Vane diffuser of centrifugal compressor for inducing uniform pressure distribution

Abstract

The present invention relates to a vane diffuser of a centrifugal compressor for inducing a uniform pressure distribution. In order to uniformly distribute / form a pressure distribution in a discharge-side channel through which air is discharged and moved, and to increase the stall margin by preventing large-scale separation of flows in a flow space part, the centrifugal compressor comprises an impeller (2) and a diffuser (10) having a plurality of vanes (20) formed radially in an annular shape on the edge side of the impeller (2). The vanes (20) are divided into two parts in the longitudinal direction such that upper vanes (21) and lower vanes (25) are formed long the air moving direction and spaced apart from each other while maintaining a separation distance (D) therebetween. Channels (31) are formed between the plurality of vanes (20) such that air moves along same, inlet-side channels (31a) are formed between opposite upper vanes (21) which are adjacent to and face each other, and outlet-side channels (31b) are formed between opposite lower vanes (25) which are adjacent to and face each other.

Description

Vane diffuser of a centrifugal compressor that induces uniform pressure distribution

[0001] The present invention relates to a vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, and more particularly, to a vane diffuser of a centrifugal compressor that induces a uniform pressure distribution by dividing the vanes into two in the longitudinal direction and forming a separation path therebetween so that a boundary fluid layer caused by a stall on the upper surface of an upper vane in an entry-side passage is separated and moved toward the lower vane, thereby maintaining the passage width in the discharge-side passage and uniformly distributing the pressure in the discharge-side passage through which air is discharged, and at the same time, forming an uneven portion by a protrusion and a groove, or an upwardly curved portion and a downwardly curved portion, in a flow space between the vanes on both sides facing each other, so that air passing between the vanes on both sides facing each other moves along the longitudinal direction of the protrusion and the groove, or the upwardly curved portion and the downwardly curved portion, which is formed parallel to the direction of movement, thereby preventing large-scale separation of the flow in the flow space and increasing the stall margin.

[0002] Typically, the impeller of a centrifugal compressor compresses fluid by imparting rotational motion to it using motor power. The optimal impeller shape is determined based on the compressor's design flow rate and compression ratio. Because this impeller shape is a critical factor in determining compressor efficiency and performance, extensive research is being conducted on it.

[0003] As the industrial demand for large-capacity, high-pressure centrifugal compressors has increased recently, the rotational speed of the impeller has increased, and various problems that did not appear in low- to medium-speed impellers have emerged.

[0004] As an example of conventional technology, one of the devices used to increase the output of an engine by performing supercharging to increase the amount of intake air into the cylinder is a turbocharger. In the case of the centrifugal compressor of such a turbocharger, when the rotation speed is fast and the amount of conveyed fluid is small, surge or rotating stall occurs, which limits the operating area of ​​the compressor. At this time, rotating stall is a phenomenon that occurs when the angle of attack of the fluid in a certain area increases due to a decrease in the conveyed fluid, resulting in a decrease in the flow amount or, in severe cases, reverse flow.

[0005] Moreover, if this phenomenon becomes severe, noise is generated due to fluctuations in the flow rate and sudden pressure of the transported fluid, and if it becomes more severe, it causes a serious risk to the stability of the compressor itself. In particular, when operating in the vicinity of the stall line of a general compressor, a rotating stall occurs, causing the boost pressure to oscillate at a frequency of tens to hundreds of Hz.

[0006] The occurrence of such rotating stalls limits the operating range of the compressor, which reduces the operating range of the engine and has a negative effect on fuel efficiency and noise.

[0007] In addition, as shown in FIGS. 1 and 2 illustrating the prior art, a vortex phenomenon occurs when flowing within the flow path (112) between multiple vanes (104) provided on the outer circumference of the impeller on the diffuser (102), and a boundary fluid layer (106) is formed therebetween due to separation of air and stall, and since this boundary layer flow is a strong viscous shear flow with a very low momentum compared to the mainstream, it causes a large pressure loss and a large thermal load on the wall surface of the vane (104). As a result, the pressure recovery is reduced by the boundary fluid layer (106) generated on the wall surface of the vane, and in some cases, a stall occurs.

