A centrifugal compressor

Abstract

The present invention discloses a centrifugal compressor, comprising: a casing, the casing is provided with an isolation gas inlet groove; a compressor main shaft; a dry gas sealing part, arranged between the casing and the compressor main shaft, the dry gas sealing part is provided with a comb-tooth sealing structure; a locking element, arranged in the isolation gas inlet groove, for limiting the movement of the comb-tooth sealing structure relative to the casing. The present invention places the locking element in the isolation gas inlet groove on the casing, and after the structure is improved, the original outermost isolation gas inlet groove and the card slot are structurally combined into one, reducing the axial dimension by about 10%. At the same time, it is easy to install and disassemble, reduces the amount of screws, reduces the risk of screws falling, simplifies the structure of the unit, and reduces the weight.

Description

Technical Field

[0001] The invention relates to the field of sealing, and in particular to a centrifugal compressor. Background Art

[0002] Dry gas seals are generally used as shaft end seals in centrifugal compressors for flammable, explosive, toxic and hazardous media. As an indispensable component of centrifugal compressors, the structural dimensions and processing methods of the dry gas seal area affect the overall dimensions and rotor dynamics of the unit. With the increasing demand for large and ultra-large units, the miniaturization of the structure of the unit's peripheral components and the convenience of processing are becoming increasingly important.

[0003] Patent CN204186630U discloses a dry gas seal structure and a multi-shaft centrifugal compressor. The multi-shaft centrifugal compressor includes a dry gas seal structure, which includes a dry gas seal body and a rotor, and also includes a labyrinth seal and an oil slinger ring. The labyrinth seal is fixed on the dry gas seal body by bolts, and the oil slinger ring is arranged on the rotor. The inner ring of the labyrinth seal and the outer ring of the oil slinger ring are close to each other, and the outer ring of the oil slinger ring is provided with oil slinger ring teeth, and the oil slinger ring teeth are opposite to the sealing teeth on the inner ring of the labyrinth seal, or the oil slinger ring teeth are at a certain angle to the sealing teeth on the inner ring of the labyrinth seal. The patent uses a labyrinth seal integrated with a dry gas seal body, which can reduce the axial length of the dry gas seal and the rotor, improve the stability of the rotor, and has a simple and compact structure, easy installation, and strong practicality.

[0004] Under the premise of not changing the core structure of the dry gas seal and meeting the existing functions, reducing the axial dimension of the dry gas seal area, reducing the casing volume, reducing the processing steps and reducing the processing amount through design optimization is still a research hotspot for personnel in this technical field. Summary of the invention

[0005] In view of this, the present invention provides a centrifugal compressor.

[0006] Specifically, the following technical solutions are included:

[0007] A centrifugal compressor, comprising:

[0008] A casing, wherein the casing is provided with an isolation air inlet groove;

[0009] Compressor main shaft;

[0010] A dry gas sealing portion, arranged between the casing and the compressor main shaft, the dry gas sealing portion being provided with a comb teeth sealing structure;

[0011] A locking element is disposed in the isolation air inlet groove and is used to limit the movement of the comb seal structure relative to the housing.

[0012] Furthermore, the locking element is provided with a protruding structure and an anti-rotation groove;

[0013] A groove structure is provided in the isolation gas inlet groove;

[0014] The comb teeth sealing structure is provided with an anti-rotation element;

[0015] in,

[0016] The protrusion structure matches the groove structure and can limit the rotation of the locking element relative to the housing. The anti-rotation element matches the anti-rotation groove and can limit the rotation of the comb teeth sealing structure relative to the locking element.

[0017] Furthermore, the locking element is a circular ring structure, and the protruding structure is arranged on the outer edge of the locking element;

[0018] The isolation gas inlet groove is an annular groove, and the groove structure is arranged at the bottom of the annular groove;

[0019] The anti-rotation element and the comb teeth sealing structure are integrally formed.

[0020] Furthermore, the anti-rotation groove is arranged on the inner edge of the locking element and is arranged opposite to the protruding structure.

[0021] Furthermore, the protruding structure is located above the locking element.

