CN115127020B - Large-diameter opening sealing structure suitable for low-temperature composite material storage tank - Google Patents
Large-diameter opening sealing structure suitable for low-temperature composite material storage tank Download PDFInfo
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- CN115127020B CN115127020B CN202210617853.4A CN202210617853A CN115127020B CN 115127020 B CN115127020 B CN 115127020B CN 202210617853 A CN202210617853 A CN 202210617853A CN 115127020 B CN115127020 B CN 115127020B
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- 238000007789 sealing Methods 0.000 title claims abstract description 248
- 239000002131 composite material Substances 0.000 title claims abstract description 165
- 238000003860 storage Methods 0.000 title claims abstract description 34
- 229910052751 metal Inorganic materials 0.000 claims abstract description 125
- 239000002184 metal Substances 0.000 claims abstract description 125
- 238000009434 installation Methods 0.000 claims abstract description 22
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 20
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 20
- 239000010439 graphite Substances 0.000 claims abstract description 20
- 229920001967 Metal rubber Polymers 0.000 claims abstract description 15
- 238000000034 method Methods 0.000 claims abstract description 15
- 230000008569 process Effects 0.000 claims abstract description 11
- 239000000463 material Substances 0.000 claims description 21
- 239000010935 stainless steel Substances 0.000 claims description 9
- 229910001220 stainless steel Inorganic materials 0.000 claims description 9
- 230000003746 surface roughness Effects 0.000 claims description 9
- 229910000831 Steel Inorganic materials 0.000 claims description 6
- 238000003825 pressing Methods 0.000 claims description 6
- 239000010959 steel Substances 0.000 claims description 6
- 229910000838 Al alloy Inorganic materials 0.000 claims description 4
- 239000000956 alloy Substances 0.000 claims description 4
- 210000001503 joint Anatomy 0.000 claims description 4
- 229910000851 Alloy steel Inorganic materials 0.000 claims description 3
- 238000007723 die pressing method Methods 0.000 claims description 3
- 238000005242 forging Methods 0.000 claims description 3
- 229910001026 inconel Inorganic materials 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 15
- 230000000694 effects Effects 0.000 description 8
- 229920005989 resin Polymers 0.000 description 8
- 239000011347 resin Substances 0.000 description 8
- 239000002344 surface layer Substances 0.000 description 5
- 229920000049 Carbon (fiber) Polymers 0.000 description 4
- 239000004917 carbon fiber Substances 0.000 description 4
- 238000007906 compression Methods 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 238000005056 compaction Methods 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 239000011229 interlayer Substances 0.000 description 3
- 239000007769 metal material Substances 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 230000032798 delamination Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000008093 supporting effect Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C13/00—Details of vessels or of the filling or discharging of vessels
- F17C13/06—Closures, e.g. cap, breakable member
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B43/00—Washers or equivalent devices; Other devices for supporting bolt-heads or nuts
- F16B43/001—Washers or equivalent devices; Other devices for supporting bolt-heads or nuts for sealing or insulation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B5/00—Joining sheets or plates, e.g. panels, to one another or to strips or bars parallel to them
- F16B5/02—Joining sheets or plates, e.g. panels, to one another or to strips or bars parallel to them by means of fastening members using screw-thread
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/02—Sealings between relatively-stationary surfaces
- F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
- F16J15/061—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with positioning means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/02—Sealings between relatively-stationary surfaces
- F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
- F16J15/08—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with exclusively metal packing
- F16J15/0887—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with exclusively metal packing the sealing effect being obtained by elastic deformation of the packing
- F16J15/0893—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with exclusively metal packing the sealing effect being obtained by elastic deformation of the packing the packing having a hollow profile
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/02—Sealings between relatively-stationary surfaces
- F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
- F16J15/10—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing
- F16J15/102—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing characterised by material
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/02—Sealings between relatively-stationary surfaces
- F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
- F16J15/10—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing
- F16J15/12—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing with metal reinforcement or covering
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/46—Sealings with packing ring expanded or pressed into place by fluid pressure, e.g. inflatable packings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C13/00—Details of vessels or of the filling or discharging of vessels
- F17C13/002—Details of vessels or of the filling or discharging of vessels for vessels under pressure
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Architecture (AREA)
- Fluid Mechanics (AREA)
- Gasket Seals (AREA)
Abstract
A large diameter opening seal structure for a cryogenic composite tank comprising: composite plate, metal flange, fastening bolt, etc.; a plurality of through holes are formed in the circumferential direction of the composite plate; one surface of the metal flange plate, which is in contact with the composite plate, is provided with a threaded blind hole along the circumferential direction, and sealing grooves are respectively arranged on the inner ring and the outer ring of a threaded blind hole ring formed by the threaded blind hole and are used for placing a graphite sealing ring; the metal flange plate is positioned at one side of the composite material plate; the sealing cushion blocks are circumferentially distributed on the other side of the composite material plate, and the installation positions correspond to the positions of the through holes in the composite material plate; a metal rubber composite sealing ring and a hollow metal O-shaped sealing ring are respectively arranged in the sealing grooves at two sides of the sealing cushion block; the fastening bolts are used for fixing the composite plate, the metal flange plate and the sealing cushion block. The invention improves the safety and reliability of the composite material storage tank in the use process, and the sealing structure can realize multiple disassembly and assembly.
