Expander capable of preventing large adjustable nozzle blade from rotating and being blocked and convenient to assemble, disassemble and maintain

Abstract

The utility model discloses an expansion machine capable of preventing a large adjustable nozzle blade from rotating and being blocked and convenient to assemble, disassemble and maintain. The expansion machine comprises an end cover chamber, the end cover chamber is respectively communicated with the air inlet channel and the air outlet channel; the end cover chamber is also provided with an adjustable nozzle; a rotor is arranged in the adjustable nozzle; a diffusion outlet pipe is arranged on the outer wall of the end cover chamber; an end cover cavity is formed in the diffusion outlet pipe; a first threaded hole is horizontally formed in the inner side of the adjustable nozzle; a horizontally arranged rotating pin is arranged in the first threaded hole; the rotating pin is positioned in the end cover cavity; a second threaded hole is horizontally formed in the outer side of the adjustable nozzle; according to the utility model, the purpose of assembling and disassembling the integral adjustable nozzle can be achieved without hoeing pearlife of the small cold box of the expansion machine, so that the equipment and labor costs caused by maintenance each time are reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field related to the improvement of expanders, and particularly relates to an expander which can prevent the blades of a large adjustable nozzle from being rotationally jammed and is convenient for assembly, disassembly and maintenance. Background Art

[0002] Turbo expanders are widely used in industries such as chemical engineering, iron and steel, glass and metallurgy. They are key components necessary for obtaining cold energy in air separation equipment, natural gas liquefaction separation equipment, cryogenic crushing equipment, etc., and are the heart to ensure the stable operation of the whole set of equipment; they provide almost all the cold energy in the separation equipment, and their performance directly determines the energy consumption and reliability of the separation equipment. In a turbo expander, the component that has the greatest impact on efficiency is the nozzle. When the nozzle speed coefficient increases by 1%, the efficiency of the expander basically increases by 1%; therefore, ensuring the normal and stable operation of the nozzle has become an important indicator for judging the performance of the expander.

[0003] Currently, in air separation equipment, considering the purpose of adjusting cold energy and also meeting the requirements of operating under various working conditions, it is generally required that the gas volume of the expander can be adjusted. Generally, the following several adjustment methods are adopted: unit throttling adjustment - reducing the inlet pressure; partial admission adjustment - closing some nozzles; rotating nozzle blade adjustment; moving nozzle blade adjustment; adjusting the height of the nozzle blade; hybrid adjustment by combining multiple units.

[0004] Currently, in separation equipment, the vast majority of the supporting turbo expanders adopt rotating nozzle blade adjustment, which belongs to a pure quantity adjustment with an effective utilization coefficient of 1. This type of expander has the advantages of convenient operation, good adjustment performance, stepless adjustment, stable operation, and suitability for operation under various working conditions; currently, as the scale of air separation equipment is getting larger and larger, the shape of the expander is also getting larger and larger, the shape of the nozzle blade also becomes larger accordingly, and the weight of the components is also getting heavier. When the outer diameter of the expansion wheel exceeds 240 mm, the weight of the adjustable nozzle component can reach more than 150 kg. Even through reasonable material and structure optimization combinations, it is very difficult to reduce the weight by much, and the assembly weight of the adjustable nozzle will also exceed 80 kg, exceeding the assembly capacity of an average worker to carry a heavy object of about 80 kg. Therefore, large adjustable nozzle components are assembled and disassembled as a whole; when adjusting the nozzle, first, the actuator moves vertically up and down reciprocally. There are holes on the pull rod of the actuator, which cooperate with the guide rod of the adjustable nozzle to drive the rotating disc to rotate. There are 8 long circular holes symmetrically arranged along the center on the end face of the rotating disc, and there are two holes on the nozzle blade. One hole is provided with a round pin through interference fit, and this round pin is inserted into the long circular hole on the rotating disc. The other hole is in clearance fit with the fixed pin on the positioning disc. When the rotating disc rotates around the axis, it drives the nozzle blade to rotate around the fixed pin on the positioning disc, thus changing the inclination angle of the nozzle blade, and thereby changing the width of the nozzle throat and the total flow area.

