CN116242553A - Preparation method and test method of leakage sample of high-pressure gas cylinder - Google Patents
Preparation method and test method of leakage sample of high-pressure gas cylinder Download PDFInfo
- Publication number
- CN116242553A CN116242553A CN202310298940.2A CN202310298940A CN116242553A CN 116242553 A CN116242553 A CN 116242553A CN 202310298940 A CN202310298940 A CN 202310298940A CN 116242553 A CN116242553 A CN 116242553A
- Authority
- CN
- China
- Prior art keywords
- coating layer
- sample
- carbon fiber
- leakage
- clamp
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000002360 preparation method Methods 0.000 title claims abstract description 14
- 238000010998 test method Methods 0.000 title claims abstract description 7
- 239000011247 coating layer Substances 0.000 claims abstract description 151
- 229920000049 Carbon (fiber) Polymers 0.000 claims abstract description 73
- 239000004917 carbon fiber Substances 0.000 claims abstract description 73
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 72
- 238000000034 method Methods 0.000 claims abstract description 64
- 238000012360 testing method Methods 0.000 claims abstract description 62
- 239000001307 helium Substances 0.000 claims abstract description 40
- 229910052734 helium Inorganic materials 0.000 claims abstract description 40
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims abstract description 40
- 239000007789 gas Substances 0.000 claims abstract description 38
- 238000001514 detection method Methods 0.000 claims abstract description 20
- 238000007789 sealing Methods 0.000 claims abstract description 16
- 238000010438 heat treatment Methods 0.000 claims description 35
- 239000010410 layer Substances 0.000 claims description 31
- 238000004804 winding Methods 0.000 claims description 24
- 239000003292 glue Substances 0.000 claims description 23
- 239000007788 liquid Substances 0.000 claims description 17
- 239000011248 coating agent Substances 0.000 claims description 16
- 238000000576 coating method Methods 0.000 claims description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 14
- 239000002184 metal Substances 0.000 claims description 13
- 238000000748 compression moulding Methods 0.000 claims description 12
- 239000002131 composite material Substances 0.000 claims description 10
- 238000005520 cutting process Methods 0.000 claims description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 7
- 239000001257 hydrogen Substances 0.000 claims description 7
- 229910052739 hydrogen Inorganic materials 0.000 claims description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims description 7
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 6
- 238000003756 stirring Methods 0.000 claims description 6
- 230000000149 penetrating effect Effects 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 3
- 238000001819 mass spectrum Methods 0.000 claims description 3
- 238000004321 preservation Methods 0.000 claims description 3
- 239000000495 cryogel Substances 0.000 claims description 2
- 238000005253 cladding Methods 0.000 description 15
- 239000000565 sealant Substances 0.000 description 4
- 238000011161 development Methods 0.000 description 3
- 230000018109 developmental process Effects 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 238000007781 pre-processing Methods 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 239000004820 Pressure-sensitive adhesive Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 230000011218 segmentation Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
- G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
- G01M3/202—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material using mass spectrometer detection systems
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
- G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
- G01M3/22—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators
- G01M3/226—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators for containers, e.g. radiators
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/32—Hydrogen storage
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Examining Or Testing Airtightness (AREA)
Abstract
The invention provides a preparation method and a testing method of a high-pressure gas cylinder leakage sample. The test method comprises the following steps: providing a leakage sample and a detection device for leakage performance detection; installing the leakage sample in the groove of the first clamp, wherein the carbon fiber sample and the first coating layer are contained in the groove, and the second coating layer is embedded in the first channel or the second channel; after all parts of the detection device are connected, testing the leakage condition of the leakage sample according to a preset testing process, and acquiring an indication value of the helium mass spectrometer leak detector. The invention solves the technical problem of inconvenient sealing caused by thickness difference by embedding the second coating layer with the outer diameter different from the first coating layer into the helium inlet or the helium outlet, and has the advantages of convenient test and high test accuracy.
Description
Technical Field
The invention belongs to the technical field of high-pressure gas cylinder leakage test, and particularly relates to a preparation method and a test method of a high-pressure gas cylinder leakage sample.
Background
With the rapid development of aerospace technology, aerospace vehicles need to perform heavy and complex aerospace tasks. At present, most of aircrafts in an aerospace system, such as an artificial satellite, an aerospace plane, a carrier rocket and a space station, need a large number of pressure containers for storing various liquids or gases so as to maintain the normal operation of a subsystem, and development of high-performance high-pressure gas cylinders is important for long-term in-orbit flight of the aerospace craft.
Gas cylinders can be divided into two main categories according to application and structure: metal cylinders and composite cylinders. At present, when a composite gas cylinder works in a liquid hydrogen environment and a liquid oxygen environment, the problems of permeability and liquid oxygen compatibility are required to be solved. The related art adopts the composite construction of metal inside lining + composite material layer + metal coating layer to solve this technical problem, specifically, because high-pressure gas cylinder is including being located the stack shell at middle part, divide to locate seal bottom and head at stack shell both ends, and with the bottleneck that the head is connected, when carrying out the cladding of metal coating layer, adopts the mode of segmentation cladding, the junction of stack shell and seal bottom, the junction of stack shell and head and the junction of head and bottleneck all need set up overlap joint portion. The existence of the lap joint portion causes a difference in thickness on the surface of the sample, and it is difficult to seal the leakage sample.