Description
Technical Field
The invention relates to a large-diameter opening sealing structure.
Background
The composite material storage tank is a novel storage tank structure which takes carbon fiber as a reinforcing material and epoxy resin as a matrix material, the traditional composite material storage tank takes a metal layer (aluminum alloy or titanium alloy) as an inner liner, and the composite material layer is wound or laid outside, wherein the metal liner plays roles of preventing leakage and a composite material winding tool, and the composite material of the outer layer plays a role of bearing internal pressure load. The flange sealing structures at the two ends of the sealing structure adopt a conventional metal-metal sealing mode, and the sealing structure can meet the requirements by adopting a conventional scheme
With the progress of material technology and forming process, the lining-free composite material storage tank becomes the development direction of the composite material storage tank, most of the main structure of the lining-free composite material storage tank adopts composite materials, no metal lining or an internal anti-seepage layer is needed, the composite materials are used as anti-seepage structures and stress structures at the same time, the large openings at the two ends of the composite material storage tank cannot adopt a metal-metal sealing structure form, a novel composite material-metal sealing structure is needed to be developed, but due to the differences of the thermal expansion coefficients of the metal materials and the composite materials, the strength differences of the materials, the processability differences, the seepage mechanism differences and the like, the design difficulty of the sealing structure is huge, the traditional metal-metal sealing structure does not have a scheme capable of being used as a reference, and the sealing structure needs to be re-developed aiming at the characteristics of the composite materials.
The composite material is different from the metal material, the thermal expansion coefficient of the resin material is larger than that of the carbon fiber, the resin shrinkage can generate larger temperature stress at the interface between the resin material and the carbon fiber under the low temperature condition, the strain range which the composite material can bear under the action of external force can be greatly reduced, namely the brittleness of the composite material is increased under the low temperature condition. Therefore, the pressure applied to the surface of the composite material is not excessive, and the excessive pressure can cause the resin on the surface layer of the composite material to be compressed and damaged, so that the moment of the fastener is lost, the sealing gap between the metal and the composite material is increased, and the fuel is leaked. Meanwhile, the modulus and the hardness of the sealing ring material are required to be smaller than the hardness of the resin layer of the surface layer of the composite material, otherwise, the resin of the surface layer of the composite material is damaged in the compression process of the sealing ring, so that a gap is formed between the sealing ring and the composite material to cause leakage. The design of the sealing structure between the composite material and the metal flange is required to solve a plurality of problems: (1) The adopted sealing ring material has proper modulus and hardness, and the surface layer of the composite material cannot be damaged in the compression process; (2) The composite material itself cannot be machined in the form of a groove, step, etc. failure, which can cause delamination defects in the composite material and result in structural failure. (3) The sealing ring material needs to meet the performance requirements under different conditions, for example, the sealing ring in the tank needs to be compatible with fuel medium, and the problems of embrittlement, dissolution and the like do not occur. (4) The sealing structure needs to meet the requirement of reliable sealing under the condition of repeated disassembly and assembly, and the sealing surfaces cannot adopt an undetachable cementing mode. (5) The composite material has poor performance uniformity, and needs to consider multiple seals of a sealing structure, so that reliability and safety are ensured. (6) The large-opening sealing structure needs higher bearing capacity, bears the functions of external pipeline connection and support, and still has reliable sealing performance under the condition of external bearing.
Combining the above requirements for large opening cryogenic seals for unlined composite tanks, the design of both the seal structure and the seal ring form presents significant challenges.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: the invention provides a large-diameter opening sealing structure suitable for a low-temperature composite material storage tank, which realizes reliable low-temperature sealing after the large-diameter opening of the composite material storage tank, improves the safety and reliability of the composite material storage tank in the use process, and can realize repeated disassembly and assembly.
