Refrigeration cycle refrigerator and liquefaction device and process

Abstract

The invention relates to a refrigerator with a refrigeration cycle of a cycle gas comprising predominantly hydrogen and / or helium, having a cycle circuit (12) with a cycle gas compression mechanism (21, 22), a cycle gas cooling device (23, 5), a cycle gas expansion mechanism (24, 25), and a device (5) for heating the expanded cycle gas. The compression mechanism comprises at least one volumetric and reciprocating compression stage (21) and at least two centrifugal compression stages (22) arranged in series. The expansion mechanism comprises at least two centripetal expansion turbines (24), at least one of the turbines (24) being mechanically coupled (122) to a centrifugal compression stage (22), wherein the at least one volumetric reciprocating compression stage (21) is arranged in series and upstream of the at least two compression stages (22). Centrifugal. Abbreviated figure: Fig. 1

Description

Title of the invention: Refrigeration cycle refrigerator and liquefaction device and method

[0001] The invention relates to a refrigeration cycle refrigerator and a liquefaction device and method.

[0002] The invention relates more particularly to a refrigerator with a refrigeration cycle of a cycle gas comprising mainly hydrogen and / or helium, the refrigerator having a cycle circuit comprising: a mechanism for compressing the cycle gas, at least one member for cooling the cycle gas, a mechanism for expanding the cycle gas and at least one member for reheating the expanded cycle gas, the compression mechanism comprises at least one compression stage of the volumetric and alternating type and at least two centrifugal compression stages arranged in series, the expansion mechanism comprising at least two expansion turbines of the centripetal type, at least one of the turbines being mechanically coupled to a centrifugal compression stage so as to provide the compression stage with mechanical work produced during expansion.

[0003] It is known to recover the expansion work of turbines to centrifugal compressors. Documents US2022390169A and WO2022033714A1 describe refrigerator solutions.

[0004] The known solutions are however not very satisfactory, for example for large hydrogen liquefiers (low efficiency, low operating pressure, low compression ratio of centrifugal compression, etc.).

[0005] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0006] To this end, the refrigerator according to the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that the at least one alternating volumetric type compression stage is arranged in series and upstream of the at least two centrifugal compression stages.

[0007] Furthermore, embodiments of the invention may include one or more of the following features: - the compression mechanism comprises at least three centrifugal compression stages arranged in series, - the expansion mechanism comprises at least two turbines mechanically coupled respectively to respective centrifugal compression stages, - the compression mechanism comprises at least two volumetric and reciprocating compression stages arranged in series, the expansion mechanism comprises at least one Joule Thomson type expansion valve arranged in series downstream of at least one of the two expansion turbines, the at least one volumetric and reciprocating type compression stage comprises a piston compressor, the piston compressor comprises a movable piston in a compression chamber of the cycle gas, an actuator of the piston and a system for admitting the cycle gas to be compressed into the compression chamber, a system for discharging the compressed cycle gas out of the compression chamber, and a control member of the admission system and / or the discharge system for controlling the mass flow rate and / or the compression ratio of the volumetric and reciprocating type compression stage, the refrigerator comprises a system for regulating at least one of the expansion turbines and comprising a throttle valve at the inlet of the expansion turbine and / or a system for bypassing the flow of fluid supplying the turbine, the control member controls the opening or closing of an extension of the volume of the compression chamber, said extension being able to be activated to modify the mass flow rate that the piston compressor must compress, the system for regulating the at least one expansion turbine is configured to maintain a determined expansion rate at the terminals of the turbine, the refrigerator comprises a downstream compression regulation system configured to regulate the at least two centrifugal compression stages arranged in series, said downstream compression regulation system comprising at least one of: a bypass system for the fluid flow supplying all or part of the centrifugal compression stages, a frequency variator associated with at least one of the centrifugal compression stages, an inlet flow regulator ("IGV") for the gas flow supplying at least one of the centrifugal compression stages, the downstream compression control system is configured to control the cycle gas flow rate in the centrifugal compression stages and for example to decrease the cycle gas flow rate in the centrifugal compression stages in response to a decrease in the cycle gas flow rate admitted to the turbines, the cycle circuit comprises a pressure pulsation damping volume arranged between the volumetric and reciprocating type compression stages and the centrifugal compression stages, for example a storage pressurized buffer, the damping volume being sized to reduce by a factor of between ten and one hundred the pressure amplitudes of the cycle gas between the outlet of the volumetric and reciprocating type compression stage(s) and the inlet of the centrifugal compression stages, - the cycle circuit is without a cooling member for the cycle gas at the outlet of at least one of the centrifugal compression stages other than the last centrifugal compression stage.

