Cryogenic fluid production facility

Abstract

The present invention relates to an apparatus (1) for producing cryogenic fluids, particularly liquid hydrogen, wherein the apparatus comprises: - a set of one or more heat exchangers (5, 6); - a first cold box (4) comprising an enclosure (7) having at least one cryogenic unit such as part of the set of one or more heat exchangers (5, 6), wherein the enclosure (7) is intended to be maintained in a vacuum state; - a pressurizable, particularly sealed container (12); - a pumping system (11) fluidly connected to the enclosure (7) to keep / keep the interior of the enclosure (7) in a vacuum state, wherein the pumping system (11) is disposed within the pressurizable container (12).

Description

Technology Field

[0001] The present invention relates to an apparatus for producing and / or storing cryogenic fluids. Background Technology

[0002] Cryogenic-fluid production facilities equipped with at least one cold box intended to be maintained under vacuum are known. An example of such a facility is a hydrogen liquefier. The vacuum is typically applied by at least one vacuum pump located away from the cold box, for example, at least 5 meters away. This is because there is a risk of explosion associated with the possibility of hydrogen being present in the atmosphere if it is close to the cold box.

[0003] Maintaining the vacuum pump at such a distance from the cold box implies that constraints must be enforced, such as unnecessarily increasing the pump's output or increasing the pressure drop between the discharge point and the pump, which creates additional difficulty in achieving the required vacuum. Finally, this placement of the pump relative to the rest of the installation requires a larger footprint and complicates the installation and support of the piping connecting the pump to the cold box.

[0004] The present invention aims to effectively solve these disadvantages by providing a facility for producing and / or storing cryogenic fluids, in particular liquid hydrogen, wherein the facility comprises

[0005] - A set of one or more heat exchangers;

[0006] - A first cold box having an enclosure comprising at least one cryogenic unit, such as part of a set of one or more heat exchangers, wherein the enclosure is intended to be maintained in a vacuum state;

[0007] - Pressurizable, especially a sealed chamber;

[0008] - Includes a pumping system fluidly connected to the enclosure to keep / maintain a vacuum inside the enclosure, and is characterized in that the pumping system is positioned within a pressurizable chamber.

[0009] Accordingly, the present invention makes it possible to reduce the output of the pumping system and / or reduce the pressure drop at the discharge point, e.g., between the enclosure and the pumping system, while limiting the risk of explosion, particularly in cases where the pumping system cannot be used in an area where such risks exist. This reduction in the pressure drop between the discharge point and the pumping system assists in obtaining the required vacuum level.

[0010] Accordingly, the present invention enables a pumping system that does not have certifications of the type "UL NEMA", "NEC", "ATEX", "IEC Ex", etc., to be used in an area with a risk of explosion, namely a cold box. Accordingly, the present invention enables the pumping system to be placed closer to a cold box, in particular a cold box that serves to keep cryogenic fluids at a temperature below -150°C, particularly below -250°C.

[0011] According to one embodiment, the pumping system exhibits a hydrogen ignition risk and does not have certifications of the type, such as "UL NEMA", "NEC", "ATEX", "IEC Ex", etc.

[0012] In one embodiment, the pumping system is fluidly connected to the enclosure by a connecting device to keep / keep the interior of the enclosure under vacuum.

[0013] According to one embodiment, the pressurizable chamber is intended to be maintained in a pressure state, and in particular, is intended to be maintained at a pressure higher than atmospheric pressure.

[0014] According to one embodiment, the enclosure is fluidly isolated from a pressurizable chamber.

[0015] According to one embodiment, the pressurizable chamber is separated from the enclosure.

[0016] According to one embodiment, a pressurizable chamber is positioned outside the enclosure.

[0017] According to one embodiment, the pressurizable chamber is separated from the pumping system.

[0018] According to one embodiment, the pumping system is positioned outside the enclosure.

[0019] According to one embodiment, a pressurizable chamber has a pressure measuring device, the pressure measuring device including, in particular, a Pirani gauge and configured to measure a vacuum within an enclosure and / or a connecting device and / or a pumping system by being fluidly connected to, for example, a connecting device.

[0020] According to one embodiment, the pressure measuring device exhibits a hydrogen ignition risk and, in particular, does not have certifications of the type such as "UL NEMA", "NEC", "ATEX", "IEC Ex", etc.

