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

Abstract

The invention provides a centrifugal compressor blade, an impeller and a high-temperature and high-pressure steam compressor, the centrifugal compressor blade comprises a body, the body is provided with a working face and a non-working face, and the body is provided with at least one circulation groove in the direction, facing the non-working face, of the outlet tail edge of the working face; the circulating groove penetrates through the working surface and the non-working surface; the invention further provides a centrifugal compressor impeller which comprises the centrifugal compressor blade. According to the centrifugal compressor blade, at least one circulating groove is formed in the outlet tail edge of the working face of the body in the direction facing the non-working face, so that secondary flow loss and separation loss at the outlet position of an impeller are reduced, efficiency is improved, and noise is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal compressors, and in particular to a centrifugal 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 centrifugal 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 centrifugal 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 centrifugal compressor blade, which is characterized by comprising:

[0008] The body has a working surface and a non-working surface, and the body is provided with at least one flow groove at the outlet trailing edge of the working surface in the direction toward the non-working surface; wherein,

[0009] The flow groove passes through the working surface and the non-working surface.

[0010] According to one embodiment of the present invention, the cross-sectional size of the flow groove increases gradually along the direction from the middle of the body to the outlet trailing edge.

[0011] According to an embodiment of the present invention, the circulation groove is triangular in shape along the projection direction from the working surface to the non-working surface.

[0012] According to an embodiment of the present invention, the cross-section of the flow groove in the width direction of the body is triangular.

[0013] According to one embodiment of the present invention, the flow groove is arranged in the middle of the outlet trailing edge region of the body.

[0014] According to one embodiment of the present invention, the number of the flow slot is one.

[0015] According to one embodiment of the present invention, the number of the circulation slots is multiple;

[0016] The plurality of flow grooves are arranged at intervals along the height direction of the outlet trailing edge of the body.

[0017] The present invention also provides a centrifugal compressor impeller, which is characterized in that it includes:

[0018] Roulette;

[0019] wheel covers;

[0020] A plurality of centrifugal compressor blades as described above are arranged between the wheel disc and the wheel cover and are respectively connected to the wheel disc and the wheel cover.

[0021] According to one embodiment of the present invention, a plurality of centrifugal compressor blades are evenly spaced along the outer circumference of the wheel disc.

[0022] According to one embodiment of the present invention, part or all of the plurality of centrifugal compressor blades are provided with at least one flow groove at the outlet trailing edge of the working surface.

[0023] The present invention also provides a high-temperature and high-pressure steam compressor, which is characterized in that it includes at least one centrifugal compressor impeller as described above.

[0024] According to one embodiment of the present invention, the number of the centrifugal compressor impellers is at least six, and the steam temperature obtained by compression by the six centrifugal compressor impellers is at least 530° C. and the steam pressure is at least 11.5 MPa.

[0025] The positive and progressive effects of the present invention are:

[0026] The centrifugal compressor blade of the present invention has a body with at least one flow groove at the outlet trailing edge of the working surface in the direction toward the non-working surface, thereby reducing secondary flow loss and separation loss at the impeller outlet position, thereby improving efficiency and reducing noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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:

[0028] Figure 1 It is a structural schematic diagram of the centrifugal compressor impeller of the present invention;

[0029] Figure 2 It is a schematic diagram of the matching structure of the centrifugal compressor blade and the impeller of the present invention;

[0030] Figure 3This is a simplified structural diagram of one embodiment of the flow channel of the present invention.

[0031] 1. Main body; 11. Working surface; 12. Non-working surface; 13. Flow slot;

[0032] 2. Impeller; 21. Disc; 22. Wheel cover. 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 flows to the impeller outlet under the action of the rotating centrifugal force and is subjected to the expansion effect of the impeller. 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 level impeller through the bend and the return device for further compression, so that the pressure and speed of the gas increase so that the gas pressure reaches the working pressure required by the process.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] Please refer to Figures 1 to 3 The present invention proposes a new centrifugal compressor impeller 2 without changing the overall structure of the impeller 2 and the blades. The centrifugal compressor impeller 2 includes a wheel disc 21, a wheel cover 22 and a plurality of centrifugal compressor blades. The plurality of centrifugal compressor blades are arranged between the wheel disc 21 and the wheel cover 22 and are respectively connected to the wheel disc 21 and the wheel cover 22.

