Supercritical carbon dioxide impeller clearance adjusting mechanism

Abstract

The invention discloses a supercritical carbon dioxide impeller clearance adjusting mechanism, and belongs to the technical field of thermal power generation equipment. A casing is mounted on a volute, and an adjusting rod is fixedly connected to the casing; an end cover and a bearing seat are respectively mounted on two sides of the volute; an impeller rotor is mounted in the bearing seat; an opening is formed in the end cover and used for allowing the adjusting rod to pass through; the end, away from the casing, of the adjusting rod is provided with threads, and the adjusting rod is in threaded connection with a square nut through the threads. The gap between the impeller rotor and the casing can be effectively adjusted, the collision and abrasion risk of the impeller rotor and the casing is reduced, and the efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal power generation equipment, and in particular relates to a supercritical carbon dioxide impeller clearance adjustment mechanism. Background Art

[0002] As a highly efficient power cycle working fluid, supercritical carbon dioxide (SCO2) has unique physical properties of high density and low viscosity, with a critical temperature of 31.1°C and a critical pressure of 7.38MPa. Compared with traditional power cycle working fluids such as water vapor, the critical conditions of supercritical carbon dioxide are easier to achieve, which means that under the same working conditions, the SCO2 power cycle system has more relaxed requirements on device materials, thereby reducing the manufacturing cost and maintenance difficulty of the equipment. In addition, SCO2 is colorless, non-toxic, odorless, has stable chemical properties, is highly safe to use, and has a low cost, making it an ideal choice for large-scale applications.

[0003] Supercritical carbon dioxide turbomachinery, that is, turbomachinery using SCO2 as the working fluid, mainly includes key components such as impeller rotor, casing, volute, bearing seat, etc. Compared with steam turbomachinery, SCO2 impeller machinery has a simpler design, a more compact structure, a higher speed of impeller rotor, and better aerodynamic efficiency. When designing this type of impeller machinery, in order to pursue a compact structure and efficient aerodynamic performance, the impeller rotor is usually designed as an ultra-high-speed rotor. In order to prevent the impeller from being damaged due to excessive centrifugal force under high-speed rotation, the impeller usually adopts a semi-open design, which helps to disperse stress and reduce material fatigue damage.

[0004] However, in order to maximize aerodynamic efficiency, the dynamic and static clearance between the impeller and the casing is designed to be extremely small. Although this design improves efficiency, it also brings some challenges. The most important challenges include the risk of friction between the impeller and the casing, and the problem that aerodynamic efficiency will drop significantly once the clearance becomes larger.

[0005] In order to solve the above problems, the present invention provides a supercritical carbon dioxide impeller clearance adjustment mechanism. Summary of the invention

[0006] The invention provides a supercritical carbon dioxide impeller clearance adjustment mechanism, which solves the shortcomings of the existing supercritical carbon dioxide impeller machinery, such as the impeller rubbing against the casing and the reduced aerodynamic efficiency after the clearance becomes larger.

[0007] The present invention provides a supercritical carbon dioxide impeller clearance adjustment mechanism, which adopts the following technical solutions: A casing, wherein the casing is mounted on the volute, the casing and the volute are clearance-matched, and an adjusting rod is fixedly connected to the casing; End covers and bearing seats are respectively installed on both sides of the volute; An impeller rotor is installed inside the bearing seat; The end cover is provided with an opening for accommodating the passage of the adjusting rod; A thread is arranged on one end of the adjusting rod away from the receiver, and the adjusting rod is screwed with a square nut through the thread.

[0008] Furthermore, there are multiple adjusting rods, which are evenly distributed on the casing along the circumference of the impeller rotor.

[0009] Furthermore, a sealing ring is installed on the outer ring of the casing.

[0010] Furthermore, a wheel cover is installed on the outer side of the end cover; and a sealing cover is installed on the end surface of the wheel cover.

[0011] Furthermore, the wheel cover is provided with a second opening for accommodating the square nut.

[0012] Furthermore, a circular convex edge is provided on one side of the square nut close to the end cover; a circular groove is also provided in the wheel cover; and the circular convex edge and the circular groove match each other.

[0013] Furthermore, the adjusting rod and the casing are connected by welding, riveting or threaded connection.

[0014] Furthermore, the casing is an integrated structure.

[0015] Furthermore, the end cover is mounted on the volute by bolts; the wheel cover and the end cover are fixed by bolts; and the cover and the wheel cover are fixed by bolts.

[0016] Furthermore, the impeller rotor is an integrated structure of the impeller main shaft, and a first-step step shaft and a second-step step shaft are sequentially arranged from the back of the impeller; the diameter of the first-step step shaft is larger than the diameter of the second-step step shaft; two bearings are mounted on the second-step step shaft; comb teeth are arranged inside the bearing seat at the position of the first-step step shaft for sealing.

[0017] Beneficial effects of the present invention: 1. The present invention uses a wheel cover and an end cover to limit the axial movement of the square nut. Rotating the square nut can realize the axial movement of the casing and adjust the gap between the casing and the impeller, effectively avoiding the disadvantages of friction between the impeller and the casing and reduced aerodynamic efficiency after the gap becomes larger.