[0022] Furthermore, an annular space is formed between the locking element and the isolation gas inlet groove, and an air flow channel is provided on the comb-teeth sealing structure;

[0023] The locking element is provided with an air flow hole in the circumference thereof. The air flow hole penetrates the locking element in a radial direction, and the air flow hole connects the annular space and the air flow channel.

[0024] Furthermore, the outer edge of the locking element is configured as an annular stepped structure, and the annular space is formed between the annular stepped structure and the isolation gas inlet groove.

[0025] Further, the locking element comprises a coaxially arranged low-order portion and a high-order portion;

[0026] The protruding structure is arranged at the high-order portion, and the air flow hole penetrates through the low-order portion.

[0027] Further, it comprises a first positioning element and a second positioning element, the locking element comprises a bottom plate, a left side plate, a right side plate and a top plate, the bottom plate, the left side plate, the top plate and the right side plate abut against each other in a clockwise direction;

[0028] The first positioning element is disposed at a connection between the left side plate and the top plate, and the second positioning element is disposed at a connection between the right side plate and the top plate.

[0029] Further, the two ends of the top plate are provided with first notches, the end of the left side plate close to the top plate is provided with a second notch matching the first notch, the first notch and the second notch together form a first positioning hole, and the first positioning element is penetrated through the first positioning hole to connect the top plate and the left side plate;

[0030] A third notch matching the first notch is provided at one end of the right side plate close to the top plate, the first notch and the third notch together form a second positioning hole, and the second positioning element is passed through the second positioning hole to connect the top plate and the right side plate.

[0031] The beneficial effects of the technical solution provided by the embodiment of the present invention include at least:

[0032] (1) The present invention places the locking element in the isolation air inlet groove on the casing. After the structure is improved, the original outermost isolation air inlet groove and the card slot are structurally combined into one, reducing the axial dimension by about 10%. At the same time, it is easy to install and disassemble, reduces the number of screws, reduces the risk of screws falling, simplifies the structure of the unit, and reduces the weight.

[0033] (2) The present invention realizes anti-rotation between the housing and the locking element by setting a protrusion structure and a groove structure, and realizes anti-rotation between the locking element and the comb gas sealing structure by setting an anti-rotation groove, thereby realizing overall anti-rotation. The anti-rotation measure has been structurally optimized, and the anti-rotation groove has been changed from being milled on the housing to being milled on the locking element, which reduces the processing procedures, reduces the occupation time of key large-scale key processing equipment (gantry milling, boring and milling machine), and improves the processing efficiency of the workshop.

[0034] (3) The present invention realizes the rapid positioning and installation of the locking element by setting a positioning element. The positioning element can be quickly installed by clamping with needle-nosed pliers to realize the positioning of the locking element, which is simple to operate and convenient to install. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A schematic diagram of an existing dry gas sealing portion is shown;

[0037] Figure 2 A schematic diagram of a dry gas sealing portion of the present invention is shown;

[0038] Figure 3 Shows Figure 2 Schematic diagram of the AA section structure;

[0039] Figure 4 A schematic diagram of the axial side section of the dry gas seal of the present invention is shown;

[0040] Figure 5 A schematic diagram of a locking element of the present invention is shown;

[0041] Figure 6 A schematic diagram of the axial side cross-sectional structure of the locking element of the present invention is shown;

[0042] Figure 7 A front schematic diagram of a locking element of the present invention is shown.

[0043] The reference numerals in the figures represent respectively:

[0044] A1-primary sealing air inlet groove; A2-secondary sealing air inlet groove; B1-primary sealing air exhaust groove; B2-secondary sealing air exhaust groove; C-isolation air inlet groove; 100-casing; 200-compressor main shaft; 300-dry gas sealing part; 301-comb tooth sealing structure; 301a-air flow channel; 1-locking element; 1a-bottom plate; 1b-left side plate; 1c-right side plate; 1d-top plate; 2-anti-rotation element; 3-anti-rotation pin; 4-screw; 5-card slot; 6-groove structure; 7-positioning element; 7a-first positioning element; 7b-second positioning element; 8-process hole; 9-air flow hole; 10-protrusion structure; 11-anti-rotation groove; 12-annular space; 13-low-order part; 14-high-order part; 15-first positioning hole; 16-second positioning hole.