[0008] In addition, as the occurrence of boundary fluid layers (106) on the walls of both sides of the facing vessel increases and the flow path narrows, the pressure decreases and its recovery becomes impossible, and as a result, the pressure distribution is different at each location in the flow path, causing various problems including vibration and noise.

[0009] In addition, there was a problem in which a vortex phenomenon occurred during flow between the multiple fixed vanes provided on the outer circumference of the impeller, and air separation occurred between them.

[0010] [Prior Art Literature]

[0011] [Patent Document]

[0012] Registered Patent No. 10-2276503

[0013] Accordingly, the present invention was created to eliminate the above-mentioned problems, and the vane diffuser of a centrifugal compressor is focused on and completed as a technical task to induce a uniform pressure distribution by dividing the vane in two in the longitudinal direction and forming a separation path between them so that the boundary fluid layer caused by the stall on the upper surface of the upper vane in the entry-side passage moves away toward the lower vane, thereby maintaining the passage width in the discharge-side passage and uniformly distributing the pressure in the discharge-side passage through which the air is discharged, and forming an uneven portion by means of a protrusion and a groove, or an upwardly curved portion and a downwardly curved portion, in the flow space between the facing vanes on both sides so that the air passing between the facing vanes moves along the longitudinal direction of the protrusion and the groove, or the upwardly curved portion and the downwardly curved portion, which is formed parallel to the direction of movement, thereby preventing large-scale separation of the flow in the flow space and increasing the stall margin.

[0014] In order to achieve the above technical task, the present invention provides a vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, the centrifugal compressor comprising an impeller (2) that rotates around a rotational axis to introduce air inward, and a diffuser (10) having a plurality of vanes (20) formed radially on the edge of the impeller (2) in an annular shape to reduce the movement speed of the introduced air and increase its pressure, wherein the vanes (20) are divided into two in the longitudinal direction and a distance (d) is maintained between them so that an upper vane (21) and a lower vane (25) are formed to be spaced apart along the direction of movement of the air, and a flow path (31) through which air moves is formed between the plurality of vanes (20), wherein an inlet flow path (31a) is formed between the upper vanes (21) on both sides that are adjacent and facing each other, and a discharge flow path (31b) is formed between the lower vanes (25) on both sides that are adjacent and facing each other.

[0015] In addition, a separation path (35) is formed in the space within the distance (d) formed between the upper vane (21) and the lower vane (25), so that the boundary fluid layer (51) caused by the stall occurring on the upper surface (21a) of the upper vane (21) in the entry-side channel (31a) moves toward the lower vane (25), and is partially separated through the separation path (35) and is moved by settling on the upper surface (21a) of the upper vane (21) in the next rotational direction.

[0016] In addition, the boundary fluid layer (51) on the upper surface (21a) of the upper vane (21) is transferred while being reduced due to the separation action in the separation path (35) on the path where the boundary fluid layer (51) moves on the upper surface (25a) of the lower vane (25) in the same flow path (31) in the air movement direction, thereby maintaining the flow path width (L) in the discharge-side flow path (31b) between the facing lower vanes (25), thereby forming a pressure distribution uniformly in the discharge-side flow path (31b) through which the air moves.

[0017] In addition, it is characterized in that the rear end (75) of the lower vane (25) is formed lower than the front end (71) of the upper vane (21) in the direction of air movement on the same path (31) by a gap width (w) in the direction of air departure through the escape route (35).

[0018] In addition, the separation distance (d) formed between the upper vane (21) and the lower vane (25) is characterized by being formed to be 2.5 to 3.5 times larger than the separation width (w) in order to increase the amount of movement of the boundary fluid layer (51) through the escape route (35) and to sufficiently secure the amount of air moving in the exhaust side passage (31b) between the lower vanes (25).

