Diffuser, centrifugal compressor and air compression method

Abstract

The present invention discloses a diffuser, a centrifugal compressor and a gas compression method. The diffuser includes a diffuser body, diffuser main blades and diffuser splitter blades. The numbers of the diffuser main blades and the diffuser splitter blades are both multiple, and they are arranged on the diffuser body at staggered intervals along the axis of the diffuser body; the diffuser main blades extend from the radial end face of the diffuser body to the longitudinal end face, and through the diffuser main blades, integrated radial and axial diffusion is achieved, reducing the radial size of the diffuser. The diffuser splitter blades are arranged on the radial end face of the diffuser body, separating the radial gas flow passage into a first radial passage and a second radial passage, so that when the gas flow enters the diffuser, it first passes through the first radial passage and the second radial passage on the radial end face of the diffuser body, and then gradually merges when turning into the axial gas flow passage, reducing the pressure loss at the turning point, that is, the present invention reduces the gas flow loss in the diffuser.

Description

Technical Field

[0001] The present invention relates to the technical field of gas compression equipment, and in particular to a diffuser, a centrifugal compressor and a gas compression method. Background Art

[0002] Centrifugal compressors have been widely used in small gas turbines and medium and small aero-engines due to their advantages such as high single-stage pressure ratio, wide operating range, simple structure, and high reliability. With the increase in the pressure ratio of centrifugal compressors, the unevenness of the air flow at the outlet of the centrifugal impeller increases, and the air flow velocity also increases, resulting in the Mach number at the inlet of the radial diffuser reaching high subsonic or even supersonic, forming shock waves at the inlet or in the channel of the diffuser, which affects the performance of the centrifugal compressor. At the same time, in order to reduce the frontal area of the engine and increase the thrust-to-weight ratio of the engine, it is necessary to minimize the radial size of the engine. As the outer diameter of the engine decreases, the length of the radial diffuser of the centrifugal compressor decreases, and the diffusion load of the diffuser increases sharply, making it extremely easy for flow separation to occur in the blade channel, resulting in an increase in losses in the diffuser and making the diffuser design more difficult.

[0003] Currently, in centrifugal compressors, a combination of a radial diffuser and an axial diffuser is usually used. The air flow enters the radial diffuser from the outlet of the impeller, then turns 90°, and enters the axial diffuser. Due to the lack of guidance in the turning section and the high outlet velocity of the radial diffuser, the loss in the turning section is large, which in turn affects the performance of the compressor. Moreover, this method of segmented diffusion requires a larger radial size, resulting in a larger size of the compressor. Summary of the Invention

[0004] In view of this, the first object of the present invention is to provide a diffuser, aiming to reduce the air flow loss in the diffuser and reduce the radial size of the diffuser.

[0005] The second object of the present invention is to provide a centrifugal compressor.

[0006] The second object of the present invention is to provide a gas compression method.

[0007] In order to achieve the above first object, the present invention provides the following solution:

[0008] A diffuser, comprising:

[0009] A diffuser body, an installation hole for installing a centrifugal impeller is provided at the axis of the diffuser body;

[0010] Diffuser main blades and diffuser splitter blades, the number of the diffuser main blades and the diffuser splitter blades is multiple, and along the axis of the diffuser body, the multiple diffuser main blades and the diffuser splitter blades are alternately and spacedly arranged on the diffuser body;

[0011] The main diffuser blades extend from the radial end face of the diffuser body to the longitudinal end face, and a connected radial air flow channel and an axial air flow channel are formed by enclosing between adjacent main diffuser blades;

[0012] The diffuser splitter blades are arranged on the radial end face of the diffuser body and divide the radial air flow channel into a first radial channel and a second radial channel.

