Comb tooth seal structure and compressor

Abstract

The application provides a comb seal structure and a compressor. The comb seal structure is applied to a first preset structure and a second preset structure which can rotate relatively, and the comb seal structure comprises a plurality of matching grooves arranged on the first preset structure and a plurality of matching structures arranged on the second preset structure. The comb seal structure and the compressor provided by the application adjust a straight flow path into a broken line shape by using a protrusion and a matching groove, change the gas flow direction to cause certain flow loss, and consume part of the energy of the gas after the gas flows into a cavity, so that most of the gas continues to flow along the inner wall of the cavity under the action of inertia and moves in the reverse pressure gradient under the guidance of the arc structure of the inner wall to consume kinetic energy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealing structure, in particular to a comb seal structure and a compressor. BACKGROUND

[0002] The energy efficiency of a centrifugal compressor is an important indicator for measuring the quality of a compressor. In order to achieve higher energy efficiency, the leakage loss inside the compressor needs to be reduced. The centrifugal compressor is a speed type compressor. A comb is arranged between the rotating part and the fixed part. The fluid passes through the channel composed of many throttling gaps and expansion cavities, and the fluid pressure head is greatly reduced after multiple throttling to make the fluid difficult to leak, so as to achieve the purpose of sealing. Therefore, the comb seal can effectively reduce the leakage loss.

[0003] However, the existing comb seal structure only has a groove on a single structure to generate flow resistance to the airflow. There is a straight airflow path between the high pressure side and the low pressure side of the comb seal structure, so that the comb seal structure still has partial leakage, resulting in poor sealing effect. SUMMARY

[0004] In order to solve the technical problem of poor sealing effect of the comb seal structure in the prior art, a comb seal structure and a compressor are provided, which are provided with a protrusion and a cavity and a matching groove to increase the sealing effect.

[0005] A comb seal structure is applied to a first predetermined structure and a second predetermined structure which can rotate relative to each other. The comb seal structure comprises a plurality of matching grooves arranged on the first predetermined structure and a plurality of matching structures arranged on the second predetermined structure. The matching structure comprises a protrusion and a cavity. The protrusion is located in the matching groove, and a matching gap is formed between the protrusion and the matching groove. The cavity is arranged on one side of the protrusion. The airflow in the matching gap can enter the cavity, and the direction of the airflow entering the cavity and the direction of the airflow flowing out of the cavity have an included angle.

[0006] The direction of the airflow flowing out of the cavity is towards the protrusion and / or the matching groove.

[0007] The cavity has an opening towards the first predetermined structure. The opening comprises a first part close to the protrusion and a second part away from the protrusion. The airflow in the matching gap enters the cavity along the first part, and flows out of the cavity along the second part.

[0008] The profile of the cavity comprises a straight segment and a curved segment, a first end of the straight segment is connected with a first end of the curved segment, a second end of the straight segment constitutes one end of the opening, a second end of the curved segment constitutes the other end of the opening, and the gas flow in the matching gap flows along the straight segment to the curved segment.

[0009] The curved segment is an arc segment, a center of the arc segment is located inside the cavity, and the straight segment is tangent to the first end of the curved segment.

[0010] An angle range of a central angle of the arc segment is 180° to 270°.

[0011] A ratio of the height H of the protrusion to a radius R of the arc segment ranges from 1:1.5 to 1:2.5.

[0012] The matching gap comprises an outflow channel, and a flow direction of the outflow channel is parallel to the straight segment.

[0013] The protrusion has a first side surface, the matching groove has a first side wall, the outflow channel is formed between the first side surface and the first side wall, and a profile of the first side surface is collinear with the straight segment.

[0014] The matching gap further comprises an inflow channel for gas flowing into the matching groove, the protrusion has a second side surface, the matching groove has a second side wall, the inflow channel is formed between the second side surface and the second side wall, and an included angle between the second side surface and the first side surface ranges from 30° to 60°.

