Centrifugal compressor

Abstract

The utility model provides a centrifugal compressor which comprises an impeller, a sealing body and a rotating shaft, the impeller is installed on the rotating shaft and comprises an impeller cover, blades and an impeller back, and the impeller cover and the impeller back are arranged on the two axial sides of the blades respectively; the sealing body comprises a first boss which is arranged on the side, away from the blades, of the impeller cover. The first boss is arranged in the first sealing piece, and the inner wall of the first sealing piece is in clearance fit with the outer wall of the first boss; a plurality of first sealing teeth are arranged on the inner wall of the first sealing piece and are arranged in a step shape in the axial direction of the first sealing piece. According to the utility model, the first boss and the first sealing piece are matched to form stepped sealing, so that the sealing performance of the compressor is improved under a shorter axial sealing size, the gas leakage is reduced, and the working efficiency of the compressor is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of compressors, in particular to a centrifugal compressor. Background Art

[0002] Centrifugal compressors are a vital piece of equipment widely used in industrial production. They are energy-efficient, reliable, and stable, and play a vital role in industries such as chemical engineering, environmental protection, energy, and manufacturing. However, internal fluid leakage is a significant factor affecting centrifugal compressor efficiency during operation. Therefore, a suitable sealing method is crucial for improving compressor efficiency.

[0003] Currently, centrifugal compressors primarily utilize labyrinth seals, mechanical seals, and dry gas seals. Labyrinth seals are the primary sealing method for Freon-based compressors. A labyrinth seal consists of multiple annular sealing teeth arranged sequentially around the rotating shaft, forming a series of trapped gaps and expansion cavities between the teeth. This creates a throttling effect when the sealed medium passes through the gaps, achieving sealing. The smooth labyrinth seal is a common labyrinth seal method used in centrifugal compressors. As the most basic sealing method for compressor interstages and shaft ends, it features a simple structure and is easy to manufacture. However, for two- or multi-stage, high-back-pressure centrifugal compressors, its axial length significantly impacts the compressor rotor dynamics. When the compressor speed is high and the sealing pressure is excessive, the smooth labyrinth seal's axial length must be increased. This results in poor rotor stability, making it impossible to effectively seal with additional sealing teeth, failing to meet sealing requirements. This can lead to significant internal leakage and low efficiency in the compressor. Utility Model Content

[0004] In response to the problems in the prior art, the purpose of the present invention is to provide a centrifugal compressor, the internal sealing body of which has a small axial dimension, which can seal the compressor over a shorter axial dimension, thereby improving the sealing performance of the compressor and reducing compressor leakage.

[0005] The present invention provides a centrifugal compressor comprising an impeller, a sealing body and a rotating shaft, wherein the impeller is mounted on the rotating shaft, the impeller comprises an impeller cover, blades and an impeller back, the impeller cover and the impeller back are respectively arranged on both sides of the axial direction of the blades; the sealing body comprises:

[0006] A first boss is provided on a side of the impeller cover facing away from the blades;

[0007] The first seal member, the first boss is arranged inside the first seal member, and the inner wall of the first seal member is gap-matched with the outer wall of the first boss; a plurality of first sealing teeth are provided on the inner wall of the first seal member, and the first sealing teeth are arranged in a stepped shape along the axial direction of the first seal member.

[0008] In some embodiments, second sealing teeth are provided on the outer wall of the first boss, and the first sealing teeth and the second sealing teeth are staggered in the axial direction.

[0009] In some embodiments, the first sealing tooth includes at least one step, and the outer wall of the first boss is provided with a corresponding number of steps.

[0010] In some embodiments, a first sealing groove is provided between two adjacent first sealing teeth, and the cross section of the first sealing groove is a right-angled trapezoid.

[0011] In some embodiments, the sealing body further includes a second sealing member, which is sleeved outside the rotating shaft, and the inner wall of the second sealing member is gap-fitted with the outer wall of the rotating shaft; a plurality of third sealing teeth are provided on the inner wall of the second sealing member.