[0008] The invention also relates to a device for liquefying a feed fluid such as hydrogen and / or helium comprising a feed fluid circuit having an upstream end intended to be connected to a source of feed gas and a downstream end intended to be connected to a member for collecting the liquefied feed gas, the device comprising a set of heat exchanger(s) in heat exchange with the feed fluid circuit, the device comprising at least one refrigerator in heat exchange with at least part of the set of heat exchanger(s), the refrigerator conforming to any one of the characteristics above or below.

[0009] According to other possible particularities:

[0010] - in response to a signal representative of the reduction in the thermal load of the circuit of supply fluid, the control member of the intake system and the discharge system is configured to reduce the pressure and / or the mass flow rate at the outlet of the volumetric and alternative type compression stage by modifying the mass flow rate and / or the compression ratio of the volumetric and alternative type compression stage, the signal representative of the reduction in the thermal load of the supply fluid circuit being for example provided by a member for determining the flow rate and / or the characteristics of the gas flow supplying the device and / or a measurement of a determined change in temperature of a cold end of the cycle circuit of the refrigerator at equal operation and / or a measurement of a determined change in temperature on the supply fluid circuit at equal operation, for example downstream of the set of heat exchangers and upstream of an expansion valve,

[0011] The invention also relates to a method for liquefying a feed fluid, for example hydrogen, using a liquefaction device conforming to any one of the characteristics above or below, comprising, a compression of the cycle gas first of the volumetric and alternating type and then a compression of the cycle gas of the centrifugal type, a centripetal expansion of the centrifugally compressed cycle gas and a step of recovering part of the centripetal expansion work for the centrifugal compression.

[0012] According to a possible feature, the method comprises a step of regulating the mass flow rate of compressed cycle gas in volumetric type compression and alternative depending on the thermal load of the feed gas flow and a stage of regulating the cycle gas flow rate in centripetal expansion and in centrifugal compression depending on the mass flow rate of compressed cycle gas in volumetric and alternative type compression.

[0013] 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.

[0014] Other features and advantages will appear on reading the description below, given with reference to the figures in which: Brief description of the figures

[0015] The invention will be better understood on reading the following description given solely by way of example and with reference to the appended drawings in which:

[0016] [Fig. 1] is a schematic and partial view illustrating an example of structure and operation of a first example of liquefaction device with refrigerator according to the invention,

[0017] [Fig.2] is a schematic and partial view illustrating a second example of structure and operation of a refrigerator according to the invention,

[0018] [Fig.3] is a schematic and partial view of a detail of a variant of the compression system that can be used in a refrigerator according to the invention. Detailed description

[0019] In all the figures, the same references refer to the same elements.

[0020] 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.

[0021] [Fig. 1] illustrates an exemplary embodiment of a refrigerator 2 with a refrigeration cycle of a cycle gas comprising, for example, mainly hydrogen and / or helium.

[0022] The refrigerator 2 has a cycle circuit 12 comprising: a mechanism 21, 22 for compressing the cycle gas, at least one member 23, 5 for cooling the cycle gas, a mechanism 24, 25 for expanding the cycle gas and at least one member 5 for reheating the expanded cycle gas.