The patent application number is CN202111441863.9, the largest strain position of the loaded pure composite pressure container is measured by using a distributed optical fiber sensor, the leakage rate of the position is measured, and the strain-leakage association rule of the composite pressure container is established by linear interpolation, cubic B-spline interpolation, a least square method and the like.
Disclosure of Invention
The invention aims to provide a preparation method and a testing method of a leakage sample with a lap joint part, which are used for solving the technical problem of inconvenient sealing caused by thickness difference by embedding a second coating layer with an outer diameter different from that of a first coating layer into a helium inlet or a helium outlet, and have the advantages of convenience in testing and high testing accuracy.
In order to achieve the above object, the present invention provides a method for preparing a leakage sample of a high pressure gas cylinder having a lap joint portion, the high pressure gas cylinder being used in a liquid oxygen environment or a liquid hydrogen environment, a housing wall of the high pressure gas cylinder having a multi-layered structure, and an outermost metal layer including a body portion just covering a sub-outer metal layer or a composite material layer, and a body lap joint portion extending from the body portion, the method comprising the steps of:
(1) Preparing a carbon fiber coating layer according to a preset compression molding process, and cutting the carbon fiber coating layer into a round carbon fiber sample with a preset diameter;
(2) Providing a first concentric annular coating layer and a second coating layer, wherein the second coating layer is used for covering a central through hole of the first coating layer, the outer diameter of the first coating layer is the same as the preset diameter of the carbon fiber sample, and the diameter of the second coating layer is larger than the inner diameter of the first coating layer and smaller than the outer diameter of the first coating layer;
(3) Coating pretreated DW-3 low-temperature glue on the upper surface and the lower surface of the first coating layer respectively, and connecting the first coating layer with the carbon fiber sample and the second coating layer respectively to obtain a leakage sample to be solidified, wherein the first coating layer is clamped between the carbon fiber sample and the second coating layer, the second coating layer is covered on the central through hole, the central axis of the carbon fiber sample, the central axis of the first coating layer and the central axis of the second coating layer are all positioned on the same straight line, and the connecting part of the first coating layer and the second coating layer is a sample lap joint part;
(4) And sealing the leakage sample to be cured, and then placing the sealed leakage sample into an autoclave, and curing according to a preset curing process to obtain the leakage sample.
In a specific embodiment, the preset compression molding process includes: heating to 90 ℃ from room temperature at a heating rate of 1.5 ℃/min, preserving heat for 1h, heating to 120 ℃ at a heating rate of 1.5 ℃/min, preserving heat for 2h, heating to 150 at a heating rate of 1.5 ℃/min, preserving heat for 3h, and finally naturally cooling.
In a specific embodiment, the preset curing process includes: the temperature is raised to 40-55 ℃ from room temperature at the heating rate of 1.5 ℃/min, the pressure in the autoclave is raised to 0.05-0.1MPa at the boosting rate of 0.02Mpa/min, the temperature is kept for 7-9h, and the vacuum bag wrapping the leakage sample to be solidified is vacuumized at 0.1Mpa in the whole process.
In a specific embodiment, the pretreatment of the DW-3 cryogel comprises a defoaming process and a heating treatment process which are sequentially carried out.
In a specific embodiment, the defoaming process is performed in a vacuum stirring defoaming machine, the defoaming process comprises a fourth stage which is sequentially performed, and in the first stage, the rotating speed of the stirring machine is 0r/min, and the vacuum degree in the defoaming machine is 30Kpa; in the second stage, the rotating speed of the stirrer is 500r/min, and the vacuum degree in the deaeration machine is 7-9Kpa; in the third stage, the revolution of the stirrer is 1900-2100r/min, and the vacuum degree in the deaerating machine is 3-5Kpa; in the fourth stage, the revolution of the stirrer is 450-600r/min, and the vacuum degree in the deaeration machine is 30Kpa.
In a specific embodiment, the time corresponding to the first stage is 0 to 10s, the time corresponding to the second stage is 11 to 25s, the time corresponding to the third stage is 26 to 115s, and the time corresponding to the fourth stage is 116 to 125s.
In a specific embodiment, the parameters of the heat treatment process are: the heating temperature is 60-70℃: the heat preservation time is 50-70 min.
In a specific embodiment, the step (1) includes the steps of:
providing a flat template, and winding carbon fiber yarns immersed in a glue groove on the flat template according to a preset winding process to obtain a carbon fiber coating layer to be solidified;
providing a forming die for compression molding, wherein the forming die comprises an upper die and a lower die which are identical in structure, and the upper die and the lower die comprise a die body, a protruding part extending from the die body and a plurality of screw holes respectively formed in two sides of the die body;
clamping the carbon fiber coating layer to be solidified between the protruding part of the upper die and the protruding part of the lower die, and locking the upper die and the lower die through bolts to obtain a closed forming die;
placing the closed forming die in a heating furnace, and curing the carbon fiber filaments according to the preset compression molding process to obtain a carbon fiber coating;
cutting the carbon fiber coating layer into a round carbon fiber sample with a preset diameter.
The invention provides a leakage sample, which is prepared by adopting the preparation method, and comprises a first coating layer, a carbon fiber sample and a second coating layer, wherein the carbon fiber sample and the second coating layer are respectively arranged on two sides of the first coating layer and are connected with the first coating layer through DW-3 low-temperature glue, the first coating layer is of a concentric annular structure, the second coating layer is covered on a central through hole of the first coating layer, and the central axis of the first coating layer, the central axis of the carbon fiber sample and the central axis of the second coating layer are all positioned on the same straight line.
