Air conditioner outdoor unit

Abstract

The invention discloses an outdoor unit of an air conditioner, relates to the technical field of air conditioners, and aims to solve the problem that a two-stage centrifugal compressor in the prior art can cause reduction of power capability of a two-stage impeller. The air conditioner outdoor unit comprises a multi-stage compressor, the multi-stage compressor comprises a first-stage volute, a first-stage impeller, a second-stage compression assembly, a communicating pipe and a rotation eliminating structure, and the first-stage impeller is arranged in the first-stage volute; the first-stage volute and the second-stage compression assembly are communicated through the communicating pipe. The racemization structure comprises a supporting shaft and racemization blades; the plurality of racemization blades are arranged at intervals in the circumferential direction of the supporting shaft, and each racemization blade is provided with a connecting surface connected with the circumferential wall of the supporting shaft; the cross section is located on the connecting face and far away from the supporting shaft. The cross section comprises a datum line, a center line, a first sideline and a second sideline; the datum line is located on the side, close to the first sideline, of the center line and parallel to the axis of the supporting shaft. And the distance between the center line and the datum line is gradually reduced in the flowing direction of the refrigerant. The air conditioner outdoor unit is used for adjusting the temperature of air.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an air conditioning outdoor unit. Background Art

[0002] A two-stage refrigeration centrifugal compressor is usually installed in the outdoor unit of the air conditioner. The two-stage centrifugal compressor usually connects the primary impeller and the secondary impeller through a shaft, and the primary volute outlet and the secondary volute inlet are connected through a bend pipe, so that the refrigerant entering the primary volute is compressed by the primary impeller, and then enters the secondary volute through the bend pipe and is compressed by the secondary impeller, thereby ensuring the efficiency of air conditioning cooling or heating.

[0003] In the related art, in order to ensure the compactness of the structure, when designing a two-stage centrifugal compressor, the first-stage volute is usually offset relative to the first-stage impeller. That is to say, in the axial direction of the first-stage impeller, the center plane of the first-stage impeller perpendicular to its axis does not coincide with the center plane of the first-stage volute perpendicular to the axis of the first-stage impeller.

[0004] The design of the above-mentioned two-stage centrifugal compressor will cause the flow direction of the refrigerant flowing out of the first-stage impeller to change when entering the air flow channel of the first-stage volute, resulting in a vortex phenomenon in the outlet pipe of the first-stage volute when the refrigerant flows out of the first-stage volute and enters the elbow. This will cause the refrigerant to generate resistance to the second-stage impeller after entering the second-stage volute, resulting in a reduction in the working capacity of the second-stage impeller, thereby reducing the energy efficiency of the two-stage centrifugal compressor. Summary of the invention

[0005] An embodiment of the present invention provides an air-conditioning outdoor unit, which solves the problem in the prior art that a two-stage centrifugal compressor may reduce the working capacity of a secondary impeller, thereby reducing the energy efficiency of the two-stage centrifugal compressor.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0007] According to a first aspect of the present application, an air-conditioning outdoor unit is provided, comprising a multi-stage compressor, the multi-stage compressor comprising a primary volute, a primary impeller, a secondary compression assembly, a connecting pipe and a de-rotation structure, wherein the primary impeller is arranged in the primary volute; the secondary compression assembly is spaced apart from the primary volute; the connecting pipe connects the outlet of the primary volute with the secondary compression assembly; the de-rotation structure comprises a support shaft and a plurality of de-rotation blades, the support shaft is connected in the connecting pipe, and the axial direction of the support shaft is consistent with the axial direction of the connecting pipe; the plurality of de-rotation blades are spaced apart along the circumference of the support shaft, and the de-rotation blades have a circumferential wall connected to the support shaft. connecting surface; wherein the de-rotation blade has a cross section located on the side of the connecting surface away from the support shaft, the cross section is parallel to the axis of the support shaft, and perpendicular to the length direction of the de-rotation blade; the cross section includes a reference line, a center line, and a first side line and a second side line arranged along the thickness direction of the de-rotation blade; a straight line perpendicular to a tangent line at any point on the first side line, the midpoint of a line segment formed by the intersection of the first side line and the second side line is located on the center line; the reference line is located on the side of the center line close to the first side line, and is parallel to the axis of the support shaft; along the flow direction of the refrigerant, the distance between the center line and the reference line gradually decreases.

[0008] The air-conditioning outdoor unit provided in the present application has a refrigerant entering a primary volute, and the refrigerant entering the primary volute is compressed once by the rotation of a primary impeller. The outlet of the primary volute is connected to a secondary compression assembly via a connecting pipe, and the refrigerant after being compressed in sequence can flow through the connecting pipe and enter the secondary compression assembly, and the secondary compression assembly compresses the refrigerant for a second time.

[0009] The support shaft of the de-rotation blade is connected to the connecting pipe, and a plurality of de-rotation blades are arranged on the support shaft at intervals along the circumference of the support shaft. And along the flow direction of the refrigerant, the spacing between the center line of the cross section of the de-rotation blade and the reference line is gradually reduced, so that when the refrigerant flows to the de-rotation blade, the refrigerant can quickly and easily contact a side surface of the de-rotation blade in the thickness direction, so that the de-rotation blade can quickly guide the refrigerant. After the refrigerant enters between adjacent de-rotation blades, the restriction of the adjacent de-rotation blades on the refrigerant can reduce the swirl phenomenon of the refrigerant during the flow process, thereby reducing the resistance of the swirl phenomenon of the refrigerant to the secondary compression component, thereby improving the working capacity of the secondary compression component, so as to improve the energy efficiency of the multi-stage compressor.

[0010] In some embodiments, the center line has a first endpoint and a second endpoint arranged in sequence along the flow direction of the refrigerant, and the angle between the tangent of the center line at the first endpoint and the reference line is a first angle; along the direction of the de-rotation blade away from the support shaft, the de-rotation blade has a plurality of cross-sections arranged in sequence, and the first angles of the plurality of cross-sections gradually increase; in this way, the refrigerant can flow toward the inner circumferential wall of the connecting tube close to the de-rotation blade after flowing onto the de-rotation blade, thereby reducing the swirl phenomenon of the part of the refrigerant rotating along the circumference of the connecting tube.

