Impeller and compressor

Abstract

An impeller (10) and a compressor (100). The impeller (10) comprises an impeller disk (11), an impeller shroud (12) and a plurality of blades (13); the blades (13) are connected to the impeller disk (11) and the impeller shroud (12); the impeller disk (11), the impeller shroud (12) and two adjacent blades (13) enclose to form an airflow channel (14); the airflow channel (14) is provided with a first inlet (141); the impeller shroud (12) is provided with a plurality of through holes (1221); and the through holes (1221) communicate with the airflow channel (14) and the first inlet (141). The impeller (10) can prevent the occurrence of blockage or surge, thereby avoiding damage.

Description

Impeller and compressor

[0001] Priority information

[0002] This application claims priority and benefit to patent application No. 202510186093.X, filed with the China National Intellectual Property Administration on February 19, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of compressor technology, and more specifically, to an impeller and a compressor. Background Technology

[0004] Centrifugal compressors are widely used in the refrigeration industry. However, centrifugal compressors can become clogged when the actual flow rate is greater than the design flow rate, and can stall when the actual flow rate is less than the design flow rate. If the flow rate is further reduced and exceeds the stall limit, the centrifugal compressor will become more unstable and surge, which can lead to impeller damage and even damage to the compressor and connected equipment. Summary of the Invention

[0005] This application provides an impeller and a compressor to solve at least one of the above-mentioned technical problems.

[0006] The impeller of this application embodiment is used in a compressor and includes a disc, a cover and multiple blades. The blades connect the disc and the cover. The disc, the cover and two adjacent blades enclose an airflow channel. The airflow channel has a first inlet. The cover has multiple through holes that connect the airflow channel and the first inlet.

[0007] The impeller provided in this application has a through hole in the impeller cover so that the first inlet can communicate with the airflow channel. When the actual flow rate of the centrifugal compressor is too high or too low, the through hole can balance the air pressure inside the airflow channel and at the first inlet, thereby avoiding blockage or surge and preventing damage to the compressor and connected equipment.

[0008] In some embodiments, the wheel cover includes a cover body opposite to the wheel disc and an air intake cylinder extending from the cover body in a direction away from the wheel disc, the first inlet being formed in the air intake cylinder, the air intake cylinder including an end face facing away from the cover body, and the through hole being formed on the end face.

[0009] Thus, the through hole is set on the end face, which facilitates the machining of the through hole.

[0010] In some embodiments, the through hole is a straight hole extending along the length of the air inlet cylinder.

[0011] Thus, the through hole is set along the length of the air inlet cylinder, which facilitates the machining of the through hole.

[0012] In some embodiments, the diameter of the through hole is 50% to 70% of the thickness of the air inlet cylinder.

[0013] In this way, the through hole ensures the structural strength of the impeller while maintaining the function of balancing the air pressure inside the airflow channel and at the first inlet.

[0014] In some embodiments, the compressor further includes a housing and an adjusting housing, both of which are disposed within the housing. The adjusting housing is a hollow cylindrical shape and includes a second outlet corresponding to the first inlet. The adjusting housing also includes guide vanes configured to be movably mounted inside the adjusting housing to control the opening degree of the adjusting housing.

[0015] In this way, by controlling the opening of the housing through the guide vanes, the pressure at the first inlet can be adjusted, thereby helping to balance the air pressure inside the airflow channel and at the first inlet.

[0016] In some embodiments, the guide vane is rotatably mounted inside the adjustment housing.

[0017] In this way, the guide vane can control the opening of the regulating housing while also changing the airflow direction to adjust the pressure on the side of the through hole near the first inlet, thereby controlling the airflow velocity between the airflow channel and the first inlet and improving the efficiency of balancing the air pressure inside the airflow channel and at the first inlet.

[0018] In some embodiments, the guide vane is fan-shaped, and the distance between the second outlet and the impeller in the direction of the impeller's axis of rotation is less than 1.5 times the chord length of the guide vane.

[0019] In this way, it can be ensured that the guide vane's change in airflow direction can affect the pressure on the side of the through-hole closer to the first inlet.

[0020] In some embodiments, the projection of the through hole along the axis of rotation of the impeller is all inside the projection of the second outlet along the axis of rotation of the impeller.