[0019] In addition, it is characterized in that a downward slope (81, 83) is formed in the direction of departure of the lower boundary fluid layer (51) of each of the front end (71) of the upper vane (21) and the rear end (75) of the lower vane (25).

[0020] In addition, the downward slope (81, 83) is characterized by a shape that expands toward the direction of movement of the boundary fluid layer (51).

[0021] In addition, a fluid space (31) is formed between the inner and outer end points (P1, P2) of one side vane (20) and the inner and outer end points (P3, P4) of the other side vane (20) which are arranged nearby, and a number of protrusions (41) and grooves (42) are continuously formed in an uneven shape in the direction from the first inner side surface (L1) connecting the inner and outer end points (P1, P2) of one side vane (20) to the second inner side surface (L2) connecting the inner and outer end points (P3, P4) of the other side vane (20) on the bottom surface of the fluid space (31), and the protrusions (41) and grooves (42) are formed from the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides to the It is characterized by being configured to be formed parallel to the direction of air movement in the direction of the second extension line (E2) connecting the outer end points (P2, P4).

[0022] In addition, it is characterized in that the pressure distribution within the flow space (31) is uniformly distributed as the air passing between the opposing vanes (20) moves along the length of a plurality of grooves (42) formed parallel to the direction of movement.

[0023] In addition, a flow space (31) is formed between the inner and outer end points (P1, P2) of one side vane (20) and the inner and outer end points (P3, P4) of the other side vane (20) which are arranged nearby, and a plurality of upwardly curved portions (45) and downwardly curved portions (46) are continuously intersected and formed in a protruding shape from the first inner side surface (L1) connecting the inner and outer end points (P1, P2) of one side vane (20) to the second inner side surface (L2) connecting the inner and outer end points (P3, P4) of the other side vane (20) on the bottom surface of the flow space (31), and the upwardly curved portions (45) and downwardly curved portions (46) are formed from the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides to the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides. It is characterized in that it is formed parallel to the direction of air movement in the direction of the second extension line (E2) connecting the outer end points (P2, P4), so that the air passing between the facing vanes (20) moves along the length of a plurality of upwardly curved portions (45) and downwardly curved portions (46) formed parallel to the direction of movement, thereby uniformly distributing the pressure distribution within the flow space (31).

[0024] In addition, it is characterized in that a plurality of protrusions (41) and grooves (42) are continuously formed in a rough shape in the direction from the first inner surface (L1) connecting the inner and outer end points (P1, P2) of one vane (20) to the second inner surface (L2) connecting the inner and outer end points (P3, P4) of the other vane (20) on the bottom surface of the flow space (31) in which the plurality of upwardly curved portions (45) and downwardly curved portions (46) are continuously intersected.

[0025] In addition, the protrusions (41) and grooves (42) are formed parallel to the direction of air movement from the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides to the second extension line (E2) connecting the outer end points (P2, P4) of the vanes (20) on both sides, so that the air passing between the facing vanes (20) moves along the longitudinal direction of the plurality of grooves (42) formed parallel to the direction of movement, thereby uniformly distributing the pressure distribution within the flow space (31).

[0026] In addition, the protrusion (41) and the groove (42) are characterized by being formed in a rectangular or trapezoidal shape.

[0027] In addition, the protrusion (41) and the groove (42) are characterized by being formed in a semicircular shape.

[0028] According to the present invention described above, the vane is divided into two in the longitudinal direction and a separation path is formed between them so that the boundary fluid layer caused by the stall occurring on the upper surface of the upper vane in the entry-side passage moves away toward the lower vane, thereby maintaining the passage width in the discharge-side passage and enabling the pressure distribution in the discharge-side passage through which air is discharged to be uniformly distributed.

