Centrifugal compressor casing adapting to ultrahigh pressure ratio and centrifugal compressor with centrifugal compressor casing

Abstract

The invention discloses a centrifugal compressor casing adapting to ultrahigh pressure ratio and a centrifugal compressor with the centrifugal compressor casing. The centrifugal compressor casing comprises a casing integration body integrally designed by integrating an existing air inlet casing, an adapter casing, an impeller outer cover and a diffuser casing, and a plurality of inlet guide vanes integrally designed with the casing integration body, the multiple inlet guide vanes are sequentially connected to the inner wall face of an air inlet flow channel in the casing integration body at intervals in the circumferential direction of the casing integration body. A plurality of gas circulation channels which are sequentially arranged at intervals in the circumferential direction are further arranged in the inner wall face of the gas inlet flow channel and extend in the gas inlet axial direction, and the two ends of each gas circulation channel penetrate through the inner wall face of the case integration body to communicate with the gas inlet flow channel so as to form a gas self-circulation structure. According to the structure, integration of stator parts of the gas compressor is achieved to the maximum extent, meanwhile, the stability of inlet airflow in the working state can be improved to the maximum extent, the structure is simple, the working stability is high, the stable working margin of the gas compressor can be effectively improved, and surge is prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of compressor casings, and in particular, to a centrifugal compressor casing adapted to ultra-high pressure ratios. In addition, the present invention also relates to a centrifugal compressor comprising the centrifugal compressor casing adapted to ultra-high pressure ratios. Background Art

[0002] The structure of ultra-high pressure ratio (generally single-stage centrifugal pressure ratio of 15, temperature rise above 400°C) centrifugal compressor is generally designed according to the traditional structure. The stator parts usually include an intake casing (forming an inlet duct), a transfer casing (transferring the impeller cover and the intake casing, installing inlet guide vanes), inlet guide vanes (inlet air flow guide), an impeller cover (forming the corresponding flow channel of the centrifugal impeller), a diffuser casing (installing radial diffusers and axial diffusers), a diffuser structure (usually including radial and axial diffuser blades, cover plates and other structures), etc.

[0003] Ultra-high pressure ratio compressors need to adopt stabilization measures to ensure their stable operating margin and prevent surge. This is usually achieved by using adjustable inlet guide vanes (which require a guide vane adjustment system) or intermediate bleed (which requires a bleed stabilization system), and is generally indispensable.

[0004] In the prior art, ultra-high pressure ratio centrifugal compressors have a relatively large pressure ratio and a greatly increased temperature gradient, and have high comprehensive design requirements for single functional components such as strength, stiffness, and thermal deformation. Therefore, in the prior art, when designing the compressor casing, multiple parts are generally used to ensure them separately, resulting in a large number of parts for the ultra-high pressure ratio centrifugal compressor stator, heavy weight, and high processing costs; the compressor assembly and disassembly process is relatively complicated, and the assembly and maintenance costs are high; in order to meet the needs of the ultra-high pressure ratio, a guide vane adjustment system or an air bleed expansion system is required, which requires additional weight, and at the same time increases the processing and assembly costs of accessories and pipelines. At the same time, the problem of insufficient margin for stable operation caused by the greatly increased pressure ratio also needs to be solved by a supporting system; the inlet and outlet of the impeller cover are continuous, and the inlet deformation and clearance control are difficult. Summary of the invention

[0005] The present invention provides a centrifugal compressor casing adaptable to ultra-high pressure ratio and a centrifugal compressor having the same, so as to solve the technical problems of the existing centrifugal compressor structure having a large number of parts, heavy weight, high processing cost, additional weight, and increased processing and assembly costs of accessories and pipelines.

[0006] The technical solution adopted by the present invention is as follows: A centrifugal compressor casing adapted to an ultra-high pressure ratio comprises: an integrated casing body integrated with an existing air intake casing, a transfer casing, an impeller cover and a diffuser casing, and a plurality of inlet guide vanes integrated with the integrated casing body, wherein the plurality of inlet guide vanes are connected to the inner wall surface of an air intake passage in the integrated casing body in sequence and at intervals along the circumference of the integrated casing body; the inner wall surface of the air intake passage of the integrated casing body is also provided with a plurality of gas circulation passages arranged in sequence and at intervals along the circumference, the plurality of gas circulation passages extend along the air intake axis, and the two ends of each gas circulation passage respectively penetrate the inner wall surface of the integrated casing body to connect the air intake passage and thereby form a gas self-circulation structure.

