Sealing structure of centrifugal compressor impeller and compressor

Abstract

The invention provides a sealing structure of a centrifugal compressor impeller and a compressor, and relates to the field of refrigerant compression equipment, the sealing structure of the centrifugal compressor impeller comprises a centrifugal impeller and a front end cover, the front end cover is arranged at the inlet end of the centrifugal impeller in the axial direction, and the sealing structure further comprises a first blade fixed to the end, close to the front end cover, of the centrifugal impeller; a first gap exists between the front end cover and the centrifugal impeller, and the first blade is located in the first gap. The first limiting piece is fixed to the front end cover and used for limiting the refrigerant entering the first gap from flowing back to the outlet end of the centrifugal impeller, so that the refrigerant is accumulated in the first gap to form a first sealing layer. The refrigerant is disturbed through the first blades, so that the energy loss and the pressure of the refrigerant are reduced, the centrifugal force is matched with the first limiting piece to form the first sealing layer, and the technical effects that the front end cover and the centrifugal impeller are sealed, and secondary flow is avoided are achieved.

Description

Technical Field

[0001] The present invention relates to the field of refrigerant compression equipment, and particularly to a sealing structure for a centrifugal compressor impeller and a compressor. Background Art

[0002] A centrifugal compressor compresses a refrigerant by means of a high-speed rotating centrifugal impeller. Specifically, the refrigerant enters the centrifugal impeller, and a compression passage with a gradually decreasing width is provided in the centrifugal impeller. The refrigerant is compressed when passing through the compression passage and finally discharged from the outlet of the compression passage, that is, the side surface of the centrifugal impeller.

[0003] When the centrifugal compressor is operating, since the pressure of the refrigerant at the inlet end of the centrifugal impeller is significantly lower than the pressure of the refrigerant at the outlet end, there is an obvious pressure difference between the inlet end and the outlet end of the centrifugal impeller. In order to ensure that the rotation of the centrifugal impeller is not interfered, a gap is usually left between the centrifugal impeller and its front end cover and rear end cover. Therefore, when the centrifugal compressor is operating, there is a problem that the high-pressure refrigerant at the outlet end flows back to the inlet end along the gap between the centrifugal impeller and the front end cover, forming a secondary flow, and the secondary flow will affect the flow of the refrigerant in the impeller and the performance of the refrigerant compressor. Summary of the Invention

[0004] To overcome the problems existing in the related art, the present invention provides a sealing structure for a centrifugal compressor impeller and a compressor.

[0005] To achieve the above object and other related objects, the first aspect of the present invention provides the following technical solution: A sealing structure for a centrifugal compressor impeller, including a centrifugal impeller and a front end cover, the front end cover is disposed at the inlet end of the centrifugal impeller along the axial direction, and further includes:

[0006] A first blade fixed to one end of the centrifugal impeller close to the front end cover, there is a first gap between the front end cover and the centrifugal impeller, and the first blade is located in the first gap; and,

[0007] A first restricting member fixed to the front end cover, the first restricting member is used to restrict the refrigerant entering the first gap from flowing back to the outlet end of the centrifugal impeller, so that the refrigerant accumulates in the first gap to form a first sealing layer.

[0008] In an embodiment of the present invention, a plurality of the first blades are arranged at intervals along the circumferential direction of the centrifugal impeller.

[0009] In an embodiment of the present invention, the first blade is perpendicular to the cross-section of the centrifugal impeller, and the length direction of the first blade is arranged along the radial direction of the centrifugal impeller.

[0010] In an embodiment of the present invention, the first restricting member is arranged in a ring shape. Relative to the first blade, the first restricting member is arranged on the outer side along the radial direction of the centrifugal impeller, and the first restricting member is fixedly sealed with the front end cover.

[0011] In an embodiment of the present invention, a first axial seal is arranged between the centrifugal impeller and the front end cover.

[0012] In an embodiment of the present invention, it further includes a rear end cover. The rear end cover is arranged at one end of the centrifugal impeller away from the front end cover. There is a second gap between the rear end cover and the centrifugal impeller. A second blade is fixed at one end of the centrifugal impeller close to the rear end cover. The second blade is located in the second gap. A second restricting member is arranged on the rear end cover to restrict the refrigerant flowing back to the outlet end of the centrifugal impeller from entering the second gap.