[0021] In this way, when the guide vanes are used to change the airflow direction, the pressure on the side of the through hole near the first inlet can be better affected.

[0022] In some embodiments, the number of through holes is the same as the number of airflow channels, and the through holes are connected to the corresponding airflow channels.

[0023] In this way, the air pressure inside the airflow channel and at the first inlet can be balanced as much as possible, while minimizing the impact on the structural strength of the impeller.

[0024] In some embodiments, the through-hole is located between two adjacent blades.

[0025] This allows for a better balance between the air pressure inside the airflow channel and at the first inlet, preventing the formation of vortices inside the airflow channel due to differences in the air pressure balancing speed during the balancing process.

[0026] In some embodiments, the wheel, the wheel cover, and the plurality of blades are integrally formed into a single structure, wherein a sand core is added during the integral forming process to form the through hole.

[0027] Therefore, integral machining helps reduce the machining difficulty of the impeller while ensuring the structural strength of the impeller.

[0028] Another embodiment of the compressor of this application includes the impeller described in any of the above claims.

[0029] In some embodiments, the compressor further includes a diffuser, which includes a first diffuser baffle and a second diffuser baffle. The impeller is disposed between the first diffuser baffle and the second diffuser baffle. The airflow passage further includes a first outlet. A diffuser air passage is formed between the first diffuser baffle and the second diffuser baffle. The first outlet communicates with the diffuser air passage.

[0030] In this way, the diffuser can increase the outlet pressure of the gas while reducing eddies and turbulence in the airflow, thus reducing energy loss.

[0031] In some embodiments, the compressor further includes a wheel cover seal, which is mounted on the first diffuser plate. The wheel cover seal includes a first sealing surface and a second sealing surface is provided on the wheel cover. The gap between the first sealing surface and the second sealing surface is less than a first preset value.

[0032] In this way, the wheel cover seal can seal the gap between the impeller and the first diffuser baffle, preventing the airflow from the first outlet from returning to the first inlet and entering the first inlet or through hole, thus affecting the normal operation of the compressor.

[0033] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0034] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0035] Figure 1 is a cross-sectional view of the impeller according to an embodiment of this application;

[0036] Figure 2 is a schematic diagram of the impeller structure according to an embodiment of this application;

[0037] Figure 3 is a schematic diagram of the compressor according to an embodiment of this application;

[0038] Figure 4 is a front view of the regulating housing of the compressor according to an embodiment of this application;

[0039] Figure 5 is a front view of the regulating housing of a compressor according to another embodiment of this application;

[0040] Figure 6 is a partial structural schematic diagram of the compressor according to an embodiment of this application. Detailed Implementation

[0041] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0042] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0043] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0044] This disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described herein. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0045] Centrifugal compressors are widely used in the refrigeration industry. However, centrifugal compressors can become clogged when the actual flow rate is greater than the design flow rate, and can stall when the actual flow rate is less than the design flow rate. If the flow rate is further reduced and exceeds the stall limit, the centrifugal compressor will become more unstable and surge, which can lead to impeller damage and even damage to the compressor and connected equipment.

[0046] Please refer to Figure 1. The impeller 10 of this embodiment includes a disc 11, a cover 12, and multiple blades 13. The blades 13 connect the disc 11 and the cover 12. The disc 11, the cover 12, and two adjacent blades 13 enclose an airflow channel 14. The airflow channel 14 has a first inlet 141. The cover 12 has multiple through holes 1221, which connect the airflow channel 14 and the first inlet 141.

[0047] The impeller 10 provided in this application has a through hole 1221 on the impeller cover 12 so that the first inlet 141 can communicate with the airflow channel 14. When the actual flow rate of the centrifugal compressor 100 is too high or too low, the through hole 1221 can balance the air pressure inside the airflow channel 14 and at the first inlet 141, thereby avoiding blockage or surge and preventing damage to the compressor 100 and connected equipment.

[0048] Specifically, the impeller 10, also known as the working wheel, is the only component in the compressor 100 that performs work on the gas. When the impeller 10 rotates at high speed with the main shaft, its blades 13 perform work on the gas, giving the gas kinetic energy.