[0007] Furthermore, an inwardly concave annular air collecting chamber is provided on the inner wall surface of the inlet air duct, the air collecting chamber is close to the impeller tip of the centrifugal impeller installed in the inlet air duct, and the air collecting chamber is connected to the air inlet end of the gas circulation channel to form an air inlet, and the air outlet end of the gas circulation channel extends to the air inlet port close to the inlet air duct.

[0008] Furthermore, the width of the gas collecting cavity along the axial direction is 1 mm to 2 mm; the width of the gas outlet at the gas outlet end of the gas circulation channel along the radial direction is 2 mm to 3 mm.

[0009] Furthermore, the integrated casing body includes a hollow cylindrical casing body and an internal flow channel ring, and a plurality of internal ribs that serve as a connection; the internal flow channel ring is located in the casing body, and the plurality of internal ribs are arranged in sequence along the circumferential direction and connected between the inner wall surface of the casing body and the outer wall surface of the internal flow channel ring, so that a plurality of gas circulation channels arranged in sequence along the circumferential direction are formed between the inner wall surface of the casing body and the outer wall surface of the internal flow channel ring; the inner channel of the internal flow channel ring forms an inlet flow channel, and a plurality of inlet guide vanes are connected to the inner wall surface of the internal flow channel ring in sequence along the circumferential direction.

[0010] Furthermore, the inner wall surface of the casing body is concave to form an air collecting chamber; the internal flow channel ring and the internal rib plate are flush with each other near the first end of the air collecting chamber, and the first ends of the two form the outer wall of the air collecting chamber; the second end of the internal rib plate extends to the air inlet port near the casing body, and the second end of the internal flow channel ring extends axially near the second end of the internal rib plate to form an outlet of the gas circulation channel between the two.

[0011] Furthermore, the thickness of the internal ribs is 2 mm to 4 mm; the thicknesses of multiple internal ribs are exactly the same or the thicknesses of some internal ribs are different, the thickness of each internal rib along its length direction remains unchanged or changes according to specific support strength and stiffness requirements; the height of the internal ribs changes adaptively with the height of the gas circulation channel.

[0012] Furthermore, the casing body includes connecting plates at both ends thereof, an intake section whose one end is connected to the connecting plate at the intake end and extends axially in a cylindrical shape to cooperate with the internal flow channel ring, a first flared section connected to the intake section and in a flared shape, a connecting section radially connected to the flared end of the first flared section, a second flared section connected to the connecting section and in an axially flared shape, and the flared end of the second flared section is connected to the connecting plate at the outlet end; the connecting section and the second flared section are used to cooperate and connect to the diffuser casing, and form a first chamber and a second chamber for air introduction therebetween.

[0013] Furthermore, the integrated casing body also includes a plurality of external ribs connected to the connecting section, the first expansion section and the outer wall surface of the air intake section, and the plurality of external ribs are arranged in sequence and spaced apart along the circumferential direction.

[0014] Furthermore, the thickness of the external ribs is 2 mm to 4 mm; the thicknesses of multiple external ribs are the same or the thicknesses of some of the external ribs are different, the lengths of each external rib along its length direction are different according to the strength and stiffness requirements of its setting position, and the thicknesses of each external rib along its length direction are also different according to the strength and stiffness requirements of its setting position.

[0015] According to another aspect of the present invention, there is provided a centrifugal compressor, comprising a centrifugal compressor casing adapted to an ultra-high pressure ratio as described above, and an integrally formed one-piece diffuser; the compressor casing and the one-piece diffuser are connected axially.

