Impeller sealing structure and centrifugal compressor

Abstract

The utility model belongs to the technical field of compressors, and particularly relates to an impeller sealing structure and a centrifugal compressor. A plurality of sealing teeth are arranged on a first contact surface where the impeller is in contact with the sealing body; the second contact face, making contact with the impeller, of the sealing body is made of abradable materials. According to the impeller sealing structure designed by the invention, the sealing teeth with specific structural sizes are processed at the impeller cover of the impeller and are matched with the grindable sealing surface. The grindability of the sealing surface material can greatly reduce the value of the sealing fit clearance S. Due to the fact that the leakage rate at the sealing position is in direct proportion to S, the effect of reducing leakage in the unit and improving the performance of the unit is obvious, cost is low, the structure is simple, and the centrifugal compressor is suitable for being applied to the design of large-diameter, high-pressure, dense-medium and multi-stage impellers and centrifugal compressor units with the high requirement for the performance of the unit.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of compressors, and particularly relates to an impeller sealing structure and a centrifugal compressor. BACKGROUND

[0002] The leakage of the comb seal is proportional to the leakage area A of the seal, A = πDS, wherein D is the sealing diameter and S is the sealing gap between the radii. For a centrifugal compressor with large diameter, high pressure and heavy medium, the single-stage pressure rise of the impeller is large, and the medium leakage from the high-pressure side (the outlet side of the impeller) to the low-pressure side (the inlet side of the impeller) of the seal of the impeller eye ring is large. At present, since the sealing teeth are arranged on the sealing body, the sealing diameter D and the number of sealing teeth are limited by the structural space, so that the optimization space is limited, and at this time, the sealing gap S is particularly important for reducing the leakage in the unit and improving the performance of the unit. At the same time, the ordinary comb seal gap S is too small, and the sealing teeth are easy to be scraped with the impeller during the operation of the unit, so that the sealing fails, and even the vibration problem of the rotor is caused to affect the normal operation of the unit. CONTENT OF THE UTILITY MODEL

[0003] The utility model aims at solving at least one of the technical problems existing in the prior art or related art, i.e., the problem that the medium leakage is large due to the too large sealing gap.

[0004] In view of this, the first aspect of the utility model provides an impeller sealing structure, which sets the sealing teeth on the impeller, cooperates with the abradable sealing surface, and makes the sealing gap extremely small, so that the leakage in the unit is effectively reduced.

[0005] The second aspect of the utility model provides a centrifugal compressor, which uses the above-mentioned impeller sealing structure.

[0006] Specifically, the following technical solutions are included:

[0007] According to the first aspect of the embodiment of the application, an impeller sealing structure is provided, which comprises an impeller and a sealing body; a plurality of sealing teeth are arranged on the first contact surface of the impeller and the sealing body; and the second contact surface of the sealing body and the impeller is made of abradable material.

[0008] Further, the plurality of sealing teeth are arranged side by side and directly machined on the first contact surface.

[0009] Further, the sealing teeth are in the shape of spikes, and the tips thereof extend from the first contact surface to the second contact surface.

[0010] Preferably, the width of one end of the sealing teeth arranged on the first contact surface is 0.1-0.3 mm.

[0011] Further, the impeller comprises a disc, blades and a cover, and the blades are arranged between the disc and the cover; a boss is arranged axially on a side of the cover away from the blades, and an outer surface of the boss is the first contact surface.

[0012] Further, the seal body comprises a seal main body and an abradable seal surface; the abradable seal surface is arranged on the seal main body and between the seal main body and the seal tooth; a side of the abradable seal surface contacting the seal tooth is the second contact surface.

[0013] Preferably, the abradable seal surface comprises an abradable coating arranged on the seal main body.

[0014] Preferably, the abradable seal surface comprises an abradable seal body inlaid on the seal main body.

[0015] Preferably, the seal tooth is made of high-strength stainless steel material; and the abradable material is an aluminum-silicon polyphenyl fat coating.

