Hydrogen conversion device, measuring device, calibration method, and installation comprising such a device.

Abstract

Device (100) for converting ortho hydrogen into para hydrogen comprising a sampling conduit (15) having an upstream end configured to be connected to a cold hydrogen source at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K, the sampling conduit (15) comprising at least one catalysis section (17) for the hydrogen sampled by the sampling conduit (15), the catalysis section (17) having a quantity of catalyst configured to ensure a conversion of ortho hydrogen into para hydrogen up to the ortho / para equilibrium composition corresponding to the determined temperature, the device comprising a thermal insulator (14) arranged on the sampling conduit (15) encompassing the upstream end and the catalysis section (17). Abstract figure: Fig. 1

Description

Title of the invention: Hydrogen conversion device, measuring apparatus, calibration method, and installation comprising such an apparatus.

[0001] The present invention relates to a device for converting ortho hydrogen into para hydrogen, an apparatus for measuring the ortho / para composition of hydrogen, a method for calibrating the apparatus and an installation comprising the apparatus.

[0002] The invention relates more particularly to a device for converting ortho hydrogen into para hydrogen comprising a sampling conduit having an upstream end configured to be connected to a cold hydrogen source at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K.

[0003] Hydrogen is composed of two isomers: the ortho-hydrogen (ortho) form and the para-hydrogen (para) form. The equilibrium proportion of hydrogen molecules between its ortho and para form varies with temperature. At room temperature, the composition is 75% ortho, 25% para, while at liquid hydrogen temperature (+ / -20K), the composition is close to 100% para. Thus, during the liquefaction process, a conversion of ortho hydrogen to para takes place. This conversion is exothermic (about 700kJ / kg) and therefore can be responsible for the evaporation of the liquefied hydrogen; the heat of vaporization is close to 454kJ / kg. On the other hand, the natural conversion reaction kinetics is very slow (time scale: days / weeks) and therefore to avoid natural conversion in liquid storage and associated evaporation, it is necessary to add a catalyst in the liquefaction process to accelerate the conversion.Since the ortho / para composition plays a key role in the liquefaction process, it must be monitored and ensure the final concentration at the outlet of the liquefier.

[0004] Several technologies exist for measuring the ortho / para proportion. The TCD, thermal conductivity detector (“Thermal Conductivity Detector”) is frequently used due to its simplicity of implementation and its low cost. But its operating principle presents a major problem with regard to the reliability and precision of the results obtained. Indeed, the TCD measurement is based on the difference in conductivity between the ortho and para forms of hydrogen. The thermal conductivity of the ortho and para mixture is a linear composition of the conductivities of the ortho and para forms.

[0005] Since the sum of the ortho and para fractions is equal to 1, the relationship between the thermal conductivity of the mixture is a linear function of the para composition. To calibrate the TCD, it is necessary to have at least two calibration points. These calibration points must be of precisely known composition. The first calibration point is fairly easy to obtain using hydrogen at room temperature; its composition is close to 75% ortho, 25% para. However, the second calibration point is more complicated to obtain reliably.

[0006] There are three methods to obtain this second calibration point.

[0007] The first method proposes to circulate a flow of hydrogen in a volume of excess catalyst immersed in a bath of liquid nitrogen. This system has the advantage of simplicity of implementation, however it seriously lacks precision. On the one hand because the model which allows the theoretical value of the ortho / para composition to be calculated close to the temperature of liquid nitrogen has a high uncertainty (greater than 1% of the composition). This de facto generates an uncertainty on the analysis tool of 3% on the full scale.

[0008] The second method is similar to the first method but works with a "cryocooler", otherwise called a "cryogenic cooler", allowing temperatures to drop below 30K. The advantage is that the uncertainty linked to the theoretical composition is minimized, in addition to performing a calibration with a point on the full measurement scale. On the other hand, such an independent system is very expensive and requires complex implementation.

[0009] The third method is to use already liquefied hydrogen from cryogenic storage. The advantage of this method is its simplicity and low cost. The disadvantage is that it is impossible to certify the conversion rate of this liquid hydrogen.

[0010] The present invention aims to overcome all or part of the drawbacks of the prior art noted above.

[0011] To this end, the device according to the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that the sampling conduit comprises at least one catalysis section for the hydrogen sampled by the sampling conduit, the catalysis section having a quantity of catalyst configured to ensure a conversion of the ortho hydrogen into para hydrogen up to the ortho / para equilibrium composition corresponding to the determined temperature, the device comprising a thermal insulator arranged on the sampling conduit encompassing the upstream end and the catalysis section.

[0012] According to one embodiment, the sampling conduit comprises a heating section downstream of the catalysis section which is located outside the thermal insulation.

[0013] The invention further relates to an apparatus for measuring the ortho / para composition of hydrogen comprising an analyzer configured to measure the relative proportions of ortho and para hydrogen in hydrogen, the analyzer being of the type capable of being calibrated and / or verified by at least one reference measurement of hydrogen at a proportion of ortho and para hydrogen, the apparatus comprising a calibration and / or verification device comprising the device for converting ortho hydrogen into para hydrogen as described above, said sampling conduit comprising a downstream end configured to be connected to the analyzer, the hydrogen converted by the catalysis section constituting a reference measurement for calibration and / or verification of the analyzer.

[0014] According to one embodiment, the calibration and / or verification device comprises a sampling conduit having an upstream end configured to be connected to a source of hydrogen at a temperature higher than the determined temperature, preferably at ambient temperature, and at a corresponding ortho / para proportion and a downstream end configured to be connected to the analyzer to supply it with hydrogen in order to provide a second calibration and / or verification reference measurement and / or in order to measure the relative proportions of ortho and para hydrogen.

[0015] According to one embodiment, the calibration and / or verification device comprises a source of hydrogen cooled to a determined temperature less than or equal to 80 K, in particular to a temperature less than or equal to 30 K.

[0016] The invention further relates to a liquid hydrogen production and / or storage installation comprising a hydrogen storage and / or circuit, the installation comprising a measuring device as described above, characterized in that the hydrogen storage and / or circuit comprises at least one sampling portion which contains hydrogen at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K, and in that the upstream end of the sampling conduit is connected to the sampling portion.