[0013] In an embodiment of the present invention, a plurality of the second blades are arranged at intervals along the circumferential direction of the centrifugal impeller.

[0014] In an embodiment of the present invention, the second restricting member is arranged in a ring shape. Relative to the second blade, the second restricting member is arranged on the outer side along the radial direction of the centrifugal impeller, and the second restricting member is fixedly sealed with the rear end cover.

[0015] In an embodiment of the present invention, a second axial seal is arranged between the centrifugal impeller and the rear end cover.

[0016] The second aspect of the present invention provides the following technical solution: A compressor includes the sealing structure of any one of the centrifugal compressor impellers described above.

[0017] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0018] After the refrigerant is thrown out from the outlet end of the centrifugal impeller, the pressure increases significantly. Due to the pressure difference, part of the refrigerant will enter the first gap from the outlet end of the centrifugal impeller. After entering the first gap, the refrigerant will collide with the first blade. During the collision process, the refrigerant will be disturbed by the first blade to generate turbulence, resulting in its own energy loss and pressure reduction. Thus, under the action of centrifugal force, it is thrown out from the first gap. During the throwing-out process, the movement is blocked by the first restricting member, so that it accumulates in the first gap to form a first sealing layer. The refrigerant in the first sealing layer uses centrifugal force to block the high-pressure refrigerant at the outlet end of the centrifugal impeller from entering, realizing sealing, and preventing the refrigerant at the outlet end of the centrifugal impeller from flowing back to the inlet end.

[0019] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. Description of the Drawings

[0020] The accompanying drawings here are incorporated into and form a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0021] Figure 1 is a cross-sectional view of the sealing structure of the impeller of a centrifugal compressor according to an embodiment of the present invention;

[0022] Figure 2 is a schematic view of the shroud of the sealing structure of the impeller of a centrifugal compressor according to an embodiment of the present invention;

[0023] Figure 3 is a schematic view of another arrangement of the first blade of the sealing structure of the impeller of a centrifugal compressor according to an embodiment of the present invention;

[0024] Figure 4 is a schematic view of another structure of the first restricting member and the second restricting member of the sealing structure of the impeller of a centrifugal compressor according to an embodiment of the present invention.

[0025] Reference numerals:

[0026] 1, centrifugal impeller; 2, front end cover; 3, first blade; 4, first restricting member; 5, shroud; 6, hub; 7, connecting wall; 8, compression channel; 9, assembly hole; 10, liquid inlet; 11, first gap; 12, inlet end; 13, outlet end; 14, first axial seal; 15, first connecting sleeve; 16, section A; 17, section B; 18, rear end cover; 19, second gap; 20, second blade; 21, second restricting member; 22, second axial seal; 23, second connecting sleeve. Detailed Description of the Invention

[0027] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0028] When a centrifugal compressor is in operation, since the pressure of the refrigerant at the inlet end of the centrifugal impeller is significantly lower than the pressure of the refrigerant at the outlet end, there is a significant pressure difference between the inlet end and the outlet end of the centrifugal impeller. In order to ensure that the rotation of the centrifugal impeller is not disturbed, there is usually a gap between the centrifugal impeller and its front end cover and rear end cover. Therefore, when the centrifugal compressor is in operation, there is a problem that the high-pressure refrigerant at the outlet end flows back to the inlet end along the gap between the centrifugal impeller and the front end cover, forming a secondary flow, and the secondary flow will affect the flow of the refrigerant in the impeller and the performance of the refrigerant compressor.

[0029] Based on this, the present disclosure provides a sealing structure for a centrifugal compressor impeller. By rotating the first blade to collide with the refrigerant flowing back into the first gap, the refrigerant generates turbulent energy loss, thereby reducing the pressure of the refrigerant. After the pressure is reduced, the centrifugal force generated by the rotation of the centrifugal impeller is used to fling the refrigerant to move. Then, the movement of the flung refrigerant is restricted by the first restricting member, so that the refrigerant accumulates in the first gap to form a first sealing layer, and the centrifugal force generated by the rotation of the centrifugal impeller is used by this part of the refrigerant to block the high-pressure refrigerant at the outlet end of the centrifugal impeller from entering, achieving sealing, and preventing the refrigerant at the outlet end of the centrifugal impeller from flowing back to the inlet end.