[0011] In some embodiments, when the cross section coincides with the side of the support shaft away from the de-rotation blade, the first angle of the cross section is the edge angle, and the edge angle is greater than or equal to 20° and less than or equal to 50°; when the edge angle is within this range, the streamline of the de-rotation blade along the direction of the de-rotation blade away from the support shaft can be better, thereby improving the de-rotation blade's guide effect on the refrigerant.

[0012] In some embodiments, the edge angle is greater than or equal to 20° and less than or equal to 30°; or, the edge angle is greater than or equal to 30° and less than or equal to 40°; or, the edge angle is greater than or equal to 40° and less than or equal to 50°; the edge angle within the above ranges can make the de-rotation blade have better streamline along the direction of the de-rotation blade away from the support shaft, thereby improving the de-rotation blade's guide effect on the refrigerant.

[0013] In some embodiments, the tangent of the center line at the second endpoint is parallel to the axis of the support shaft; in this way, when the refrigerant flows to the end of the de-swirl blade close to the second endpoint, the flow direction of the refrigerant is close to the axial direction of the connecting tube, thereby further enhancing the de-swirl blade's effect of weakening the refrigerant's swirl phenomenon.

[0014] In some embodiments, the thickness of the de-cycloid blades gradually decreases along the direction of refrigerant flow; this allows the refrigerant to flow through the de-cycloid blades more smoothly when merging, thereby making the refrigerant more streamlined after flowing out of the de-cycloid blades, thereby improving the flow performance of the refrigerant.

[0015] In some embodiments, the difference between the maximum thickness of the de-rotation blade and the minimum thickness of the de-rotation blade is greater than or equal to 2 mm and less than or equal to 4 mm; when the difference between the maximum thickness of the de-rotation blade and the minimum thickness of the de-rotation blade is within the above range, the streamline of the refrigerant after flowing through the de-rotation blade can be ensured, and the resistance of the de-rotation blade to the refrigerant can be reduced.

[0016] In some embodiments, the minimum thickness of the de-rotation blade is greater than or equal to 6 mm and less than or equal to 8 mm; the minimum thickness of the de-rotation blade is within the above range, which can facilitate the processing of the de-rotation blade and also enable the de-rotation blade to have less resistance to the refrigerant.

[0017] In some embodiments, the connecting surface has a first edge line and a second edge line arranged along the thickness direction of the blade, and the first edge line and the second edge line are both straight lines parallel to the axis of the support shaft; and / or, the number of de-rotation blades is greater than or equal to 2 and less than or equal to 5; and / or, the connecting pipe includes an outlet pipe and a guide pipe, the outlet pipe connects the outlet of the first-stage volute and the inlet of the guide pipe, the outlet of the guide pipe is connected to the secondary compression assembly, and the de-rotation structure is arranged in the outlet pipe; the first edge line and the second edge line are both straight lines parallel to the axis of the support shaft, which can make the streamline of the de-rotation blade higher and improve the de-rotation blade's guiding effect on the refrigerant; the number of de-rotation blades is within the above range, so that the de-rotation blade can have a better guiding effect on the refrigerant; the de-rotation structure is arranged in the outlet pipe, which can make the swirl phenomenon of the refrigerant weakened and have a longer buffer, thereby reducing the influence of the refrigerant on the secondary compression assembly.

[0018] According to a second aspect of the present application, an air-conditioning outdoor unit is provided, comprising a multi-stage compressor, the multi-stage compressor comprising a primary volute, a primary impeller, a secondary compression assembly, a connecting pipe and a de-rotation structure, the primary impeller is arranged in the primary volute, and is used to perform a primary compression on the refrigerant entering the primary volute; the secondary compression assembly is spaced apart from the primary volute, and is used to perform a secondary compression on the refrigerant; the connecting pipe connects the outlet of the primary volute with the secondary compression assembly, so that the refrigerant in the primary volute flows through the connecting pipe and enters the secondary compression assembly; the de-rotation structure comprises a support shaft and a plurality of de-rotation blades, the support shaft is connected to the connecting pipe, and the axial direction of the support shaft is consistent with the axial direction of the connecting pipe; the plurality of de-rotation blades are spaced apart along the circumference of the support shaft, and the de-rotation blades have a circumferential connection to the support shaft. The connecting surface of the wall; wherein the derotation blade has a cross section located on the side of the connecting surface away from the support shaft, the cross section is parallel to the axis of the support shaft, and perpendicular to the length direction of the derotation blade; the cross section includes a reference line, a center line, and a first side line and a second side line arranged along the thickness direction of the derotation blade; the connecting surface has a first edge line and a second edge line arranged along the thickness direction of the blade; a straight line perpendicular to the tangent of any point on the first side line, the midpoint of the line segment formed by the intersection of the first side line and the second side line is located on the center line; the reference line is located on the side of the center line close to the first side line, and is parallel to the axis of the support shaft; along the flow direction of the refrigerant, the distance between the center line and the reference line gradually decreases; the first edge line and the second edge line are both straight lines parallel to the axis of the support shaft.