[0029] In addition, by forming a protrusion and groove portion, or an upwardly curved portion and a downwardly curved portion in the flow space between the facing vanes on both sides, the air passing between the facing vanes moves along the longitudinal direction of the protrusion and groove portion, or the upwardly curved portion and the downwardly curved portion, which is formed parallel to the direction of movement, thereby preventing large-scale separation of the flow within the flow space and increasing the stall margin.

[0030] Figure 1 is an example of a conventional vane diffuser.

[0031] Figure 2 is an example of boundary fluid layer formation on the surface of a vane located on both sides of a conventional technology.

[0032] Figure 3 is a conventional basic structure example for explaining the implementation of a vane diffuser of a centrifugal compressor that induces uniform pressure distribution according to the present invention.

[0033] Figure 4 is a perspective view of an example of a vane diffuser of a centrifugal compressor that induces uniform pressure distribution according to the present invention.

[0034] Figure 5 is an example of an operational state according to the present invention.

[0035] Figures 6 and 7 are modified embodiments of the present invention.

[0036] Figure 8 is an example of another modified embodiment according to the present invention.

[0037] Figure 9 is a graph showing the pressure ratio according to the flow rate according to the present invention.

[0038] Figures 10 to 15 are examples of modified embodiments according to the present invention.

[0039] Hereinafter, specific details for implementing the present invention will be described in more detail with reference to the attached drawings.

[0040] The present invention relates to a vane diffuser of a centrifugal compressor that divides a vane in the longitudinal direction into two and forms a separation path therebetween so that a boundary fluid layer caused by a stall on the upper surface of an upper vane in an entry-side passage moves away toward the lower vane, thereby maintaining the passage width in the discharge-side passage and uniformly distributing the pressure in the discharge-side passage through which air is discharged, and at the same time, forms an uneven portion by a protrusion and a groove, or an upwardly curved portion and a downwardly curved portion, in the flow space between the facing vanes on both sides so that the air passing between the facing vanes moves along the longitudinal direction of the protrusion and the groove, or the upwardly curved portion and the downwardly curved portion, which is formed parallel to the direction of movement, thereby preventing large-scale separation of the flow in the flow space and increasing the stall margin, and is described as follows with reference to FIGS. 3 to 15.

[0041] In order to implement the present invention, a centrifugal compressor is first provided with an impeller (2) that rotates around a rotation axis as shown in FIG. 3 and draws air inward, and a diffuser (10) that is provided in a ring shape on the edge of the impeller (2) and has a plurality of vanes (20) formed radially to increase pressure while reducing the movement speed of the drawn air.

[0042] In a typical centrifugal compressor structure, the pressure increases as the speed of the air moving between multiple vanes slows down, generating compressed air. However, as the air separates in the space between the vanes, the pressure distribution becomes uneven, resulting in diffuser stall.

[0043] Accordingly, in the configuration of the diffuser (10) in which the vane (20) is formed, as shown in (a) of FIGS. 4 and 5, the vane (20) is divided into two in the longitudinal direction, and a distance (d) between them is maintained so that the upper vane (21) and the lower vane (25) are formed spaced apart from each other along the direction of air movement.

[0044] To explain the above configuration in more detail, a path (31) through which air moves is formed between the plurality of vanes (20), and an inlet path (31a) is formed between the upper vanes (21) on both sides that are adjacent and facing each other, and an exhaust path (31b) is formed between the lower vanes (25) on both sides that are adjacent and facing each other.

[0045] And, a separation path (35) is formed in the space within the distance (d) formed between the upper vane (21) and the lower vane (25), so that the boundary fluid layer (51) caused by the stall on the upper surface (21a) of the upper vane (21) in the entry-side channel (31a) moves toward the lower vane (25), and is configured to move by being partially separated through the separation path (35) and settling on the upper surface (21a) of the upper vane (21) in the next slot in the rotational direction.