[0013] In a specific embodiment, the main diffuser blade includes a first wedge portion and a first arc portion integrally formed and connected to the first end of the first wedge portion;

[0014] The end of the wedge angle of the first wedge portion is flush with the hole wall of the mounting hole, and the two side wall surfaces of the first wedge portion are respectively tangent to the two side wall surfaces of the first arc portion;

[0015] The second end of the first arc portion extends a preset length out of the axial end face of the diffuser body, and the parts of adjacent first arc portions extending out of the axial end face of the diffuser body enclose an axial air flow channel.

[0016] In another specific embodiment, the diffuser splitter blade includes a second wedge portion and a second arc portion integrally formed and connected to the first end of the second wedge portion;

[0017] The end of the wedge angle of the second wedge portion is flush with the hole wall of the mounting hole, and the two side wall surfaces of the second wedge portion are respectively tangent to the two side wall surfaces of the second wedge portion, and the second end of the second arc portion is flush with the axial end face of the diffuser body.

[0018] In another specific embodiment, the ratio of the cross-sectional area A at any position of the first radial channel or the second radial channel to the throat cross-sectional area A of the first radial channel or the second radial channel t satisfies the following formula:

[0019]

[0020] wherein, L represents the total arc length of the diffuser splitter blade, l represents the arc length of the diffuser splitter blade from the throat of the first radial channel or the second radial channel to the position where the A cross-section is located, the throat position of the first radial channel or the second radial channel is 0, C0 represents the area change coefficient, and the value ranges from 1 to 5;

[0021] and / or

[0022] The wedge angle of the first wedge portion is greater than or equal to 5° and less than or equal to 10°;

[0023] The wedge angle of the second wedge portion is greater than or equal to 5° and less than or equal to 10°.

[0024] In another specific embodiment, one side wall surface of the diffuser main vane is the suction surface of the main vane, and the other side wall surface is the pressure surface of the main vane;

[0025] One side wall surface of the diffuser splitter vane is the suction surface of the splitter vane, and the other side wall surface is the pressure surface of the splitter vane;

[0026] The suction surface of the diffuser splitter vane is arranged face to face with the pressure surface of the adjacent diffuser main vane on one side, and the pressure surface of the diffuser splitter vane is arranged face to face with the suction surface of the adjacent diffuser main vane on the other side.

[0027] In another specific embodiment, on each of the diffuser main vanes, the connecting surface connecting the suction surface of the main vane and the pressure surface of the main vane is an arc surface, and the connecting surfaces on all the diffuser main vanes are located on the same cylindrical surface.

[0028] In another specific embodiment, the included angle formed by the suction surface of the main vane and the terminal end surface of the first radial channel is greater than or equal to 80°;

[0029] The first radial channel and the second radial channel are respectively arc-transitioned to the axial air flow channel.

[0030] In another specific embodiment, along the direction away from the axis line of the diffuser body, the cross-sectional area of the axial air flow channel gradually increases.

[0031] The various embodiments according to the present invention can be arbitrarily combined as needed, and the embodiments obtained after these combinations are also within the scope of the present invention and are part of the specific embodiments of the present invention.

[0032] For the diffuser provided by the present invention, since the diffuser main vanes extend from the radial end surface of the diffuser body to the longitudinal end surface, and a connected radial air flow channel and axial air flow channel are formed by enclosing between adjacent diffuser main vanes, that is, the integrated pressure expansion in the radial and axial directions is realized through the diffuser main vanes, avoiding the problem of large radial size caused by separately arranging a radial diffuser and an axial diffuser for segmented pressure expansion, and the present invention reduces the radial size of the diffuser.

[0033] In addition, since the diffuser splitter vanes and the diffuser main vanes are arranged at staggered intervals, and the diffuser splitter vanes are only arranged on the radial end face of the diffuser body, the radial air flow passage is divided into a first radial passage and a second radial passage. When the air flow enters the diffuser, it first passes through the first radial passage and the second radial passage on the radial end face of the diffuser body, and then gradually merges when turning into the axial air flow passage, reducing the pressure loss at the turning point, that is, the present invention reduces the air flow loss in the diffuser.