[0018] 2. The present invention adopts square nuts, which is convenient for designing special tools and can transmit large torque.

[0019] 3. In the present application, the casing and the volute are clearance-matched, which can ensure that the casing does not get stuck when moving axially. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] For ease of explanation, the present invention is described in detail with reference to the following specific implementations and the accompanying drawings.

[0021] Figure 1 It is a cross-sectional view of the overall structure of the present invention; Figure 2 It is a schematic diagram of the distribution of the adjustment rods of the present invention on the receiver; Figure 3 It is a schematic diagram of the square nut structure of the present invention.

[0022] In the figure: 1. casing; 2. adjusting rod; 3. sealing cover; 4. square nut; 5. wheel cover; 6. end cover; 7. volute; 8. sealing ring; 9. impeller rotor; 10. bearing seat; 11. first-step stepped shaft; 12. second-step stepped shaft; 13. bearing; 14. comb teeth. DETAILED DESCRIPTION

[0023] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments; in the following description, specific details such as specific configurations and components are provided only to help fully understand the embodiments of the present invention. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, for the sake of clarity and brevity, the description of known functions and structures is omitted.

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0025] like Figure 1-3 As shown, a specific embodiment of a supercritical carbon dioxide impeller gap adjustment mechanism is provided, comprising: a casing 1 installed on a volute 7, the casing 1 and the volute 7 are gap-matched, an adjusting rod 2 is fixedly connected to the casing 1, end covers 6 and a bearing seat 10 are respectively installed on both sides of the volute 7, an impeller rotor 9 is installed inside the bearing seat 10, an opening is provided on the end cover 6 to accommodate the passage of the adjusting rod 2, so that the adjusting rod 2 can be operated externally without disassembling the equipment, thereby conveniently adjusting the gap between the impeller rotor 9 and the casing 1, a thread is provided on the end of the adjusting rod 2 away from the casing 1, and the adjusting rod 2 is screwed with a square nut 4 through the thread.

[0026] Specifically, the square nut 4 has a square shape on the outside and can be rotated using a square hole wrench or a special tool, thereby transmitting a large torque.

[0027] Specifically, the casing 1 and the volute 7 are clearance-matched, which can ensure that the casing 1 does not get stuck when moving axially.

[0028] Specifically, an adjusting rod 2 is provided on the casing 1, and the adjusting rod 2 extends out of the casing through the opening of the end cover 6. At the same time, a square nut 4 is arranged on the head of the adjusting rod 2. By rotating the square nut 4, the casing 1 can be moved axially, and the gap between the impeller rotor 9 and the casing 1 can be accurately adjusted, which effectively avoids the shortcomings of friction between the impeller rotor 9 and the casing 1, and reduced aerodynamic efficiency when the gap becomes larger, and helps to optimize the operating performance of the equipment.

[0029] Specifically, Figure 2 As shown, there are multiple adjusting rods 2 , which are evenly distributed on the casing 1 along the circumference of the impeller rotor 9 .

[0030] Specifically, the even distribution of multiple adjusting rods 2 can ensure that the clearance adjustment force between the impeller rotor 9 and the casing 1 is evenly applied, avoiding impeller deflection or imbalance caused by uneven adjustment force, and can effectively solve the problem that the casing 1 is stuck and unable to move axially when the connection between a single adjusting rod 2 and the casing 1 is deformed, so that the clearance between the casing 1 and the impeller can be adjusted online and is not easy to get stuck. It has the advantages of simple structure and no need to disassemble the machine for adjustment.

[0031] In other preferred embodiments, a sealing ring 8 is installed on the outer ring of the casing 1 .

[0032] Specifically, the sealing ring 8 is provided to ensure that the fluid does not leak from the gap between the volute 7 and the casing 1 during the adjustment process, thereby maintaining efficient operation of the system.

[0033] In other preferred embodiments, a wheel cover 5 is installed on the outside of the end cover 6, and a sealing cover 3 is installed on the end face of the wheel cover 5, which can prevent gas from leaking from the open hole gap of the end cover 6 corresponding to the adjusting rod 2, and can also protect the adjusting rod 2 and the square nut 4 from the influence of external impurities and maintain the stability of the adjusting mechanism.

[0034] Specifically, the wheel cover 5 is provided with a second opening for accommodating the square nut 4 , so as to facilitate the use of a tool to rotate the square nut 4 .

[0035] Specifically, Figure 1 and Figure 3 As shown, a circular convex edge is provided on one side of the square nut 4 close to the end cover 6; a circular groove is also provided in the wheel cover 5; the circular convex edge and the circular groove cooperate with each other to limit the axial movement of the square nut 4, so when the square nut 4 rotates, the corresponding adjusting rod 2 moves axially under the action of the thread, thereby driving the casing 1 to move axially, enhancing the stability between the square nut 4 and the wheel cover 5, and preventing the adjusting rod 2 from loosening during the adjustment process.

