Diffuser and compressor

Abstract

The diffuser is suitable for being installed between two stages of compression impellers of the compressor, the diffuser comprises a main body part and a plurality of diffusion blades, the diffusion blades are distributed in the circumferential direction of the main body part at intervals, and the diffusion blades obliquely extend in the axial direction of the main body part; a diffusion flow channel is formed between every two adjacent diffusion blades, the diffusion flow channels are communicated between the previous-stage compressor impeller and the next-stage compressor impeller, overflowing openings are formed in the areas, close to the inlet ends of the diffusion flow channels, of the diffusion blades and / or the main body part, and the overflowing openings are used for communicating every two adjacent diffusion flow channels. According to the diffuser provided by the embodiment of the invention, when air flow enters the diffusion runner, the air flow can flow from one side of the diffusion blade to the other side through the flow passing opening, so that the air flow is prevented from flowing back on one side of the diffusion blade to generate vortex, the stability of the air flow is improved, and the stability of the diffuser is further improved to reduce the surge problem of the centrifugal compressor.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and particularly to a diffuser and a compressor. Background Art

[0002] The operating range of a centrifugal compressor is restricted by surge at low flow rates and blockage at high flow rates. Among them, the internal flow of the compressor becomes unstable at low flow rates, which is the cause of compressor surge. The pressure recovery coefficient of a vaned diffuser is high, so it is commonly used in high-pressure ratio centrifugal compressors. However, its flow instability is also the cause of surge in high-pressure ratio centrifugal compressors.

[0003] The instability of the operation of a centrifugal compressor is usually triggered by the instability of the impeller or the diffuser. For example, unstable air flow easily leads to instability. Therefore, there is room for improvement in how to improve the air flow stability of the diffuser. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a diffuser. The diffusing blades of the diffuser are inclined axially. When air flow enters the diffusing flow channel, the air flow can flow from one side of the diffusing blade to the other side through the flow-through port, avoiding the generation of vortices due to structural obstruction on one side of the diffusing blade, that is, improving the air flow stability, thereby improving the stability of the diffuser and reducing the problem of surge in the centrifugal compressor.

[0005] According to the diffuser of the embodiment of the present invention, the diffuser is adapted to be installed between two-stage compression impellers of a compressor, and the diffuser includes: a main body portion and a plurality of diffusing blades; the plurality of diffusing blades are circumferentially spaced apart along the main body portion, and the diffusing blades are arranged to extend obliquely along the axis of the main body portion. A diffusing flow channel is formed between two adjacent diffusing blades, and the diffusing flow channel communicates between the previous-stage compressor impeller and the next-stage compressor impeller. The diffusing blade and / or the main body portion form a flow-through port in the region near the inlet end of the diffusing flow channel, and the flow-through port is used to communicate two adjacent diffusing flow channels.

[0006] According to the diffuser of the embodiment of the present invention, the diffusing blades are inclined relative to the axis. When the air flow brought by the rotation of a stage of compressor impeller enters between two adjacent diffusing blades, the air flow first contacts one end of a diffusing blade. And because the diffusing blade is axially inclined, the diffusing blade will block the entry of the air flow and form an air flow vortex on the side of the diffusing blade near the inlet end. By providing a flow-through port on the side of the diffusing blade and / or the main body portion near the inlet end, the air flow can flow from one diffusing flow channel to another through the flow-through port, thereby reducing the problem of vortex formation at the inlet end of the air flow, improving the smoothness and stability of the air flow, and reducing the problem of surge in the centrifugal compressor.

[0007] For the diffuser according to an embodiment of the present invention, the diffuser vane is provided with a suction surface and a pressure surface which are oppositely arranged along the circumferential direction of the main body portion, and a groove is formed at one end of the diffuser vane close to the inlet end of the diffuser passage. The groove is recessed from the side close to the main body portion to the side away from the main body portion, and the groove penetrates through the suction surface and the pressure surface to form the flow-through opening.

[0008] For the diffuser according to an embodiment of the present invention, the depth of the groove is 5-10% of the thickness of the diffuser vane.