[0034] To achieve the second above-mentioned purpose, the present invention provides the following solution:

[0035] A centrifugal compressor includes a centrifugal impeller and a diffuser as described in any one of the above.

[0036] The centrifugal impeller is rotatably installed in the installation hole of the diffuser, and the centrifugal impeller includes a first blade and a second blade. Along the axis of the centrifugal impeller, the lengths of the first blade and the second blade are different. The numbers of the first blade and the second blade are both multiple, and they are arranged at staggered intervals along the axis of the centrifugal impeller.

[0037] Since the centrifugal compressor provided by the present invention includes the diffuser described in any one of the above, therefore, the beneficial effects possessed by the diffuser are all included in the centrifugal compressor disclosed by the present invention.

[0038] To achieve the third above-mentioned purpose, the present invention provides the following solution:

[0039] A gas compression method includes:

[0040] Providing the centrifugal compressor as described above;

[0041] Starting the centrifugal impeller, making the centrifugal impeller rotate to do work, sucking air along the axis of the centrifugal impeller into the centrifugal impeller and compressing it;

[0042] The air enters the first radial passage and the second radial passage of the diffuser along the radial direction of the centrifugal impeller, turns 90° and then enters the axial air flow passage of the diffuser, and is discharged from the diffuser. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without paying creative labor, other drawings can also be obtained based on these drawings.

[0044] Figure 1Three - dimensional structure schematic diagram of the diffuser provided by the present invention;

[0045] Figure 2 Front - view structure schematic diagram of the diffuser provided by the present invention;

[0046] Figure 3 Rear - view structure schematic diagram of the diffuser provided by the present invention;

[0047] Figure 4 Front - view structure schematic diagram of the centrifugal compressor provided by the present invention;

[0048] Figure 5 Partial sectional view structure schematic diagram of the centrifugal compressor provided by the present invention.

[0049] Among them, Figures 1-5 In:

[0050] Diffuser 100, diffuser main body 101, diffuser main blades 102, diffuser splitter blades 103, mounting holes 101a, radial air flow channels 104, axial air flow channels 105, first radial channels 104a, second radial channels 104b, first wedge portions 102a, first arc portions 102b, second wedge portions 103a, second arc portions 103b, main blade suction surfaces 102c, main blade pressure surfaces 102d, splitter blade suction surfaces 103c, splitter blade pressure surfaces 103d, connection surfaces 102e, centrifugal compressor 1000, centrifugal impeller 200, first blades 201, second blades 202, casing surface 300. Specific embodiments

[0051] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying Figures 1-5 , of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0052] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "top surface", "bottom surface", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated position or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0053] Combined with Figures 1-5As shown in the figure, the first aspect of the present invention provides a diffuser 100 to reduce the air flow loss and the radial size of the diffuser 100.

[0054] As Figures 1-3 shown, the diffuser 100 includes a diffuser body 101, diffuser main blades 102 and diffuser splitter blades 103. Specifically, the diffuser body 101 includes a radially extending disk and an axially extending hub integrally formed and connected, and the outer wall of the radially extending disk is arc-connected to one end of the axially extending hub to reduce the pressure loss of the air flow passing through the diffuser 100.

[0055] An installation hole 101a for installing the centrifugal impeller 200 is provided at the axis center of the diffuser body 101, and the centrifugal impeller 200 and the diffuser body 101 are coaxially arranged.

[0056] In order to avoid interference between the blades of the centrifugal impeller 200 and the diffuser body 101 when the centrifugal impeller 200 rotates, and to facilitate the centrifugal impeller 200 to deliver gas into the diffuser 100, the present invention discloses that a receiving groove is provided on the end face of the diffuser body 101 facing the centrifugal impeller 200, so that the edge of the blade of the centrifugal impeller 200 extends into the receiving groove, and the end face of the edge of the blade of the centrifugal impeller 200 is flush with the end face of the diffuser body 101 facing the centrifugal impeller 200.