[0023] The cooling and heating of the cycle gas comprises for example a set of heat exchanger(s). For example a plurality of heat exchangers arranged in series and in which two distinct portions of the cycle circuit circulate simultaneously in counter-current for respectively cooling and for heating the cycle gas. This plurality of heat exchangers forming a cycle gas cooling member and a cycle gas heating member.

[0024] As shown schematically, the compression mechanism comprises, arranged in series, at least one volumetric and alternative compression stage 21 (two stages in series in this example) and at least two centrifugal compression stages 22 (two stages in series in this example).

[0025] The expansion mechanism comprises at least two centripetal type expansion turbines 24 (two in series in this example) of which at least one is mechanically coupled 122 to a centrifugal compression stage 22 so as to provide the compression stage 22 with mechanical work produced during expansion (in this example the two turbines 24 are mechanically coupled respectively to the two centrifugal compression stages). This mechanical coupling is for example achieved by making the turbine and the compressor integral with the same drive shaft. This constitutes a turbo-compressor (i.e. without a compressor drive motor or other active element providing mechanical work to the compressor).

[0026] As illustrated, preferably, the turbines 24 in series are coupled from upstream to downstream respectively with compressors 22 taken in the reverse order (downstream to upstream). That is to say that, for example, at least one turbine 24 is coupled with a compression stage 22 located upstream of a compression stage 22 coupled to another turbine 24 which precedes it in the cycle circuit 12.

[0027] Each volumetric and reciprocating compression stage 21 may comprise or consist of a piston compressor. The compression ratio of the total compression is typically between 10 and 30 between the upstream end and the inlet into the expansion turbines. The piston compressors 21 make it possible to achieve high pressures maximizing the compression ratio. This relatively high compression ratio can be obtained with relatively limited volume flow rates and with good energy efficiency.

[0028] The number of volumetric and alternative compression stage(s) 22 may be between one and eight, for example between three and six.

[0029] The number of centrifugal compression stages 12 may be between one and eight, for example between two and eight.

[0030] A cooler 23 (cycle gas / heat transfer fluid heat exchanger such as water) may be arranged at the outlet of one or more of the centrifugal compression stages 22, for example at least at the outlet of the last centrifugal compression stage (to ensure, for example, isothermal or substantially isothermal compression or to maintain the temperature of the cycle gas below a threshold of, for example, between 65 and 70°C. That is to say that the cycle circuit 12 may be devoid of of a cooling member of the cycle gas at the outlet of at least one of the centrifugal compression stages 22 other than the last centrifugal compression stage 22.

[0031] This architecture with the alternative volumetric compression stage(s) 22 arranged in series upstream of the centrifugal compression stages 22 provides high energy efficiency to the refrigerator 2.

[0032] This structure in fact allows centrifugal over-compression of a relatively light cycle gas (hydrogen for example) which is pre-compressed by piston-type compressors 22. This allows a relative reduction in energy consumption for the compression work.

[0033] These two very different compression technologies (volumetric piston and radial centrifugal) have characteristics (enthalpy as a function of flow rate) that are difficult to combine. In fact, a reciprocating compressor generates flow interruptions (piston) whereas the centrifugal compressor must, by design, receive a continuous minimum flow rate (to avoid its so-called pumping zone which leads to a risk of mechanical breakage).

[0034] The inventors have found that the association of the compression stages in this order nevertheless allows for energy-efficient compression in particular.

[0035] Indeed, the arrangement of the turbo-compressors 22 downstream of the reciprocating compressors 21 allows the turbo-compressors 22 to achieve the theoretical maximum energy efficiency of the compressors 22 by achieving lower specific speeds than in known solutions. Supplying the centrifugal compressors 22 with a relatively high-pressure flow (provided by the reciprocating compressors 21) makes it possible to achieve optimal efficiency due to the reduced volume flow rate at the suction of the centrifugal compressors 22. This advantage is notable even if this configuration was not envisaged because it could generate relatively significant residual axial forces between the turbine wheel on one side and the compressor wheel on the other side of the axis.