[0019] It should be noted that the technical effects brought about by the implementation method of the second aspect can refer to the technical effects brought about by the corresponding implementation method in the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of a multi-stage compressor in an embodiment of the present application;

[0021] Figure 2 This is one of the partial structural schematic diagrams of the multi-stage compressor in the embodiment of the present application;

[0022] Figure 3 This is the second partial structural diagram of the multi-stage compressor in the embodiment of the present application;

[0023] Figure 4 This is a schematic diagram of the structure of the racemic structure in the embodiment of the present application;

[0024] Figure 5 for Figure 2 A schematic diagram of the structure enlargement in the middle;

[0025] Figure 6 This is one of the partial structural diagrams of the racemic structure in the embodiments of the present application;

[0026] Figure 7 This is the second partial structural diagram of the racemic structure in the embodiment of the present application;

[0027] Figure 8 This is the third partial structural diagram of the racemic structure in the embodiment of the present application;

[0028] Fig. 9 This is the fourth partial structural diagram of the racemic structure in the embodiment of the present application;

[0029] Fig.10 This is one of the structural schematic diagrams of the de-rotation blade in the embodiment of the present application;

[0030] Fig.11 This is the second structural schematic diagram of the de-racemation blade in the embodiment of the present application;

[0031] Fig.12 This is a schematic diagram of the flow field effect of the de-rotation blade when the edge angle is 20° in the embodiment of the present application;

[0032] Fig.13 This is a schematic diagram of the flow field effect of the de-rotation blade when the edge angle is 30° in the embodiment of the present application;

[0033] Fig.14 This is a schematic diagram of the flow field effect of the de-rotation blade when the edge angle is 40° in the embodiment of the present application;

[0034] Fig.15 This is a schematic diagram of the flow field effect of the de-rotation blade when the edge angle is 50° in the embodiment of the present application;

[0035] Fig.16 This is the fifth partial structural diagram of the racemic structure in the embodiment of the present application;

[0036] Fig.17 This is a schematic diagram of the flow field effect when the multi-stage compressor in the embodiment of the present application is not equipped with a de-racing structure;

[0037] Fig.18 This is a schematic diagram of the flow field effect after the multi-stage compressor in the embodiment of the present application is installed with a de-rotation structure.

[0038] Reference numerals:

[0039] 1-first stage volute; 11-first inlet; 12-first outlet;

[0040] 2-First-stage impeller;

[0041] 3-connecting pipe; 31-export pipe; 32-flow guide pipe; 33-support member;

[0042] 4-secondary compression assembly; 41-secondary volute;

[0043] 5-anti-rotation structure; 51-support shaft; 52-anti-rotation blade; 521-inflow part; 522-outflow part; 523-connecting surface; 5231-first area; 5232-second area; 5233-first edge line; 5234-second edge line; 5235-third edge line; 5236-fourth edge line; 524-cross section; 5241-first part; 5242-second part; 5243-baseline; 5244-center line; 52441-first endpoint; 52442-second endpoint; 5245-first side line; 5246-second side line; 5247-third side line; 5248-fourth side line; 525-first side surface; 526-second side surface; 527-third side surface; 528-fourth side surface; 529-first intersection line; 5291-third endpoint; 5292-fourth endpoint. DETAILED DESCRIPTION

[0044] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0045] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the 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 cannot be understood as a limitation on the present invention.

[0046] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, when describing pipelines or channels, the "connected" and "connected" used in this application have the meaning of conduction. The specific meaning needs to be understood in conjunction with the context.

[0048] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0049] As a common household appliance, air conditioners are widely used in daily life. Air conditioners include an outdoor unit and an indoor unit. The indoor air temperature can be regulated through the cooperation between the outdoor unit and the indoor unit.

[0050] Specifically, when the air conditioner is cooling, the compressor in the outdoor unit of the air conditioner compresses the gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant, and the high-temperature and high-pressure gaseous refrigerant passes through the heat exchanger of the outdoor unit of the air conditioner to dissipate heat and become a normal-temperature and high-pressure liquid refrigerant. The normal-temperature and high-pressure liquid refrigerant then enters the indoor unit of the air conditioner, and the normal-temperature and high-pressure liquid refrigerant passes through the heat exchanger of the indoor unit of the air conditioner to absorb a large amount of heat, and the air temperature in the inner cavity of the indoor unit of the air conditioner will decrease. The fan of the indoor unit of the air conditioner then outputs the low-temperature air, thereby cooling the indoor air.

[0051] When the air conditioner is heating, the compressor in the outdoor unit of the air conditioner compresses the gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant. The high-temperature and high-pressure gaseous refrigerant enters the heat exchanger of the indoor unit of the air conditioner to condense and liquefy into a normal-temperature and high-pressure liquid refrigerant, and releases a large amount of heat. The air temperature in the inner cavity of the indoor unit of the air conditioner will rise, and the fan of the indoor unit of the air conditioner will then output the high-temperature air, thereby raising the temperature of the indoor air. The normal-temperature and high-pressure liquid refrigerant is decompressed by the throttling device and enters the heat exchanger of the outdoor unit of the air conditioner. The normal-temperature and high-pressure liquid refrigerant evaporates and absorbs heat to become a low-temperature and low-pressure gaseous refrigerant. The low-temperature and low-pressure gaseous refrigerant enters the compressor in the outdoor unit of the air conditioner to start the next cycle.

[0052] The compressor in the outdoor unit of the air conditioner can be a piston compressor or a centrifugal compressor. A multi-stage compressor is usually used for the centrifugal compressor to enhance the working efficiency of the compressor.

[0053] However, due to the limited space inside the air-conditioning outdoor unit, centrifugal compressors usually adopt a back-to-back structure. Taking a two-stage centrifugal compressor as an example, the first-stage volute and the second-stage volute are arranged at intervals along their axial direction, and then the first-stage volute and the second-stage volute are connected by a curved pipe.

[0054] In the related art, in order to ensure the compactness of the structure of the two-stage centrifugal compressor, when designing the two-stage centrifugal compressor, the first-stage volute is usually offset relative to the first-stage impeller. This will cause the refrigerant in the two-stage centrifugal compressor to change its flow direction when it flows from the first-stage impeller to the first-stage volute, thereby causing the refrigerant to form a swirl at the outlet of the volute, that is, the refrigerant will rotate along the circumference of the pipeline while flowing in the pipeline.

[0055] The swirl of the refrigerant will cause resistance to the secondary impeller after the refrigerant enters the secondary volute, thereby reducing the working capacity of the secondary impeller and reducing the energy efficiency of the two-stage centrifugal compressor.

[0056] Based on this, the present application provides an air conditioner outdoor unit, such as Figure 1 As shown, the air conditioner outdoor unit includes a multi-stage compressor.

