Method for testing sealing performance of high-pressure container
By using liquefied gas pumping and compression, vaporization and tracer gas mixing methods in high-pressure container sealing inspection, the existing methods have solved the problems of high energy consumption, high cost and complex management, and achieved safer and more economical sealing inspection.
Patent Information
- Application Number
- CN202411637324.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-11-23
- Filing Date
- 2024-11-15
- Publication Date
- 2025-05-23
AI Technical Summary
Existing high-pressure container sealing inspection methods are energy-consuming, costly and complex in management, especially when using hydrogen tracer gas, the risk of fire or explosion is required.
By pumping and compressing the liquefied gas, vaporizing and mixing with the compressed tracer gas in a buffer container, forming a gas mixture to fill the high-pressure container, and leak detection is performed in the buffer container, avoiding multiple gas compression and the use of heat exchangers.
A more energy-free sealing inspection method is achieved, reducing costs and simplifying management processes, especially when using flammable tracer gases, reducing the risk of fire or explosion.
Smart Images
Figure CN120027979A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a testing method for testing the tightness of a high-pressure container at the end of a production line, in particular for a motor vehicle, and to a facility for testing the tightness of said high-pressure container at the end of a production line. Background Art
[0002] All high-pressure vessels must be tested for sealing (airtightness) before being put into use. The sealing test room is at the end of the production line, during the gas leak test (i.e., "gas leak test"). During this test, the container is placed in an implementation chamber to be filled with gas until the test pressure. The test pressure, that is, the pressure inside the container for inspection, is generally higher than or equal to the maximum use pressure of the container (which is also called the nominal pressure). The implementation chamber is equipped with sensors to detect possible gas leaks. The leak test should be carried out at a filling temperature below 85°C but above -40°C. The gas used is generally a gas containing 5% by weight of H 2 (dihydrogen, commonly referred to as hydrogen) and 95 wt% N 2 A mixture of nitrogen (dinitrogen, usually called nitrogen) in which hydrogen is used as a tracer gas. Helium can be used instead of hydrogen. The tracer gas is used to detect leaks with the aid of a spectrometer.
[0003] Gas leak testing using nitrogen and hydrogen gas sources is known in the prior art. Such testing requires the use of a series of gas compressors, a series of heat exchangers for controlling the compressor input temperature, and valves for controlling the compressor input pressure. Such testing therefore consumes a lot of energy and is very costly. Moreover, it is complex to manage because it involves many steps. Summary of the invention
[0004] In particular, the object of the invention is to provide a method for testing the tightness of a high-pressure container which is less energy-intensive.
[0005] To this end, the subject of the present invention is a method for testing the tightness of a high-pressure container. The method comprises the following steps:
[0006] a) pumping and compressing liquefied gas from a liquefied gas source by means of a pump to obtain compressed liquefied gas at a pressure of 500 to 1000 bar; and then
[0007] b) vaporizing the compressed liquefied gas obtained in step a) to obtain vaporized liquefied gas;
[0008] c) compressing the tracer gas to obtain a compressed tracer gas at a pressure of 500 to 1000 bar;
[0009] d) mixing the vaporized liquefied gas obtained in step b) with the compressed tracer gas obtained in step c) in a buffer container to obtain a gas mixture;
[0010] e) filling the high-pressure vessel to be tested with the gas mixture obtained in step d); then
[0011] f) Check whether the high-pressure container to be inspected has any leakage of tracer gas.
[0012] Since the gas is pumped and vaporized in liquefied (liquid) form rather than in gaseous form, a series of gas compressors, a series of heat exchangers and a series of valves for controlling the pressure can be avoided, thereby providing a method that consumes less energy and is less expensive.
[0013] It should be noted that a buffer container is advantageously used for mixing the vaporized liquefied gas with the compressed tracer gas, but it is also conceivable to directly feed the tracer gas into the container to be inspected and to allow the vaporized liquefied gas to mix with the tracer gas in the container to be inspected. However, despite the fact that compression of the tracer gas is not necessary and the use of a buffer container is not necessary, the proposed method is particularly safe.
[0014] Preferably, a "buffer container" is a container whose volume can be filled with a plurality of high-pressure containers to be tested. Thus, with a buffer container, it is possible to test a plurality of high-pressure containers by mixing the gases only once. Without a buffer container, the gases would have to be mixed as many times as there are containers, which is more restrictive.