[0021] According to one embodiment, the pumping system has a primary pumping unit, in particular, for generating a primary vacuum.

[0022] According to one embodiment, the primary pumping unit has a cooling circuit for the flow of a coolant such as water.

[0023] According to one embodiment, the pressurizable chamber has a cooling inlet and a cooling outlet for the flow of coolant in a cooling circuit from a coolant source located outside the pressurizable chamber.

[0024] According to one embodiment, the pumping system has a secondary pumping unit for generating a secondary vacuum, the secondary pumping unit has a diffusion pump, and the primary pumping unit and the secondary pumping unit are connected in series.

[0025] According to one embodiment, the pressurizable chamber is configured to be flushed particularly continuously with a flushing gas such as nitrogen or air such as dry air.

[0026] According to one embodiment, the flushing gas includes air intended for instrumentation, for example, air referred to as "instrument air."

[0027] According to one embodiment, the flushing gas has an H2 impurity content of less than 0.1 ppm, particularly equal to 0 ppm.

[0028] According to one embodiment, the pressurizable chamber has a flushing inlet and a flushing outlet for the flow of flushing gas through the pressurizable chamber.

[0029] This arrangement allows the pressurizable chamber to be maintained under pressure while continuously allowing the heat generated by the pumping system to be discharged.

[0030] According to one embodiment, the flushing outlet is intended to be connected to a flushing pipe configured to allow flushing gas to be discharged, particularly at a distance greater than 5 meters, away from the facility.

[0031] According to one embodiment, the pressurizable chamber has a purge outlet for fluidically connecting the outlet of a pumping system to the outside of the pressurizable chamber, and the purge outlet is intended to be connected to a purge pipe, in particular, for discharging purge gas coming from the pumping system away from the facility.

[0032] According to one embodiment, the pressurizable chamber has a heater for heating a pumping system, and the heater has a semiconductor polymer core between two parallel copper conductors.

[0033] This arrangement allows the pumping system to be heated, particularly to ensure an optimized start when the equipment is first used.

[0034] According to one embodiment, the pressurizable chamber has a maintenance door.

[0035] According to one embodiment, the facility is,

[0036] - A circuit for a 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, e.g., a cryogenic storage facility, wherein a set of one or more heat exchangers is configured to exchange heat with the circuit for the gas to be cooled;

[0037] - A pre-cooling device configured to exchange heat with at least a first part of a set of one or more heat exchangers and to pre-cool a circuit for gas to be cooled to a given first temperature;

[0038] - A cryogenic cooling device configured to exchange heat with at least a second part of a set of one or more heat exchangers and to cool a circuit for a gas to be cooled to a given second temperature lower than a first temperature, wherein the second part of the set of one or more heat exchangers is disposed within an enclosure.

[0039] According to one embodiment, at least a portion of the cryogenic cooling device is placed within an enclosure.

[0040] According to one embodiment, a first portion of a set of one or more heat exchangers is placed in a first cold box or in a second cold box separated from the first cold box.

[0041] In one embodiment, the second cold box is configured to keep the cryogenic fluid at a temperature of -20°C to -150°C.

[0042] According to one embodiment, the second cold box is filled with perlite and / or flushed with nitrogen.

[0043] The present invention may also relate to any alternative device comprising any combination of the features described above or the features described below.

[0044] The present invention may be better understood by reviewing the following description and the accompanying drawings. Brief explanation of the drawing

[0045] These drawings are provided merely as examples and do not limit the invention in any way. FIG. 1 is a schematic diagram of an apparatus according to the present invention. Figure 2 is a schematic diagram of the detailed parts of the equipment according to Figure 1. Specific details for implementing the invention

[0046] Referring to FIGS. 1 and 2, an apparatus (1) for producing and / or storing cryogenic fluids, particularly liquefied hydrogen, is illustrated. The apparatus (1) of FIG. 1 is, for example, a hydrogen liquefier.

[0047] The equipment (1) is,

[0048] - A set of one or more heat exchangers (5, 6);

[0049] - A first cold box (4) having an enclosure (7) comprising at least one cryogenic unit such as part of a set of one or more heat exchangers (5, 6), wherein the enclosure (7) is intended to be maintained in a vacuum state;

[0050] - Pressurizable, especially a sealed chamber (12);

[0051] - Includes a pumping system (11) fluidly connected to the enclosure (7) to keep / keep the interior of the enclosure (7) in a vacuum state.