[0036] As illustrated, upstream of the last expansion turbine 24, the cycle gas flow can be divided into a first flow supplying the last turbine 24 before returning to an intermediate stage in the compression and a second flow supplying a valve 25, for example of the Joule Thomson type, before returning to the compression inlet.

[0037] As shown schematically in [Fig. 2], each piston compressor may comprise a structure with a piston 121 movable in a compression chamber of the cycle gas, an actuator 7 of the piston (motorized). A system 210 for admitting the cycle gas to be compressed into the compression chamber and a system 211 for discharging the compressed cycle gas out of the compression chamber are provided, for example via appropriate valves or valves. A control member 8 of the system intake 210 and delivery system 211 is provided to control the cylinder capacity and / or the compression ratio of the volumetric and alternative type compression stage 21. The control member 8 comprises for example an electronic controller comprising a microprocessor.

[0038] For example, the control member 8 can control different types of operation. For example, in a first operation the inlet valve is left open or not to admit, for example, 0%, 25%, 50%, 75% or 100% of the flow rate to be treated.

[0039] In a second possible operation, the inlet and outlet valves are opened or closed so as to pass the desired flow rate through the piston.

[0040] In a third possible operation an extension of the volume of the compression chamber can be activated to change the flow rate processed by the piston.

[0041] Similarly, the refrigerator 2 may comprise a system for regulating at least one of the expansion turbines 24 and comprising a throttling valve 13 at the inlet of the expansion turbine and / or a system 14, 15 for bypassing the flow of fluid supplying the turbine 24. This regulation system may be configured to maintain a determined expansion rate at the terminals of each turbine 24.

[0042] As also illustrated in [Fig. 2], the refrigerator 2 may comprise a downstream centrifugal compression regulation system configured to regulate the centrifugal compression stages 22 arranged in series. This regulation system may comprise at least one of: a system 9, 10 for bypassing the fluid flow supplying all or part of the centrifugal compression stages 22, a frequency variator 17, an inlet flow regulator 11 (“IGV”) for the gas flow supplying the centrifugal compression stage 22.

[0043] This downstream compression control system can be configured to control the cycle gas flow rate in the centrifugal compression stages 22 and for example to decrease the cycle gas flow rate in the centrifugal compression stages 22 in response to a decrease in the cycle gas flow rate admitted into the turbines 24.

[0044] As illustrated in [Fig.2], the bypass system may comprise one or more bypass lines 9 and a set of bypass valve(s) 10.

[0045] For example, a first bypass line 9 provided with a valve 10 makes it possible to bypass all the centrifugal compressors 22 in series. A second bypass line 9 provided with a valve 10 makes it possible to bypass several centrifugal compressors 22 in series downstream of at least one first centrifugal compressor 22. A third bypass line 9 provided with a valve 10 makes it possible to bypass a single centrifugal compressor 22, for example a compressor at the downstream end of the series. All or part of these bypass lines 9 can be combined according to the needs for example when starting the installation.

[0046] As illustrated alternatively in [Fig. 3], a respective bypass line 9 provided with a valve 10 may be provided for each compressor 22 (and associated cooler 23 where appropriate). This makes it possible to selectively bypass one or more of the compressors 23 in series and / or to recycle gas around the compressors to improve the energy efficiency of the refrigerator 2.

[0047] As also shown diagrammatically, the cycle circuit 12 preferably comprises a volume 16 for damping the pressure pulsations arranged between the volumetric and reciprocating compression stages 21 and the centrifugal compression stages 22. This damping volume 16 is dimensioned to reduce by a factor of between 10 and 100 the pressure amplitudes of the cycle gas between the outlet of the volumetric and reciprocating compression stage(s) 21 and the inlet of the centrifugal compression stages 22. In the example illustrated, this damping volume comprises, for example, a pressurized buffer storage. Of course, this volume can be achieved by an equivalent dimensioning of the circuitry between these two compression portions (circuit pipes and possible cooling exchanger 23 downstream of the reciprocating compression 21).This damping volume may include one or more internal elements which promote the reduction of pulsations such as, for example, baffles and / or a pipe comprising holes.

