Symmetrical interlocking seal structure for high-speed centrifugal pump

Abstract

The application belongs to the technical field of centrifugal pump sealing, and discloses a symmetrical interlocking sealing structure for a high-speed centrifugal pump, which comprises: a plurality of static sealing teeth arranged in a ring shape and at intervals on the inner surface of a static sealing ring; a plurality of dynamic sealing teeth arranged in a ring shape and at intervals on the outer surface of a dynamic sealing ring, the dynamic sealing teeth and the static sealing teeth being arranged in a cross manner, and the static sealing teeth and the dynamic sealing teeth surrounding a flow channel between the static sealing ring and the dynamic sealing ring; when the dynamic sealing ring rotates, the dynamic sealing teeth are close to or away from the static sealing teeth, and the flow cross-sectional area of the flow channel correspondingly decreases or increases. The dynamic sealing teeth can be close to or away from the static sealing teeth to form an interlocking chamber, so that the flow cross-sectional area of the flow channel correspondingly decreases or increases. The continuous change of the flow channel cross-sectional area can make the fluid generate strong vortex flow when flowing through the interlocking chamber, dissipate the kinetic energy of the fluid, increase the flow resistance to the axial leakage flow, and significantly reduce the fluid leakage.

Description

Technical Field

[0001] This invention belongs to the field of centrifugal pump sealing technology, and particularly relates to a symmetrical interlocking sealing structure for high-speed centrifugal pumps. Background Technology

[0002] Centrifugal pumps are common rotating machines. As engineering demands for centrifugal pump design conditions continue to increase, centrifugal pumps are developing towards higher speeds and higher heads.

[0003] Annular seals are a commonly used sealing structure inside centrifugal pumps, offering advantages such as simple structure and easy replacement. However, annular seals are currently difficult to adapt to high-speed, high-head operating environments because their throttling characteristics are insufficient, easily leading to leakage of the pumped liquid under such conditions.

[0004] Therefore, how to provide an annular sealing structure with good throttling characteristics is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a symmetrical interlocking sealing structure for high-speed centrifugal pumps to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides a symmetrical interlocking sealing structure for a high-speed centrifugal pump. The sealing structure includes a static sealing ring and a dynamic sealing ring, wherein the dynamic sealing ring is spaced apart and disposed inside the static sealing ring; it also includes:

[0007] Multiple static sealing teeth are arranged in a ring and spaced apart on the inner surface of the static sealing ring;

[0008] Multiple dynamic sealing teeth are arranged in a ring and spaced apart on the outer surface of the dynamic sealing ring. The dynamic sealing teeth are arranged in a cross pattern with the static sealing teeth. The static sealing teeth and dynamic sealing teeth form a flow channel between the static sealing ring and the dynamic sealing ring. When the dynamic sealing ring rotates, the dynamic sealing teeth move closer to or further away from the static sealing teeth, and the flow cross-sectional area of ​​the flow channel decreases or increases accordingly.

[0009] Furthermore, the motion trajectory of the dynamic sealing tooth cross section satisfies the following formula: y=A*sin(n*x), where y is the amplitude of the dynamic sealing tooth moving towards the adjacent static sealing tooth, x is the circumferential arc, A is the maximum amplitude, and n is the number of cycles.

[0010] Furthermore, the dynamic sealing tooth includes:

[0011] Rectangular connecting part;

[0012] The upper sealing tooth gradually tapers from top to bottom and forms an arc surface on both sides. The bottom of the upper sealing tooth is connected to the top of the rectangular connecting part and the shape is adapted.

[0013] The lower sealing tooth gradually tapers from bottom to top and forms an arc surface on both sides. The top of the lower sealing tooth is connected to the bottom of the rectangular connecting part and the shape is adapted.

[0014] Furthermore, the static sealing teeth and the dynamic sealing teeth have the same cross-sectional shape.

[0015] Furthermore, when the dynamic sealing tooth is located on the centerline between two adjacent static sealing teeth, the distance between the dynamic sealing tooth and the static sealing tooth is F, and y is less than F.

[0016] Furthermore, the upper sealing teeth and the lower sealing teeth are arranged symmetrically, the top surface width of the upper sealing teeth is B, the width of the rectangular connecting part is G, and the radius of the arc surface is R, which satisfies the relationship B=G+2R.

[0017] Furthermore, both the dynamic sealing tooth and the static sealing tooth are left-right symmetrical structures; when the dynamic sealing tooth is located on the centerline between two adjacent static sealing teeth, the distance between the central axis of the dynamic sealing tooth and the central axis of the adjacent static sealing tooth is D, which satisfies the relationship F=DGR.

