Compressor blade, impeller and high-temperature and high-pressure steam compressor

Abstract

The invention provides a compressor blade, an impeller and a high-temperature and high-pressure steam compressor, the compressor blade comprises a body, the body is provided with a working face and a non-working face which are oppositely arranged, and the body is provided with a buffer part in the direction, facing the non-working face, of the outlet tail edge of the working face; therefore, secondary flow loss and separation loss at an outlet of the tail edge of the body are reduced. The invention further provides a compressor impeller which comprises the compressor blade. According to the compressor blade, the buffer part is arranged at the outlet tail edge of the working surface of the body in the direction towards the non-working surface, so that the normal momentum between the working surface and the non-working surface is reduced, the secondary flow loss and separation loss at the outlet position of an impeller are reduced, and the working efficiency of the impeller is improved; and meanwhile, the wake loss of the trailing edge of the blade can be reduced, dynamic and static interference between the impeller and a static part behind the impeller is reduced, and airflow pressure pulsation is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal compressors, and in particular to a compressor blade, an impeller and a high-temperature and high-pressure steam compressor. Background Art

[0002] For centrifugal compressors, there are separation losses and secondary flow losses inside the impeller, which are manifested in aerodynamic form as vortices formed inside the impeller. Eliminating separation losses and secondary flow losses is beneficial to improving the efficiency of the impeller.

[0003] In actual aerodynamic analysis, vortices are prone to appear near the wheel cover at the impeller outlet, which corresponds to secondary flow and separation loss, seriously affecting the working efficiency of the impeller.

[0004] Based on this, the inventor of the present application proposes a compressor blade, an impeller and a high-temperature and high-pressure steam compressor in order to solve the above-mentioned technical problems. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of separation loss and secondary flow loss in the impeller in the prior art, and to provide a compressor blade, an impeller and a high-temperature and high-pressure steam compressor.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] The present invention provides a compressor blade, which is characterized by comprising:

[0008] The body has a working surface and a non-working surface arranged oppositely. The body is provided with a buffer portion at the outlet trailing edge of the working surface in the direction toward the non-working surface to reduce the secondary flow loss and separation loss at the outlet of the body trailing edge.

[0009] According to an embodiment of the present invention, the buffer portion is arc-shaped at the outer edge of the outlet trailing edge of the body.

[0010] According to an embodiment of the present invention, the thickness of the buffer portion decreases gradually along the direction from the center position of the body to the outlet trailing edge.

[0011] According to one embodiment of the present invention, the size range of the buffer portion is: 1 / 80D2 to 1 / 40D2; wherein D2 is the outer diameter of the impeller corresponding to the body.

[0012] According to an embodiment of the present invention, the buffer portion is planar at the outlet trailing edge of the working surface.

[0013] According to an embodiment of the present invention, the thickness of the buffer portion decreases gradually along the direction from the center position of the body to the outlet trailing edge.

[0014] According to an embodiment of the present invention, the buffer portion is a notch formed on the body at the outlet trailing edge of the working surface.

[0015] According to an embodiment of the present invention, the notch runs through the working surface and the non-working surface.

[0016] The present invention also provides a compressor impeller, which is characterized in that it includes:

[0017] Roulette;

[0018] wheel covers;

[0019] A plurality of compressor blades as described above are located between the wheel disc and the wheel cover and are connected to the wheel disc and the wheel cover respectively.

[0020] According to an embodiment of the present invention, part or all of the plurality of compressor blades are provided with a buffer portion at the outlet trailing edge of the working surface.

[0021] The present invention also provides a high-temperature and high-pressure steam compressor, which is characterized in that it includes at least one compressor impeller as described above.

[0022] According to one embodiment of the present invention, the number of the compressor impellers is at least six, and the steam temperature obtained by compression by the six compressor impellers is at least 530° C. and the steam pressure is at least 11.5 MPa.