[0048] As illustrated in [Fig.l], this refrigerator 2 can be used in a device 1 for liquefying a feed fluid such as hydrogen and / or helium. Such a device 1 (also called a liquefier or liquefaction installation) comprises a feed circuit 3 having an upstream end intended to be connected to a source 2 of feed gas (H2 for example) and a downstream end 23 intended to be connected to a member 4 for collecting the liquefied feed gas (for example at least one cryogenic storage).

[0049] The device 1 comprises a set of heat exchanger(s) 5 in thermal exchange with the supply circuit 3 and cooled by the aforementioned refrigerator 2.

[0050] As illustrated, the device 1 may further comprise at least one pre-cooling system 6 in heat exchange with at least a portion of the heat exchanger assembly 5. This pre-cooling system 6 comprises, for example, a circuit 25 of heat transfer fluid such as liquid nitrogen and / or a refrigerator with a cycle circuit of a mixture of refrigerants comprising, for example, nitrogen and several hydrocarbons. This pre-cooling system 6 may be configured, for example, to pre-cool the feed gas from the initial temperature at the upstream end (ambient temperature, for example) to an intermediate temperature (for example, between 80 and 100K). The refrigerator 2 then ensures the cooling of the feed gas from the intermediate temperature to the temperature of liquefaction.

[0051] The feed gas flow may be variable (particularly in flow rate). This constitutes a heat load to be cooled which is variable. This preferably requires a variable cooling power for the refrigerator. This variable heat load may be measured or determined, for example by measuring or calculating the feed gas flow rate in the feed circuit 3 (or any other representative parameter) and / or a determined change in temperature of a cold end of the refrigerator cycle circuit (indeed, a drop in temperature at the cold end without having changed the refrigerator setpoint indicates that the flow rate to be cooled tends to decrease, therefore less heat load).

[0052] For example, in response to a signal representative of the reduction in the thermal load of the supply fluid circuit 3, the control member 8 of the intake system 210 and of the delivery system 211 of the alternating volumetric compression can be configured to reduce the pressure and / or the mass flow rate at the outlet of this volumetric and alternating type compression. This reduction in pressure and / or volume flow rate can thus be obtained by modifying the cylinder capacity and / or the compression ratio of the stage(s) 21 of volumetric and alternating type compression.

[0053] Thus, the device allows liquefaction of hydrogen by means of a cycle refrigerator carrying out a compression of the cycle gas first of the volumetric and alternating type then a compression of the cycle gas of the centrifugal type, a centripetal expansion of the centrifugally compressed cycle gas and a step of recovering part of the centripetal expansion work for the centrifugal compression.

[0054] The control member 8 and / or the pressure regulation system of the centrifugal compressors and / or the turbine regulation system(s) makes it possible to maintain a given production capacity at the liquefaction device. This or these regulation devices (bypass valve(s) 10 of each or group of compressor(s), throttling valve(s) (13) at the inlet of the cryogenic turbine(s), bypass valve(s) of the turbine(s) or gas recycle at the inlet of the reciprocating cycle compressor and / or control system 8 and control of the suction and / or discharge valves of the reciprocating compressor(s)) make it possible to adapt the refrigeration power to the thermal load.

[0055] The centrifugal compressors and / or turbines may be mounted on magnetic or static and / or dynamic gas bearings. The bearing gas may be recovered and compressed in the compression system.

[0056] The turbochargers can operate in brake mode. That is to say that the compressor 22 does not receive a flow of gas to be compressed (for example via a bypass) but forms a passive brake for the turbine 24 which is coupled to it.