[0016] According to a second aspect of the embodiments of the present application, a centrifugal compressor is provided, which uses the impeller seal structure according to any of the above technical solutions.

[0017] Compared with the prior art, the centrifugal compressor has at least the following beneficial effects:

[0018] The impeller seal structure designed in the present application is provided with a seal tooth with a specific structure size and an abradable seal surface matched with the seal tooth at the cover of the impeller. The abradable property of the seal surface material can greatly reduce the value of the sealing gap S. Since the leakage at the seal is proportional to S, the structure form can obviously reduce the leakage in the unit, improve the performance of the unit, and has low cost and simple structure, and is suitable for application in the design of centrifugal compressor units with large diameter, high pressure, heavy medium, multi-stage impeller and high performance requirement. BRIEF DESCRIPTION OF DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The detailed description is made with reference to the accompanying drawings.

[0020] Figure 1 FIG. 1 is a cross-sectional view of a seal structure according to an embodiment of the present application;

[0021] Figure 2 FIG. 2 is a cross-sectional view of an impeller structure according to an embodiment of the present application.

[0022] The reference signs are as follows:

[0023] 1 - impeller; 11 - wheel disc; 12 - blade; 13 - wheel cover; 14 - boss;

[0024] 2 - seal body; 21 - seal main body; 22 - abradable seal face;

[0025] 3 - seal tooth;

[0026] 41 - first contact surface; 42 - second contact surface. DETAILED DESCRIPTION

[0027] In order to better understand the above technical solutions, the technical solutions of the embodiments of the present application are described in detail below with the aid of the drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present application and the specific embodiments are detailed descriptions of the technical solutions of the embodiments of the present application, and are not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments of the present application and the specific embodiments can be combined with each other.

[0028] Therefore, according to a first aspect of the embodiments of the present application, a kind of impeller seal structure is provided, including impeller 1 and seal body 2;Multiple seal teeth 3 are provided on the first contact surface 41 of the impeller 1 and the seal body 2 contact;The second contact surface 42 of the seal body 2 and the impeller 1 is set to abradable material.

[0029] Specifically, as shown in Figure 1 , Figure 2 The initial value S0 of the cooperation gap between the top end of the seal tooth 3 and the abradable material on the second contact surface 42 can be designed to be very small or even close to 0 in the structural design. When the impeller 1 rotates with the main shaft, the top end of the seal tooth 3 contacts the abradable material and grinds a small gap value S1, which is the working gap of the seal, and the working gap is generally 50% or less of the ordinary aluminum comb seal. Since the leakage at the seal is proportional to the seal gap S, the impeller seal structure can effectively reduce the internal leakage of the unit. At the same time, the seal tooth 3 is arranged on the impeller 1, so that when the impeller 1 rotates, the seal tooth 3 and the impeller 1 do not scratch and cause seal failure.

[0030] Further, as shown in Figure 1 In an embodiment, multiple seal teeth 3 are arranged side by side, and are directly machined on the first contact surface 41. Specifically, the seal tooth 3 is directly machined on the first contact surface 41 to ensure that the connection between the seal tooth 3 and the impeller 1 is stable enough.

[0031] Further, in an embodiment, as shown in Figure 1As shown, the sealing tooth 3 is spike-shaped, and its tip extends from the first contact surface 41 to the second contact surface 42. Specifically, the sealing tooth 3 can be machined to be narrow and sharp, and its tip can more easily grind a very small wedge-shaped gap on the abrasive material.

[0032] Preferably, in a specific embodiment, the width of one end of the sealing tooth 3 disposed on the first contact surface 41 is 0.1 to 0.3 mm. This width effectively ensures that the sealing tooth 3 can be processed into a spike shape.