[0023] The positive and progressive effects of the present invention are:

[0024] The compressor blade of the present invention has a buffer portion provided at the outlet trailing edge of the working surface of the main body in the direction of the non-working surface, thereby reducing the normal momentum between the working surface and the non-working surface, thereby reducing the secondary flow loss and separation loss at the impeller outlet position, and improving the working efficiency of the impeller.

[0025] At the same time, it can also reduce the trail loss of the blade trailing edge, reduce the dynamic and static interference between the impeller and the static parts behind it, and reduce the airflow pressure pulsation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0027] Figure 1 It is a schematic structural diagram of the compressor impeller of the present invention;

[0028] Figure 2 It is a schematic diagram of the matching structure of the centrifugal compression blade and the wheel disc of the present invention;

[0029] Figure 3 for Figure 2 A schematic diagram of the enlarged structure at A in the middle;

[0030] Figure 4 for Figure 2 A schematic diagram of another embodiment of the enlarged structure at A in the figure.

[0031] 1. Main body; 11. Working surface; 12. Non-working surface; 13. Buffer part; 14. Notch;

[0032] 2. Impeller; 21. Wheel cover; 22. Wheel disc. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0035] The working principle of a centrifugal compressor is that after the gas enters the impeller of the centrifugal compressor, under the action of the blades on the impeller, it rotates at high speed with the impeller, and at the same time flows to the impeller outlet under the action of the rotating centrifugal force and is subjected to the expansion pressure of the impeller.

[0036] Its pressure energy and kinetic energy are both improved. After the gas enters the diffuser, the kinetic energy is further converted into pressure energy. The gas then flows into the next-stage impeller through the bend and the return flow device for further compression, which increases the pressure and speed of the gas so that the gas pressure reaches the working pressure required by the process.

[0037] Secondary flow loss refers to: on the cross section perpendicular to the flow direction of the airflow, since the pressure on the working surface is greater than the pressure on the non-working surface, the airflow on the working surface flows to the non-working surface, thus generating vortices and causing losses. The secondary flow loss increases with the increase of the pressure ratio in the impeller.

[0038] Separation loss is mainly caused by separation caused by diffusion and impact. Diffusion refers to the process of diffusion of air in other components except the suction chamber when the air flow passes through the compressor flow channel. If the diffusion degree is too large, the channel area changes suddenly, the channel turns sharply, etc., gas separation will occur in the boundary layer, generating vortexes and leading to large separation losses. Generally, the diffusion degree of the blade channel is limited by adjusting the diffusion angle.

[0039] The separation loss caused by impact occurs when the operating conditions change. When the compressor is operating under the designed operating conditions, the relative velocity at the impeller inlet flows along the tangential direction of the blade inlet. When the flow rate increases or decreases, the relative velocity is inconsistent with the blade inlet, especially when the flow rate is reduced to a certain extent. The separation occupies the entire tangential direction and causes separation loss, and surge occurs in the channel.

[0040] Reference Figures 1 to 4 The present invention proposes a compressor impeller 2, comprising a wheel disc 22, a wheel cover 21 and a plurality of compressor blades, wherein the plurality of compressor blades are arranged between the wheel disc 22 and the wheel cover 21 and are connected to the wheel disc 22 and the wheel cover 21 respectively.

[0041] It can be seen that multiple compressor blades are evenly spaced along the outer circumference of the wheel disc 22. During the operation of the compressor, vortices are easily generated at the outlet of the compressor blades and close to the wheel cover 21, and the higher the pressure, the more obvious the vortex. Eliminating the vortex can eliminate secondary flow losses and separation losses, thereby achieving the effect of improving efficiency.

[0042] The present invention also provides a high-temperature and high-pressure steam compressor, comprising at least one compressor impeller as described above.

[0043] Specifically, in order to meet the predetermined high-temperature and high-pressure steam outlet parameters, the number of compressor impellers in the present invention is at least six, and the steam temperature output after six-stage compression is at least 530° C. and the steam pressure is at least 11.5 MPa.