[0052] As can be seen in FIG. 1, the pumping system (11) is placed inside a pressurizable chamber (12).

[0053] The pumping system (11) presents a hydrogen ignition risk. The pumping system is not compatible with, for example, "UL NEMA", "NEC", "ATEX", or "IEC Ex" type certifications and therefore does not have such certifications. Consequently, the pumping system (11) cannot be placed near a cold box located in an area where there is an explosion risk associated with hydrogen.

[0054] The pumping system (11) is fluidly connected to the enclosure (7) by a connecting device (10) to keep / keep or maintain the interior of the enclosure (7) in a vacuum state.

[0055] The pressurizable chamber (12) has a pressure measuring device (15), the pressure measuring device including, in particular, a Pirani gauge and configured to measure the vacuum within the enclosure (7) and / or the connecting device (10) and / or the pumping system (11) by being fluidly connected to, for example, the connecting device (10).

[0056] The pressure measuring device (15) indicates a hydrogen ignition risk. For example, the pressure measuring device is not compatible with certifications of the "UL NEMA", "NEC", "ATEX", or "IEC Ex" type and does not have such certifications.

[0057] The pumping system (11) has a primary pumping unit (13) for generating a primary vacuum in particular.

[0058] The primary pumping unit (13) has a cooling circuit (16) for the flow of a coolant such as water. The pressurizable chamber (12) has a cooling inlet and a cooling outlet for the flow of a coolant in the cooling circuit (16) from a coolant source located outside the pressurizable chamber (12).

[0059] The pumping system (11) has a secondary pumping unit (14) for generating a secondary vacuum, the secondary pumping unit (14) has a diffusion pump, and the primary pumping unit (13) and the secondary pumping unit (14) are connected in series.

[0060] The pressurizable chamber (12) is configured to be flushed continuously, particularly with a flushing gas such as nitrogen, or air such as dry air, for example, air referred to as "instrumentation air."

[0061] The pressurizable chamber (12) has a flushing inlet (19) and a flushing outlet (17) for the flow of flushing gas through the pressurizable chamber (12).

[0062] The flushing outlet (17) is intended to be connected to a flushing pipe configured to allow flushing gas to be discharged, particularly far from the facility, especially at a distance greater than 5 meters.

[0063] The pressurizable chamber (12) has a purge outlet (18) for fluidically connecting the outlet of the pumping system (11) to the outside of the pressurizable chamber (12), and the purge outlet (18) is intended to be connected to a purge pipe for discharging purge gas coming from the pumping system (11) away from the facility (1).

[0064] The pressurizable chamber (12) has at least one heater (20) for heating the pumping system (11), and the heater (20) has a semiconductor polymer core between two parallel copper conductors.

[0065] The equipment (1) is,

[0066] - A circuit (2) for gas to be cooled 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, such as a cryogenic storage facility (40), wherein a set of one or more heat exchangers (5, 6) is configured to exchange heat with the circuit (2) for gas to be cooled;

[0067] - A pre-cooling device (8) configured to exchange heat with at least a first part (5) of a set of one or more heat exchangers (5, 6) and to pre-cool a circuit (2) for gas to be cooled to a given first temperature;

[0068] - A cryogenic cooling device (9) configured to exchange heat with at least a second part (6) of a set of one or more heat exchangers (5, 6) and to cool a circuit (2) for gas to be cooled to a given second temperature lower than a first temperature, wherein the second part (6) of the set of one or more heat exchangers (5, 6) includes a cryogenic cooling device disposed within an enclosure (7).

[0069] At least a portion of the cryogenic cooling device (9) is placed inside the enclosure (7).

[0070] The pre-cooling device (8) includes a cooler having a cooling cycle for cooling a pre-cooling agent within a pre-cooling circuit, and the pre-cooling circuit includes a unit (28) for compressing the pre-cooling agent.

[0071] The pre-cooling circuit has an expansion unit (38) for expanding the pre-coolant.

[0072] The cryogenic cooling device (9) includes a cooler having a cooling cycle for cooling the cycle gas within the cycle circuit, and the cycle circuit includes a unit (29) for compressing the cycle gas.

[0073] The cycle circuit includes a unit for cooling the compressed cycle gas, an expansion unit (39) for expanding the compressed and cooled cycle gas, and a unit for heating the expanded cycle gas.

