A multi-stage centrifugal compressor rotor structure adapted to 600°C exhaust temperature

Abstract

A multi-stage centrifugal compressor rotor structure adapted to an exhaust temperature of 600°C relates to the technical field of compressors. In order to solve the problem that the impeller and the main shaft of the existing set rotor are easy to loosen at high temperatures, and cannot meet the requirements of safe and reliable operation of the compressor in the high-temperature heat storage technology route. The present invention includes a coupling section, a front support bearing section, a front shaft seal section, a centrifugal impeller section, a balance piston section, a rear shaft seal section, a rear support bearing section and a thrust bearing section. The air inlet end of the rotor is installed in the front bearing box through the front support bearing section, and the air outlet end of the rotor is installed in the rear bearing box through the rear support bearing section; the centrifugal impeller section includes a multi-stage impeller, and the adjacent two-stage impellers are connected by welding. A hollow cavity is provided on both sides of the axial center position of each stage of the impeller on the rotor main shaft; the air inlet end of the centrifugal impeller section is welded to the air outlet end of the front shaft seal section, and the air outlet end of the centrifugal impeller section is welded to the air inlet end of the balance piston section. The present invention is mainly used for centrifugal compressors.

Description

Technical Field

[0001] The invention relates to the technical field of compressors, and in particular to a multi-stage centrifugal compressor rotor structure adapted to an exhaust temperature of 600°C. Background Art

[0002] Under the strategy of "carbon peak and carbon neutrality", it is imperative to gradually build a new power system with new energy as the main body. New energy such as wind energy and solar energy are greatly affected by natural factors, and have obvious natural properties such as volatility, intermittency and reverse peak regulation, which poses a major challenge to the safe operation of the power system. Energy storage and new energy power generation, coordinated and optimized operation of the power system has become the only way to achieve the dual carbon goals.

[0003] Using heat pump cycles for high-temperature heat storage is an important technical route in the current energy storage field, and the compressor is the core factor that determines the success or failure of this technical route. The exhaust temperature of traditional multi-stage centrifugal compressors is below 400°C, and the impeller and the main shaft are assembled in a set. In the high-temperature heat storage technology route, the compressor exhaust temperature is close to 600°C, and the impeller and the main shaft are assembled in a set. At high temperatures, it is easy for the impeller and the main shaft to loosen. Therefore, the existing rotor form can no longer meet the requirements for safe and reliable operation of the compressor. It is necessary to develop a multi-stage centrifugal compressor rotor structure that can adapt to the exhaust temperature of 600°C. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the impeller and the main shaft of the existing set rotor are prone to loosening at high temperatures, and cannot meet the requirements for safe and reliable operation of the compressor in the high-temperature heat storage technology route; and thus provide a multi-stage centrifugal compressor rotor structure that can adapt to an exhaust temperature of 600°C.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A multi-stage centrifugal compressor rotor structure adapted to an exhaust temperature of 600°C comprises a coupling section, a front supporting bearing section, a front shaft seal section, a centrifugal impeller section, a balancing piston section, a rear shaft seal section, a rear supporting bearing section and a thrust bearing section which are axially integrated in sequence, wherein the air inlet end of the rotor is mounted in a front bearing box via the front supporting bearing section, and the air outlet end of the rotor is mounted in a rear bearing box via the rear supporting bearing section; the centrifugal impeller section comprises a plurality of impellers which are axially arranged in sequence, and two adjacent impellers are connected together by welding, and a hollow cavity is respectively arranged on both sides of the shaft sections at the axial center position of each impeller stage on the rotor main shaft; the air inlet end of the centrifugal impeller section is welded to the air outlet end of the front shaft seal section, and the air outlet end of the centrifugal impeller section is welded to the air inlet end of the balancing piston section.

[0007] Furthermore, each stage of the impeller includes an impeller shaft, a wheel disc, a plurality of moving blades and an annular cover plate, the impeller shaft is coaxially arranged with the wheel disc, and the two ends of the impeller shaft are respectively located on both sides of the wheel disc, the plurality of moving blades are evenly arranged circumferentially on one side of the wheel disc, and the wheel disc, the impeller shaft and the plurality of moving blades are integrally processed; the annular cover plate is welded to the plurality of moving blades, and a plurality of air passages are formed between the annular cover plate, the wheel disc and the plurality of moving blades; the two adjacent stages of impellers are welded together through the impeller shaft.

