Cryogenic fluid production facility

Abstract

The invention relates to an installation (1) for the production of a cryogenic fluid, in particular liquefied hydrogen, comprising: a set of heat exchanger(s) (5, 6); a first cold box (4) having an enclosure (7) in which at least one cryogenic component is disposed, such as a portion of the heat exchanger(s) (5, 6), the enclosure (7) being intended to be maintained under vacuum; a pressurizable chamber (12), in particular a sealed chamber; a pumping system (11) fluidically connected to the enclosure (7), for establishing and / or maintaining a vacuum inside the enclosure (7), characterized in that the pumping system (11) is disposed in the pressurizable chamber (12). Abstract figure: Fig. 1

Description

Title of the invention: Installation for the production of a cryogenic fluid

[0001] The present invention relates to an installation for the production and / or storage of a cryogenic fluid.

[0002] Cryogenic fluid production installations equipped with at least one cold box designed to be evacuated are known. An example of such an installation is a hydrogen liquefier. The evacuation is achieved by at least one vacuum pump, which is generally located at a distance from the cold box, for example, at least 5 meters away. Indeed, near the cold box, there is a risk of explosion due to the possible presence of dihydrogen in the atmosphere.

[0003] Maintaining the vacuum pump at such a distance from the cold box implies limitations such as unnecessarily increasing the pump's power and / or increasing the pressure drop between the point of draw-off and the pump, thus making it more difficult to achieve the desired vacuum. Finally, such a pump arrangement relative to the rest of the installation requires a larger footprint and complicates the installation and maintenance of the piping connecting the pump to the cold box.

[0004] The present invention aims to effectively overcome these drawbacks by proposing an installation for the production and / or storage of a cryogenic fluid, in particular liquefied hydrogen, comprising: - a set of heat exchanger(s); - a first cold box comprising an enclosure in which is placed at least one cryogenic component such as part of the heat exchanger assembly(ies), the enclosure being intended to be maintained under vacuum - a pressurizable chamber, in particular a watertight one; - a pumping system fluidically connected to the enclosure, to put and / or maintain the inside of the enclosure under vacuum, characterized in that the pumping system is disposed in the pressurizable chamber.

[0005] The invention thus makes it possible to reduce the power of the pumping system and / or to reduce the pressure drop between the point of withdrawal, for example the containment, and the pumping system, while limiting the risk of explosion, particularly if the pumping system is not usable in an area where such risks exist. Such a reduction in the pressure drop between the point of withdrawal and the pumping system makes it possible to achieve the desired vacuum level.

[0006] The invention therefore makes it possible to use a pumping system that is not certified "UL NEMA", "NEC", "ATEX", "IEC Ex" or equivalent, even in an area with a risk of explosion, i.e., near the cold box. The invention thus makes it possible to bring the pumping system closer to the cold box, in particular the cold box responsible for cooling the cryogenic fluid to a temperature below -150 °C, specifically to a temperature less than or equal to -250 °C.

[0007] According to one embodiment, the pumping system presents a risk of ignition of dihydrogen, in particular by being devoid of “UL NEMA”, “NEC”, “ATEX”, “IEC Ex” or equivalent certification.

[0008] According to one embodiment, the pumping system is fluidly connected to the enclosure by a connection device, to put and / or maintain the inside of the enclosure under vacuum.

[0009] According to one embodiment, the pressurizable chamber includes a pressure measuring device, including in particular a Pirani gauge, configured to measure the vacuum in the enclosure and / or in the connection device and / or in the pumping system, by being for example fluidically connected to the connection device.

[0010] According to one embodiment, the pressure measuring device presents a risk of ignition of dihydrogen, in particular by not being certified “UL NEMA”, “NEC”, “ATEX”, “IEC Ex” or equivalent.

[0011] According to one embodiment, the pumping system includes a primary pumping unit, in particular intended to generate a primary vacuum.

[0012] According to one embodiment, the primary pumping unit includes a cooling circuit to allow the circulation of a cooling fluid such as water.

[0013] According to one embodiment, the pressurizable chamber includes a cooling inlet and a cooling outlet, for the circulation of the cooling fluid in the cooling circuit from a cooling fluid source located outside the pressurizable chamber.