[0016] The present invention has the following beneficial effects: The scheme of the present invention relates to a compressor casing structure suitable for an ultra-high pressure ratio compressor. In the compressor casing structure, an air intake casing, a transfer casing, an impeller cover and a diffuser casing of a traditional structure are integrated into a casing integrated body. If an integrated diffuser is provided, the compressor part only includes two stators. The structure realizes the integration of the compressor stator parts to the greatest extent, ensures the extremely high economy of the stator parts, and simplifies the structure to the greatest extent, with a small number of parts, low processing, assembly and maintenance costs, and a significant reduction in weight. During assembly, only the minimum assembly process requirements of the centrifugal impeller need to be met, and the assembly is simple and the assembly precision is high. On the other hand, compared with the prior art, the structure of the present invention is simplified to the greatest extent and the low-cost design eliminates the adjustable guide vane structure and the venting chamber structure in the prior art that can expand the stable working range. The present invention adopts improvement measures that are compatible with the ultra-high pressure ratio performance, such as Figure 2 and Figure 6As shown, the adjustable guide vane structure is simplified to a targeted integral guide vane integrated on the casing integrated body, i.e., the inlet guide vane, which is integrated with the casing integrated body into one part and does not need to be installed separately, so that the inlet guide vane remains fixed to maximize the stability of the inlet airflow in the working state; at the same time, a plurality of gas circulation channels arranged at circumferential intervals are arranged on the inner wall surface of the inlet airflow channel, and the gas generated when the centrifugal impeller is working in the intermediate state or transition state can first enter the gas circulation channel, and then be discharged into the inlet airflow channel from the outlet end of the gas circulation channel to form a self-circulation structure, which reduces gas loss on the one hand, and improves the stable working range without intermediate venting compared with the existing structure, so it has a simple structure and high working stability, which can effectively improve the stable working margin of the compressor and prevent surge, and on the other hand, the gas circulation channel is processed in an integrated manner, the molding process is simple, and the effect of improving the stability margin of the ultra-high pressure ratio compressor can be achieved by increasing a small amount of mass, and compared with the traditional structure of improving the stability margin by collecting and venting gas, the structure is simpler, and the cost of multiple parts and accessories such as venting valves can be saved, and the benefit-cost ratio is extremely high.

[0017] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is a schematic diagram of the main structure of a centrifugal compressor according to a preferred embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of the main structure of a centrifugal compressor casing adapted to an ultra-high pressure ratio; Figure 3 yes Figure 2 Schematic diagram of the size design of the gas circulation channel; Figure 4 yes Figure 3 AA-direction cross-sectional structural diagram; Figure 5 yes Figure 3 Schematic diagram of the cross-sectional structure in the middle BB direction; Figure 6 It is a schematic diagram of a half-section structure of a centrifugal compressor according to a preferred embodiment of the present invention.

[0019] Legend: 1. Casing integrated body; 101. Inlet flow channel; 102. Gas circulation channel; 103. Gas collecting cavity; 104. First chamber; 105. Second chamber; 11. Casing body; 111. Inlet section; 112. First expansion section; 113. Connecting section; 114. Second expansion section; 12. Internal flow channel ring; 13. Internal rib plate; 14. External rib plate; 2. Inlet guide vane; 3. Centrifugal impeller; 4. Integrated diffuser. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0021] Reference Figure 2 and Figure 6 The preferred embodiment of the present invention provides a centrifugal compressor casing adapted to an ultra-high pressure ratio, comprising: a casing integrated body 1 integrated with an existing air intake casing, a transfer casing, an impeller cover and a diffuser casing, and a plurality of inlet guide vanes 2 integrated with the casing integrated body 1, wherein the plurality of inlet guide vanes 2 are sequentially connected to the inner wall surface of an inlet flow passage 101 in the casing integrated body 1 at intervals along the circumference of the casing integrated body 1. A plurality of gas circulation passages 102 are also provided in the inner wall surface of the inlet flow passage 101 of the casing integrated body 1 at intervals along the circumference, and the plurality of gas circulation passages 102 extend along the inlet axial direction, and the two ends of each gas circulation passage 102 respectively penetrate the inner wall surface of the casing integrated body 1 to connect the inlet flow passage 101 and thus form a gas self-circulation structure.

