Mobile device for analyzing a gaseous flow, in particular of hydrogen, in a distribution station

Abstract

The invention relates to a device (1) for analyzing a composition of a gaseous flow, the device comprising: • a spectroscopy module (2) provided with an infrared spectrometer; • an auxiliary module (3) comprising: o a pump (9); and o a calibration cylinder (18); • a protective enclosure (25); the spectroscopy module (2) and the auxiliary module (3) being arranged in the protective enclosure (25), the protective enclosure (25) being configured to isolate the spectroscopy module (2) and the auxiliary module (3) from an environment external to the protective enclosure (25), wherein one of the spectroscopy module (2) and the auxiliary module (3) is configured to attenuate the transmission of vibrations originating from the auxiliary module (3) to the spectroscopy module (2).

Description

[0001] Mobile device for analyzing a gas flow, particularly hydrogen, in a distribution station

[0002] TECHNICAL FIELD

[0003] This disclosure relates to the field of gas stream purity analysis, specifically of gaseous hydrogen. More specifically, it concerns a hydrogen quality analysis device that can be easily deployed in hydrogen refueling stations for road vehicles powered by hydrogen fuel cells.

[0004] STATE OF THE ART

[0005] The rise of hydrogen-powered vehicles has brought new challenges related to their energy supply. These vehicles are powered by hydrogen fuel cells and a mobile hydrogen tank, which can be refilled at dedicated stations. Hydrogen fuel cells convert the chemical energy of hydrogen directly into electricity, which can then be used to power an electric motor.

[0006] The quality of the hydrogen supplied to the fuel cells—that is, the purity of the hydrogen or the absence of non-hydrogen species in the hydrogen stream—has a considerable impact on vehicle operation. Hydrogen fuel cells contain rare metals whose catalytic activity can be negatively affected by impurities in the hydrogen used to power the cell. Such contaminants can even irreversibly damage the fuel cell, thus reducing the vehicle's lifespan. Therefore, it is desirable to be able to verify the purity of the hydrogen before it is refilled in the tank and distributed to the vehicle's fuel cells.

[0007] Today, hydrogen refueling stations rely on certificates provided by hydrogen producers to ensure satisfactory hydrogen purity. However, impurities are frequently introduced into the hydrogen between its production site and the refueling station. Therefore, the producer's assurance of hydrogen purity is not quantified in real time during its distribution to a vehicle's fuel cell. A proposed solution to this problem is outlined in the ISO 14687 standard: hydrogen samples are taken directly at the refueling station and then sent to a certified laboratory to verify the hydrogen's purity, taking into account any impurities that may have appeared during transport from the production site to the station.However, impurities can also contaminate hydrogen during its circulation within the refueling station itself, or during hydrogen processing before distribution. In this case, the hydrogen impurity is only detected when vehicle malfunctions occur, by which time irreversible damage to the hydrogen fuel cell may have already taken place.

[0008] Attempts have been made to provide hydrogen composition monitoring systems at a refueling station, directly upstream of the hydrogen distribution system supplying a vehicle's fuel cells. However, currently available hydrogen purity monitoring systems include components sensitive to environmental conditions such as humidity, temperature variations, and the presence of vibrations, for example, due to vehicle traffic near the monitoring site. These conditions compromise the reliability of the measurements obtained. Thus, existing systems do not allow for sufficiently reliable continuous measurement of hydrogen composition. Furthermore, deploying a measurement system at a hydrogen refueling station is complex, both in terms of permits for installation and equipment certification, as well as the time required for assembly.

[0009] EXPOSED

[0010] It is therefore desirable to have a control device for the composition of a gaseous hydrogen stream that can be easily deployed at vehicle refueling sites, the control device providing reliable measurements directly upstream of the distribution of the gas to the vehicle.