The invention also provides a test method of the leakage test sample, which comprises the following steps:
providing a leakage sample and a detection device for leakage performance detection; wherein,,
the leakage test sample is the leakage test sample described above;
the detection device comprises a test clamp, wherein the test clamp comprises a first clamp and a second clamp which are oppositely arranged, the first clamp comprises a first clamp main body part, a first extension part extending from the middle part of the first clamp main body part to a direction far away from the second clamp, a groove formed by inwards sinking from the surface of the first clamp main body part towards the second clamp, and a first channel formed by penetrating through the first extension part and the bottom of the groove along a first direction; the second clamp comprises a second clamp main body part, a second extension part extending from the middle part of the second clamp main body part to a direction far away from the first clamp, a boss extending from the second clamp main body part to a direction of the first clamp, and a second channel penetrating through the second extension part and the boss along the first direction, wherein the shape of the boss is matched with that of the groove; the detection device further comprises a low-temperature box for accommodating the test fixture, a liquid nitrogen tank communicated with the low-temperature box, a helium tank communicated with the first channel of the test fixture through a helium pipeline, a vacuum pump communicated with the helium pipeline through a first connecting pipeline, a pressure gauge arranged at one end of the helium pipeline close to the helium tank, and a helium mass spectrum leak detector communicated with the second channel of the test fixture through a second connecting pipeline;
installing the leakage sample in the groove of the first clamp, wherein the carbon fiber sample and the first coating layer are contained in the groove, and the second coating layer is embedded in the first channel or the second channel;
after all parts of the detection device are connected, testing the leakage condition of the leakage sample according to a preset testing process, and acquiring an indication value of the helium mass spectrometer leak detector.
The beneficial effects of the invention at least comprise:
1. according to the invention, the leakage rate of the curvature cementing structure sample is simplified into a flat sample for evaluation, a specific preparation method is adopted to prepare the leakage sample, so that the leakage sample can resist the low temperature of a liquid nitrogen environment and a liquid hydrogen environment, when the leakage sample is tested, the second coating layer comprising the lap joint part is embedded into the first channel or the second channel, and the carbon fiber sample and the first coating layer are accommodated in the groove, so that the problem that the leakage sample is difficult to seal due to the thickness difference on the surface of the sample of the leakage sample is solved.
2. According to the preparation method of the leakage sample adopted by the invention, the viscosity of the glue can be improved by preprocessing the DW-3 low-temperature glue, so that the glue can be smeared uniformly; the preset curing process is adopted for curing, so that on one hand, DW-3 low-temperature glue at the temperature of-196 ℃ can be ensured not to be spread, the test of the leakage rate can not be influenced, and on the other hand, the glue joint position can be ensured to have high strength under the low-temperature condition, and the pressure applied in the test process can be borne.
In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. The present invention will be described in further detail with reference to the drawings.
Drawings
FIG. 1 is a partial block diagram of a high pressure gas cylinder with a lap joint according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart of a method for preparing a leakage sample of a high-pressure gas cylinder with a lap joint according to an embodiment of the present invention;
FIG. 3 is a schematic view of a leak test piece according to an embodiment of the present invention;
FIG. 4 is a flow chart illustrating steps of a method for testing a leakage specimen according to an embodiment of the present invention;
FIG. 5 is a block diagram showing the connection of a detection device for leak performance detection according to an embodiment of the present invention;
fig. 6 is a schematic view of an angle of a test fixture of the inspection apparatus shown in fig. 5.
Reference numerals illustrate:
| |
211 | |
212 | |
213 |
| |
214 | |
221 | |
2211 |
| Gas |
2212 | |
300 | |
310 |
| Center through |
311 | |
320 | |
330 |
| |
331 | Sample lap |
332 | |
100 |
| |
10 | First clamp | 11 | A first clamp main body part | 111 |
| |
112 | Groove | 113 | A first channel | 114 |
| |
12 | Second clamp body part | 121 | |
122 |
| |
123 | |
124 | |
20 |
| |
30 | |
40 | |
50 |
| |
60 | Helium mass |
70 | |
91 |
| First connecting |
92 | Second connecting |
93 |
Detailed Description
The embodiments of the invention are described in detail below with reference to the attached drawings, but the invention can be defined and covered in a number of different embodiments according to the claims.
With the rapid development of aerospace technology, aerospace vehicles need to perform heavy and complex aerospace tasks. Currently, most of aircrafts in an aerospace system, such as an artificial satellite, an aerospace plane, a carrier rocket and a space station, need a large number of pressure containers to store various liquids or gases for maintaining the normal operation of a subsystem, and a high-pressure gas cylinder is used as a container for storing various liquids and gases and needs to be used in a liquid oxygen environment or a liquid hydrogen environment, so that after the high-pressure gas cylinder is manufactured, the leakage performance of the high-pressure gas cylinder needs to be tested in a low-temperature environment.
When the overlap joint portion exists in the high-pressure gas cylinder, because the sample surface has thickness difference, be difficult to carry out the sealing of seepage sample, prior art needs to carry out the reconstruction of meeting an emergency to the high-pressure gas cylinder to paste a plurality of distributed optical fiber sensor and temperature sensor and detect, data processing is comparatively loaded down with trivial details, and can't effectively survey the seepage performance of cementing department.