[0005] In the current large-scale adjustable nozzle turbine expander, in order to improve the efficiency of the nozzle, the axial clearance of the components of the adjustable nozzle is relatively small, generally about 0.15 mm, to ensure that the rotating blades will not be jammed; during operation, the blades are not subject to axial force, and the total axial force received by both end faces of the rotating disk is directed towards the cover plate side, so the friction between the rotating disk and the cover plate end face is serious; considering the low-temperature state during operation and the requirements of wear resistance, the nozzle blades, positioning disk and rotating disk are all made of martensitic steel, and their hardness is relatively close. When the outer shape of the nozzle blade is small, due to the short width of the mating end face between the rotating disk and the cover plate, even if there is a little contact during adjustment, it can still be extruded and rotated; when the outer shape of the nozzle blade is large, the flatness of the end face has a greater impact on the contact part during relative rotation. When the nozzle is rotated frequently, it is very easy for the end face of the rotating disk and the cover plate to be deformed due to contact, resulting in end face extrusion damage. The damaged particles are very easy to jam the rotating disk and the cover plate, and then a vicious cycle occurs. The particles stuck on the end faces of the rotating disk and the cover plate make the perpendicularity of the other end face of the rotating disk to the rotation axis worse, resulting in rotational extrusion deformation of the end faces of the rotating disk and the blade, and then the other end face of the blade also undergoes extrusion deformation with the end face of the positioning disk, ultimately causing the rotating disk and the blade to be jammed due to extrusion deformation, and the adjustable nozzle cannot be rotated and adjusted, and disassembly and repair are required; since the main body of the large-scale expander weighs several tons, it cannot be disassembled manually and a steam crane must be used to complete it; generally, it takes at least two days to repair and replace the nozzle components. If there are no corresponding spare parts, the maintenance cycle will be even longer, which may cause the complete set of equipment to malfunction.

[0006] The large-scale adjustable nozzle of the existing conventional turbine expander is connected to the actuator through a universal joint. Since the universal joint structure consists of a horizontal pin and a vertical pin, the position of the pin hole of this structure cannot be fixed, increasing the centering assembly difficulty during the assembly of the actuator and the connecting rod. Therefore, only after the adjustable nozzle assembly is placed into the volute can the connecting rod and the actuator be connected manually; when maintenance is required, the existing conventional expander needs to first manually enter the cold box to remove the sand, which not only consumes a lot of time but also easily affects the safety of the workers.

[0007] Chinese Patent ZL201420162676.6 discloses a nozzle structure of a turboexpander, which is only applicable to the occasion where the inner diameter of the nozzle blade is less than 180 mm. When the outer shape of the nozzle increases, due to the increased distance of blade rotation, it is easy to have the situation of friction jamming with the positioning disk or the rotating disk during the adjustment of rotation; at the same time, during on-site assembly, due to the installation stress existing in the original structure during assembly, it is also easy to cause the blade to deform and jam, resulting in repeated disassembly and assembly, and it cannot be adjusted frequently during use, affecting the use performance, and causing the expander to fail to operate stably for one year, seriously affecting the stable operation of the entire air separation product.

[0008] Chinese Patent ZL202321993939.3 discloses an expander that is easy to maintain. By splitting the heaviest part of the nozzle assembly - the positioning disk - into two parts and breaking it into smaller parts, the effective weight during nozzle installation is effectively controlled within the controllable range of a single worker, ensuring the assembly quality and reducing the assembly time; however, when the diameter of the expansion wheel is greater than 240 mm, the weight of the adjustable nozzle component can reach more than 150 kg. Even through reasonable material and structural optimization combinations, the assembly weight of the adjustable nozzle will exceed 80 kg, exceeding the assembly capacity of an average worker to carry a heavy object of about 80 kg. Therefore, large adjustable nozzle components are disassembled and assembled as a whole.