[0015] Furthermore, the increasing number of separate mixing operations to be carried out makes it more difficult to obtain a mixture of the quality required for the leak-tightness test each time.
[0016] The quality of the gas mixture is determined by determining the proportions of each gas present in the gas mixture. A gas mixture of the desired quality is a gas mixture in which the proportions of each gas present in the gas mixture correspond to the target proportions. Thus, by means of the buffer container, it is not necessary to equip each container to be tested with a device for testing the quality of the gas mixture. This results in a simpler installation and a method that takes less time to implement.
[0017] Furthermore, in the case where the tracer gas is hydrogen, the risk of fire or explosion must be managed, which complicates the leak testing, as the gas is flammable. By mixing the hydrogen with the liquefied gas in a buffer vessel, the need to manage these risks at each high pressure vessel to be tested can be avoided.
[0018] This provides a testing facility that requires less complexity but is more reliable.
[0019] According to the sealing test method of the present invention, other optional features that can be adopted individually or in combination are:
[0020] - The pump comprises a cold head. The cold head of the pump is the part of the pump that serves as the inlet-outlet for the liquefied gas.
[0021] - The pump is a cryogenic pump (also called a condensate pump).
[0022] Thereby, liquefied gas having a negative temperature (sub-zero) can be compressed.
[0023] -The cryopump is a piston type cryopump.
[0024] A high pressure vessel is a vessel intended to be filled with gas at a maximum filling pressure of 875 bar. It is for example a type IV high pressure vessel consisting of an inner shell called "liner" surrounded by a reinforcement structure, and its maximum use pressure (also called nominal pressure) is 700 bar.
[0025] -High-pressure vessels are designed to contain hydrogen gas under high pressure.
[0026] - Mixing of the vaporized liquefied gas with the compressed tracer gas is carried out in a buffer vessel at a pressure of 500 to 1000 bar.
[0027] - Test pressure is 350 to 700 bar.
[0028] - The liquefied gas is liquid nitrogen. The advantage of this gas is that it is not expensive and its use does not involve the same risks as hydrogen, like for example the risk of creating an explosive gas atmosphere.
[0029] - Pumping liquefied nitrogen from a source of liquefied nitrogen at a pressure of about 10 bar, such as a liquefied nitrogen storage container compressed at a pressure below 15 bar, such as 10 bar.
[0030] - Pumping and compressing of liquefied nitrogen by cryogenic pumps capable of operating at temperatures down to -253°C.
[0031] -The tracer gas can be either hydrogen or helium, with helium being more expensive but less hazardous than hydrogen.
[0032] Advantageously, the mixture of vaporized liquefied gas and tracer gas is a mixture containing 95 to 96% by weight of nitrogen and 4 to 5% by weight of hydrogen. Alternatively, the gas mixture is a mixture containing 95 to 98% by weight of nitrogen and 2 to 5% by weight of helium.
[0033] - pumping and compressing the liquefied gas to obtain a compressed liquefied gas at a pressure of 900 to 1000 bar, preferably about 1000 bar, and compressing the tracer gas to obtain a compressed tracer gas at a pressure of 900 to 1000 bar, preferably about 1000 bar. Thus, there is no need to compress the gas mixture before filling the container to be inspected, it is directly at the desired pressure.
[0034] - pumping and compressing the liquefied gas to obtain a compressed liquefied gas at a pressure of about 500 bar, and compressing the tracer gas to obtain a compressed tracer gas at a pressure of about 500 bar, said method comprising, before step e) of filling the high-pressure vessel to be inspected with the gas mixture obtained in step d),
[0035] - A step of compressing the gas mixture obtained in step d) so as to bring its pressure to approximately 1000 bar.
[0036] - said method comprises, before step e) of filling the high-pressure container to be inspected with the gas mixture obtained in step d), a step of cooling said gas mixture, preferably by means of a heat exchanger which is itself cooled by a stream of liquefied gas coming from a liquefied gas source.
[0037] The temperature of the gas mixture required for filling the high-pressure container is thereby controlled and should be kept between -40° C. and 85° C. A liquefied gas source is thereby advantageously used for cooling the gas mixture.
[0038] The method comprises, after step b) of vaporizing the liquefied gas and before step d) of mixing the gases in the buffer vessel, a step of cooling the vaporized liquefied gas, preferably by injecting liquefied gas from a liquefied gas source into the vaporized liquefied gas.
