Tangential volute air inlet and lateral exhaust secondary reheating air turbine unit
By designing a secondary reheat air turbine unit with tangential volute inlet and lateral exhaust, and adopting multi-stage small enthalpy drop reaction blades and pre-twisted assembled structure, the efficiency and structural problems of existing air turbine equipment in the compressed air energy storage system are solved, and efficient and stable air turbine operation is achieved.
Patent Information
- Application Number
- CN202423216971.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-12-26
AI Technical Summary
Existing air turbine equipment cannot meet the commercialization needs of compressed air energy storage systems, especially in terms of structural design and efficiency.
A secondary reheat air turbine unit with tangential volute inlet and lateral exhaust was designed. It adopted multi-stage small enthalpy drop reaction blades, pre-twisted assembly structure, absolute dead point arrangement and volute inlet structure, combined with the cat's claw and centering beam connection between the high and medium pressure cylinders and the bearing box to form a stable unit structure.
It improves the efficiency of the high-pressure steam turbine, reduces intake loss and welding deformation, enhances the expansion adaptability and rapid start-up capability of the unit, and reduces the unit length and the expansion difference between dynamic and static.
Smart Images
Figure CN223374468U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a secondary reheat air turbine unit with tangential volute air intake and lateral exhaust. Background Art
[0002] Compressed air energy storage (CAES) is a new energy storage technology experiencing rapid development. Currently, it is the only large-scale, long-duration physical energy storage technology comparable to pumped hydro storage, offering significant advantages in functionality, cost, lifespan, and efficiency. Air turbines are crucial components of CAES systems. However, existing air turbines are unable to meet the demands of further commercialization. There is an urgent need to develop an air turbine with a rational structural design and high stage and cycle efficiencies to meet the operational requirements of CAES systems. Utility Model Content
[0003] The purpose of the utility model is to solve the above-mentioned problems and provide a secondary reheat air turbine unit with tangential volute intake and lateral exhaust.
[0004] The above purpose is achieved through the following technical solutions:
[0005] A secondary reheat air turbine unit with tangential volute intake and lateral exhaust, comprising: a front bearing housing, a middle bearing housing, a rear bearing housing, high and medium pressure cylinders, a low pressure cylinder, and a rotor. The high and medium pressure cylinders are each supported by four cat claws resting on the bearing housing. The high and medium pressure cylinders and the bearing housing are connected below the horizontal center plane by a positioning center beam.
[0006] The high and medium pressure cylinders include a high and medium pressure outer cylinder, a high and medium pressure rotor, a high pressure inner cylinder and a medium pressure inner cylinder. The high pressure inner cylinder adopts a tangential volute air intake method and is provided with a first-stage horizontal static vane in the high pressure inner cylinder air intake passage. The high pressure air inlets on both sides of the high pressure inner cylinder are each connected to a main air regulating combined valve.
[0007] The low-pressure cylinder is a double-layer cylinder structure, comprising a low-pressure outer cylinder and a low-pressure inner cylinder. The low-pressure inner cylinder is divided into two oppositely arranged flow channels in a double-dividing form.
[0008] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust is provided with a thrust bearing in the middle bearing box. The unit is provided with three absolute dead points, which are respectively located at the center of the middle bearing box, the middle of the low-pressure cylinder and the center of the rear bearing box.
[0009] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the middle bearing box, low-pressure cylinder, and rear bearing box are respectively restricted in center movement by two lateral positioning keys and two axial positioning keys pre-buried in the foundation, forming an absolute dead point of the unit.
[0010] In the secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the high- and medium-pressure rotors and the low-pressure rotors are connected by a flange-type rigid coupling to form a shaft system. The axial position of the shaft system is positioned by the thrust plate on the medium-pressure side of the high- and medium-pressure rotors of the unit, and the thrust plate surrounds the thrust bearing.
[0011] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the high-pressure and medium-pressure rotor blades of the high-pressure inner cylinder and the medium-pressure inner cylinder both adopt multi-stage small enthalpy drop reaction blades and a pre-twisted assembly structure. The circulation of the high-pressure inner cylinder is 9-stage circulation, and the circulation of the medium-pressure inner cylinder is 5-stage circulation.
[0012] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust has a medium-pressure air inlet and a medium-pressure exhaust port on the lower side of the medium-pressure inner cylinder, and adopts a bottom-in and bottom-out method for gas circulation.