Referring to fig. 1, the structure of the high pressure gas cylinder with the lap joint part is as follows: the high-pressure gas cylinder comprises a cylinder body 211 positioned in the middle, a bottom seal 212, a sealing head 213 and a bottle mouth 214 connected with the sealing head 213, wherein the bottom seal 212 and the sealing head 213 are respectively arranged at two ends of the cylinder body 211, the wall of the casing of the high-pressure gas cylinder is of a multi-layer structure, the metal layer 221 positioned at the outermost side comprises a body portion 2211 just coating the metal layer or the composite material layer at the secondary outer side, and a plurality of cylinder body lap joint portions 2212 extending from the body portion 2211, the number of the cylinder body lap joint portions is multiple, and the cylinder body lap joint portions are respectively arranged at the connection positions of the cylinder body 211 and the bottom seal 212 and the sealing head 213.
The above only describes a structure of the high-pressure gas cylinder to facilitate understanding of the structure that the related art high-pressure gas cylinder has the overlap portion, in other embodiments, the overlap portion may be disposed at a connection portion between the sealing head and the bottle mouth, etc., which is not limited in the present invention, and the present invention is limited in that the high-pressure gas cylinder has the structure feature of the overlap portion, which has the defect of inconvenient sealing, so that it is complex and inconvenient to test the leakage rate of the glued portion. In order to solve the technical problems, the invention provides a test method suitable for the leakage rate test of the high-pressure gas cylinder and a preparation method of a leakage sample.
Referring to fig. 2, the present invention provides a method for preparing a leakage sample of a high-pressure gas cylinder with a lap joint, wherein the high-pressure gas cylinder is used in a liquid oxygen environment or a liquid hydrogen environment, a housing wall of the high-pressure gas cylinder has a multi-layer structure, an outermost metal layer comprises a body part just covering a sub-outer metal layer or a composite material layer, and a cylinder lap joint part extending from the body part, and the method for preparing the leakage sample comprises the following steps:
s11, preparing a carbon fiber coating layer according to a preset compression molding process, and cutting the carbon fiber coating layer into a round carbon fiber sample with a preset diameter;
the method specifically comprises the following steps:
step (1) providing a flat template, and winding carbon fiber wires immersed in a glue groove on the flat template according to a preset winding process to obtain a carbon fiber coating layer to be solidified;
in this embodiment, the flat template is rectangular.
In the embodiment, the carbon fiber filaments are T700SC-12k, and the carbon fiber filaments are C601G resin placed in a glue tank.
Preferably, the predetermined winding process includes: the winding angles of the carbon fibers were controlled to be + -89 deg., + -12 deg., + -89 deg., + -25 deg., + -89 deg., + -32 deg., + -89 deg., + -42 deg., 89 deg., using an automatic winding apparatus.
The winding angle is specifically described, namely, first round circumferential winding is carried out according to +/-89 degrees, then second round longitudinal winding is carried out according to +/-12 degrees, 9 rounds of winding is carried out according to the angle according to … …, and after the winding is completed, 18 layers of carbon fiber yarns are wound on the flat template.
It should be noted that, winding of ±89° belongs to circumferential winding, and winding of other angles belongs to longitudinal winding, and since circumferential winding can eliminate circumferential stress generated by internal pressure of a gas cylinder, and longitudinal winding can provide longitudinal stress, the invention adopts a mode of alternately winding circumferential winding and longitudinal winding to perform winding, thereby improving the overall performance of the carbon fiber coating layer.
Step (2) provides a forming die for compression molding, wherein the forming die comprises an upper die and a lower die which are identical in structure, and the upper die and the lower die comprise a die body, a protruding part extending from the die body and a plurality of screw holes respectively formed in two sides of the die body;
in this embodiment, the number of screw holes on both sides of the mold body is the same, and the screw holes are symmetrically arranged with respect to the central axis of the mold body.
The carbon fiber coating layer to be solidified is clamped between the protruding part of the upper die and the protruding part of the lower die, and the upper die and the lower die are locked through bolts to obtain a closed forming die;
specifically, a bolt is correspondingly arranged in each screw hole, the upper die and the lower die are locked through the bolts, and the disassembly and the assembly are convenient.
Step (4) placing the closed forming die in a heating furnace, and curing the carbon fiber filaments according to the preset compression molding process to obtain a carbon fiber coating layer;
the preset compression molding process comprises the following steps: heating to 90 ℃ from room temperature at a heating rate of 1.5 ℃/min, preserving heat for 1h, heating to 120 ℃ at a heating rate of 1.5 ℃/min, preserving heat for 2h, heating to 150 at a heating rate of 1.5 ℃/min, preserving heat for 3h, and naturally cooling with a forming die.
And (5) cutting the carbon fiber coating layer into a round carbon fiber sample with a preset diameter.
And after the forming die is cooled, taking out the carbon fiber coating layer wound on the flat template, cutting by using a cutting machine, and cutting the carbon fiber coating layer into a circular sample with a preset diameter, namely a circular carbon fiber sample.
Preferably, the preset diameter is 70 mm-100 mm.
S12, providing a first concentric annular coating layer and a second coating layer for covering a central through hole of the first coating layer, wherein the outer diameter of the first coating layer is the same as the preset diameter of the carbon fiber sample, and the diameter of the second coating layer is larger than the inner diameter of the first coating layer and smaller than the outer diameter of the first coating layer;
it should be noted that concentric rings are understood to mean that the central axis of the first cladding layer is aligned with the central axis of the central through hole of the first cladding layer, i.e. the center of the first cladding layer coincides with the center of the central through hole (irrespective of the thickness of the first cladding layer).