[0009] For the diffuser according to an embodiment of the present invention, the diffuser vane is configured as a curved structure, at least a part of the pressure surface of the curved structure is arcuately recessed toward the side of the suction surface, and at least a part of the suction surface is arcuately protruded toward the side away from the pressure surface.

[0010] For the diffuser according to an embodiment of the present invention, the suction surface and the pressure surface are configured to be arcuately transitionally connected in the direction away from the inlet end.

[0011] For the diffuser according to an embodiment of the present invention, among adjacent diffuser vanes, the pressure surface of one diffuser vane is adjacent to the suction surface of another diffuser vane and forms the diffuser passage.

[0012] For the diffuser according to an embodiment of the present invention, along the extending direction of the diffuser vane, the width of the diffuser vane close to the inlet end of the diffuser passage is smaller than the width away from the inlet end of the diffuser passage.

[0013] An embodiment of the present invention further provides a compressor, including a previous-stage compressor impeller, a subsequent-stage compressor impeller and the above-mentioned diffuser. The diffuser is a horizontal diffuser, and the previous-stage compressor impeller, the horizontal diffuser and the subsequent-stage compressor impeller are axially spaced apart.

[0014] For the compressor according to an embodiment of the present invention, the previous-stage compressor impeller is provided with a first passage, the subsequent-stage compressor impeller is provided with a second passage, the gas discharged from the previous-stage compressor impeller flows through the first passage to the diffuser passage, and the second passage is communicated with one end of the diffuser passage away from the first passage.

[0015] For the compressor according to an embodiment of the present invention, the first passage extends axially and radially and is communicated with one end of the diffuser passage, and the second passage extends axially and radially and is communicated with the other end of the diffuser passage.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned by practice of the present invention. Brief Description of the Drawings

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 is a schematic structural view of a diffuser according to an embodiment of the present invention;

[0019] Figure 2 is a schematic structural view of a diffuser vane according to an embodiment of the present invention;

[0020] Figure 3 is a partial schematic view of a diffuser vane according to an embodiment of the present invention;

[0021] Figure 4 is a schematic view of the air inlet of a diffuser according to an embodiment of the present invention;

[0022] Figure 5 is a schematic view of a multi-stage compressor according to an embodiment of the present invention.

[0023] Reference Numerals:

[0024] Compressor 100,

[0025] Diffuser 1, main body portion 11, diffuser vane 12, flow-through port 121, pressure surface 122, suction surface 123, bottom of suction surface 1231, diffuser flow channel 13, impeller of previous-stage compressor 2, first channel 21, impeller of subsequent-stage compressor 3, second channel 31, impeller of three-stage compressor 4, inter-stage pipe 5. Detailed Description of the Embodiments

[0026] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where 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 by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0027] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, features defined as "first", "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0028] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] Next, refer to Figures 1 - 5 to describe the diffuser 1 according to an embodiment of the present invention. The diffuser blades 12 are inclined axially. When the air flow enters the diffuser passage 13, the air flow can flow from one side of the diffuser blade 12 to the other side through the flow-through port 121, avoiding the generation of vortices due to structural obstruction on one side of the diffuser blade 12. That is, the stability of the air flow is improved, thereby improving the stability of the diffuser 1 and reducing the problem of surging of the centrifugal compressor.

[0030] As Figures 1 - 5 shown, for the diffuser 1 according to an embodiment of the present invention, the diffuser 1 is adapted to be installed between two-stage compression impellers of the compressor 100, and the diffuser 1 includes: a main body portion 11 and a plurality of diffuser blades 12.

[0031] Among them, the plurality of diffuser blades 12 are circumferentially spaced apart along the main body portion 11, and the diffuser blades 12 are arranged to extend obliquely along the axial direction of the main body portion 11. A diffuser passage 13 is formed between adjacent two diffuser blades 12. The diffuser passage 13 communicates between the previous-stage compressor impeller 2 and the next-stage compressor impeller 3. The diffuser blade 12 and / or the main body portion 11 form a flow-through port 121 at a position close to the inlet end of the diffuser passage 13, and the flow-through port 121 is used to communicate adjacent two diffuser passages 13.