[0018] Furthermore, the radius of the dynamic sealing ring is R. d The length of the dynamic sealing ring is L d The gap between the dynamic sealing ring and the static sealing ring is C, the gap between the top surface of the dynamic sealing tooth and the bottom surface of the static sealing tooth is E, and the height of the rectangular connection part is H.

[0019] Furthermore, A=0.5mm, B=3.2mm, C=2.7mm, D=3.2mm, E=0.9mm, F=0.6mm, G=2mm, H=0.6mm, R=0.6mm, R d =30mm, L d =24mm.

[0020] Furthermore, the dynamic sealing teeth are arranged meanderingly on the outer surface of the dynamic sealing ring.

[0021] The present invention discloses the following technical effects:

[0022] In this invention, the dynamic sealing ring is not a circular ring, but rather meanders along the outer surface of the dynamic sealing ring (non-axial with the static sealing ring). Therefore, when the dynamic sealing ring rotates, the dynamic sealing teeth can move closer to or further away from the static sealing teeth to form an interlocking chamber, causing the flow cross-sectional area of ​​the flow channel to correspondingly decrease or increase. The continuous change in the flow channel cross-sectional area can generate strong eddies when the fluid flows through the interlocking chamber, dissipating the fluid's kinetic energy, increasing the flow resistance to axial leakage, and significantly reducing fluid leakage. Furthermore, since the dynamic sealing teeth are not circular, they can generate a periodic squeezing and expansion effect on the fluid during the rotation of the dynamic sealing ring, further increasing the fluid flow resistance and reducing fluid leakage. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a schematic diagram showing the fit between the static sealing ring and the dynamic sealing ring;

[0026] Figure 3 This is a schematic diagram of the dynamic sealing tooth structure;

[0027] Figure 4 A diagram showing the trajectory of one revolution of the dynamic sealing tooth;

[0028] Figure 5 A schematic diagram showing the leakage and error under different inlet and outlet pressure differences and rotational speeds;

[0029] Figure 6 The internal flow characteristics are shown when the dynamic seal tooth rotates 90°.

[0030] Figure 7 The internal flow characteristic diagram is shown when the dynamic seal tooth is rotated 180° (the internal flow characteristic diagrams are the same when rotated 0° and 180°).

[0031] Figure 8 The internal flow characteristics are shown when the dynamic seal tooth rotates 270°.

[0032] Among them, 1. Static sealing ring; 2. Dynamic sealing ring; 3. Static sealing teeth; 4. Dynamic sealing teeth; 401. Rectangular connecting part; 402. Upper sealing teeth; 403. Lower sealing teeth; 5. Pump body. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] like Figures 1-8 As shown in the figure, an embodiment of the present invention discloses a symmetrical interlocking sealing structure for a high-speed centrifugal pump. The sealing structure includes a static sealing ring 1 and a dynamic sealing ring 2, which are disposed in the pump body 5 of the high-speed centrifugal pump. The specific arrangement is prior art and will not be described in detail here. The dynamic sealing ring 2 is spaced apart and disposed inside the static sealing ring 1. The invention also includes:

[0036] Multiple static sealing teeth 3 are arranged in a ring and spaced apart on the inner surface of the static sealing ring 1;

[0037] Multiple dynamic sealing teeth 4 are arranged in a ring and spaced apart on the outer surface of the dynamic sealing ring 2. The dynamic sealing teeth 4 and the static sealing teeth 3 are arranged in a cross pattern. The static sealing teeth 3 and the dynamic sealing teeth 4 form a flow channel between the static sealing ring 1 and the dynamic sealing ring 2. When the dynamic sealing ring 2 rotates, the dynamic sealing teeth 4 move closer to or further away from the static sealing teeth 3, and the flow cross-sectional area of ​​the flow channel decreases or increases accordingly.

[0038] In this embodiment, the motion trajectory of the dynamic sealing tooth 4 cross section satisfies the following formula: y=A*sin(n*x), where y is the amplitude of the movement of the dynamic sealing tooth 4 towards the adjacent static sealing tooth 3, x is the circumferential arc, A is the maximum amplitude, and n is the number of cycles.

[0039] In this embodiment, the dynamic sealing tooth 4 includes:

[0040] Rectangular connecting part 401;

[0041] The upper sealing tooth 402 gradually tapers from top to bottom and forms an arc surface (1 / 4 arc) on both sides. The bottom of the upper sealing tooth 402 is connected to the top of the rectangular connecting part 401 and the shape is adapted.