[0030] Please refer to Figure 1 and Figure 2 , an exemplary embodiment of the present disclosure provides a compressor, which includes a sealing structure for a centrifugal compressor impeller. The sealing structure for the centrifugal compressor impeller includes a centrifugal impeller 1, a front end cover 2, a first blade 3, and a first restricting member 4; the centrifugal impeller 1 includes a hub 5 and a disk 6 distributed axially. The hub 5 and the disk 6 are connected by a connecting wall 7. A compression passage 8 is formed between the hub 5, the disk 6, and the connecting wall 7. The inlet end 12 of the compression passage 8 is arranged on the side where the hub 5 is located, and the outlet end 13 is arranged laterally of the centrifugal impeller 1. The width of the compression passage 8 gradually decreases from the inlet end 12 to the outlet end 13. When the centrifugal impeller 1 rotates, the refrigerant enters from the inlet end 12 and is flung out from the outlet end 13, and the pressure increases under compression; an assembly hole 9 is formed in the disk 6 of the centrifugal impeller 1 for connecting a driving source (not shown in the drawings) that drives the centrifugal impeller 1 to rotate. The front end cover 2 is arranged at the axial inlet end 12 of the centrifugal impeller 1, that is, at the end close to the hub 5. A liquid inlet 10 is axially and penetratingly formed in the middle position of the front end cover 2. The refrigerant reaches the inlet end 12 of the compression passage 8 from the liquid inlet 10. The first blade 3 is fixed to one end of the centrifugal impeller 1 close to the front end cover 2, that is, the first blade 3 is fixed on the hub 5 of the centrifugal impeller 1. There is a first gap 11 between the front end cover 2 and the centrifugal impeller 1, and the first blade 3 is located in the first gap 11. The first restricting member 4 is fixed to the front end cover 2. The first restricting member 4 is used to restrict the refrigerant entering the first gap 11 from flowing back to the outlet end 13 of the centrifugal impeller 1, so that the refrigerant accumulates in the first gap 11 to form a first sealing layer. That is, the first restricting member 4 hinders the movement of the refrigerant. It should be noted that the first limiting member does not need to completely block the refrigerant from flowing back from the first gap 11 to the outlet end 13 of the centrifugal impeller 1, as long as the reflux speed is less than the refrigerant inlet speed, so that the refrigerant can accumulate in the first gap 11 to form a first sealing layer. Affected by the centrifugal force generated by the rotation of the centrifugal impeller 1, the refrigerant in the first gap 11 has a tendency to move radially outward along the centrifugal impeller 1. Therefore, the position where the first sealing layer is finally formed in the first gap 11 is near the first restricting member 4.

[0031] In the sealing structure of the centrifugal compressor impeller provided in this embodiment, after the refrigerant is thrown out from the outlet end 13 of the centrifugal impeller 1, the pressure increases significantly. Due to the pressure difference, part of the refrigerant will enter the first gap 11 from the outlet end 13 of the centrifugal impeller 1. After entering the first gap 11, the refrigerant will collide with the first blade 3. During the collision, the refrigerant will be disturbed by the first blade 3 to generate turbulence, resulting in its own energy loss and pressure reduction. Thus, it will be thrown out from the first gap 11 under the action of centrifugal force. During the throwing process, the movement is restricted by the first restricting member 4, so it accumulates in the first gap 11 to form a first sealing layer. The refrigerant in the first sealing layer uses centrifugal force to block the high-pressure refrigerant at the outlet end 13 of the centrifugal impeller 1 from entering, achieving sealing, so that the refrigerant at the outlet end 13 of the centrifugal impeller 1 cannot flow back to the inlet end 12, thereby solving the problem of secondary flow and ensuring the performance of the compressor. At the same time, the first blade 3 is arranged in the first gap 11, and the first gap 11 is the gap that must be left to ensure that the centrifugal impeller 1 can rotate relative to the front end cover 2. Therefore, this solution does not require an additional space to arrange the sealing structure, which can reduce the size of the compressor and make the structure of the compressor more compact.