[0017] According to one embodiment, the installation comprises a hydrogen circuit, the hydrogen circuit having an upstream end intended to be connected to a device for supplying gaseous hydrogen and a downstream end intended to be connected to at least one member for collecting liquefied hydrogen, the installation comprising a set of heat exchanger(s) in heat exchange with the hydrogen circuit and a cooling system in heat exchange with at least part of the set of heat exchanger(s), said cooling system comprising a refrigerator with a refrigeration cycle of a cycle gas comprising helium and / or hydrogen, and said hydrogen circuit comprising at least one catalysis section configured to ensure a conversion of ortho hydrogen into para hydrogen.

[0018] According to one embodiment, the upstream end of the sampling conduit is connected to a portion of the sample located at the level of the hydrogen circuit, downstream of one or more heat exchangers, in particular downstream of the set of heat exchanger(s).

[0019] According to one embodiment, the installation comprises a liquefied hydrogen collection member, for example a cryogenic storage and / or a separator pot, the upstream end of the sampling conduit being connected to a portion of the sampling located at the level of the liquefied hydrogen collection member.

[0020] According to one embodiment, the installation comprises a set of valve(s) configured to control the flow of hydrogen circulating in the sampling conduit.

[0021] According to one embodiment, the analyzer comprises a plurality of measurement inputs configured to receive respective hydrogen flows taken from different locations in the installation.

[0022] According to one embodiment, the installation comprises a measuring device as described above, characterized in that the upstream end of the sampling conduit is connected to the hydrogen circuit or to another gaseous storage of the installation containing hydrogen at a temperature higher than the determined temperature, preferably at ambient temperature and having an ortho / para proportion corresponding to this temperature.

[0023] According to one embodiment, the installation comprises a measuring conduit having an upstream end connected to the hydrogen circuit and a downstream end connected to the analyzer in order to measure the relative proportions of ortho and para hydrogen of the hydrogen sampled.

[0024] According to one embodiment, the sampling conduit comprises at least one member for measuring and / or adjusting the pressure and / or the temperature and / or the flow rate of the hydrogen, said member being located for example downstream of said at least one catalysis section.

[0025] According to one embodiment, the hydrogen circuit comprises, downstream of the heat exchanger(s) assembly, a hydrogen expansion turbine, the upstream end of the sampling conduit being connected to the inlet or outlet of the expansion turbine, i.e. the sampling portion is located at the inlet or outlet of the turbine.

[0026] According to one embodiment, the hydrogen circuit comprises, after the outlet of the expansion turbine, an additional passage in at least one heat exchanger of the set of heat exchanger(s), the upstream end of the sampling conduit being connected to the hydrogen circuit upstream or downstream of the additional passage in at least one heat exchanger, that is to say that the sampling portion is located at the level of the hydrogen circuit upstream or downstream of the additional passage in at least one heat exchanger.

[0027] According to one embodiment, the installation comprises a set of filling pipe(s) having an upstream end connected to the collection member or connected directly to the downstream end of the hydrogen circuit and a downstream end intended to be connected to a liquid hydrogen tank to be filled with liquid hydrogen, and in that the upstream end of the sampling pipe is connected to the filling pipe(s), that is to say that the sampling portion is located at the level of the filling pipe(s).

[0028] According to one embodiment, the installation comprises a set of vaporization gas recovery pipe(s) having a first end intended to be connected to a liquid hydrogen tank to be filled and a second end connected to a receiving member of the installation, for example the collection member, and in that the upstream end of the sampling pipe is connected to the recovery pipe, that is to say that the sampling portion is located at the level of the vaporization gas recovery pipe(s).

[0029] The invention further relates to a method for calibrating and / or verifying a measuring device as described above, or the measuring device of an installation as described above, the method comprising: - a sample of hydrogen cooled at a hydrogen source at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K, - a conversion of the cooled hydrogen taken ortho into para hydrogen up to the ortho / para equilibrium proportion corresponding to the determined temperature, by bringing the cooled hydrogen taken into contact with the at least one catalysis section, - supplying the analyzer with converted hydrogen as a reference measurement for calibration and / or verification of the analyzer.

[0030] According to one embodiment, the method comprises: - a withdrawal of hydrogen from a hydrogen source at a temperature higher than the determined temperature, preferably at ambient temperature, - supplying the analyzer with hydrogen taken at a temperature higher than the temperature determined as a reference measurement for calibration and / or verification of the analyzer.

[0031] According to one embodiment, the cooled hydrogen is taken from a liquid hydrogen production and / or storage facility as described above.

[0032] According to one embodiment, the method comprises: - before the sampling of cooled hydrogen, a step of connecting the downstream end of the sampling conduit to the analyzer, - after supplying the analyzer with converted hydrogen, a step of disconnecting the downstream end of the analyzer sampling conduit.

[0033] The invention may also relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

[0034] Other features and advantages will appear on reading the description below, given with reference to the figures in which:

[0035] [Fig.l] represents a schematic and partial view illustrating an exemplary embodiment of the structure and operation of a device according to the invention,

[0036] [Fig.2] represents a schematic and partial view illustrating an example of a rea structural and operational development of an apparatus according to the invention,

[0037] [Fig.3] represents a schematic and partial view illustrating a first example of construction of the structure and operation of an installation according to the invention,

[0038] [Fig.4] represents a schematic and partial view illustrating a second example of construction of the structure and operation of an installation according to the invention,

[0039] [Fig.5] represents a schematic and partial view illustrating a third example of construction of the structure and operation of an installation according to the invention,

[0040] [Fig.6] represents a schematic and partial view illustrating a fourth example of construction of structure and operation of an installation according to the invention,

[0041] [Fig.7] represents a schematic and partial view illustrating a fifth example of the construction of the structure and operation of an installation according to the invention,

[0042] [Fig.8] represents a schematic and partial view illustrating a sixth example of the structure and operation of an installation according to the invention,

[0043] [Fig.9] represents a schematic and partial view illustrating a seventh example of construction of the structure and operation of an installation according to the invention,