[0057] The number of diffuser main blades 102 and diffuser splitter blades 103 is multiple, and along the axis of the diffuser body 101, the multiple diffuser main blades 102 and diffuser splitter blades 103 are staggered and arranged at intervals on the diffuser body 101. Specifically, the multiple diffuser main blades 102 and diffuser splitter blades 103 are staggered and annularly distributed on the diffuser body 101.

[0058] The diffuser main blades 102 extend from the radial end face of the diffuser body 101 to the longitudinal end face, and a connected radial air flow channel 104 and axial air flow channel 105 are formed by enclosing between adjacent diffuser main blades 102. That is, through the diffuser main blades 102, the integrated pressure expansion in the radial and axial directions is realized, avoiding the problem of large radial size caused by separately setting a radial diffuser 100 and an axial diffuser 100 for segmented pressure expansion. The present invention reduces the radial size of the diffuser 100.

[0059] The diffuser splitter vane 103 is arranged on the radial end face of the diffuser body 101, and divides the radial air flow channel 104 into a first radial channel 104a and a second radial channel 104b respectively. The first radial channel 104a and the second radial channel 104b are formed by enclosing between the diffuser splitter vane 103 and two adjacent diffuser main vanes 102 respectively. Dividing the radial air flow channel 104 into the first radial channel 104a and the second radial channel 104b enables the air flow, when entering the diffuser 100, to gradually merge when turning into the axial air flow channel 105 after passing through the first radial channel 104a and the second radial channel 104b on the radial end face of the diffuser body 101 first, reducing the pressure loss at the turning point, that is, the present invention reduces the air flow loss in the diffuser 100.

[0060] It should be noted that the radial end face of the diffuser body 101 refers to the face of the diffuser body 101 along the radial direction and facing the centrifugal impeller 200, that is, the end face of the radial disc away from the axial hub; the axial end face of the diffuser body 101 refers to the face of the diffuser body 101 along the axial direction, that is, the annular outer wall face of the axial hub.

[0061] In some embodiments, the diffuser main vane 102 includes a first wedge portion 102a and a first arc portion 102b. The first end of the first arc portion 102b is integrally formed and connected with the first wedge portion 102a, which is convenient for processing and manufacturing.

[0062] The end of the wedge angle α of the first wedge portion 102a is flush with the hole wall of the mounting hole 101a. The end of the diffuser main vane 102 close to the centrifugal impeller 200 is set as a wedge structure, which provides a guiding effect on the air flow entering the diffuser 100, reduces the resistance to the air flow, and further reduces the loss of gas flow.

[0063] The two side wall surfaces of the first wedge portion 102a are respectively tangent to the two side wall surfaces of the first arc portion 102b. On the one hand, it is convenient for processing and manufacturing the diffuser main vane 102; on the other hand, the first wedge portion 102a and the first arc portion 102b are smoothly connected, further reducing the resistance of the air flow and further reducing the air flow loss.

[0064] The second end of the first arc portion 102b extends a preset length out of the axial end face of the diffuser body 101, and the part of the adjacent first arc portions 102b extending out of the axial end face of the diffuser body 101 encloses the axial air flow channel 105. That is to say, the bending radian of the part of the diffuser main vane 102 enclosing the axial air flow channel 105 is the same as the bending radian of the part of the diffuser main vane 102 enclosing the radial air flow channel 104, which is convenient for processing and manufacturing the diffuser main vane 102.

[0065] Specifically, as Figure 2As shown, the front view projection line of the pressure surface 102d of the main blade is AF, which consists of a straight line segment and a tangent arc segment; the front view projection line of the suction surface 102c of the main blade is AG, which consists of a straight line segment and a tangent arc segment.

[0066] Furthermore, the present invention discloses that the wedge angle α of the first wedge portion 102a is greater than or equal to 5° and less than or equal to 10°. It should be noted that the wedge angle α of the first wedge portion 102a is not limited to the above range value and can also be set to other angle values according to needs.