[0039] The vaporized liquefied gas is thereby cooled.
[0040] - Liquefied gas flows (circulates) from the liquefied gas source to the cold head of the pump.
[0041] The liquefied gas source is thus advantageously used for cooling the pump.
[0042] The liquefied gas can be circulated to the cold head of the pump through a thermosyphon system.
[0043] The method comprises, before step d) of mixing the gases in the buffer vessel, a step of dosing each gas obtained in steps b) and c) to control the proportion of each gas in the gas mixture. Preferably, this control is performed continuously.
[0044] In order to obtain a gas mixture with the desired quality, the proportion of each gas is controlled during the injection of each gas into the buffer vessel. Preferably, the proportion of each gas is controlled by a mass flow meter (flow meter) measuring the mass flow rate of each gas during its injection into the buffer vessel. A device for dosing each gas is also provided. The dosing device is controlled by the mass flow meter according to the mass flow rate measurements obtained. The proportion of each gas present in the gas mixture obtained in step d) is thereby preferably continuously controlled.
[0045] The subject of the present invention is also a facility for implementing a method for testing the tightness of a high-pressure container, the facility comprising:
[0046] - Implementation chamber;
[0047] - a pump configured to pump liquefied gas and compress it to a pressure of 500 to 1000 bar;
[0048] - carburetor;
[0049] - a compressor configured to compress the tracer gas to a pressure of 500 to 1000 bar;
[0050] - Buffer container.
[0051] It is understood that the device comprises at least one pump, at least one vaporizer, and at least one compressor.
[0052] Thus, maintenance operations can be carried out without stopping the production line.
[0053] Optional further features which may be employed individually or in combination according to the facility:
[0054] The installation comprises two pumps configured to pump liquefied gas and compress it to a pressure of 500 to 1000 bar, and / or comprises two compressors configured to compress the tracer gas to a pressure of 500 to 1000 bar, and / or comprises two vaporizers.
[0055] Thus, maintenance operations can be performed without stopping the production line.
[0056] The cold head of the pump comprises means for circulating liquefied gas from a liquefied gas source.
[0057] The installation further comprises a gas analyzer arranged downstream of the buffer vessel and upstream of the high-pressure vessel to be inspected.
[0058] Thereby, the proportion of each gas present in the gas mixture output from the buffer vessel is continuously controlled.
[0059] - The plant further comprises a conduit for injecting liquefied gas from a liquefied gas source into the boil-off liquefied gas, the conduit preferably being a bypass conduit of the boil-off.
[0060] The boiled-off liquefied gas is thereby cooled. The cooled liquefied gas is then introduced into the buffer container, thereby lowering the temperature of the gas mixture to be introduced into the high-pressure container to be tested. BRIEF DESCRIPTION OF THE DRAWINGS
[0061] The invention will be better understood from the following description which is provided by way of example only and which is made with reference to the accompanying drawings, in which:
[0062] [ Figure 1 ] is a schematic diagram of a facility for implementing a sealing inspection method according to the present invention.
[0063] [ Figure 2 ] schematically shows the fluid circulation in the method for testing the sealing according to the first embodiment of the present invention.
[0064] [ Figure 3 ] schematically shows the fluid circulation in the method for testing the sealing according to the second embodiment of the present invention. DETAILED DESCRIPTION
[0065] In the drawings, elements similar to elements in other drawings are denoted by the same reference numerals.
[0066] exist Figure 1 , a schematic diagram of a facility for implementing a leak-tightness test method, indicated by the general reference numeral 10, is shown. In the facility 10 shown, the leak-tightness of a high-pressure container 12 can be tested. The facility 10 comprises an implementation chamber 14, in which the high-pressure container 12 is placed to be filled with gas until the test pressure is reached. The implementation chamber 14 is equipped with sensors, not shown, to detect possible gas leaks. Figure 1 Also shown in the figure is a liquefied gas source 16, and a tracer gas source 18. The facility 10 also includes a pump 20 configured to pump liquefied gas and compress it to a pressure of 500 to 1000 bar, a vaporizer 22, a compressor 24 configured to compress the tracer gas to a pressure of 500 to 1000 bar, and a buffer container 26. The liquefied gas is stored in the liquefied gas source 16 at a pressure of 10 bar. In one example, the liquefied gas source 16 is a container containing liquefied gas. Thus, the pump 20 pumps the liquefied gas at a pressure of 10 bar and compresses it to a pressure of 500 to 1000 bar. The pump 20 is a cryogenic pump including a cold head not shown.