In this embodiment, the first coating layer may be obtained by processing a round coating layer having the same size as the carbon fiber sample as a raw material, that is, the step may be further to provide a round coating layer having the same size as the carbon fiber sample, and form a central through hole in a middle position of the round coating layer to obtain the first coating layer.
It is understood that the hollow portion of the first coating layer is a circular through hole, and the inner diameter of the first coating layer is the diameter of the hollow portion of the first coating layer.
In this embodiment, the outer diameter of the first coating layer is the same as the diameter of the carbon fiber sample, for example, when the diameter of the carbon fiber sample is 80mm, the outer diameter of the first coating layer is also 80mm.
In this embodiment, the inner diameter of the first cladding layer is related to the size and overlap length of the drill bit of the processing equipment, as will be further described below.
The second coating layer is used for covering the hollow part of the first coating layer, and the diameter of the second coating layer is limited to be larger than the inner diameter of the first coating layer and smaller than the outer diameter of the first coating layer, so that a sample lap joint part is formed after the carbon fiber sample, the first coating layer and the second coating layer are connected.
It will be appreciated that in this step, the dimensions of the first cladding layer and the second cladding layer are defined by diameters, corresponding to defining the outer periphery of the first cladding layer as being circular in shape, the inner periphery of the first cladding layer as being circular in shape, and the second cladding layer as being circular in shape.
S13, coating pretreated DW-3 low-temperature glue on the upper surface and the lower surface of the first coating layer respectively, and connecting the first coating layer with the carbon fiber sample and the second coating layer respectively to obtain a leakage sample to be solidified, wherein the first coating layer is clamped between the carbon fiber sample and the second coating layer, the second coating layer is covered on the central through hole, the central axis of the carbon fiber sample, the central axis of the first coating layer and the central axis of the second coating layer are all positioned on the same straight line, and the connecting part of the first coating layer and the second coating layer is a sample lap joint part;
the design of overlap joint portion adopts the lamination method, firstly sets up central through-hole on circular coating and obtains annular first coating, and then covers on first coating and establishes the second coating, because the size of second coating is greater than the size of central through-hole and is less than the size of first coating, then the part that second coating and first coating are connected just forms sample overlap joint portion, also can understand that the second coating surpasses the size of central through-hole and be sample overlap joint portion.
In this embodiment, the width of the sample lap portion is 1/2 of the difference between the diameter of the second cladding layer and the diameter of the central through hole, preferably, the width of the sample lap portion may be changed so that the width of the high pressure gas cylinder lap portion is optimized through a plurality of experiments, and when the size of the sample lap portion has an optimal value, the high pressure gas cylinder is the lightest in weight and good in leakage resistance. Specifically:
the second coating layer may be sized to take leakage samples with different overlap lengths for testing when the inner diameter of the first coating layer is determined, and the first coating layer may be sized to take leakage samples with different overlap lengths for testing when the diameter of the second coating layer is determined.
Preferably, the pretreatment of the DW-3 low-temperature glue comprises a defoaming process and a heating treatment process which are sequentially carried out. By preprocessing the DW-3 low-temperature glue, the viscosity of the glue can be improved, and the glue can be conveniently smeared.
Preferably, the bonding width is 15-25 mm.
More preferably, the defoaming process is performed in a vacuum stirring defoaming machine, the defoaming process comprises four stages which are sequentially performed, and in the first stage, the rotating speed of the stirring machine is 0r/min, and the vacuum degree in the defoaming machine is 30Kpa; in the second stage, the rotating speed of the stirrer is 500r/min, and the vacuum degree in the deaeration machine is 7-9Kpa; in the third stage, the revolution of the stirrer is 1900-2100r/min, and the vacuum degree in the deaerating machine is 3-5Kpa; in the fourth stage, the revolution of the stirrer is 450-600r/min, and the vacuum degree in the deaeration machine is 30Kpa.
More preferably, the time corresponding to the first stage is 0 to 10s, the time corresponding to the second stage is 11 to 25s, the time corresponding to the third stage is 26 to 115s, and the time corresponding to the fourth stage is 116 to 125s.
More preferably, the parameters of the heat treatment process are: heating temperature is 60-70℃: the heat preservation time is 50-70 min.
S14, sealing the leakage sample to be cured, and performing curing treatment according to a preset curing process to obtain the leakage sample.
The method for sealing the leak test piece to be solidified comprises the following steps:
the leak specimen to be cured was wound and fixed using a pressure-sensitive adhesive tape,
providing a flat plate mold, placing high-temperature sealant around the flat plate mold, preventing an isolating film (preventing the sealant from overflowing and being difficult to demold) from being placed on the flat plate mold, and placing a seepage sample to be solidified on the surface of the isolating film;
and placing a separation film, an airfelt and a vacuum bag above the leakage sample to be solidified in sequence, compacting the vacuum bag and the high-temperature sealant to enable the vacuum bag and the high-temperature sealant to be in sealing fit, communicating a vacuum nozzle communicated with the vacuum bag with a vacuum tube, and placing the vacuum bag and the vacuum tube in an autoclave after sealing.