[0049] Referring to Figures 1 and 2, in this embodiment, the impeller 10 mainly consists of three parts: a disc 11, a cover 12, and blades 13. The disc 11 is the main supporting component of the impeller 10, and its shape is typically an axisymmetric disc. In the compressor 100, the center of the disc 11 is connected to the shaft, rotates at high speed with the shaft, and drives the blades 13 to rotate together.

[0050] The wheel cover 12 covers the top of the blade 13 and together with the wheel disk 11 and the blade 13, forms a closed airflow channel 14. The geometry of the wheel cover 12 is also axisymmetric to ensure uniform gas flow within the channel.

[0051] Blade 13 is the main component in impeller 10 that performs work on the gas. Blade 13 is periodically distributed in the circumferential direction and is usually curved. Optionally, there are three main types of blade curvature: backward curved, radial curved, and forward curved.

[0052] The backward-curved blade 13 bends in the opposite direction to the rotation of the impeller 10, and the outlet angle of the blade 13 is less than 90°. This type of blade 13 is common in centrifugal compressors 100 because the backward-curved blade 13 can effectively convert the kinetic energy of the gas into static pressure energy, thereby improving the efficiency of the compressor 100.

[0053] The radial blades 13 have an outlet direction that aligns with the radial direction of the impeller 10, and the outlet angle of the blades 13 is 90°. Radial blades 13 are suitable for some special applications, such as compressors 100 that require higher speeds or lower pressure ratios.

[0054] The forward-curved blade 13 bends in the same direction as the impeller 10 rotates, and the outlet angle of the blade 13 is greater than 90°. Forward-curved blades 13 are rarely used in centrifugal compressors 100 because they cause greater airflow impact losses and friction losses, reducing the efficiency of the compressor 100.

[0055] Optionally, the through hole 1221 can be a round hole, a square hole, or other shapes. Preferably, the through hole 1221 is set as a round hole to facilitate the machining of the through hole 1221.

[0056] In some embodiments, the number of through holes 1221 is the same as the number of airflow channels 14, and the through holes 1221 are connected to the corresponding airflow channels 14.

[0057] In this way, the air pressure inside the airflow channel 14 and at the first inlet 141 can be balanced as much as possible, while minimizing the impact on the structural strength of the impeller 10.

[0058] Specifically, in this embodiment, the number of through holes 1221 can be the same as the number of airflow channels 14, or it can be less or more than the number of airflow channels 14. Preferably, the number of through holes 1221 is equal to the number of airflow channels 14.

[0059] In some embodiments, without affecting the overall structure of the compressor 100, the number of through holes 1221 can be appropriately increased to further improve the pressure balance capability and efficiency.

[0060] In some embodiments, provided that the flow rate fluctuation of the compressor 100 is small, the number of through holes 1221 can be appropriately reduced to further improve the structural strength of the impeller 10.

[0061] It should be noted that during use, the through hole 1221 should not be blocked by foreign objects, so as not to affect the air pressure balance effect and the performance of the compressor 100.

[0062] Please refer to Figures 1 and 2. In some embodiments, the through hole 1221 is located between two adjacent blades 13.

[0063] In this way, the air pressure inside the airflow channel 14 and at the first inlet 141 can be better balanced, avoiding the formation of vortices inside the airflow channel 14 due to different air pressure balancing speeds during the balancing process.

[0064] Specifically, blade 13 includes a suction surface and a pressure surface. The suction surface refers to the curved surface where the fluid impacts blade 13 due to pressure reduction. In detail, when fluid flows over blade 13, due to the rotation and shape design of blade 13, the fluid slows down and experiences pressure reduction on the suction surface. Therefore, the suction surface is the surface where the fluid "attracts" the blade 13, and it is also one of the main areas where the fluid impacts blade 13.

[0065] The pressure surface refers to the surface of the impeller 10 that applies pressure to the liquid when the pressure increases. In the impeller 10 of the compressor 100, the pressure surface is usually the back side or flange side (outer side) of the blades 13, that is, the side opposite to the rotation direction of the impeller 10. When the fluid flows through the pressure surface, the fluid pressure increases due to the squeezing action of the blades 13. Therefore, the pressure surface is the main area where the impeller 10 performs work on the fluid, and it is also the area where the fluid is accelerated and its pressure increased.

