Primary double-suction, two-stage radial split centrifugal pump

Abstract

This utility model relates to the field of centrifugal pump technology, and in particular to a first-stage double-suction, two-stage radially split centrifugal pump. The pump body of this utility model is equipped with a suction cover and a discharge cover at both ends; a shaft is mounted through the suction cover, pump body, and discharge cover; both ends of the shaft are respectively mounted in bearing components; a first-stage impeller and a second-stage impeller are mounted on the shaft; the first-stage impeller's axial positioning on the shaft is limited by a limiting structure; a first-stage friction pair is assembled between the first-stage impeller and the pump body; a second-stage friction pair is assembled between the second-stage impeller and the pump body; the second-stage impeller is locked on the shaft outside the discharge cover by a locking nut, and is equipped with a hub-side secondary impeller inlet ring. The technical solution of this utility model solves the problems of insufficient reliability, large bearing vibration, large bearing temperature rise, and low efficiency that occur in existing technologies under high temperature, high pressure, and large pipe load conditions.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal pump technology, and in particular to a first-stage double-suction, two-stage radially split centrifugal pump. Background Technology

[0002] The first-stage double-suction, two-stage radially split pump is the BB2 type pump conforming to the latest version of API 610. This series of products features excellent product performance, reliable product quality, and the shortest maintenance cycle, with performance indicators reaching international advanced levels. In power plants, the first-stage double-suction, two-stage radially split pump is primarily used as a boiler feedwater booster pump. This pump mainly transports high-temperature hot water, placing high demands on its suction performance and operational stability, as the performance of this critical pump has a significant impact on the entire system.

[0003] BB2 products are generally used in high temperature, high pressure and large pipe load conditions. At present, ordinary BB2 products in China often have problems such as insufficient reliability, large bearing vibration, large bearing temperature rise and low efficiency when operating under harsh conditions. In addition, the pumps for key positions are mainly imported.

[0004] In view of the problems existing in the above-mentioned existing technologies, it is necessary to study and design a new type of first-stage double-suction, two-stage radial split centrifugal pump to overcome the problems existing in the existing technologies. Summary of the Invention

[0005] In response to the technical problems mentioned above, such as insufficient reliability, large bearing vibration, large bearing temperature rise, and low efficiency that occur under high temperature, high pressure, and large pipe load conditions, this paper provides a structurally safe, reliable, and efficient first-stage double-suction, two-stage radially split centrifugal pump; thereby enabling the pump to operate smoothly under various conditions such as high temperature and high pressure.

[0006] The technical means adopted in this utility model are as follows:

[0007] A first-stage double-suction, two-stage radially split centrifugal pump, including a pump body;

[0008] Furthermore, the pump body is a one-piece cast structure that integrates suction and discharge functions;

[0009] Furthermore, the pump body is equipped with positioning pin holes and guide pin holes, which can constrain the pump's axial expansion under high-temperature conditions.

[0010] Furthermore, the pump body is equipped with a suction cover and a discharge cover at both ends, respectively;

[0011] Furthermore, shafts are mounted through the suction cover, pump body, and discharge cover;

[0012] Furthermore, both ends of the shaft are respectively assembled into bearing components;

[0013] Furthermore, the two bearing components are fixedly connected to the suction cover and the discharge cover, respectively;

[0014] Furthermore, a primary impeller and a secondary impeller are mounted on the shaft;

[0015] Furthermore, the first-stage impeller is restricted in its axial positioning on the shaft by a limiting structure;

[0016] Furthermore, a primary friction pair is assembled between the primary impeller and the pump body;

[0017] Furthermore, a secondary friction pair is assembled between the secondary impeller and the pump body;

[0018] Furthermore, the secondary impeller is located on a shaft outside the discharge cover side and is locked by a lock nut, and is equipped with a hub-side secondary impeller inlet ring.

[0019] Furthermore, the suction cap contains half of the suction water force;

[0020] Furthermore, the inhalation cap adopts a double static seal structure;

[0021] Furthermore, the suction cover adopts an integrated structure with the bearing housing bracket, and the bearing housing bracket is connected to the bearing components.

[0022] Furthermore, the discharge cover has an independent large-volume balance chamber structure;

[0023] Furthermore, the discharge cover adopts an integrated structure with the bearing housing bracket, and the bearing housing bracket is connected to the bearing components.

[0024] Furthermore, the first-stage impeller adopts a double-suction structure, which can increase the pump's suction performance and simultaneously balance the axial force.