[0009] Therefore, we have developed an expander that can prevent the rotation and jamming of the blades of a large adjustable nozzle and is easy to disassemble, assemble and maintain. Summary of the Invention

[0010] The purpose of the present utility model is to provide an expander that can prevent the rotation and jamming of the blades of a large adjustable nozzle and is easy to disassemble, assemble and maintain.

[0011] To achieve the above purpose, the present utility model provides the following technical solutions:

[0012] An expander that can prevent the rotation and jamming of the blades of a large adjustable nozzle and is easy to disassemble, assemble and maintain, including an end cover chamber; the end cover chamber is respectively communicated with an air inlet channel and an air outlet channel; the end cover chamber is also provided with an adjustable nozzle; a rotor is arranged inside the adjustable nozzle; an expansion outlet pipe is arranged on the outer wall of the end cover chamber; an end cover cavity is arranged inside the expansion outlet pipe; a first threaded hole is horizontally arranged inside the adjustable nozzle; a rotating pin arranged horizontally is arranged inside the first threaded hole; the rotating pin is located inside the end cover cavity; a second threaded hole is horizontally arranged on the outside of the adjustable nozzle; the second threaded hole can be used to horizontally install a special lifting stud.

[0013] Preferably, a fastening nut is also arranged on the rotating pin to fix the rotating pin in the first threaded hole.

[0014] Preferably, the adjustable nozzle comprises a first positioning disk; a second threaded hole is horizontally provided on the outer side of the first positioning disk, and the special hoisting stud is only installed during hoisting; a rotating blade is provided on the inner side of the first positioning disk; a sliding disk is provided on the inner side of the rotating blade; a positioning sleeve is provided on the inner side of the sliding disk; a friction-reducing positioning disk is provided inside the positioning sleeve; a cover plate is provided on the inner side of the friction-reducing positioning disk; and the cover plate is fixed to the friction-reducing positioning disk by fixing screws.

[0015] Preferably, the friction-reducing positioning disk is in an annular shape, and screw holes are evenly distributed on the inner side of the friction-reducing positioning disk; the fixing screws are respectively matched with the corresponding screw holes to realize the fixation of the cover plate and the friction-reducing positioning disk.

[0016] Preferably, the first threaded hole is provided on the sliding disk, and a through hole is provided on the cover plate for the rotating pin to pass through.

[0017] Preferably, the friction-reducing positioning disk is made of tin bronze.

[0018] Preferably, the total axial clearance between the first positioning disk 51, the rotating blade 52, the sliding disk 54 and the friction-reducing positioning disk 53 is 0.20 - 0.30 mm.

[0019] Preferably, an end cover plate is provided on the diffuser outlet pipe; the end cover plate seals the end cover cavity.

[0020] Preferably, one end of the rotating pin is provided with a thread, and the other end is a slender tapered portion, which is convenient for being easily inserted into the waist-shaped hole of the actuator structure during assembly and is also convenient for external observation during installation.

[0021] Compared with the prior art, the present utility model provides an expander that can prevent the blades of a large adjustable nozzle from being stuck in rotation and is convenient for disassembly, assembly and maintenance, and has the following beneficial effects:

[0022] A. By adding a friction-reducing positioning disk made of tin bronze between the cover plate and the sliding disk of the adjustable nozzle, it is possible to prevent the phenomena of adhesion and jamming of the sliding disk, blade, positioning disk and cover plate when the rotating blade rotates;

[0023] B. The axial clearance of the adjustable component is increased to about 0.25 mm. The axial clearance is a key assembly experience parameter. When the outer shape of the nozzle blade increases, the outer shapes of the sliding disk, positioning disk and cover plate also increase accordingly, and the manufacturing precision index and geometric tolerance value will also become larger accordingly. If the axial clearance still adopts the value of the small outer shape nozzle blade, it is easy to cause the blade to adhere and jam when rotating the nozzle blade. Therefore, by correspondingly increasing the axial clearance, the blade will rotate more flexibly and no jamming phenomenon will occur again;