[0057] like Figure 1 As shown, the multi-stage compressor comprises a first-stage volute 1 and a first-stage impeller 2. The first-stage volute 1 has a first inlet 11 and a first outlet 12, and the first-stage impeller 2 is arranged in the first-stage volute 1.

[0058] The refrigerant entering the multi-stage compressor can enter the first-stage volute 1 through the first inlet 11 of the first-stage volute 1, and then the first-stage impeller 2 rotates to compress the refrigerant entering the first-stage volute 1.

[0059] The multi-stage compressor further includes a connecting pipe 3 and a secondary compression assembly 4. The secondary compression assembly 4 is spaced apart from the primary volute 1. Specifically, the secondary compression assembly 4 can be arranged on one side of the primary volute 1 along the axial direction of the primary volute 1, or can be arranged on one side of the primary volute 1 along the axial direction perpendicular to the primary volute 1.

[0060] The connecting pipe 3 connects the outlet of the primary volute 1 with the secondary compression assembly 4, that is, the connecting pipe 3 connects the first outlet 12 with the secondary compression assembly 4. The refrigerant compressed once by the primary impeller 2 enters the connecting pipe 3 through the first outlet 12 of the primary volute 1, and enters the secondary compression assembly 4 after flowing through the connecting pipe 3, and the secondary compression assembly 4 performs secondary compression on the refrigerant.

[0061] The number of the two-stage compression assembly 4 can be one or more. When the number of the two-stage compression assembly 4 is more than one, the multiple two-stage compression assemblies 4 are sequentially connected through pipelines. The refrigerant flowing out of the connecting pipe 3 sequentially enters the multiple two-stage compression assemblies 4, and the multiple two-stage compression assemblies 4 sequentially compress the refrigerant, so that the refrigerant is compressed multiple times, so as to improve the compression effect of the multi-stage compressor on the refrigerant.

[0062] The two-stage compression assembly 4 can be a piston compression assembly or a centrifugal compression assembly. Here, the two-stage compression assembly 4 is a centrifugal compression assembly as an example for description.

[0063] Specifically, the two-stage compression assembly 4 includes a two-stage volute 41 and a two-stage impeller (not shown in the figure), and the connecting pipe 3 connects the first outlet 12 of the first-stage volute 1 and the inlet of the second-stage volute 41. The refrigerant compressed by the first-stage impeller 2 flows through the first outlet 12 and the connecting pipe 3 in sequence, and enters the second-stage volute 41 from the inlet of the second-stage volute 41. The refrigerant entering the second-stage volute 41 is subjected to secondary compression through the rotation of the second-stage impeller.

[0064] In order to reduce the influence of the swirl of the refrigerant on the secondary impeller, Figure 2 As shown, the multi-stage compressor further includes a de-swirl structure 5. The de-swirl structure 5 is arranged in the connecting pipe 3 to slow down the swirl phenomenon of the refrigerant.

[0065] Among them, Figure 1 As shown, the connecting pipe 3 includes an outlet pipe 31 and a guide pipe 32. The outlet pipe 31 is the outlet pipe 31 of the primary volute 1, which is arranged at the outlet of the primary volute 1 and connects the outlet of the primary volute 1 and the inlet of the guide pipe 32, so as to allow the refrigerant in the primary volute 1 to flow into the guide pipe 32.

[0066] The outlet of the flow guide pipe 32 is communicated with the secondary compression assembly 4. Specifically, the outlet of the flow guide pipe 32 is communicated with the inlet of the secondary volute 41, so as to transfer the refrigerant in the flow guide pipe 32 to the secondary volute 41.

[0067] The racemization structure 5 can be arranged at multiple positions in the connecting pipe 3. For example, Figure 2 As shown, the racemization structure 5 is disposed in the outlet pipe 31; for example, Figure 3 As shown, the de-racing structure 5 is disposed in the flow guiding pipe 32 .

[0068] Preferably, the de-swirl structure 5 is arranged in the outlet pipe 31. In this way, the swirl phenomenon of the refrigerant can be weakened at the outlet of the first-stage volute 1, and the refrigerant with the weakened swirl phenomenon has a longer buffer time when flowing through the guide pipe 32, thereby effectively reducing the influence of the refrigerant on the second-stage impeller.

[0069] like Figure 4 As shown, the de-rotation structure 5 includes a support shaft 51 and a plurality of de-rotation blades 52. The support shaft 51 is connected to the inside of the connecting pipe 3, and specifically, the support shaft 51 is connected to the inner peripheral wall of the connecting pipe 3.

[0070] For example, Figure 5 As shown, two support members 33 are arranged on the inner circumferential wall of the connecting pipe 3, and the two support members 33 are arranged at intervals along the axial direction of the connecting pipe 3. The support shaft 51 is arranged between the two support members 33, and one end of the support shaft 51 is connected to one of the support members 33, and the other end of the support shaft 51 is connected to the other support member 33, thereby realizing the connection between the support shaft 51 and the circumferential wall of the connecting pipe 3.

[0071] The support member 33 may be a support plate, a support frame, etc. The connection between the support shaft 51 and the support member 33 and the connection between the support member 33 and the connecting pipe 3 may be connected by fasteners such as bolts and screws, or may be connected by casting together.

[0072] Preferably, the support shaft 51 and the support member 33, as well as the support member 33 and the connecting pipe 3 are manufactured by casting together, which saves the subsequent assembly process and reduces the cost.

[0073] like Figure 4 As shown, a plurality of de-rotation blades 52 are arranged on the support shaft 51 at intervals along the circumferential direction of the support shaft 51. Specifically, the de-rotation blades 52 are connected to the peripheral wall of the support shaft 51.

[0074] The de-rotation blade 52 includes an inlet portion 521 and an outlet portion 522 arranged in sequence along the flow direction of the refrigerant. At least a portion of the inlet portion 521 is bent along the thickness direction of the de-rotation blade 52, so that the de-rotation blade 52 can guide the refrigerant flowing therethrough so that the refrigerant can flow along the axial direction of the connecting pipe 3 after flowing out of the de-rotation blade 52.