[0044] The present invention does not make major adjustments to the material and structure of the impeller 2, but makes adjustments to the blade structure, thereby improving the efficiency of the steam compressor to meet the use requirements under high temperature and high pressure conditions.

[0045] Specifically, a nuclear power plant generates a large amount of steam during the power generation process, and the steam generally needs to be cooled, which not only wastes thermal energy but also wastes a large amount of circulating cooling water.

[0046] It can be seen that the steam parameters required by the chemical industry are relatively high, generally steam pressure 11.5MPa and steam temperature 530℃.

[0047] The present invention can reuse the low-parameter steam generated by a nuclear power plant through at least six stages of compression, and the high-temperature and high-pressure steam obtained after compression can be directly applied to the chemical industry, so that clean energy can also be obtained in high-parameter fields.

[0048] Please refer to Figure 2 and Figure 3 The compressor blade proposed in the present invention includes a body 1, which has a working surface 11 and a non-working surface 12 arranged opposite to each other. The body 1 is provided with a buffer portion 13 at the outlet trailing edge of the working surface 11 in the direction toward the non-working surface 12 to reduce the secondary flow loss and separation loss at the outlet of the trailing edge of the body 1.

[0049] It should be noted that a plurality of compressor blades are arranged between the wheel disc 22 and the wheel cover 21, and each of the plurality of compressor blades may be provided with a buffer portion 13 at the outlet trailing edge of the working surface 11, or a portion of the compressor blades may be selected to provide a buffer portion 13 at the outlet trailing edge of the working surface 11, which is not limited here.

[0050] The buffer portion 13 is provided at the outlet trailing edge of the compressor blade working surface to reduce the normal momentum between the working surface 11 and the non-working surface 12, thereby reducing the secondary flow and separation loss at the outlet position of the impeller 2, improving the working efficiency of the impeller 2, and at the same time reducing the trail loss of the blade trailing edge, reducing the dynamic and static interference between the impeller 2 and the stationary parts behind it, and reducing the airflow pressure pulsation.

[0051] In one embodiment, the buffer portion 13 is arc-shaped at the outlet trailing edge of the working surface 11 .

[0052] Specifically, the thickness of the buffer portion 13 decreases gradually along the direction from the center of the working surface 11 to the outlet trailing edge.

[0053] In the actual processing, the buffer portion 13 may be formed by chamfering the outlet trailing edge of the working surface 11, or may be integrally processed during the production of the compressor blades, which is not limited here.

[0054] When a portion of the body 1 is cut off at the outlet trailing edge of the working surface 11, the normal momentum of the working surface 11 and the non-working surface 12 at the outlet trailing edge is reduced, thereby reducing the secondary flow and separation loss at the outlet of the impeller 2, which is beneficial to improving the working efficiency of the impeller 2.

[0055] Furthermore, the size range of the buffer portion 13 is: 1 / 80D2 to 1 / 40D2; wherein D2 is the outer diameter of the impeller 2 corresponding to the body 1.

[0056] It has been determined through multiple tests that, within the above-selected size range, the buffer portion 13 can achieve the purpose of effectively reducing secondary flow and separation losses without affecting the structural rigidity of the compressor blade itself.

[0057] In some other embodiments, the buffer portion 13 is flat at the outlet trailing edge of the working surface 11. Meanwhile, the thickness of the buffer portion 13 decreases gradually along the direction from the center of the working surface 11 to the outlet trailing edge.

[0058] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right, high, low", "lateral, vertical, perpendicular, horizontal" and "center, top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present application. The directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0059] It can be seen that the center of the body 1 is the axial center position of the impeller 2, the body 1 is extended radially outward along the impeller 2, and the edge of the body 1 away from the center is the trailing edge outlet direction.

[0060] That is, in actual processing, the buffer portion 13 can be formed by chamfering the outlet trailing edge of the working surface of the main body 1, or it can be integrally processed during the production of the main body 1, which is not limited here.