[0013] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the low-pressure inner cylinder adopts a double-division flow structure, and the low-pressure inner cylinder has a low-pressure air intake port and a low-pressure exhaust port, which are circulated through the lower half of the lateral volute intake and lateral exhaust.
[0014] In the secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the low-pressure rotor side is connected to the generator through a coupling gasket and connecting bolts. Beneficial effects
[0015] 1. The high-pressure inner cylinder of the utility model adopts horizontal stator blades, 2×180° volute air intake, and a multi-stage small enthalpy drop reaction design. After the main steam enters the high-pressure inner cylinder, it performs work through the first-stage horizontal stator blades, which can effectively reduce the flow loss of the steam inlet part and the tangential non-uniformity of the inlet parameters of the first-stage stator blades. The aerodynamic performance is improved by more than 1.3%, thereby improving the efficiency of the high-pressure steam turbine.
[0016] 2. Except for the low-pressure blades, the other static blades and moving blades of the utility model adopt a pre-twisted assembled structure. Compared with the traditional welded partition, the assembled structure has no welds, avoids welding deformation, and better ensures the flow accuracy.
[0017] 3. The utility model is directly connected to the high-pressure inner cylinder air inlet through the main regulating combined valve, eliminating the air guide pipe structure, and the cylinder is volute-type air intake, which minimizes the air intake loss.
[0018] 4. The high and medium pressure cylinders and the bearing box of the utility model are connected by a cat's claw and a fixed center beam structure. The structure is mature and stable and can well meet the expansion requirements of the unit.
[0019] 5. The low-pressure inner cylinder of the utility model adopts a double-diversion form to be divided into two oppositely arranged flow channels. The flow channels are symmetrical on the left and right. Under the same power, the steam intake volume is large, which can effectively reduce the length of the last-stage blades and reduce the length of the unit.
[0020] 6. The absolute dead point and relative dead point of the utility model are both located in the middle bearing box. This arrangement of high and medium pressure cylinders can not only make the cylinder and the rotor expand in the same direction, greatly reducing the expansion difference between the dynamic and static cylinders, but also effectively reduce the absolute expansion of the cylinder, which is beneficial to the rapid start-up and load change of the unit. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Attachment Figure 1 It is a longitudinal sectional view of the utility model;
[0022] Attachment Figure 2 It is the main view of the utility model;
[0023] Attachment Figure 3 It is a top view of the utility model;
[0024] Attachment Figure 4 This is a structural diagram of the sliding pin system of the utility model;
[0025] Attachment Figure 5 It is a schematic diagram of the positioning center beam structure;
[0026] Attachment Figure 6 It is a schematic diagram of the reaction blade structure;
[0027] Attachment Figure 7 This is a schematic diagram of the direct connection between the main steam regulating combined valve and the high and medium pressure cylinders;
[0028] In the figure: 1. Front bearing box; 2. High and medium pressure outer cylinders; 3. High pressure inner cylinder; 4. High and medium pressure rotors; 5. Middle bearing box; 6. Low pressure outer cylinder; 7. Low pressure inner cylinder; 8. Rear bearing box; 9. Low pressure rotor; 10. Positioning center beam; 11. Horizontally placed stationary blades; 12. Medium pressure inner cylinder; 13. Second stage turbine; 14. Circulation channel; 17. Cat's claw; 18. High pressure air inlet; 19. High pressure exhaust; 20. Medium pressure air inlet; 21. Medium pressure exhaust; 22. Low pressure air inlet; 23. Generator; 24. Main air regulating combined valve; 25. Low pressure exhaust; 26. Thrust bearing; 27. Reaction blade. DETAILED DESCRIPTION
[0029] Reference Figure 1-Figure 7 A secondary reheat air turbine unit with tangential volute intake and lateral exhaust, comprising: a front bearing box 1, a middle bearing box 5, a rear bearing box 8, a high and medium pressure cylinder, a low pressure cylinder and a rotor;
[0030] The flow of this unit is divided into three stages of turbines. The compressed air enters the high-pressure inner cylinder through the main air regulating combined valve, and flows through the first-stage turbine to perform work. The high-pressure inner cylinder is a first-stage turbine. The gas is discharged and reheated before entering the second-stage turbine to perform work. The medium-pressure inner cylinder is a second-stage turbine, and then discharged from the medium-pressure lower exhaust port. After reheating, it enters the low-pressure inner cylinder, and after flowing through the low-pressure cylinder to perform work, it is finally discharged from the exhaust port of the low-pressure inner cylinder.