[0067] In some embodiments, the present invention discloses that the diffuser splitter vane 103 includes a second wedge portion 103a and a second arc portion 103b. The first end of the second arc portion 103b is integrally formed and connected with the second wedge portion 103a, which is convenient for processing and manufacturing.

[0068] The end of the wedge angle β of the second wedge portion 103a is flush with the hole wall of the mounting hole 101a. The end of the diffuser splitter vane 103 close to the centrifugal impeller 200 is set as a wedge structure, which provides a guiding effect on the airflow entering the diffuser 100, reduces the resistance to the airflow, and further reduces the loss of gas flow.

[0069] The two side wall surfaces of the second wedge portion 103a are respectively tangent to the two side wall surfaces of the second wedge portion 103a. On the one hand, it is convenient for processing and manufacturing the diffuser splitter vane 103. On the other hand, the second wedge portion 103a and the second arc portion 103b are smoothly connected, further reducing the resistance of the airflow and further reducing the airflow loss.

[0070] The second end of the second arc portion 103b is flush with the axial end surface of the diffuser body 101, so that after the airflow passes through the first radial channel 104a and the second radial channel 104b, it can converge at the turning point and enter the axial airflow channel 105.

[0071] Specifically, as Figure 2 shown, the front view projection line of the suction surface 103c of the splitter vane is BI, which consists of a straight line segment and a tangent arc segment; the front view projection line of the suction surface 103c of the splitter vane is BJ, which consists of a straight line segment and a tangent arc segment. The throat cross-section BD of the first radial channel 104a and the throat cross-section CE of the second radial channel 104b are calculated and given according to the outlet parameters of the centrifugal impeller 200.

[0072] Furthermore, the present invention discloses that the ratio of the cross-section A at any position of the first radial channel 104a or the second radial channel 104b to the throat cross-section A t of the first radial channel 104a or the second radial channel 104b satisfies the following formula:

[0073]

[0074] Among them, L represents the total arc length of the diffuser splitter vane 103, l represents the arc length of the diffuser splitter vane 103 from the throat of the first radial channel 104a or the second radial channel 104b to the position where the A section is located, the throat position of the first radial channel 104a or the second radial channel 104b is 0, C0 represents the area change coefficient, and the value ranges from 1 to 5.

[0075] As Figure 2 shown, the throat section of the first radial channel 104a refers to the section at BD, and the throat section of the second radial channel 104b refers to the section at CE. When calculating the cross-section at any position of the first radial channel 104a, the total arc length of the diffuser splitter vane 103 refers to the length of BI. When calculating the cross-section at any position of the second radial channel 104b, the total arc length of the diffuser splitter vane 103 refers to the length of BJ.

[0076] Furthermore, the present invention discloses that the wedge angle β of the second wedge portion 103a is greater than or equal to 5° and less than or equal to 10°. It should be noted that the wedge angle β of the second wedge portion 103a is not limited to the above range value and can also be set to other angle values according to needs.

[0077] In some embodiments, one side wall surface of the diffuser main vane 102 is the main vane suction surface 102c, and the other side wall surface is the main vane pressure surface 102d; one side wall surface of the diffuser splitter vane 103 is the splitter vane suction surface 103c, and the other side wall surface is the splitter vane pressure surface 103d.

[0078] The splitter vane suction surface 103c of the diffuser splitter vane 103 is arranged face to face with the main vane pressure surface 102d of the adjacent diffuser main vane 102 on one side, and the splitter vane pressure surface 103d of the diffuser splitter vane 103 is arranged face to face with the main vane suction surface 102c of the adjacent diffuser main vane 102 on the other side. That is to say, the bending directions of the diffuser main vane 102 and the diffuser splitter vane 103 are the same.

[0079] In the present invention, both the radial air flow channel 104 and the axial air flow channel 105 are non-axisymmetric channels, which is convenient for adapting to the non-axisymmetric centrifugal impeller 200.