[0044] [Fig. 10] represents a schematic and partial view illustrating an eighth example of embodiment of structure and operation of an installation according to the invention,

[0045] [Fig. 11] represents a schematic and partial view illustrating a ninth example of embodiment of structure and operation of an installation according to the invention,

[0046] [Fig. 12] represents a schematic and partial view illustrating a tenth example of embodiment of structure and operation of an installation according to the invention,

[0047] [Fig. 13] represents a schematic and partial view illustrating an eleventh example of embodiment of structure and operation of an installation according to the invention,

[0048] [Fig. 14] represents a schematic and partial view illustrating a twelfth example of embodiment of structure and operation of an installation according to the invention,

[0049] [Fig. 15] represents a schematic and partial view illustrating a thirteenth example of the structure and operation of an installation according to the invention,

[0050] [Fig. 16] represents a schematic and partial view illustrating a fourteenth example of the structure and operation of an installation according to the invention,

[0051] In all the figures, the same references refer to the same elements.

[0052] In this detailed description, the following embodiments are examples. Well that the description refers to one or more embodiments, this does not mean that the features apply only to a single embodiment. Single features of different embodiments may also be combined and / or interchanged to provide other embodiments.

[0053] The device 100 for converting ortho hydrogen into para hydrogen comprises a sampling conduit 15 having an upstream end configured to be connected to a source of hydrogen cooled to a determined temperature less than or equal to 80 K, in particular to a temperature less than or equal to 30 K.

[0054] As shown diagrammatically in [Fig.l], the sampling conduit 15 comprises at least one catalysis section 17 for the hydrogen sampled by the sampling conduit 15.

[0055] The catalysis section 17 is configured to ensure a (complete) conversion of ortho hydrogen into para hydrogen at an ortho / para equilibrium proportion corresponding to the temperature of the hydrogen taken.

[0056] The catalysis section 17 may be located at the upstream end of the sampling conduit 15 and may be directly connected to a source of hydrogen cooled to a determined temperature less than or equal to 80 K, in particular to a temperature less than or equal to 30 K, in particular to a temperature less than or equal to 25 K.

[0057] The catalysis section 17 contains an excess quantity or volume of catalyst, i.e. configured to ensure conversion of ortho hydrogen into para hydrogen up to the ortho / para equilibrium composition corresponding to the determined temperature (corresponding to the temperature of the source where the hydrogen is taken). For example, the catalysis section is configured to convert a hydrogen stream initially at a temperature of 25K and having relative ortho / para proportions of 5% / 95% into a converted stream having the proportions 1% / 99%.

[0058] The amount of catalyst can be determined from the kinetic law associated with the catalyst used. A calculation of the catalyst volume can be carried out with a sufficiently large margin (typically greater than 500% of the calculated amount) to compensate for any possible loss of catalyst performance. This catalyst volume is typically around ten cm3.

[0059] The device 100 further comprises a thermal insulator 14, for example multi-layer insulation (MLI) or a cold box or a means of a portion of vacuum line or a cryogenic hose, arranged at least on a portion of the sampling conduit 15. The thermal insulator 14 includes the upstream end of the sampling conduit 15 and the catalysis section 17. The insulator thermal 14 allows the withdrawn hydrogen to maintain the same temperature as the cold hydrogen source until the end of the passage in the catalysis section 17 and to ensure minimal heating of the withdrawn hydrogen.

[0060] The thermal insulator 14 may comprise or be part of a cold box encompassing cryogenic devices of a cold hydrogen source, for example of a hydrogen liquefaction installation.

[0061] The sampling conduit 15, in particular the upstream end of the sampling conduit 15 up to the catalysis section 17, is thus insulated to maintain the temperature of the hydrogen sampled.

[0062] The sampling conduit 15 may comprise a heating section 16 downstream of the catalysis section 17 which is placed outside the thermal insulation 14.

[0063] The heating section 16 is configured to heat the converted hydrogen leaving the catalysis section 17 and to supply hydrogen in gaseous form, for example at a temperature greater than or equal to -20°C (more precisely around room temperature), to supply the analyzer 20, in particular a sample conditioning system upstream of the analyzer 20 (not shown). The sample conditioning system may comprise at least one sample inlet (of hydrogen taken, for example at different locations in the installation), a set of valves and a set of pressure reducers necessary for the proper operation of the analyzer 20.

[0064] Section 16 may include a heater, or simply coils or fins for heating the converted extracted hydrogen using ambient heat.

[0065] The apparatus 200 shown in [Fig.2] is an example of an apparatus for measuring the ortho / para composition of hydrogen comprising an analyzer 20. The analyzer 20 is configured to measure the relative proportions of ortho and para hydrogen in the hydrogen.

[0066] The analyzer 20 is of the type that can be calibrated and / or verified by at least one reference measurement of hydrogen at a proportion of ortho and para hydrogen.

[0067] The first reference measurement for calibration and / or verification of the analyzer 20 is preferably taken from hydrogen at a temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K, in particular at a temperature less than or equal to 25 K.

[0068] The analyzer 20 may be of the type that can be calibrated and / or verified by at least two reference measurements of hydrogen at respective proportions of ortho and para hydrogen, one reference measurement being a relatively high para content (close to 100% para) and the other reference measurement being a relatively low para content (75% ortho and 25% para). For example, a first reference measurement is taken from hydrogen sampled at a temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K, in particular at a temperature less than or equal to 25 K (corresponding to a reference measurement with a relatively high para content) and a second reference measurement is taken from hydrogen taken at room temperature (corresponding to a reference measurement with a relatively low para content (75% ortho and 25% para)).

[0069] For example, the analyzer is a thermal conductivity detector (“TCD” or “Thermal Conductivity Detector”).

[0070] The apparatus 200 comprises a calibration and / or verification device comprising the device 100 for converting ortho hydrogen into para hydrogen as described above.

[0071] The sampling conduit 15 comprises a downstream end configured to be connected to the analyzer 20, in particular in a removable / pluggable manner. The downstream end of the sampling conduit 15 may be part of a heating section 16. Thus, the downstream end of the sampling conduit 15 is placed outside the thermal insulator 14 and configured to supply the analyzer 20 with the hydrogen converted into gaseous form.