[0024] C. The overall disassembly and assembly of the adjustable nozzle component can be achieved through the rotating pin and the special lifting stud;

[0025] D. It is possible to achieve the purpose of disassembling and assembling the overall adjustable nozzle without removing the perlite sand in the small cold box of the expander. This not only reduces the equipment and labor costs brought by each overhaul but also saves at least two days of time. The comprehensive cost savings are at least more than 30,000 yuan, improving the economy of the equipment. At the same time, it can ensure that the operation of the expander meets the requirements of the air separation equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 FIG. 9 is a schematic cross-sectional structure view of an expander that prevents the blades of a large adjustable nozzle from rotating and jamming and is convenient for disassembly, assembly, and maintenance according to the present invention;

[0027] Figure 2 FIG. 13 is an enlarged schematic structure view of an adjustable nozzle of an expander that prevents the blades of a large adjustable nozzle from rotating and jamming and is convenient for disassembly, assembly, and maintenance according to the present invention;

[0028] FIG. 3 is Figure 2 the enlarged A-A cross-sectional view in;

[0029] Figure 4 FIG. 22 is an enlarged front view of a friction-reducing positioning disk of an adjustable nozzle of an expander that prevents the blades of a large adjustable nozzle from rotating and jamming and is convenient for disassembly, assembly, and maintenance according to the present invention;

[0030] FIG. 5 is an enlarged cross-sectional view of a friction-reducing positioning disk of an adjustable nozzle of an expander that prevents the blades of a large adjustable nozzle from rotating and jamming and is convenient for disassembly, assembly, and maintenance according to the present invention;

[0031] In the figure: 1. End cover chamber; 2. Diffuser outlet pipe; 3. Intake passage; 4. Exhaust passage; 5. Adjustable nozzle; 6. End cover cavity; 7. End cover plate; 8. Rotating pin; 51. First positioning disk; 52. Rotating blade; 53. Friction-reducing positioning disk; 54. Sliding disk; 55. Positioning sleeve; 56. Cover plate; 57. Fastening nut; 58. Fixing screw; 59. First threaded hole; 60. Second threaded hole; 61. Special lifting stud; 531. Screw hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] As Figure 1-5As shown in the figure, the utility model provides an expander which can prevent the blades of a large adjustable nozzle from being rotationally jammed and is convenient for disassembly, assembly and maintenance, comprising an end cover chamber 1; the end cover chamber 1 is respectively communicated with an air inlet passage 3 and an air outlet passage 4; the end cover chamber 1 is further provided with an adjustable nozzle 5; a rotor (not marked) is arranged in the adjustable nozzle 5; during operation, air flows into the end cover chamber 1 through the air inlet passage 3, is diffused and then flows out through the air outlet passage 4; an expanded outlet pipe 2 is arranged on the outer wall of the end cover chamber 1; an end cover cavity 6 is arranged in the expanded outlet pipe 2; an end cover plate 7 is arranged on the expanded outlet pipe 2; the end cover plate 7 seals the end cover cavity 6; a first threaded hole 59 is horizontally arranged on the inner side of the adjustable nozzle 5; a rotating pin 8 horizontally arranged is arranged in the first threaded hole 59; a fastening nut 57 is further arranged on the rotating pin 8 for fixing the rotating pin 8 in the first threaded hole 59; the rotating pin 8 is located in the end cover cavity 6; the adjustable nozzle 5 comprises a first positioning disc 51; a second threaded hole 60 is horizontally arranged on the outer side of the first positioning disc 51; the second threaded hole 60 can be used for horizontally installing a special lifting stud (not shown), and the special lifting stud is only installed during lifting; a rotating blade 52 is arranged on the inner side of the first positioning disc 51; a sliding disc 54 is arranged on the inner side of the rotating blade 52; a positioning sleeve 55 is arranged on the inner side of the sliding disc 54; a friction-reducing positioning disc 53 is arranged in the positioning sleeve 55; a cover plate 56 is arranged on the inner side of the friction-reducing positioning disc 53; the cover plate 56 is fixed on the friction-reducing positioning disc 53 through fixing screws 58.