[0011] To this end, a device for analyzing the composition of a gas stream is proposed, comprising:

[0012] • a spectroscopy module, equipped with an infrared spectrometer comprising a measuring cavity capable of receiving a portion of the gas flow, the infrared spectrometer being capable of being connected to an inerting gas supply,

[0013] • an auxiliary module comprising: o a pump fluidly connected to the measuring cavity and configured to evacuate a gas present in the measuring cavity, and

[0014] o a calibration bottle suitable for filling with a gas having a predefined composition, the calibration bottle being fluidically connected to the measurement cavity of the spectroscopy module, and

[0015] • a protective enclosure, the spectroscopy module and the auxiliary module being disposed in the protective enclosure, the protective enclosure being configured to isolate the spectroscopy module and the auxiliary module from an environment outside the protective enclosure, in which one of the spectroscopy module and the auxiliary module is configured to attenuate the transmission of vibrations from the auxiliary module to the spectroscopy module.

[0016] The separation of the spectroscopy and auxiliary modules, as well as the presence of a protective enclosure, provides the spectrometer with an environment that guarantees accurate measurements, while ensuring a compactness and mobility of the analytical device such that it is suitable for use in a hydrogen supply station.

[0017] According to one embodiment:

[0018] The spectroscopy module comprises a support platform for the infrared spectrometer and a plurality of feet configured to support the support platform vertically above the auxiliary module, or the auxiliary module comprises a support platform and a plurality of feet configured to support the support platform vertically above the spectroscopy module.

[0019] According to one embodiment, each foot of the spectroscopy module is mounted on a wheel and / or each foot of the auxiliary module is mounted on a wheel.

[0020] In one embodiment, the auxiliary module comprises:

[0021] a gas chromatograph configured to receive the portion of the gas stream and to measure, in the portion of the gas stream, a concentration of a gas other than hydrogen, in particular a gas among nitrogen and / or helium and / or argon, and

[0022] A carrier gas cylinder fluidly connected to the chromatograph and suitable for receiving a carrier gas for the chromatograph. In one embodiment, the spectroscopy module comprises a protective housing in which the infrared spectrometer is placed, the infrared spectrometer being separated from an internal wall of the protective housing by a damping material configured to absorb the vibrations transmitted from the auxiliary module to the spectroscopy module, the damping material comprising, for example, a foam.

[0023] According to one embodiment, the spectroscopy module includes a receiving platform for the protective housing adapted to be placed in contact with the support platform via damping pieces, the damping pieces comprising, for example, rubber.

[0024] According to one embodiment, the auxiliary module comprises two calibration bottles fluidly connected to the spectroscopy module, a first calibration bottle being suitable for being filled with a gas comprising hydrogen sulfide and a second calibration bottle being suitable for being filled with a gas not comprising hydrogen sulfide.

[0025] In one embodiment, the device comprises:

[0026] a hydrogen sensor located within the protective enclosure and configured to detect a concentration of hydrogen in a quantity of air present within the protective enclosure, and

[0027] an emergency stop system configured to stop the supply of gas flow to the device and / or to stop a supply of electricity to the device when the hydrogen sensor detects a concentration of hydrogen in the quantity of air present in the protective enclosure greater than a predefined threshold.

[0028] According to one embodiment, the device includes a ventilation system configured to renew a quantity of air present in the protective enclosure.

[0029] According to one embodiment, the protective enclosure comprises:

[0030] a door, in particular a double-leaf door, and / or

[0031] two sections of enclosure, the two sections of enclosure being joined to form part of the protective enclosure. According to one embodiment, the protective enclosure is without openings for pipe passages.

[0032] According to one embodiment, an internal wall of the protective enclosure includes a thermally insulating lining and / or in which the device includes a heat pump.

[0033] A second aspect is proposed: a method for analyzing the composition of a gas stream using an analytical device as described above, the method comprising the following steps:

[0034] a. routing of a portion of the gas flow into the measurement cavity of the infrared spectrometer,

[0035] b. acquisition, by the infrared spectrometer, of a representative measurement of the concentration of a gas in the gas stream,

[0036] c. transmission of the representative measurement of a concentration to an acquisition system, and

[0037] d. purging of the measuring cavity using inerting gas,

[0038] the purging being carried out after the acquisition.

[0039] According to one implementation, the process includes, prior to transport, a calibration of the infrared spectrometer comprising the following steps:

[0040] i. routing of a calibration flow from the calibration bottle into the measurement cavity of the infrared spectrometer,

[0041] ii. acquisition, by the infrared spectrometer, of a calibration measurement representative of a gas concentration in the calibration stream, iii. verification of an infrared spectrometer setting parameter from the calibration measurement, and

[0042] iv. Adjustment of the setting parameter based on the verification.

