Centrifugal compressor with adaptive clearance

Abstract

The present invention relates to a centrifugal compressor with adaptive clearance, which comprises: a rotating part; a fixed part that forms a clearance fit with the rotating part; and a first coating that fills the clearance fit between the rotating part and the fixed part, and the first coating can be worn away when the rotating part rotates, so that a fitting clearance is automatically formed between the rotating part and the fixed part. The present invention sets a first coating that is easy to wear at the clearance fit between the rotating part and the fixed part; during the rotation of the rotating part, the first coating is worn away, so that a fitting clearance is automatically formed between the rotating part and the fixed part. The process is simple and the cost is low. It can not only ensure the clearance required when the machine is running, but also prevent leakage caused by excessive clearance, which is beneficial to the improvement of the energy efficiency of the centrifugal compressor; it can also effectively reduce the accuracy of the parts reprocessing process and the assembly process, and improve the assembly efficiency.

Description

Technical Field

[0001] The invention relates to the field of compressors, and in particular to a centrifugal compressor with adaptive clearance. Background Art

[0002] At present, the internal seal of impeller machinery such as centrifugal compressors generally adopts the comb seal form, that is, a fixed comb seal part cooperates with the rotor gap. When the airflow passes through the gap, it flows through the comb teeth to produce swirl, which is equivalent to throttling. Passing through multiple comb teeth is equivalent to experiencing multiple throttling, and the pressure gradually decreases and tends to back pressure. Therefore, the comb seal structure can avoid leakage caused by pressure difference inside the compressor. Generally speaking, the more comb teeth, the better the sealing effect. However, due to structural limitations, the number of comb teeth is limited.

[0003] Since the comb teeth sealing effect is ensured by the gap, the axial and radial gaps need to be considered simultaneously during manufacturing and assembly, which leads to complex processes and high costs. Summary of the invention

[0004] One of the purposes of the present invention is to provide a centrifugal compressor with adaptive clearance, so as to solve the problem of complex internal sealing process and high cost.

[0005] Some embodiments of the present invention provide a centrifugal compressor, which includes: a rotating part; a fixed part that forms a clearance fit with the rotating part; and a first coating that fills the clearance fit between the rotating part and the fixed part. The first coating can be worn away when the rotating part rotates, so that a fitting gap is automatically formed between the rotating part and the fixed part.

[0006] Optionally, the first coating is provided on the fixing member.

[0007] Optionally, the first coating is provided at a location where the fixed component and the rotating component form a clearance fit.

[0008] Optionally, the thickness of the first coating is 1 mm to 2 mm.

[0009] Optionally, the first coating includes a silicon-aluminum polyphenylene grease coating, a silicon-aluminum graphite coating, a nickel-copper-silicon-graphite coating, a talcum powder coating, a zirconium oxide coating or a nickel diatomaceous earth coating.

[0010] Optionally, the centrifugal compressor includes: a second coating provided on the rotating part.

[0011] Optionally, the second coating is provided at a location where the rotating member and the fixed member form a clearance fit.

[0012] Optionally, the second coating includes a cobalt-coated tungsten carbide coating, a polytetrafluoroethylene coating, a chromium carbide nickel-chromium coating or a ceramic coating.

[0013] Optionally, the wear resistance of the second coating is greater than the wear resistance of the first coating.

[0014] Optionally, the rotating member includes at least one of an impeller and a rotating shaft.

[0015] Optionally, the fixing member includes at least one of a volute, a diffuser and a casing.

[0016] Optionally, the rotating part includes an impeller, and the clearance fit portion between the impeller and the fixed part includes at least one of the clearance fit portion between the impeller and the volute, the clearance fit portion between the impeller and the casing, and the clearance fit portion between the impeller and the diffuser.

[0017] Optionally, the centrifugal compressor includes a single-stage centrifugal compressor or a two-stage centrifugal compressor.