[0034] The friction-reducing positioning disc 53 is in an annular shape, and screw holes 531 are evenly distributed on the inner side of the friction-reducing positioning disc 53; the fixing screws 58 are respectively matched with the corresponding screw holes 531 to realize the fixation of the cover plate 56 and the friction-reducing positioning disc 53.

[0035] In this embodiment, the first threaded hole 59 is arranged on the sliding disc 54, and through holes (not marked) are arranged on the cover plate 56 for the rotating pin 8 to pass through.

[0036] In this embodiment, one end of the rotating pin 8 is provided with threads, and the other end is a slender conical part, which is convenient for being easily inserted into the kidney-shaped hole of the actuating structure during assembly and is also convenient for external observation during installation.

[0037] In this embodiment, the friction-reducing positioning disc 53 is made of tin bronze material; in the prior art, the cover plate and the positioning disc, which are most likely to be jammed, are made of the same stainless steel and are easy to be embedded. However, for the new friction pair: there is a hardness difference between the friction-reducing positioning disc 53 and the cover plate 56, which has good wear resistance, compliance and fitting performance, and the phenomenon of bonding and jamming will no longer occur.

[0038] In this embodiment, the total axial clearance between the first positioning disc 51, the rotating blade 52, the sliding disc 54 and the anti-friction positioning disc 53 is 0.20 - 0.30 mm.

[0039] When installing the adjustable nozzle component, first screw the threads of the two special lifting studs 61 into the screw holes (not shown) of the turbine volute, and then screw the threads of the two special lifting studs 61 into the two second threaded holes 60 on the same circumference as the stepped holes of the first positioning disc 51. Tie the ropes of the lifting tool firmly to these two special lifting studs 61. When lifting the entire adjustable nozzle component by air hoist, align the outer stepped holes of the first positioning disc 51 with the two special lifting studs 61 that have been installed into the screw holes of the turbine volute as the positioning reference for movement. Push the two special lifting studs 61 that are later installed into the two second threaded holes 60 of the first positioning disc 51 by hand along the axial direction to axially move the entire adjustable nozzle component. When observing that the tapered part of the rotating pin 8 on the adjustable nozzle enters the turbine volute, and the outer circle of the cover plate of the adjustable nozzle also starts to enter the inner hole of the turbine volute, adjust the installation position of the adjustable nozzle until the tapered part of the rotating pin 8 is inserted into the kidney-shaped hole of the actuator. At this time, the remaining 14 screws in the stepped holes can be screwed in, and then the two special lifting studs are removed and replaced with two screws, achieving the purpose of installing the adjustable nozzle without removing the perlite sand.

[0040] Compared with the prior art, the present utility model has the following beneficial effects:

[0041] A. By adding an anti-friction positioning disc made of tin bronze between the cover plate and the sliding disc of the adjustable nozzle, when rotating the blade, the phenomenon of sticking and jamming of the sliding disc, blade, positioning disc and cover plate will no longer occur;

[0042] B. Increase the axial clearance of the adjustable component to about 0.25 mm. The axial clearance is a key assembly experience parameter. When the outer shape of the nozzle blade increases, the outer shapes of the sliding disc, positioning disc and cover plate also increase accordingly, and the manufacturing precision index and geometric tolerance value will also increase accordingly. If the axial clearance still uses the value of the small outer shape nozzle blade, when rotating the nozzle blade, it is easy to cause the blade to stick and jam. Therefore, increasing the axial clearance accordingly will make the blade rotate more flexibly and no longer jam;

[0043] C. The purpose of overall disassembly and assembly of the adjustable nozzle component can be achieved through the rotating pin 8 and the special lifting stud 61;

[0044] D. It is possible to achieve the purpose of installing and disassembling the integral adjustable nozzle without removing the perlite sand of the small cold box of the expander, which not only reduces the equipment and labor costs brought by each overhaul, but also saves at least two days or more of time. The comprehensive cost savings are at least more than 30,000 yuan, improving the economy of the equipment. At the same time, it can ensure that the operation of the expander meets the requirements of the air separation equipment.