[0043] A third option is proposed: a kit for manufacturing an analytical device as defined above, comprising the spectroscopy module, the auxiliary module, and the protective enclosure. DESCRIPTION OF FIGURES

[0044] Other goals and benefits will emerge from the following description, which is illustrative and not exhaustive, and in which:

[0045] [Fig. 1] represents the proposed device for analyzing the composition of a gas stream.

[0046] [Fig. 2] represents a spectroscopy module of the analysis device.

[0047] [Fig. 3] represents an auxiliary module of the analysis device.

[0048] [Fig. 4] represents a protective enclosure for the analysis device

[0049] [Fig. 5] represents a top view of a planned location, in a gas distribution station, for the analysis device.

[0050] [Fig. 6] represents a method of analyzing a gas flow implemented using the analysis device.

[0051] In all figures, identical or similar elements are designated by the same reference symbols.

[0052] DETAILED DESCRIPTION OF IMPLEMENTATION METHODS

[0053] The gas flow analysis device 1, illustrated in Figure 1, comprises a plurality of distinct modules assembled together to form the analysis device 1. The analysis device 1 enables the analysis of the composition of a gas flow, typically one consisting primarily of hydrogen in gaseous form, in order to identify the presence of species other than hydrogen within the gas flow. In what follows, reference will be made exclusively to hydrogen, but although this is a preferred application of the present analysis device 1, it is perfectly capable of enabling the analysis of a gas flow where the main gas is another gas. The device 1 is configured and optimized so that it can be deployed within a single day without requiring, for example, a crane.

[0054] The analysis device 1 is primarily composed of a spectroscopy module 2, an auxiliary module 3, and a receiving chamber 25. The spectroscopy module 2 and the auxiliary module 3 are configured to minimize vibration transmission between them as much as possible. More specifically, an isolation structure is defined by modules 2 and 3 (i.e., at least one of them) so as to isolate each module 2 and 3 from vibrations originating from the other module.

[0055] The spectroscopy module 2, shown in Figure 2, includes an infrared spectrometer. The spectroscopy module 2 also includes a frame 13 with a support platform 10 for supporting the infrared spectrometer. In the figures, the infrared spectrometer is not directly visible, being housed within a casing 12. However, the infrared spectrometer can be placed directly on the support platform 10, without the casing 12. The frame 13 includes feet 14 that keep the support platform 10 raised off the ground. Preferably, when the spectroscopy module 2 is placed vertically on the ground, the feet 14 extend vertically on either side of the support platform 10, and a protective barrier 29 formed by crossbars extends between each pair of adjacent feet 14 to protect the spectrometer.Spectroscopy module 2, for example, has dimensions of 940 mm, 830 mm and 1693 mm respectively in the three spatial directions.

[0056] The infrared spectrometer of the spectroscopy module 2 is, for example, a spectrometer marketed by the company AP2E® (Proceas Analyzer), operating on the principle of OFCEAS (Optical Feedback Cavity-Enhanced Absorption Spectroscopy) technology, capable of detecting impurities on the scale of ppm (parts per million) or ppb (parts per billion) such as carbon dioxide CO₂, water H₂O, hydrogen sulfide H₂S and dioxygen O₂ in a stream mainly composed of dihydrogen H₂.

[0057] The infrared spectrometer includes a measuring cavity suitable for receiving a gas stream. By measuring the absorption of infrared radiation by the gas stream passing through the measuring cavity, the spectrometer can determine the concentration of a specific gas in the gas stream, or the concentration of several distinct gases.

[0058] Spectroscopy module 2 includes a data acquisition system configured to acquire concentration measurements of one or more gases, these measurements being obtained by the spectrometer. The data acquisition system can be integrated into the infrared spectrometer itself, or located within spectroscopy module 2, external to the spectrometer. Alternatively, the data acquisition system may be separate from analysis device 1, in which case it can remotely acquire measurements performed by the infrared spectrometer. Analysis device 1 can, through the infrared spectrometer, continuously acquire measurements of a gas stream, in particular a hydrogen stream intended for distribution to vehicles.