[0015] A cross section of the protrusion is a triangle, a top angle of the triangle points to the matching groove, and an angle of the top angle β of the triangle ranges from 30° to 60°.

[0016] A ratio of a width B of the matching gap to the height H of the protrusion ranges from 1:10 to 1:15.

[0017] A compressor comprising the comb seal structure.

[0018] The compressor comprises an impeller and an impeller cover, the impeller is provided with a plurality of the matching grooves, the impeller cover is provided with a plurality of the matching structures, and in the same matching structure, the cavity is located on a side of the protrusion close to the impeller axis.

[0019] The compressor comprises an impeller and a diffuser, the impeller is provided with a plurality of the matching grooves, the diffuser is provided with a plurality of the matching structures, and in the same matching structure, the cavity is located on a side of the protrusion away from the impeller axis.

[0020] The comb seal structure and the compressor provided by the application adjust the straight flow path into a broken line shape by the convex and the matching groove, change the gas flow direction to cause certain flow loss, and consume part of the energy of the gas after the gas flows into the cavity, most of the gas continues to flow along the inner wall of the cavity under the action of inertia and moves in the reverse pressure gradient under the guidance of the arc structure of the inner wall, consumes kinetic energy and also causes the conflict of the flow direction, thereby intensifying the degree of turbulence and further consuming the energy of the fluid, so that the fluid pressure head greatly decreases, and finally the fluid pressure is close to the low pressure side after the consumption of the multi-stage matching structure and the matching groove, that is, the driving force of the fluid flow is close to zero, and the fluid is difficult to flow, so that the purpose of preventing gas leakage is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The structural schematic diagram of the comb seal structure provided by the embodiment of the application is shown in the figure.

[0022] Figure 2 The structural schematic diagram of the comb seal structure provided by the embodiment of the application is shown in the figure.

[0023] Figure 3 The structural schematic diagram of the compressor provided by the embodiment of the application is shown in the figure.

[0024] Figure 4 The partial schematic diagram of A of the figure is shown in the figure. Figure 3 The partial schematic diagram of B of the figure is shown in the figure.

[0025] Figure 5 The partial schematic diagram of B of the figure is shown in the figure. Figure 3 The partial schematic diagram of B of the figure is shown in the figure.

[0026] In the figure:

[0027] 1, first preset structure; 2, second preset structure; 3, matching groove; 4, convex; 5, cavity; 6, matching gap; 51, opening; 52, straight line segment; 53, curved line segment; 31, first side wall; 41, first side surface; 32, second side wall; 42, second side surface; 61, outflow channel; 62, inflow channel; 7, impeller; 8, impeller cover; 9, diffuser. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the application more clear and explicit, the application is further described in detail below by combining the figures and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and do not limit the application.

[0029] As Figures 1 to 5The shown comb seal structure is applied to the first preset structure 1 and the second preset structure 2 which can rotate relatively, and the comb seal structure comprises a plurality of matching grooves 3 arranged on the first preset structure 1 and a plurality of matching structures arranged on the second preset structure 2, the matching structure comprises a protrusion 4 and a cavity 5, the protrusion 4 is located in the matching groove 3, and a matching gap 6 is formed between the protrusion 4 and the matching groove 3, the cavity 5 is arranged on one side of the protrusion 4, the airflow in the matching gap 6 can enter the cavity 5, and the direction of the airflow entering the cavity 5 and the direction of the airflow flowing out of the cavity 5 have an included angle. The linear flow path is adjusted to be a broken line shape by the protrusion 4 and the matching groove 3, the gas flow direction is changed to cause a certain flow loss, and after the gas flows into the cavity 5, a throttling expansion is equivalent to being carried out to consume part of the energy of the gas, most of the gas continues to flow along the inner wall of the cavity 5 under the action of inertia, and moves in the reverse pressure gradient under the guidance of the included angle formed by the inner wall, consumes kinetic energy, and at the same time, a small part of the gas still flows from the high-pressure side to the low-pressure side, the airflow flowing out of the cavity 5 is basically from the low-pressure side to the high-pressure side, the flow directions of the two are opposite, that is, the flow direction conflict is generated, so that the degree of turbulence is intensified, the energy of the fluid is further consumed, and the fluid pressure head is greatly reduced. After the consumption of the multiple matching structures and the matching grooves 3, the fluid pressure finally approaches the low-pressure side, that is, the driving force of the fluid flow approaches zero, and the fluid is difficult to flow, so that the purpose of preventing gas leakage is achieved.