[0012] In some embodiments, the third sealing teeth are arranged in a stepped manner along the axial direction of the second sealing member.

[0013] In some embodiments, fourth sealing teeth are provided on the outer wall of the rotating shaft, and the third sealing teeth and the fourth sealing teeth are staggered along the axial direction.

[0014] In some embodiments, a second sealing groove is provided between two adjacent third sealing teeth, and a cross section of the second sealing groove is a right-angled trapezoid.

[0015] In some embodiments, the first sealing teeth and the second sealing teeth are annular and are evenly distributed along the axial direction.

[0016] In some embodiments, the third sealing teeth and the fourth sealing teeth are annular and are evenly distributed along the axial direction.

[0017] The centrifugal compressor provided by the utility model has the following advantages:

[0018] The utility model provides a first sealing member with a stepped arrangement of first sealing teeth. The first sealing member cooperates with the first boss to form a first airtight channel. The gas flowing into the first airtight channel is throttled to reduce its pressure, preventing leakage to the outside, thereby achieving sealing. The stepped first sealing teeth enable sealing at the impeller cover with a shorter axial sealing dimension, thereby improving the sealing performance of the compressor, reducing compressor leakage, and increasing compressor operating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings.

[0020] Figure 1It is a partial cross-sectional view of a centrifugal compressor provided by one embodiment of the present utility model;

[0021] Figure 2 This is a partial perspective view of a centrifugal compressor provided by one embodiment of the present utility model;

[0022] Figure 3 This is a schematic diagram of a first sealing member provided by an embodiment of the present invention, cut along its axial direction;

[0023] Figure 4 This is a schematic diagram of a second sealing member provided by an embodiment of the present invention, cut along its axial direction;

[0024] Figure 5 This is a schematic diagram of the cooperation between the first boss and the first sealing member provided in one embodiment of the present utility model;

[0025] Figure 6 This is a schematic diagram of the cooperation between the rotating shaft and the second sealing member provided in one embodiment of the present utility model.

[0026] Reference numerals:

[0027] 10 wheel covers

[0028] 20 blades

[0029] 30 Wheel Back

[0030] 40 Rotation axis

[0031] 41 Fourth sealing tooth

[0032] 50 First boss

[0033] 51 Second sealing tooth

[0034] 60 First seal

[0035] 61 First sealing tooth

[0036] 62 first sealing groove

[0037] 70 Second seal

[0038] 71 third sealing tooth

[0039] 72 Second sealing groove DETAILED DESCRIPTION

[0040] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. In the figures, identical reference numerals denote identical or similar structures, and thus repetitive descriptions thereof will be omitted. The use of "or" and "either" in this specification may mean "and" or "or."

[0041] In the description of this application, reference to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and integrate different embodiments or examples described in this application, as well as features of different embodiments or examples, unless otherwise contradictory.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include at least one such feature. In the context of this application, "plurality" means two or more, unless otherwise specifically defined.

[0043] In order to solve the problem of poor sealing performance of existing multi-stage centrifugal compressors, an embodiment of the present invention provides a centrifugal compressor and a sealing structure thereof. Figure 1 A partial cross-sectional view of a centrifugal compressor provided by an embodiment of the present utility model is shown; Figure 2 A partial perspective view of a centrifugal compressor provided by an embodiment of the present utility model is shown; Figure 3 A schematic diagram of a first sealing member provided by an embodiment of the present invention, cut along its axial direction, is shown; Figure 4 A schematic diagram of a second sealing member provided by an embodiment of the present invention, cut along its axial direction, is shown; Figure 5 A schematic diagram showing the cooperation between the first boss and the first sealing member provided in one embodiment of the present utility model is shown; Figure 6 A schematic diagram showing the cooperation between the second boss and the second sealing member provided in one embodiment of the utility model is shown.