[0059] The auxiliary module 3, illustrated in Figure 3, has a similar architecture to that of the spectroscopy module 2: the auxiliary module 3 comprises a frame 19 equipped with a plurality of legs 20 between which extends a platform 30 or a plurality of platforms 30 extending at different levels along the legs 20. The auxiliary module 3 has, for example, dimensions, along the three spatial directions, of 740 mm, 730 mm, and 1436 mm, respectively. The auxiliary module 3 includes a pump 9, fluidically connected to the spectrometer, which allows the gases present in the spectrometer's measuring cavity to be evacuated prior to new measurements, thereby increasing its sensitivity (i.e., its ability to detect the presence of a chemical species in the gas stream, even when it is present only in small quantities).The auxiliary module 3 also includes a calibration bottle 18 connected, or capable of being connected, to the measurement cavity of the infrared spectrometer. The calibration bottle 18 is designed to contain a calibration gas mixture whose precise composition has been optimized for the response range of the spectrometer and is therefore known. In this way, when it is necessary to calibrate the infrared spectrometer, a quantity of calibration gas can be supplied via the calibration bottle 18 to the measurement cavity. If the measurements obtained by the acquisition system do not correspond to the known composition of the calibration gas, adjustment parameters such as the spectrometer calibration factor are adjusted so that the composition of the calibration gas measured by the spectrometer falls within the range of the known composition of the calibration gas, taking into account the uncertainty ranges of each molecule in the mixture.

[0060] In one embodiment, the auxiliary module 3 comprises two separate calibration bottles, configured to receive two distinct calibration gases. A first calibration bottle 18 receives a gas containing hydrogen sulfide (H₂S), while a second calibration bottle 18' receives a gas free of hydrogen sulfide (H₂S). Indeed, for certain applications, it may be desirable for the spectrometer to be able to identify hydrogen sulfide (H₂S) in the gas stream to be analyzed, so the spectrometer must be calibrated to measure this gas. However, hydrogen sulfide (H₂S) is unstable and can react with other species present in the calibration gas; therefore, it is necessary to ensure that at least one of the two calibration bottles contains a gas that remains stable over time.For example, the first calibration cylinder 18 contains dihydrogen H₂ with 1 ppm of hydrogen sulfide H₂S, while the second calibration cylinder 18' contains a gas with 80 ppm dioxygen O₂, 40 ppm water H₂O, and 40 ppm carbon dioxide CO₂, the remainder of the calibration gas being dihydrogen H₂. For example, calibration cylinders 18 and 18' are standard 10 L cylinders of gas at a pressure of 200 bar.

[0061] To allow for the scanning of the measurement cavity and the purging of gases present in the cavity and lines during servicing, for example, the infrared spectrometer is connected to a source of inerting gas, typically nitrogen (N2). Nitrogen is continuously supplied from the inerting cylinder to the measurement cavity between two separate gas flow measurements, ensuring that the measurement cavity is empty before the introduction of the gas flow to be analyzed, thus preventing measurements from being distorted by residual gas from a previous measurement. Nitrogen (N2) itself does not distort the measurements, as the infrared spectrometer does not measure the concentration of this gas.

[0062] Advantageously, the auxiliary module 3 includes a chromatograph 5, which allows the presence in the analyzed gas stream of species that cannot be identified by the infrared spectrometer, particularly inert gases such as nitrogen (N2), argon (Ar), and helium (He). The chromatograph is, in particular, the micro GC 990 type marketed by Agilent®. The carrier gas cylinder 7 for the chromatograph 5 is connected to the auxiliary module 3, so as to supply the chromatograph with a carrier gas that transports the analyzed gas stream. The carrier gas passes continuously through a column of the chromatograph 5. Dihydrogen (H2) is used as the carrier gas, which serves as the reference against which the chromatograph 5 is based for detecting the presence of foreign species. The carrier gas is, in particular, scientific hydrogen (H2).Preferably, the auxiliary module includes two carrier gas cylinders 7, a switching device enabling the chromatograph 5 to automatically switch from a first carrier gas cylinder to a second carrier gas cylinder when it is detected that the first cylinder is empty.