[0030] The direction of the airflow flowing out of the cavity 5 is towards the protrusion 4 and / or the matching groove 3. That is, the airflow flowing out of the cavity 5 can hinder the airflow flowing out of the matching gap 6, so as to intensify the degree of turbulence and achieve the purpose of consuming the energy of the fluid.

[0031] The cavity 5 has an opening 51 towards the first preset structure 1, the opening 51 comprises a first part close to the protrusion 4 and a second part away from the protrusion 4, the airflow in the matching gap 6 enters the cavity 5 along the first part and flows out of the cavity 5 along the second part. Wherein the opening 51 is arranged on the surface of the second preset structure 2 towards the first preset structure 1, the outflowing gas in the matching gap 6 flows to the opening 51 near the protrusion 4 and enters the cavity 5, and then continues to flow along the inside of the cavity 5 under the action of inertia, and finally flows out of the cavity 5 through the second part of the opening 51.

[0032] Specifically, the profile of the cavity 5 includes a straight line segment 52 and a curved line segment 53, the first end of the straight line segment 52 is connected with the first end of the curved line segment 53, the second end of the straight line segment 52 constitutes one end of the opening 51, the second end of the curved line segment 53 constitutes the other end of the opening 51, and the airflow in the matching gap 6 flows along the straight line segment 52 to the curved line segment 53. After flowing out of the matching gap 6, the gas is introduced into the curved line segment 53 along the straight line segment 52, the airflow flows more smoothly into the curved line segment 53, and the inertia of the airflow can make the gas flow out of the second end of the curved line segment 53, thereby changing the direction of the airflow to intensify the turbulent flow.

[0033] The curved line segment 53 is a circular arc segment, the center of the circular arc segment is located inside the cavity 5, that is, the curved line segment 53 is a superior arc, and the change angle of the flow direction of the airflow flowing through the curved line segment 53 can exceed 180°, thereby generating the effect of the conflict of the flow direction of the airflow.

[0034] The size of the center of the circular arc segment to the surface of the second predetermined structure 2 is equal to the radius corresponding to the circular arc segment. Thus, the surface of the second predetermined structure 2 is tangent to the second end of the circular arc segment, so that the direction of the airflow flowing out of the cavity is opposite to the direction from the high-pressure side to the low-pressure side, thereby increasing the hindering effect on the airflow as much as possible.

[0035] Further, the straight line segment 52 is tangent to the first end of the curved line segment 53. The airflow hindering that may be generated when the airflow passes through the connection between the straight line segment 52 and the curved line segment 53 is reduced, and it is ensured that the airflow can flow out of the second end of the curved line segment 53.

[0036] Preferably, the angle range of the central angle of the circular arc segment is 180° to 270°.

[0037] The ratio of the height H of the protrusion 4 to the radius R of the circular arc segment ranges from 1:1.5 to 1:2.5. The height H of the protrusion 4 refers to the maximum size of the protrusion 4 protruding from the surface of the second predetermined structure 2. By limiting the height of the protrusion 4 and the radius of the circular arc segment as much as possible, the influence of the protrusion 4 and the cavity 5 on the airflow is ensured while reducing the processing of the second predetermined structure 2.