[0032] First, the diffuser vanes 12 are axially inclined relative to the main body 11, which can optimize the air flow path, reduce air flow separation and turbulence; in practice, a plurality of diffuser vanes 12 are arranged at intervals around the main body 11, and a diffuser flow passage 13 is formed between adjacent diffuser vanes 12. When the impeller 2 of the current-stage compressor rotates, the air flow is driven into the diffuser flow passage 13 between the adjacent diffuser vanes 12 of the diffuser 1; as Figure 1 and Figure 3 shown, the diffuser vanes 12 are axially inclined. When the air flow enters the diffuser flow passage 13, since there is an included angle between the air flow and the side of the diffuser vane 12 close to the air inlet end and the air inlet direction, the air flow is locally blocked here. When the air flow contacts the two sides of the diffuser vane 12 along the circumference of the main body 11 and flows along the two sides, vortices are likely to be generated at the side of the diffuser vane 12 close to the inlet end, resulting in unstable air flow; by providing a flow-through opening 121 between the diffuser vane 12 and / or the main body 11 near the inlet end of the diffuser flow passage 13, the air flow can flow from one side of the diffuser vane 12 to the other side, reducing the phenomenon of vortices generated at the position of the diffuser vane 12 close to the inlet end.

[0033] Specifically, the flow-through opening 121 can be provided on the diffuser vane 12, or on the main body 11, or a flow-through opening 121 can be formed by enclosing between the diffuser vane 12 and the main body 11. When the air flow flows from the inlet end to the diffuser flow passage 13, the air flow can flow from the position of the diffuser vane 12 close to the inlet end along the circumference of the main body 11 from one side of the diffuser vane 12 to the other side, thereby reducing the phenomenon of air flow aggregation or vortices appearing at the inlet end of the diffuser vane 12, improving the stability of the diffuser 1, reducing the problem of centrifugal compressor surge, and the inclined design of the diffuser vane 12 relative to the main body 11 combined with the design of the flow-through opening 121 can make the air flow fit better with the two side surfaces of the diffuser vane 12 along the circumference of the main body 11, reducing the air flow separation phenomenon and improving the stability of the air flow.

[0034] That is, a flow-through opening 121 is provided at the position of each diffuser vane 12 close to the inlet end. The flow-through opening 121 allows the air flow to flow from one side of the diffuser vane 12 to the other side along the circumference of the main body 11, and the positions of the multiple flow-through openings 121 of the multiple diffuser vanes 12 are the same along the axis of the main body 11, and the sizes of each flow-through opening 121 can be set to be the same, thereby improving the uniformity of the air flow and further reducing the problem of centrifugal compressor surge.

[0035] In some embodiments, the diffuser vane 12 is provided with a suction surface 123 and a pressure surface 122 which are oppositely arranged along the circumferential direction of the main body portion 11. A groove is formed at one end of the diffuser vane 12 near the inlet end of the diffuser passage 13. The groove is recessed from the side close to the main body portion 11 to the side away from the main body portion 11, and the groove penetrates through the suction surface 123 and the pressure surface 122 to form a flow-through opening 121.

[0036] Referring to Figure 4 As shown, the pressure surface 122 of the diffuser vane 12 refers to the surface on the diffuser vane 12 where the gas is under pressure during flow, and the suction surface 123 refers to the surface on the vane where the fluid is under suction during flow. In the design of the diffuser vane 12, the shapes and surface qualities of the pressure surface 122 and the suction surface 123 need to be precisely calculated and optimized to ensure that the performance of the compressor 100 reaches the best state.

[0037] In the embodiments of the present invention, the distances between two adjacent diffuser vanes 12 are equal and form a plurality of diffuser passages 13 with the same shape. Each diffuser vane 12 is configured to be inclined and curved along the axial direction of the main body portion 11. The flow-through opening 121 is provided at the end of the diffuser vane 12 and is formed by arranging a groove in the diffuser vane 12. The groove penetrates through the suction surface 123 and the pressure surface 122 of the diffuser vane 12. This design method is simple and facilitates the control of the groove depth of the plurality of diffuser vanes 12. That is, when the air flow flows from the inlet end to the diffuser passage 13 formed by the adjacent diffuser vanes 12, part of the air flow can flow along one side of the suction surface 123, and part of the air flow can flow through the flow-through opening 121 to the pressure surface 122. Moreover, the flow-through opening 121 is configured in a groove shape, that is, the flow-through opening 121 can accommodate some air flow, which has a buffering effect on the air flow, reducing the risk of vortex generation on the side of the suction surface 123 due to factors such as the intake angle and the blockage of the air flow, that is, the backflow is reduced, indicating that the air flow loss on the diffuser vane 12 after grooving is reduced, and the stability of the air flow in the diffuser 1 is improved.