[0018] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0019] In some embodiments, a first coating that is easily worn is provided at the clearance fit between the rotating part and the fixed part; during the rotation of the rotating part, the first coating is worn away so that a fitting clearance is automatically formed between the rotating part and the fixed part. The process is simple and the cost is low. It can not only ensure the clearance required for machine operation, but also prevent leakage caused by excessive clearance, which is beneficial to improving the energy efficiency of the centrifugal compressor. It can also effectively reduce the accuracy of the parts reprocessing process and the assembly process, and improve the assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 A partial schematic diagram of a single-stage compressor provided in some embodiments of the present invention;

[0022] Figure 2 A partial schematic diagram of a two-stage compressor provided in some embodiments of the present invention;

[0023] Figure 3 A schematic diagram of providing a first coating on a fixing member provided in some embodiments of the present invention;

[0024] Figure 4 A schematic diagram of providing a second coating on an impeller according to some embodiments of the present invention;

[0025] Figure 5Schematic diagram of providing a second coating on a rotating shaft according to some embodiments of the present invention.

[0026] Numbers in the attached drawings:

[0027] 1-rotating part; 11-impeller; 111-first-stage impeller; 112-second-stage impeller; 113-wheel cover; 114-wheel hub; 12-rotating shaft;

[0028] 2-fixing member; 21-volute; 22-diffuser; 23-comb seal structure; 24-box;

[0029] 3- first coating;

[0030] 4- Second coating. DETAILED DESCRIPTION

[0031] The technical scheme in the embodiment will be described clearly and completely below in conjunction with the accompanying drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like 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 invention 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 limiting the scope of protection of the present invention.

[0033] like Figure 1 As shown, some embodiments provide a centrifugal compressor comprising a single-stage centrifugal compressor.

[0034] The single-stage centrifugal compressor includes a volute 21 , a diffuser 22 , a casing 24 , an impeller 11 and a rotating shaft 12 .

[0035] The volute 21 is disposed at the end of the housing 24. The diffuser 22 and the rotating shaft 12 are disposed in the housing 24. The impeller 11 is disposed on the rotating shaft 12, and the rotating shaft 12 rotates to drive the impeller 11 to rotate.

[0036] Parts of the impeller 11 form a clearance fit with the volute 21 and the diffuser 22. For example, a clearance fit is formed between the wheel cover of the impeller 11 and the volute 21, and a clearance fit is formed between the wheel hub of the impeller 11 and the diffuser 22.

[0037] A clearance fit is formed between a portion of the rotating shaft 12 and the diffuser 22 .

[0038] like Figure 2 As shown, some embodiments provide a centrifugal compressor including a two-stage centrifugal compressor.

[0039] The two-stage centrifugal compressor includes a volute 21 , a diffuser 22 , a casing 24 , an impeller 11 and a rotating shaft 12 .

[0040] The volute 21 is disposed at the end of the housing 24, and the diffuser 22 and the rotating shaft 12 are disposed in the housing 24. The impeller 11 includes a primary impeller 111 and a secondary impeller 112. The primary impeller 111 and the secondary impeller 112 are both disposed on the rotating shaft 12, and the rotating shaft 12 rotates to drive the primary impeller 111 and the secondary impeller 112 to rotate.

[0041] Part of the first-stage impeller 11 forms a clearance fit with the housing 24 and the diffuser 22. For example, a clearance fit is formed between the wheel cover of the first-stage impeller 11 and the housing 24, and a clearance fit is formed between the wheel hub of the first-stage impeller 11 and the diffuser 22.

[0042] Part of the secondary impeller 112 forms a clearance fit with the casing 24 and the volute 21. For example, a clearance fit is formed between the wheel cover of the secondary impeller 112 and the casing 24, and a clearance fit is formed between the wheel hub of the secondary impeller 112 and the volute 21.

[0043] Part of the rotating shaft 12 forms a clearance fit with the diffuser 22 and the volute 21 .