[0044] like Figures 1 to 6As shown, the centrifugal compressor includes an impeller, a sealing body and a rotating shaft 40. The impeller is mounted on the rotating shaft 40. The impeller includes an impeller cover 10, blades 20, and an impeller back 30. The impeller cover 10 and the impeller back 30 are respectively arranged on both sides of the axial direction of the blades 20. The sealing body includes a first boss 50 and a first sealing member 60. Specifically, the first boss 50 is arranged on the side of the impeller cover 10 away from the blades 20. The first boss 50 is arranged inside the first sealing member 60. The inner wall of the first sealing member 60 is gap-fitted with the outer wall of the first boss 50 to form a first air-sealed channel. A plurality of first sealing teeth 61 are provided on the inner wall of the first sealing member 60. The first sealing teeth 61 are arranged in a stepped manner along the axial direction of the first sealing member 60.

[0045] When the centrifugal compressor is in operation, gas enters the interior of the impeller from the gas inlet end (near the impeller cover 10) and is then compressed into high-pressure gas by the rotating blades 20. The first seal 60 is used to prevent the compressed high-pressure gas from flowing back to the gas inlet end, causing leakage of the compressed gas. When the compressed high-pressure gas flows back to the first air seal channel, the pressure is reduced after throttling and no longer leaks to the outside, thereby achieving sealing. By arranging the first sealing teeth 61 of the first seal 60 in a stepped arrangement, the impeller cover 10 is sealed with a shorter axial sealing dimension, thereby improving the sealing performance of the compressor, reducing leakage of the compressor, and improving the working efficiency of the compressor.

[0046] Further, such as Figure 3 and Figure 5 As shown, a second sealing tooth 51 is provided on the outer wall of the first boss 50, and the first sealing teeth 61 and the second sealing teeth 51 are staggered in the axial direction. The cavity between the second sealing teeth 51 and the first sealing teeth 61 corresponds to each other, which can make the airflow path more tortuous and gradually reduce the airflow pressure.

[0047] Furthermore, the first sealing tooth 61 includes at least one step, and the outer wall of the first boss 50 is provided with a corresponding number of steps. Figure 1 、 Figure 2 and Figure 5 As shown, in this embodiment, the first boss 50 and the first sealing member 60 have only one step. In other embodiments, those skilled in the art can set the specific number and location of the steps on the first boss 50 according to actual needs, and no specific limitation is made here.

[0048] Furthermore, if Figure 2 and Figure 3 As shown, in the embodiment of the present invention, the first sealing teeth 61 and the second sealing teeth 51 are annular and are evenly distributed along the axial direction.

[0049] For further information, please refer to Figure 5A first sealing groove 62 is provided between two adjacent first sealing teeth 61. The cross-section of the first sealing groove 62 is a right-angled trapezoid. In other embodiments, those skilled in the art may configure the cross-sectional shape of the first sealing groove 62 to be rectangular, triangular, or the like according to actual needs, and this is not specifically limited here.

[0050] Please continue reading Figure 1 The sealing body also includes a second sealing member 70, which is sleeved on the outside of the rotating shaft 40; the inner wall of the second sealing member 70 is gap-matched with the outer wall of the rotating shaft 40 to form a second air-sealed channel; a plurality of third sealing teeth 71 are provided on the second sealing member 70.

[0051] The high-pressure airflow compressed by the rotating blades 20 will enter the second air seal channel through the impeller back 30, and the pressure will drop step by step, which can effectively reduce the leakage here and improve the efficiency and performance of the compressor.

[0052] Furthermore, in some embodiments, the third sealing teeth 71 are arranged in a stepped manner along the axial direction of the second sealing member 70. The stepped arrangement of the third sealing teeth 71 enables sealing at the impeller back 30 with a shorter axial sealing dimension, thereby improving the sealing performance of the compressor, reducing leakage in the compressor, and improving the operating efficiency of the compressor.

[0053] Furthermore, fourth sealing teeth 41 are provided on the outer wall of the rotating shaft 40 , and the third sealing teeth 71 and the fourth sealing teeth 41 are staggered in the axial direction.