[0067] The inspection method according to the present invention comprises the following steps:
[0068] a) pumping and compressing liquefied gas from a liquefied gas source 16 by means of a pump 20 to obtain compressed liquefied gas at a pressure of 500 to 1000 bar;
[0069] b) vaporizing the compressed liquefied gas obtained in step a) to obtain vaporized liquefied gas;
[0070] c) compressing the tracer gas to obtain a compressed tracer gas at a pressure of 500 to 1000 bar;
[0071] d) mixing the vaporized liquefied gas obtained in step b) with the compressed tracer gas obtained in step c) in a buffer container 26 to obtain a gas mixture;
[0072] e) filling the high-pressure container 12 to be inspected with the gas mixture obtained in step d); then
[0073] f) Check whether the high-pressure container 12 to be inspected has any tracer gas leakage.
[0074] exist Figure 1 Among the facilities 10 shown:
[0075] - step a) is carried out at the pump 20;
[0076] - step b) is carried out at the vaporizer 22;
[0077] - step c) is carried out at the compressor 24;
[0078] The gas leakage check of step f) is carried out in the carrying out chamber 14 .
[0079] Preferably, step c) is performed after steps a) and b), however, it can also be performed before or simultaneously with step a) and / or step b).
[0080] exist Figure 1 In the example shown, the high-pressure container 12 is intended to contain high-pressure hydrogen. The mixing of the vaporized liquefied gas with the compressed tracer gas in the buffer container 26 is carried out, for example, at a pressure of 500 to 1000 bar. The liquefied gas is, for example, nitrogen. The mixture of vaporized liquefied gas and tracer gas can be a mixture containing nitrogen in a proportion of 95 to 96% by weight and hydrogen in a proportion of 4 to 5% by weight.
[0081] Generally, before step d) of mixing the gases in the buffer container (26), a step of determining the dosage of each gas obtained in steps b) and c) is required to control the proportion of each gas in the gas mixture. Preferably, this control is implemented by a mass flow meter 28, preferably continuously.
[0082] exist Figure 2Schematically shows the fluid circulation (circulation) in the method for testing the sealing according to the first embodiment of the present invention. In this embodiment, the pump 20 is configured to pump the liquefied gas and compress it to a pressure of 900 to 1000 bar, and the compressor 24 is configured to pump the tracer gas and compress it to a pressure of 900 to 1000 bar. The liquefied gas is pumped and compressed to obtain a compressed liquefied gas at a pressure of 900 to 1000 bar, and the tracer gas is compressed to obtain a compressed tracer gas at a pressure of 900 to 1000 bar. Thus, in this embodiment, the mixing of the vaporized liquefied gas and the compressed tracer gas in the buffer container 26 is carried out at a pressure of 900 to 1000 bar. Figure 2 The installation 10 partially shown in FIG. 1 also includes a high-pressure vessel (in Figure 2 ) upstream of the gas analyzer 50. Thus, after step d) of mixing the gases in the buffer container 26, but before step e) of filling the container 12 to be inspected with the gas mixture obtained in step d), the quality of the gas mixture obtained in step d) is controlled. The gas analyzer 50 is, for example, a chromatograph. The control of the gas ratios is managed at the gas mixture control panel 30. Figure 2 1 , a heat exchanger 32 is also shown, which is located near the facility 10. The heat exchanger 32 itself is cooled by a stream of liquefied gas, which is shown by arrow 33, coming from the liquefied gas source 16. Thus, the method according to this embodiment comprises, before step e) of filling the container 12 to be inspected with the gas mixture obtained in step d), a step of cooling the gas mixture by means of the heat exchanger 32. The temperature of the gas mixture required for filling the high-pressure container is thereby controlled, which temperature should be kept between -40°C and 85°C. Thus, the liquefied gas source 16 is advantageously used for cooling the gas mixture.
[0083] Figure 2The facility 10 shown comprises two pumps 20 configured to pump and compress liquefied gas to a pressure of 900 to 1000 bar, two compressors 24 configured to compress the tracer gas to a pressure of 900 to 1000 bar, and two vaporizers 22. The pumps 20 are arranged on a pump support 34 (also referred to in English as "pump skid"), and the two compressors 24 are arranged on a compressor support 36 (also referred to in English as "compressor skid"). A control panel 38 of the vaporizer 22 is also shown. By providing two pumps 20, two compressors 24 and two vaporizers 22, maintenance operations can be carried out without stopping the production line. In fact, in each pair of equipment, one of the two equipment is redundant, in other words, the other is used when one stops. Thus, when one equipment must be stopped, for example to perform a maintenance operation, the redundant equipment is operated to take over the stopped equipment, which allows to avoid stopping the production line during the maintenance operation.