[0022] The scheme of the present invention relates to a compressor casing structure suitable for an ultra-high pressure ratio compressor, in which the air intake casing, the transfer casing, the impeller cover and the diffuser casing of the traditional structure are integrated into a casing integrated body 1. If an integrated diffuser is provided, the stator parts of the compressor only include two. The structure realizes the integration of the compressor stator parts to the greatest extent, ensures the extremely high economy of the stator parts, and simplifies the structure to the greatest extent, with a small number of parts, low processing, assembly and maintenance costs, and a significant reduction in weight. During assembly, only the minimum assembly process requirements of the centrifugal impeller need to be met, and the assembly is simple and the assembly precision is high. On the other hand, compared with the prior art, the structure of the present invention is simplified to the greatest extent and the low-cost design eliminates the adjustable guide vane structure and the venting chamber structure in the prior art that can expand the stable working range. The present invention adopts improvement measures that are compatible with the ultra-high pressure ratio performance, such as Figure 2 and Figure 6As shown, the adjustable guide vane structure is simplified to a specifically designed integral guide vane integrated on the casing integrated body 1, namely, the inlet guide vane 2, which is integrated into one part with the casing integrated body 1 and does not need to be installed separately, so that the inlet guide vane 2 can be kept fixed to maximize the stability of the inlet airflow in the working state; at the same time, a plurality of gas circulation channels 102 arranged at intervals in the circumferential direction are provided on the inner wall surface of the inlet airflow channel 101, and the gas generated when the centrifugal impeller is working in the intermediate state or the transition state can first enter the gas circulation channel 102, and then be discharged into the inlet airflow from the outlet end of the gas circulation channel 102 Channel 101 forms a self-circulating structure, which can reduce gas loss on the one hand. Compared with the existing structure, it can improve the stable working range without intermediate bleed, so it has a simple structure and high working stability, which can effectively improve the stable working margin of the compressor and prevent surge. On the other hand, the gas circulation channel 102 is processed in one piece, and the molding process is simple. The effect of improving the stability margin of the ultra-high pressure ratio compressor can be achieved by adding a small amount of mass. Compared with the traditional structure that improves the stability margin by collecting and bleed air, this structure is simpler, can save the cost of multiple parts and accessories such as bleed valves, and has a very high benefit-cost ratio.

[0023] Alternatively, if Figure 2 As shown, a concave annular gas collecting chamber 103 is also provided on the inner wall surface of the inlet flow channel 101. The gas collecting chamber 103 is close to the impeller tip of the centrifugal impeller 3 installed in the inlet flow channel 101, and the gas collecting chamber 103 is connected to the inlet end of the gas circulation channel 102 to form an inlet port. The outlet end of the gas circulation channel 102 extends to the inlet port close to the inlet flow channel 101. During operation, the gas generated by the centrifugal impeller in the intermediate state or transition state first enters the gas collecting chamber 103 for gas collection, then enters the gas circulation channel 102, and finally enters the inlet flow channel 101 from the inlet end of the inlet flow channel 101, forming a self-circulating structure, which can improve the stable working range of the compressor without intermediate venting, and does not need to set a venting chamber and a venting valve, which also makes the overall structure simple.

[0024] Preferably, if Figure 3 As shown, the axial width of the gas collecting cavity 103 is 1 mm to 2 mm. The radial width of the gas outlet at the outlet end of the gas circulation channel 102 is 2 mm to 3 mm. In this preferred embodiment, by adjusting the parameters of the gas collecting cavity 103 and the gas circulation channel 102, such as the inlet width s1 and the outlet width s2, the effect of improving the stable working range of the self-circulation can be controlled.

[0025] In this option, if Figure 2 and Figure 6As shown, the casing integrated body 1 includes a hollow cylindrical casing body 11 and an internal flow channel ring 12, and a plurality of internal ribs 13 that serve as a connection. The internal flow channel ring 12 is located inside the casing body 11, and a plurality of internal ribs 13 are sequentially spaced along the circumferential direction and connected between the inner wall surface of the casing body 11 and the outer wall surface of the internal flow channel ring 12, so that a plurality of gas circulation channels 102 sequentially spaced along the circumferential direction are formed between the inner wall surface of the casing body 11 and the outer wall surface of the internal flow channel ring 12. The inner channel of the internal flow channel ring 12 forms an inlet flow channel 101, and a plurality of inlet guide vanes 2 are sequentially spaced along the circumferential direction and connected to the inner wall surface of the internal flow channel ring 12. The airflow channel formed by the casing body and the internal flow channel ring is used to stabilize the structure of the ultra-high pressure ratio centrifugal compressor.