[0063] One of the spectroscopy module 2 and the auxiliary module 3 includes an isolation structure designed to eliminate, or at least minimize as much as possible, the transmission of vibrations from the auxiliary module 3 to the spectroscopy module 2. This is because the pump 9 of the auxiliary module 3 generates vibrations during its operation. To obtain the most accurate measurements possible from the spectrometer, the spectrometer's optical components must not be subjected to vibrations. In particular, the spectrometer's laser must be precisely aligned, and this laser alignment can be compromised by a vibratory environment affecting the spectrometer.As shown in Figures 1 to 3, which correspond to a particular embodiment of the isolation structure, the isolation structure is formed by the frame 13 of the spectroscopy module: the platform 10 is positioned at a height such that the auxiliary module 3 can be placed entirely beneath the platform 10, with the feet 14 of the spectroscopy module 2 arranged around the auxiliary module 3 without direct contact between themselves and the feet 20 of the auxiliary module (or, generally, without any direct contact between the two modules 2 and 3). Specifically, each of the spectroscopy module 2 and the auxiliary module 3 comprises three or four feet. The feet 14 of the spectroscopy module can be mounted on casters 17 and the feet 20 of the auxiliary module 3 can be mounted on casters 33, thus minimizing the transmission of vibrations from the ground to the feet 14 and 20.

[0064] According to an alternative embodiment, not shown in the figures, the support platform 10 of the spectroscopy module 2 is instead arranged in the lower part of the feet 14, the platform(s) 30 of the auxiliary module 3 being arranged at a height of the feet 20 of the auxiliary module 3 so that the entire spectroscopy module 2 can be placed below the lowest platform 30, without any direct contact between the two modules 2, 3.

[0065] For both embodiments, a compact arrangement of modules 2 and 3 is achieved, as they occupy the same footprint, while avoiding contact between the two modules 2 and 3 to minimize the transmission of vibrations between them. Such an arrangement is particularly well-suited for forming a mobile analysis unit 1, each of the two modules being able to be transported independently to a hydrogen refueling station for vehicles. Furthermore, the proposed isolation structure has the advantage that, for both of the aforementioned embodiments, it is possible to assemble the spectroscopy module 2 to the auxiliary module 3 in any order, as these two modules 2 and 3 occupy the same floor space but not the same vertical space above the ground.

[0066] The analysis device 1, using the infrared spectrometer and optionally the chromatograph 5, can continuously acquire measurements on a gas stream, particularly a hydrogen stream intended for distribution to vehicles. Due to its compact and mobile design, the analysis device 1 can easily be installed in a hydrogen vehicle refueling station, enabling continuous verification of the hydrogen's purity before it is distributed to vehicles.

[0067] In the spectroscopy module 2, the spectrometer is housed in a dedicated enclosure 12. Preferably, the inner wall of the enclosure 12 is not in direct contact with the spectrometer, but includes a coating or material that helps isolate the spectrometer from vibrations transmitted to the enclosure 12. For example, the enclosure 12 may include foam, for instance, 30 mm thick. This ensures the stability of the spectrometer during transport to a hydrogen refueling station, or from one refueling station to another. This also helps isolate the spectrometer from vibrations generated by the auxiliary module 3.

[0068] The chromatograph 5 can be placed on one of the platforms 30 of the auxiliary module 3 with a foam placed between the chromatograph 5 and the platform 30, so as to also minimize vibrations transmitted by other components of the auxiliary module 3 - in particular, by the pump 9 - to the chromatograph 5. Indeed, although less sensitive to vibrations than the spectrometer, the accuracy of measurements obtained by the chromatograph 5 can be degraded by vibrations of excessive amplitude.

[0069] Additionally, in order to further minimize the vibrations transmitted to the spectrometer by the auxiliary module 3, the spectroscopy module 2 includes a support platform 11 on which the spectrometer housing 12 is placed, the platform 11 itself being arranged on the platform 10 by means of damping pieces 16 made of rubber or of a material capable of attenuating vibrations.