[0033] Furthermore, such as Figure 1 As shown, in one embodiment, the impeller 1 includes a disc 11, blades 12, and a cover 13, with the blades 12 disposed between the disc 11 and the cover 13. A boss 14 is axially provided on the side of the cover 13 away from the blades 12, and the outer surface of the boss 14 is the first contact surface 41. Specifically, the boss 14 is a hollow frustum protruding along the axial direction of the impeller 1. The sealing body 2 is sleeved on the outer surface of the boss 14, and the sealing performance between the sealing body 2 and the boss 14 directly affects the leakage of the medium within the unit.

[0034] Furthermore, such as Figure 1 As shown, in one embodiment, the sealing body 2 includes a sealing body 21 and a grindable sealing surface 22; the grindable sealing surface 22 is disposed on the sealing body 21 and located between the sealing body 21 and the sealing tooth 3; the side of the grindable sealing surface 22 that contacts the sealing tooth 3 is the second contact surface 42.

[0035] Preferably, in a specific embodiment, the grindable sealing surface 22 includes a grindable coating disposed on the sealing body 21. Preferably, in a specific embodiment, the grindable sealing surface 22 includes a grindable sealing body embedded in the sealing body 21.

[0036] Preferably, in a specific embodiment, the sealing teeth are made of high-strength stainless steel; the abrasive material is an aluminum-silicon polystyrene coating. Specifically, the hardness of the abrasive material must be lower than the hardness of the sealing teeth 3 to prevent damage and grinding of gaps when the tip of the sealing teeth 3 contacts the abrasive sealing surface 22. Simultaneously, the abrasive material required in this application must possess properties such as low coefficient of friction, strong erosion resistance, stable performance, and ease of adjustment and maintenance, according to specific needs. Therefore, in practical operation, an aluminum-silicon polystyrene coating was chosen. It should be noted that this application is not limited to using an aluminum-silicon polystyrene coating as the abrasive sealing surface 22; other materials that meet the requirements can be used.

[0037] According to a second aspect of the embodiments of the present application, a centrifugal compressor is provided, which uses the impeller sealing structure according to any of the above technical solutions. Therefore, the centrifugal compressor has all the beneficial effects of the above technical solutions, which will not be repeated here.

[0038] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "a specific embodiment", and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0039] The above is only the preferred embodiment of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An impeller seal structure, characterized by, The impeller (1) and the seal body (2) are included. A plurality of seal teeth (3) are arranged on a first contact surface (41) of the impeller (1) in contact with the seal body (2). A second contact surface (42) of the seal body (2) in contact with the impeller (1) is made of an abradable material.

2. The impeller seal structure of claim 1, wherein The plurality of seal teeth (3) are arranged side by side and directly machined on the first contact surface (41).

3. The inducer seal structure of claim 1, wherein The seal teeth (3) are in the shape of spikes, and the tips extend from the first contact surface (41) to the second contact surface (42).

4. The impeller seal construction of claim 1 wherein, The width of one end of the seal teeth (3) arranged on the first contact surface (41) is 0.1-0.3 mm.

5. The impeller seal construction of claim 1 wherein, The impeller (1) includes a disc (11), blades (12) and a cover (13), and the blades (12) are arranged between the disc (11) and the cover (13). A boss (14) is arranged axially on a side of the cover (13) away from the blades (12), and the outer surface of the boss (14) is the first contact surface (41).

6. The inducer seal structure of claim 1, wherein The seal body (2) includes a seal main body (21) and an abradable seal surface (22). The abradable seal surface (22) is arranged on the seal main body (21) and located between the seal main body (21) and the seal teeth (3). The side of the abradable seal surface (22) in contact with the seal teeth (3) is the second contact surface (42).

7. The inducer seal structure of claim 6, wherein The abradable seal surface (22) includes an abradable coating arranged on the seal main body (21).

8. The inducer seal structure of claim 6, wherein The abradable seal surface (22) includes an abradable seal body inlaid on the seal main body (21).

9. The impeller seal structure according to claim 1, wherein The seal teeth (3) are made of high-strength stainless steel. The abradable material is an aluminum-silicon polyphenyl fat coating.

10. A centrifugal compressor characterized by, The centrifugal compressor uses the impeller seal structure according to any one of claims 1-9.

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