The technical scheme adopted by the invention is as follows: a large diameter opening seal structure for a cryogenic composite tank comprising: the sealing device comprises a composite plate, a metal flange, a fastening bolt, a sealing cushion block, a graphite sealing ring, a metal rubber composite sealing ring and a hollow metal O-shaped sealing ring;
the composite plate is a part of the composite storage tank, a mounting plane and a sealing surface of the metal flange plate are provided, and a plurality of through holes are formed along the circumferential direction and are used for mounting the fastening bolts;
one surface of the metal flange plate, which is in contact with the composite plate, is provided with a threaded blind hole along the circumferential direction for installing a fastening bolt, and sealing grooves are respectively arranged on the inner ring and the outer ring of a threaded blind hole ring formed by the threaded blind hole for placing a graphite sealing ring;
the metal flange plate is positioned at one side of the composite plate; the sealing cushion blocks are circumferentially distributed on the other side of the composite material plate, and the installation positions correspond to the positions of the through holes in the composite material plate; a metal rubber composite sealing ring is arranged in a sealing groove at the contact side of the sealing cushion block and the composite plate, and a hollow metal O-shaped sealing ring is arranged in a sealing groove at the contact side of the sealing cushion block and the fastening bolt;
the fastening bolts penetrate through the central holes of the sealing cushion blocks and the through holes of the composite material plate, and the end parts of the fastening bolts are installed in the threaded blind holes of the metal flange plates, so that the composite material plate, the metal flange plates and the sealing cushion blocks are fixed.
Further, the basic layering structure of the composite plate adopts layering structure [ +/12/90 [ + ] 2 /±45/90 2 /±75/0] s Wherein + -75 DEG and 0 DEG are adopted for the ultra-thin layering, the thickness of which is 0.08mm, and the plane roughness of the composite plate 1 is required to be Ra0.8, and the flatness is less than 1mm.
Further, the metal flange is manufactured by a metal forging, and the surface roughness requirement of the flange plane at one side provided with the sealing groove is Ra0.8, and the flatness is less than 1mm; under the use condition that the temperature is more than or equal to minus 196 ℃, the metal flange plate is made of aluminum alloy or die steel; under the use condition that the temperature is less than or equal to minus 253 ℃ and less than or equal to minus 196 ℃, the metal flange plate material is manufactured by adopting a steel material of a tile; after the metal flange plate and the composite plate are installed, the installation clearance is required to be smaller than 0.06mm.
Further, the fastening bolt is made of stainless steel or high-temperature alloy material, the surface roughness of the contact surface between the fastening bolt and the sealing cushion block is Ra0.8, and the flatness is less than 1mm; the clearance between the fastening bolt and the sealing cushion block after the installation is smaller than 0.1mm.
Further, the sealing cushion block is made of stainless steel materials and comprises a hexagonal prism section and a cylindrical section; the cylindrical section is a large end, and parallel surfaces for clamping are symmetrically arranged on the side walls; the surface roughness of the sealing surfaces at the two ends of the sealing cushion block is required to be Ra0.8, the flatness is less than 1mm, and the gap between the sealing cushion block and the composite plate is less than 0.1mm after the installation is completed.
Furthermore, the graphite sealing ring is manufactured by graphite die pressing, the cross section of the graphite sealing ring is rectangular, and the specific cross section size is optimally designed according to different using pressures.
Further, the metal rubber composite sealing ring comprises a C-shaped metal framework and a rubber layer coated on the outer surface of the metal framework, and a C-shaped opening of the metal framework faces to the direction of a gas release path in the storage tank.
Further, the hollow metal O-shaped sealing ring comprises a hollow metal ring and pressurized gas therein, the gas pressure is 0.6MPa, the metal ring is made of stainless steel or alloy steel, and the structure of the hollow metal O-shaped sealing ring is adjusted according to the size of the fastening bolt.
A method of installing a large diameter open seal structure suitable for use in a cryogenic composite tank, comprising:
installing a graphite sealing ring into a sealing groove of a metal flange, placing the metal flange in a composite material storage box, moving the metal flange along the central axis of the storage box in the outer direction of the box and gradually approaching to a composite material plate, so that the plane of one side of the metal flange with the sealing groove is in butt joint with the composite material plate, and aligning a threaded blind hole on the metal flange with a through hole on the composite material plate;
placing the metal rubber composite sealing ring into a sealing groove on one side of the contact of the sealing cushion block and the composite plate, and aligning the through holes of the sealing cushion block and the composite plate;
placing the hollow metal O-shaped sealing ring into a sealing groove on one side of the sealing cushion block, which is contacted with the fastening bolt, placing the fastening bolt and pre-tightening the sealing cushion block with a threaded blind hole of the metal flange plate, and fixing and pressing the sealing cushion block by adopting a hexagonal hole tool before pre-tightening the bolt to ensure that the sealing cushion block does not rotate in the pre-tightening process, so that the hollow metal O-shaped sealing ring is in a preliminary pressing state;
after all the fastening bolts and the sealing cushion blocks are pre-tightened in place, gradually applying torque to a set final torque value according to the set torque amplitude of a N m of each stage, measuring the gap between the metal flange and the composite plate after the torque is applied, wherein the measuring position is the middle part of the adjacent fastening bolt, and ensuring that the gap value is not more than 0.06mm; measuring the installation gap between the sealing cushion block and the composite plate, and ensuring that the gap value is not more than 0.1mm; measuring the installation clearance of the sealing surface between the fastening bolt and the sealing cushion block, ensuring that the clearance value is not more than 0.1mm, and finishing the installation of the sealing structure; a is a set value.