[0032] Among them, the shape of the first blade 3 is not limited as long as it can collide with the refrigerant entering the first gap 11. For example, the cross-section of the first blade 3 is set as a rectangle, and the length direction of the first blade 3 is arranged along the radial direction of the centrifugal impeller 1; for another example, the cross-section of the first blade 3 is set as an arc; for another example, the cross-section of the first blade 3 is set as a wavy shape.

[0033] Among them, the number and arrangement mode of the first blades 3 are not limited. For example, a plurality of first blades 3 are provided, and several first blades 3 are distributed at intervals around the circumference of the centrifugal impeller 1; for another example, please refer to Figure 3 , a plurality of first blades 3 are provided, and several first blades 3 are distributed in a staggered manner along the circumference of the centrifugal impeller 1.

[0034] Exemplarily, the driving source is set as a magnetic levitation motor. The magnetic levitation motor has the characteristics of high speed and compact structure. While achieving a good pressurization effect on the refrigerant, it can further reduce the size of the compressor. In other embodiments, the driving source can also be replaced by a rotating driving device such as a direct drive motor or a brushless DC motor.

[0035] In one embodiment, the first restricting member 4 is set as a first convex block protruding from the surface of the front end cover 2. The first convex block is arranged to surround the axis of the centrifugal impeller 1 for one week. Relative to the first blade 3, the first convex block is arranged on the radial outer side of the centrifugal impeller 1. The first convex block has a first surface close to the first blade 3, and the first surface is arranged at an angle with one end of the first gap 11 close to the outlet end 13, so that the refrigerant in the first gap 11 collides with the first convex block when being thrown out and its movement is restricted by the influence of the first convex block; or, please refer to Figure 4, the first restricting member 4 is set as the first baffle, the first baffle is arranged to surround the axis of the centrifugal impeller 1 for one week, and the first baffle blocks the opening part of the first gap 11, so as to restrict the refrigerant ejected from the first gap 11.

[0036] Exemplarily, please refer to Figure 2 , a plurality of first blades 3 are arranged at intervals along the circumferential direction of the centrifugal impeller 1, so as to increase the collision frequency between the first blades 3 and the refrigerant entering the first gap 11, improve the energy loss efficiency of the high-pressure refrigerant, and ensure the faster generation of the first sealing layer.

[0037] In an exemplary embodiment, please refer to Figure 1 , the first blade 3 is perpendicular to the cross-section of the centrifugal impeller 1. It should be noted that the cross-section of the centrifugal impeller 1 refers to the section perpendicular to the axis of the centrifugal impeller 1; the length direction of the first blade 3 is arranged along the radial direction of the centrifugal impeller 1. The centrifugal impeller 1 rotates along the circumferential direction. When rotating, the projection of the first blade 3 along the circumferential direction is the effective contact area between the first blade 3 and the refrigerant. Through this arrangement, it can be ensured that the effective contact area of the first blade 3 is the largest, and then the collision area between the first blade 3 and the refrigerant is the largest, ensuring the energy loss efficiency of the refrigerant.

[0038] In an exemplary embodiment, please refer to Figure 1 , the first restricting member 4 is arranged in a ring shape. Relative to the first blade 3, the first restricting member 4 is arranged on the outer side along the radial direction of the centrifugal impeller 1, and the first restricting member 4 is fixedly sealed with the front end cover 2. When the centrifugal impeller 1 rotates, the refrigerant in the first gap 11 will be ejected from the first gap 11 due to the centrifugal force, and will collide with the first restricting member 4 during the ejection process. The first restricting member 4 hinders the refrigerant from being directly ejected from the first gap 11. When the refrigerant in the first gap 11 continues to move towards the direction of the outlet end 13 of the centrifugal impeller 1, it will be hindered by the high-pressure refrigerant at the outlet end 13 of the centrifugal impeller 1, making it difficult for the refrigerant in the first gap 11 to flow out of the first gap 11, and finally causing the refrigerant to accumulate in the first gap 11 to form the first sealing layer.

