A high-pressure module for a high-temperature high-pressure once-reheat 660MW air turbine

Abstract

This invention relates to a high-pressure module for a 660MW air turbine with high temperature and high pressure and single reheat operation. The invention addresses the problems of low intake efficiency, poor injection adjustment accuracy, axial thrust imbalance, and insufficient operational reliability in existing high-pressure modules. It employs a symmetrical dual-flow structure, with the cylinder and rotor of the flow section symmetrically arranged to achieve axial thrust self-balancing, significantly reducing thrust bearing load and improving unit operational stability and safety. The high-pressure inner cylinder uses a tangential volute + dual-intake structure, combined with a dual-flow + single injection integrated structure. The volute intake significantly reduces intake eddies and total pressure loss, improving flow efficiency. The high-pressure outer cylinder is equipped with a two-stage independent injection system, enabling precise staged injection to adapt to varying flow and pressure requirements. This invention belongs to the field of air turbine technology.

Description

Technical Field

[0001] This invention relates to a high-voltage module, specifically a high-voltage module for a 660MW high-temperature, high-pressure, single-reheat air turbine, belonging to the field of air turbine technology. Background Technology

[0002] The high-pressure module, also known as the high-pressure cylinder module, is the core working unit in modern modular air turbine design, responsible for handling the highest pressure and highest temperature intake air. Existing high-pressure modules exhibit the following problems during operation:

[0003] 1. Asymmetrical intake structure leads to severe flow field distortion and low aerodynamic efficiency:

[0004] Traditional high-pressure internal cylinders mostly adopt a single-sided air intake and a non-volute flow guide structure, resulting in strong intake vortices, uneven flow field distribution, large total pressure loss, and low flow efficiency. Air replenishment often uses bent pipe injection or external pipe connection, which results in poor flow channel smoothness and weak sealing structure. Under high temperature and high pressure conditions, leakage and deformation are prone to occur, making it impossible to balance compactness and reliability.

[0005] Second, the single-level air supply system results in poor adjustment accuracy and wide load adaptability.

[0006] Existing air injection systems are mostly single-stage centralized air injection systems, lacking clear functional division between internal and external cylinder air injection, resulting in uneven airflow distribution and large pressure pulsations. The air injection ports are not symmetrically designed or differentiated between upper and lower sections, making it difficult to accurately match the air injection flow rate and pressure with the main airflow under varying operating conditions. This prevents the implementation of staged, zoned, and controllable air injection, and results in insufficient wide-load adjustment capability. Furthermore, the cylinders lack multi-chamber separation designs, leading to significant inter-stage gas leakage and flow channel interference, further reducing efficiency and stability.

[0007] Third, the asymmetric flow path structure causes an imbalance in axial thrust and insufficient safety margin.

[0008] Conventional high-voltage modules are mainly based on a single-flow structure with large axial thrust, which is mainly passively offset by thrust bearings. This results in high bearing load, rapid wear, short service life, and the risk of dynamic and static collision and rubbing under extreme operating conditions.

[0009] In summary, how to propose a novel high-voltage module to address the aforementioned technical problems has become a pressing issue for those skilled in the art. Summary of the Invention

[0010] In view of the shortcomings of the prior art, the present invention provides a high-voltage module for a 660MW air turbine with high temperature and high pressure and single reheat.

[0011] The technical solution of the present invention is: a high-pressure module for a 660MW air turbine with high temperature and high pressure reheat, comprising a front bearing housing, a rear bearing housing, a high-pressure outer cylinder, a high-pressure inner cylinder, a high-pressure reverse partition sleeve, a high-pressure forward partition sleeve, and a primary air injection pipe.

[0012] The front bearing housing, high-pressure outer cylinder, and rear bearing housing are arranged coaxially in sequence. The high-pressure outer cylinder has a two-stage air injection port and an exhaust port.

[0013] The high-pressure reverse baffle sleeve, the high-pressure inner cylinder, and the high-pressure forward baffle sleeve are arranged coaxially in the high-pressure outer cylinder, and the high-pressure reverse baffle sleeve and the high-pressure forward baffle sleeve are arranged symmetrically with respect to the high-pressure inner cylinder. The first-stage air injection pipe passes through the high-pressure outer cylinder and connects to the high-pressure inner cylinder.

[0014] Several stages of high-pressure reverse blades are installed on the high-pressure reverse baffle sleeve, and several stages of high-pressure forward blades are installed on the high-pressure forward baffle sleeve.

[0015] Furthermore, the intake structure of the high-pressure inner cylinder is a tangential volute structure, and two tangential intake ports are opened on the tangential volute structure in a circumferential array.

