turbine power generation system. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this invention is to provide a high-speed shaft system and turbine generator set based on hybrid bearings for a turbine power generation system.

[0006] According to the present invention, a high-speed shaft system for a turbine power generation system based on hybrid bearings includes: a high-speed motor rotor, a coupling, a thrust disk bushing, a compressor impeller, a connecting bushing, and a turbine impeller. The turbine impeller passes sequentially through the connecting bushing, the compressor impeller, and the thrust disk bushing. The high-speed motor rotor and the thrust disk bushing are connected by the coupling. Air-bearing radial bearings are provided on the high-speed motor rotor, the thrust disk bushing, and the connecting bushing. A magnetic axial bearing is also provided on the thrust disk bushing.

[0007] Preferably, the high-speed motor rotor, the coupling, the thrust disc bushing, the compressor impeller, the connecting bushing, the turbine impeller, and the air-bearing radial bearing are coaxially arranged.

[0008] Preferably, the turbine impeller includes a tie rod that passes sequentially through the connecting bushing, the compressor impeller, and the thrust disk bushing, and the tie rod does not extend to the outside of the thrust disk bushing. The end of the tie rod is fastened to the thrust disk bushing by a lock nut.

[0009] Preferably, the thrust disk bushing extends outward from the middle to form a thrust disk, the magnetic levitation axial bearing is sleeved on the thrust disk, and the gap between the magnetic levitation axial bearing and the thrust disk is between 0.1 and 0.5 mm.

[0010] Preferably, a third air-floating radial bearing is fitted on the outer side of the end of the thrust disc bushing away from the compressor impeller, and the gap between the third air-floating radial bearing and the thrust disc bushing is between 0.1 and 0.5 mm. The end of the thrust disc bushing close to the compressor impeller is inserted into the inner side of the compressor impeller and the two are interference-fitted.

[0011] Preferably, a first air-bearing radial bearing and a second air-bearing radial bearing are respectively fitted at both ends of the high-speed motor rotor, and the gap between the first air-bearing radial bearing, the second air-bearing radial bearing and the high-speed motor rotor is between 0.1 and 0.5 mm.

[0012] Preferably, a fourth air-floating radial bearing is fitted on the outer side of the connecting bushing, and the gap between the fourth air-floating radial bearing and the connecting bushing is between 0.1 and 0.5 mm. One end of the connecting bushing is fitted on the outer side of the turbine impeller and the two are interference-fitted. The other end of the connecting bushing is inserted into the inner side of the compressor impeller and the two are interference-fitted.

[0013] Preferably, the coupling includes a flexible diaphragm coupling.

[0014] According to the present invention, a turbine generator set includes the above-mentioned high-speed shaft system of the turbine generator system based on hybrid bearings, and also includes a housing, which is sleeved and installed on the outside of the high-speed shaft system of the turbine generator system based on hybrid bearings.

[0015] Preferably, both the air-bearing radial bearing and the magnetic levitation axial bearing are mounted on the housing, with the air-bearing radial bearing and the magnetic levitation axial bearing arranged perpendicularly.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This invention involves a turbine impeller sequentially passing through a connecting shaft sleeve, a compressor impeller, and a thrust disk shaft sleeve, and positioning them via the stops and locking nuts of each component to form a turbine compressor rotor. The turbine compressor rotor and the high-speed motor rotor are connected to both sides of the coupling via stops. The high-speed motor rotor is supported by an air-bearing radial bearing, and the turbine compressor rotor is supported by both an air-bearing radial bearing and a magnetic axial bearing. This high-speed shaft system of the power generation system has advantages such as simple structure and ability to adapt to large axial forces, and is suitable for high-pressure systems and high-power Brayton power generation systems.

[0018] 2. The motor and the rotors on both sides of the turbine compressor of the present invention are driven by a flexible diaphragm coupling, which is beneficial to rotor dynamics design and makes it easier to meet the rigid rotor design requirements of the suspension bearing.

[0019] 3. By using an air-bearing bearing on the motor side, the present invention simplifies the system and simultaneously ensures motor rotor cooling; by using a magnetic levitation bearing with stronger load-bearing capacity and active control on the axial thrust bearing of the turbine compressor side, the problem of balancing large axial forces under high pressure system can be solved. Attached Figure Description

[0020] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0021] Figure 1 This is a schematic diagram illustrating the structure of the high-speed shaft system of a turbine power generation system based on hybrid bearings, which is the main feature of this invention.