Compared with the prior art, the invention has the beneficial effects that:
(1) The invention provides a planar sealing structure with direct contact between a composite material and a metal flange, which adopts simple part combination to form a high-reliability sealing structure capable of being repeatedly disassembled and assembled, and a special sealing cushion block effectively ensures the surface quality of the composite material in the disassembly and assembly process and improves the sealing effect between the composite material and the metal flange in the repeated disassembly and assembly process.
(2) The structure of the invention adopts the principle of double sealing and internal pressure self-tightening sealing, and compensates the problems of the increase of the gap of the sealing surface and the decrease of the pretightening force of the bolt caused by the shrinkage of the metal flange under the condition of the low-temperature internal pressure of the composite material storage tank, thereby having higher sealing safety and reliability.
(3) The sealing structure reasonably utilizes the sealing characteristics of the sealing rings made of different materials, adopts the form of matching a plurality of sealing rings, solves the problems of medium compatibility, low-temperature shrinkage, surface friction, pressure damage and the like of different sealing parts, and ensures the functional coordination of a plurality of sealing parts.
(4) The special sealing cushion block is adopted, and meanwhile, the special sealing cushion block has the functions of relieving the pressure of the composite plate and guaranteeing the sealing, the amplitude of the torque which can be applied by the fastening bolt is enhanced, the reliability of the sealing structure is enhanced, and the problem of local stress concentration of the composite plane is avoided.
(5) The large-diameter opening integral sealing form can ensure that the metal flange plate can still ensure high-reliability sealing when bearing large bending moment and stress, and various pipeline interfaces and bracket structures can be welded on the metal flange plate to form a bearing sealing structure.
Drawings
FIG. 1 is a metal flange structure according to the present invention;
FIG. 2 is a view showing a structure of a fastening bolt according to the present invention;
FIG. 3 is a block diagram illustrating a seal head according to the present invention;
FIG. 4 is a graphite seal ring according to the present invention;
FIG. 5 is a metal rubber composite ring according to the present invention;
FIG. 6 is a hollow metal seal ring according to the present invention;
FIG. 7 is a diagram illustrating a composite panel and metal flange assembly according to the present invention;
FIG. 8 is a view of a composite plate, metal flange, and gasket assembly according to the present invention;
FIG. 9 is a partial view of a large opening diameter flange seal configuration according to the present invention;
fig. 10 is an overall view of a large opening diameter flange seal structure according to the present invention.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings.
Examples:
as shown in fig. 1 to 10, a large diameter opening sealing structure suitable for a low temperature composite material tank includes: the sealing device comprises a composite plate 1, a metal flange 2, a fastening bolt 3, a sealing cushion block 4, a graphite sealing ring 5, a metal rubber composite sealing ring 6 and a hollow metal O-shaped sealing ring 7.
The design idea of the large-diameter opening sealing structure of the low-temperature composite material storage tank is as follows:
sealing principle: the basic sealing principle utilizes the structural form of a sealing groove and a sealing ring, adopts the form of installation in the metal flange 2, and utilizes the self-compaction effect of the internal pressure of the box body on the sealing surface to counteract the problem of relaxation of the compaction force of the sealing surface caused by shrinkage of the metal flange 2 at low temperature. The sealing ring adopts the graphite sealing ring 5 with extremely low thermal expansion coefficient and good elasticity at low temperature, so that the problems of low-temperature shrinkage and embrittlement of the conventional rubber sealing ring are avoided. The special sealing cushion block 4 is adopted between the fastening bolt 3 and the composite material, the stress concentration effect of the pretightening force of the bolt on the surface of the composite material is dispersed, and the sealing groove structure of the special sealing cushion block can also realize the second sealing outside the sealing between the metal flange 2 and the composite material plate 1. The whole sealing structure realizes double-channel high-reliability sealing.