[0031] The high and medium pressure cylinders are supported by four cat claws 17, which are placed on the bearing box. The high and medium pressure cylinders are connected to the bearing box below the horizontal center plane by a positioning center beam 10.
[0032] The high and medium pressure cylinders include a high and medium pressure outer cylinder 2, a high and medium pressure rotor 4, a high pressure inner cylinder 3 and a medium pressure inner cylinder 12. The high pressure inner cylinder adopts a tangential volute air intake method and a first-level horizontal static blade 11 is arranged in the high pressure inner cylinder air intake channel. The high pressure air inlets 18 on both sides of the high pressure inner cylinder are each connected to a main air regulating combined valve 24. The main air regulating combined valve is directly connected to the high and medium pressure inner cylinder air inlets, eliminating the air guide pipe structure. The cylinder is volute air intake, which minimizes the air intake loss.
[0033] The low-pressure cylinder is a double-layer cylinder structure, including a low-pressure outer cylinder 6 and a low-pressure inner cylinder 7. The low-pressure inner cylinder is divided into two oppositely arranged flow channels 14 in a double-dividing form.
[0034] Reference Figure 4 , a secondary reheat air turbine unit with tangential volute intake and lateral exhaust, wherein a thrust bearing 26 is provided in the middle bearing box, and the unit is provided with three absolute dead points, namely, the center of the middle bearing box, the middle of the low-pressure cylinder and the center of the rear bearing box;
[0035] Referring to the unit's sliding pin system diagram, the unit has three absolute dead points: the center of the middle bearing box, the middle of the low-pressure cylinder, and the center of the rear bearing box. The middle bearing box, low-pressure cylinder, and rear bearing box are each restricted in their center movement by two transverse locating keys and two axial locating keys embedded in the foundation, forming the unit's absolute dead points.
[0036] During operation, the medium pressure cylinder can expand freely in the axial and transverse directions with the absolute dead point as the center. The high and medium pressure cylinders are supported by four "cat claws" respectively, and the "cat claws" are placed on the bearing box;
[0037] Below the horizontal center plane, the high and medium pressure cylinders and bearing housings are connected by a centering beam, enhancing unit stability. During turbine expansion, the center of the center bearing housing remains fixed, while its front, via the centering beam, pushes the high and medium pressure cylinders and the front bearing housing along the unit's axis, toward the engine head. The front bearing housing is restrained by guide keys on the base frame, allowing it to slide freely axially but not laterally. Pressure plates on the sides of the front bearing housing limit any tendency for the housing to tilt or lift. This sliding pin system has proven effective and smooth expansion.
[0038] The high- and low-pressure rotors are connected by flanged rigid couplings, forming a shafting system. The shafting system's axial position is determined by the thrust plate on the intermediate-pressure side of the high- and low-pressure rotors. The thrust plate surrounds the thrust bearing, forming the dead center between the static and dynamic components of the unit. As the unit's stator components expand and contract, the center of the center bearing housing, where the thrust bearing resides, remains unchanged. Therefore, the entire shafting system expands outward from this dead center. When heated, the high- and low-pressure rotors expand toward the engine head, with the thrust bearing as the dead center. The low-pressure rotor expands toward the generator, with the thrust bearing as the center.
[0039] The absolute dead point and relative dead point are both located in the middle bearing box. This arrangement of high and medium pressure cylinders can not only make the cylinder and the rotor expand in the same direction, greatly reducing the expansion difference between the dynamic and static cylinders, but also effectively reduce the absolute expansion of the cylinder, which is beneficial to the rapid start-up and load change of the unit.
[0040] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the middle bearing box, low-pressure cylinder, and rear bearing box are respectively restricted in center movement by two lateral positioning keys and two axial positioning keys pre-buried in the foundation, forming an absolute dead point of the unit.
[0041] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the high and medium pressure rotors and the low pressure rotor 9 are connected by a flange-type rigid coupling to form a shaft system, which can well meet the expansion requirements of the unit. The axial position of the shaft system is positioned by the thrust plate on the medium pressure side of the high and medium pressure rotors of the unit, and the thrust plate surrounds the thrust bearing.