[0045] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An expander that prevents the blades of a large adjustable nozzle from getting stuck in rotation and is convenient for installation, disassembly and maintenance, comprising an end cover chamber; the end cover chamber is respectively communicated with an air inlet passage and an air outlet passage; the end cover chamber is further provided with an adjustable nozzle; a rotor is arranged in the adjustable nozzle; a diffuser outlet pipe is arranged on the outer wall of the end cover chamber; an end cover cavity is arranged in the diffuser outlet pipe; and it is characterized in that: A first threaded hole is horizontally provided on the inner side of the adjustable nozzle; a rotating pin horizontally arranged is provided in the first threaded hole; the rotating pin is located in the end cover cavity; a second threaded hole is horizontally provided on the outer side of the adjustable nozzle; the second threaded hole can be used to horizontally install a special lifting stud.

2. The expander for preventing the large adjustable nozzle vane from being rotationally jammed and facilitating disassembly, installation and maintenance according to claim 1, wherein: A fastening nut is further provided on the rotating pin for fixing the rotating pin in the first threaded hole.

3. The expander for preventing the large adjustable nozzle vane from being rotationally jammed and facilitating assembly, disassembly and maintenance according to claim 1, wherein: The adjustable nozzle includes a first positioning disc; a second threaded hole is horizontally provided on the outer side of the first positioning disc, and the special lifting stud is only installed during lifting; a rotating blade is provided on the inner side of the first positioning disc; a sliding disc is provided on the inner side of the rotating blade; a positioning sleeve is provided on the inner side of the sliding disc; a friction-reducing positioning disc is provided in the positioning sleeve; a cover plate is provided on the inner side of the friction-reducing positioning disc; the cover plate is fixed to the friction-reducing positioning disc by fixing screws.

4. The expander for preventing the large adjustable nozzle vane from being rotationally jammed and facilitating disassembly, installation and maintenance according to claim 3, wherein: The friction-reducing positioning disc is annular, and screw holes are evenly distributed on the inner side of the friction-reducing positioning disc; the fixing screws are respectively matched with the corresponding screw holes to realize the fixation of the cover plate and the friction-reducing positioning disc.

5. The expander for preventing the large adjustable nozzle vane from being rotationally jammed and facilitating assembly, disassembly and maintenance according to claim 3, characterized in that: The first threaded hole is provided on the sliding disc, and a through hole is provided on the cover plate for the rotating pin to pass through.

6. The expander for preventing the large adjustable nozzle vane from being rotationally jammed and facilitating disassembly, installation and maintenance according to claim 3, wherein: The friction-reducing positioning disc is made of tin bronze material.

7. The expander for preventing the large adjustable nozzle vane from jamming during rotation and facilitating assembly, disassembly and maintenance according to claim 3, characterized in that: The total axial clearance between the first positioning disc (51), the rotating blade (52), the sliding disc (54) and the friction-reducing positioning disc (53) is 0.20 - 0.30 mm.

8. The expander for preventing the rotation jamming of the large adjustable nozzle blades and facilitating the disassembly, assembly and maintenance according to claim 1, characterized in that: An end cover plate is provided on the diffuser outlet pipe; the end cover plate seals the end cover cavity.

9. The expander for preventing the large adjustable nozzle vane from being rotationally jammed and facilitating disassembly, installation and maintenance according to claim 2, wherein: One end of the rotating pin is provided with a thread, and the other end is a slender conical part, which is convenient for being easily inserted into the kidney-shaped hole of the actuator during assembly and is also convenient for external observation during installation.

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