[0038] Moreover, as Figure 3 shown, there is an included angle a between the central axis of the groove of the diffuser vane 12 and the central perpendicular line of the groove. When the air flow flows from the inlet end towards the adjacent diffuser passage 13, part of the air flow is blocked by the diffuser vane 12 and a backflow phenomenon occurs. When there is a backflow, the design of the groove at the flow-through opening 121 of the diffuser vane 12 enables the gas at the inlet end to flow more smoothly from the suction surface 123 of the diffuser vane 12 to the pressure surface 122, that is, the groove is inclined towards the side close to the inlet end, which can make the backflow air flow reach the groove more smoothly, and the air flow passes through the flow-through opening 121 formed by the groove to flow from one side of the diffuser vane 12 to the other side, which can play a role in guiding the air flow direction, thereby making the transition of the air flow smoother.

[0039] In some embodiments, the depth of the groove is 5-10% of the thickness of the diffuser vane 12. By limiting the depth of the groove, first, the minimum depth is 5% of the thickness of the diffuser vane 12, which can satisfy the requirement that part of the air flow passes through the suction surface 123 to reach the pressure surface 122, thus avoiding the vortex problem caused by the backflow of the air flow at the suction surface 123. And the occurrence of vortices in the air flow will cause a surge problem in the compressor 100. The depth of the groove can be appropriately increased to 10% of the thickness of the diffuser vane 12, that is, the depth of the groove should not be too deep. If the depth is too deep, more air flow may reach the pressure surface 122 from the suction surface 123, resulting in uneven air flow on both sides of the diffuser vane 12. Therefore, the depth of the groove is set to 10% of the thickness of the diffuser vane 12. For example, in actual design, the depth of the groove can be set to 7%, 8%, etc. of the thickness of the diffuser vane 12.

[0040] In some embodiments, the diffuser vane 12 is configured as a curved structure, and at least part of the pressure surface 122 of the curved structure is concave in an arc shape toward one side of the suction surface 123, and at least part of the suction surface 123 is convex in an arc shape toward the side away from the pressure surface 122.

[0041] First of all, the design of the diffuser vane 12 can effectively control the flow direction of the air flow, reduce the flow loss along the way, and thus improve the working efficiency of the compressor. And by designing the diffuser vane 12 into a curved arc structure, compared with a straight-line type, the path of the air flow can be lengthened, and with the outer periphery designed as an arc, the air will flow more smoothly when passing through the diffuser vane 12, thus reducing the generation of wind resistance.

[0042] In addition, as Figure 4 shown, when the air flow enters the diffuser channel 13 along the gas inlet end, part of the air flow can flow along the surface of the suction surface 123 in the direction away from the inlet end. And since the diffuser vane 12 is provided with a groove on the side close to the inlet end, then part of the air flow can flow from the suction surface 123 to the pressure surface 122 toward the position of the groove, and another part of the air flow can flow along the arc surface of the suction surface 123, that is, it reduces the overload at the front part of the diffuser vane 1. The front part is the end close to the inlet end, and the rear part is the end away from the inlet end. When the overload at the front part of the diffuser vane 12 is large, a large amount of diffusion will occur at the rear part of the suction surface 123, resulting in flow separation and backflow. That is, by setting the groove, the situation of overload at the front part of the diffuser vane 12 is reduced, thereby reducing the separation between the air flow and the rear part of the suction surface 123 and improving the peak efficiency of the compressor.

[0043] In some embodiments, the suction surface 123 and the pressure surface 122 are configured to be connected in an arc transition in the direction away from the inlet end.