[0042] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the high-pressure and medium-pressure rotor blades of the high-pressure inner cylinder and the medium-pressure inner cylinder both adopt multi-stage small enthalpy drop reaction blades 27 and a pre-twisted assembly structure. The circulation of the high-pressure inner cylinder is 9-stage circulation, and the circulation of the medium-pressure inner cylinder is 5-stage circulation.
[0043] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust has a medium-pressure air inlet 20 and a medium-pressure exhaust port 21 on the lower side of the medium-pressure inner cylinder, and adopts a bottom-in and bottom-out method for gas circulation.
[0044] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the low-pressure inner cylinder adopts a double-divided flow structure, and the low-pressure inner cylinder has a low-pressure air intake port 22 and a low-pressure exhaust port 25, which are circulated through the lower half of the lateral volute intake and lateral exhaust.
[0045] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the low-pressure rotor side is connected to the generator 23 through a coupling gasket and connecting bolts. The generator is located on the low-pressure cylinder side and is connected to the low-pressure rotor through a coupling to convert mechanical energy into electrical energy output.
Claims
1. A secondary reheat air turbine unit with tangential volute intake and lateral exhaust, comprising: The front bearing box, the middle bearing box, the rear bearing box, the high and medium pressure cylinders, the low pressure cylinder and the rotor are characterized in that: the high and medium pressure cylinders are supported by four cat claws respectively, the cat claws are placed on the bearing box, and the high and medium pressure cylinders and the bearing box are connected by a positioning center beam below the horizontal center plane; the high and medium pressure cylinders include a high and medium pressure outer cylinder, a high and medium pressure rotor, a high pressure inner cylinder and a medium pressure inner cylinder, the high pressure inner cylinder adopts a tangential volute air intake method and a first-level horizontal static blade is arranged in the high pressure inner cylinder air intake channel, and the high pressure air inlets on both sides of the high pressure inner cylinder are each connected to a main air regulating combined valve; the low pressure cylinder is a double-layer cylinder structure, including a low pressure outer cylinder and a low pressure inner cylinder, and the low pressure inner cylinder is divided into two oppositely arranged flow channels through a double diversion form.
2. A secondary reheat air turbine unit with tangential volute intake and lateral exhaust according to claim 1, characterized in that: The middle bearing box is provided with a thrust bearing. The unit is provided with three absolute dead points, which are respectively located at the center of the middle bearing box, the middle of the low-pressure cylinder and the center of the rear bearing box.
3. The secondary reheat air turbine unit with tangential volute intake and lateral exhaust according to claim 1, characterized in that: The middle bearing box, low-pressure cylinder and rear bearing box are respectively limited in center movement by two transverse positioning keys and two axial positioning keys embedded in the foundation, forming an absolute dead point of the unit.
4. The secondary reheat air turbine unit with tangential volute intake and lateral exhaust according to claim 1, characterized in that: The high and medium pressure rotors and the low pressure rotor are connected by a flange-type rigid coupling to form a shaft system. The axial position of the shaft system is positioned by the thrust plate on the medium pressure side of the high and medium pressure rotors of the unit, and the thrust plate surrounds the thrust bearing.
5. The secondary reheat air turbine unit with tangential volute intake and lateral exhaust according to claim 1, characterized in that: The high and medium pressure rotor blades of the high-pressure inner cylinder and the medium-pressure inner cylinder both adopt multi-stage small enthalpy drop reaction blades and a pre-twisted assembly structure. The circulation of the high-pressure inner cylinder is 9-stage circulation, and the circulation of the medium-pressure inner cylinder is 5-stage circulation.
6. The secondary reheat air turbine unit with tangential volute intake and lateral exhaust according to claim 1, characterized in that: The lower side of the medium-pressure inner cylinder is provided with a medium-pressure air inlet and a medium-pressure air outlet, and gas circulation is carried out in a bottom-in and bottom-out manner.
7. The secondary reheat air turbine unit with tangential volute intake and lateral exhaust according to claim 1, characterized in that: The low-pressure inner cylinder adopts a double-dividing flow structure, and has a low-pressure air inlet and a low-pressure exhaust port on the low-pressure inner cylinder. Air is taken in through the lower half of the volute and exhausted laterally.
8. The secondary reheat air turbine unit with tangential volute intake and lateral exhaust according to claim 4, characterized in that: The low-pressure rotor side is connected to the generator through a coupling gasket and connecting bolts.