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

[0017] 1. The high-pressure inner cylinder 4 adopts a tangential volute + dual-intake structure, combined with a dual-flow + primary air injection integrated structure. The volute intake significantly reduces intake turbulence and total pressure loss, improving flow efficiency. The primary air injection adopts a direct-drive air injection pipe scheme, which ensures smooth flow, compact structure, and reliable sealing, while taking into account both strength and heat exchange requirements under high-temperature and high-pressure conditions.

[0018] 2. The high-pressure outer cylinder 3 is equipped with a two-stage independent air replenishment system: it can achieve precise air replenishment in stages and adapt to the requirements of flow rate and pressure matching under different working conditions.

[0019] 3. The present invention adopts a symmetrical double-flow structure, and the cylinder and rotor of the flow section are symmetrically arranged to achieve axial thrust self-balancing, which greatly reduces the load on the thrust bearing and improves the stability and safety of the unit operation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the longitudinal section of the present invention;

[0021] Figure 2 This is a schematic diagram of the cross-section of the air intake structure of the high-pressure inner cylinder 4 of the present invention.

[0022] In the diagram: 1. Front bearing housing; 2. Rear bearing housing; 3. High-pressure outer cylinder; 4. High-pressure inner cylinder; 5. High-pressure reverse diaphragm sleeve; 6. High-pressure forward diaphragm sleeve; 7. High-pressure reverse blade; 8. High-pressure forward blade; 9. First-stage air supply pipe; 10. Second-stage air supply interface. Detailed Implementation

[0023] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments.

[0024] Specific implementation method one: Combining Figures 1 to 2 This embodiment describes a high-pressure module for a 660MW air turbine with high temperature and high pressure reheat, comprising a front bearing housing 1, a rear bearing housing 2, a high-pressure outer cylinder 3, a high-pressure inner cylinder 4, a high-pressure reverse partition sleeve 5, a high-pressure forward partition sleeve 6, and a primary air supply pipe 9.

[0025] The front bearing housing 1, the high-pressure outer cylinder 3, and the rear bearing housing 2 are arranged coaxially in sequence. Preferably, the front bearing housing 1 and the rear bearing housing 2 are both connected to the high-pressure outer cylinder 3 through a centering beam, and both ends of the high-pressure outer cylinder 3 are supported on the front bearing housing 1 and the rear bearing housing 2 by lower cylinder claws.

[0026] The high-pressure outer cylinder 3 has a secondary air injection port 10 and an exhaust port, and both the secondary air injection port 10 and the exhaust port are located at the lower part of the high-pressure outer cylinder 3.

[0027] The high-pressure reverse baffle sleeve 5, the high-pressure inner cylinder 4, and the high-pressure forward baffle sleeve 6 are arranged coaxially in the high-pressure outer cylinder 3, and the high-pressure reverse baffle sleeve 5 and the high-pressure forward baffle sleeve 6 are arranged symmetrically with respect to the high-pressure inner cylinder 4.

[0028] The primary air supply pipe 9 is located on the upper part of the high-pressure outer cylinder 3, and after passing through the high-pressure outer cylinder 3, the primary air supply pipe 9 connects to the high-pressure inner cylinder 4.

[0029] Several stages of high-pressure reverse blades 7 are installed on the high-pressure reverse baffle sleeve 5, and several stages of high-pressure forward blades 8 are installed on the high-pressure forward baffle sleeve 6.

[0030] Specific Implementation Method Two: Combining Figures 1 to 2 This embodiment describes a high-pressure reverse blade 7 with 12 stages.

[0031] Furthermore, the high-pressure positive blade 8 has 12 stages.

[0032] Furthermore, the intake structure of the high-pressure inner cylinder 4 is a tangential volute structure, and two tangential intake ports are opened on the tangential volute structure in a circumferential array. Preferably, the tangential intake ports are located at the center of the flow length direction of the high-pressure inner cylinder 4. This setting eliminates the traditional single-sided asymmetrical intake form, so that the airflow enters the flow section on both sides evenly along the axial direction, making the airflow distribution uniform and the pressure pulsation small.

[0033] Furthermore, there are two primary air supply pipes 9. Preferably, one primary air supply pipe 9 is arranged after the 5th stage of the high-pressure reverse blade 7, and the other primary air supply pipe 9 is arranged after the 5th stage of the high-pressure forward blade 8. With this arrangement, the primary air supply directly enters the flow path of the high-pressure inner cylinder 4.

[0034] Furthermore, the number of exhaust ports is four.