[0036] In other preferred embodiments, the adjusting rod 2 and the casing 1 are connected by welding, riveting or threaded connection, and the most suitable connection method can be flexibly selected according to actual application requirements.

[0037] In other preferred embodiments, the casing 1 is an integrated structure, which simplifies the manufacturing process, reduces the number of parts, and improves the strength and rigidity of the overall structure.

[0038] In other preferred embodiments, the end cover 6 is mounted on the volute 7 by bolts; the wheel cover 5 and the end cover 6 are fixed by bolts; and the cover 3 and the wheel cover 5 are fixed by bolts.

[0039] Specifically, fast disassembly and reassembly can be achieved through bolt fixing, which is convenient for maintenance and overhaul of the equipment.

[0040] In other preferred embodiments, the impeller rotor 9 is an integrated structure of the impeller main shaft, and a first-step step shaft 11 and a second-step step shaft 12 are sequentially provided from the back of the impeller; the diameter of the first-step step shaft 11 is larger than the diameter of the second-step step shaft 12; two bearings 13 are mounted on the second-step step shaft 12; and comb teeth 14 are provided inside the bearing seat 10 at the position of the first-step step shaft 11 for sealing.

[0041] Specifically, the impeller rotor 9 is an integrated structure of the impeller main shaft, which provides higher structural strength and rigidity, can withstand the huge centrifugal force generated during high-speed rotation, and ensure the stable operation of the impeller.

[0042] Specifically, two bearings 13 are mounted on the second-step stepped shaft 12 . This design can provide better axial and radial support, reduce the load on the bearing, extend the service life of the bearing 13 , and reduce the risk of downtime due to bearing 13 failure.

[0043] Specifically, comb teeth 14 are provided at the first-step shaft 11 for sealing. This sealing structure can effectively prevent leakage of the working medium and improve the overall sealing performance of the system. At the same time, the design of sealing using comb teeth 14 is also convenient for maintenance and replacement.

[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] In the description of the present application, it should be understood that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0047] Those skilled in the art to which the present application belongs may make various modifications or additions to the described specific embodiments or replace them in a similar manner, but they will not deviate from the spirit of the present application or exceed the scope defined by the attached claims.

Claims

1. A supercritical carbon dioxide impeller clearance adjustment mechanism, characterized in that: include: A casing (1), the casing (1) being mounted on a volute (7), the casing (1) and the volute (7) being in clearance fit, and an adjusting rod (2) being fixedly connected to the casing (1); An end cover (6) and a bearing seat (10) are respectively mounted on both sides of the volute (7); An impeller rotor (9) is installed inside the bearing seat (10); The end cover (6) is provided with an opening for accommodating the passage of the adjustment rod (2); A thread is provided on one end of the adjusting rod (2) away from the casing (1), and the adjusting rod (2) is screwed with a square nut (4) via the thread.

2. A supercritical carbon dioxide impeller clearance adjustment mechanism according to claim 1, characterized in that: The regulating rods (2) are multiple in number and are evenly distributed on the casing (1) along the circumference of the impeller rotor (9).

3. A supercritical carbon dioxide impeller clearance adjustment mechanism according to claim 1, characterized in that: A sealing ring (8) is mounted on the outer ring of the casing (1).

4. The supercritical carbon dioxide impeller clearance adjustment mechanism according to claim 1, characterized in that: A wheel cover (5) is mounted on the outer side of the end cover (6); and a sealing cover (3) is mounted on the end surface of the wheel cover (5).

5. A supercritical carbon dioxide impeller clearance adjustment mechanism according to claim 4, characterized in that: The wheel cover (5) is provided with a second opening for accommodating the square nut (4).

6. A supercritical carbon dioxide impeller clearance adjustment mechanism according to claim 5, characterized in that: A circular convex edge is provided on one side of the square nut (4) close to the end cover (6); a circular groove is also provided in the wheel cover (5); the circular convex edge and the circular groove cooperate with each other.

7. The supercritical carbon dioxide impeller clearance adjustment mechanism according to claim 1, characterized in that: The adjusting rod (2) and the casing (1) are connected by welding, riveting or threaded connection.

8. The supercritical carbon dioxide impeller clearance adjustment mechanism according to claim 1, characterized in that: The casing (1) is an integrated structure.

9. The supercritical carbon dioxide impeller clearance adjustment mechanism according to claim 4, characterized in that: The end cover (6) is mounted on the volute (7) by means of bolts; the wheel cover (5) and the end cover (6) are fixed by means of bolts; and the cover (3) and the wheel cover (5) are fixed by means of bolts.

10. The supercritical carbon dioxide impeller clearance adjustment mechanism according to claim 1, characterized in that: The impeller rotor (9) is an integrated structure of the impeller main shaft, and is provided with a first-step stepped shaft (11) and a second-step stepped shaft (12) in sequence from the back of the impeller; the diameter of the first-step stepped shaft (11) is larger than the diameter of the second-step stepped shaft (12); two bearings (13) are mounted on the second-step stepped shaft (12); and comb teeth (14) are provided inside the bearing seat (10) at the position of the first-step stepped shaft (11) for sealing.

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