[0042] The lower sealing tooth 403 gradually tapers from bottom to top and forms an arc surface on both sides. The top of the lower sealing tooth 403 is connected to the bottom of the rectangular connecting part 401 and the shape is adapted.

[0043] In this embodiment, the static sealing tooth 3 and the dynamic sealing tooth 4 have the same cross-sectional shape.

[0044] In this embodiment, when the dynamic sealing tooth 4 is located at the centerline between two adjacent static sealing teeth 3, the distance between the dynamic sealing tooth 4 and the static sealing tooth 3 is F, and y is less than F.

[0045] In this embodiment, the upper sealing tooth 402 and the lower sealing tooth 403 are arranged symmetrically. The top surface width of the upper sealing tooth 402 is B, the height of the rectangular connecting part 401 is H, the width is G, and the radius of the arc surface is R, which satisfies the relationship B=G+2R.

[0046] In this embodiment, both the dynamic sealing tooth 4 and the static sealing tooth 3 are left-right symmetrical structures; when the dynamic sealing tooth 4 is located on the centerline between two adjacent static sealing teeth 3, the distance between the central axis of the dynamic sealing tooth 4 and the central axis of the adjacent static sealing tooth 3 is D, which satisfies the relationship F=DGR.

[0047] In this embodiment, the gap between the dynamic sealing ring 2 and the static sealing ring 1 is C.

[0048] In this embodiment, the gap between the top surface of the dynamic sealing tooth 4 and the bottom surface of the static sealing tooth 3 is E.

[0049] In this embodiment, the radius of the dynamic sealing ring 2 is R. d The length of the dynamic sealing ring 2 is L. d .

[0050] The design parameters for this embodiment are shown in the table below:

[0051] Design parameters A(mm) B(mm) C(mm) D(mm) E(mm) F(mm) G(mm) numerical values 0.5 3.2 2.7 3.2 0.9 0.6 2 Design parameters H(mm) R(mm) <![CDATA[R d (mm)]]> <![CDATA[L d (mm)]]> numerical values 0.6 0.6 30 24

[0052] The fluid flow process is as follows:

[0053] When pressurized fluid passes through the sealing gap (interlocking chamber) formed by the dynamic sealing tooth 4 and the static sealing tooth 3, it generates strong vortices, dissipating the fluid's kinetic energy and increasing the flow resistance to axial leakage. Each time the fluid flows through an interlocking chamber, its energy is dissipated in the same way; after multiple energy dissipations, the fluid's energy is significantly reduced, thus substantially decreasing the leakage rate. Furthermore, due to the circumferential non-uniformity of the dynamic sealing tooth 4, the interlocking chamber can periodically shrink and expand during rotation, further compressing and expanding the internal fluid, increasing flow resistance and effectively suppressing circumferential flow and fluid leakage.

[0054] Using the surface formed by rotating the centerline between two adjacent static sealing teeth 3 as a reference surface, the circumferential motion trajectory line of the dynamic sealing tooth 4 is as follows: Figure 3 As shown.

[0055] CFD software was used to calculate the sealing structure of this embodiment (interlocking sinusoidal sealing teeth) and the traditional high-speed centrifugal pump under the same geometric dimensions. The traditional high-speed centrifugal pump sealing structure uses interlocking equidistant sealing teeth, traditional staggered sealing teeth, a single static sealing tooth, and a single dynamic sealing tooth, respectively. Leakage was collected under different inlet and outlet pressure differences and speeds, and the sealing performance was compared and analyzed. The results are as follows:

[0056] like Figure 5 As shown, with the increase of differential pressure, the leakage of different sealing structures shows an approximately linear relationship with the differential pressure, and the leakage of a single dynamic / static sealing tooth 3 is more sensitive to differential pressure.

[0057] Compared to traditional high-speed centrifugal pump sealing structures, this embodiment exhibits lower leakage, meaning that the interlocking sinusoidal sealing teeth used in this embodiment effectively reduce leakage. Furthermore, the leakage of this embodiment remains lower than that of traditional high-speed centrifugal pump sealing structures under various pressure differential conditions. Compared to this embodiment, the relative errors of other structures are not sensitive to changes in pressure differential; the errors of the interlocking equidistant sealing teeth, traditional staggered sealing teeth, single static sealing tooth 3, and single dynamic sealing tooth 4 relative to this embodiment are approximately 22%, 69%, 373%, and 392%, respectively.