[0075] The specific bending direction of the inlet portion 521 of the de-rotation blade 52 can be the opposite direction of the circumferential rotation of the refrigerant around the connecting pipe 3. When the refrigerant flows to the de-rotation blade 52 in the connecting pipe 3, it will flow out from the gap between adjacent de-rotation blades 52. In this process, the refrigerant can quickly impact the side surface of the de-rotation blade 52 in the thickness direction in the circumferential direction of the connecting pipe 3.

[0076] In this way, the de-swirl blades 52 can block the refrigerant in the circumferential direction of the connecting pipe 3 and guide the refrigerant to flow out from between two adjacent de-swirl blades 52, thereby reducing the swirl phenomenon of the refrigerant. After the refrigerant flows out of the de-swirl blades 52, it flows along the axial direction of the connecting pipe 3, thereby reducing the resistance of the refrigerant swirl phenomenon to the secondary impeller, thereby improving the working capacity of the secondary impeller and increasing the energy efficiency of the multi-stage compressor.

[0077] Among them, the axial direction of the support shaft 51 is consistent with the axial direction of the connecting pipe 3, so that the refrigerant encounters less resistance from the de-spinning blades 52 when entering the gap between adjacent de-spinning blades 52, which is more conducive to the axial flow of the refrigerant in the connecting pipe 3.

[0078] On this basis, in order to allow the refrigerant to enter between adjacent de-spinning blades 52 more smoothly, so that the de-spinning blades 52 can guide the refrigerant, such as Figure 6 As shown, the side where the de-rotation blade 52 is connected to the peripheral wall of the support shaft 51 is a connection surface 523, and the de-rotation blade 52 also has a cross section 524. The cross section 524 is located on the side of the connection surface 523 away from the support shaft 51, that is, the cross section 524 is any cross section 524 on the side of the connection surface 523 away from the support shaft 51.

[0079] The cross section 524 is parallel to the axis of the support shaft 51 (eg Figure 6 The line M shown in FIG. 1 is perpendicular to the length direction of the de-rotation blade 52 (eg Figure 6 The length direction of the de-spinning blade 52 is the direction in which the de-spinning blade 52 extends in the direction away from the support shaft 51.

[0080] The cross section 524 can be divided into a first portion 5241 and a second portion 5242 arranged in sequence along the flow direction of the refrigerant, wherein the first portion 5241 is located at the inflow portion 521, and the second portion 5242 is located at the outflow portion 522. The connecting surface 523 can be divided into a first area 5231 and a second area 5232 arranged in sequence along the flow direction of the refrigerant, wherein the first area 5231 is located at the inflow portion 521, and the second area 5232 is located at the outflow portion 522.

[0081] like Figure 7 As shown, the cross section 524 includes a reference line 5243, a center line 5244, and a first side line 5245 and a second side line 5246 arranged in sequence along the thickness direction of the de-rotation blade 52, a straight line perpendicular to a tangent line at any point on the first side line 5245, and a midpoint of a line segment formed by the intersection of the first side line 5245 and the second side line 5246 is located on the center line 5244; the reference line 5243 is located on one side of the center line 5244 close to the first side line 5245, and is parallel to the axis of the support shaft 51 (as shown in FIG. Figure 7 Line M) shown in .

[0082] It should be noted that, for any point on the first edge line 5245, the tangent of the first edge line 5245 at that point is the first tangent, the straight line perpendicular to the first tangent is the first perpendicular line, the intersection of the first perpendicular line and the first edge line 5245 is the first intersection, the intersection of the first perpendicular line and the second edge line 5246 is the second intersection, and the line segment formed by the first intersection and the second intersection is the first line segment.

[0083] Since the first sideline 5245 is composed of multiple points, multiple first line segments are formed between the first sideline 5245 and the second sideline 5246 , and the line formed by the midpoints of the multiple first line segments is the centerline 5244 of the cross section 524 .

[0084] Along the flow direction of the refrigerant, the distance between the center line 5244 and the reference line 5243 gradually decreases.

[0085] That is, the center line 5244 may be a curve that bends along the thickness direction of the de-rotation blade 52. In this case, the de-rotation blade 52 is curved, and the bending direction is the direction from the first side line 5245 to the second side line 5246. The center line 5244 may also be an inclined straight line. In this case, the de-rotation blade 52 is an inclined flat plate.

[0086] Here, the center line 5244 is taken as an example of a curve that is curved along the thickness direction of the de-rotation blade 52. The center line 5244 has a first end point 52441 and a second end point 52442 that are sequentially arranged along the flow direction of the refrigerant. Since the distance between the center line 5244 and the reference line 5243 gradually decreases, the portion of the de-rotation blade 52 close to the first end point 52441 is more curved than the portion of the de-rotation blade 52 close to the second end point 52442.

[0087] It should be noted that if Figure 8 As shown, the de-rotation blade 52 has a first side surface 525 in the thickness direction thereof. Fig. 9 As shown, the de-rotation blade 52 also has a second side surface 526 in the thickness direction thereof, and the first side surface 525 and the second side surface 526 are arranged opposite to each other. The first edge line 5245 is located on the first side surface 525, and the second edge line 5246 is located on the second side surface 526.

[0088] Through the above-mentioned arrangement of the de-rotation blade 52, since the portion of the first side surface 525 close to the first end point 52441 has a greater degree of curvature, during the flow of the refrigerant, the refrigerant can more smoothly contact the first side surface 525 (i.e., the side where the first edge line 5245 is located) of the de-rotation blade 52, and under the guidance of the first side surface 525, the refrigerant can smoothly flow out from between adjacent de-rotation blades 52, thereby more effectively guiding the refrigerant.

[0089] In addition, if Figure 8As shown, the de-spinning blade 52 also has a third side 527. Fig. 9 As shown, the de-spinning blade 52 also has a fourth side 528. The third side 527 and the fourth side 528 are arranged in sequence along the flow direction of the refrigerant, and the first side 525, the fourth side 528, the second side 526 and the third side 527 are connected end to end in sequence.