[0026] In the present invention, multiple parts are highly integrated into an integrated casing body 1. In addition to ensuring the stability of the work, the strength and deformation coordination of the parts under ultra-high temperature gradients are themselves difficult to design. In addition, the need to integrate them into an integrated casing body 1 greatly increases the design difficulty. In the structure of the present invention, the internal flow channel ring 12 is connected to the inner wall surface of the casing body 11 through the internal rib plate 13, and constitutes a partial flow channel, namely the gas circulation channel 102. On the one hand, it can reduce the stress in the high temperature gradient area, and at the same time, it forms a partial isolation with the high temperature area of ​​the casing body 11 that is only connected to the internal rib plate 13 (due to gas compression, the closer to the diffuser part, the higher the temperature), which is conducive to controlling the thermal deformation of the inlet flow channel 101, thereby better controlling the radial working clearance between the centrifugal impeller and the outer cover inlet (due to the high sensitivity of the hot clearance at this position to the compressor performance); on the other hand, the gas collecting cavity 103 and the gas circulation channel 102 are connected to the casing body 11. It is divided into multiple parts, among which the casing body 11 can also ensure the overall strength and adjust the stiffness of the casing integrated body 1 by adjusting the wall thickness at its local position. At the same time, the internal rib plate 13 can also achieve the purpose of ensuring the strength and adjusting the stiffness of the casing integrated body 1 by adjusting the specific structural parameters. Therefore, in the structure of the present invention, the stiffness adjustment and the independent internal flow channel ring 12 structure are specifically adopted to ensure the coordination of its strength and thermal deformation under high temperature gradient, and the internal stabilization structure is adopted to ensure the stability of its working performance. In addition, by adjusting the wall thickness and the rib plate thickness, a parametric structure with strength meeting the design requirements, flow channel deformation matching the optimal aerodynamic performance, and overall lighter weight can be obtained.

[0027] In this option, if Figure 2As shown, the inner wall surface of the casing body 11 is concave to form a gas collecting chamber 103. The first ends of the internal flow channel ring 12 and the internal rib plate 13 close to the gas collecting chamber 103 are flush, and the first ends of the two form the outer side wall of the gas collecting chamber 103. The second end of the internal rib plate 13 extends to the air inlet port close to the casing body 11, and the second end of the internal flow channel ring 12 extends axially close to the second end of the internal rib plate 13 to form the outlet of the gas circulation channel 102 between the two.

[0028] In this option, if Figure 3-4 As shown, the thickness of the internal rib plate 13 is 2 mm to 4 mm. Under this size, the required thermal deformation effect of the flow path surface and lighter weight can be obtained. The thicknesses of multiple internal rib plates 13 are exactly the same or the thicknesses of some internal rib plates 13 are different. The thickness of each internal rib plate 13 along its length direction remains unchanged or changes according to specific support strength and stiffness requirements. The height of the internal rib plate 13 changes adaptively with the height of the gas circulation channel 102. During design, the gas collecting cavity 103 and the gas circulation channel 102 divide the casing body 11 into multiple parts, among which the casing body 11 can ensure the strength and adjust the stiffness of the casing integrated body 1 by adjusting the wall thickness at a local position, and the internal rib plate 13 can also achieve the purpose of ensuring the strength and adjusting the stiffness of the casing integrated body 1 by adjusting the specific structural parameters (such as Figure 3-4 As shown, the height and thickness h1 and t1 of the internal ribs 13, the wall thickness t at different positions of the casing body 11, and the number of the internal ribs 13 are adjusted. The thicker the wall thickness at different positions of the casing body 11, the stronger the rigidity, and the thicker the internal ribs 13, the stronger the rigidity. At the same time, the internal ribs 13 can also strengthen the strength of the weak position. When setting, the position parameters are adjusted and determined during the design process according to the working conditions. After the design is completed, the strength and rigidity are determined immediately, and the range of the structural parameters is obtained through multidisciplinary iterative optimization, which can achieve a more coordinated flow path surface thermal deformation effect and a better effect of improving the stable working margin of the compressor.

[0029] Alternatively, if Figure 2-3 As shown, the casing body 11 includes connecting plates at both ends thereof, an inlet section 111 whose one end is connected to the connecting plate at the inlet end and extends axially in a cylindrical shape to cooperate with the internal flow channel ring 12, a first flared section 112 connected to the inlet section 111 and in a flared shape, a connecting section 113 connected radially to the flared end of the first flared section 112, a second flared section 114 connected to the connecting section 113 and in an axial flared shape, and the flared end of the second flared section 114 is connected to the connecting plate at the outlet end. The connecting section 113 and the second flared section 114 are used to cooperate with the diffuser housing, and form a first chamber 104 and a second chamber 105 for bleed air therebetween. Compared with the traditional structure, this position structure setting can ensure that the original bleed air function is basically retained while the total mass is reduced.