[0022] As shown in the figure:

[0023] High-speed motor rotor 1 Coupling 2 Thrust disc bushing 3

[0024] 4 Compressor impeller 5 Connecting shaft sleeve 6 Turbine impeller

[0025] Locking nut 7 First air-bearing radial bearing 8 Second air-bearing radial bearing 9

[0026] Third air-bearing radial bearing 10; Fourth air-bearing radial bearing 11; Magnetic levitation axial bearing 12 Detailed Implementation

[0027] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0028] Example 1

[0029] like Figure 1As shown, a high-speed shaft system for a turbine power generation system based on hybrid bearings according to the present invention includes: a high-speed motor rotor 1, a coupling 2, a thrust disk bushing 3, a compressor impeller 4, a connecting bushing 5, and a turbine impeller 6. The turbine impeller 6 passes sequentially through the connecting bushing 5, the compressor impeller 4, and the thrust disk bushing 3. The high-speed motor rotor 1 and the thrust disk bushing 3 are connected by a coupling 2. Air-bearing radial bearings are provided on the high-speed motor rotor 1, the thrust disk bushing 3, and the connecting bushing 5. A magnetic axial bearing 12 is also provided on the thrust disk bushing 3.

[0030] The purpose of this invention is to provide a high-speed shaft system for a turbine power generation system based on hybrid bearings, which can balance the axial force generated by the shaft system under high pressure and improve the operating stability of the shaft system.

[0031] The air-bearing radial bearing is the radial bearing of the rotor, which overcomes the rotor's weight, supports the rotor, and allows the rotor to rotate at high speed. The magnetic levitation axial bearing 12 is the axial thrust bearing of the rotor, which overcomes the rotor's axial force and maintains the rotor's axial position. During the start-up phase, the high-speed motor rotor 1 is the driving end, driving the thrust disc bushing 3, compressor impeller 4, connecting bushing 5, and turbine impeller 6 to rotate at high speed through the coupling 2. During the power generation phase, the high-speed motor rotor 1 is the passive end, driven by the turbine impeller 6 to rotate the connecting bushing 5, compressor impeller 4, and thrust disc bushing 3, and then driven by the coupling 2 to rotate the high-speed motor rotor 1 to generate electricity.

[0032] The high-speed motor rotor 1, coupling 2, thrust disc bushing 3, compressor impeller 4, connecting bushing 5, turbine impeller 6, and air-bearing radial bearing are coaxially arranged.

[0033] The turbine impeller 6 includes a tie rod that passes sequentially through the connecting sleeve 5, the compressor impeller 4, and the thrust disk sleeve 3. The tie rod does not extend beyond the outside of the thrust disk sleeve 3. The end of the tie rod is securely connected to the thrust disk sleeve 3 via a lock nut 7. The thrust disk sleeve 3, compressor impeller 4, connecting sleeve 5, and turbine impeller 6 are positioned by the stops of each component and the lock nut 7, forming a turbine compressor rotor. In this application, the stops of each component are securely connected by an interference fit, which can transmit torque and ensure coaxiality.

[0034] The thrust disk bushing 3 extends outward from the middle to form a thrust disk. Magnetic levitation axial bearings 12 are arranged on both sides of the thrust disk to balance the axial force of the high-speed shaft system of the turbine power generation system. The gap between the magnetic levitation axial bearings 12 and the thrust disk is between 0.1 and 0.5 mm. The axial thrust bearing on the turbine compressor side adopts a magnetic levitation bearing with stronger load-bearing capacity and active control, which can meet the problem of balancing large axial forces under high pressure system.

[0035] A third air-floating radial bearing 10 is fitted on the outer side of the thrust disc bushing 3 at the end away from the compressor impeller 4, and the gap between the third air-floating radial bearing 10 and the thrust disc bushing 3 is between 0.1 and 0.5 mm. The end of the thrust disc bushing 3 near the compressor impeller 4 is inserted into the inner side of the compressor impeller 4 and the two are interference-fitted.

[0036] The high-speed motor rotor 1 has a first air-bearing radial bearing 8 and a second air-bearing radial bearing 9 respectively mounted on both ends. The gap between the first air-bearing radial bearing 8, the second air-bearing radial bearing 9 and the high-speed motor rotor 1 is between 0.1 and 0.5 mm. Using air-bearing bearings on the motor side simplifies the system and also ensures cooling of the motor rotor.

[0037] A fourth air-floating radial bearing 11 is fitted on the outer side of the connecting sleeve 5. The gap between the fourth air-floating radial bearing 11 and the connecting sleeve 5 is between 0.1 and 0.5 mm. One end of the connecting sleeve 5 is fitted on the outer side of the turbine impeller 6 and the two are interference-fitted. The other end of the connecting sleeve 5 is inserted into the inner side of the compressor impeller 4 and the two are interference-fitted.

[0038] Coupling 2 includes a flexible diaphragm coupling, which can compensate for misalignment of the rotors on both sides, achieving a rigid design for both rotors and meeting the rotor stiffness requirements of the air-bearing radial bearing. The motor and the rotors on both sides of the turbine compressor are driven by the flexible diaphragm coupling, which is beneficial to rotor dynamics design and makes it easier to meet the rigid rotor design requirements of the suspension bearing.