Composite plate 1: the composite plate 1 is used as a part of a composite storage tank to provide a mounting plane and a sealing surface of the metal flange 2, and the basic layering structure adopts a specific optimized layering structure [ +/12/90 [ + ] 2 /±45/90 2 /±75/0] s The total thickness of the composite material is about 10mm, the thickness of a conventional paving layer is about 0.12mm, wherein ultra-thin paving layers with the thickness of about 0.08mm are adopted for the paving layers with the angles of +/-75 degrees and 0 degrees so as to adapt to the stress condition and the anti-leakage performance requirement of the composite material storage tank under the internal pressure condition, the plane thermal expansion coefficient of the paving layer structure under the low temperature is uniform, the stress distribution under the internal pressure condition is uniform, the phenomenon of local stress concentration of an opening can not occur, the interlayer bonding strength of the composite material plate is enhanced by the addition of the ultra-thin paving layer structure, the interlayer delamination resistance capability of the composite material plate under the low temperature condition is enhanced, and the interlayer defect of the composite material plate under the compression stress of a bolt is ensured. The total thickness of the composite plate is about 10mm, the plane roughness requirement Ra0.8 is less than 1mm, the planeness is less than 1mm, the opening diameter is more than 400mm, 48 through holes with phi 11mm are formed in the opening diameter, and the through holes are used for connecting the fastening bolts 3 with the metal flange plate 2 through the composite plate 1.
As shown in fig. 1, the metal flange 2: the metal flange plate 2 is manufactured by a metal forging piece, and a threaded blind hole is formed in the surface of the metal flange plate, which is contacted with the composite plate 1, for connecting the fastening bolt 3. The inner ring and the outer ring of the threaded blind hole ring formed by butt joint of the threaded blind holes are provided with 2 sealing grooves for placing sealing rings, the surface roughness of the side, provided with the sealing grooves, of the metal flange plate 2 is required to be Ra0.8, the flatness is less than 1mm, and the thickness of the flange is 22mm. Under the use condition that the temperature is more than or equal to minus 196 ℃, the material of the metal flange plate 2 can be conventional materials such as aluminum alloy, die steel and the like; the metal flange 2 is manufactured by adopting a inconel steel material under the use condition that the temperature is minus 253 ℃ to minus 196 ℃. The metal flange 2 is installed from the inside to the outside of the composite material storage tank, and after the metal flange 2 and the composite material plate 1 are installed, the installation clearance is required to be smaller than 0.06mm.
As shown in fig. 2, the fastening bolt 3: the fastening bolt 3 is made of stainless steel or high-temperature alloy materials, and unlike a common standard bolt, the contact surface of the fastening bolt 3 and the sealing cushion block 4 needs to be processed, so that the surface roughness Ra0.8 of the fastening bolt is guaranteed, the flatness is smaller than 1mm, the fastening bolt 3 and the sealing cushion block 4 are sealed by adopting a small-diameter sealing ring, and the sealing ring adopts a hollow metal O-shaped sealing ring 7 for resisting friction generated in the rotating and fastening process of the bolt and guaranteeing reliable sealing after the bolt is screwed. The torque applied by the bolts is required to be 30+/-3 N.m, and the gap between the fastening bolts 3 and the sealing cushion blocks 4 after the installation is completed is smaller than 0.1mm.
As shown in fig. 3, the seal cushion block 4: the sealing cushion block 4 is made of stainless steel materials and comprises a hexagonal prism section and a cylindrical section; the cylindrical section is a large end, parallel surfaces for clamping are symmetrically arranged on the side wall, the diameter of a central through hole of the sealing cushion block 4 is consistent with that of a through hole of the composite material plate 1, one surface of the sealing cushion block is contacted with the plane of the composite material plate 1, the other surface of the sealing cushion block is contacted with the fastening bolt 3, sealing grooves are arranged on the two contact surfaces for installing sealing rings, and the sealing ring contacted with the composite material plate 1 adopts a metal framework and a metal rubber composite sealing ring 6 of a rubber skin; the sealing ring contacting with the fastening bolt 3 adopts a hollow metal O-shaped sealing ring 7, the surface roughness requirement Ra0.8 of two sealing surfaces of the sealing cushion block 4 is less than 1mm in flatness, and the gap between the sealing cushion block 4 and the composite plate 1 after installation is less than 0.1mm. The contact surface between the fastening bolt and the composite plate 1 is large, so that the pressure generated by the moment applied by the fastening bolt 3 to the composite plate 1 can be relieved, and the compression damage of the local concentrated force to the resin layer of the composite plate 1 is prevented. The hexagonal shape of the sealing cushion block 4 is fixed by adopting a fixture when the fastener is installed, so that when the fastening bolt 3 is screwed up, the mutual sliding between the sealing cushion block 4 and the composite plate 1 is avoided, and the relative sliding can scratch the resin layer on the surface of the composite plate 1, which is not beneficial to repeated disassembly and assembly of the sealing structure.