[0084] exist Figure 2 In the embodiment, the liquefied gas source 16 comprises a ground connection 35, a 3G connection 37, and a power supply 39. The ground connection 35 relates to the entire facility 10. In the example where the liquefied gas source 16 is a container containing liquefied gas, a sensor, such as a pressure sensor, is used to measure the level of the liquefied gas in the container. The 3G connection is a mobile Internet connection that allows the liquefied gas supplier to be informed of the level of the liquefied gas in the container in order to plan the filling of the container when the level reaches a predetermined threshold (for example, when the level reaches 20% of the nominal capacity of the container).
[0085] At startup of the installation 10, the cold head of the pump 20 is at ambient temperature. In order to ensure good operation of the pump 20, the cold head can be brought to its optimal operating temperature (-196° C. for liquid nitrogen). To this end, the cold head is supplied with subcooled liquefied gas (in the case of liquid nitrogen, this involves liquid nitrogen brought to a temperature below -196° C.) by a subcooling device not shown.
[0086] The liquefied gas source is thus advantageously used to supercool the cold head of the pump 20 (subcooling) in order to ensure good operation of the pump 20 when the installation 10 is started up.
[0087] Figure 2 The facility 10 also includes a pipeline, not shown, for injecting liquefied gas from the liquefied gas source 16 into the boil-off liquefied gas. Thus, in this example, after step b) of boil-off the liquefied gas, but before step d) of mixing the gases in the buffer container 26, the method includes a step of cooling the boil-off liquefied gas by injecting liquefied gas from the liquefied gas source 16 into the boil-off liquefied gas.
[0088] Figure 2The illustrated installation 10 also comprises a gas analyser 40 for analysing the gas output by the compressor 24. The analyser 40 makes it possible to detect the presence of hydrocarbons in the compressed gas, for example oil in the case where the compressor 24 is lubricated.
[0089] exist Figure 3 Schematically shows the fluid circulation (circulation) in the method for checking the tightness according to the second embodiment of the present invention. In this embodiment, the pump 20 is configured to pump the liquefied gas and compress it to a pressure of about 500 bar, and the compressor 24 is configured to pump the tracer gas and compress it to a pressure of about 500 bar. The liquefied gas is pumped and compressed to obtain a compressed liquefied gas at a pressure of about 500 bar, and the tracer gas is compressed to obtain a compressed tracer gas at a pressure of about 500 bar. Thus, in this embodiment, the mixing of the vaporized liquefied gas and the compressed tracer gas in the buffer container 26 is carried out at a pressure of about 500 bar. Figure 3 The design also includes a compressor 44 capable of compressing the gas mixture stored in the buffer container 26 to a pressure of about 1000 bar. In this embodiment, the method actually includes a step of compressing the gas mixture obtained in step d) to obtain a compressed gas mixture at a pressure of about 1000 bar before the step e) of filling the high-pressure container 12 to be inspected with the gas mixture obtained in step d). The compressed gas mixture at about 1000 bar is then stored in a storage container 46. Based on this storage container 46, the step e) of filling the high-pressure container to be inspected is performed. Figure 3 The installation 10 shown comprises two compressors 44, one of which is redundant, like the two compressors 24. In the event of a stoppage of one of the compressors 44, the other is used.
[0090] Figure 2 and Figure 3 The facility 10 also includes a particle filter and an oil filter 48 for maintenance of the facility.
[0091] The invention is not limited to the embodiments described, and other embodiments will be apparent to the person skilled in the art. It is particularly feasible to use other tracer gases than hydrogen, such as, for example, helium. It is also feasible to use other liquefied gases.