[0044] Further, a comb-teeth sealing structure 23 may be provided at the matching gap between the first-stage impeller 111 and the housing 24. Preferably, the comb-teeth sealing structure 23 is provided at the housing 24, so that a clearance fit is formed between the comb-teeth sealing structure 23 and the impeller 11.

[0045] Similarly, comb teeth sealing structures 23 can be provided at the matching gap between the first-stage impeller 11 and the diffuser 22, at the matching gap between the second-stage impeller 112 and the casing 24 and the volute 21, and at the matching gap between the rotating shaft 12 and the diffuser 22 and the volute 21 for sealing. Preferably, the comb teeth sealing structure 23 is provided on the fixing member 2.

[0046] Furthermore, the comb-teeth sealing structure 23 is provided on the fixing member 2 , and the comb-teeth sealing structure 23 is also equivalent to the fixing member 2 .

[0047] The impeller 11 and the rotating shaft 12 in the above-mentioned single-stage centrifugal compressor and the double-stage centrifugal compressor are all rotating parts 1. The volute 21, the diffuser 22, the casing 24 and the comb seal structure 23 are all fixed parts 2.

[0048] Furthermore, the diffuser 22 can be processed into one piece with the volute 21 and the returner.

[0049] Furthermore, the comb-teeth sealing structure 23 can be processed into one piece with the volute 21 , the casing 24 , and the diffuser 22 .

[0050] In order to improve the sealing effect of the clearance fit between the rotating part 1 and the fixed part 2 , some embodiments provide a centrifugal compressor, which includes a rotating part 1 , a fixed part 2 that forms a clearance fit with the rotating part 1 , and a first coating 3 .

[0051] The first coating 3 is filled in the gap between the rotating part 1 and the fixed part 2. During the assembly of the centrifugal compressor, due to the presence of the first coating 3, the rotating part 1 is completely in contact with the fixed part 2 at the gap formed between the rotating part 1 and the fixed part 2, or there is a certain pressure. The first coating 3 can be worn away when the rotating part 1 rotates, so that a matching gap is automatically formed between the rotating part 1 and the fixed part 2. Compared with the existing form of setting the comb tooth sealing structure, the sealing process disclosed in the present invention is simple and has low cost.

[0052] Furthermore, the first coating 3 is an easily-worn coating.

[0053] In some embodiments, a first coating 3 that is easy to wear is provided at the clearance fit between the rotating member 1 and the fixed member 2. During the rotation of the rotating member 1, the first coating 3 is worn away, so that a fitting clearance is automatically formed between the rotating member 1 and the fixed member 2. The process is simple and the cost is low. It can not only ensure the clearance required when the machine is running, but also prevent leakage problems caused by excessive clearance, which is beneficial to improving the energy efficiency of the centrifugal compressor; and it can effectively reduce the accuracy of the parts reprocessing process and the assembly process, and improve the assembly efficiency.

[0054] In some embodiments, Figure 3 As shown, the first coating 3 is provided on the fixed part 2. The first coating 3 is an easily-worn coating. The reason why the easily-worn coating is provided on the fixed part 2 instead of the rotating part 1 is that: if the easily-worn coating is provided on the rotating part 1, the easily-worn coating on the surface of the rotating part 1 will be worn away during the rotation process, and the wear amount and wear position of the easily-worn coating are uncertain, which will directly affect the overall dynamic balance of the rotating part 1. Therefore, the first coating 3 is provided on the fixed part 2 as an easily-worn coating.

[0055] In some embodiments, the first coating 3 is disposed at a portion where the fixed component 2 and the rotating component 1 form a clearance fit, and not all portions of the fixed component 2 are provided with the first coating 3 .

[0056] In some embodiments, the thickness of the first coating 3 before being worn is 1 mm to 2 mm. If the thickness of the first coating 3 is too thin, it will be scraped off due to the shear force during rotation. If the thickness of the first coating 3 is too thick, there will be a problem of coating waste and increased cost.