[0039] The high-speed shaft system of the power generation system of the present invention has advantages such as simple structure and ability to adapt to large axial forces. It is suitable for high-pressure systems and high-power Brayton thermoelectric conversion systems, and has significant application advantages, especially in situations where there are extremely high requirements for bearing operating environment and axial force balance.

[0040] Example 2

[0041] A turbine generator set includes a high-speed shaft system of a turbine generator system based on hybrid bearings as described in Embodiment 1, and also includes a housing, which is a stationary component and is fitted onto the outside of the high-speed shaft system of the turbine generator system based on hybrid bearings. Both an air-bearing radial bearing and a magnetic levitation axial bearing 12 are mounted on the housing. During generator operation, neither the radial bearing nor the thrust bearing contacts the rotor shaft system. The air-bearing radial bearing and the magnetic levitation axial bearing 12 are arranged perpendicularly.

[0042] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and 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 this application.

[0043] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A high-speed shaft system for a turbine power generation system based on hybrid bearings, characterized in that, include: The high-speed motor rotor (1), coupling (2), thrust disk bushing (3), compressor impeller (4), connecting bushing (5) and turbine impeller (6) are provided. The turbine impeller (6) includes a tie rod. The tie rod of the turbine impeller (6) passes through the connecting bushing (5), the compressor impeller (4) and the thrust disk bushing (3) in sequence. The high-speed motor rotor (1) and the thrust disk bushing (3) are connected by the coupling (2). Air-bearing radial bearings are provided on the high-speed motor rotor (1), the thrust disk bushing (3) and the connecting bushing (5). A magnetic axial bearing (12) is also provided on the thrust disk bushing (3).

2. The high-speed shaft system of the turbine power generation system based on hybrid bearings as described in claim 1, characterized in that, The high-speed motor rotor (1), the coupling (2), the thrust disc bushing (3), the compressor impeller (4), the connecting bushing (5), the turbine impeller (6), and the air-bearing radial bearing are coaxially arranged.

3. The high-speed shaft system of the turbine power generation system based on hybrid bearings as described in claim 1, characterized in that, The pull rod does not extend to the outside of the thrust disc bushing (3), and the end of the pull rod is fastened to the thrust disc bushing (3) by a locking nut (7).

4. The high-speed shaft system of the turbine power generation system based on hybrid bearings as described in claim 1, characterized in that, The thrust disk bushing (3) extends outward from the middle to form a thrust disk, the magnetic levitation axial bearing (12) is sleeved on the thrust disk, and the gap between the magnetic levitation axial bearing (12) and the thrust disk is between 0.1 and 0.5 mm.

5. The high-speed shaft system of the turbine power generation system based on hybrid bearings as described in claim 1, characterized in that, The thrust disc bushing (3) is fitted with a third air-floating radial bearing (10) on the outer side of the end away from the compressor impeller (4), and the gap between the third air-floating radial bearing (10) and the thrust disc bushing (3) is between 0.1 and 0.5 mm. The end of the thrust disc bushing (3) close to the compressor impeller (4) is inserted into the inner side of the compressor impeller (4) and the two are interference-fitted.

6. The high-speed shaft system of the turbine power generation system based on hybrid bearings as described in claim 1, characterized in that, The high-speed motor rotor (1) is fitted with a first air-bearing radial bearing (8) and a second air-bearing radial bearing (9) at both ends. The gaps between the first air-bearing radial bearing (8), the second air-bearing radial bearing (9) and the high-speed motor rotor (1) are both between 0.1 and 0.5 mm.

7. The high-speed shaft system of the turbine power generation system based on hybrid bearings as described in claim 1, characterized in that, The outer side of the connecting sleeve (5) is fitted with a fourth air-floating radial bearing (11), and the gap between the fourth air-floating radial bearing (11) and the connecting sleeve (5) is between 0.1 and 0.5 mm. One end of the connecting sleeve (5) is fitted on the outer side of the turbine impeller (6) and the two are interference-fitted. The other end of the connecting sleeve (5) is inserted into the inner side of the compressor impeller (4) and the two are interference-fitted.

8. The high-speed shaft system of the turbine power generation system based on hybrid bearings as described in claim 1, characterized in that, The coupling (2) includes a flexible diaphragm coupling.

9. A turbine generator set, characterized in that, The high-speed shaft system of the turbine power generation system based on hybrid bearings as described in any one of claims 1-8 further includes a housing, which is sleeved and installed on the outside of the high-speed shaft system of the turbine power generation system based on hybrid bearings.

10. The turbine generator set as claimed in claim 9, characterized in that, Both the air-bearing radial bearing and the magnetic levitation axial bearing (12) are mounted on the housing, with the air-bearing radial bearing and the magnetic levitation axial bearing (12) arranged perpendicularly.

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