[0066] In this embodiment, the through hole 1221 can be disposed close to the suction surface or pressure surface of the blade 13. Preferably, the through hole 1221 should be disposed in the middle of the two blades 13. The through hole 1221 being located in the middle of the suction surface and pressure surface of the blade 13 can ensure that the airflow can obtain a uniform pressure distribution when passing through the blade 13, thereby reducing fluid disturbance and energy loss caused by air pressure differences.

[0067] On the other hand, placing the through hole 1221 between the suction surface and the pressure surface of the blade 13 helps to reduce the deformation or damage of the blade 13 caused by pressure concentration.

[0068] In some embodiments, the wheel cover 12 includes a cover body 121 opposite to the wheel disc 11 and an air intake 122 extending from the cover body 121 in a direction away from the wheel disc 11. A first inlet 141 is formed in the air intake 122. The air intake 122 includes an end face facing away from the cover body 121, and a through hole 1221 is formed on the end face.

[0069] Thus, the through hole 1221 is set on the end face, which facilitates the machining of the through hole 1221.

[0070] Specifically, in this embodiment, the cover 121 is disc-shaped with an opening in the middle, the air inlet 122 is cylindrical, the axis of the air inlet 122 is collinear with the axis of the impeller 10, the air inlet 122 is connected to the opening, and the first inlet 141 is disposed inside the air inlet 122.

[0071] Furthermore, multiple through holes 1221 are evenly arranged around the first inlet 141 along the end face of the air inlet cylinder 122.

[0072] Please refer to Figures 1 and 2. In some embodiments, the through hole 1221 is a straight hole extending along the length of the air inlet cylinder 122.

[0073] Thus, the through hole 1221 is set along the length of the air inlet cylinder 122, which facilitates the machining of the through hole 1221.

[0074] Specifically, in this embodiment, the straight hole design is relatively simple and has little impact on the structural strength of the impeller cover 12, helping to ensure the stability and reliability of the impeller 10 under high pressure and high-speed rotation. The straight hole design is easy to process and manufacture, reducing production costs, and also helps to ensure the accuracy and consistency of the through hole 1221, thereby improving the overall quality of the impeller 10.

[0075] On the other hand, the straight-hole design makes the layout of the through-hole 1221 in the impeller 10 more reasonable, making it easier for the through-hole 1221 to connect with the airflow channel 14 and the first inlet 141, thereby improving the efficiency and stability of the compressor 100. Furthermore, the straight-hole design facilitates maintenance and cleaning. During long-term use, if the through-hole 1221 becomes blocked or damaged, it can be more easily repaired or replaced.

[0076] In some embodiments, the diameter of the through hole 1221 is 50% to 70% of the thickness of the air inlet cylinder 122.

[0077] In this way, the through hole 1221 ensures the structural strength of the impeller 10 while maintaining the function of balancing the air pressure inside the airflow channel 14 and at the first inlet 141.

[0078] Specifically, the through-hole 1221 is used to balance the air pressure at the airflow channel 14 and the first inlet 141. If the diameter is too small, it will restrict the airflow and reduce the balancing effect; if the diameter is too large, it may cause air pressure fluctuations, affecting the stability of the compressor 100. Furthermore, the intake cylinder 122 needs to withstand the airflow pressure, and an excessively large diameter of the through-hole 1221 may weaken its strength. A diameter of 50% to 70% can ensure smooth airflow while maintaining stable air pressure and ensuring the structural strength of the intake cylinder 122.

[0079] On the other hand, through-holes 1221 with a ratio of 50% to 70% are easy to process or integrally molded, and can ensure precision and consistency, making them suitable for mass production. Moreover, the diameter of through-holes 1221 affects airflow velocity and pressure distribution, and a ratio of 50% to 70% helps optimize aerodynamic performance, reduce energy loss, and improve compressor efficiency.

[0080] In this embodiment of the application, the thickness of the air intake cylinder 122 should be greater than 5 mm, so that a through hole 1221 with a diameter of 3 mm can be cast on the wheel cover 12.

[0081] In some embodiments, the wheel 11, wheel cover 12 and multiple blades 13 are integrally machined into a single structure, with a sand core added during the integral machining process to form through holes.