[0039] Exemplarily, the first restricting member 4 and the front end cover 2 can be but are not limited to being fixedly sealed by means such as gluing, integral molding, welding, etc.

[0040] In an exemplary embodiment, please refer to Figure 1, a first axial seal 14 is provided between the centrifugal impeller 1 and the front end cover 2. A first connecting sleeve 15 is fixed on the shroud 5 of the centrifugal impeller 1. The first connecting sleeve 15 is coaxially arranged with the centrifugal impeller 1. The first connecting sleeve 15 has a radially outer surface, and the first axial seal 14 is arranged between the radially outer surface of the first connecting sleeve 15 and the front end cover 2. During the operation of some refrigerant compressors with high pressure ratios, due to the excessive pressure difference between the outlet end 13 and the inlet end 12 of the centrifugal impeller 1, the centrifugal force of the centrifugal impeller 1 alone is not sufficient to resist the high-pressure refrigerant. That is, part of the refrigerant will continue to move along the first gap 11 under high pressure. At this time, the first axial seal 14 isolates this part of the refrigerant to ensure the sealing performance between the centrifugal impeller 1 and the front end cover 2.

[0041] Wherein, along the axis of the centrifugal impeller 1 and in the direction from the centrifugal impeller 1 towards the front end cover 2, the first connecting sleeve 15 includes an A section 16 and a B section 17 connected to each other. The radius of the A section 16 is greater than that of the B section 17. Different-sized first axial seals 14 are installed on the A section 16 and the B section 17 respectively, so as to further ensure the sealing effect.

[0042] Exemplarily, the first axial seal 14 can but is not limited to adopt axial sealing methods such as mechanical seal, floating ring seal, labyrinth seal, etc.

[0043] In an exemplary embodiment, please refer to Figure 1 , it further includes a rear end cover 18. The rear end cover 18 is arranged at one end of the centrifugal impeller 1 away from the front end cover 2, that is, the rear end cover 18 is arranged at one end close to the disk 6 of the centrifugal impeller 1. There is a second gap 19 between the rear end cover 18 and the centrifugal impeller 1. A second blade 20 is fixed at one end of the centrifugal impeller 1 close to the rear end cover 18, that is, the second blade 20 is fixed on the disk 6 of the centrifugal impeller 1. The second blade 20 is located in the second gap 19. A second restricting member 21 is arranged on the rear end cover 18 to restrict the refrigerant entering the second gap 19 from flowing back to the outlet end 13 of the centrifugal impeller 1. It should be noted that the second limiting member does not need to completely block the refrigerant from flowing back from the second gap 19 to the outlet end 13 of the centrifugal impeller 1. As long as the reflux speed is less than the refrigerant inlet speed and a second sealing layer can be formed by accumulating refrigerant in the second gap 19. Affected by the centrifugal force generated by the rotation of the centrifugal impeller 1, the refrigerant in the second gap 19 has a tendency to move radially outward along the centrifugal impeller 1. Therefore, the position where the second sealing layer is finally formed in the second gap 19 is near the second restricting member 21.

[0044] In this embodiment, the refrigerant is significantly pressurized after being thrown out from the outlet end 13 of the centrifugal impeller 1. Due to the pressure difference, part of the refrigerant enters the second gap 19 from the outlet end 13 of the centrifugal impeller 1. After entering the second gap 19, the refrigerant collides with the second blade 20. During the collision, the refrigerant is disturbed by the second blade 20 to generate turbulence, resulting in its own energy loss and pressure reduction. Thus, it is thrown out of the second gap 19 under the action of centrifugal force. During the throwing-out process, the movement of the refrigerant is restricted by the second restricting member 21, so that it accumulates in the second gap 19 to form a second sealing layer. The refrigerant in the second sealing layer uses centrifugal force to block the high-pressure refrigerant at the outlet end 13 of the centrifugal impeller 1 from entering, achieving sealing, preventing the refrigerant from reaching the position where the drive source is located, and protecting the drive source.