[0070] In addition to the spectroscopy module 2 and the auxiliary module 3, the analysis device 1 includes a protective enclosure 25, shown in Figure 4. The protective enclosure 25 is configured to accommodate the spectroscopy module 2 and the auxiliary module 3 when the two modules 2 and 3 are placed one above the other as described previously. The protective enclosure 25 is capable of completely isolating the modules 2 and 3 from an external environment by covering them. The protective enclosure 25 does not have a solid bottom but comprises four side walls and a roof, as well as a bottom opening 31, so as to completely cover the modules 2 and 3 placed on any type of ground at a power station. The device is independent of the station's ground surface and can be adapted to concrete or gravel.Thus, the protective enclosure 25 reduces the temperature and humidity variations or inclement weather to which the equipment of the spectroscopy module 2 and the auxiliary module 3 are subjected. In particular, the spectrometer is especially sensitive to such temperature or humidity variations, which can result, for example, from seasonal changes or inclement weather. Preferably, the protective enclosure 25 has walls whose internal surface facing modules 2 and 3 is covered with a thermally insulating coating, for example, a 50 mm thick polystyrene coating. This coating can also be corrosion-resistant to protect the internal surfaces of the walls of the protective enclosure 25.

[0071] In order to allow active temperature control in the protective enclosure 25, the analysis device may also include a heat pump.

[0072] The protective enclosure is configured, thanks to the insulating coating and possibly the heat pump, to maintain a temperature of 25°C to 30°C and a humidity level between 40% and 60% in the protective enclosure 5.

[0073] Prior to assembly, the protective enclosure is divided into a plurality of enclosure portions 27 configured to be assembled together. In this way, the different enclosure portions 27 can be transported to the power station independently of each other, each enclosure portion 27 being light enough to be handled by one person without a moving device such as a crane which would require a work permit, thus facilitating the mobility and deployment of the analysis device 1.

[0074] During the assembly of the analysis device 1, the protective enclosure 25 is placed on the modules 2 and 3 via the bottom opening 31. Alternatively, the protective enclosure 25 includes a double-leaf door 26 to allow the modules 2 and 3 to be inserted into the protective enclosure 25, which is already positioned on the ground. No openings are provided in the side walls or roof of the protective enclosure 25: the various conduits or power supplies required to power the components of modules 2 and 3 pass through the bottom opening 31, thus ensuring that the thermal integrity of the protective enclosure 25 is not compromised. Seals are provided around the door 26.

[0075] Referring to Figure 5, which illustrates a footprint 21 occupied by the analysis device 1, the protective enclosure 25 can be positioned, via the bottom opening 31, directly onto an aluminum slab 32 whose dimensions are twice those of the bottom opening 31. This aluminum slab 32 is placed and screwed onto rectangular blocks arranged on a leveled surface to maintain the stability of the assembly. The aluminum slab 32 may include rails 34 to guide the rollers 17, 33 of the two modules 2, 3. The aluminum slab 32 itself provides isolation for the spectroscopy module 1 from vibrations originating outside the protective enclosure 25, which could be transmitted through the ground.

[0076] To prevent the accumulation of hydrogen in the protective enclosure 25 in the event of a leak, the analysis device 1 includes a hydrogen sensor 28. When the hydrogen sensor 28 detects a quantity of hydrogen in the air exceeding a predefined threshold, an emergency shutdown system for the analysis device 1 cuts off the gas flow to the spectrometer and, if applicable, to the chromatograph 5. The emergency shutdown system can also cut off the power supply to the components of modules 2 and 3. This prevents the formation of potentially explosive atmospheres (known as "ATEX" zones) within the analysis device 1. In one embodiment, the emergency shutdown system cuts off the gas flow when the hydrogen concentration exceeds 8000 ppm, but only cuts off the power supply when the hydrogen concentration exceeds 16000 ppm.This allows, initially, to mitigate the consequences of the leak while maintaining the acquisition of measurements on the gas flow and, secondly, when the hydrogen concentration becomes more critical, to minimize as much as possible the risk of an explosion.

[0077] According to some embodiments, the spectrometry module 2 comprises several infrared spectrometers and / or the auxiliary module 2 comprises several chromatographs 5. In particular, the different spectrometers or chromatographs 5 can be configured to detect different species in the gas stream.

[0078] The analysis device 1 includes a ventilation system with at least one inlet for introducing outside air, heated to the correct temperature by a heat pump (e.g., 20°C), into the protective enclosure 25, and one outlet for expelling air from the protective enclosure 25 to the outside. The ventilation system helps prevent the formation of explosive zones within the protective enclosure 25 and maintains a constant temperature within the enclosure.