[0057] Furthermore, the first coating 3 is provided by a coating technology or a plating technology.

[0058] Optionally, the abradable coating material used for the first coating 3 comprises a composite material in which a core is coated with a metal or a heat-resistant alloy.

[0059] For example, the first coating layer 3 is formed using nickel-coated graphite material.

[0060] The first coating 3 adds non-metallic material to the metal body to weaken the integrity of the metal and enhance the wear resistance.

[0061] In some embodiments, the first coating 3 includes a silicon-aluminum polyphenylene grease coating, a silicon-aluminum graphite coating, a nickel-copper-silicon-graphite coating, a talcum powder coating, a zirconium oxide coating, or a nickel diatomaceous earth coating.

[0062] The first coating 3 will form a smooth surface after friction, which will not have a negative impact on the airflow. At the same time, the easily-worn material used in the first coating 3 will not be transferred to the rotating part 1 , and will not affect the overall dynamic balance of the rotating part 1 .

[0063] In some embodiments, Figure 4 , Figure 5 As shown, the centrifugal compressor includes a second coating 4, which is provided on the rotating part 1. The second coating 4 is a wear-resistant coating. Hard wear-resistant materials are sprayed on the surface of the rotating part 1 such as the impeller 11 and the rotating shaft 12 to form a wear-resistant coating, thereby improving the wear resistance of the rotating part 1.

[0064] Furthermore, the wear resistance of the second coating 4 is greater than the wear resistance of the first coating 3 .

[0065] In some embodiments, the second coating 4 is disposed at a location where the rotating member 1 and the fixed member 2 form a clearance fit. The spraying location of the second coating 4 on the rotating member 1 is preferably a contact location with the first coating 3 .

[0066] Since the second coating 4 is not easily worn away during the rotation of the rotating part 1, if the second coating 4 is provided on the entire surface of the rotating part 1, it will be difficult to dynamically balance the rotating part 1. Therefore, it is preferred to provide the second coating 4 on the portion of the rotating part 1 that forms a clearance fit with the fixed part 2.

[0067] The second coating 4 is only provided on the portion of the rotating member 1 that contacts the first coating 3 , which can effectively avoid affecting the dynamic balance of the rotating member 1 .

[0068] Since the two materials used in the first coating 3 and the second coating 4 have different wear resistance, when the centrifugal compressor is running, the material with low wear resistance, i.e. the first coating 3, will be worn away, thereby achieving an adaptive gap, effectively avoiding leakage problems caused by excessive reserved gaps, thereby improving the energy efficiency of the centrifugal compressor.

[0069] In some embodiments, the second coating 4 includes a cobalt-coated tungsten carbide coating, a polytetrafluoroethylene coating, a chromium carbide nickel-chromium coating, or a ceramic coating.

[0070] In some embodiments, the thickness of the second coating 4 is in the range of 1 mm to 2 mm.

[0071] In some embodiments, the rotating member 1 includes at least one of an impeller 11 and a rotating shaft 12 .

[0072] In some embodiments, the fixing member 2 includes at least one of a volute 21 , a diffuser 22 , a casing 24 and a comb seal structure 23 .

[0073] In some embodiments, the rotating member 1 includes an impeller 11, and the clearance fit portion between the impeller 11 and the fixed member 2 includes at least one of the clearance fit portion between the wheel cover 113 of the impeller 11 and the volute 21, the clearance fit portion between the wheel cover 113 of the impeller 11 and the casing 24, the clearance fit portion between the hub 114 of the impeller 11 and the diffuser 22, and the clearance fit portion between the radial outlet of the impeller 11 and the volute 21.

