Tangential volute air inlet and lateral exhaust secondary reheating air turbine unit

Abstract

The invention discloses a secondary reheating air turbine unit for tangential volute air inlet and lateral exhaust. Air turbine equipment which is reasonable in structural design and high in stage efficiency and circulation efficiency needs to be developed urgently so as to meet the operation requirement of a compressed air energy storage system. A high-pressure cylinder and a medium-pressure cylinder are respectively supported by four cat claws, the cat claws are lapped on a bearing box, and the high-pressure cylinder and the medium-pressure cylinder and the bearing box are connected below a horizontal split through a positioning center beam; the high-medium-pressure cylinder comprises a high-medium-pressure outer cylinder, a high-medium-pressure rotor, a high-pressure inner cylinder and a medium-pressure inner cylinder, the high-pressure inner cylinder adopts a tangential volute air inlet mode, meanwhile, a first-stage transverse stationary blade is arranged in an air inlet channel of the high-pressure inner cylinder, and high-pressure air inlets in the two sides of the high-pressure inner cylinder are each connected with a main air adjusting combined valve; the low-pressure cylinder is of a double-layer cylinder structure and comprises a low-pressure outer cylinder and a low-pressure inner cylinder, and the low-pressure inner cylinder is divided into two oppositely-arranged circulation channels in a double-flow-dividing mode. The secondary reheating air turbine unit is used for tangential volute air inlet and lateral exhaust.

Description

Technical Field

[0001] The invention relates to a secondary reheat air turbine unit with tangential volute air intake and lateral exhaust. Background Art

[0002] Compressed air energy storage is a new type of energy storage technology that is in a booming stage. It is currently the only large-scale, long-term physical energy storage technology that can be compared with pumped storage, and has significant advantages in terms of function, cost, life and efficiency. Air turbines are important equipment in compressed air energy storage systems. Existing air turbine equipment cannot meet the needs of further commercialization of compressed air energy storage systems. It is urgent to develop an air turbine equipment with a reasonable structural design, high stage efficiency and cycle efficiency to meet the operating requirements of compressed air energy storage systems. Summary of the invention

[0003] The object of the present invention is to solve the above-mentioned problems and to 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: A secondary reheat air turbine unit with tangential volute intake and lateral exhaust, comprising: a front bearing box, a middle bearing box, a rear bearing box, a high-pressure cylinder, a low-pressure cylinder and a rotor, wherein the high-pressure cylinder is supported by four cat claws respectively, and the cat claws are placed on the bearing box, and the high-pressure cylinder and the bearing box are connected below the horizontal center plane by a positioning center beam; The high and medium pressure cylinder comprises 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 mode and a first-stage horizontal stationary blade is arranged in the high pressure inner cylinder air intake passage. The high pressure air intake ports on both sides of the high pressure inner cylinder are respectively 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. The low-pressure inner cylinder is divided into two oppositely arranged flow channels in a double-dividing form.

[0005] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, wherein a thrust bearing is arranged in the middle bearing box, and 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.

[0006] 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 limited in center movement by two lateral positioning keys and two axial positioning keys embedded in the foundation, forming an absolute dead point of the unit.

[0007] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the high-pressure rotor and the low-pressure rotor are connected by a flange-type rigid coupling to form a shaft system, and the axial position of the shaft system is located by the thrust plate on the medium-pressure side of the high-pressure rotor of the unit, and the thrust plate surrounds the thrust bearing.

[0008] 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.

[0009] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust has a medium-pressure intake port and a medium-pressure exhaust port on the lower side of the medium-pressure inner cylinder, and adopts a bottom-intake and bottom-exhaust method for gas circulation.

[0010] 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 intake port and a low-pressure exhaust port, which are circulated in a lateral exhaust manner through the lower half of the lateral volute intake.

[0011] 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

[0012] 1. The high-pressure inner cylinder of the present invention adopts transverse stator blades, 2×180° volute air intake, and the flow adopts a multi-stage small enthalpy drop reaction design. After the main steam enters the high-pressure inner cylinder, it works through the first-stage transverse stator blades, which can effectively reduce the flow loss of the steam inlet part, reduce the tangential non-uniformity of the inlet parameters of the first-stage stator blades, improve the aerodynamic performance by more than 1.3%, and improve the efficiency of the high-pressure steam turbine.

[0013] 2. Except for the low-pressure blades, the other stationary blades and moving blades of the present invention adopt a pre-twisted assembled structure. Compared with the traditional welded partition, the assembled structure has no welds, avoiding welding deformation and better ensuring the flow accuracy.

[0014] 3. The present invention directly connects the main regulating combined valve with the high-pressure inner cylinder air inlet, eliminating the air guide pipe structure, and the cylinder is volute-cased for air intake, thereby minimizing air intake losses.

[0015] 4. The high and medium pressure cylinders and the bearing box of the present invention are connected by a cat's claw and a centering beam structure, which is mature and stable and can well meet the expansion requirements of the unit.

[0016] 5. The low-pressure inner cylinder of the present invention adopts a double-dividing 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.