[0044] Continue to refer to Figure 4As shown, after the pressure surface 122 and the suction surface 123 are set to have an arc transition, the air flow can flow more smoothly along the suction surface 123 and can also flow along the pressure surface 122. Moreover, the air flow at the transition between the suction surface 123 and the pressure surface 122 is smoother, preventing the air flow from becoming unstable due to a sudden change in direction, and reducing the problem of disordered air flow caused by the excessive separation of the air flow at one end of the suction surface 123 far from the air inlet end. That is, by means of arc transition, the smoothness of the air flow is improved.

[0045] In some embodiments, among adjacent diffuser vanes 12, the pressure surface 122 of one diffuser vane 12 is adjacent to the suction surface 123 of another diffuser vane 12 and forms a diffuser flow passage 13.

[0046] That is, the air inlet end of each diffuser flow passage 13 first faces the suction surface 123 of the diffuser vane 12, and part of the air flow can flow through the suction surface 123 to the pressure surface 122, thereby reducing the load of the air flow on the suction surface 123. That is, at this time, part of the air flow can still flow along the surface of the suction surface 123 to the end far from the gas inlet end, improving the fitting effect between the air flow and the suction surface 123, reducing the separation of the air flow from the suction surface 123, so that the air flow can flow along the set route, and improving the stability of the air flow.

[0047] Both sides of each diffuser flow passage 13 are formed by the suction surface 123 and the pressure surface 122. The pressure surface 122 is the side of the gas on the diffuser vane 12 that is subjected to pressure during flow. When the impeller 2 of the previous stage compressor rotates clockwise, the shape of the corresponding diffuser vane 12 is Figure 4 of the shape. At this time, after the air flow enters the diffuser flow passage 13, it first flows along one side of the suction surface 123 to the diffuser flow passage 13 corresponding to the suction surface 123, and flows through the flow port 121 at the top of the suction surface 123 to another diffuser flow passage 13, improving the air flow stability. When the gas flows through the diffuser 1, it needs to change direction and speed, and this change will cause the generation of pressure and suction. Therefore, the suction surface 123 and the pressure surface 122 are adjacent to make better use of the action of these forces to achieve effective compression of the gas.

[0048] In some embodiments, along the extension direction of the diffuser vane 12, the width of the diffuser vane 12 near the inlet end of the diffuser flow passage 13 is smaller than the width of the end far from the diffuser flow passage 13.

[0049] It should be noted that the diffuser vane 12 in the embodiment of the present invention can be understood as when it works at a positive angle of attack, that is, the diffuser vane 12 at a positive angle of attack. The suction surface 123 is closer to the inlet end of the air flow than the pressure surface 122. When the width of the diffuser vane 12 near the inlet end of the diffuser passage 13 is smaller than the width at the end far from the diffuser passage 13, then due to the wider width at the end far from the diffuser passage 13, for example, the gas flowing along the pressure surface 122 has less influence on the gas flowing along the suction surface 123 at the position of the bottom of the suction surface 1231, preventing the air flow from separating from the bottom of the suction surface 1231 too quickly, that is, reducing Figure 4 the gas separation at the arc of the bottom of the suction surface 1231 in

[0050] During actual design, for example Figure 4 corresponds to when the previous-stage compressor impeller 2 rotates clockwise, Figure 4 the shape of the diffuser vane 12 is at a positive angle of attack. At a positive angle of attack, Figure 4 one end of the diffuser vane 12 near the inlet end inclines towards the right along the axial center line of the main body 11 in

[0051] Then when the previous-stage compressor impeller 2 rotates counterclockwise, the diffuser vane 12 of the diffuser 1 can be designed at a negative angle of attack, which is equivalent to changing the shape of the diffuser vane 12 near the inlet end, making the diffuser vane 12 near the inlet end incline towards the left along the axial center line of the main body 11. At this time, the intake air directly contacts the pressure surface 122. When the diffuser 1 operates at a negative angle of attack, the air flow sucks a part of the fluid in the end-wall boundary layer at the pressure surface 122 of the diffuser vane 12, thereby delaying the separation of the air flow at the pressure surface 122. The design of the slotted diffuser vane 12 also improves the peak efficiency of the compressor.