[0074] Alternatively, if Figure 3 As shown, the first coating 3 (a layer of easily worn material) is sprayed on the fixed parts 2 such as the volute 21, the comb-teeth sealing structure 23 and the diffuser 22, and the surfaces that are in clearance with the rotating part 1, so that the wheel cover 113 of the impeller 11 and the volute 21, the wheel cover 113 of the impeller 11 and the comb-teeth sealing structure 23, the hub 114 of the impeller 11 and the diffuser 22, and the radial outlet of the impeller 11 and the volute 21 are in contact or have a certain preload. When the rotating shaft 12 drives the impeller 11 to rotate, a part of the easily worn first coating 3 will be worn off, and the required gap will be automatically formed to effectively control the gap between the wheel cover 113 of the impeller 11 and the volute 21, the hub 114 of the impeller 11 and the diffuser 22, etc., thereby eliminating the problem of excessive leakage caused by too large a reserved gap, and reducing the energy efficiency of a small cooling capacity compressor.

[0075] In some embodiments, the clearance fitting parts of the rotating member 1 and the fixed member 2 may be provided with a comb-teeth sealing structure 23. Preferably, the comb-teeth sealing structure 23 is provided on the fixed member 2. Further, a first coating 3 is provided on the comb-teeth sealing structure 23. This avoids the problem of axial and radial clearance fitting accuracy during manufacturing and assembly when sealing is performed only by the comb-teeth sealing structure 23, simplifies the process, and reduces costs.

[0076] In some embodiments, the centrifugal compressor includes a single-stage centrifugal compressor and a two-stage centrifugal compressor.

[0077] The centrifugal compressor adopts the coating structure provided in the above embodiment, which can effectively solve the compressor sealing problem. The use of the easily-worn coating structure can ideally control the gap, prevent excessive leakage of the compressor due to excessive gap, and prevent the problem of reduced compressor energy efficiency.

[0078] In the description of the present invention, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the above components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A centrifugal compressor, It is characterized in that include: A rotating member (1), the rotating member (1) comprising at least one of an impeller (11) and a rotating shaft (12); a fixing member (2) that forms a clearance fit with the rotating member (1), the fixing member (2) comprising at least one of a volute (21), a diffuser (22) and a casing (24); as well as A first coating (3) is filled in the clearance fit between the rotating part (1) and the fixed part (2), and the first coating (3) can be worn away when the rotating part (1) rotates, so that a fitting clearance is automatically formed between the rotating part (1) and the fixed part (2); The clearance fit portion between the impeller (11) and the fixing member (2) comprises at least one of a clearance fit portion between the impeller (11) and the volute (21), a clearance fit portion between the impeller (11) and the casing (24), and a clearance fit portion between the impeller (11) and the diffuser (22); It also includes a second coating (4) disposed on the rotating part (1); the second coating (4) is disposed at a position where the rotating part (1) and the fixed part (2) form a clearance fit; the wear resistance of the second coating (4) is greater than the wear resistance of the first coating (3).

2. The centrifugal compressor according to claim 1, It is characterized in that The first coating (3) is provided on the fixing member (2).

3. The centrifugal compressor according to claim 2, It is characterized in that The first coating (3) is provided at a location where the fixed component (2) and the rotating component (1) form a clearance fit.

4. The centrifugal compressor according to claim 1, It is characterized in that The thickness of the first coating (3) is 1 mm to 2 mm.

5. The centrifugal compressor according to claim 1, It is characterized in that The first coating (3) includes a silicon-aluminum polyphenylene grease coating, a silicon-aluminum graphite coating, a nickel-copper-silicon-graphite coating, a talcum powder coating, a zirconium oxide coating or a nickel diatomaceous earth coating.

6. The centrifugal compressor according to any one of claims 1 to 5, It is characterized in that The second coating (4) includes a cobalt-coated tungsten carbide coating, a polytetrafluoroethylene coating, a chromium carbide nickel-chromium coating or a ceramic coating.

7. The centrifugal compressor according to claim 1, It is characterized in that The centrifugal compressor includes a single-stage centrifugal compressor or a two-stage centrifugal compressor.

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