[0025] Furthermore, the secondary impeller adopts a single-suction structure;

[0026] Furthermore, the secondary impeller has the same diameter as the primary impeller;

[0027] Furthermore, the secondary impeller mouth ring adopts a high-low structure, which can achieve axial force balance;

[0028] Furthermore, the secondary impeller's inner bore adopts a tapered shape, which facilitates the installation and disassembly of the impeller.

[0029] Furthermore, an interstage bushing and interstage liner structure is adopted between the first-stage impeller and the second-stage impeller to reduce interstage leakage;

[0030] Furthermore, the interstage bushings and interstage sleeves are secured with screws to prevent axial movement.

[0031] Furthermore, the first-stage friction pair includes: a first-stage body cover ring and a first-stage impeller ring;

[0032] Furthermore, the first-stage body cover ring is assembled onto the pump body;

[0033] Furthermore, the first-stage impeller mouth ring is assembled on the first-stage impeller;

[0034] Furthermore, the first-stage body cover ring and the first-stage impeller ring are structures that can be disassembled and replaced separately.

[0035] Furthermore, the secondary friction pair includes: a secondary body cover ring and a secondary impeller ring;

[0036] Furthermore, the secondary body cover ring is assembled onto the pump body;

[0037] Furthermore, the secondary impeller mouth ring is assembled on the secondary impeller;

[0038] Furthermore, the secondary body cover ring and the secondary impeller ring are structures that can be disassembled and replaced separately.

[0039] Furthermore, the limiting structure includes: a split retaining ring and a retaining sleeve;

[0040] Furthermore, a split retaining ring is installed on the shaft outside the first-stage impeller to restrict the axial movement of the first-stage impeller;

[0041] Furthermore, a retaining sleeve is provided on the outside of the split retaining ring, which restricts the separation of the split retaining ring;

[0042] Furthermore, the fixing sleeve is fixed to the shaft to fix and limit the half-clamp ring, while realizing the axial positioning function of the first-stage impeller.

[0043] Furthermore, the bearing components adopt a rolling bearing type structure, and are equipped with an internal fan, oil ring lubrication, and oil mist lubrication to effectively cool the bearing temperature and ensure the service life of the bearing.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] 1. The first-stage double-suction, two-stage radially split centrifugal pump provided by this utility model integrates suction and discharge functions into one pump body, and is equipped with positioning pins and guide pin holes at the bottom, which is suitable for limiting the radial expansion of the pump under high temperature conditions.

[0046] 2. The first-stage double-suction, two-stage radial split centrifugal pump provided by this utility model has a suction cover that includes suction hydraulics and is integrated with the bracket. It has a compact structure, reduces the number of connecting fasteners and machining surfaces, thereby reducing costs and simplifying machining and assembly.

[0047] 3. The first-stage double-suction, double-stage radial split centrifugal pump provided by this utility model has an independent pressure balance design for the discharge cover, and adopts an integrated design with the bracket, which has a compact structure, reduces the number of connecting fasteners and the number of machining surfaces, thereby reducing costs and reducing the difficulty of processing and assembly.

[0048] 4. The first-stage double-suction, two-stage radially split centrifugal pump provided by this utility model has a first-stage impeller with a double-suction structure, which can increase the pump's suction performance and at the same time self-balance axial force.

[0049] 5. The first-stage double-suction, two-stage radially split centrifugal pump provided by this utility model has a single-suction secondary impeller and a tapered hole design for the impeller mounting inner hole, which facilitates on-site disassembly and installation.

[0050] 6. The first-stage double-suction, two-stage radially split centrifugal pump provided by this utility model has all port rings with a detachable structure, which is convenient for on-site replacement;

[0051] 7. The first-stage double-suction, two-stage radially split centrifugal pump provided by this utility model has an interstage bushing and an interstage bushing with throttling function between the first-stage impeller and the second-stage impeller to reduce interstage leakage, and uses screw limit to prevent axial movement.

[0052] 8. The first-stage double-suction, two-stage radially split centrifugal pump provided by this utility model uses a fixed sleeve and split half-clamping ring structure for axial positioning of the first-stage impeller.

[0053] In summary, the technical solution of this utility model solves the problems of insufficient reliability, large bearing vibration, large bearing temperature rise, and low efficiency that occur under high temperature, high pressure, and large pipe load conditions in the prior art. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of the split structure of this utility model.

[0056] Figure 2 This is a schematic diagram of the pump body of this utility model.

[0057] Figure 3 This is a schematic diagram of the inhalation cap of this utility model.

[0058] Figure 4 This is a schematic diagram of the structure of the discharge cover of this utility model.

[0059] Figure 5 This is a schematic diagram of the structure of the first-stage impeller of this utility model.

[0060] Figure 6 This is a schematic diagram of the secondary impeller structure of this utility model.