[0008] Furthermore, the end faces at both ends of the impeller shaft each have a coaxially arranged first groove, the end face of the outlet end of the front shaft seal section has a second groove, and the end face of the inlet end of the balance piston section has a third groove. The first groove at the inlet end of the first-stage impeller and the second groove of the front shaft seal section form a hollow cavity, the first groove between the two adjacent impellers forms a hollow cavity, and the first groove at the outlet end of the last-stage impeller and the third groove of the balance piston section form a hollow cavity.

[0009] Furthermore, the centrifugal impeller section includes a four-stage impeller. Along the air inlet direction of the rotor, the outer diameters of the four-stage impeller are 1430 mm, 1391 mm, 1296 mm and 1211 mm respectively.

[0010] Furthermore, the inlet hub diameters of the multiple moving blades of the four-stage impeller are equal, both being 480 mm.

[0011] Furthermore, the outer diameters of the impeller shafts of the four-stage impellers are equal, both being 429 mm.

[0012] Furthermore, the wall thickness of the rotor portion corresponding to the hollow cavity is 40 mm.

[0013] Furthermore, the journals of the front support bearing section and the rear support bearing section are 354.9 mm.

[0014] Furthermore, the rotor is made of steel of type x13CrMoCoVNbNB9-2-1.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] In the present invention, each level of impellers of the centrifugal impeller section is processed separately, and the shaft ends of different impellers and impellers and rotors are assembled by welding. The centrifugal impeller section and the main shaft of the rotor form an integrated structure, which ensures the safety and reliability of the shaft system of the multi-stage centrifugal compressor at an exhaust temperature of 600°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, as a part of this application, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute improper limitations on the present invention.

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 A schematic diagram of assembling the rotor of the present invention into a casing;

[0020] Figure 3 is a schematic diagram of the structure of the impeller;

[0021] Figure 4 A schematic diagram showing that a second groove is provided at the outlet end of the front shaft seal section;

[0022] Figure 5 This is a schematic diagram of a third groove being opened at the intake end of the balancing piston section.

[0023] In the figure: 1-coupling section; 2-front supporting bearing section; 3-front shaft seal section; 3-1-second groove; 4-centrifugal impeller section; 4-1-impeller; 4-1-1-wheel disc; 4-1-2-moving blades; 4-1-3-first groove; 4-1-4-impeller shaft; 4-1-5-circular cover plate; 5-balancing piston section; 5-1-third groove; 6-rear shaft seal section; 7-rear supporting bearing section; 8-thrust bearing section; 9-hollow cavity. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0025] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] See also Figures 1 to 5 As shown, the embodiment of the present application provides a multi-stage centrifugal compressor rotor structure that can adapt to an exhaust temperature of 600°C, including a coupling section 1, a front supporting bearing section 2, a front shaft seal section 3, a centrifugal impeller section 4, a balancing piston section 5, a rear shaft seal section 6, a rear supporting bearing section 7 and a thrust bearing section 8 that are axially integrated in sequence, the air inlet end of the rotor is installed in the front bearing box through the front supporting bearing section 2, and the air outlet end of the rotor is installed in the rear bearing box through the rear supporting bearing section 7; the centrifugal impeller section 4 includes multiple stages of impellers 4-1 that are axially arranged in sequence, and the adjacent two-stage impellers 4-1 are connected together by welding, and a hollow cavity 9 is provided on each side of the shaft section of the axial center position of each stage of the impeller 4-1 on the rotor main shaft; the air inlet end of the centrifugal impeller section 4 is welded to the air outlet end of the front shaft seal section 3, and the air outlet end of the centrifugal impeller section 4 is welded to the air inlet end of the balancing piston section 5.

[0028] The impellers 4-1 of each stage of the centrifugal impeller segment 4 in this embodiment are processed separately, and the shaft ends of different impellers and impellers and rotors are assembled by welding. The centrifugal impeller segment 4 and the main shaft of the rotor form an integrated structure, which ensures the safety and reliability of the shaft system of the multi-stage centrifugal compressor at an exhaust temperature of 600°C.

[0029] In this embodiment, hollow cavities 9 are provided on the rotor main shaft at the shaft sections corresponding to both sides of the impeller 4-1, mainly to ensure the feasibility of connecting the shaft ends of different impellers and the impeller and the rotor by welding process, thereby realizing the feasibility of the impeller and rotor assembly process under high temperature conditions of 600°C.