[0052] The embodiment of the present invention also proposes a compressor 100, which includes a previous-stage compressor impeller 2, a subsequent-stage compressor impeller 3, and the above-mentioned diffuser 1. The diffuser 1 is a horizontal diffuser 1, and the previous-stage compressor impeller 2, the horizontal diffuser 1, and the subsequent-stage compressor impeller 3 are axially spaced apart.

[0053] Refer to Figure 5As shown, the previous-stage compressor impeller 2, the horizontal diffuser 1, and the subsequent-stage compressor impeller 3 are axially spaced apart. The main functions of the previous-stage compressor impeller 2 and the subsequent-stage compressor impeller 3 are to compress the gas into a high-pressure state by rapid rotation. The previous-stage compressor impeller 2 and the subsequent-stage compressor impeller 3 generate centrifugal force through rotational power. For example, the previous-stage compressor impeller 2 sucks in the gas and rotates in one direction through the previous-stage compressor impeller 2 to form a high-speed air flow, thus achieving the compression effect. At this time, the air flow enters the horizontal diffuser 1, and the horizontal diffuser 1 converts the kinetic energy of the gas into pressure energy. The horizontal diffuser 1 is arranged at the outlet of the previous-stage compressor impeller 2, and the kinetic energy of the gas is converted into pressure energy by deceleration, thereby further increasing the pressure of the gas. The design of the horizontal diffuser 1 can make the gas flow more smoothly, reduce the surging phenomenon of the compressor 100, and reduce the flow loss and improve the pressure increase efficiency.

[0054] However, there are significant differences between the previous-stage compressor impeller 2 and the subsequent-stage compressor impeller 3 of the compressor 100 in terms of diameter, rotational speed, and compression ratio. For example, the diameter of the previous-stage compressor impeller 2 can be larger, the rotational speed is slower, and the compression ratio of the gas is relatively low; while the diameter of the subsequent-stage compressor impeller 3 is smaller, the rotational speed is faster, and the compression ratio of the gas is relatively high. That is, the gas first undergoes preliminary compression through the previous-stage compressor impeller 2, and then the compressed gas is pressurized through the horizontal diffuser 1. The pressurized gas can continue to flow to the inlet of the subsequent-stage compressor impeller 3, thereby achieving further compression of the gas.

[0055] Thus, by setting the horizontal diffuser 1, miniaturization is achieved, making the structure between the previous-stage compressor impeller 2 and the subsequent-stage compressor impeller 3 more compact and the flow more stable.

[0056] In some embodiments, the previous-stage compressor impeller 2 is provided with a first channel 21, and the subsequent-stage compressor impeller 3 is provided with a second channel 31. The gas discharged from the previous-stage compressor impeller 2 flows through the first channel 21 to the diffuser flow channel 13, and the second channel 31 communicates with one end of the diffuser flow channel 13 away from the first channel 21.

[0057] In practice, referring to Figure 5As shown in the figure, the first channel 21 is arranged inside the impeller 2 of the previous-stage compressor. When the intake air enters the first channel 21, it flows along the first channel 21, enabling the gas to gradually reach the gas inlet end of the horizontal diffuser 1. Then the gas can enter the diffuser flow path 13 of the horizontal diffuser 1. That is, the gas is preliminarily compressed through the first channel 21 of the impeller 2 of the previous-stage compressor. Moreover, the structural shape design of the first channel 21 enables the gas to enter the horizontal diffuser 1 more smoothly while being compressed. Additionally, when the gas enters the second channel 31 of the impeller of the subsequent-stage compression through the diffuser flow path 13 of the horizontal diffuser 1, the second channel 31 is directly opposite to the diffuser flow path 13, thereby improving the smoothness of the air flow. And through the impeller 3 of the subsequent-stage compressor, further compression of the gas can be achieved to compress the gas to the required state.

[0058] Certainly, in actual design, a three-stage compressor impeller 4 can also be continuously arranged behind the impeller 3 of the subsequent-stage compressor. That is, the impeller 2 of the previous-stage compressor is the first-stage compressor impeller, the impeller 3 of the subsequent-stage compressor is the second-stage compressor impeller, and a three-stage compressor impeller 4 is also arranged behind the second-stage compressor impeller. The three-stage compressor impeller 4 and the second-stage compressor impeller 100 are connected through an inter-stage pipe 5, thereby making the design of the air flow channel more flexible, that is, the structure setting of the compressor 100 is more flexible.