[0045] Among them, the shape of the second blade 20 is not limited, as long as it can collide with the refrigerant entering the second gap 19. For example, the cross-section of the second blade 20 is set as a rectangle, and the length direction of the second blade 20 is arranged along the radial direction of the centrifugal impeller 1; for another example, the cross-section of the second blade 20 is set as an arc; for still another example, the cross-section of the second blade 20 is set as a wavy shape.

[0046] Among them, the number and arrangement mode of the second blades 20 are not limited. For example, multiple second blades 20 are provided, and several second blades 20 are distributed at intervals along the circumferential direction of the centrifugal impeller 1; for another example, multiple second blades 20 are provided, and several second blades 20 are distributed in a staggered manner along the circumferential direction of the centrifugal impeller 1.

[0047] In one embodiment, the second restricting member 21 is set as a second convex block protruding from the surface of the rear end cover 18. The second convex block is arranged to surround the axis of the centrifugal impeller 1 for one week. Relative to the second blade 20, the second convex block is arranged on the radial outer side of the centrifugal impeller 1. The second convex block has a second surface close to the second blade 20, and the second surface is arranged at an angle with one end of the second gap 19 close to the outlet end 13, so that the refrigerant in the second gap 19 collides with the second convex block when being thrown out and its movement is restricted by the second convex block; or, the second restricting member 21 is set as a second baffle, the second baffle is arranged to surround the axis of the centrifugal impeller 1 for one week, and the second baffle blocks the opening part of the second gap 19, thereby restricting the refrigerant thrown out from the second gap 19.

[0048] In an exemplary embodiment, please refer to Figure 1 , a plurality of second blades 20 are arranged at intervals along the circumferential direction of the centrifugal impeller 1. The collision frequency between the second blades 20 and the refrigerant entering the second gap 19 is increased, the energy loss efficiency of the high-pressure refrigerant is improved, and the generation of the second sealing layer is ensured to be faster.

[0049] In an exemplary embodiment, please refer to Figure 1, the second limiting member 21 is arranged in a ring shape and is located outside the second blade 20 along the radial direction of the centrifugal impeller 1. The second limiting member 21 is fixedly sealed with the rear end cover 18. When the centrifugal impeller 1 rotates, the refrigerant in the second gap 19 will be thrown out of the second gap 19 due to centrifugal force and will collide with the second limiting member 21 during the throwing process. The second limiting member 21 hinders the refrigerant from being directly thrown out of the second gap 19. When the refrigerant in the second gap 19 continues to move towards the direction of the outlet end 13 of the centrifugal impeller 1, it will be hindered by the high-pressure refrigerant at the outlet end 13 of the centrifugal impeller 1, making it difficult for the refrigerant in the second gap 19 to flow out of the second gap 19. Eventually, the refrigerant accumulates in the second gap 19 to form a second sealing layer.

[0050] Exemplarily, the second limiting member 21 and the front end cover 2 can be but are not limited to being fixedly sealed by means such as gluing, integral molding, welding, etc.

[0051] In an exemplary embodiment, please refer to Figure 1 , a second axial seal 22 is arranged between the centrifugal impeller 1 and the rear end cover 18. A second connecting sleeve 23 is fixed on the disk 6 of the centrifugal impeller 1. The second connecting sleeve 23 is coaxially arranged with the centrifugal impeller 1. The second connecting sleeve 23 has a radially outer surface. The second axial seal 22 is arranged between the radially outer surface of the second connecting sleeve 23 and the rear end cover 18. During the operation of some refrigerant compressors with a high pressure ratio, due to the excessive pressure difference between the outlet end 13 of the centrifugal impeller 1 and the second gap 19, the centrifugal force of the centrifugal impeller 1 alone is not sufficient to resist the high-pressure refrigerant. That is, part of the refrigerant will continue to move along the second gap 19 under high pressure. At this time, the second axial seal 22 isolates this part of the refrigerant to ensure the sealing performance between the centrifugal impeller 1 and the rear end cover 18.