[0082] Thus, integral machining helps reduce the machining difficulty of the impeller 10 while ensuring the structural strength of the impeller 10.

[0083] Specifically, there are various manufacturing processes for the impeller 10, including riveting, milling, welding, brazing, precision casting, and electro-erosion machining. The choice of manufacturing process depends on factors such as the size, shape, and material of the impeller 10. For example, for large impellers 10 or impellers 10 with complex shapes, processes such as precision casting or electro-erosion machining are usually used; for small impellers 10 or impellers 10 with simple shapes, processes such as milling or welding can be used.

[0084] In this embodiment, to reduce the machining difficulty of the impeller 10, the disc 11, the cover 12, and the multiple blades 13 are integrally machined into a single structure. The through hole 1221 is actually cast by adding a sand core to a non-perforated impeller mold.

[0085] Please refer to Figure 3. Another embodiment of the compressor 100 of this application includes the impeller 10 of any of the above-mentioned features. Further, the compressor 100 also includes a housing 20 and an adjusting housing 30. Both the adjusting housing 30 and the impeller 10 are disposed within the housing 20. The adjusting housing 30 is a hollow cylindrical shape and includes a second outlet 32, which is correspondingly disposed with the first inlet 141. The adjusting housing 30 also includes a guide vane 40, which is configured to be movably installed inside the adjusting housing 30 to control the opening degree of the adjusting housing 30.

[0086] Thus, by controlling the opening of the housing 30 through the guide vane 40, the pressure of the first inlet 141 can be adjusted, thereby helping to balance the air pressure inside the airflow channel 14 and at the first inlet 141.

[0087] Specifically, in this embodiment, the adjusting housing 30 is cylindrical and includes a second inlet 31 and a second outlet 32, which are respectively located at both ends of the cylindrical shape.

[0088] There are seven guide vanes 40, which are evenly arranged circumferentially along the inner wall of the regulating housing 30. The opening of the regulating housing 30 is controlled by simultaneously controlling the movement of the seven guide vanes 40.

[0089] Please refer to Figures 4 and 5. In some embodiments, the guide vane 40 is rotatably mounted inside the adjustment housing 30.

[0090] In this way, the guide vane 40 can change the airflow direction while controlling the opening of the regulating housing 30, so as to adjust the pressure on the side of the through hole 1221 near the first inlet 141, thereby controlling the airflow speed between the airflow channel 14 and the first inlet 141 and improving the efficiency of balancing the air pressure inside the airflow channel 14 and at the first inlet 141.

[0091] Specifically, in this embodiment, the guide vane 40 is rotatably mounted on the inner wall of the adjusting housing 30. Furthermore, the guide vane 40 can rotate from 0 to 90° to change the airflow direction and pressure at the first inlet 141 of the impeller 10. As can be easily understood, as shown in Figure 4, the opening of the adjusting housing 30 is at its minimum when the rotation angle of the guide vane 40 is 0°, and as shown in Figure 5, the opening of the adjusting housing 30 is at its maximum when the rotation angle of the guide vane 40 is 90°.

[0092] Taking the reduction of the compressor 100 load as an example, the specific adjustment process is as follows: When the compressor 100 load decreases, the guide vane 40 rotates, causing the opening of the regulating housing 30 to gradually decrease, and making the airflow direction of the first inlet 141 of the impeller 10 the same as the rotation direction of the impeller 10, so that a low-pressure wake region is generated at the inlet of the through hole 1221. Due to the pressure difference, a backflow from the airflow channel 14 to the first inlet 141 is generated in the through hole 1221, and the lower the load, the lower the opening of the guide vane 40, and the greater the backflow of the through hole 1221, thereby reducing the inlet angle of attack of the impeller 10.

[0093] In some embodiments, the guide vane 40 is fan-shaped, and the distance between the second outlet 32 ​​and the impeller 10 in the direction of the impeller 10's rotation axis is less than 1.5 times the chord length of the guide vane 40.

[0094] In this way, it can be ensured that the guide vane 40 can change the airflow direction and affect the pressure on the side of the through hole 1221 near the first inlet 141.