[0057] In this mode of operation, the centripetal turbine 24 is always coupled to the centrifugal compressor 22 but the power supply to the centrifugal compressor is isolated from the rest of the cycle circuit 12 by means of elements interrupting the fluid such as, for example, a valve or a removed pipe element. The fluid circulating through the centrifugal compressor is of the same nature as that passing through the centripetal turbine 24. The fluid circulates in a closed loop around the centrifugal compressor and undergoes in particular the following transformations: compression in the centrifugal compressor, cooling in an exchanger, lowering of the pressure in an expansion element such as a valve. In this operating mode, a bypass 9 allows the continuity of the circuit 12 between the piston compressor 21 and the centripetal turbine 24 without passing through the centrifugal compressor 22 which operates in brake mode. Some turbochargers 22 of the circuit 12 can operate in compression mode ("booster") and some can operate in brake mode.All combinations of brake mode and booster mode of the different turbochargers 22 are possible. The transition from brake mode to compression mode and from compression mode to brake mode of the turbocharger(s) 22 can be carried out either with the refrigerator 2 in operation or with the refrigerator 2 stopped.

[0058] A cycle gas purification unit by adsorption can further be provided between the centrifugal compression and the turbine expansion.

Claims

Claims

1. A refrigerator with a cycle for refrigerating a cycle gas comprising mainly hydrogen and / or helium, the refrigerator having a cycle circuit (12) comprising: a mechanism (21, 22) for compressing the cycle gas, at least one member (23, 5) for cooling the cycle gas, a mechanism (24, 25) for expanding the cycle gas and at least one member (5) for reheating the expanded cycle gas, the compression mechanism comprises at least one stage (21) of volumetric and alternative compression and at least two stages (22) of centrifugal compression arranged in series, the expansion mechanism comprising at least two centripetal expansion turbines (24), at least one of the turbines (24) being mechanically coupled (122) to a centrifugal compression stage (22) so as to provide the compression stage (22) with mechanical work produced during expansion, in which,the at least one stage (21) of alternating volumetric type compression is arranged in series and upstream of the at least two stages (22) of centrifugal compression.,

2. Refrigerator according to claim 1 characterized in that the compression mechanism comprises at least three centrifugal compression stages (22) arranged in series.

3. Refrigerator according to claim 1 or 2 characterized in that the expansion mechanism comprises at least two turbines (24) mechanically coupled (122) respectively to respective centrifugal compression stages (22).

4. Refrigerator according to any one of claims 1 to 3, characterized in that the compression mechanism comprises at least two stages (21) of volumetric and alternative type compression arranged in series.

5. Refrigerator according to any one of claims 1 to 4, characterized in that the expansion mechanism comprises at least one Joule Thomson type expansion valve (25) arranged in series downstream of at least one of the two expansion turbines (24).

6. Refrigerator according to any one of claims 1 to 5, characterized in that the at least one volumetric and alternative type compression stage (21) comprises a piston compressor.

7. Refrigerator according to claim 6, characterized in that the piston compressor comprises a piston (121) movable in a chamber compression of the cycle gas, an actuator (7) of the piston and an intake system (210) of the cycle gas to be compressed in the compression chamber, a delivery system (211) of the compressed cycle gas out of the compression chamber, and a member (8) for controlling the intake system (210) and / or the delivery system (211) to control the mass flow rate and / or the compression ratio of the volumetric and alternative type compression stage (21).

8. Refrigerator according to claim 6 or 7, characterized in that the control member (8) controls the opening or closing of an extension of the volume of the compression chamber, said extension being able to be activated to modify the mass flow rate that the piston compressor must compress.

9. Refrigerator according to any one of claims 1 to 8, characterized in that it comprises a system for regulating at least one of the expansion turbines (24) and comprising a throttling valve (13) at the inlet of the expansion turbine and / or a system (14, 15) for bypassing the flow of fluid supplying the turbine (24).