[0014] According to one embodiment, the pumping system includes a secondary pumping unit, in particular intended to generate a secondary vacuum, the secondary pumping unit including in particular a diffusion pump, the primary pumping unit and the secondary pumping unit being in particular mounted in series.

[0015] According to one embodiment, the pressurizable chamber is configured to be swept, in particular continuously, with a sweeping gas such as nitrogen or air such as dry air.

[0016] According to one embodiment, the sweep gas includes air intended for instruments, for example so-called "instrument air".

[0017] According to one embodiment, the pressurizable chamber comprises a scavenging inlet and a scavenging outlet to allow the circulation of the scavenging gas through the pressurizable chamber.

[0018] Such an arrangement makes it possible to keep the pressurizable chamber under pressure while allowing the heat generated by the pumping system to be evacuated.

[0019] According to one embodiment, the sweep outlet is intended to be connected to a sweep line configured in particular to allow the sweep gas to be evacuated at a distance from the installation, in particular at a distance greater than 5 meters.

[0020] According to one embodiment, the pressurizable chamber includes a purge outlet, to fluidly connect an outlet of the pumping system to the outside of the pressurizable chamber, the purge outlet being in particular intended to be connected to a purge line to evacuate the purge gas exiting the pumping system away from the installation.

[0021] According to one embodiment, the pressurizable chamber includes a heater for heating the pumping system, the heater including in particular a semiconductor polymer core between two parallel copper conductors.

[0022] Such an arrangement makes it possible to heat the pumping system to ensure an optimized start-up, particularly when the installation is being commissioned.

[0023] According to one embodiment, the pressurizable chamber includes a maintenance door.

[0024] According to one embodiment, the installation comprises: - a circuit of gas to be cooled having an upstream end intended to be connected to a gas source and a downstream end intended to be connected to at least one receiving system, for example a cryogenic storage, the assembly of heat exchanger(s) being configured to be in heat exchange with the circuit of gas to be cooled; - a pre-cooling device in heat exchange with at least a first part of the heat exchanger assembly(ies) and configured to pre-cool the gas circuit to be cooled to a first determined temperature, - a cryogenic cooling device in heat exchange with at least a second part of the heat exchanger assembly(ies) and configured to cool the gas circuit to be cooled to a second determined temperature lower than the first temperature, the second part of the heat exchanger assembly(ies) being disposed in the enclosure.

[0025] According to one embodiment, at least part of the cryogenic cooling device is disposed in the enclosure.

[0026] According to one embodiment, the first part of the exchanger assembly(ies) is arranged in the first cold box or in a second cold box separate from the first cold box.

[0027] According to one embodiment, the second cold box is configured to pass the cryogenic fluid at a temperature between -20 °C and -150 °C.

[0028] According to one embodiment, the second cold box is pearl-sprayed and / or nitrogen-swept.

[0029] The invention may also relate to any alternative device comprising any combination of the above or below features.

[0030] The invention will be better understood upon reading the following description and examining the accompanying figures. These figures are given only to illustrate, but in no way limit, the invention.

[0031] [Fig-1] Fig. 1 is a schematic representation of an installation according to the invention; and

[0032] [Fig.2] [Fig.2] is a schematic representation of a detail of the installation according to [Fig.1].

[0033] With reference to Figures 1 and 2, a production and / or storage installation 1 for a cryogenic fluid, in particular liquefied hydrogen, is shown. Installation 1 in [Fig. 1] is, for example, a hydrogen liquefier.

[0034] Installation 1 comprises: - a set of heat exchanger(s) 5, 6; - a first cold box 4 comprising an enclosure 7 in which is equipped with at least one cryogenic organ such as part of the heat exchanger assembly(ies) 5, 6, the enclosure 7 being intended to be kept under vacuum; - a pressurizable chamber 12, in particular watertight; - a pumping system 11 fluidically connected to the enclosure 7, to put and / or maintain the inside of the enclosure 7 under vacuum.

[0035] As seen in [Fig.1], the pumping system 11 is arranged in the pressurizable chamber 12.

[0036] The pumping system 11 presents a risk of hydrogen ignition. For example, it lacks "UL NEMA", "NEC", "ATEX", or "IEC Ex" type certification, being incompatible with these certifications. Therefore, the pumping system 11 cannot be placed near the cold box, which is located in an area where there is a risk of hydrogen explosion.