[0030] In this embodiment, the operating speed of the rotor is 3000 r / min, and the center span of the rotor bearing is 4750 mm, which ensures that the operating speed of the rotor is between the first-order critical speed and the second-order critical speed, and the avoidance rate is greater than 15%.

[0031] In a possible implementation scheme, each stage of impeller 4-1 includes an impeller shaft 4-1-4, a wheel disc 4-1-1, a plurality of moving blades 4-1-2 and an annular cover plate 4-1-5, the impeller shaft 4-1-4 is coaxially arranged with the wheel disc 4-1-1, and the two ends of the impeller shaft 4-1-4 are respectively located on both sides of the wheel disc 4-1-1, the plurality of moving blades 4-1-2 are evenly arranged circumferentially on one side of the wheel disc 4-1-1, the wheel disc 4-1-1, the impeller shaft 4-1-4 and the plurality of moving blades 4-1-2 are integrally processed; the annular cover plate 4-1-5 is welded to the plurality of moving blades 4-1-2, and a plurality of air passages are formed between the annular cover plate 4-1-5, the wheel disc 4-1-1 and the plurality of moving blades 4-1-2; two adjacent stages of impellers 4-1 are welded together through the impeller shaft 4-1-4.

[0032] In this embodiment, the coupling section 1, the front support bearing section 2, the front shaft seal section 3, the multi-stage impeller shaft 4-1-4, the balance piston section 5, the rear shaft seal section 6, the rear support bearing section 7 and the thrust bearing section 8 together constitute the main shaft of the rotor; since the wheel disc 4-1-1 and the impeller shaft 4-1-4 are made integrally, each stage of the impeller 4-1 and the rotor main shaft form an integrated structure.

[0033] In a possible implementation scheme, the end faces of both ends of the impeller shaft 4-1-4 are respectively provided with a coaxially arranged first groove 4-1-3, the end face of the outlet end of the front shaft seal section 3 is provided with a second groove 3-1, and the end face of the inlet end of the balance piston section 5 is provided with a third groove 5-1. The first groove 4-1-3 at the inlet end of the first-stage impeller 4-1 and the second groove 3-1 of the front shaft seal section 3 form a hollow cavity 9, the first groove 4-1-3 between the two adjacent impellers 4-1 forms a hollow cavity 9, and the first groove 4-1-3 at the outlet end of the last-stage impeller 4-1 and the third groove 5-1 of the balance piston section 5 form a hollow cavity 9.

[0034] In this embodiment, grooves are formed on both sides of the impeller shaft 4-1-4 mainly to ensure the feasibility of welding processes between impellers and between the impeller and the rotor shaft end. Specific welding grooves are processed on two adjacent groove end faces, and the rotor sections are connected into one by welding.

[0035] In a possible implementation, the centrifugal impeller section 4 includes a four-stage impeller 4-1. Along the air inlet direction of the rotor, the outer diameters of the four-stage impeller 4-1 are 1430 mm, 1391 mm, 1296 mm and 1211 mm respectively.

[0036] The rotor in this embodiment adopts a 4-stage closed centrifugal impeller structure. As the outlet temperature of the 4-stage impeller 4-1 gradually increases, the outer diameter of the 4-stage impeller 4-1 gradually decreases in order to reduce the centrifugal stress.

[0037] The compressor in this embodiment adopts a multi-stage small enthalpy drop solution, and uses a four-stage centrifugal impeller to achieve a pressure increase of a total pressure ratio of 2.5, effectively reducing the outer diameter of the impeller under the same design conditions and reducing the stress on the centrifugal impeller.

[0038] In a possible implementation, the inlet hub diameters of the multiple moving blades 4-1-2 of the four-stage impeller 4-1 are equal, both being 480 mm.

[0039] In a possible implementation, the outer diameters of the impeller shafts 4-1-4 of the four-stage impeller 4-1 are equal, both being 429 mm.

[0040] In a possible implementation, the wall thickness of the rotor portion corresponding to the hollow cavity 9 is 40 mm.

[0041] In this embodiment, the rotor adopts a hollow structure at the welding position, and the single-side wall thickness is 40 mm to ensure the feasibility of welding.

[0042] In a possible implementation, the journals of the front support bearing segment 2 and the rear support bearing segment 7 are 354.9 mm.

[0043] In a possible implementation scheme, the rotor is made of steel of type x13CrMoCoVNbNB9-2-1.