As shown in fig. 4, the graphite seal ring 5: the graphite sealing ring 5 is made of graphite by die pressing, the cross section is rectangular, the specific cross section size is optimally designed according to different using pressures, the graphite sealing ring has the advantages of low expansion coefficient at low temperature, good elastic modulus retention, stable chemical property and the like, the problem of embrittlement and rebound reduction of rubber materials can not occur under the low temperature condition, the surface hardness is slightly lower than that of carbon fiber composite materials, and the surface state of the composite materials can not be damaged in the compaction deformation process.
As shown in fig. 5, the metal rubber composite seal ring 6: the metal rubber composite ring 6 comprises a C-shaped metal framework and a rubber layer with a certain thickness coated on the outer surface of the C-shaped metal framework, the metal framework is generally made of low expansion coefficient alloy, a C-shaped opening faces to the direction of a gas release path in the box, and the C-shaped opening has a self-sealing effect of opening under the action of gas pressure in the box to enlarge the contact area of the sealing ring and the sealing surface. The rubber layer can relieve the pressure centralization effect of the sealing ring on the surface of the composite material, the supporting effect of the metal framework can make up the defect of the rubber modulus reduction at low temperature, the sealing ring is positioned between the composite material plate 1 and the sealing cushion block 4 and is not in direct contact with medium in the box, the temperature condition is good, the medium compatibility requirement is low, and the metal rubber composite sealing ring 6 can well play a role in sealing and simultaneously reduce the production cost.
As shown in fig. 6, hollow metal O-ring 7: the hollow metal O-shaped sealing ring 7 consists of a hollow metal ring with a certain thickness and pressurized gas therein, the gas pressure is 0.6MPa, the metal ring material is generally metal material with higher hardness such as stainless steel, alloy steel and the like, the surface rigidity is higher, the rebound modulus is high, the hollow metal O-shaped sealing ring is wear-resistant, the sealing ring can also ensure higher sealing effect in the process of applying moment to the fastening bolt 3, the surface layer of the sealing ring can not be worn and damaged under the friction effect to reduce the sealing effect, and the structure of the hollow metal O-shaped sealing ring 7 can be flexibly adjusted according to the size of the bolt.
The method for installing the large-diameter opening sealing structure suitable for the low-temperature composite material storage tank comprises the following steps:
first, the graphite sealing ring 5 is installed in the sealing groove of the metal flange plate 2, the metal flange plate 2 is placed in the composite material storage box, the metal flange plate 2 moves along the central axis of the storage box in the outer direction of the box and gradually approaches to the composite material plate 1, and the plane of one side of the metal flange plate 2 with the sealing groove is aligned with the butt joint hole of the composite material plate 1, so that the combined structure of the metal flange plate and the composite material plate is formed as shown in fig. 7.
And secondly, placing the composite sealing ring 6 of the metal framework and the rubber skin into a sealing groove on one side of the contact of the sealing cushion block 4 and the composite plate 1, and aligning through holes of the sealing cushion block 4 and the composite plate 1 to form a combined structure of the metal flange plate 2 and the composite plate 1 and the sealing cushion block 4 shown in fig. 8.
Thirdly, placing the hollow metal O-shaped sealing ring 7 into a sealing groove at the upper end of the sealing cushion block 4, placing the fastening bolt 3 and pre-tightening the fastening bolt with a threaded blind hole of the metal flange plate 2, fixing and pressing the sealing cushion block 4 by adopting a hexagonal hole tool before pre-tightening the fastening bolt, ensuring that the sealing cushion block 4 does not rotate in the pre-tightening process, and enabling the hollow metal O-shaped sealing ring 7 to be in a preliminary pressing state to form a combined structure of the metal flange plate 2+composite material plate 1+the sealing cushion block 4+the fastening bolt 3 as shown in fig. 9.
And fourthly, after the 48 fastening bolts 3 and the sealing cushion blocks 4 are pre-tightened in place, gradually applying the moment amplitude of 5 N.m of each stage according to the circle, gradually applying the moment amplitude of 5 N.m to 30 N.m, measuring the gap between the metal flange plate 2 and the composite plate 1 after the moment is applied, wherein the measuring position is the middle part adjacent to the fastening bolts 3, uniformly measuring 24 positions, and ensuring that the gap value is not more than 0.06mm. And the installation clearance between the sealing cushion block 4 and the composite plate 1 is measured, and the fastening bolts 3 at 48 positions are all required to be measured, so that the clearance value is not more than 0.1mm. And measuring the installation clearance of the sealing surface between the fastening bolt 3 and the sealing cushion block 4, and ensuring that the clearance value is not more than 0.1mm, thus completing the installation of the sealing structure shown in FIG. 10.