[0037] The pumping system 11 is fluidly connected to the enclosure 7 by a connection device 10, to put and / or maintain the inside of the enclosure 7 under vacuum.

[0038] The pressurizable chamber 12 includes a pressure measuring device 15, including in particular a Pirani gauge, configured to measure the vacuum in the enclosure 7 and / or in the connection device 10 and / or in the pumping system 11, by being for example fluidically connected to the connection device 10.

[0039] The pressure measuring device 15 presents a risk of ignition of the di- hydrogen. For example, it lacks certifications such as "UL NEMA", "NEC", "ATEX", or "IEC Ex", being incompatible with these certifications.

[0040] The pumping system 11 includes a primary pumping unit 13, in particular intended to generate a primary vacuum.

[0041] The primary pumping unit 13 includes a cooling circuit 16 for circulating a cooling fluid such as water. The pressurizable chamber 12 includes a cooling inlet and a cooling outlet for circulating the cooling fluid in the cooling circuit 16 from a cooling fluid source located outside the pressurizable chamber 12.

[0042] The pumping system 11 includes a secondary pumping unit 14, in particular intended to generate a secondary vacuum, the secondary pumping unit 14 including in particular a diffusion pump, the primary pumping unit 13 and the secondary pumping unit 14 being in particular mounted in series.

[0043] The pressurizable chamber 12 is configured to be purged, in particular continuously, with a purging gas such as nitrogen or air such as dry air, such as so-called "instrument air". More specifically, the enclosure 7 of the pressurizable chamber 12 is configured to be purged, in particular continuously, with a purging gas such as nitrogen or air such as dry air, such as so-called "instrument air".

[0044] The pressurizable chamber 12 has a scavenging inlet 19 and a scavenging outlet 17 to allow the circulation of the scavenging gas through the pressurizable chamber 12.

[0045] The sweep outlet 17 is intended to be connected to a sweep line configured in particular to allow the sweep gas to be evacuated at a distance from the installation, in particular at a distance greater than 5 meters.

[0046] The pressurizable chamber 12 includes a purge outlet 18, for fluidly connecting an outlet of the pumping system 11 to the outside of the pressurizable chamber 12, the purge outlet 18 being in particular intended to be connected to a purge line to evacuate the purge gas exiting the pumping system 11 away from the installation 1.

[0047] The pressurizable chamber 12 includes at least one heater 20 for heating the pumping system 11, the heater 20 including in particular a semiconductor polymer core between two parallel copper conductors.

[0048] Installation 1 comprises: - a gas circuit to be cooled 2 having an upstream end 21 intended to be connected to a gas source and a downstream end 22 intended to be connected to at least one receiving system, for example a cryogenic storage 40, the heat exchanger assembly(ies) 5, 6 being configured to be in heat exchange with the gas circuit to be cooled 2; - a pre-cooling device 8 in heat exchange with at least a first part 5 of the heat exchanger assembly(ies) 5, 6 and configured to pre-cool the gas circuit to be cooled 2 to a first determined temperature, - a cryogenic cooling device 9 in heat exchange with at least a second part 6 of the heat exchanger assembly(ies) 5, 6 and configured to cool the gas circuit to be cooled 2 to a second determined temperature lower than the first temperature, the second part 6 of the heat exchanger assembly(ies) 5, 6 being disposed in the enclosure 7.

[0049] At least a part of the cryogenic cooling device 9 is disposed in the enclosure 7.

[0050] The pre-cooling device 8 includes a refrigerator with a pre-cooling fluid refrigeration cycle in a pre-cooling circuit, the pre-cooling circuit including a pre-cooling fluid compression element 28.

[0051] The pre-cooling circuit includes a pre-cooling fluid expansion device 38.

[0052] The cryogenic cooling device 9 comprises a cycle refrigerator for refrigerating a cycle gas in a cycle circuit, the cycle circuit comprising a cycle gas compression element 29.

[0053] The cycle circuit includes a cooling element for the compressed cycle gas, an expansion element 39 for the compressed and cooled cycle gas and a heating element for the expanded cycle gas.

[0054] The second temperature determined is between 48 K and 18 K and the first temperature determined is between 100 K and 70 K.