[0095] Specifically, the distance between the second outlet 32 ​​and the impeller 10 in the direction of the impeller 10's rotation axis should be less than 1.5 times the chord length of the guide vane 40, so as to ensure that the self-circulation hole is within the influence range of the low-pressure wake region of the guide vane 40. In the embodiment of this application, the distance between the second outlet 32 ​​and the impeller 10 in the direction of the impeller 10's rotation axis is approximately equal to the chord length of the guide vane 40.

[0096] In some embodiments, the projection of the through hole 1221 along the axis of rotation of the impeller 10 is all inside the projection of the second outlet 32 ​​along the axis of rotation of the impeller 10.

[0097] In this way, when the guide vane 40 changes the airflow direction, it can better affect the pressure on the side of the through hole 1221 near the first inlet 141.

[0098] Specifically, the projection of the through hole 1221 along the rotation axis of the impeller 10 is all inside the projection of the second outlet 32 ​​along the rotation axis of the impeller 10, so as to ensure that the through hole 1221 is within the influence range of the low-pressure wake region of the guide vane 40.

[0099] In this embodiment, a plurality of through holes 1221 are uniformly arranged around the first inlet 141 along the end face of the air inlet cylinder 122. The arrangement of the plurality of through holes 1221 is in a ring shape, and the radius of the ring is smaller than the radius of the second outlet 32 ​​of the adjusting housing 30, so that the projection of the through holes 1221 along the rotation axis of the impeller 10 is all inside the projection of the second outlet 32 ​​along the rotation axis of the impeller 10.

[0100] Referring to Figure 3, in some embodiments, the compressor 100 further includes a diffuser 50, which includes a first diffuser baffle 51 and a second diffuser baffle 52. The impeller 10 is disposed between the first diffuser baffle 51 and the second diffuser baffle 52. The airflow passage 14 further includes a first outlet 142. A diffuser passage 53 is formed between the first diffuser baffle 51 and the second diffuser baffle 52. The first outlet 142 communicates with the diffuser passage 53.

[0101] In this way, diffuser 50 can increase the outlet pressure of the gas while reducing eddies and turbulence in the airflow, thus reducing energy loss.

[0102] Specifically, the diffuser 50 of the compressor 100 is a device that converts kinetic energy into static pressure energy. Its main function is to slow down the high-speed airflow from the impeller 10 and effectively convert this kinetic energy into static pressure energy. Simultaneously, the diffuser 50 also serves to collect and extract gas. In the centrifugal compressor 100, the performance of the diffuser 50 has a significant impact on the overall efficiency of the compressor 100.

[0103] The compressor 100 is composed of a diffuser duct 53 consisting of a first diffuser 51 and a second diffuser 52, wherein the first diffuser 51 is the front diaphragm and the second diffuser 52 is the rear diaphragm.

[0104] Diffusers are generally classified into bladeless diffusers, bladed diffusers, and straight-wall diffusers. Among them, bladeless diffusers have no diffuser blades obstructing the flow channel, have a simple structure, are easy to manufacture, and have no impact losses, but their flow efficiency is relatively low. Bladed diffusers guide the airflow through diffuser blades, which can more effectively convert kinetic energy into static pressure energy and improve flow efficiency, but their structure is relatively complex and may generate additional flow losses.

[0105] The core component of the diffuser 50 is the diffuser duct 53, which is formed by the first diffuser baffle 51 and the second diffuser baffle 52, and the cross-section of the diffuser duct 53 gradually increases. When gas flows out of the impeller 10 and enters the diffuser 50, the gas velocity gradually decreases and the pressure gradually increases due to the expansion of the cross-section of the diffuser duct 53.

[0106] The first diffuser 51 and the second diffuser 52 are the main supporting structures of the diffuser 50, ensuring the stability and shape of the annular channel. The diaphragms are typically made of high-strength materials to withstand the pressure and temperature generated during gas flow.

[0107] In some embodiments, diffuser blades may also be installed between the first diffuser baffle 51 and the second diffuser baffle 52. The diffuser blades convert kinetic energy into static pressure energy more effectively by changing the direction of airflow. The shape, number, and arrangement of the diffuser blades all affect the performance of the diffuser 50.