[0079] The aluminum slab 32, which houses the analysis device 1, may include a receiving area 22, designed to accommodate the analysis device 1, as well as a support area 23 on which an operator can stand to perform operations on the analysis device 1, for example, to insert or remove a module 2, 3 from the protective enclosure 25 without moving the enclosure itself. Indeed, in some hydrogen refueling stations, the analysis device 1 may be placed on gravel or sand, and the presence of the aluminum slab 32 therefore contributes to the operator's comfort and safety.

[0080] A method for obtaining measurements on the gas flow is shown in Figure 6. Before a measurement, the operator first checks that the analysis device 1 is free of nitrogen leaks and then hydrogen leaks. Next, they verify that the hydrogen flow pressure is adequately regulated to allow measurements by the analysis device 1 – indeed, the flow intended for distribution to a vehicle must have a pressure between 450 and 700 bar depending on the vehicle type, while the analysis device 1 is configured to analyze a gas flow at an absolute pressure between 1.5 and 2 bar, which is equivalent to 0.5 to 1 bar.The gas flow to be analyzed therefore comes from an expansion of the flow to be distributed to the vehicles, this expansion being carried out outside the analysis device 1 by means of a pressure regulation system which decreases by a first two-stage step from 500 to 30 bar and by a second one-stage step from 30 to 0.86 bar.

[0081] When the analysis device 1 has previously been used for data acquisition, the operator purges the various pipes connected to the spectrometer and the spectrometer's measuring cavity with nitrogen (N₂) from the inerting cylinder. However, this step may be omitted when there is no risk of gas remaining in the pipes or the spectrometer, for example, during the first use of the analysis device 1, or when sufficient time has elapsed for such a risk to have been eliminated.

[0082] Prior to acquiring new measurements, when there is doubt as to whether the spectrometer is precisely calibrated, the measurement procedure 100 includes a calibration phase 200. The operator (step 101) directs a calibration flow from a calibration bottle 18, 18' to the spectrometer's measuring cavity, the composition of the calibration gas being precisely known, and acquires (step 102) representative measurements of the calibration gas composition using the spectrometer. Then, the operator verifies (step 103) that the spectrometer's calibration parameters are correct, i.e., that the composition of the calibration flow measured by the spectrometer is identical to the known composition of the calibration flow.If this verification reveals that one or more spectrometer settings are incorrect, the operator adjusts (step 104) these settings to ensure consistency between the measured composition and the known composition of the calibration stream. The procedure 100 includes, either after the calibration phase 200 or independently of it when there is no doubt that the spectrometer is correctly calibrated, an analysis phase, with a step 105 of conveying a gas stream to be analyzed to the spectrometer's measuring cavity, a step 106 of acquiring concentration measurements in the gas stream, and a step 107 of transmitting the obtained measurements to the acquisition system.

[0083] The pipes of the analysis device 1 can naturally include remotely operated valves, so as to allow the various stages of the analysis process 100 to be carried out by an operator or a remote automaton.

Claims

DEMANDS 1. Device for analyzing the composition of a gas stream, comprising: • a spectroscopy module (2), equipped with an infrared spectrometer comprising a measuring cavity suitable for receiving a portion of the gas flow, the infrared spectrometer being suitable for being connected to an inerting gas supply, • an auxiliary module (3) comprising: o a pump (9) fluidly connected to the measuring cavity and configured to evacuate a gas present in the measuring cavity, and o a calibration bottle (18) capable of being filled with a gas having a predefined composition, the calibration bottle (18) being fluidly connected to the measuring cavity of the spectroscopy module (2), and • a protective enclosure (25), the spectroscopy module (2) and the auxiliary module (3) being arranged in the protective enclosure (25), the protective enclosure (25) being configured to isolate the spectroscopy module (2) and the auxiliary module (3) from an environment external to the protective enclosure (25), in which one of the spectroscopy module (2) and the auxiliary module (3) is configured to attenuate the transmission of vibrations from the auxiliary module (3) to the spectroscopy module (2).