[0046] According to this above structure, as shown in (b) of Fig. 5, the boundary fluid layer (51) on the upper surface (21a) of the upper vane (21) moves toward the upper surface (25a) of the lower vane (25) in the same flow path (31) in the air movement direction, and the boundary fluid layer (51) is reduced and transferred due to the separation action in the separation path (35), so that the flow path width (L) in the discharge-side flow path (31b) between the facing lower vanes (25) is maintained, thereby allowing the pressure distribution in the discharge-side flow path (31b) through which the air moves to be uniformly distributed.

[0047] This can be seen in more detail through Fig. 7. In order to further reduce the movement amount of the boundary fluid layer (51) within the discharge-side channel (31b) and make the pressure distribution within the discharge-side channel (31b) more uniform, as in Fig. 6 (a), as a modified embodiment of the present invention including Fig. 7, the rear end (75) of the lower vane (25) can be configured to be formed lower than the front end (71) of the upper vane (21) in the air movement direction through the escape path (35) by a gap width (w) in the air departure direction along the same channel (31) as in Fig. 6.

[0048] According to the above structure, as in (b) of FIG. 6, it is possible to minimize the movement amount of the boundary fluidized layer (51) moving to the lower vane (25) by increasing the movement time and the movement amount of the boundary fluidized layer (51) through the above-mentioned departure path (35), and according to the modified embodiment structure as in FIG. 6, by increasing the movement amount of the boundary fluidized layer (51) through the above-mentioned departure path (35), the movement amount of the boundary fluidized layer (51) in the discharge-side passage (31b) can be further reduced, so that the pressure distribution in the discharge-side passage (31b) through which air is discharged can be formed to be more uniformly distributed.

[0049] At this time, the separation distance (d) formed between the upper vane (21) and the lower vane (25) is preferably formed to be 2.5 to 3.5 times larger than the separation width (w) in order to increase the amount of movement of the boundary fluidized layer (51) through the escape route (35) and to sufficiently secure the amount of air moved in the discharge-side path (31b) between the lower vanes (25).

[0050] In Fig. 9, the pressure ratio according to the flow rate of air moving within the discharge-side passage (31b) is shown in a graph compared to the prior art. In the figure, when the rotational speed and driving power of the centrifugal compressor are kept constant, the pressure increases further in the case of the diffuser vane of the present invention. This is because the pressure recovery occurring in the diffuser vane of the present invention increases.

[0051] Meanwhile, as another modified embodiment of the present invention, as shown in FIG. 8, a downward slope (81, 83) is formed in the direction of departure of the boundary fluidized layer (51) in the lower direction of the front end (71) of the upper vane (21) and the rear end (75) of the lower vane (25), thereby increasing the departure speed of the boundary fluidized layer (51) being separated and increasing the amount of separation, thereby minimizing the amount of the boundary fluidized layer (51) moving to the lower vane (25).

[0052] At this time, the downward slope (81, 83) is designed to expand toward the direction of movement of the boundary fluidized layer (51), thereby further increasing the departure speed and departure amount of the boundary fluidized layer (51).

[0053] Meanwhile, a modified embodiment for uniformly distributing the pressure within the exhaust-side flow path to be implemented in the present invention is described below with reference to FIGS. 10 to 15.

[0054] As shown in FIG. 10, a flow space (31) is formed between the inner and outer end points (P1, P2) of one side vane (20) and the inner and outer end points (P3, P4) of the other side vane (20) that are arranged adjacent to each other, and as shown in FIGS. 10 and 11, a number of protrusions (41) and grooves (42) are continuously formed in a rough shape from the first inner surface (L1) connecting the inner and outer end points (P1, P2) of one side vane (20) to the second inner surface (L2) connecting the inner and outer end points (P3, P4) of the other side vane (20) on the bottom surface of the flow space (31), and the protrusions (41) and grooves (42) are formed from the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides. It is formed parallel to the direction of air movement in the direction of the second extension line (E2) connecting the outer end points (P2, P4) of the vane (20), so that the air passing between the opposing vanes (20) moves along the length of a plurality of grooves (42) formed parallel to the direction of movement, thereby uniformly distributing the pressure distribution within the flow space (31).