[0030] Furthermore, if Figure 2 As shown, the casing integrated body 1 also includes a plurality of external ribs 14 connected to the connecting section 113, the first expansion section 112 and the outer wall surface of the air intake section 111, and the plurality of external ribs 14 are sequentially arranged at intervals along the circumferential direction. In actual design, in addition to ensuring the strength and adjusting the rigidity of the casing integrated body 1 by adjusting the wall thickness of a local position of the casing body 11, the external ribs 14 can also achieve the purpose of ensuring the strength and adjusting the rigidity of the casing integrated body 1 by adjusting specific structural parameters, such as Figure 5 As shown, the height and thickness h2, t2 of the external ribs 14 and the number of the external ribs 14 can be adjusted. The thicker and higher the external ribs 14 are, the stronger the rigidity is. At the same time, the external ribs 14 can also strengthen the strength of weak positions. According to the working conditions, the position parameters are adjusted and determined during the design process. After the design is completed, the strength and rigidity are immediately determined.

[0031] In this option, if Figure 3 and Figure 5 As shown, the thickness of the external rib plate 14 is 2 mm to 4 mm. Under this size, the required flow path surface thermal deformation effect and light weight can be obtained. The thickness of multiple external rib plates 14 is the same or the thickness of some external rib plates 14 is different. The length of each external rib plate 14 along its length direction is different according to the strength and rigidity requirements of its setting position, and the thickness of each external rib plate 14 along its length direction is also different according to the strength and rigidity requirements of its setting position.

[0032] During the design, under ultra-high temperature gradient, the strength and deformation coordination design of parts become design difficulties. In addition, the need to integrate into one part makes the design difficulty more greatly increased. The present invention aims at the integration of casing with ultra-high temperature gradient under ultra-high pressure ratio, and innovatively adopts a strength-enhanced, deformation-coordinated structure and an integrated double-layer structure (casing body 11 and internal flow channel ring 12) to overcome the problems caused by high temperature gradient, while the integrated processing cost is basically unchanged; at the same time, the gas circulation channel 102 formed by the internal rib plate 13, the casing body 11, and the internal flow channel ring 12 can form a self-circulating stabilization structure with ultra-high pressure ratio through design and optimization, so as to solve the problem of insufficient surge margin of ultra-high pressure ratio compressor.

[0033] Reference Figure 1The preferred embodiment of the present invention also provides a centrifugal compressor, including a centrifugal compressor casing adapted to an ultra-high pressure ratio as described above, and an integrally formed one-piece diffuser 4. The compressor casing is connected to the one-piece diffuser 4 along the axial direction. The centrifugal compressor of the present invention realizes the integration of the compressor stator parts to the greatest extent, ensures the extremely high economy of the stator parts, and simplifies the structure to the greatest extent, with a small number of parts, low processing, assembly and maintenance costs, and a significant reduction in weight. During assembly, it is only necessary to ensure the minimum assembly process requirements of the centrifugal impeller, and the assembly is simple and the assembly precision is high; on the other hand, the inlet guide vane 2 is integrated into one part with the casing integrated body 1, and does not need to be installed separately, so that the inlet guide vane 2 can be kept fixed to maximize the stability of the inlet airflow in the working state, and at the same time, a self-circulation structure can be formed to reduce gas loss. Compared with the existing structure, it does not need to bleed air in the middle to improve the stable working range, so it has a simple structure and high working stability, which can effectively improve the stable working margin of the compressor and prevent surge.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A centrifugal compressor casing adapted to ultra-high pressure ratio, characterized in that: include: An integrated casing body (1) integrated with an existing air intake casing, a transfer casing, an impeller cover and a diffuser casing, and a plurality of inlet guide vanes (2) integrated with the casing integrated body (1), wherein the plurality of inlet guide vanes (2) are connected to the inner wall surface of an inlet air flow passage (101) in the casing integrated body (1) in sequence and at intervals along the circumference of the casing integrated body (1); A plurality of gas circulation channels (102) are also provided in the inner wall surface of the inlet flow channel (101) of the casing integrated body (1) and are arranged in sequence and spaced apart in the circumferential direction. The plurality of gas circulation channels (102) extend along the inlet axis, and both ends of each gas circulation channel (102) respectively penetrate the inner wall surface of the casing integrated body (1) to connect with the inlet flow channel (101) to form a gas self-circulation structure.

2. The centrifugal compressor casing adapted to ultra-high pressure ratio according to claim 1, characterized in that: An annular concave gas collecting chamber (103) is also provided on the inner wall surface of the inlet flow channel (101), the gas collecting chamber (103) is close to the impeller tip of a centrifugal impeller (3) installed in the inlet flow channel (101), and the gas collecting chamber (103) is connected to the inlet end of the gas circulation channel (102) to form an inlet port, and the outlet end of the gas circulation channel (102) extends to the inlet port close to the inlet flow channel (101).