The preset curing process comprises the following steps: when the vacuum pressure of the vacuum bag is pumped to 100Kpa (0.1 Mpa), stopping vacuumizing, placing for 10-15min, and placing into an autoclave for heating, pressurizing and curing when the vacuum degree is not lower than 100Kpa, wherein the curing process parameters are as follows: heating from room temperature to 40-55deg.C at 1.5 deg.C/min, heating to 0.05-0.1MPa at 0.02Mpa/min, and maintaining for 7-9h.
The vacuum pressure of 100kpa is vacuum pumping in a vacuum bag, and the pressure rising to 0.05-0.1Mpa at a pressure rising rate of 0.02Mpa/min is pressurizing in an autoclave. By adopting the curing process for curing, on one hand, DW-3 low-temperature glue at the temperature of-269 ℃ can be ensured not to be spread, and the leakage rate can not be influenced when the low-temperature glue is used for testing liquid nitrogen and liquid hydrogen environments, and on the other hand, the glue joint position can be ensured to have high strength under the low-temperature condition and can bear the pressure applied in the testing process.
It should be noted that, after being placed in the autoclave, the vacuum bag is vacuumized, and the sequence of the steps does not affect the implementation of the invention.
Referring to fig. 3 in combination, the present invention further provides a leakage test sample, which is prepared by the preparation method described above. The leakage test piece 300 comprises a first coating layer 310, a carbon fiber test piece 320 and a second coating layer 330, wherein the carbon fiber test piece 320 and the second coating layer 330 are respectively arranged on two sides of the first coating layer 310 and are connected with the first coating layer through DW-3 low-temperature glue, the first coating layer 310 is of a concentric annular structure, the second coating layer 330 is covered on a central through hole 311 of the first coating layer 310, and the central axis of the first coating layer 310, the central axis of the carbon fiber test piece 320 and the central axis of the second coating layer 330 are all positioned on the same straight line.
In this embodiment, the second cladding layer 330 includes a body portion 331 covering the central through hole 311, and a lap portion 332 connected to the first cladding layer 310.
Referring to fig. 3 to 6, the present invention further provides a method for testing a leakage sample, comprising the following steps:
step S21, providing a leakage sample and a detection device for detecting leakage performance;
wherein the structure of the leakage test sample is as described above, namely: the leakage test piece 300 comprises a first coating layer 310, a carbon fiber test piece 320 and a second coating layer 330, wherein the carbon fiber test piece 320 and the second coating layer 330 are respectively arranged on two sides of the first coating layer 310 and are connected with the first coating layer through DW-3 low-temperature glue, the first coating layer 310 is of a concentric annular structure, the second coating layer 330 is covered on a central through hole 311 of the first coating layer 310, and the central axis of the first coating layer 310, the central axis of the carbon fiber test piece 320 and the central axis of the second coating layer 330 are all positioned on the same straight line.
The seepage sample is prepared by adopting the preparation method, and the DW-3 low-temperature adhesive can resist the low temperature of-269 ℃, so that the DW-3 low-temperature adhesive layer can not influence the detection result of the seepage performance.
The inspection apparatus 100 includes a test jig 10, the test jig 10 including a first jig 11 and a second jig 12 disposed opposite to each other, the first jig 11 including a first jig main body portion 111, a first extension portion 112 extending from a middle portion of the first jig main body portion 111 in a direction away from the second jig 12, a groove 113 formed to be recessed inward from a surface of the first jig main body 111 toward the second jig 12, and a first passage 114 formed to penetrate the first extension portion 112 and a bottom of the groove 113 in a first direction; the second jig 12 includes a second jig main body portion 121, a second extension portion 122 extending from a middle portion of the second jig main body portion 121 in a direction away from the first jig 11, a boss 123 extending from the second jig main body portion 121 in a direction toward the first jig 12, and a second passage 124 formed through the second extension portion 122 and the boss 123 in the first direction, the boss 123 having a shape matching that of the groove 113; the detection device 100 further comprises a low temperature box 20 for accommodating the test fixture 10, a liquid nitrogen tank 30 communicated with the low temperature box 10, a helium tank 40 communicated with a first channel 114 of the test fixture 10 through a helium pipeline 91, a vacuum pump 50 communicated with the helium pipeline 91 through a first connecting pipeline 92, a pressure gauge 60 arranged at one end of the helium pipeline 91 close to the helium tank, and a helium mass spectrometer leak detector 70 communicated with a second channel 124 of the test fixture 10 through a second connecting pipeline 93; the test fixture 10 is housed in the low temperature box 20.
In this embodiment, the first direction is an extending direction of the first channel and the second channel.
In this embodiment, the first channel 114 is a helium inlet and the second channel 124 is a helium outlet.
In this embodiment, the pressure gauge 60 is configured to detect a pressure between the outlet end of the helium tank and the helium inlet end of the first fixture, so as to control the pressure of the detected helium.
Step S22, installing the leakage sample in the groove of the first clamp, wherein the carbon fiber sample and the first coating layer are contained in the groove, and the second coating layer is embedded in the first channel or the second channel;
and S23, after the components of the detection device are connected, testing the leakage condition of the leakage sample according to a preset testing process, and acquiring an indication value of the helium mass spectrometer leak detector.