[0045] The above drawings have shown clear embodiments of the present invention, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present invention in any way, but to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Before further describing the embodiments of the present invention in detail, the directional nouns involved in the embodiments of the present invention, such as "upper part", "lower part", "side part", etc., are Figure 1 The orientation shown in is a reference and is only used to clearly describe the structure of the embodiment of the present invention, and does not have the meaning of limiting the scope of protection of the present invention.

[0048] Unless otherwise defined, all technical terms used in the embodiments of the present invention have the same meanings as commonly understood by those skilled in the art.

[0049] To make the technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0050] like Figure 1 The figure shows a cross-sectional structure diagram of a conventional tandem dry gas seal with an intermediate comb seal in a centrifugal compressor, which usually includes six annular groove structures, from the inside to the outside, namely, the primary seal air inlet groove A1, the primary seal air exhaust groove B1, the secondary seal air inlet groove A2, the secondary seal air exhaust groove B2, the isolation air inlet groove C and the mounting card groove 5 of the locking element 1. The axial dimension of the dry gas seal area in the existing structure is relatively large, which no longer meets the requirements of the miniaturization of the component structure of the existing large units and super large units.

[0051] The structural schematic diagram of the improved dry gas sealing part of the present invention is as follows Figure 2 As shown, from Figure 2 It can be seen that the centrifugal compressor in the present invention includes a casing 100, on which an isolation gas inlet groove C is provided; a compressor main shaft 200; a dry gas sealing part 300, which is arranged between the casing 100 and the compressor main shaft 200, and the dry gas sealing part 300 is provided with a comb tooth sealing structure 301; a locking element 1, which is arranged in the isolation gas inlet groove C, and is used to limit the movement of the comb tooth sealing structure 301 relative to the casing 100. The improved structure combines the slot 5 of the locking element 1 with the isolation gas inlet groove C, shortening the axial dimension of the dry gas sealing part by about 10%, and has a compact structure and is easy to install, which is in line with the trend of miniaturization of component structures in large and super-large units. Moreover, compared with Figure 1 By comparison, it can be seen that the amount of screws used is reduced, the risk of screws falling is reduced, the structure of the unit is simplified, and the weight is reduced.

[0052] like Figures 2 to 7As shown, the locking element 1 is provided with a protruding structure 10 and an anti-rotation groove 11, the isolation air inlet groove C is provided with a groove structure 6, and the comb-tooth sealing structure 301 is provided with an anti-rotation element 2. The protruding structure 10 matches the groove structure 6, and the two are connected by snapping, which can limit the rotation of the locking element 1 relative to the housing 100; the anti-rotation element 2 matches the anti-rotation groove 11, and the two are connected by snapping, which can limit the rotation of the comb-tooth sealing structure 301 relative to the locking element 1, thereby limiting the rotation of the comb-tooth sealing structure 301 relative to the housing 100.

[0053] and Figure 1 Compared with the conventional structure, the improved structure eliminates the anti-rotation pin 3 in the existing structure, and eliminates the anti-rotation pin hole in the existing structure where the locking element 1 cooperates with the housing 100. Therefore, a processing step is reduced on the large housing 100, reducing the time occupied by key large-scale key processing equipment (gantry milling machine, boring and milling machine), and improving the processing efficiency of the workshop. At the same time, the improved structure eliminates the screw 4 in the existing structure, further reducing the difficulty of assembling the unit, especially the installation and operation space of the screw 4 between the lower part of the compressor main shaft 200 and the bearing seat is very small, which is very troublesome to disassemble and assemble before modification, but easy to install after modification, improving the assembly efficiency.

[0054] like Figure 5 As shown, the locking element 1 is a circular ring structure, and the protruding structure 10 is arranged on the outer edge of the locking element 1. Figure 3 and Figure 4 As shown, the isolation gas inlet groove C is an annular groove, and the groove structure 6 is arranged at the bottom of the annular groove. Figure 4 As shown, the anti-rotation element 2 and the comb teeth sealing structure 301 are integrally formed.