[0061] The setting of the buffer part 13 can reduce the secondary flow and separation loss at the outlet of the impeller 2, improve the working efficiency of the impeller 2, and at the same time reduce the trail loss of the blade trailing edge, reduce the dynamic and static interference between the impeller 2 and the static parts behind it, and reduce the airflow pressure pulsation.

[0062] Please refer to Figure 4 In some optional embodiments, the buffer portion 13 is a notch 14 formed at the outlet trailing edge of the working surface 11 of the main body 1 .

[0063] That is, the two aforementioned embodiments do not penetrate the working surface 11 and the non-working surface 12 , while this embodiment has a notch 14 at the outlet trailing edge of the working surface 11 , and the notch 14 penetrates the working surface 11 and the non-working surface 12 .

[0064] In one embodiment, the cross-section of the notch 14 can be in the shape of a triangle, a rectangle, a polygon, etc., which is not limited here.

[0065] The setting of the notch 14 is similar to the rounded corner and the chamfered corner mentioned above, both of which can reduce the separation loss and secondary flow loss at the outlet of the impeller 2, thereby achieving the purpose of improving efficiency and reducing noise.

[0066] In summary, in the compressor blade of the present invention, a buffer portion 13 is provided at the outlet trailing edge of the working surface 11 of the main body 1 in the direction toward the non-working surface 12, thereby reducing the normal momentum between the working surface 11 and the non-working surface 12, thereby reducing the secondary flow loss and separation loss at the outlet position of the impeller 2, and improving the working efficiency of the impeller 2.

[0067] At the same time, it can also reduce the trail loss of the blade trailing edge, reduce the dynamic and static interference between the impeller 2 and the static parts behind it, and reduce the airflow pressure pulsation.

[0068] The compressor impeller and high-temperature and high-pressure steam compressor proposed in the present invention include the above-mentioned compressor blades, so they also have the beneficial effects of the compressor blades, which will not be elaborated here.

[0069] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "install", "connect", "connect", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0070] The present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0071] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0072] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A compressor blade, characterized in that: include: The body has a working surface and a non-working surface arranged oppositely. The body is provided with a buffer portion at the outlet trailing edge of the working surface in the direction toward the non-working surface to reduce the secondary flow loss and separation loss at the outlet of the body trailing edge.

2. The compressor blade according to claim 1, characterized in that The buffer portion is arc-shaped at the outer edge of the outlet trailing edge of the body.

3. The compressor blade according to claim 2, characterized in that The thickness of the buffer portion decreases gradually along the direction from the center position of the body to the outlet trailing edge.

4. The compressor blade according to claim 2, characterized in that The size range of the buffer portion is: 1 / 80D2 to 1 / 40D2; wherein D2 is the outer diameter of the impeller corresponding to the body.

5. The compressor blade according to claim 1, characterized in that The buffer portion is plane at the outlet trailing edge of the working surface.

6. The compressor blade according to claim 5, characterized in that The thickness of the buffer portion decreases gradually along the direction from the center position of the body to the outlet trailing edge.

7. The compressor blade according to claim 1, characterized in that The buffer portion is a notch formed on the main body at the outlet trailing edge of the working surface.

8. The compressor blade according to claim 7, characterized in that The notch passes through the working surface and the non-working surface.

9. A compressor impeller, characterized in that: include: Roulette; wheel covers; A plurality of compressor blades according to any one of claims 1 to 8, wherein the plurality of compressor blades are located between the wheel disc and the wheel cover and are respectively connected to the wheel disc and the wheel cover.

10. The compressor impeller according to claim 9, characterized in that Some or all of the plurality of compressor blades are provided with a buffer portion at the outlet trailing edge of the working surface.

11. A high-temperature and high-pressure steam compressor, characterized in that: Comprising at least one compressor impeller according to any one of claims 9-10.

12. The high-temperature and high-pressure steam compressor according to claim 11, characterized in that: The number of the compressor impellers is at least six, and the steam temperature obtained by compression by the six compressor impellers is at least 530° C. and the steam pressure is at least 11.5 MPa.

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