The test process comprises the following steps: firstly, starting a vacuum pump, pumping helium in the helium pipeline, closing the vacuum pump when a pressure gauge shows-0.1 MPa, closing an air outlet valve of the sample clamp, starting an air supply switch of a helium tank, and closing the air supply switch of the helium tank when the data of the pressure gauge reaches 4-5 bar; after the indication of the pressure gauge is stable, an outlet switch of the liquid nitrogen tank is started, so that the low-temperature box starts to cool, the low-temperature box is kept at the temperature of-196 ℃ to-180 ℃, high-pressure helium passes through a leakage sample to be detected, and an indication value of the helium mass spectrum leak detector is obtained, wherein the indication value is the leakage rate of the leakage sample to be detected.
The foregoing is a further detailed description of the invention in connection with specific preferred embodiments, and is not intended to limit the practice of the invention to such description. It will be apparent to those skilled in the art that several simple deductions and substitutions can be made without departing from the spirit of the invention, and these are considered to be within the scope of the invention.
Claims (10)
1. The preparation method of the leakage sample of the high-pressure gas cylinder with the lap joint part, the high-pressure gas cylinder is used in a liquid oxygen environment or a liquid hydrogen environment, the shell wall of the high-pressure gas cylinder is of a multi-layer structure, and the metal layer positioned at the outermost side comprises a body part just coating the metal layer or the composite material layer at the next outer side and a cylinder lap joint part extending from the body part, the preparation method of the leakage sample comprises the following steps:
(1) Preparing a carbon fiber coating layer according to a preset compression molding process, and cutting the carbon fiber coating layer into a round carbon fiber sample with a preset diameter;
(2) Providing a first concentric annular coating layer and a second coating layer, wherein the second coating layer is used for covering a central through hole of the first coating layer, the outer diameter of the first coating layer is the same as the preset diameter of the carbon fiber sample, and the diameter of the second coating layer is larger than the inner diameter of the first coating layer and smaller than the outer diameter of the first coating layer;
(3) Coating pretreated DW-3 low-temperature glue on the upper surface and the lower surface of the first coating layer respectively, and connecting the first coating layer with the carbon fiber sample and the second coating layer respectively to obtain a leakage sample to be solidified, wherein the first coating layer is clamped between the carbon fiber sample and the second coating layer, the second coating layer is covered on the central through hole, the central axis of the carbon fiber sample, the central axis of the first coating layer and the central axis of the second coating layer are all positioned on the same straight line, and the connecting part of the first coating layer and the second coating layer is a sample lap joint part;
(4) And sealing the leakage sample to be cured, and then placing the sealed leakage sample into an autoclave, and curing according to a preset curing process to obtain the leakage sample.
2. The method of claim 1, wherein the predetermined compression molding process comprises: heating to 90 ℃ from room temperature at a heating rate of 1.5 ℃/min, preserving heat for 1h, heating to 120 ℃ at a heating rate of 1.5 ℃/min, preserving heat for 2h, heating to 150 at a heating rate of 1.5 ℃/min, preserving heat for 3h, and finally naturally cooling.
3. The method of claim 1, wherein the predetermined curing process comprises: the temperature is raised to 40-55 ℃ from room temperature at the heating rate of 1.5 ℃/min, the pressure in the autoclave is raised to 0.05-0.1MPa at the boosting rate of 0.02Mpa/min, the temperature is kept for 7-9h, and the vacuum bag wrapping the leakage sample to be solidified is vacuumized at 0.1Mpa in the whole process.
4. The method according to claim 1, wherein the pretreatment of the DW-3 cryogel comprises a defoaming process and a heat treatment process performed sequentially.
5. The method according to claim 4, wherein the defoaming process is performed in a vacuum stirring defoaming machine, the defoaming process comprises a fourth stage which is performed in sequence, and in the first stage, the rotation speed of the stirring machine is 0r/min, and the vacuum degree in the defoaming machine is 30Kpa; in the second stage, the rotating speed of the stirrer is 500r/min, and the vacuum degree in the deaeration machine is 7-9Kpa; in the third stage, the revolution of the stirrer is 1900-2100r/min, and the vacuum degree in the deaerating machine is 3-5Kpa; in the fourth stage, the revolution of the stirrer is 450-600r/min, and the vacuum degree in the deaeration machine is 30Kpa.
6. The method according to claim 5, wherein the first stage corresponds to a time of 0 to 10 seconds, the second stage corresponds to a time of 11 to 25 seconds, the third stage corresponds to a time of 26 to 115 seconds, and the fourth stage corresponds to a time of 116 to 125 seconds.
7. The method according to any one of claims 4 to 6, wherein the parameters of the heat treatment process are: the heating temperature is 60-70℃: the heat preservation time is 50-70 min.
8. The method of claim 1, wherein the step (1) comprises the steps of:
providing a flat template, and winding carbon fiber yarns immersed in a glue groove on the flat template according to a preset winding process to obtain a carbon fiber coating layer to be solidified;
providing a forming die for compression molding, wherein the forming die comprises an upper die and a lower die which are identical in structure, and the upper die and the lower die comprise a die body, a protruding part extending from the die body and a plurality of screw holes respectively formed in two sides of the die body;
clamping the carbon fiber coating layer to be solidified between the protruding part of the upper die and the protruding part of the lower die, and locking the upper die and the lower die through bolts to obtain a closed forming die;
placing the closed forming die in a heating furnace, and curing the carbon fiber filaments according to the preset compression molding process to obtain a carbon fiber coating;
cutting the carbon fiber coating layer into a round carbon fiber sample with a preset diameter.