2. Device (1) according to claim 1, wherein: the spectroscopy module (2) includes a support platform (10) for the infrared spectrometer and a plurality of feet (14) configured to support the support platform (10) vertically above the auxiliary module (3), or the auxiliary module (3) includes a support platform (30) and a plurality of feet (20) configured to support the support platform (30) vertically above the spectroscopy module (2), 3. Device (1) according to claim 2, wherein each foot (14) of the spectroscopy module (2) is mounted on a wheel (17) and / or each foot (20) of the auxiliary module (3) is mounted on a wheel (33).

4. Device (1) according to any one of claims 1 to 3, wherein the auxiliary module (3) comprises: a gas chromatograph (5) configured to receive the portion of the gas stream and to measure, in the portion of the gas stream, a concentration of a gas other than hydrogen, in particular a gas among nitrogen and / or helium and / or argon, and a carrier gas cylinder (7) fluidically connected to the chromatograph (5) and suitable for receiving a carrier gas for the chromatograph (5).

5. Device (1) according to any one of claims 1 to 4, wherein the spectroscopy module comprises a protective housing (12) in which the infrared spectrometer is disposed, the infrared spectrometer being separated from an internal wall of the protective housing (12) by a damping material configured to absorb the vibrations transmitted by the auxiliary module (3) to the spectroscopy module (2), the damping material comprising, for example, a foam.

6. Device (1) according to claim 5, wherein the spectroscopy module (2) includes a receiving tray (11) of the protective housing (12) adapted to be disposed in contact with the support platform (10) by means of damping parts (16), the damping parts (16) comprising for example rubber.

7. Device (1) according to any one of claims 1 to 6, wherein the auxiliary module (3) comprises two calibration bottles (18) fluidly connected to the spectroscopy module (2), a first calibration bottle (18) being able to be filled with a gas comprising hydrogen sulfide and a second calibration bottle (18) being able to be filled with a gas not comprising hydrogen sulfide.

8. Device (1) according to any one of claims 1 to 7, comprising: a hydrogen sensor (28) disposed in the protective enclosure (25) and configured to detect a concentration of hydrogen in a quantity of air present in the protective enclosure (25), and an emergency shutdown system configured to stop the supply of gas flow to the device (1) and / or to stop the supply of electricity to the device (1) when the hydrogen sensor (28) detects a hydrogen concentration in the quantity of air present in the protective enclosure exceeding a predefined threshold.

9. Device (1) according to any one of claims 1 to 8, comprising a ventilation system configured to renew a quantity of air present in the protective enclosure (25).

10. Device (1) according to any one of claims 1 to 9, wherein the protective enclosure (25) comprises: a door (26), in particular a double-leaf door, and / or two enclosure portions (27), the two enclosure portions (27) being assembled to form part of the protective enclosure (25).

11. Device (1) according to any one of claims 1 to 10, wherein the protective enclosure (25) is devoid of a pipe passage opening.

12. Device (1) according to any one of claims 1 to 11, wherein an internal wall of the protective enclosure (25) comprises a thermally insulating coating and / or wherein the device (1) comprises a heat pump.

13. A method for analyzing (100) the composition of a gas stream using an analytical device (1) according to any one of claims 1 to 12, the method comprising the steps of: a. routing (105) of a portion of the gas flow into the measurement cavity of the infrared spectrometer, b. acquisition (106), by the infrared spectrometer, of a representative measurement of a gas concentration in the gas stream, c. transmission (107) of the representative measurement of a concentration to an acquisition system, and d. purging of the measuring cavity using inerting gas, the purging being carried out after the acquisition.

14. Analytical method according to claim 13, comprising, prior to shipment, a calibration (200) of the infrared spectrometer comprising the steps of: i. routing (101) of a calibration stream from the calibration bottle (18) into the measurement cavity of the infrared spectrometer, ii. acquisition (102), by the infrared spectrometer, of a calibration measurement representative of a gas concentration in the calibration stream, iii. verification (103) of an infrared spectrometer adjustment parameter from the calibration measurement, and iv. adjustment (104) of the setting parameter based on the verification.

15. Kit for manufacturing an analytical device according to any one of claims 1 to 12, comprising the spectroscopy module (2), the auxiliary module (3) and the protective enclosure (25).

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