[0090] like Fig.10 As shown, the cross section 524 further includes a third sideline 5247 and a fourth sideline 5248. The third sideline 5247 is located on the third side surface 527, the fourth sideline 5248 is located on the fourth side surface 528, and the first sideline 5245, the fourth sideline 5248, the second sideline 5246 and the third sideline are sequentially connected end to end.

[0091] The third side line 5247 and the fourth side line 5248 are both arcs, which are used to connect the first side line 5245 and the second side line 5246, so that the first side line 5245 smoothly transitions to the second side line 5246. In other words, the third side surface 527 and the fourth side surface 528 are also arcs, which are used to make the first side surface 525 smoothly transition to the second side surface 526.

[0092] In this way, when the refrigerant contacts the de-rotation blade 52 during the flow, it first contacts the third side 527 and then flows to the first side 525. The third side 527 is set to an arc shape, which can reduce the resistance of the de-rotation blade 52 to the refrigerant, so that the refrigerant can smoothly contact the first side 525 and be guided by the first side 525.

[0093] In some embodiments, in order to improve the flow guiding effect of the deswirl blade 52 on the refrigerant and to more effectively reduce the swirl phenomenon of the refrigerant, as shown in FIG. Fig.10 As shown, the angle between the tangent of the center line 5244 at the first end point 52441 and the reference line 5243 is a first angle α; along the direction of the de-rotation blade 52 away from the support shaft 51, the de-rotation blade 52 has a plurality of cross sections 524 arranged in sequence, and the first angle α of the plurality of cross sections 524 gradually increases.

[0094] That is, Figure 8 As shown, the intersection line of the first side 525 and the third side 527 is the first intersection line 529. Along the direction of the de-rotation blade 52 away from the support shaft 51, the first intersection line 529 has a third endpoint 5291 and a fourth endpoint 5292 arranged in sequence. Any point between the third endpoint 5291 and the fourth endpoint 5292 is located on the side of the third endpoint 5291 close to the second side 526, and the fourth endpoint 5292 is also located on the side of the third endpoint 5291 close to the second side 526.

[0095] That is to say, while the de-rotation blade 52 is bent along its thickness direction, the portion of the de-rotation blade 52 close to the third side surface 527 is also in an inclined state.

[0096] In this way, after the refrigerant contacts the first side surface 525 of the de-swirl blade 52, the refrigerant will also flow along the end of the de-swirl blade 52 close to the support shaft 51 toward the end of the de-swirl blade 52 away from the support shaft 51 during the axial flow of the connecting tube 3. In this way, part of the refrigerant can flow toward the inner peripheral wall of the connecting tube 3, thereby causing an impact on part of the refrigerant rotating along the circumferential direction of the connecting tube 3, so as to reduce the swirl phenomenon of part of the refrigerant rotating along the circumferential direction of the connecting tube 3, and further reduce the swirl phenomenon of the refrigerant.

[0097] It should be noted that when the cross section 524 coincides with the side of the de-rotation blade 52 away from the support shaft 51, the first angle α of the cross section 524 is the largest. The first angle α of the cross section 524 can be named as the edge angle β, that is, the largest first angle α is the edge angle β.

[0098] The edge angle β is greater than or equal to 20° and less than or equal to 50°.

[0099] When the edge angle β is within the above range, the streamline of the de-spinning blade 52 is better along the direction in which the de-spinning blade 52 is away from the support shaft 51. The de-spinning blade 52 also has a better guiding effect on the refrigerant, which can make the refrigerant flow more smoothly between adjacent de-spinning blades 52 and can better reduce the swirl phenomenon of the refrigerant.

[0100] And, if Fig.11 As shown, the connection surface 523 has a first edge line 5233 and a second edge line 5234 arranged along the thickness direction of the blade. The connection surface 523 also has a third edge line 5235 and a fourth edge line 5236 arranged in sequence along the flow direction of the refrigerant, and the first edge line 5233, the fourth edge line 5236, the second edge line 5234 and the third edge line 5235 are connected end to end in sequence.

[0101] The first edge line 5233 is located on the first side surface 525 , the second edge line 5234 is located on the second side surface 526 , the third edge line 5235 is located on the third side surface 527 , and the fourth edge line 5236 is located on the fourth side surface 528 .

[0102] At this time, the first edge line 5233 and the second edge line 5234 can be straight lines parallel to the axis of the support shaft 51. That is, the angle between the tangent line of the first edge line 5233 at the intersection of the first edge line 5233 and the third edge line 5235 and the straight line formed by the positive projection of the axis of the support shaft 51 on the connecting surface 523 is 0°. In this way, the de-rotation blade 52 has a better streamline in the direction in which the de-rotation blade 52 is away from the support shaft 51, and the amount of refrigerant flowing to the first side surface 525 of the de-rotation blade 52 is less at the de-rotation blade 52 close to the support shaft 51.

[0103] Furthermore, the above-mentioned arrangement of the de-swirl blade 52 is also beneficial for the refrigerant flowing onto the first side surface 525 of the de-swirl blade 52 to flow toward the end of the de-swirl blade 52 away from the support shaft 51, thereby more effectively eliminating the swirl phenomenon of the refrigerant.

[0104] Exemplarily, the edge angle β is greater than or equal to 20° and less than or equal to 30°. For example, the edge angle β may be 20°, 22°, 25°, 28°, 30°, etc.

[0105] like Fig.12 As shown, when the edge angle β is 20°, the refrigerant has a better streamline when flowing through the de-spinning blade 52, and the refrigerant can maintain linearity as a whole after flowing out of the de-spinning blade 52.

[0106] like Fig.13 As shown, when the edge angle β is 30°, the refrigerant has a better streamline when flowing through the de-spinning blade 52 , and the refrigerant can maintain linearity as a whole after flowing out of the de-spinning blade 52 .