[0061] Figure 7 This is a schematic diagram of the mouth ring of this utility model.

[0062] Figure 8 This is a schematic diagram of the structure of the interstage bushing and bushing of this utility model.

[0063] Figure 9 This is a schematic diagram of the structure of the fixing sleeve and the split retaining ring of this utility model.

[0064] In the diagram: 1. Pump body; 2. Suction cover; 3. Hub-side secondary impeller inlet ring; 4. Interstage bushing; 5. Half-clamp ring; 6. Interstage bushing; 7. Discharge cover; 8. Primary impeller; 9. Secondary impeller; 10. Fixing sleeve; 11. Shaft; 12. Primary body cover inlet ring; 13. Primary impeller inlet ring; 14. Secondary body cover inlet ring; 15. Secondary impeller inlet ring; 16. Locking nut; 17. Bearing assembly. Detailed Implementation

[0065] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0066] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0067] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0068] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0069] In the description of this utility model, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0070] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0071] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0072] like Figure 1 , 2 As shown, this utility model provides a first-stage double-suction, two-stage radially split centrifugal pump, including a pump body 1; the pump body 1 is an integrally cast structure integrating suction and discharge functions; a suction cover 2 and a discharge cover 7 are respectively mounted on both ends of the pump body 1; a shaft 11 is mounted through the suction cover 2, the pump body 1, and the discharge cover 7; both ends of the shaft 11 are respectively mounted in bearing components 17; the two bearing components 17 are respectively fixedly connected to the suction cover 2 and the discharge cover 7; a first-stage impeller 8 and a second-stage impeller 9 are mounted on the shaft 11; the first-stage impeller 8 is axially positioned on the shaft 11 by a limiting structure; a first-stage friction pair is assembled between the first-stage impeller 8 and the pump body 1; a second-stage friction pair is assembled between the second-stage impeller 9 and the pump body 1; the second-stage impeller 9 is locked on the shaft 11 outside the discharge cover 7 by a locking nut 16, and is equipped with a hub-side second-stage impeller inlet ring 3.

[0073] like Figure 2 As shown, the suction cover 2 contains half of the water suction power; the suction cover 2 adopts a double static sealing structure; the suction cover 2 adopts an integrated structure with the bearing housing bracket, and the bearing housing bracket is connected to the bearing component 17.

[0074] like Figure 4 As shown, the discharge cover 7 has an independent large-volume balance chamber structure; the discharge cover 7 adopts an integrated structure with the bearing housing bracket, and the bearing housing bracket is connected to the bearing component 17.

[0075] like Figure 5 As shown, the first-stage impeller 8 adopts a double-suction structure, which can increase the pump's suction performance and at the same time self-balance the axial force.

[0076] like Figure 6 As shown, the secondary impeller 9 adopts a single-suction structure; the secondary impeller 9 has the same diameter as the primary impeller 8; the inlet ring of the secondary impeller 9 adopts a high-low structure, which can achieve the balance of axial force; the inner hole of the secondary impeller 9 adopts a tapered hole form, which facilitates the installation and disassembly of the impeller.

[0077] like Figure 8 As shown, the first-stage impeller 8 and the second-stage impeller 9 are connected by an interstage bushing 4 and an interstage bushing 6 to reduce interstage leakage; the interstage bushing 4 and the interstage bushing 6 are limited by screws to prevent axial movement.

[0078] like Figure 7 As shown, the primary friction pair includes: a primary body cover ring 12 and a primary impeller ring 13; the primary body cover ring 12 is mounted on the pump body 1; the primary impeller ring 13 is mounted on the primary impeller 8; the primary body cover ring 12 and the primary impeller ring 13 are structures that can be disassembled and replaced separately.

[0079] like Figure 7As shown, the secondary friction pair includes: a secondary body cover ring 14 and a secondary impeller ring 15; the secondary body cover ring 14 is mounted on the pump body 1; the secondary impeller ring 15 is mounted on the secondary impeller 9; the secondary body cover ring 14 and the secondary impeller ring 15 are structures that can be disassembled and replaced separately.

[0080] like Figure 9 As shown, the limiting structure includes: a split retaining ring 5 and a fixing sleeve 10; the split retaining ring 5 is mounted on the shaft 11 on the outside of the first-stage impeller 8 to restrict the axial movement of the first-stage impeller 8; the fixing sleeve 10 is provided on the outside of the split retaining ring 5 to restrict the separation of the split retaining ring 5; the fixing sleeve 10 is fixed on the shaft 2 to fix and limit the split retaining ring 5, and at the same time realize the axial positioning function of the first-stage impeller 8.