[0108] Please refer to Figure 6. In some embodiments, the compressor 100 further includes a wheel cover seal 60, which is mounted on the first diffuser 51. The wheel cover seal 60 includes a first sealing surface 61 and a second sealing surface 1222 on the wheel cover. The gap between the first sealing surface 61 and the second sealing surface 1222 is less than a first preset value.

[0109] Thus, the wheel cover seal 60 can seal the gap between the impeller 10 and the first diffuser 51, preventing the airflow from the first outlet 142 from returning to the first inlet 141 and entering the first inlet 141 or the through hole 1221, thus affecting the normal operation of the compressor 100.

[0110] Specifically, in this embodiment, the first sealing surface 61 is the inner wall surface of the wheel cover seal 60, and the second sealing surface 1222 is the outer wall surface of the air inlet cylinder 122. The first preset value is 0.25 mm, that is, the gap between the wheel cover seal 60 and the outer wall of the air inlet cylinder 122 is 0.25 mm, so as to prevent the airflow from the outlet of the impeller 10 from returning to the inlet of the impeller 10 and entering the through hole 1221.

[0111] Furthermore, threads are provided on the first sealing surface 61 to further improve the sealing performance between the first sealing surface 61 and the second sealing surface 1222.

[0112] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0113] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the stated features. In the description of this application, "multiple" means at least two, such as two or three, unless otherwise explicitly specified.

[0114] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. An impeller for use in a compressor, wherein, It includes a wheel, a wheel cover, and multiple blades. The blades connect the wheel and the wheel cover. The wheel, the wheel cover, and two adjacent blades enclose an airflow channel. The airflow channel has a first inlet. The wheel cover has multiple through holes that connect the airflow channel and the first inlet.

2. The impeller according to claim 1, wherein, The wheel cover includes a cover body opposite to the wheel disc and an air intake cylinder extending from the cover body away from the wheel disc. The first inlet is formed in the air intake cylinder, and the air intake cylinder includes an end face facing away from the cover body. The through hole is formed on the end face.

3. The impeller according to claim 2, wherein, The through hole is a straight hole extending along the length of the air inlet cylinder.

4. The impeller according to claim 2, wherein, The diameter of the through hole is 50% to 70% of the thickness of the air inlet cylinder.

5. The impeller according to claim 1, wherein, The compressor also includes a housing and an adjusting housing. The adjusting housing and the impeller are both disposed inside the housing. The adjusting housing is a hollow cylindrical shape and includes a second outlet, which is disposed corresponding to the first inlet. The adjusting housing also includes guide vanes, which are configured to be movably installed inside the adjusting housing to control the opening degree of the adjusting housing.

6. The impeller according to claim 5, wherein, The projection of the through hole along the axis of rotation of the impeller is inside the projection of the second outlet along the axis of rotation of the impeller.

7. The impeller according to claim 5, wherein, The guide vane is rotatably mounted inside the adjustment housing.

8. The impeller according to claim 5, wherein, The guide vane is fan-shaped, and the distance between the second outlet and the impeller in the direction of the impeller's rotation axis is less than 1.5 times the chord length of the guide vane.

9. The impeller according to claim 1, wherein, The number of through holes is the same as the number of airflow channels, and the through holes are connected to the corresponding airflow channels.

10. The impeller according to claim 9, wherein, The through hole is located between two adjacent blades.

11. The impeller according to claim 1, wherein, The wheel, the wheel cover, and the plurality of blades are integrally formed into a single structure. During the integral forming process, a sand core is added to form the through hole.

12. A compressor, wherein, Includes the impeller as described in any one of claims 1-11.

13. The compressor according to claim 12, wherein, The compressor further includes a diffuser, which includes a first diffuser baffle and a second diffuser baffle. The impeller is disposed between the first diffuser baffle and the second diffuser baffle. The airflow passage further includes a first outlet. A diffuser air passage is formed between the first diffuser baffle and the second diffuser baffle. The first outlet is connected to the diffuser air passage.

14. The compressor according to claim 13, wherein, The compressor also includes a wheel cover seal, which is installed on the first diffuser plate. The wheel cover seal includes a first sealing surface and a second sealing surface on the wheel cover. The gap between the first sealing surface and the second sealing surface is less than a first preset value.

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