[0040] It can be seen that multiple centrifugal compressor blades are evenly spaced along the outer circumference of the impeller 21. During the operation of the compressor, vortices are easily generated at the outlet of the centrifugal compressor blades and near the wheel cover 22, 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.

[0041] The present invention also provides a high-temperature and high-pressure steam compressor, comprising at least one centrifugal compressor impeller as described above.

[0042] Specifically, in order to meet the predetermined high-temperature and high-pressure steam outlet parameters, the number of centrifugal 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.

[0043] 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.

[0044] 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.

[0045] It can be seen that the steam parameters required by the chemical industry are relatively high, generally steam pressure 11.5MPa, steam temperature 530°C. The present invention can reuse the low-parameter steam generated by nuclear power plants through at least six-stage 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.

[0046] Please refer to Figure 2The centrifugal compressor blade of the present invention comprises a body 1, wherein the body 1 has a working surface 11 and a non-working surface 12, and the body 1 is provided with at least one flow groove 13 at the outlet trailing edge of the working surface 11 in the direction toward the non-working surface 12. The flow groove 13 penetrates the working surface 11 and the non-working surface 12.

[0047] It should be noted that the impeller 21 of the impeller 2 is evenly provided with a plurality of blades in the circumferential direction, and each of the plurality of blades may be provided with a flow groove 13 at the outlet trailing edge, or the flow groove 13 may be provided at the outlet trailing edge of some blades, which is not limited here. For the convenience of processing and assembly, the present invention provides the flow groove 13 at the outlet trailing edge of all blades, thereby improving the compression efficiency of the impeller 2.

[0048] That is, a plurality of centrifugal compressor blades are arranged between the wheel disc 21 and the wheel cover 22 , and a part or all of the plurality of centrifugal compressor blades are provided with flow grooves 13 at the outlet trailing edge of the working surface 11 .

[0049] The present invention sets a flow groove 13 at the outlet of the centrifugal compressor blade, 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. In this way, it can also meet the use under high temperature and high pressure conditions without changing the blade material.

[0050] In one embodiment, the cross-sectional size of the flow groove 13 increases gradually along the direction from the middle of the body 1 to the outlet trailing edge.

[0051] That is, the size of the circulation groove 13 increases gradually along the direction away from the middle of the body 1. Specifically, the circulation groove 13 is triangular in the projection direction from the working surface 11 to the non-working surface 12.

[0052] Under high temperature and high pressure conditions, a vortex is easily formed at the outlet trailing edge of the body 1, and the position of the vortex is closer to the trailing edge. If a larger hole is opened at the trailing edge, it is not conducive to the structural strength of the body 1, and a flow groove with a variable cross section is arranged along the trailing edge direction to gradually eliminate the vortex. In this way, without affecting the structural rigidity of the centrifugal compressor blade itself, the secondary flow vortex formed at the outlet trailing edge of the centrifugal compressor blade can be gradually destroyed along the flow direction of the secondary flow, thereby reducing the secondary flow loss and separation loss at the outlet trailing edge, so as to achieve the purpose of improving efficiency and reducing noise.

[0053] Please refer to Figure 3 In another embodiment, the cross-sectional shape of the flow groove 13 along the width direction of the body 1 is triangular.

[0054] Specifically, refer to Figure 2 , Figure 2 The X direction is the length direction of the blade, and extends along the axial direction close to the wheel disc 21. Figure 2 The Y direction in is the height direction of the blade, and Figure 2 The Z direction is the width direction of the blade.

[0055] 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 "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 devices or elements 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.