[0044] In this embodiment, the rotor main shaft and the impeller 4-1 are made of the same material, both of which are x13CrMoCoVNbNB9-2-1. On the one hand, this ensures that the rotor main shaft and the impeller have excellent mechanical properties at high temperatures, and on the other hand, it avoids the use of nickel-based high-temperature alloys, thereby reducing the processing difficulty of the centrifugal impeller 4-1.

[0045] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A multi-stage centrifugal compressor rotor structure adapted to an exhaust temperature of 600°C, characterized in that: The invention comprises a coupling section (1), a front support bearing section (2), a front shaft seal section (3), a centrifugal impeller section (4), a balancing piston section (5), a rear shaft seal section (6), a rear support bearing section (7) and a thrust bearing section (8) which are axially connected in sequence, wherein the air inlet end of the rotor is installed in the front bearing box via the front support bearing section (2), and the air outlet end of the rotor is installed in the rear bearing box via the rear support bearing section (7); the centrifugal impeller section (4) comprises a plurality of impellers (4-1) which are axially arranged in sequence, two adjacent impellers (4-1) are connected together by welding, and a hollow cavity (9) is provided on each side of the shaft section at the axial center position of each impeller (4-1) on the rotor main shaft; the air inlet end of the centrifugal impeller section (4) is welded to the air outlet end of the front shaft seal section (3), and the air outlet end of the centrifugal impeller section (4) is welded to the air inlet end of the balancing piston section (5); Each stage of the impeller (4-1) comprises an impeller shaft (4-1-4), a wheel disc (4-1-1), a plurality of moving blades (4-1-2) and an annular cover plate (4-1-5), wherein the impeller shaft (4-1-4) and the wheel disc (4-1-1) are coaxially arranged, and the two ends of the impeller shaft (4-1-4) are respectively located on both sides of the wheel disc (4-1-1), and the plurality of moving blades (4-1-2) are evenly arranged on one side of the wheel disc (4-1-1) in the circumferential direction. The wheel disc (4-1-1), the impeller shaft (4-1-4) and the plurality of moving blades (4-1-2) are integrally processed; the annular cover plate (4-1-5) is welded to the plurality of moving blades (4-1-2), and a plurality of air passages are formed between the annular cover plate (4-1-5), the wheel disc (4-1-1) and the plurality of moving blades (4-1-2); two adjacent stages of impellers (4-1) are welded together via the impeller shaft (4-1-4); The end surfaces of both ends of the impeller shaft (4-1-4) are respectively provided with a first groove (4-1-3) arranged coaxially, the end surface of the outlet end of the front shaft seal section (3) is provided with a second groove (3-1), and the end surface of the inlet end of the balance piston section (5) is provided with a third groove (5-1); the first groove (4-1-3) at the inlet end of the first-stage impeller (4-1) and the second groove (3-1) of the front shaft seal section (3) form a hollow cavity (9), the first groove (4-1-3) between two adjacent stages of impellers (4-1) form a hollow cavity (9), and the first groove (4-1-3) at the outlet end of the last-stage impeller (4-1) and the third groove (5-1) of the balance piston section (5) form a hollow cavity (9); The centrifugal impeller section (4) comprises a four-stage impeller (4-1), and along the air inlet direction of the rotor, the outer diameters of the four-stage impeller (4-1) are 1430 mm, 1391 mm, 1296 mm and 1211 mm respectively; The inlet hub diameters of the multiple moving blades (4-1-2) of the four-stage impeller (4-1) are equal.

2. A multi-stage centrifugal compressor rotor structure adapted to an exhaust temperature of 600°C according to claim 1, characterized in that: The outer diameters of the impeller shafts (4-1-4) of the four-stage impellers (4-1) are the same, both being 429 mm.

3. A multi-stage centrifugal compressor rotor structure adapted to an exhaust temperature of 600°C according to claim 2, characterized in that: The wall thickness of the rotor portion corresponding to the hollow cavity (9) is 40 mm.

4. A multi-stage centrifugal compressor rotor structure adapted to an exhaust temperature of 600°C according to claim 3, characterized in that: The journals of the front support bearing section (2) and the rear support bearing section (7) are 354.9 mm.

5. A multi-stage centrifugal compressor rotor structure adapted to an exhaust temperature of 600°C according to claim 4, characterized in that: The material of the rotor is x13CrMoCoVNbNB9-2-1 steel.

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