[0054] Furthermore, if Figure 2 and Figure 4 As shown, the third sealing teeth 71 and the fourth sealing teeth 41 are annular and are evenly distributed along the axial direction.

[0055] Further, such as Figure 6 As shown, a second sealing groove 72 is provided between two adjacent third sealing teeth 71. The cross-section of the second sealing groove 72 is a right-angled trapezoid. In other embodiments, those skilled in the art may set the cross-sectional shape of the first sealing groove 62 to, for example, a rectangle, a triangle, etc., according to actual needs, and no specific limitation is imposed herein.

[0056] In summary, the centrifugal compressor provided by the present invention has the following advantages:

[0057] By providing a stepped arrangement of first sealing teeth on the first sealing member, the first sealing member cooperates with the first boss to form a first airtight channel. The gas flowing into the first airtight channel is throttled, its pressure is reduced, and it no longer leaks to the outside world, thereby achieving sealing. The stepped first sealing teeth enable sealing at the impeller cover with a shorter axial sealing dimension, improving the compressor's sealing performance, reducing compressor leakage, and increasing compressor efficiency.

[0058] The second sealing element and the second boss form a second air-sealing channel. The gas flowing into the second air-sealing channel is throttled to reduce its pressure, thereby achieving sealing. When the third sealing teeth of the second sealing element are arranged in a stepped pattern, sealing can be achieved at the impeller back with a shorter axial sealing dimension, thereby improving the sealing performance of the compressor, reducing compressor leakage, and increasing compressor efficiency.

[0059] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A centrifugal compressor, characterized in that: The impeller comprises an impeller, a sealing body and a rotating shaft, wherein the impeller is mounted on the rotating shaft, the impeller comprises an impeller cover, blades and an impeller back, the impeller cover and the impeller back are respectively arranged on both sides of the axial direction of the blades; the sealing body comprises: A first boss is provided on a side of the impeller cover facing away from the blades; The first seal member, the first boss is arranged inside the first seal member, and the inner wall of the first seal member is gap-matched with the outer wall of the first boss; a plurality of first sealing teeth are provided on the inner wall of the first seal member, and the first sealing teeth are arranged in a stepped shape along the axial direction of the first seal member.

2. The centrifugal compressor according to claim 1, wherein Second sealing teeth are provided on the outer wall of the first boss, and the first sealing teeth and the second sealing teeth are staggered in the axial direction.

3. The centrifugal compressor according to claim 1 or 2, characterized in that: The first sealing tooth includes at least one step, and the outer wall of the first boss is provided with a corresponding number of steps.

4. The centrifugal compressor according to claim 1, wherein: A first sealing groove is provided between two adjacent first sealing teeth, and the cross section of the first sealing groove is a right-angled trapezoid.

5. The centrifugal compressor according to claim 1, characterized in that The sealing body further includes a second sealing member, which is sleeved on the outside of the rotating shaft, and the inner wall of the second sealing member is loosely matched with the outer wall of the rotating shaft; a plurality of third sealing teeth are provided on the inner wall of the second sealing member.

6. The centrifugal compressor according to claim 5, characterized in that The third sealing teeth are arranged in a stepped manner along the axial direction of the second sealing member.

7. The centrifugal compressor according to claim 5 or 6, characterized in that: Fourth sealing teeth are provided on the outer wall of the rotating shaft, and the third sealing teeth and the fourth sealing teeth are staggered along the axial direction.

8. The centrifugal compressor according to claim 7, characterized in that A second sealing groove is provided between two adjacent third sealing teeth, and the cross section of the second sealing groove is a right-angled trapezoid.

9. The centrifugal compressor according to claim 2, characterized in that The first sealing teeth and the second sealing teeth are annular and are evenly distributed along the axial direction.

10. The centrifugal compressor according to claim 7, wherein: The third sealing teeth and the fourth sealing teeth are annular and are evenly distributed along the axial direction.

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