[0059] In some embodiments, the first channel 21 extends axially and radially and is connected to one end of the diffuser flow path 13. The second channel 31 extends axially and radially and is connected to the other end of the diffuser flow path 13.

[0060] Continue to refer to Figure 5 As shown in the figure, while the first channel 21 extends axially, it also extends radially. The second channel 31 is configured to extend radially and axially while of the impeller 3 of the subsequent-stage compressor. Moreover, the transition between the radial and axial directions of the first channel 21 is an arc transition, and the transition between the radial and axial directions of the second channel 31 is also an arc transition, reducing the friction and turbulence of the gas in the channel, thereby improving the compression efficiency and reducing energy consumption. And the design of the first channel 21 enables the gas to flow along a specific path, that is, enables the gas to flow to a position opposite to the diffuser flow path 13, thereby improving the compression efficiency of the gas. At the same time, the design of the second channel 31 also facilitates the gas after being diffused to flow directly into the second channel 31 of the impeller 3 of the subsequent-stage compressor after flowing out through the diffuser flow path 13, and the gas can flow along the second channel 31, enabling the impeller 3 of the subsequent-stage compressor to further compress the gas.

[0061] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0062] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A diffuser, characterized in that: The diffuser is suitable for being installed between two-stage compression impellers of a compressor, and the diffuser comprises: Main body; A plurality of diffuser blades are distributed at intervals along the circumference of the main body, and the diffuser blades are arranged to extend obliquely along the axial direction of the main body, a diffuser flow channel is formed between two adjacent diffuser blades, the diffuser flow channel is connected between the previous stage compressor impeller and the next stage compressor impeller, and the diffuser blades and / or the main body are formed with a flow port in an area close to the inlet end of the diffuser flow channel, and the flow port is used to connect two adjacent diffuser flow channels.

2. The diffuser according to claim 1, characterized in that The diffuser blade is provided with a suction surface and a pressure surface which are arranged opposite to each other along the circumferential direction of the main body, and a groove is formed at one end of the diffuser blade close to the inlet end of the diffuser flow channel, and the groove is recessed from a side close to the main body to a side away from the main body, and the groove passes through the suction surface and the pressure surface to form the flow port.

3. The diffuser according to claim 2, characterized in that The depth of the groove is 5-10% of the thickness of the diffuser blade.

4. The diffuser according to claim 2, characterized in that The diffuser blade is configured as a curved structure, wherein at least a portion of the pressure surface of the curved structure is arc-shaped and concave toward a side of the suction surface, and at least a portion of the suction surface is arc-shaped and convex toward a side away from the pressure surface.

5. The diffuser according to claim 2, characterized in that The suction surface and the pressure surface are configured to be connected in an arc-shaped transition in a direction away from the inlet end.

6. The diffuser according to claim 2, characterized in that In the adjacent diffuser blades, the pressure surface of one diffuser blade and the suction surface of another diffuser blade are adjacent to each other and form the diffuser flow channel.

7. The diffuser according to claim 1, characterized in that Along the extension direction of the diffuser blade, the width of the diffuser blade at an inlet end close to the diffuser flow channel is smaller than the width of the diffuser blade at an inlet end far from the diffuser flow channel.

8. A compressor, characterized in that: It comprises a front-stage compressor impeller, a rear-stage compressor impeller and the diffuser according to any one of claims 1 to 7, wherein the diffuser is a horizontal diffuser, and the front-stage compressor impeller, the horizontal diffuser and the rear-stage compressor impeller are spaced apart along the axial direction.

9. The compressor according to claim 8, characterized in that The previous compressor impeller is provided with a first channel, and the next compressor impeller is provided with a second channel. The gas compressed by the previous compressor impeller flows to the diffuser flow channel through the first channel, and the second channel is connected to an end of the diffuser flow channel away from the first channel.

10. The compressor according to claim 9, characterized in that The first channel extends in the axial direction and in the radial direction and is communicated with one end of the diffuser flow channel, and the second channel extends in the axial direction and in the radial direction and is communicated with the other end of the diffuser flow channel.

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