[0055] In the above structure, the air moved is moved along the longitudinal direction of a plurality of continuously formed protrusions (41) and grooves (42), so that the air is moved evenly over the cross-sectional area of ​​the air movement, and the air is distributed and moved within a plurality of grooves (42), thereby minimizing the shaking of the air.

[0056] At this time, the protrusion (41) and the groove (42) can be formed in a rectangular shape as in (a) of Fig. 11, can be formed in a trapezoidal shape as in (b) of Fig. 11, and can be formed in a semicircular shape as in (c) of Fig. 11.

[0057] Meanwhile, as another embodiment of the present invention, as shown in FIG. 12, a plurality of upwardly curved portions (45) and downwardly curved portions (46) are continuously formed in an uneven shape in the direction from the first inner side (L1) connecting the inner and outer end points (P1, P2) of one vane (20) to the second inner side (L2) connecting the inner and outer end points (P3, P4) of the other vane (20) on the bottom surface of the flow space (31), and the upwardly curved portions (45) and downwardly curved portions (46) are formed parallel to the direction of movement of the air in the direction from the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides to the second extension line (E2) connecting the outer end points (P2, P4) of the vanes (20) on both sides, so that the air passing between the facing vanes (20) is directed in the direction of movement. It is configured so that the pressure distribution within the flow space (31) is uniformly distributed while moving along the longitudinal direction of a plurality of upwardly curved portions (45) and downwardly curved portions (46) formed in parallel.

[0058] Under this structure, as shown in Fig. 13, on the bottom surface of the flow space (31) in which the plurality of upwardly curved portions (45) and downwardly curved portions (46) are continuously formed in an intersecting manner, a plurality of protrusions (41) and grooves (42) are continuously formed in a rough shape from the first inner surface (L1) connecting the inner and outer end points (P1, P2) of one vane (20) to the second inner surface (L2) connecting the inner and outer end points (P3, P4) of the other vane (20), and the protrusions (41) and grooves (42) are formed parallel to the direction of movement of the air from the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides to the second extension line (E2) connecting the outer end points (P2, P4) of the vanes (20) on both sides, so that the facing two sides The air passing between the vanes (20) moves along the longitudinal direction of a plurality of grooves (42) formed parallel to the direction of movement, thereby forming a uniform pressure distribution within the flow space (31).

[0059] At this time, as shown in FIG. 14, the upward curved portion (45) and the downward curved portion (46) can be mutually converted along the direction of movement of air. More specifically, on the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides, the upward curved portion (45) is formed on the inner and outer end points (P1, P2) of one vane (20), and the downward curved portion (46) is formed on the inner and outer end points (P3, P4) of the other vane (20). And, on the second extension line (E2) connecting the inner and outer end points (P3, P4) of the above-mentioned vanes (20) on both sides, a downward curved portion (46) is formed on the inner and outer end points (P1, P2) of one vane (20), and an upward curved portion (45) is formed on the inner and outer end points (P3, P4) of the other vane (20).

[0060] In this structure, the air moving passes through the upward curved portion (45) and then the downward curved portion (46), or passes through the downward curved portion (46) and then the upward curved portion (45), i.e., moves while crossing, so that the pressure distribution of the air is uniformly mixed. At this time, the repeating structure of the upward curved portion (45) and the downward curved portion (46) can be configured to be formed in multiple stages.

[0061] In Fig. 15, a graph is shown measuring the pressure recovery rate over time for uniform distribution of air pressure within the above-mentioned fluid space (31). It can be seen that the pressure recovery rate increases as the configuration becomes more uneven compared to the conventional configuration, and as the configuration becomes more curved and uneven, the centrifugal compressor (A) can be driven more stably.