[0038] The matching gap 6 includes an outflow channel 61, and the direction of the airflow of the outflow channel 61 is parallel to the straight line segment 52. That is, the airflow flowing out of the matching gap 6 flows in a direction tangent to the first end of the circular arc segment as much as possible, thereby increasing the inertia of the gas entering the circular arc segment, increasing the flow rate of the gas flowing out of the cavity 5, and further increasing the degree of turbulent flow and the energy consumption of the fluid.

[0039] Optionally, the protrusion 4 has a first side surface 41, the mating groove 3 has a first side wall 31, the first side surface 41 and the first side wall 31 form the outflow channel 61, and the profile of the first side surface 41 is collinear with the straight line segment 52.

[0040] The mating gap 6 further comprises an inflow channel 62 for gas flowing into the mating groove 3, the protrusion 4 has a second side surface 42, the mating groove 3 has a second side wall 32, the second side surface 42 and the second side wall 32 form the inflow channel 62, and the included angle between the second side surface 42 and the first side surface 41 ranges from 30° to 60°. The acute-angled flow path suddenly changes the flow direction of the gas, causing certain flow loss and thus increasing the resistance to gas flow.

[0041] Optionally, the protrusion 4 has a triangular cross section, the apex angle of the triangle points into the mating groove 3, and the apex angle β of the triangle ranges from 30° to 60°. Preferably, the central angle is 180°+β.

[0042] The triangle can be a right triangle, one of the right angles of the right triangle is perpendicular to the surface of the second predetermined structure, and the hypotenuse of the right triangle is tangent to the first end of the circular arc segment.

[0043] The mating groove 3 has the same shape as the protrusion 4, so as to ensure that the width B of the mating gap is the same at any position.

[0044] The ratio of the width B of the mating gap to the height H of the protrusion 4 ranges from 1:10 to 1:15. The influence of the protrusion 4 on the gas flow is increased as much as possible.

[0045] As shown in Figures 3 to 5 A compressor comprising the comb seal structure described above.

[0046] During the operation of the impeller 7, the gas is driven by the impeller 7 to move from the axis of the impeller 7 to the edge of the impeller 7, and a high-pressure side is formed at the edge of the impeller 7, while a low-pressure side is formed at the axis of the impeller 7. The compressor comprises the impeller 7 and an impeller cover 8, the impeller 7 is provided with a plurality of mating grooves 3, the impeller cover 8 is provided with a plurality of mating structures, and in the same mating structure, the cavity 5 is located on the side of the protrusion 4 close to the axis of the impeller 7. The high-pressure side gas flow at the edge of the impeller 7 flows from the gap between the impeller 7 and the impeller cover 8 to the low-pressure side at the axis of the impeller 7, so that the cavity 5 is located on the side of the protrusion 4 close to the axis of the impeller 7, thereby limiting the possibility of the high-pressure gas at the edge of the impeller 7 flowing to the axis of the impeller 7.

[0047] In order to improve the compression ratio, the compressor can drive the gas in the way of double-stage impeller 7, that is, a plurality of impellers 7 and corresponding diffusers 9 are arranged along the axis direction of the rotating shaft in sequence, when the impeller 7 is the last stage of the compressor, the back of the impeller 7 is communicated with the exhaust port of the compressor through the gap between the diffuser 9 and the rotating shaft, therefore, a plurality of the matching grooves 3 are arranged on the impeller 7, a plurality of the matching structures are arranged on the diffuser 9, and in the same matching structure, the cavity 5 is located on the side of the protrusion 4 away from the axis of the impeller 7, so as to avoid the gas flowing from the high-pressure side to the low-pressure side on the back of the impeller 7.