[0107] In addition, compared with the case where the edge angle β is 20°, when the edge angle β is 30°, the streamline height of the refrigerant flow is improved, and the linearity of the refrigerant after flowing out of the de-swirl blade 52 is also improved. It can be seen that when the edge angle β is within the range of greater than or equal to 20° and less than or equal to 30°, the de-swirl blade 52 can reduce the swirl phenomenon of the refrigerant.

[0108] Exemplarily, the edge angle β is greater than or equal to 30° and less than or equal to 40°. For example, the edge angle β may be 30°, 32°, 35°, 38°, 40°, etc.

[0109] like Fig.14As shown, when the edge angle β is 40°, the streamline of the refrigerant flowing through the de-swirl blade 52 is weakened compared to when the edge angle β is 30°, but the overall fluidity of the refrigerant is also good, and the overall linearity of the refrigerant after flowing out of the de-swirl blade 52 is also good. It can be seen that when the edge angle β is within the range of greater than or equal to 30° and less than or equal to 40°, the de-swirl blade 52 can also reduce the swirl phenomenon of the refrigerant.

[0110] Exemplarily, the edge angle β is greater than or equal to 40° and less than or equal to 50°. For example, the edge angle β may be 40°, 42°, 45°, 48°, 50°, etc.

[0111] like Fig.15 As shown, when the edge angle β is 50°, the streamline of the refrigerant flow through the de-swirl blade 52 is weakened compared to when the edge angle β is 40° and the edge angle β is 30°. However, the overall fluidity of the refrigerant and the overall linearity of the refrigerant after flowing out of the de-swirl blade 52 can also reduce the swirl phenomenon of the refrigerant.

[0112] Therefore, when the edge angle β is greater than or equal to 20° and less than or equal to 50°, the de-swirl blade 52 can reduce the swirl phenomenon of the refrigerant. When the edge angle β is about 30°, the de-swirl blade 52 has a better effect of reducing the swirl phenomenon of the refrigerant.

[0113] On this basis, in order to make the refrigerant flow out of the de-spinning blade 52 more linear, as shown in FIG. Fig.10 As shown, the tangent line of the center line 5244 at the second end point 52442 (such as Fig.10 The line N) shown in FIG. 5 is parallel to the axis of the support shaft 51.

[0114] In this way, when the refrigerant flows through the de-swirl blade 52, due to the guiding effect of the de-swirl blade 52, the refrigerant can flow to one end of the de-swirl blade 52 close to the second endpoint 52442. The flow direction of the refrigerant is close to the axial direction of the connecting pipe 3, thereby further enhancing the effect of the de-swirl blade 52 in weakening the swirl phenomenon of the refrigerant.

[0115] In some embodiments, the number of the de-rotation blades 52 is greater than or equal to 2 and less than or equal to 5. When the number of the de-rotation blades 52 is within this range, the de-rotation blades 52 can have a better flow guiding effect on the refrigerant.

[0116] If the number of the de-rotation blades 52 is less than two, the refrigerant cannot be effectively guided; if the number of the de-rotation blades 52 is too large, the resistance of the refrigerant flowing in the connecting pipe 3 will be increased, thereby affecting the fluidity of the refrigerant.

[0117] In some embodiments, in order to make the refrigerant flow through the deswirl blade 52 more smoothly, as shown in FIG. Fig.16 As shown in FIG. 1 , the thickness of the de-rotation blade 52 can be gradually reduced along the direction of the refrigerant flow. That is, the thickness of the de-rotation blade 52 at one end close to the third side surface 527 (eg Fig.16 The thickness H1 shown in FIG. 1 is greater than the thickness of the end of the de-rotation blade 52 near the fourth side 528 (eg Fig.16 Thickness H2 shown in FIG.

[0118] In this way, the refrigerant can flow through the de-cycloid blade 52 and converge more smoothly at the end of the de-cycloid blade 52 close to the fourth side surface 528, thereby making the refrigerant more streamlined after flowing out of the de-cycloid blade 52, thereby improving the flow performance of the refrigerant.

[0119] On this basis, the difference between the maximum thickness of the de-rotation blade 52 and the minimum thickness of the de-rotation blade 52 can be made greater than or equal to 2 mm and less than or equal to 4 mm. That is, the thickness of the end of the de-rotation blade 52 close to the third side surface 527 (such as Fig.16 The thickness H1 shown in FIG. 1 is the same as the thickness of the end of the de-rotation blade 52 near the fourth side 528 (as shown in FIG. Fig.16 The difference between the thickness H2) shown in is greater than or equal to 2 mm and less than or equal to 4 mm.

[0120] For example, the difference between the maximum thickness of the de-rotation blade 52 and the minimum thickness of the de-rotation blade 52 may be 2 mm, 3 mm, 4 mm, and so on.

[0121] When the difference between the maximum thickness of the de-rotation blade 52 and the minimum thickness of the de-rotation blade 52 is within the above range, the streamline of the refrigerant after flowing through the de-rotation blade 52 can be ensured, and the resistance of the de-rotation blade 52 to the refrigerant can be reduced.

[0122] In addition, the minimum thickness of the de-rotation blade 52 is greater than or equal to 6 mm and less than or equal to 8 mm. That is, the thickness of the end of the de-rotation blade 52 close to the fourth side 528 (eg Fig.16 The thickness H2 shown in FIG is greater than or equal to 6 mm and less than or equal to 8 mm.

[0123] For example, the minimum thickness of the de-rotation blade 52 may be 6 mm, 7 mm, 8 mm, etc.

[0124] The minimum thickness of the de-rotation blade 52 is within the above range, which can facilitate the processing of the de-rotation blade 52 and also reduce the resistance of the de-rotation blade 52 to the refrigerant.

[0125] By making the above-mentioned settings on the number and thickness of the de-rotation blades 52, the first angle α of the de-rotation blades 52, the connecting surface 523 and the tangent line 5244 of the midline 5244 of the cross section 524 at the second end point 52442, the overall guiding effect of the de-rotation blades 52 on the refrigerant can be improved.

[0126] like Fig.17 As shown, when the de-swirl structure 5 is not provided in the connecting pipe 3, the refrigerant has an obvious swirl phenomenon when flowing to the outlet of the first-stage volute 1.