[0058] like Figures 6-8 As shown, when the fluid flows through the interlocked chamber formed by the dynamic sealing tooth 4 and the static sealing tooth 3, the pressurized fluid generates a strong vortex as it flows through the interlocked chamber. This vortex is approximately proportional to the size of the interlocked chamber. During the rotation of the dynamic sealing tooth 4, the interlocked chamber undergoes periodic shrinking and expansion, resulting in periodic compression and expansion of the fluid inside. The vortex continuously changes, thereby continuously dissipating the fluid's kinetic energy and increasing the flow resistance to axial leakage. Therefore, it can be concluded that this embodiment exhibits superior sealing performance under the same operating conditions, achieving the goal of low leakage.

[0059] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to 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 of this invention.

[0060] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A symmetrical interlocking sealing structure for a high-speed centrifugal pump, the sealing structure comprising a static sealing ring (1) and a dynamic sealing ring (2), wherein the dynamic sealing ring (2) is spaced apart and disposed inside the static sealing ring (1); characterized in that, Also includes: Multiple static sealing teeth (3) are arranged in a ring and spaced apart on the inner surface of the static sealing ring (1); Multiple dynamic sealing teeth (4) are arranged in a ring and spaced apart on the outer surface of the dynamic sealing ring (2). The dynamic sealing teeth (4) are arranged crosswise with the static sealing teeth (3). The static sealing teeth (3) and the dynamic sealing teeth (4) form a flow channel between the static sealing ring (1) and the dynamic sealing ring (2). When the dynamic sealing ring (2) rotates, the dynamic sealing teeth (4) move closer to or further away from the static sealing teeth (3), and the flow cross-sectional area of ​​the flow channel decreases or increases accordingly. The motion trajectory of the cross section of the dynamic sealing tooth (4) satisfies the following formula: y=A*sin(n*x), where y is the amplitude of the movement of the dynamic sealing tooth (4) towards the adjacent static sealing tooth (3), x is the circumferential arc, A is the maximum amplitude, and n is the number of cycles; The dynamic sealing tooth (4) includes: Rectangular connecting part (401); The upper sealing tooth (402) gradually tapers from top to bottom and forms an arc surface on both sides. The bottom of the upper sealing tooth (402) is connected to the top of the rectangular connecting part (401) and the shape is adapted. The lower sealing tooth (403) gradually tapers from bottom to top and forms an arc surface on both sides. The top of the lower sealing tooth (403) is connected to the bottom of the rectangular connecting part (401) and the shape is adapted. The static sealing tooth (3) and the dynamic sealing tooth (4) have the same cross-sectional shape.

2. The symmetrical interlocking sealing structure for a high-speed centrifugal pump according to claim 1, characterized in that, When the dynamic sealing tooth (4) is located at the centerline between two adjacent static sealing teeth (3), the distance between the dynamic sealing tooth (4) and the static sealing tooth (3) is F, and y is less than F.

3. The symmetrical interlocking sealing structure for a high-speed centrifugal pump according to claim 2, characterized in that, The upper sealing tooth (402) and the lower sealing tooth (403) are arranged symmetrically. The top surface width of the upper sealing tooth (402) is B, the width of the rectangular connecting part (401) is G, and the radius of the arc surface is R, which satisfies the relationship B=G+2R.

4. The symmetrical interlocking sealing structure for a high-speed centrifugal pump according to claim 3, characterized in that, Both the dynamic sealing tooth (4) and the static sealing tooth (3) are left-right symmetrical structures. When the dynamic sealing tooth (4) is located on the centerline between two adjacent static sealing teeth (3), the distance between the central axis of the dynamic sealing tooth (4) and the central axis of the adjacent static sealing tooth (3) is D, which satisfies the relation F=DGR.

5. The symmetrical interlocking sealing structure for a high-speed centrifugal pump according to claim 4, characterized in that, The radius of the dynamic sealing ring (2) is R. d The length of the dynamic sealing ring (2) is L. d The gap between the dynamic sealing ring (2) and the static sealing ring (1) is C, the gap between the top surface of the dynamic sealing tooth (4) and the bottom surface of the static sealing tooth (3) is E, and the height of the rectangular connecting part (401) is H.

6. The symmetrical interlocking sealing structure for a high-speed centrifugal pump according to claim 5, characterized in that, A=0.5mm,B=3.2mm,C=2.7mm,D=3.2mm,E=0.9mm,F=0.6mm,G=2mm,H=0.6mm,R=0.6mm,R d =30mm,L d =24mm。 7. A symmetrical interlocking sealing structure for a high-speed centrifugal pump according to any one of claims 1-6, characterized in that, The dynamic sealing teeth (4) are arranged in a meandering manner on the outer surface of the dynamic sealing ring (2).

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