[0081] The bearing component 17 adopts a rolling bearing type structure and is equipped with an internal fan, oil ring lubrication and oil mist lubrication to effectively cool the bearing temperature and ensure the service life of the bearing.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A first-stage double-suction, two-stage radially split centrifugal pump, characterized in that: The first-stage double-suction, two-stage radially split centrifugal pump includes a pump body (1); The pump body (1) is an integrally cast structure that integrates suction and discharge functions; The pump body (1) is equipped with a suction cover (2) and a discharge cover (7) at both ends; A shaft (11) is mounted through the suction cover (2), pump body (1) and discharge cover (7); The two ends of the shaft (11) are respectively assembled in the bearing component (17); The two bearing components (17) are fixedly connected to the suction cover (2) and the discharge cover (7) respectively; The shaft (11) is equipped with a first-stage impeller (8) and a second-stage impeller (9); The first-stage impeller (8) is restricted in its axial positioning on the shaft (11) by a limiting structure; A primary friction pair is assembled between the primary impeller (8) and the pump body (1); A secondary friction pair is assembled between the secondary impeller (9) and the pump body (1); The secondary impeller (9) is located on a shaft (11) outside the discharge cover (7) and is locked by a lock nut (16), and is equipped with a hub-side secondary impeller inlet ring (3).

2. The first-stage double-suction, two-stage radially split centrifugal pump according to claim 1, characterized in that: The suction cap (2) comprises half of the suction water; The inhalation cap (2) adopts a double static sealing structure; The suction cover (2) adopts an integrated structure with the bearing housing bracket, and the bearing housing bracket is connected to the bearing component (17).

3. The first-stage double-suction, two-stage radially split centrifugal pump according to claim 1, characterized in that: The discharge cover (7) has an independent large-volume balance chamber structure; The discharge cover (7) adopts an integrated structure with the bearing housing bracket, and the bearing housing bracket is connected to the bearing component (17).

4. The first-stage double-suction, two-stage radially split centrifugal pump according to claim 1, characterized in that: The first-stage impeller (8) adopts a double-suction structure, which can increase the pump's suction performance and balance the axial force.

5. The first-stage double-suction, two-stage radially split centrifugal pump according to claim 1, characterized in that: The secondary impeller (9) adopts a single-suction structure; The secondary impeller (9) has the same diameter as the primary impeller (8); The secondary impeller (9) mouth ring adopts a high and low structure, which can achieve axial force balance; The inner hole of the secondary impeller (9) adopts a tapered hole form, which facilitates the installation and disassembly of the impeller.

6. The first-stage double-suction, two-stage radially split centrifugal pump according to claim 5, characterized in that: The first-stage impeller (8) and the second-stage impeller (9) are connected by an interstage bushing (4) and an interstage bushing (6) to reduce interstage leakage. The interstage bushing (4) and interstage bushing (6) are limited by screws to prevent axial movement.

7. The first-stage double-suction, two-stage radially split centrifugal pump according to claim 1, characterized in that: The first-stage friction pair includes: a first-stage body cover ring (12) and a first-stage impeller ring (13); The first-stage body cover ring (12) is assembled on the pump body (1); The first-stage impeller mouth ring (13) is assembled on the first-stage impeller (8); The first-stage body cover ring (12) and the first-stage impeller ring (13) are structures that can be disassembled and replaced separately.

8. The first-stage double-suction, two-stage radially split centrifugal pump according to claim 1, characterized in that: The secondary friction pair includes: a secondary body cover ring (14) and a secondary impeller ring (15); The secondary body cover ring (14) is assembled on the pump body (1); The secondary impeller mouth ring (15) is assembled on the secondary impeller (9); The secondary body cover ring (14) and the secondary impeller ring (15) are structures that can be disassembled and replaced separately.

9. The first-stage double-suction, two-stage radially split centrifugal pump according to claim 1, characterized in that: The limiting structure includes: a split retaining ring (5) and a fixing sleeve (10); The split retaining ring (5) is mounted on the shaft (11) on the outside of the first stage impeller (8) to restrict the axial movement of the first stage impeller (8); The split retaining ring (5) is provided with a fixing sleeve (10) on its outside, which restricts the split retaining ring (5) from separating; The fixed sleeve (10) is fixed on the shaft (2) to fix and limit the half-clamping ring (5) and at the same time realize the axial positioning function of the first stage impeller (8).

10. The first-stage double-suction, two-stage radially split centrifugal pump according to claim 1, characterized in that: The bearing component (17) adopts a rolling bearing type structure and is equipped with an inner fan, oil ring lubrication and oil mist lubrication to effectively cool the bearing temperature and ensure the service life of the bearing.

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