[0080] In some embodiments, on each diffuser main vane 102, the connecting surface 102e connecting the main vane suction surface 102c and the main vane pressure surface 102d is an arc surface, and the connecting surfaces 102e on all diffuser main vanes 102 are located on the same cylindrical surface, which is convenient for the air flow to be evenly discharged from the diffuser 100.

[0081] In some embodiments, the included angle γ between the suction surface 102c of the main blade and the terminal end surface of the first radial channel 104a is greater than or equal to 80°, that is, the included angle γ between the suction surface 102c of the main blade and the outlet flow surface HI of the first radial channel 104a is greater than or equal to 80°, so as to reduce the flow loss.

[0082] In order to further reduce the air flow loss, the present invention discloses that the first radial channel 104a and the second radial channel 104b are respectively transitioned to the axial air flow channel 105 in an arc shape.

[0083] In some embodiments, along the direction away from the axis line of the diffuser body 101, the cross-section of the axial air flow channel 105 gradually becomes larger, as Figure 3 shown, approximately trapezoidal.

[0084] The present invention has the following advantages:

[0085] (1) Adopting radial and axial integrated diffusion, the turning channel loss is small and the aerodynamic performance is good;

[0086] (2) Both the diffuser main blade 102 and the diffuser splitter blade 103 are composed of simple straight line segments and arc line segments, the flow channel is simple and convenient for machining;

[0087] (3) Adopting non-axisymmetric diffusion design, it can be matched with the large and small blade channels of the centrifugal impeller 200;

[0088] (4) The front ends of both the diffuser main blade 102 and the diffuser splitter blade 103 are wedge-shaped, which can adapt to the supersonic inlet flow and reduce the total pressure loss of the diffuser 100.

[0089] As Figure 4 and Figure 5 shown, in the second aspect of the present invention, a centrifugal compressor 1000 is provided, which includes a centrifugal impeller 200 and a diffuser 100 in any one of the above embodiments.

[0090] The centrifugal impeller 200 is rotatably installed in the installation hole 101a of the diffuser 100, and the centrifugal impeller 200 includes a first blade 201 and a second blade 202. Along the axis of the centrifugal impeller 200, the lengths of the first blade 201 and the second blade 202 are different, and the numbers of both the first blade 201 and the second blade 202 are multiple, and they are arranged staggeredly at intervals along the axis of the centrifugal impeller 200.

[0091] Since the centrifugal compressor 1000 provided by the present invention includes the diffuser 100 in any one of the above embodiments, therefore, all the beneficial effects of the diffuser 100 are included in the centrifugal compressor 1000 disclosed by the present invention.

[0092] The third aspect of the present invention provides a gas compression method, including:

[0093] Providing a centrifugal compressor 1000 as in the above embodiments;

[0094] Starting the centrifugal impeller 200, causing the centrifugal impeller 200 to rotate and do work, sucking air axially along the centrifugal impeller 200 into the centrifugal impeller 200 and compressing it;

[0095] The air enters the first radial channel 104a and the second radial channel 104b of the diffuser 100 radially along the centrifugal impeller 200, turns 90° and then enters the axial air flow channel 105 of the diffuser 100, and is discharged from the diffuser 100.

[0096] It should be noted that the words indicating directions in this article are all set according to the Figure 2 directions in, only for the convenience of expression and without other specific meanings.

[0097] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0098] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

[0099] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0100] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only the specific embodiments. Obviously, according to the content of this specification, many modifications and variations can be made. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A diffuser, characterized in that, Comprising: A diffuser body, an installation hole for installing a centrifugal impeller is provided at the axis of the diffuser body; Diffuser main blades and diffuser splitter blades, the number of both the diffuser main blades and the diffuser splitter blades is multiple, and along the axis of the diffuser body, the multiple diffuser main blades and the diffuser splitter blades are arranged on the diffuser body in an alternating and spaced manner; The diffuser main blades extend from the radial end face of the diffuser body to the longitudinal end face, and a connected radial air flow channel and an axial air flow channel are formed by enclosing between adjacent diffuser main blades; The diffuser splitter blades are arranged on the radial end face of the diffuser body, and the radial air flow channel is divided into a first radial channel and a second radial channel; The ratio of the cross-sectional area A at any position of the first radial channel or the second radial channel to the throat cross-sectional area A of the first radial channel or the second radial channel satisfies the following formula: t ​ Wherein, L represents the total arc length of the diffuser splitter blades, l represents the arc length of the diffuser splitter blades from the throat of the first radial channel or the second radial channel to the position of the A section, the throat position of the first radial channel or the second radial channel is 0, and C0 represents the area change coefficient, with a value of 1 - 5.