[0062] According to the vane diffuser of the centrifugal compressor of the present invention, which induces a uniform pressure distribution as described above, the vanes are divided into two in the longitudinal direction and a separation path is formed between them so that the boundary fluid layer due to stall occurring on the upper surface of the upper vane in the entry-side passage is separated and moved toward the lower vane, thereby maintaining the passage width in the discharge-side passage, so that the pressure distribution in the discharge-side passage through which air is discharged is uniformly distributed, and at the same time, the uneven portions by the protrusions and grooves, or the upwardly curved portions and the downwardly curved portions are formed in the flow space between the facing vanes, so that the air passing between the facing vanes moves along the longitudinal direction of the protrusions and grooves, or the upwardly curved portions and the downwardly curved portions, which are formed parallel to the direction of movement, thereby preventing large-scale separation of the flow in the flow space, and increasing the stall margin.

[0063] The present invention described above has been described with reference to one embodiment illustrated in the drawings, but this is merely exemplary, and it should be made clear that various modifications and equivalent other embodiments are possible for those skilled in the art. Therefore, the true technical protection scope of the present invention should be interpreted by the appended claims, and all technical ideas within a scope equivalent thereto should be construed as being included within the scope of the present invention.

Claims

1. An impeller (2) that rotates around a rotation axis and draws air inward, A centrifugal compressor is provided with a diffuser (10) having a plurality of radially formed vanes (20) formed in a ring shape on the edge side of the impeller (2) to reduce the movement speed of the introduced air and increase the pressure. The above vane (20) is divided into two in the longitudinal direction, and the distance (d) between them is maintained so that the upper vane (21) and the lower vane (25) are formed spaced apart along the direction of air movement. A vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, characterized in that a path (31) through which air moves is formed between the plurality of vanes (20), an inlet path (31a) is formed between the upper vanes (21) on both sides that are adjacent and facing each other, and a discharge path (31b) is formed between the lower vanes (25) on both sides that are adjacent and facing each other.

2. In paragraph 1, A vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, characterized in that a separation path (35) is formed in a space within a distance (d) formed between the upper vane (21) and the lower vane (25), and a boundary fluid layer (51) caused by a stall occurring on the upper surface (21a) of the upper vane (21) in the entry-side passage (31a) moves toward the lower vane (25), and is partially separated through the separation path (35) and is moved to settle on the upper surface (21a) of the upper vane (21) in the next rotational direction.

3. In paragraph 2, A vane diffuser of a centrifugal compressor for inducing a uniform pressure distribution, characterized in that the boundary fluid layer (51) on the upper surface (21a) of the upper vane (21) is transferred while being reduced due to a separation action in the separation path (35) on the path in which the boundary fluid layer (51) moves onto the upper surface (25a) of the lower vane (25) in the same flow path (31) in the air movement direction, thereby maintaining the flow path width (L) in the discharge-side flow path (31b) between the facing lower vanes (25), thereby uniformly distributing the pressure distribution in the discharge-side flow path (31b) through which the air moves.

4. In paragraph 2, A vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, characterized in that the rear end (75) of the lower vane (25) is formed lower than the front end (71) of the upper vane (21) in the direction of air movement along the same path (31) as the separation width (w) in the direction of air departure through the escape path (35).

5. In paragraph 2, A vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, characterized in that the gap distance (d) formed between the upper vane (21) and the lower vane (25) is formed to be 2.5 to 3.5 times larger than the gap width (w) in order to increase the amount of movement of the boundary fluidized layer (51) through the escape route (35) and to sufficiently secure the amount of air moved in the discharge-side path (31b) between the lower vanes (25).

6. In paragraph 2, A vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, characterized in that a downward slope (81, 83) is formed in the direction of departure of the lower boundary fluid layer (51) of each of the front end (71) of the upper vane (21) and the rear end (75) of the lower vane (25).