[0055] like Figure 5 As shown, the protrusion structure 10 is located above the locking element 1. The protrusion structure 10 is an eccentric arc structure protruding on the edge of the high-step portion 14, and the groove structure 6 is an eccentric arc structure recessed on the bottom edge of the isolation gas inlet groove C. Figure 3 The locking element 1 is assembled in the isolation air inlet groove C, the protruding structure 10 matches the groove structure 6, and the anti-rotation connection between the housing 100 and the locking element 1 is achieved through the snap connection between the protruding structure 10 and the groove structure 6.

[0056] The processing process of the groove structure 6 is to use a boring machine to CNC milling on the horizontally split large MCL centrifugal compressor casing. Because with the existing process means, all the ring grooves in the dry gas seal area are milled without moving the casing, so the eccentric arc groove of the groove structure 6 only needs to be realized by CNC programming to follow a non-circular trajectory. The process difficulty is low, and the processing can be completed in one clamping and tool setting, with high precision and good verticality.

[0057] like Figure 5 As shown, the anti-rotation groove 11 is arranged on the inner edge of the locking element 1 and is arranged opposite to the protruding structure 10. The anti-rotation groove 11 is radially arranged on the locking element 1 and is a semi-enclosed structure. There is a gap at the intersection of the anti-rotation groove 11 and a wall surface of one side of the locking element 1 that is perpendicular to the axial direction of the housing 100. During the installation process, after the locking element 1 is installed, the comb air sealing structure 301 is installed. During the installation process of the comb air sealing structure 301, the anti-rotation element 2 enters the anti-rotation groove 11 through the gap.

[0058] An annular space 12 is formed between the locking element 1 and the isolation gas inlet groove C, and an air flow channel 301a is provided on the comb seal structure 301. An air flow hole 9 is provided in the circumference of the locking element 1, and the air flow hole 9 penetrates the locking element 1 in the radial direction, and the air flow hole 9 connects the annular space 12 and the air flow channel 301a.

[0059] like Figures 2 to 7 As shown, the outer edge of the locking element 1 is set as an annular step structure, and the annular space 12 is formed between the annular step structure and the isolation gas inlet groove C. The locking element 1 includes a coaxially arranged low-step portion 13 and a high-step portion 14, the protruding structure 10 is arranged on the outer edge of the high-step portion 14, and the airflow hole 9 passes through the low-step portion 13. The airflow hole 9 is a semi-enclosed structure. When the locking element 1 is installed in place in the isolation gas inlet groove C, the wall surface of the isolation gas inlet groove C and the airflow hole 9 are combined to form a complete through-hole structure.

[0060] like Figure 5 As shown, it includes a positioning element 7, the positioning element 7 includes a first positioning element 7a and a second positioning element 7b (not shown in the figure), the locking element 1 includes a bottom plate 1a, a left side plate 1b, a right side plate 1c and a top plate 1d, and the bottom plate 1a, the left side plate 1b, the top plate 1d and the right side plate 1c abut against each other in a clockwise direction. The first positioning element 7a is arranged at the connection between the left side plate 1b and the top plate 1d, and the second positioning element 7b is arranged at the connection between the right side plate 1c and the top plate 1d.

[0061] like Figures 5 to 7As shown, the two ends of the top plate 1d are provided with a first notch, and the end of the left side plate 1b close to the top plate 1d is provided with a second notch matching the first notch, the first notch and the second notch together form a first positioning hole 15, and the first positioning element 7a is passed through the first positioning hole 15 to connect the top plate 1d and the left side plate 1b.

[0062] A third notch matching the first notch is provided at one end of the right side plate 1c close to the top plate 1d, and the first notch and the third notch together form a second positioning hole 16. The second positioning element 7b is passed through the second positioning hole 16 to connect the top plate 1d and the right side plate 1c.

[0063] The first positioning hole 15 and the second positioning hole 16 are axially penetrating through holes, and the first positioning element and the second positioning element are straight-groove lightweight elastic cylindrical pins, which are respectively disposed in the first positioning hole 15 and the second positioning hole 16 .