When the metal flange needs to be disassembled, the sealing cushion block 4 is fixed by adopting the hexagonal hole tool, the fastening bolts 3 are unscrewed step by step, before the fastening bolts 3 are completely screwed out of the metal flange 2, the metal flange 2 is required to be fixed by an external tool, the flange 2 is prevented from falling off and injuring the box body by smashing, the sealing cushion block 4 is disassembled after all the fastening bolts 3 are taken out, the plane state of the composite plate 1 is inspected, the reinstallation of the sealing structure can be completed according to the installation flow after the plane state is good, and all sealing elements need to be replaced.
The invention, in part not described in detail, is within the skill of those skilled in the art.
Claims (8)
1. A large diameter opening sealing structure adapted for use in a cryogenic composite tank, comprising: the sealing device comprises a composite plate (1), a metal flange plate (2), a fastening bolt (3), a sealing cushion block (4), a graphite sealing ring (5), a metal rubber composite sealing ring (6) and a hollow metal O-shaped sealing ring (7);
the composite plate (1) is a part of a composite storage box, a mounting plane and a sealing surface of the metal flange plate (2) are provided, and a plurality of through holes are formed along the circumferential direction and are used for mounting fastening bolts (3);
one surface of the metal flange plate (2) contacted with the composite plate (1) is provided with a threaded blind hole along the circumferential direction for installing a fastening bolt (3), and the inner and outer rings of the threaded blind hole ring formed by the threaded blind hole are respectively provided with a sealing groove for placing a graphite sealing ring (5);
the metal flange plate (2) is positioned at one side of the composite plate (1); the sealing cushion blocks (4) are circumferentially distributed on the other side of the composite material plate (1), and the installation positions correspond to the positions of the through holes in the composite material plate (1); a metal rubber composite sealing ring (6) is arranged in a sealing groove at the contact side of the sealing cushion block (4) and the composite plate (1), and a hollow metal O-shaped sealing ring (7) is arranged in a sealing groove at the contact side of the sealing cushion block and the fastening bolt (3);
the fastening bolts (3) penetrate through the central holes of the sealing cushion blocks (4) and the through holes of the composite material plate (1), and the end parts of the fastening bolts are arranged in threaded blind holes of the metal flange plate (2) so as to fix the composite material plate (1), the metal flange plate (2) and the sealing cushion blocks (4);
the basic layering structure of the composite plate (1) adopts a layering structure
[±12/90 2 /±45/90 2 /±75/0] s Wherein ultra-thin layering with the thickness of 0.08mm is adopted for layering at +/-75 degrees and 0 degrees, the plane roughness of the composite plate (1) is required to be Ra0.8, and the flatness is less than 1mm;
the sealing cushion block (4) is made of stainless steel and comprises a hexagonal prism section and a cylindrical section; the cylindrical section is a large end, and parallel surfaces for clamping are symmetrically arranged on the side walls; the surface roughness of the sealing surfaces at two ends of the sealing cushion block (4) is required to be Ra0.8, the flatness is less than 1mm, and the gap between the sealing cushion block (4) and the composite plate (1) after the installation is completed is less than 0.1mm.
2. The large-diameter opening sealing structure suitable for the low-temperature composite material storage tank according to claim 1, wherein the metal flange plate (2) is manufactured by a metal forging piece, and the surface roughness requirement of a flange plane on one side provided with a sealing groove is Ra0.8, and the flatness is less than 1mm; under the use condition that the temperature is more than or equal to minus 196 ℃, the material of the metal flange plate (2) is aluminum alloy or die steel; under the use condition that the temperature is less than or equal to minus 253 ℃ and less than or equal to minus 196 ℃, the metal flange plate (2) material is manufactured by adopting a inconel steel material; after the metal flange plate (2) and the composite plate (1) are installed, the installation clearance is required to be smaller than 0.06mm.
3. The large-diameter opening sealing structure suitable for the low-temperature composite material storage tank according to claim 1, wherein the fastening bolt (3) is made of stainless steel or high-temperature alloy material, and the surface roughness of the contact surface of the fastening bolt and the sealing cushion block (4) is Ra0.8, and the flatness is less than 1mm; the clearance between the fastening bolt (3) and the sealing cushion block (4) after the installation is smaller than 0.1mm.
4. The large-diameter opening sealing structure suitable for the low-temperature composite material storage tank according to claim 1, wherein the graphite sealing ring (5) is manufactured by graphite die pressing, the cross section is rectangular, and the specific cross section size is optimally designed according to different using pressures.
5. The large-diameter opening sealing structure suitable for the low-temperature composite material storage tank according to claim 1, wherein the metal rubber composite sealing ring (6) comprises a C-shaped metal framework and a rubber layer coated on the outer surface of the metal framework, and the C-shaped opening of the metal framework faces to the direction of a gas discharge path in the storage tank.