[0017] 6. The absolute dead point and relative dead point of the present invention 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

[0018] Attached Figure 1 is a longitudinal sectional view of the present invention;

[0019] Attached Figure 2 It is a front view of the present invention; Attached Figure 3 is a top view of the present invention; Attached Figure 4 It is a structural diagram of the sliding pin system of the present invention; Attached Figure 5 It is a schematic diagram of the positioning center beam structure; Attached Figure 6 It is a schematic diagram of the reaction blade structure; Attached 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; 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. horizontal stationary blades; 12. medium pressure inner cylinder; 13. two-stage turbine; 14. circulation channel; 17. cat's claw; 18. high pressure air inlet; 19. high pressure exhaust port; 20. medium pressure air inlet; 21. medium pressure exhaust port; 22. low pressure air inlet; 23. generator; 24. main air regulating combined valve; 25. low pressure exhaust port; 26. thrust bearing; 27. reaction blade. DETAILED DESCRIPTION

[0020] The utility model is further described in detail below according to the accompanying drawings and embodiments: 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; 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 do work. The high-pressure inner cylinder is a first-stage turbine. The gas is discharged and reheated before entering the second-stage turbine to do 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, flows through the low pressure and does work, and is finally discharged from the exhaust port of the low-pressure inner cylinder.

[0021] 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 through a positioning center beam 10. 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 stationary 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 respectively 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 a volute air intake, which minimizes the air intake loss.

[0022] 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.

[0023] Reference Figure 4 , the secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the middle bearing box is provided with a thrust bearing 26, and the unit is provided with three absolute dead points, respectively at the center of the middle bearing box, the middle of the low-pressure cylinder and the center of the rear bearing box; Referring to the slide pin system diagram of the unit, the unit is equipped with 3 absolute dead points, which are located at 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, the low-pressure cylinder and the rear bearing box are respectively limited by two lateral positioning keys and two axial positioning keys embedded in the foundation to limit the center movement of the bearing box, forming the absolute dead points of the unit; During operation, the medium-pressure cylinder expands 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; The high and medium pressure cylinders and the bearing box are connected below the horizontal center plane by a positioning center beam to increase the stability of the unit; when the turbine expands, the center of the middle bearing box remains unchanged, and its front part pushes the high and medium pressure cylinders and the front bearing box to expand along the axial direction of the unit toward the head through the centering beam. The front bearing box is restricted by the guide key on the base frame and can slide freely along the axial direction, but cannot move laterally. The pressure plate on the side of the front bearing box limits any tendency of the bearing box to tilt or rise. This sliding pin system has been proven to have smooth expansion and good results through operation.

[0024] The high-pressure rotor and the low-pressure rotor are connected by flange rigid couplings to form a shaft system. The axial position of the shaft system is located by the thrust plate on the medium-pressure side of the high-pressure rotor of the unit. The thrust plate surrounds the thrust bearing, thus forming a dead point between the dynamic and static parts of the unit. When the stator components of the unit expand and contract, the center of the middle bearing box where the thrust bearing is located remains unchanged. Therefore, the entire shaft system expands to both sides with this as the dead point. After being heated, the high-pressure rotor expands toward the head with the thrust bearing as the dead point, and the low-pressure rotor expands toward the generator side with the thrust bearing as the center.

[0025] 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 parts of the cylinder, but also effectively reduce the absolute expansion of the cylinder, which is beneficial to the rapid start-up and load change of the unit.

[0026] 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 limited in center movement by two lateral positioning keys and two axial positioning keys embedded in the foundation, forming an absolute dead point of the unit.

[0027] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust, the high-pressure rotor 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 located by the thrust plate on the medium-pressure side of the high-pressure rotor of the unit, and the thrust plate surrounds the thrust bearing.

[0028] 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 adopt 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.

[0029] The secondary reheat air turbine unit with tangential volute intake and lateral exhaust has a medium-pressure intake port 20 and a medium-pressure exhaust port 21 on the lower side of the medium-pressure inner cylinder, and adopts a bottom-intake and bottom-exhaust method for gas circulation.

[0030] 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 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.

[0031] 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 below the horizontal center plane through a positioning center beam; The high and medium pressure cylinder comprises 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 mode and a first-stage horizontal stationary blade is arranged in the high pressure inner cylinder air intake passage. The high pressure air intake ports on both sides of the high pressure inner cylinder are respectively 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. The low-pressure inner cylinder is divided into two oppositely arranged flow channels in a double-dividing form.

2. A secondary reheat air turbine unit with tangential volute intake and lateral exhaust according to claim 1, characterized in that: A thrust bearing is arranged 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.

3. A 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 pre-buried in the foundation, forming an absolute dead point of the unit.

4. A 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 a 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. A 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. A 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. A 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-divided flow structure, and a low-pressure air inlet and a low-pressure air outlet are provided on the low-pressure inner cylinder, and air is introduced through the lower half of the volute and exhausted sideways.

8. A secondary reheat air turbine unit with tangential volute intake and lateral exhaust according to claim 1, characterized in that: The low-pressure rotor side is connected to the generator through a coupling gasket and connecting bolts.

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