[0064] When installing the locking element 1, first install the bottom plate 1a, then install the left side plate 1b and the right side plate 1c, and finally install the top plate 1d. The top plate 1d is located at the top, and the left side plate 1b and the right side plate 1c cannot provide sufficient support force. In order to prevent the top plate 1d from falling off after letting go, a first positioning hole 15 and a second positioning hole 16 are provided. By providing the positioning element 7 in the first positioning hole 15 and the second positioning hole 16, the abutment of the positioning element 7 can provide good support and fixation for the top plate 1d, and then the anti-rotation element 2 on the comb airtight decomposition structure 301 is pushed into the anti-rotation groove 11, thus completing the complete fixation of the locking element 1.

[0065] The positioning element 7 adopts a straight groove lightweight elastic cylindrical pin, which can be inserted and pulled out with needle-nosed pliers. The operating position of the needle-nosed pliers is above the compressor shaft 200 and outside the dry gas sealing area. The space is wide, the operation is simple, convenient, and low-risk, and the locking element 1 can be quickly positioned.

[0066] like Figure 5 As shown, the locking element 1 is evenly distributed with process holes 8 in the circumference thereof, and the locking element 1 can be quickly installed and removed through the process holes 8 .

[0067] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The description and examples are to be considered exemplary only.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A centrifugal compressor, characterized in that: include: A casing, wherein the casing is provided with an isolation air inlet groove; Compressor main shaft; A dry gas sealing portion, arranged between the casing and the compressor main shaft, the dry gas sealing portion being provided with a comb teeth sealing structure; A locking element, disposed in the isolation air inlet groove, for limiting the movement of the comb seal structure relative to the housing; The locking element is provided with a protruding structure and an anti-rotation groove; A groove structure is provided in the isolation gas inlet groove; The comb teeth sealing structure is provided with an anti-rotation element; in, The protrusion structure matches the groove structure, and can limit the rotation of the locking element relative to the housing; the anti-rotation element matches the anti-rotation groove, and can limit the rotation of the comb teeth sealing structure relative to the locking element; The locking element is a circular ring structure, and the protruding structure is arranged on the outer edge of the locking element; The isolation gas inlet groove is an annular groove, and the groove structure is arranged at the bottom of the annular groove; The anti-rotation element and the comb teeth sealing structure are integrally formed.

2. A centrifugal compressor according to claim 1, characterized in that: The anti-rotation groove is arranged on the inner edge of the locking element and is arranged opposite to the protruding structure.

3. A centrifugal compressor according to claim 2, characterized in that: The protruding structure is located above the locking element.

4. A centrifugal compressor according to claim 1, characterized in that: An annular space is formed between the locking element and the isolation gas inlet groove, and an air flow channel is provided on the comb-teeth sealing structure; The locking element is provided with an air flow hole in the circumference thereof. The air flow hole penetrates the locking element in a radial direction, and the air flow hole connects the annular space and the air flow channel.

5. A centrifugal compressor according to claim 4, characterized in that: The outer edge of the locking element is configured as an annular step structure, and the annular space is formed between the annular step structure and the isolation gas inlet groove.

6. A centrifugal compressor according to claim 4, characterized in that: The locking element comprises a coaxially arranged low-order portion and a high-order portion; The protruding structure is arranged at the high-order portion, and the air flow hole penetrates through the low-order portion.

7. A centrifugal compressor according to claim 1, characterized in that: It includes a first positioning element and a second positioning element, wherein the locking element includes a bottom plate, a left side plate, a right side plate and a top plate, and the bottom plate, the left side plate, the top plate and the right side plate abut against each other in a clockwise direction; The first positioning element is disposed at a connection between the left side plate and the top plate, and the second positioning element is disposed at a connection between the right side plate and the top plate.

8. A centrifugal compressor according to claim 7, characterized in that: The top plate is provided with first notches at both ends, and the left side plate is provided with a second notch matching the first notch at one end close to the top plate, the first notch and the second notch together form a first positioning hole, and the first positioning element is passed through the first positioning hole to connect the top plate and the left side plate; A third notch matching the first notch is provided at one end of the right side plate close to the top plate, the first notch and the third notch together form a second positioning hole, and the second positioning element is passed through the second positioning hole to connect the top plate and the right side plate.

Images