6. A large diameter opening sealing structure suitable for a low temperature composite material storage tank according to claim 1, characterized in that the hollow metal O-ring (7) comprises a hollow metal ring and gas pressurized therein, the gas pressure is 0.6MPa, the metal ring material is stainless steel or alloy steel, and the structure of the hollow metal O-ring (7) is adjusted according to the size of the fastening bolt (3).
7. A method of installing a large diameter open seal structure suitable for a cryogenic composite tank, comprising:
installing a graphite sealing ring (5) into a sealing groove of a metal flange plate (2), placing the metal flange plate (2) inside a composite material storage tank, moving the metal flange plate (2) along the central axial direction of the storage tank towards the outside of the tank, gradually approaching to a composite material plate (1), enabling a plane on one side of the metal flange plate (2) with the sealing groove to be in butt joint with the composite material plate (1), and aligning threaded blind holes on the metal flange plate (2) with through holes on the composite material plate (1);
placing a metal rubber composite sealing ring (6) into a sealing groove on one side of the sealing cushion block (4) contacted with the composite material plate (1), and aligning through holes of the sealing cushion block (4) and the composite material plate (1);
placing a hollow metal O-shaped sealing ring (7) into a sealing groove on one side of a sealing cushion block (4) contacted with a fastening bolt (3), placing the fastening bolt (3) and pre-tightening a threaded blind hole of a metal flange plate (2), and fixing and pressing the sealing cushion block (4) by adopting a hexagonal hole tool before pre-tightening the bolt to ensure that the sealing cushion block (4) does not rotate in the pre-tightening process, so that the hollow metal O-shaped sealing ring (7) is in a preliminary pressing state;
after all the fastening bolts (3) and the sealing cushion blocks (4) are pre-tightened in place, moment is applied to a set final moment value step by step according to a set moment amplitude of a N m of each stage, and the sealing structure is installed.
8. The method of installing a large diameter opening seal structure for a cryogenic composite tank of claim 7, wherein said applying moment in circles according to a set moment amplitude per stage a N-m to a set final moment value, further comprises: after the moment is applied, measuring the gap between the metal flange plate (2) and the composite plate (1), wherein the measuring position is the middle part of the adjacent fastening bolt (3), and the gap value is not more than 0.06mm; measuring the installation gap between the sealing cushion block (4) and the composite plate (1), and ensuring that the gap value is not more than 0.1mm; and measuring the installation clearance of the sealing surface between the fastening bolt (3) and the sealing cushion block (4), and ensuring that the clearance value is not more than 0.1mm.
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| CN202210617853.4A CN115127020B (en) | 2022-06-01 | 2022-06-01 | Large-diameter opening sealing structure suitable for low-temperature composite material storage tank |
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| US6361055B1 (en) * | 1999-08-23 | 2002-03-26 | Northrop Grumman Corporation | Cryogenic composite tank seals |
| JP2005214369A (en) * | 2004-02-02 | 2005-08-11 | Uchiyama Mfg Corp | Sealing structure of gasket |
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| CN114163970A (en) * | 2021-12-23 | 2022-03-11 | 山东北方现代化学工业有限公司 | High-strength anti-aging single-component modified sealant for bonding rubber and plastic composite materials and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US7854434B2 (en) * | 2007-04-12 | 2010-12-21 | Ti Group Automotive Systems, L.L.C. | Ring seal with axially-opposed radially-offset seal beads |
| US11193588B2 (en) * | 2017-08-09 | 2021-12-07 | Mainspring Energy, Inc. | Reinforced sealing rings |
| US10830355B2 (en) * | 2019-01-07 | 2020-11-10 | GM Global Technology Operations LLC | Rubber coated metal seal with integrated inner seal and outer seal portions |
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| US6361055B1 (en) * | 1999-08-23 | 2002-03-26 | Northrop Grumman Corporation | Cryogenic composite tank seals |
| JP2005214369A (en) * | 2004-02-02 | 2005-08-11 | Uchiyama Mfg Corp | Sealing structure of gasket |
| JP5198676B1 (en) * | 2012-06-27 | 2013-05-15 | 卓男 水木 | Pressure vessel joint structure and piping joint structure |
| CN103075587A (en) * | 2013-01-17 | 2013-05-01 | 中国科学院上海应用物理研究所 | Dual-sealing flange |
| KR101506190B1 (en) * | 2013-10-30 | 2015-03-25 | 제일 이엔에스 주식회사 | An insulated gasket for high temperature and pressure having metal o ring |
| CN114163970A (en) * | 2021-12-23 | 2022-03-11 | 山东北方现代化学工业有限公司 | High-strength anti-aging single-component modified sealant for bonding rubber and plastic composite materials and preparation method thereof |
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| CN115127020A (en) | 2022-09-30 |
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