7. In paragraph 6, A vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, characterized in that the downward slope (81, 83) is in a form that expands toward the direction of movement of the boundary fluid layer (51).

8. In paragraph 3, A fluid space (31) is formed between the inner and outer end points (P1, P2) of one side vane (20) and the inner and outer end points (P3, P4) of the other side vane (20) which are arranged adjacent to each other. A vane diffuser of a centrifugal compressor for inducing a uniform pressure distribution, characterized in that a plurality of protrusions (41) and grooves (42) are continuously formed in an uneven shape in the direction from the first inner surface (L1) connecting the inner and outer end points (P1, P2) of one vane (20) to the second inner surface (L2) connecting the inner and outer end points (P3, P4) of the other vane (20) on the bottom surface of the above-mentioned fluid space (31), and the protrusions (41) and grooves (42) are formed parallel to the direction of air movement in the direction from the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides to the second extension line (E2) connecting the outer end points (P2, P4) of the vanes (20) on both sides.

9. In paragraph 8, A vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, characterized in that the pressure distribution within the flow space (31) is uniformly distributed as the air passing between the opposing vanes (20) moves along the longitudinal direction of a plurality of grooves (42) formed parallel to the direction of movement.

10. In paragraph 3, A fluid space (31) is formed between the inner and outer end points (P1, P2) of one side vane (20) and the inner and outer end points (P3, P4) of the other side vane (20) which are arranged adjacent to each other. On the bottom surface of the above-mentioned fluid space (31), from the first inner surface (L1) connecting the inner and outer end points (P1, P2) of one vane (20) to the second inner surface (L2) connecting the inner and outer end points (P3, P4) of the other vane (20), a plurality of upwardly curved portions (45) and downwardly curved portions (46) are continuously formed in an uneven shape in the direction of intersection, and the upwardly curved portions (45) and downwardly curved portions (46) are formed parallel to the direction of movement of air from the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides to the second extension line (E2) connecting the outer end points (P2, P4) of the vanes (20) on both sides, so that the air passing between the facing vanes (20) is formed parallel to the direction of movement by a plurality of upwardly curved portions (45) and A vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, characterized in that it is configured so that the pressure distribution within the flow space (31) is uniformly distributed while moving along the longitudinal direction of the downward curved portion (46).

11. In paragraph 10, A vane diffuser of a centrifugal compressor that induces a uniform pressure distribution, characterized in that a plurality of protrusions (41) and grooves (42) are continuously formed in a rough shape from a first inner surface (L1) connecting the inner and outer end points (P1, P2) of one vane (20) to a second inner surface (L2) connecting the inner and outer end points (P3, P4) of the other vane (20) on the bottom surface of a flow space (31) in which a plurality of upwardly curved portions (45) and downwardly curved portions (46) are continuously intersected.

12. In paragraph 11, The vane diffuser of a centrifugal compressor inducing a uniform pressure distribution is characterized in that the above protrusions (41) and grooves (42) are formed parallel to the direction of air movement from the first extension line (E1) connecting the inner end points (P1, P3) of the vanes (20) on both sides to the second extension line (E2) connecting the outer end points (P2, P4) of the vanes (20) on both sides, so that the air passing between the facing vanes (20) moves along the longitudinal direction of the plurality of grooves (42) formed parallel to the direction of movement, thereby uniformly distributing the pressure distribution within the flow space (31).

13. In paragraph 8 or paragraph 11, A vane diffuser of a centrifugal compressor that induces uniform pressure distribution, characterized in that the above protrusion (41) and groove (42) are formed in a rectangular or trapezoidal shape.

14. In paragraph 8 or paragraph 11, A vane diffuser of a centrifugal compressor that induces uniform pressure distribution, characterized in that the above protrusion (41) and groove (42) are formed in a semicircular shape.

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