10. Refrigerator according to claims 8 and 9, characterized in that the regulation system of the at least one expansion turbine (24) is configured to maintain a determined expansion rate at the terminals of the turbine (24).

11. Refrigerator according to any one of claims 1 to 10, characterized in that it comprises a downstream compression regulation system configured to regulate the at least two centrifugal compression stages (22) arranged in series, said downstream compression regulation system comprising at least one of: a system (9, 10) for bypassing the fluid flow supplying all or part of the centrifugal compression stages (22), a frequency variator (17) associated with at least one of the centrifugal compression stages (22), an inlet flow regulator (11) ("IGV") of the gas flow supplying at least one of the centrifugal compression stages (22).

12. A refrigerator according to claims 10 and 11, characterized in that the downstream compression control system is configured to control the cycle gas flow rate in the centrifugal compression stages (22) and for example to decrease the cycle gas flow rate in the centrifugal compression stages (22) in response to a decrease in the cycle gas flow rate admitted to the turbines (24).

13. Refrigerator according to any one of claims 1 to 12, characterized in that the cycle circuit (12) comprises a volume (16) for damping the pressure pulsations arranged between the volumetric and reciprocating compression stages (21) and the centrifugal compression stages (22), for example a pressurized buffer storage, the damping volume (16) being dimensioned to reduce by a factor of between 10 and 100 the pressure amplitudes of the cycle gas between the outlet of the volumetric and reciprocating compression stage(s) (21) and the inlet of the centrifugal compression stages (22).

14. Refrigerator according to any one of claims 1 to 13, characterized in that the cycle circuit (12) is devoid of a member for cooling the cycle gas at the outlet of at least one of the centrifugal compression stages (22) other than the last centrifugal compression stage (22).

15. Device for liquefying a feed fluid such as hydrogen and / or helium comprising a feed fluid circuit (3) having an upstream end intended to be connected to a source (2) of feed gas and a downstream end (23) intended to be connected to a member (4) for collecting the liquefied feed gas, the device (1) comprising a set of heat exchanger(s) (5) in heat exchange with the feed fluid circuit (3), the device (1) comprising at least one refrigerator (2) in heat exchange with at least part of the set of heat exchanger(s) (5), the refrigerator (2) being in accordance with any one of claims 1 to 3.

16. 1H-. Liquefaction device according to claim 15, the refrigerator (2) being in accordance with claim 7, characterized in that, in response to a signal representative of the reduction in the thermal load of the supply fluid circuit (3), the control member (8) of the intake system (210) and of the discharge system (211) is configured to reduce the pressure and / or the mass flow rate at the outlet of the volumetric and alternative compression stage (21) by modifying the mass flow rate and / or the compression ratio of the volumetric and alternative compression stage (21), the signal representative of the reduction in the thermal load of the supply fluid circuit (3) being for example provided by a member for determining the flow rate and / or the characteristics of the gas flow supplying the device and / or a measurement of a determined change in temperature of a cold end of the refrigerator cycle circuit (12) at equal operation and / or a measurement of a determined change in temperature on the supply fluid circuit at equal operation, for example downstream of the set of heat exchangers and upstream of an expansion valve.

17. A method of liquefying a feed fluid, for example hydrogen, using a liquefaction device according to any one of claims 15 or 16, comprising, firstly, volumetric and reciprocating compression of the cycle gas and then subsequently, centrifugal compression of the cycle gas, centripetal expansion of the centrifugally compressed cycle gas and a step of recovering part of the centripetal expansion work for the centrifugal compression.

18. Method according to claim 17, characterized in that it comprises a step of regulating the mass flow rate of compressed cycle gas in the volumetric and reciprocating type compression as a function of the thermal load of the feed gas flow and a step of regulating the flow rate of cycle gas in the centripetal expansion and in the centrifugal compression as a function of the mass flow rate of compressed cycle gas in the volumetric and reciprocating type compression.

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