[0052] Exemplarily, the second axial seal 22 can be but are not limited to adopting axial sealing methods such as mechanical sealing, floating ring sealing, labyrinth sealing, etc.

[0053] In the present invention, the first blade 3 and the second blade 20 respectively collide with the high-pressure refrigerant entering the first gap 11 and the second gap 19, causing the refrigerant to generate turbulent flow to dissipate energy, thereby reducing the pressure. Then, under the action of centrifugal force, the first limiting member 4, and the second limiting member 21, the refrigerant in the first gap 11 forms a first sealing layer, and the refrigerant in the second gap 19 forms a second sealing layer, thereby realizing the sealing of the centrifugal impeller 1 part, preventing the formation of secondary flow, and protecting the driving source part at the same time.

[0054] It should be noted that 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 quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0055] In the present invention, unless otherwise clearly defined and limited, terms such as "installed", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0057] Those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include known common knowledge or conventional technical means in the technical field not disclosed by the present invention. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present invention are pointed out by the claims.

[0058] It should be understood that the present invention is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A sealing structure for a centrifugal compressor impeller, comprising a centrifugal impeller (1) and a front end cover (2), wherein the front end cover (2) is arranged at the axial inlet end (12) of the centrifugal impeller (1), and is characterized in that, Further comprising: A first blade (3) fixed to one end of the centrifugal impeller (1) close to the front end cover (2), there is a first gap (11) between the front end cover (2) and the centrifugal impeller (1), and the first blade (3) is located in the first gap (11); And, A first restricting member (4) fixed to the front end cover (2), the first restricting member (4) is used to restrict the refrigerant entering the first gap (11) from flowing back to the outlet end (13) of the centrifugal impeller (1), so that the refrigerant accumulates in the first gap (11) to form a first sealing layer.

2. The sealing structure of the centrifugal compressor impeller according to claim 1, characterized in that A plurality of the first blades (3) are arranged at intervals along the circumferential direction of the centrifugal impeller (1).

3. The sealing structure of the centrifugal compressor impeller according to claim 1, wherein, The first blade (3) is perpendicular to the cross-section of the centrifugal impeller (1), and the length direction of the first blade (3) is arranged along the radial direction of the centrifugal impeller (1).

4. The sealing structure of the centrifugal compressor impeller according to claim 1, characterized in that, The first restricting member (4) is arranged in a ring shape. Relative to the first blade (3), the first restricting member (4) is arranged on the outer side along the radial direction of the centrifugal impeller (1), and the first restricting member (4) is fixedly sealed with the front end cover (2).

5. The sealing structure of the centrifugal compressor impeller according to claim 1, characterized in that, A first axial seal (14) is provided between the centrifugal impeller (1) and the front end cover (2).

6. The sealing structure of the centrifugal compressor impeller according to any one of claims 1-4, characterized in that, Further comprising a rear end cover (18), the rear end cover (18) is arranged at one end of the centrifugal impeller (1) away from the front end cover (2), there is a second gap (19) between the rear end cover (18) and the centrifugal impeller (1), a second blade (20) is fixed to one end of the centrifugal impeller (1) close to the rear end cover (18), the second blade (20) is located in the second gap (19), and a second restricting member (21) for restricting the refrigerant entering the second gap (19) from flowing back to the outlet end (13) of the centrifugal impeller (1) is arranged on the rear end cover (18).

7. The sealing structure of the centrifugal compressor impeller according to claim 6, characterized in that, A plurality of the second blades (20) are arranged at intervals along the circumferential direction of the centrifugal impeller (1).

8. The sealing structure of the centrifugal compressor impeller according to claim 6, characterized in that, The second restricting member (21) is arranged in a ring shape. Relative to the second blade (20), the second restricting member (21) is arranged on the outer side along the radial direction of the centrifugal impeller (1), and the second restricting member (21) is fixedly sealed with the rear end cover (18).

9. The sealing structure of the centrifugal compressor impeller according to claim 6, wherein, A second axial seal (22) is provided between the centrifugal impeller (1) and the rear end cover (18).

10. A compressor, characterized in that, Comprising the sealing structure of the centrifugal compressor impeller according to any one of claims 1-9.

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