[0072] In particular, the downstream end of the sampling conduit 15 is connected to the analyzer 20 during calibration and / or verification of the analyzer 20. Thus, the sampled hydrogen is first brought into contact with at least one catalysis section 17 and then supplied to the analyzer 20 as a first reference measurement for calibration and / or verification of the analyzer 20 with an equilibrium composition of ortho / para hydrogen corresponding to the temperature of the cooled hydrogen source (the determined temperature).

[0073] For example, the upstream end and / or the downstream end is provided with a removable connection system allowing non-permanent (removable) connection, for example of the quick coupling type.

[0074] The quantity of catalyst in the catalysis section 17 is for example determined from the flow rate of hydrogen sampled necessary to send to the analyzer 20 (typically of the order of tens of g / h) and the kinetic law associated with the catalyst used. From these two conditions, a calculation of the volume of catalyst is carried out with a sufficiently large margin (typically greater than 500% of the calculated quantity) to compensate for any loss of performance of the catalyst. This volume of catalyst is typically of the other tens of cm3.

[0075] The hydrogen converted by the catalysis section 17 constitutes a reference measurement for calibration and / or verification of the analyzer 20, corresponding to a relatively high proportion of para hydrogen.

[0076] By “calibrating the analyzer” is meant measuring a known hydrogen composition and changing parameters in the analyzer so that the measurement obtained by the analyzer corresponds to the known hydrogen composition.

[0077] By “analyzer verification” is meant measuring a known hydrogen composition and verifying that the analyzer actually measures the known composition.

[0078] Calibration or verification may consist of modifying or verifying the measurement accuracy of the analyzer.

[0079] The calibration and / or verification device may comprise a sampling conduit 21 having an upstream end configured to be connected to a hydrogen source at a temperature higher than the determined temperature and at an ortho / para proportion corresponding to this temperature. Preferably, the upstream end of the sampling conduit 21 is configured to be connected to the hydrogen source at the ambient temperature corresponding to the equilibrium hydrogen composition of 75% ortho and 25% para.

[0080] The sampling conduit 21 has a downstream end configured to be connected to the analyzer 20 to supply it with hydrogen in order to provide a second calibration and / or verification reference measurement and / or in order to measure the relative proportions of ortho and para hydrogen with a relatively low proportion of para hydrogen (75% ortho and 25% para).

[0081] As previously, the upstream end and / or the downstream end may be provided with a removable connection system cooperating with its connection point.

[0082] Preferably, this second calibration and / or verification reference measurement provided to the analyzer 20 corresponds to the hydrogen equilibrium composition of 75% ortho and 25% para (at room temperature).

[0083] The analyzer 20 may comprise one or more measurement inputs in addition to the calibration and / or verification reference measurements mentioned above. This or these measurement input(s) is / are configured to receive respective hydrogen flows in order to determine the relative proportions of ortho / para hydrogen by the analyzer 20 which has been previously calibrated and / or verified by calibration and / or verification reference measurements.

[0084] In one embodiment, the analyzer 20 may be configured to analyze the ortho / para hydrogen proportion of one measurement input at a time. The analyzer 20 switches from one input to the other to make different measurements one after the other.

[0085] In another embodiment, the analyzer 20 may be configured to analyze the ortho / para hydrogen proportions of multiple measurement inputs in parallel.

[0086] The calibration and / or verification device may comprise a source of hydrogen cooled to a determined temperature less than or equal to 80 K, in particular to a temperature less than or equal to 30 K. Thus, the source of cooled hydrogen is connected to the upstream end of the sampling conduit 15 and the insulator thermal 14 encompasses the entire cooled hydrogen source, the upstream end of the sampling conduit 15 and the catalysis section 17.

[0087] The quantity of hydrogen sampled is at least equal to the necessary supply value of the analyzer 20, typically of the order of ten g / h. This quantity is regulated at the level of the analyzer plate which regulates the flow rate sent to the analyzer 20.

[0088] For example, the flow rate of hydrogen sampled by the sampling conduit 15 and sent to the analyzer 20 is between 0.5 and 1.5 liters / minute.

[0089] The source of cooled hydrogen can, for example, come from the liquid-vapor separation pot located upstream of the liquid hydrogen storage.

[0090] Between calibration and / or verification samples, the calibration and / or verification device can be disconnected from the analyzer 20. That is to say that the downstream end of the sampling conduit 15 and / or the downstream end of the sampling conduit 21 are not connected to the analyzer 20.

[0091] Alternatively, when it is no longer necessary to carry out a calibration and / or verification measurement, the downstream end of the sampling conduit 15 may still remain connected to the analyzer 20 and the calibration and / or verification device may comprise an evacuation conduit connected to the sampling conduit 15 downstream of the catalysis section 17 in order to evacuate the flow of hydrogen leaving the catalysis section 17 of the calibration and / or verification device instead of supplying the analyzer 20. The calibration and / or verification device may comprise means, for example one or more valves, for directing the flow of hydrogen leaving the catalysis section 17 towards the evacuation conduit or towards the analyzer 20. This makes it possible to keep the sampling conduit 15, in particular the catalysis section 17, cold, even outside the calibration and / or verification process.

[0092] The installation 300 shown in [Fig. 3] is an example of an installation for producing and / or storing 8 liquid hydrogen comprising a storage 8 and / or a hydrogen circuit 3 to be liquefied and a measuring device 100. The circuit 3 comprises at least one sampling portion which contains hydrogen at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K. The upstream end of the sampling conduit 15 is connected to the sampling portion.

[0093] The installation may comprise at least one device 2 for supplying gaseous hydrogen.

[0094] The hydrogen circuit 3 comprises an upstream end intended to be connected to the device 2 for supplying gaseous hydrogen and a downstream end intended to be connected to at least one member 8 for collecting liquefied hydrogen.

[0095] As shown schematically, the installation 300 comprises a set of exchanger(s) 4, 5, 6, 7 of heat in thermal exchange with the circuit 3 of hydrogen to be cooled.