[0048] The above-mentioned embodiments only express several embodiments of the present application, the description is more specific and detailed, but it cannot be understood as the limitation of the patent scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A comb-tooth sealing structure, applied to a first preset structure (1) and a second preset structure (2) that can rotate relative to each other, characterized in that: The comb-tooth sealing structure includes multiple mating grooves (3) disposed on the first preset structure (1) and multiple mating structures disposed on the second preset structure (2). Each mating structure includes a protrusion (4) and a cavity (5). The protrusion (4) is located within the mating groove (3), and a mating gap (6) is formed between the protrusion (4) and the mating groove (3). The cavity (5) is disposed on one side of the protrusion (4), and the airflow in the mating gap (6) can enter the cavity (5). The direction of the airflow entering the cavity (5) is at an angle to the direction of the airflow flowing out of the cavity (5). The cavity (5) has an opening (51) facing the first preset structure (1). The opening (51) includes a first part close to the protrusion (4) and a second part away from the protrusion (4). In the first part, the airflow in the fitting gap (6) enters the cavity (5) along the first part and exits the cavity (5) along the second part; the profile of the cavity (5) includes a straight segment (52) and a curved segment (53), the first end of the straight segment (52) is connected to the first end of the curved segment (53), the second end of the straight segment (52) forms one end of the opening (51), and the second end of the curved segment (53) forms the other end of the opening (51). The airflow in the fitting gap (6) flows along the straight segment (52) to the curved segment (53); the fitting gap (6) includes an outlet channel (61), the airflow direction of the outlet channel (61) is parallel to the straight segment (52); the straight segment (52) is tangent to the first end of the curved segment (53).

2. The comb-tooth sealing structure according to claim 1, characterized in that: The airflow from the cavity (5) is directed toward the protrusion (4) and / or the mating groove (3).

3. The comb-tooth sealing structure according to claim 1, characterized in that: The curved segment (53) is an arc segment, the center of which is located inside the cavity (5), and the straight segment (52) is tangent to the first end of the curved segment (53).

4. The comb-tooth sealing structure according to claim 3, characterized in that: The central angle of the arc segment ranges from 180° to 270°.

5. The comb-tooth sealing structure according to claim 3, characterized in that: The ratio of the height H of the protrusion (4) to the radius R of the arc segment is in the range of 1:1.5 to 1:2.

5.

6. The comb-tooth sealing structure according to claim 1, characterized in that: The protrusion (4) has a first side surface (41), the mating groove (3) has a first side wall (31), the outflow channel (61) is formed between the first side surface (41) and the first side wall (31), and the profile of the first side surface (41) is collinear with the straight line segment (52).

7. The comb-tooth sealing structure according to claim 6, characterized in that: The fitting gap (6) further includes an inflow channel (62) for gas to flow into the fitting groove (3), the protrusion (4) has a second side surface (42), the fitting groove (3) has a second side wall (32), the inflow channel (62) is formed between the second side surface (42) and the second side wall (32), and the angle between the second side surface (42) and the first side surface (41) is in the range of 30° to 60°.

8. The comb-tooth sealing structure according to claim 1, characterized in that: The cross-section of the protrusion (4) is triangular, and the apex of the triangle points into the mating groove (3). The angle range of the apex β of the triangle is 30° to 60°.

9. The comb-tooth sealing structure according to claim 1, characterized in that: The ratio of the width B of the fitting gap (6) to the height H of the protrusion (4) is in the range of 1:10 to 1:

15.

10. A compressor, characterized in that: The comb-tooth sealing structure includes any one of claims 1 to 9.

11. The compressor according to claim 10, characterized in that: The compressor includes an impeller (7) and an impeller cover (8). The impeller (7) is provided with a plurality of mating grooves (3), and the impeller cover (8) is provided with a plurality of mating structures. In the same mating structure, the cavity (5) is located on the side of the protrusion (4) close to the axis of the impeller (7).

12. The compressor according to claim 10, characterized in that: The compressor includes an impeller (7) and a diffuser (9). The impeller (7) is provided with a plurality of mating grooves (3), and the diffuser (9) is provided with a plurality of mating structures. In the same mating structure, the cavity (5) is located on the side of the protrusion (4) away from the axis of the impeller (7).

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