[0127] like Fig.18 As shown, after the de-cyclization structure 5 of the present application is set in the connecting pipe 3, the swirl phenomenon of the refrigerant at the outlet of the first-stage volute 1 is significantly weakened, and the refrigerant flows in a straight line as a whole after passing through the de-cyclization structure 5, and there is basically no obvious swirl phenomenon of the refrigerant at the inlet of the second-stage volute 41.

[0128] It can be seen that by arranging the de-swirl structure 5 of the present application in the connecting pipe 3, the swirl phenomenon of the refrigerant can be weakened, thereby reducing the resistance generated by the refrigerant on the secondary impeller after entering the secondary volute 41, and then the working capacity of the secondary impeller can be improved, so as to improve the energy efficiency of the multi-stage compressor.

[0129] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the present application for which protection is claimed, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0130] Although the present application has been described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely exemplary illustrations of the present application as defined by the appended claims, and are deemed to have covered any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

[0131] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An air conditioner outdoor unit, comprising a multi-stage compressor, characterized in that: The multi-stage compressor comprises: First-stage volute; a first-stage impeller, disposed in the first-stage volute; A secondary compression assembly is spaced apart from the primary volute; A connecting pipe connecting the outlet of the first-stage volute with the second-stage compression assembly; A racemic structure, the racemic structure comprising: A support shaft connected to the connecting tube, wherein the axial direction of the support shaft is consistent with the axial direction of the connecting tube; A plurality of de-rotation blades are arranged at intervals along the circumference of the support shaft, and the de-rotation blades have a connection surface connected to the peripheral wall of the support shaft; Wherein, the de-rotation blade has a cross section located on a side of the connection surface away from the support shaft, and the cross section is parallel to the axis of the support shaft and perpendicular to the length direction of the de-rotation blade; The cross section includes a reference line, a center line, and a first sideline and a second sideline arranged along the thickness direction of the de-rotation blade; a straight line perpendicular to a tangent line at any point on the first sideline, and a midpoint of a line segment formed by the intersection of the first sideline and the second sideline is located on the center line; The reference line is located on a side of the center line close to the first side line and is parallel to the axis of the support shaft; along the flow direction of the refrigerant, the distance between the center line and the reference line gradually decreases.

2. The air conditioner outdoor unit according to claim 1, characterized in that: The center line has a first end point and a second end point which are sequentially arranged along the flow direction of the refrigerant, and an angle between a tangent line of the center line at the first end point and the reference line is a first angle; Along the direction in which the de-rotation blade moves away from the supporting shaft, the de-rotation blade has a plurality of cross sections arranged in sequence, and the first angles of the plurality of cross sections gradually increase.

3. The air conditioner outdoor unit according to claim 2, characterized in that: When the cross section coincides with the side of the support shaft away from the de-rotation blade, the first angle of the cross section is an edge angle, and the edge angle is greater than or equal to 20° and less than or equal to 50°.

4. The air conditioner outdoor unit according to claim 3, characterized in that: The edge angle is greater than or equal to 20° and less than or equal to 30°; Or, the edge angle is greater than or equal to 30° and less than or equal to 40°; Or, the edge angle is greater than or equal to 40° and less than or equal to 50°.

5. The air conditioner outdoor unit according to any one of claims 2 to 4, characterized in that: A tangent line of the center line at the second end point is parallel to the axis of the support shaft.

6. The air conditioner outdoor unit according to any one of claims 1 to 4, characterized in that: Along the flow direction of the refrigerant, the thickness of the de-rotation blade gradually decreases.

7. The air conditioner outdoor unit according to claim 6, characterized in that: The difference between the maximum thickness of the de-rotation blade and the minimum thickness of the de-rotation blade is greater than or equal to 2 mm and less than or equal to 4 mm.

8. The air conditioner outdoor unit according to claim 6, characterized in that: The minimum thickness of the de-rotation blade is greater than or equal to 6 mm and less than or equal to 8 mm.

9. The air conditioner outdoor unit according to any one of claims 1 to 4, characterized in that: The number of the de-rotation blades is greater than or equal to 2 and less than or equal to 5; And / or, the connecting pipe includes an outlet pipe and a guide pipe, the outlet pipe connects the outlet of the first-stage volute and the inlet of the guide pipe, the outlet of the guide pipe is connected to the second-stage compression assembly, and the de-racemite structure is arranged in the outlet pipe.

10. An air conditioner outdoor unit, comprising a multi-stage compressor, characterized in that: The multi-stage compressor comprises: First-stage volute; A primary impeller is disposed in the primary volute and is used to compress the refrigerant entering the primary volute; A secondary compression assembly is spaced apart from the primary volute and is used for performing secondary compression on the refrigerant; A connecting pipe connecting the outlet of the first-stage volute with the second-stage compression assembly, so that the refrigerant in the first-stage volute flows through the connecting pipe and enters the second-stage compression assembly; A racemic structure, the racemic structure comprising: A support shaft connected to the connecting tube, wherein the axial direction of the support shaft is consistent with the axial direction of the connecting tube; A plurality of de-rotation blades are arranged at intervals along the circumference of the support shaft, and the de-rotation blades have a connection surface connected to the peripheral wall of the support shaft; Wherein, the de-rotation blade has a cross section located on a side of the connection surface away from the support shaft, and the cross section is parallel to the axis of the support shaft and perpendicular to the length direction of the de-rotation blade; The cross section includes a reference line, a center line, and a first side line and a second side line arranged along the thickness direction of the de-rotation blade; the connecting surface has a first edge line and a second edge line arranged along the thickness direction of the blade; A straight line perpendicular to a tangent line of any point on the first sideline, the midpoint of a line segment formed by the intersection of the first sideline and the second sideline is located on the center line; a reference line is located on the side of the center line close to the first sideline and is parallel to the axis of the support shaft; Along the flow direction of the refrigerant, the distance between the center line and the reference line gradually decreases; the first edge line and the second edge line are both straight lines parallel to the axis of the support shaft.

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