2. The diffuser according to claim 1, characterized in that, The diffuser main blades include a first wedge portion and a first arc portion integrally formed and connected to the first end of the first wedge portion; The end of the wedge angle of the first wedge portion is flush with the hole wall of the installation hole, and the two side wall surfaces of the first wedge portion are respectively tangent to the two side wall surfaces of the first arc portion; The second end of the first arc portion extends a preset length out of the axial end face of the diffuser body, and the part where the adjacent first arc portions extend out of the axial end face of the diffuser body encloses an axial air flow channel.

3. The diffuser according to claim 2, characterized in that, The diffuser splitter blades include a second wedge portion and a second arc portion integrally formed and connected to the first end of the second wedge portion; The end of the wedge angle of the second wedge portion is flush with the hole wall of the installation hole, and the two side wall surfaces of the second wedge portion are respectively tangent to the two side wall surfaces of the second wedge portion, and the second end of the second arc portion is flush with the axial end face of the diffuser body.

4. The diffuser according to claim 3, characterized in that, The wedge angle of the first wedge portion is greater than or equal to 5° and less than or equal to 10°; The wedge angle of the second wedge portion is greater than or equal to 5° and less than or equal to 10°.

5. The diffuser according to claim 1, characterized in that, One side wall surface of the diffuser main blade is the main blade suction surface, and the other side wall surface is the main blade pressure surface; One side wall surface of the diffuser splitter blade is the splitter blade suction surface, and the other side wall surface is the splitter blade pressure surface; The splitter blade suction surface of the diffuser splitter blade is arranged face to face with the main blade pressure surface of the adjacent diffuser main blade on one side, and the splitter blade pressure surface of the diffuser splitter blade is arranged face to face with the main blade suction surface of the adjacent diffuser main blade on the other side.

6. The diffuser according to claim 5, characterized in that, On each of the diffuser main blades, the connecting surface connecting the main blade suction surface and the main blade pressure surface is an arc surface, and the connecting surfaces on all the diffuser main blades are located on the same cylindrical surface.

7. The diffuser according to claim 5, characterized in that, The included angle between the main blade suction surface and the terminal end face of the first radial channel is greater than or equal to 80°; The first radial channel and the second radial channel are respectively transitioned to the axial air flow channel in an arc shape.

8. The diffuser according to any one of claims 1 - 7, characterized in that, Along the direction away from the axis line of the diffuser body, the cross-section of the axial air flow channel gradually becomes larger.

9. A centrifugal compressor, characterized in that, It includes a centrifugal impeller and a diffuser as described in any one of claims 1-8; The centrifugal impeller is rotatably installed in the mounting hole of the diffuser, and the centrifugal impeller includes a first blade and a second blade. Along the axial direction of the centrifugal impeller, the lengths of the first blade and the second blade are different. The numbers of the first blade and the second blade are both multiple, and they are arranged staggeredly at intervals along the axis line of the centrifugal impeller.

10. A gas compression method, characterized in that, It includes: Providing a centrifugal compressor as described in claim 9; Starting the centrifugal impeller, so that the centrifugal impeller rotates to do work, sucking air along the axial direction of the centrifugal impeller into the centrifugal impeller and compressing it; The air enters the first radial channel and the second radial channel of the diffuser along the radial direction of the centrifugal impeller, enters the axial air flow channel of the diffuser after a 90° turn, and is discharged from the diffuser.

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