3. The centrifugal compressor casing adapted to ultra-high pressure ratio according to claim 2, characterized in that: The width of the gas collecting cavity (103) along the axial direction is 1 mm to 2 mm; the width of the gas outlet at the gas outlet end of the gas circulation channel (102) along the radial direction is 2 mm to 3 mm.

4. The centrifugal compressor casing adapted to ultra-high pressure ratio according to claim 2, characterized in that: The casing integrated body (1) comprises a hollow cylindrical casing body (11) and an internal flow channel ring (12), and a plurality of internal ribs (13) for connecting the casing body (11); the internal flow channel ring (12) is located inside the casing body (11); the plurality of internal ribs (13) are arranged in sequence at intervals along the circumferential direction and connected between the inner wall surface of the casing body (11) and the outer wall surface of the internal flow channel ring (12), so that a plurality of gas circulation channels (102) arranged in sequence at intervals along the circumferential direction are formed between the inner wall surface of the casing body (11) and the outer wall surface of the internal flow channel ring (12); the inner channel of the internal flow channel ring (12) forms an inlet flow channel (101), and a plurality of inlet guide vanes (2) are connected to the inner wall surface of the internal flow channel ring (12) in sequence at intervals along the circumferential direction.

5. The centrifugal compressor casing adapted to ultra-high pressure ratio according to claim 4, characterized in that: The inner wall surface of the casing body (11) is concave to form a gas collecting chamber (103); the first ends of the internal flow channel ring (12) and the internal rib plate (13) close to the gas collecting chamber (103) are flush, and the first ends of the two form the outer wall of the gas collecting chamber (103); the second end of the internal rib plate (13) extends to the gas inlet port close to the casing body (11), and the second end of the internal flow channel ring (12) extends axially close to the second end of the internal rib plate (13) to form an outlet of the gas circulation channel (102) between the two.

6. The centrifugal compressor casing adapted to ultra-high pressure ratio according to claim 4, characterized in that: The thickness of the internal rib plate (13) is 2 mm to 4 mm; the thicknesses of the plurality of internal rib plates (13) are completely the same or the thicknesses of some of the internal rib plates (13) are different; the thickness of each internal rib plate (13) along its length direction remains constant or varies according to specific support strength and rigidity requirements; the height of the internal rib plate (13) varies adaptively with the height of the gas circulation channel (102).

7. The centrifugal compressor casing adapted to ultra-high pressure ratio according to claim 4, characterized in that: The casing body (11) comprises connecting plates at both ends thereof, an inlet section (111) having one end connected to the connecting plate at the inlet end and extending axially in a cylindrical shape to cooperate with the internal flow channel ring (12), a first flared section (112) connected to the inlet section (111) and in a flared shape, a connecting section (113) connected radially to the flared end of the first flared section (112), a second flared section (114) connected to the connecting section (113) and in a flared shape in the axial direction, and the flared end of the second flared section (114) connected to the connecting plate at the outlet end; the connecting section (113) and the second flared section (114) are used to cooperate with and connect to the diffuser housing, and form a first chamber (104) and a second chamber (105) for bleed air therebetween.

8. The centrifugal compressor casing adapted to ultra-high pressure ratio according to claim 7, characterized in that: The integrated casing body (1) further comprises a plurality of external ribs (14) connected to the connecting section (113), the first expansion section (112) and the outer wall surface of the air intake section (111), wherein the plurality of external ribs (14) are arranged in sequence and spaced apart along the circumferential direction.

9. The centrifugal compressor casing adapted to ultra-high pressure ratio according to claim 8, characterized in that: The thickness of the external ribs (14) is 2 mm to 4 mm; the thickness of the plurality of external ribs (14) is the same or the thickness of some of the external ribs (14) is different; the length of each external rib (14) along its length direction is different according to the strength and rigidity requirements of its setting position, and the thickness of each external rib (14) along its length direction is also different according to the strength and rigidity requirements of its setting position.

10. A centrifugal compressor, characterized in that: It comprises a centrifugal compressor casing adapted to an ultra-high pressure ratio as described in any one of claims 1 to 9, and an integral diffuser (4) formed in one piece; the compressor casing and the integral diffuser (4) are connected axially.

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