[0092] List of Reference Numerals
[0093] 10: Facilities
[0094] 12: High pressure vessel
[0095] 14: Implementing the Chamber
[0096] 16: Liquefied gas source
[0097] 18: Tracer gas source
[0098] 20: Pump
[0099] 22: Carburetor
[0100] 24: Compressor
[0101] 26: Buffer container
[0102] 28: Mass flow meter
[0103] 30: Gas mixture control panel
[0104] 32: Heat exchanger
[0105] 33: Liquefied gas flow
[0106] 34: Pump support
[0107] 35: Ground connection
[0108] 36: Compressor support
[0109] 37: 3G connection
[0110] 38: Carburetor control panel
[0111] 39: Power supply
[0112] 40: Gas Analyzer
[0113] 44: Compressor from 400 to 1000 bar
[0114] 46: Storage Container
[0115] 48: Particle and oil filters
[0116] 50: Gas Analyzer
Claims
1. A method for testing the sealing performance of a high-pressure container (12), wherein: The method comprises the following steps: a) pumping and compressing liquefied gas from a liquefied gas source (16) by means of a pump (20) to obtain compressed liquefied gas at a pressure of 500 to 1000 bar; b) vaporizing the compressed liquefied gas obtained in step a) to obtain vaporized liquefied gas; c) compressing the tracer gas to obtain a compressed tracer gas at a pressure of 500 to 1000 bar; d) mixing the vaporized liquefied gas obtained in step b) with the compressed tracer gas obtained in step c) in a buffer container (26) to obtain a gas mixture; e) filling the high-pressure container (12) to be tested with the gas mixture obtained in step d); then f) Checking whether the high-pressure container (12) to be inspected has any leakage of the tracer gas.
2. The sealing test method according to the preceding claim, wherein: The liquefied gas is pumped and compressed to obtain a compressed liquefied gas at a pressure of 900 to 1000 bar, preferably about 1000 bar, and the tracer gas is compressed to obtain a compressed tracer gas at a pressure of 900 to 1000 bar, preferably about 1000 bar.
3. The sealing inspection method according to claim 1, wherein: Pumping and compressing the liquefied gas to obtain a compressed liquefied gas at a pressure of about 500 bar, and compressing the tracer gas to obtain a compressed tracer gas at a pressure of about 500 bar, the method comprising, before step e) of filling the high-pressure container (12) to be inspected with the gas mixture obtained in step d), - A step of compressing the gas mixture obtained in said step d) so as to obtain a gas mixture at a pressure of about 1000 bar.
4. A sealing test method as claimed in any one of the preceding claims, comprising, before step e) of filling the high-pressure container (12) to be tested with the gas mixture obtained in step d), a step of cooling the gas mixture, preferably by means of a heat exchanger (32) which is itself cooled by the liquefied gas flow (33) from the liquefied gas source (16).
5. A sealing inspection method as claimed in any one of the preceding claims, comprising, after step b) of vaporizing the liquefied gas and before step d) of mixing the gas in a buffer container (26), a step of cooling the vaporized liquefied gas, preferably by injecting liquefied gas from the liquefied gas source (16) into the vaporized liquefied gas.
6. The sealing test method according to any one of the preceding claims, wherein: The liquefied gas flows from the liquefied gas source (16) to the cold head of the pump.
7. A sealing inspection method as claimed in any one of the preceding claims, comprising, before step d) of mixing gases in a buffer container (26), a step of determining a dosage for each gas obtained in steps b) and c) to control the proportion of each gas in the gas mixture.
8. A facility (10) for implementing the method for testing the tightness of a high-pressure container (12) as claimed in any one of the preceding claims, the facility comprising: - an implementation chamber (14); - a pump (20) configured to pump liquefied gas and compress it to a pressure of 500 to 1000 bar; - a carburetor (22); - a compressor (24) configured to compress the tracer gas to a pressure of 500 to 1000 bar; - A buffer container (26).
9. Installation (10) according to the preceding claim, comprising two pumps (20) configured to pump liquefied gas and compress it to a pressure of 500 to 1000 bar, and / or comprising two compressors (24) configured to compress the tracer gas to a pressure of 500 to 1000 bar, and / or comprising two vaporizers (22).
10. The installation (10) as claimed in any one of claims 8 and 9, wherein: The cold head of the pump (20) comprises means for circulating liquefied gas from the source (16) of liquefied gas.
11. The facility (10) according to any one of claims 8 to 10, further comprising a gas analyzer (50) arranged downstream of the buffer vessel (26) and upstream of the high-pressure vessel (12) to be inspected.
12. The facility (10) according to any one of claims 8 to 11, further comprising a conduit for injecting the liquefied gas from the liquefied gas source (16) into the boil-off liquefied gas.