[0074] The given second temperature is included in the range of 48 K to 18 K, and the given first temperature is included in the range of 100 K to 70 K.

[0075] A first part (5) of a set of one or more heat exchangers is placed in a first cold box (4) or in a second cold box (3).

[0076] The second cold box (3) is filled with perlite and / or flushed with nitrogen, and is not intended to be placed under vacuum in particular.

[0077] The circuit (2) for the gas to be cooled is equipped with an expansion unit (23) downstream of the downstream section (22), and the expansion unit is configured to control the pressure, in particular, within the cryogenic storage facility (40), and the expansion unit (23) has, for example, an expansion valve, in particular a Joule-Thomson expansion valve.

[0078] The expansion unit (39) and expansion unit (23) for expanding the cycle gas are placed in the second cold box (4).

[0079] Considering that the atmospheric pressure widely distributed around the first and / or second cold box is approximately 1,000 bar, the nitrogen pressure widely distributed within the second cold box (3) is approximately 1,020 bar, whereas the pressure within the enclosure of the first cold box (4) is approximately 5×10 -6 It is the same as mbar.

Claims

Claim 1 A facility (1) for producing and / or storing cryogenic fluids, particularly liquid hydrogen, comprising: - a set of one or more heat exchangers (5, 6); - a first cold box (4) having an enclosure (7) comprising at least one cryogenic unit such as part of the set of one or more heat exchangers (5, 6), wherein the enclosure (7) is intended to be maintained in a vacuum state; - a pressurizable, particularly sealed chamber (12); - a pumping system (11) fluidly connected to the enclosure (7) to keep / keep or maintain the interior of the enclosure (7) in a vacuum state, wherein the pumping system (11) is disposed within the pressurizable chamber (12). Claim 2 In claim 1, the pumping system (11) is a facility (1) fluidly connected to the enclosure (7) by a connecting device (10) to keep / keep the interior of the enclosure (7) under vacuum. Claim 3 In claim 1 or 2, the pressurizable chamber (12) has a pressure measuring device (15), the pressure measuring device including, in particular, a Pirani gauge and configured to measure the vacuum within the enclosure (7) and / or the connecting device (10) and / or the pumping system (11) by being fluidly connected, for example, to the connecting device (10). Claim 4 In any one of claims 1 to 3, the pumping system (11) is a facility (1) having a primary pumping unit (13) for generating a primary vacuum in particular. Claim 5 In any one of claims 1 to 4, the pumping system (11) particularly has a secondary pumping unit (14) for generating a secondary vacuum, the secondary pumping unit (14) particularly has a diffusion pump, and the primary pumping unit (13) and the secondary pumping unit (14) are particularly connected in series, the facility (1). Claim 6 In any one of claims 1 to 5, the pressurizable chamber (12) is configured to be flushed particularly continuously with a flushing gas such as nitrogen or air such as dry air, the apparatus (1). Claim 7 In any one of claims 1 to 6, the pressurizable chamber (12) has a purge outlet (18) for fluidically connecting the outlet of the pumping system (11) to the outside of the pressurizable chamber (12), and the purge outlet (18) is intended to be connected to a purge pipe for discharging purge gas coming from the pumping system (11) away from the facility (1). Claim 8 In any one of claims 1 to 7, the pressurizable chamber (12) has a heater (20) for heating the pumping system (11), and the heater has a semiconductor polymer core between two parallel copper conductors, in particular, the facility (1). Claim 9 In any one of claims 1 to 8, - a gas circuit (2) for gas to be cooled 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, such as a cryogenic storage facility (40), wherein a set of one or more heat exchangers (5, 6) is configured to exchange heat with the gas circuit (2) for gas to be cooled; - a pre-cooling device (8) configured to exchange heat with at least a first part (5) of the set of one or more heat exchangers (5, 6) and to pre-cool the gas circuit (2) for gas to be cooled to a given first temperature; - A cryogenic cooling device (9) configured to exchange heat with at least a second part (6) of a set of one or more heat exchangers (5, 6) and to cool a circuit (2) for gas to be cooled to a given second temperature lower than the first temperature, wherein the second part (6) of the set of one or more heat exchangers (5, 6) is disposed within the enclosure, the facility (1) comprising the cryogenic cooling device (9). Claim 10 In any one of claims 1 to 9, the first part (5) of the set of one or more heat exchangers is placed in the first cold box (4) or in the second cold box (3), the facility (1).

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