[0096] The installation 300 comprises at least one cooling system 9 in heat exchange with at least part of the set of heat exchanger(s) and configured to lower the temperature of the hydrogen to be cooled to a determined temperature, less than or equal to 80 K, in particular to a temperature less than or equal to 30 K, more particularly between 15K and 25K.

[0097] The cooling system 9 preferably comprises a refrigerator with a cycle for refrigerating a cycle gas comprising helium and / or hydrogen. This refrigerator comprises, for example, arranged in series in a cycle circuit 10: a mechanism 11 for compressing the cycle gas, at least one member 4, 5, 6, 7 for cooling the cycle gas, a mechanism 12 for expanding the cycle gas (comprising one or more turbines and / or expansion valves) and at least one member 4, 5, 6, 7 for reheating the expanded cycle gas. The compression mechanism preferably comprises several compression stages in series composed of a set of centrifugal and / or piston compressor(s). The expansion mechanism comprises, for example, one or more expansion stages composed of a set of centripetal turbine(s).As illustrated, the cooling system 9 may comprise a pre-cooling system 19 (cryogenic refrigerator or equivalent) in heat exchange with at least part of the heat exchanger assembly 4, 5, 6, 7 and configured to lower the temperature of the hydrogen to be cooled from ambient temperature to a temperature below ambient temperature, for example between 60 and 90K.

[0098] The hydrogen circuit 3 comprises at least one catalysis section 13 configured to ensure a conversion of ortho hydrogen into para hydrogen. As illustrated, several catalysis sections 13 may be provided in series on the hydrogen circuit 3 to be cooled, for example at the level of passages in the heat exchangers 6, 7 and / or in pots outside the heat exchangers.

[0099] As illustrated, the upstream end of the sampling conduit 15 can be connected to a portion of the sampling located at the level of the hydrogen circuit 3. The portion of the sampling can be located downstream of one or more heat exchangers, in particular downstream of the set of heat exchangers 4, 5, 6, 7. Thus, the sampling of hydrogen is carried out at temperature conditions less than or equal to 80 K, in particular at temperature conditions less than or equal to 30 K.

[0100] The hydrogen taken at this temperature is brought into contact with at least one catalysis section 17 and then is supplied to the analyzer 20 in order to provide a reference measurement for calibration and / or verification of the analyzer 20. This reference measurement corresponds to a relatively high proportion of para hydrogen.

[0101] As illustrated, the installation may comprise a thermal insulator 14, for example a cold box encompassing cryogenic devices of the installation. The thermal insulation 14 may encompass at least one heat exchanger of the set of heat exchangers 4, 5, 6, 7, in particular the last exchangers 6, 7 downstream of the set of exchangers 4, 5, 6, 7, the upstream end of the sampling conduit 15 and the catalysis section 17.

[0102] As illustrated, the installation 300 may comprise a member 8 for collecting liquefied hydrogen, for example cryogenic storage and / or a pot separating the liquid and gas phases.

[0103] The installation may comprise a set of valve(s) configured to control the flow of hydrogen circulating in the sampling conduit 15. In particular, the set of valve(s) may be configured to expand the flow of hydrogen taken from the hydrogen circuit 3 upon introduction into the sampling conduit 15.

[0104] For example, the installation 300 may comprise a three-way valve at the junction of the sampling conduit 15 and the hydrogen circuit 3 to sample a determined quantity of pressurized hydrogen circulating in the hydrogen circuit 3 and to produce a flow of hydrogen in the sampling conduit 15.

[0105] The flow of hydrogen sampled is preferably at liquid / vapor equilibrium before being introduced into the apparatus 20.

[0106] The flow rate of hydrogen taken is of the order of ten g / h in comparison with the flow rate of hydrogen to be liquefied which is of the order of one ton to one hundred tons per hour. It therefore has no impact on the process or the productivity of the unit.

[0107] The upstream end of the sampling conduit 21 may be connected to the hydrogen circuit 3 containing hydrogen at a temperature higher than the determined temperature, preferably at ambient temperature. Thus, hydrogen at an ortho / para proportion corresponding to this temperature is transmitted to the analyzer 20 in order to provide a reference measurement for calibration and / or verification of the analyzer 20. This reference measurement corresponds to a relatively low proportion of para hydrogen.

[0108] The analyzer 20 may comprise one or more measurement inputs configured to receive respective hydrogen flows taken from different locations in the installation.

[0109] For example, the installation 200 may comprise a measuring conduit 23 having an upstream end connected to the hydrogen circuit 3 and a downstream end connected to (a measuring inlet of) the analyzer 20 in order to measure the relative proportions of ortho and para hydrogen of the hydrogen sampled. The upstream end of the measuring conduit 23 is preferably connected to the hydrogen circuit 3 downstream of the set of heat exchangers 4, 5, 6, 7.

[0110] The sampling conduit 15 may comprise at least one measuring member 18 and / or adjustment of the pressure and / or the temperature and / or the flow rate of the hydrogen. The member 18 is preferably located downstream of the catalysis section 17. For example, the member 18 can adjust the pressure in the case of a two-phase flow within the catalysis section 17. The member 18 can adjust the temperature at the outlet of the catalysis section 17 in the case of a supercritical flow within the catalysis section 17. The member 18 can adjust the flow rate of the hydrogen taken at liquid / vapor equilibrium before being fed into the analyzer 20. The member 18 can comprise at least one of: a valve, a temperature sensor, a pressure sensor, ...

[0111] The installation shown in [Fig.4] is another example of an installation for producing and / or storing liquid hydrogen. The embodiment of [Fig.4] differs from that of [Fig.3] essentially in that the upstream end of the sampling conduit 21 is connected to a hydrogen supply device 2 independent of the hydrogen circuit 3, for example a hydrogen bottle, at a temperature higher than the determined temperature, preferably at ambient temperature.

[0112] In this variant, the catalysis section 17 is located at the upstream end of the sampling conduit 15 and directly connected to the hydrogen circuit 3 downstream of the set of heat exchangers 4, 5, 6, 7.