[0055] The first part 5 of the exchanger assembly(ies) is disposed in the first cold box 4 or in a second cold box 3.

[0056] The second cold box 3 is perlited and / or nitrogen-swept, in particular without being intended to be vacuum-sealed.

[0057] The circuit 2 of gas to be cooled is provided with an expansion member 23 downstream of the downstream end 22, being in particular configured to regulate the pressure in the cryogenic storage 40, the expansion member 23 comprising for example an expansion valve, in particular a Joule-Thomson expansion valve.

[0058] The expansion member 23 and the expansion member 39 of the cycle gas are arranged in the second cold box 4.

[0059] Considering that the atmospheric pressure around the first and / or second cold box is approximately 1,000 bar, then the nitrogen pressure in the second cold box 3 is about 1.020 bar while the pressure inside the enclosure of the first cold box 4 is about equal to 5.10-6 mbar.

Claims

Demands

1. Installation (1) for the production and / or storage of a cryogenic fluid, in particular liquefied hydrogen, comprising: - a set of heat exchanger(s) (5, 6); - a first cold box (4) having an enclosure (7) in which is disposed at least one cryogenic component such as a part of the set of heat exchanger(s) (5, 6), the enclosure (7) being intended to be maintained under vacuum; - a pressurizable chamber (12), in particular sealed; - a pumping system (11) fluidically connected to the enclosure (7), for putting and / or maintaining the interior of the enclosure (7) under vacuum, characterized in that the pumping system (11) is disposed in the pressurizable chamber (12).

2. Installation (1) according to the preceding claim, the pumping system (11) being fluidly connected to the enclosure (7) by a connecting device (10), to put and / or maintain the inside of the enclosure (7) under vacuum.

3. Installation (1) according to the preceding claim, the pressurizable chamber (12) comprising a pressure measuring device (15), including in particular a Pirani gauge, configured to measure the vacuum in the enclosure (7) and / or in the connection device (10) and / or in the pumping system (11), by being for example fluidly connected to the connection device (10).

4. Installation (1) according to any one of the preceding claims, the pumping system (11) comprising a primary pumping unit (13), in particular intended to generate a primary vacuum.

5. Installation (1) according to the preceding claim, the pumping system (11) comprising a secondary pumping unit (14) in particular intended to generate a secondary vacuum, the secondary pumping unit (14) comprising in particular a diffusion pump, the primary pumping unit (13) and the secondary pumping unit (14) being in particular mounted in series.

6. Installation (1) according to any one of the preceding claims, the pressurizable chamber (12) being configured to be purged, in particular continuously, with a purging gas such as nitrogen or air such as dry air.

7. Installation (1) according to any one of the preceding claims, the pressurizable chamber (12) having a purge outlet (18), for fluidly connecting an outlet of the pumping system (11) to the outside of the pressurizable chamber (12), the purge outlet (18) being in particular intended to be connected to a purge line to evacuate the purge gas exiting the pumping system (11) away from the installation (1).

8. Installation (1) according to any one of the preceding claims, the pressurizable chamber (12) comprising a heater (20) for heating the pumping system (11), the heater comprising in particular a semiconductor polymer core between two parallel copper conductors.

9. Installation (1) according to any one of the preceding claims, comprising: - a circuit for the gas to be cooled (2) having an upstream end (21) intended to be connected to a gas source and a downstream end (22) intended to be connected to at least one receiving system, for example a cryogenic storage (40), the assembly of heat exchanger(s) (5, 6) being configured to be in heat exchange with the circuit for the gas to be cooled (2);- a pre-cooling device (8) in heat exchange with at least a first part (5) of the heat exchanger assembly (5, 6) and configured to pre-cool the gas circuit to be cooled (2) to a first determined temperature, - a cryogenic cooling device (9) in heat exchange with at least a second part (6) of the heat exchanger assembly (5, 6) and configured to cool the gas circuit to be cooled (2) to a second determined temperature lower than the first temperature, the second part (6) of the heat exchanger assembly (5, 6) being disposed in the enclosure.;

10. Installation (1) according to the preceding claim, the first part (5) of the exchanger assembly(ies) being disposed in the first cold box (4) or in a second cold box (3).

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