[0035] Furthermore, there are two secondary air supply ports 10. Preferably, one secondary air supply port 10 is arranged after the 8th stage of the high-pressure reverse blade 7, and the other secondary air supply port 10 is arranged after the 8th stage of the high-pressure forward blade 8. With this arrangement, the secondary air supply enters the interlayer cavity between the high-pressure outer cylinder 3 and the high-pressure inner cylinder 4, the interlayer cavity between the high-pressure outer cylinder 3 and the high-pressure reverse baffle sleeve 5, and the interlayer cavity between the high-pressure outer cylinder 3 and the high-pressure forward baffle sleeve 6. Then, it enters the last 4 stages of flow through the preset flow channel (the first stage is near the center of the flow length direction), realizing the pressure balance of the flow in the later stage and the sealing air supply between stages.

[0036] This graded and zoned controllable two-stage air replenishment system greatly improves the unit's wide load adjustment capability. Combined with the aforementioned multi-layered cavity separation structure, it can achieve graded and precise air replenishment, adapt to the requirements of variable operating conditions for flow rate and pressure matching, and significantly reduce flow field distortion and total pressure loss.

[0037] Through the above structural design, the dual-flow structure of the high-pressure inner cylinder 4, the tangential volute air intake, and the air replenishment structure are reasonably combined, which enhances the aerodynamic performance and variable working condition capability.

[0038] The other components and connections are the same as in Specific Implementation Method 1.

[0039] Working principle

[0040] The flow passage section is symmetrically arranged with tangential air inlets on the left and right sides, forming a dual-flow structure, which reduces axial thrust from the source. The flow passage section forms a partition structure of multiple chambers such as the inner cylinder cavity, the inner and outer cylinder sandwich cavity, and the diaphragm sleeve cavity, which suppresses interstage gas leakage and airflow interference, achieves active balance of axial thrust, reduces bearing load and the risk of dynamic and static rubbing, and improves the long-term operational reliability of the unit.

[0041] High-temperature and high-pressure (357.76℃, maximum 15.24MPa) compressed air enters through two tangential inlets, flows symmetrically into both sides to perform work, and the compressed air after performing work is discharged through the exhaust port.

[0042] The present invention has been disclosed above with reference to preferred embodiments, but it is not intended to limit the present invention. Any simple modifications, equivalent changes and alterations made by those skilled in the art to the above embodiments without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A high-voltage module for a 660MW air turbine with high temperature and high pressure and single reheat, characterized in that: It includes a front bearing housing (1), a rear bearing housing (2), a high-pressure outer cylinder (3), a high-pressure inner cylinder (4), a high-pressure reverse partition sleeve (5), a high-pressure forward partition sleeve (6), and a primary air supply pipe (9). The front bearing housing (1), the high-pressure outer cylinder (3) and the rear bearing housing (2) are arranged coaxially in sequence. The high-pressure outer cylinder (3) has a secondary air injection port (10) and an exhaust port. The high-pressure reverse baffle sleeve (5), the high-pressure inner cylinder (4) and the high-pressure forward baffle sleeve (6) are arranged coaxially in the high-pressure outer cylinder (3) in sequence, and the high-pressure reverse baffle sleeve (5) and the high-pressure forward baffle sleeve (6) are arranged symmetrically with respect to the high-pressure inner cylinder (4). The first-stage air injection pipe (9) passes through the high-pressure outer cylinder (3) and connects to the high-pressure inner cylinder (4). Several high-pressure reverse blades (7) are installed on the high-pressure reverse baffle sleeve (5), and several high-pressure forward blades (8) are installed on the high-pressure forward baffle sleeve (6).

2. The high-voltage module for a 660MW air turbine with high temperature and high pressure reheat as described in claim 1, characterized in that: The high-pressure reverse blade (7) has 12 stages.

3. The high-voltage module for a 660MW air turbine with high temperature and high pressure reheat as described in claim 2, characterized in that: The high-pressure positive blade (8) has 12 stages.

4. The high-voltage module for a 660MW air turbine with high temperature and high pressure reheat as described in claim 3, characterized in that: The intake structure of the high-pressure inner cylinder (4) is a tangential volute structure, and two tangential intake ports are opened on the tangential volute structure in a circular array.

5. A high-voltage module for a 660MW air turbine with high temperature and high pressure single reheat as described in claim 4, characterized in that: The number of the primary gas supply intubation tubes (9) is two.

6. The high-voltage module for a 660MW air turbine with high temperature and high pressure reheat as described in claim 5, characterized in that: The number of the secondary air supply ports (10) is two, and the number of exhaust ports is four.

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