[0113] Thus, the flow of cooled hydrogen in the circuit 3 splits into two with one of the two being a relatively low flow flowing by gravity into the catalysis section 17 (the remainder of the flow feeds a collection member 8 such as a storage 8). The flow of pressurized hydrogen taken from the sampling conduit 15 can be expanded to a pressure close to atmospheric pressure before feeding the analyzer 20.

[0114] The installation shown in [Fig. 5] is another example of an installation for producing and / or storing liquid hydrogen. The embodiment of [Fig. 5] differs from that of [Fig. 3] essentially in that the upstream end of the sampling conduit 15 is connected to a portion of the sampling located at the level of the member 8 for collecting the liquefied hydrogen.

[0115] [Fig. 6] represents an example of a liquid hydrogen production and / or storage installation 300 comprising a liquid hydrogen storage 8 (the upstream part of the storage 8 is omitted in the drawing in the case where the installation concerns a liquid hydrogen production installation). As illustrated, the liquefied hydrogen collection member 8 may be a cryogenic storage 24 and / or a separator pot 25 of a refrigerator. The upstream end of the sampling conduit 15 may be connected to a cryogenic storage 24 and / or a separator pot 25. The portion of the sampling conduit 15 which extends from the upstream end of the sampling conduit 15 to the catalysis section 17 is included in a thermal insulator, for example, a multilayer insulator MLI (not shown).

[0116] The upstream end of the sampling conduit 15 can be connected to the lower part 26 of this collection member 8 to sample liquid hydrogen and / or to the upper part 27 of this collection member 8 to sample gaseous hydrogen.

[0117] As illustrated in [Fig.7], the installation 300 may comprise a set of filling pipe(s) 28 having an upstream end(s) connected to the collection member 8. Alternatively or in combination, the upstream end of the filling pipe(s) 28 may be connected directly to the downstream end of the hydrogen circuit 3.

[0118] The filling pipe assembly 28 has a downstream end intended to be connected to a liquid hydrogen tank 30 to be filled with liquid hydrogen produced or stored by the installation. The tank 30 to be filled may be, for example, a mobile storage or a tank of a liquid hydrogen transport truck.

[0119] In this variant, the upstream end of the sampling conduit 15 is connected to the filling conduit(s) 28, that is to say that the sampling portion is located at the level of the filling conduit(s) 28. The portion of the sampling conduit 15 which extends from the upstream end of the sampling conduit 15 to the catalysis section 17 is included in a thermal insulator, for example, a multilayer insulator MLI (not shown).

[0120] As illustrated in [Fig.8], the installation may comprise a set of vaporization gas recovery pipe(s) 31 having a first end intended to be connected to a liquid hydrogen tank 30 to be filled and a second end connected to a receiving member of the installation, for example the collection member 8. The upstream end of the sampling pipe 15 is connected to the recovery pipe 31, that is to say that the sampling portion is located at the level of the vaporization gas recovery pipe(s) 31. The portion of the sampling pipe 15 which extends from the upstream end of the sampling pipe 15 to the catalysis section 17 is included in a thermal insulator, for example, a multilayer insulator MLI (not shown).

[0121] In this variant, the installation 300 may comprise a set of filling pipe(s) 28 having an upstream end connected to the collection member 8. Alternatively or in combination, the upstream end of the filling pipe(s) 28 may be connected directly to the downstream end of the hydrogen circuit 3. The set of filling pipe(s) 28 has a downstream end intended to be connected to the liquid hydrogen tank 30 to be filled with liquid hydrogen produced or stored by the installation. The tank 30 to be filled may be, for example, a mobile storage or a tank of a liquid hydrogen transport truck.

[0122] The installation 300 shown in [Fig.9] is an example of a liquid hydrogen production and / or storage installation. The embodiment of [Fig.9] is differs from that of [Fig.5] essentially in that the hydrogen circuit 3 comprises, downstream of the set of heat exchangers 4, 5, 6, 7, a separator pot 25 for the liquid and gas phases. Upstream of the separator pot 25, an expansion valve 33 makes it possible to pass from the supercritical state to a liquid / vapor equilibrium.

[0123] As illustrated, the inner part 26 of the separator pot 25 can be connected to a member 8 for collecting liquefied hydrogen, for example a cryogenic storage, downstream of the hydrogen circuit 3. The sampling conduit 15 is connected to the hydrogen circuit 3 downstream of the separator pot 25.

[0124] As illustrated in [Fig.10], the sampling conduit 15 can be connected to the upper part 27 of the separator pot 25 to sample the hydrogen gas.

[0125] The advantage of sampling from a liquid / vapor equilibrium is that the temperature is fixed. Heat inputs will increase the vaporized fraction, but at a fixed temperature. A pressure measurement, which is much easier and more precise under these conditions, is therefore sufficient to know the temperature of the hydrogen. The pressure measurement can be carried out by the member 18 located on the sampling conduit 15 (not shown in the figure).

[0126] The installation 300 shown in [Fig.l 1] is an example of an installation for producing and / or storing liquid hydrogen. The embodiment of [Fig.l 1] differs from that of [Fig.9] essentially in that the hydrogen circuit 3 comprises, downstream of the set of heat exchangers 4, 5, 6, 7, a hydrogen expansion turbine 29. When the turbine 29 is in operation, it subcools the liquid hydrogen at the outlet of the set of heat exchangers 4, 5, 6, 7, which makes it possible to produce liquid hydrogen without passing through a separator pot. When the latter is not operating, the liquid hydrogen at the outlet of the set of heat exchangers 4, 5, 6, 7 is expanded and passes through the separator pot 27. The liquid phase coming from the turbine 29 or the separator pot 25 is then sent to the member 8 for collecting liquefied hydrogen.The upstream end of the sampling conduit 15 can be connected to the hydrogen circuit 3 downstream of the turbine 29 and downstream of the separator pot 25. The sampling portion is located at the outlet of the turbine 29 and downstream of the separator pot 25.

[0127] The installation 300 shown in [Fig. 12] is an example of a liquid hydrogen production and / or storage installation. The embodiment of [Fig. 12] differs from that of [Fig. 11] essentially in that the hydrogen circuit 3 does not include a liquid and gas phase separator pot. The upstream end of the sampling conduit 15 can be connected to the hydrogen circuit 3 downstream of the hydrogen expansion turbine 29, i.e. at the outlet of the turbine 29. The sampling portion is located at the outlet of the turbine 29.

[0128] As illustrated in [Fig.13], the upstream end of the sampling conduit 15 can be connected to the hydrogen circuit 3 upstream of the hydrogen expansion turbine 29, i.e. at the inlet of the turbine 29. The sampling portion is located at the inlet of the turbine 29.

[0129] As illustrated in [Fig.14], the hydrogen circuit 3 may comprise, after the outlet of the expansion turbine 29, an additional passage 32 in at least one heat exchanger of the set of heat exchangers. When the turbine is in operation, it subcools the liquid hydrogen at the outlet of the set of heat exchangers 4, 5, 6, 7. In particular, the additional passage 32 passes the last exchanger 7 downstream of the set of exchangers 4, 5, 6, 7, which makes it possible to compensate for the partial subcooling in the event of a malfunction of the turbine 29. The turbine 29 may be bypassed by a valve 33, totally or partially.

[0130] In a variant, the upstream end of the sampling conduit 15 can be connected to the hydrogen circuit 3 downstream of the additional passage 32 in at least one heat exchanger. Thus, the sampling portion is located at the level of the hydrogen circuit 3 downstream of the additional passage in at least one heat exchanger.

[0131] In a variant illustrated in [Fig. 15], the upstream end of the sampling conduit 15 can be connected to the hydrogen circuit 3 upstream of the additional passage 32 in at least one heat exchanger. Thus, the sampling portion is located at the level of the hydrogen circuit 3 upstream of the additional passage in at least one heat exchanger.

[0132] In a variant illustrated in [Fig. 16], the upstream end of the sampling conduit 15 can be connected to the hydrogen circuit 3 upstream of the hydrogen expansion turbine 29 with the additional passage 32 downstream of the expansion turbine 29.

[0133] Various examples of sampling points for a relatively cold hydrogen flow have been described above to supply the calibration and / or verification device of the hydrogen composition measuring apparatus. These various examples make it possible to supply the apparatus with a relatively cold hydrogen flow at a determined temperature which can be known or measured if necessary. These samples provide a calibration and / or verification measurement distant from the warmer calibration and / or verification measurement (typically ambient temperature). These two distant reference points make it possible to calibrate the measuring apparatus with great precision without adding expensive and complex equipment and without significant consequences for the installation.

[0134] The invention also relates to a method for calibrating and / or verifying the measuring device or the measuring device of the installation described above. The method comprises sampling cooled hydrogen at a source of hydrogen at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K. The cooled hydrogen taken is brought into contact with at least one catalysis section 17 and converted from ortho hydrogen to para hydrogen up to the ortho / para equilibrium proportion corresponding to the determined temperature. The converted hydrogen is then supplied to the analyzer 20 as a reference measurement for calibration and / or verification of the analyzer 20.

[0135] The cooled hydrogen can be taken from the liquid hydrogen production and / or storage facility described above.

[0136] The method may comprise sampling hydrogen from a hydrogen source at a temperature above the determined temperature, preferably at room temperature. The hydrogen sampled at this temperature is then supplied to the analyzer 20 as a reference measurement for calibration and / or verification of the analyzer 20.

[0137] The method may comprise, before the sampling of cooled hydrogen, a step of connecting the downstream end of the sampling conduit 15 to the analyzer 20.

[0138] The method may also comprise, before the collection of cooled hydrogen, a step of connecting the upstream end of the conduit 15 to the hydrogen source at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K.

[0139] The method may comprise, after supplying the analyzer 20 with the converted hydrogen, a step of disconnecting the downstream end of the sampling conduit 15 from the analyzer 20. Alternatively, the method may comprise, after supplying the analyzer 20 with the converted hydrogen, a step of removing the converted hydrogen from the sampling conduit 15.

Claims

Claims

1. Device (100) for converting ortho hydrogen into para hydrogen comprising a sampling conduit (15) having an upstream end configured to be connected to a cold hydrogen source at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K, the sampling conduit (15) comprising at least one catalysis section (17) for the hydrogen sampled by the sampling conduit (15), the catalysis section (17) having a quantity of catalyst configured to ensure a conversion of ortho hydrogen into para hydrogen up to the ortho / para equilibrium composition corresponding to the determined temperature, the device comprising a thermal insulator (14) disposed on the sampling conduit (15) encompassing the upstream end and the catalysis section (17).

2. Device according to claim 1, characterized in that the sampling conduit (15) comprises a heating section (16) downstream of the catalysis section (17) which is located outside the thermal insulation (14).

3. Apparatus (200) for measuring the ortho / para composition of hydrogen comprising an analyzer (20) configured to measure the relative proportions of ortho and para hydrogen in the hydrogen, the analyzer (20) being of the type capable of being calibrated and / or verified by at least one reference measurement of hydrogen at a proportion of ortho and para hydrogen, the apparatus comprising a calibration and / or verification device comprising the device for converting ortho hydrogen into para hydrogen according to claim 1 or 2, said sampling conduit (15) comprising a downstream end configured to be connected to the analyzer (20), the hydrogen converted by the catalysis section (17) constituting a reference measurement for calibration and / or verification of the analyzer (20).

4. Apparatus according to claim 3, characterized in that the calibration and / or verification device comprises a sampling conduit (21) having an upstream end configured to be connected to a source of hydrogen at a temperature higher than the determined temperature, preferably at ambient temperature, and at a corresponding ortho / para proportion and a downstream end configured to be connected to the analyzer (20) to supply it with hydrogen in order to provide a second reference measurement for calibration and / or verification and / or for measuring the relative proportions of ortho and para hydrogen.

5. Apparatus according to claim 3 or 4, characterized in that the calibration and / or verification device comprises a source of hydrogen cooled to a determined temperature less than or equal to 80 K, in particular to a temperature less than or equal to 30 K.

6. Installation (300) for producing and / or storing liquid hydrogen comprising a hydrogen storage and / or circuit (3), the installation comprising a measuring apparatus (100) according to any one of claims 3 to 5, characterized in that the hydrogen storage and / or circuit (3) comprises at least one sampling portion which contains hydrogen at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K, and in that the upstream end of the sampling conduit (15) is connected to the sampling portion.

7. Installation (300) according to claim 6, comprising a hydrogen circuit, the hydrogen circuit (3) having an upstream end intended to be connected to a device (2) for supplying gaseous hydrogen and a downstream end intended to be connected to at least one member (8) for collecting liquefied hydrogen, the installation comprising a set of heat exchanger(s) (4, 5, 6, 7) in heat exchange with the hydrogen circuit (3) and a cooling system (9) in heat exchange with at least part of the set of heat exchanger(s), said cooling system (9) comprising a refrigerator with a refrigeration cycle of a cycle gas comprising helium and / or hydrogen, and said hydrogen circuit (3) comprising at least one catalysis section (13) configured to ensure a conversion of ortho hydrogen into para hydrogen.

8. Installation according to claim 7, characterized in that the upstream end of the sampling conduit (15) is connected to a portion of the sampling located at the level of the hydrogen circuit (3), downstream of one or more heat exchangers, in particular downstream of the set of heat exchanger(s) (4, 5, 6, 7).

9. Installation according to claim 7 or 8, characterized in that it comprises a member (8) for collecting liquefied hydrogen, for example a cryogenic storage (24) and / or a separator pot (25), the upstream end of the sampling conduit (15) being connected to a portion of the sampling located at the level of the liquefied hydrogen collection member (8).

10. Installation according to any one of claims 6 to 9, characterized in that it comprises a set of valve(s) configured to control the flow of hydrogen circulating in the sampling conduit (15).

11. Installation according to any one of claims 6 to 10, characterized in that the analyzer (20) comprises a plurality of measurement inputs and configured to receive respective hydrogen flows taken from different locations in the installation.

12. Installation according to any one of claims 6 to 11, characterized in that it comprises a measuring apparatus (100) according to claim 4, characterized in that the upstream end of the sampling conduit (21) is connected to the hydrogen circuit (3) or to another gaseous storage (2) of the installation containing hydrogen at a temperature higher than the determined temperature, preferably at ambient temperature and having an ortho / para proportion corresponding to this temperature.

13. Installation according to any one of claims 6 to 12, characterized in that it comprises a measuring conduit (23) having an upstream end connected to the hydrogen circuit (3) and a downstream end connected to the analyzer (20) in order to measure the relative proportions of ortho and para hydrogen of the hydrogen sampled.

14. Installation according to any one of claims 6 to 13, characterized in that the sampling conduit (15) comprises at least one member (18) for measuring and / or adjusting the pressure and / or the temperature and / or the flow rate of the hydrogen, said member (18) being located for example downstream of said at least one catalysis section (17).

15. Installation according to any one of claims 6 to 14, characterized in that the hydrogen circuit (3) comprises, downstream of the set of heat exchangers (4, 5, 6, 7), a hydrogen expansion turbine (29), the upstream end of the sampling conduit (15) being connected to the inlet or outlet of the expansion turbine, that is to say that the sampling portion is located at the inlet or outlet of the turbine.

16. Installation according to claim 15, characterized in that the hydrogen circuit (3) comprises, after the outlet of the expansion turbine (29), an additional passage (32) in at least one heat exchanger of the set of heat exchangers (4, 5, 6, 7), the upstream end of the sampling conduit (15) being connected to the hydrogen circuit (3) upstream or downstream of the additional passage in at least one heat exchanger, i.e. the sampling portion is located at the hydrogen circuit (3) upstream or downstream of the additional passage (32) in at least one heat exchanger.

17. Installation according to any one of claims 7 to 16, characterized in that it comprises a set of filling pipe(s) (28) having an upstream end connected to the collecting member (8) or connected directly to the downstream end of the hydrogen circuit (3) and a downstream end intended to be connected to a liquid hydrogen tank (30) to be filled with liquid hydrogen, and in that the upstream end of the sampling pipe (15) is connected to the filling pipe(s) (28), that is to say that the sampling portion is located at the level of the filling pipe(s) (28).

18. Installation according to claim 17, characterized in that it comprises a set of vaporization gas recovery pipe(s) (31) having a first end intended to be connected to a liquid hydrogen tank (30) to be filled and a second end connected to a receiving member of the installation, for example the collection member (8), and in that the upstream end of the sampling pipe (15) is connected to the recovery pipe (31), that is to say that the sampling portion is located at the level of the vaporization gas recovery pipe(s) (31).

19. Method for calibrating and / or verifying a measuring device according to any one of claims 3 to 5 or the measuring device of an installation according to any one of claims 6 to 18, comprising: - a sampling of cooled hydrogen at a hydrogen source at a determined temperature less than or equal to 80 K, in particular at a temperature less than or equal to 30 K, - a conversion of the cooled hydrogen sampled ortho into para hydrogen up to the ortho / para equilibrium proportion corresponding to the determined temperature, by bringing the cooled hydrogen sampled into contact with the at least one catalysis section (17), - supplying the analyzer (20) with the converted hydrogen as a reference measurement for calibration and / or verification of the analyzer.

20. Method according to claim 19 comprising: - sampling hydrogen from a hydrogen source at a temperature higher than the determined temperature, preferably at ambient temperature, - supplying the analyzer (20) with the hydrogen sampled at a temperature higher than the determined temperature as a reference measurement for calibration and / or verification of the analyzer.

21. Method according to claim 19 or 20, characterized in that the cooled hydrogen is taken from a liquid hydrogen production and / or storage installation according to any one of claims 6 to 18.

22. Method according to any one of claims 19 to 21, comprising: - before the sampling of cooled hydrogen, a step of connecting the downstream end of the sampling conduit (15) to the analyzer (20), - after the analyzer (20) is supplied with the converted hydrogen, a step of disconnecting the downstream end of the sampling conduit (15) from the analyzer (20).

Images