[0056] On the basis of the flow groove 13, the gas flow direction from the working surface 11 to the non-working surface 12 is guided, which is more conducive to destroying the vortex formed at the outlet trailing edge of the centrifugal compressor blade, thereby reducing the secondary flow loss and separation loss at the outlet trailing edge.

[0057] That is, the unit volume of the flow groove 13 from the side close to the working surface 11 to the flow groove 13 close to the non-working surface 12 gradually decreases, and then the airflow is guided according to the pressure difference between the working surface 11 and the non-working surface 12, which is more conducive to destroying the secondary flow loss and separation loss at the trailing edge of the outlet.

[0058] In one embodiment, the flow groove 13 is disposed in the middle of the outlet trailing edge region of the body 1 .

[0059] Setting the flow groove 13 in the middle of the outlet trailing edge area of ​​the main body 1 can maximize the elimination of the vortex formed in the trailing edge outlet area of ​​the main body 1, and can make the force load on the outlet trailing edge of the main body 1 more uniform when the compressor is in operation, thereby avoiding affecting the operating stability of the blade after the flow groove 13 is opened on the blade.

[0060] At this time, the number of the flow groove 13 is one, and the corresponding flow area of ​​the groove is larger, which is beneficial to reducing the separation loss and secondary flow loss at the outlet position of the impeller 2.

[0061] In some other embodiments, the number of the flow grooves 13 may also be multiple, and the multiple flow grooves 13 are arranged at intervals along the height direction of the outlet trailing edge of the body 1.

[0062] That is, the outlet trailing edge of the centrifugal compressor blade is multi-toothed, which helps to reduce the separation loss and secondary flow loss at the outlet of the impeller 2 while also ensuring the structural strength of the centrifugal compressor blade. The number of flow slots 13 on a specific single blade can be adjusted according to the actual operating state of the compressor and is not limited here.

[0063] In summary, the centrifugal compressor blade of the present invention has a body 1 that is provided with at least one flow groove 13 at the outlet trailing edge of the working surface 11 in the direction toward the non-working surface 12, thereby reducing the secondary flow loss and separation loss at the outlet of the impeller 2, thereby improving efficiency and reducing noise.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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 centrifugal compressor blade, characterized in that: include: The body has a working surface and a non-working surface, and the body is provided with at least one flow groove at the outlet trailing edge of the working surface in the direction toward the non-working surface; wherein, The flow groove passes through the working surface and the non-working surface.

2. The centrifugal compressor blade according to claim 1, characterized in that: The cross-sectional size of the flow groove increases gradually along the direction from the middle of the body to the outlet trailing edge.

3. The centrifugal compressor blade according to claim 2, characterized in that: The circulation groove is triangular in shape along the projection direction from the working surface to the non-working surface.

4. The centrifugal compressor blade according to claim 2, characterized in that: The cross-sectional shape of the flow channel in the width direction of the body is triangular.

5. The centrifugal compressor blade according to claim 1, characterized in that: The flow groove is arranged in the middle of the outlet trailing edge region of the body.

6. The centrifugal compressor blade according to claim 5, characterized in that: The number of the circulation slot is one.

7. The centrifugal compressor blade according to claim 5, characterized in that: The number of the circulation slots is multiple; The plurality of flow grooves are arranged at intervals along the height direction of the outlet trailing edge of the body.

8. A centrifugal compressor impeller, characterized in that: include: Roulette; wheel covers; A plurality of centrifugal compressor blades according to any one of claims 1 to 7, wherein the centrifugal compressor blades are arranged between the wheel disc and the wheel cover and are connected to the wheel disc and the wheel cover respectively.

9. The centrifugal compressor impeller according to claim 8, characterized in that: The plurality of centrifugal compressor blades are evenly spaced along the outer circumference of the wheel disc.

10. The centrifugal compressor impeller according to claim 8, characterized in that: Part or all of the plurality of centrifugal compressor blades are provided with at least one flow groove 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 centrifugal compressor impeller according to any one of claims 8-10.

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

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