9. The leakage sample is prepared by the preparation method of any one of claims 1 to 8, and comprises a first coating layer, a carbon fiber sample and a second coating layer, wherein the carbon fiber sample and the second coating layer are respectively arranged on two sides of the first coating layer and are connected with the first coating layer through DW-3 low-temperature glue, the first coating layer is of a concentric annular structure, the second coating layer is covered on a central through hole of the first coating layer, and the central axis of the first coating layer, the central axis of the carbon fiber sample and the central axis of the second coating layer are all positioned on the same straight line.
10. A method of testing a leak specimen, comprising the steps of:
providing a leakage sample and a detection device for leakage performance detection; wherein,,
the leak test is the leak test of claim 9;
the detection device comprises a test clamp, wherein the test clamp comprises a first clamp and a second clamp which are oppositely arranged, the first clamp comprises a first clamp main body part, a first extension part extending from the middle part of the first clamp main body part to a direction far away from the second clamp, a groove formed by inwards sinking from the surface of the first clamp main body part towards the second clamp, and a first channel formed by penetrating through the first extension part and the bottom of the groove along a first direction; the second clamp comprises a second clamp main body part, a second extension part extending from the middle part of the second clamp main body part to a direction far away from the first clamp, a boss extending from the second clamp main body part to a direction of the first clamp, and a second channel penetrating through the second extension part and the boss along the first direction, wherein the shape of the boss is matched with that of the groove; the detection device further comprises a low-temperature box for accommodating the test fixture, a liquid nitrogen tank communicated with the low-temperature box, a helium tank communicated with the first channel of the test fixture through a helium pipeline, a vacuum pump communicated with the helium pipeline through a first connecting pipeline, a pressure gauge arranged at one end of the helium pipeline close to the helium tank, and a helium mass spectrum leak detector communicated with the second channel of the test fixture through a second connecting pipeline;
installing the leakage sample in the groove of the first clamp, wherein the carbon fiber sample and the first coating layer are contained in the groove, and the second coating layer is embedded in the first channel or the second channel; after all parts of the detection device are connected, testing the leakage condition of the leakage sample according to a preset testing process, and acquiring an indication value of the helium mass spectrometer leak detector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310298940.2A CN116242553A (en) | 2023-03-24 | 2023-03-24 | Preparation method and test method of leakage sample of high-pressure gas cylinder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310298940.2A CN116242553A (en) | 2023-03-24 | 2023-03-24 | Preparation method and test method of leakage sample of high-pressure gas cylinder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116242553A true CN116242553A (en) | 2023-06-09 |
Family
ID=86633274
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310298940.2A Pending CN116242553A (en) | 2023-03-24 | 2023-03-24 | Preparation method and test method of leakage sample of high-pressure gas cylinder |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116242553A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117744452A (en) * | 2024-02-20 | 2024-03-22 | 中南大学 | Leakage performance characterization method for lap joint area of composite pressure vessel |
-
2023
- 2023-03-24 CN CN202310298940.2A patent/CN116242553A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117744452A (en) * | 2024-02-20 | 2024-03-22 | 中南大学 | Leakage performance characterization method for lap joint area of composite pressure vessel |
| CN117744452B (en) * | 2024-02-20 | 2024-05-03 | 中南大学 | Leakage performance characterization method for lap joint area of composite pressure vessel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN116242553A (en) | Preparation method and test method of leakage sample of high-pressure gas cylinder | |
| CN111337411B (en) | Method and device for testing radial permeability of full-diameter shale | |
| CN110068430A (en) | A kind of leakage test method of aerospace composite tank | |
| CN110068431A (en) | A kind of leakage test method of aerospace composite tank at low ambient temperatures | |
| CN110579432B (en) | Dual-purpose sealing assembly and operation method | |
| WO2020224632A1 (en) | Method for testing leakage performance of aerospace composite material member in low temperature environment | |
| CN116222902A (en) | Hydrogen permeation/leakage/fatigue integrated measurement device and process | |
| CN105910761A (en) | Tube flange gas leakage detection device | |
| CN101865754A (en) | Device for detecting gas tightness of composite material laminated plate | |
| CN113188974A (en) | High-pressure hydrogen permeation test device and method for liner material of IV-type gas cylinder | |
| CN117723406A (en) | True three-dimensional stress seepage coupling test system and method for deep geological reservoir rock mass | |
| US5309752A (en) | Leakage measurement into a gas-charged collapsible container | |
| CN109932141A (en) | A kind of leakage system safety testing device for space flight low-temperature composite material tank | |
| US9914244B2 (en) | Bladder system for curing composite parts | |
| CN215374385U (en) | Vertical dewar bottle copper pipe leak hunting frock | |
| CN203893999U (en) | Leak-detection test bed | |
| US9227384B2 (en) | Pressure debulking system | |
| CN210269550U (en) | Concrete permeability test piece sealing device and tester | |
| CN221484760U (en) | Pressure vessel gas tightness verifying attachment | |
| CN113029551A (en) | Ultralow temperature valve test device | |
| CN207336004U (en) | A kind of low temperature valve cryogenic property tests system | |
| CN111474057B (en) | Movable type pipe hydrostatic test device and test method | |
| KR20230004613A (en) | complex pressure vessels | |
| CN219348111U (en) | Steel skeleton composite pipeline installation detection equipment | |
| CN117744452B (en) | Leakage performance characterization method for lap joint area of composite pressure vessel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |