Installation for pumping cryogenic fluid and filling station comprising such an installation

Abstract

Disclosed is a cryogenic fluid pumping installation (1) that comprises a leak-tight enclosure (13) intended to contain a bath of cryogenic fluid, the enclosure (13) housing a compression chamber (3) communicating with the bath and a movable piston (5) for compressing the fluid in the compression chamber (3), the piston (5) being mounted at a first end of a rod (50), the installation (1) further comprising a drive mechanism (21) for driving a second end of the rod (50) reciprocally in a longitudinal direction (A), the drive mechanism (21) comprising a motor (121) provided with a rotary shaft (211) and a mechanical conversion system (212) for converting the rotary motion of the shaft (211) into a linear motion. In an operating configuration of the installation (1), the longitudinal direction (A) of movement of the rod (50) of the piston is vertical and the motor (21) is rigidly affixed to an upper frame (6, 26). The installation (1) is characterised in that the mechanical conversion system (212) is also rigidly affixed to an upper frame (6, 16) that includes the frame (6, 26) of the motor (121) or a separate frame rigidly linked to the frame (6, 26) of the motor (121).

Description

[0001] The invention relates to a cryogenic fluid pumping installation and to a filling station comprising such an installation.

[0002] The invention relates more particularly to a cryogenic fluid pumping installation comprising a sealed enclosure intended to contain a bath of cryogenic fluid, the enclosure housing a compression chamber communicating with the bath and a movable piston to ensure the compression of the fluid in the compression chamber, the piston being mounted at a first end of a rod, the apparatus comprising a mechanism for driving a second end of the rod in a back-and-forth movement in a longitudinal direction of movement, the drive mechanism comprising a motor provided with a rotating shaft and a mechanical transformation system converting the rotational movement of the rotating shaft into a translational movement, in the operating configuration of the installation, the longitudinal direction of movement of the piston rod being vertical, the motor being rigidly fixed to an upper frame.

[0003] A classic solution for actuating a reciprocating piston pump uses a motor and a mechanical system for transforming the movement of the motor's rotating shaft into translational movement (connecting rod / crank system and / or reducer and / or gearbox).

[0004] Most known cryogenic pumps operate with a horizontal piston axis. This is possible with a vacuum insulated cold end.

[0005] In hydrogen refueling stations, the pump must be available for pumping 24 hours a day. Therefore, it is best to place the cold end in a vacuum-insulated cryogenic liquid bath ("sump") ("dewar") to ensure that it remains cold. A vertical orientation of the piston is more appropriate in this case.

[0006] In this case, some adaptations are necessary to optimally support the drive actuator and the pump (motor and associated mechanism). A cardan system can be used to transmit the torque from the rotational output of the motor gearbox to the crank of the mechanical unit which transforms the rotational movement provided by the motor into a reciprocating translational movement of the piston rod. This allows for optimal assembly without requiring very restrictive tolerances.

[0007] However, in this configuration, a torque is transferred through the cardan shaft to the mechanism for transforming the rotational movement into translation. There is in fact no satisfactory counter-torque system. The mechanism casing will have to withstand this torque. The torque will thus be transferred through the entire pumping structure. This is not acceptable, particularly with regard to the mechanical strength of the tank containing the bath and the overall strength of the structure.

[0008] Even when sizing these elements accordingly, risks remain regarding potential vibration and fatigue problems.

[0009] With a hydraulic solution, it's relatively easy to position the pump vertically because the hydraulic cylinder is relatively small. The enormous power unit, on the other hand, can be offset several meters. However, the overall layout and efficiency are not suited to the application.

[0010] A roller screw linear actuator solution is also easy to implement due to its compactness. However, this solution is not suitable for high-pressure cryogenic applications due to low efficiency and reliability.

[0011] Document US2018 / 180035 discloses an installation (10) for pumping cryogenic fluid according to the preamble of claim 1.

[0012] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0013] To this end, the installation according to the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that the mechanical transformation system is also rigidly fixed to an upper frame which comprises the engine frame or a separate frame rigidly connected to the engine frame.

[0014] Furthermore, embodiments of the invention may include one or more of the following features: the upper frame of the motor comprises a first set of support beam(s), the upper frame of the mechanical transformation system comprising a second set of support beam(s), the second set of beam(s) being rigidly connected to the first set of support beam(s), the motor and the mechanical transformation system are rigidly fixed respectively on two separate beam portions secured or rigidly connected to a common beam extending in a longitudinal structural direction, the two beam portions are connected transversely to the common beam, two beam portions are located transversely on either side of the common beam, at least one of the two beam portions is cantilevered to the common beam,at least one of the two beam portions is connected to the common beam via a removable mechanical connection provided with a positioning system making it possible to adapt the transverse and / or longitudinal position of said portion relative to the common beam before fixing this position, the rotating shaft is coupled to the mechanical transformation system via an axis comprising a connection system such as a rigid connection or a universal joint, the motor is suspended from its upper frame, the mechanical transformation system is suspended from its upper frame, the sealed enclosure is suspended from the mechanical transformation system, the installation comprises several enclosures each housing a compression chamber, a movable piston, the pistons being actuated by respective drive mechanisms each composed of a motor and a mechanical transformation system,said engines and mechanical transformation systems being fixed to the same upper frame or to separate frames rigidly connected to each other, the installation comprises a tank of liquefied gas, in particular hydrogen, said tank being fluidically connected by a set of pipes to the enclosure, these pipes being configured to supply the compression chamber with fluid to be compressed and recover the fluid evaporated in the enclosure, the mechanical system converting the rotational movement of the rotating shaft into a translational movement of the piston rod is of the connecting rod and crank type, the mechanical transformation system is housed in a casing fixed to the upper frame, the engine is housed in a casing fixed to the upper frame, the installation is of the single-stage compression type, that is to say that the fluid is compressed only once between an intake system and an evacuation system in the compression chamber,the installation is of the two-stage compression type, that is to say that the fluid is compressed twice between an intake system and an evacuation system, the installation comprising two compression chambers, an intake system communicating with a first compression chamber, a transfer system communicating with the first and second compression chambers and configured to allow the transfer of compressed fluid in the first compression chamber to the second compression chamber, the movable piston alternately ensuring the compression of the fluid in the first and second compression chambers according to its direction of movement an evacuation system communicating with the second compression chamber, the compression of the fluid in the compression chamber is obtained by traction or compression of the rod.

[0015] The invention also relates to a station for filling pressurized gas tanks or pipes comprising a source of liquefied gas, in particular a liquefied hydrogen tank, a withdrawal circuit having a first end connected to the source and at least one second end intended to be connected to a tank to be filled, the withdrawal circuit comprising a pumping installation conforming to any one of the characteristics above or below.

[0016] 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.

[0017] Other features and advantages will become apparent upon reading the following description, given with reference to the figures in which: [ Fig.1 ] represents a perspective, schematic and partial view, illustrating a first example of a possible embodiment of a pumping installation according to the invention, [ Fig.2 ] represents a front view, schematic and partial, illustrating the first example of embodiment of the installation and comprising a cryogenic fluid tank, [ Fig.3 ] represents a schematic and partial sectional view, illustrating a detail of the installation and in particular an example of compression chamber structure, [ Fig.4 ] represents a schematic and partial perspective view from above, illustrating a detail of the frame structure of the installation in another possible embodiment, [ Fig.5 ] represents a front view, schematic and partial, illustrating a second example of the installation, [ Fig.6 ] represents a front view, schematic and partial, illustrating a third example of the installation, [ Fig.7 ] represents a top view, schematic and partial, illustrating a fourth example of the installation, [ Fig.8 ] represents a schematic and partial side view, illustrating a fifth example of the installation, [ Fig.9 ] represents a schematic and partial view, illustrating an example of a filling station using such a compression device, [ Fig.10 ] represents a perspective, schematic and partial view, illustrating an example of the support structure of the installation frames. Fig.11 ] represents a perspective, schematic and partial view of another example of installation.

[0018] The cryogenic fluid pumping installation 1 shown comprises a sealed enclosure 13 intended to contain a bath of cryogenic fluid. The enclosure 13 can be thermally insulated under vacuum and houses a compression chamber 3 communicating with the bath and a movable piston 5 to ensure the compression of the fluid in the compression chamber 3 cf. [ Fig.3 ].

[0019] The piston 5 is mounted at a first end of a piston rod 50. The apparatus 1 comprises a mechanism 21 for driving a second end of the rod 50 in a back-and-forth movement in a longitudinal direction A of movement.

[0020] The drive mechanism 21 comprises a motor 121 (with, where appropriate, a gearbox or other) provided with a rotating shaft 211 and a mechanical transformation system 212 converting the rotational movement of the rotating shaft 211 into a translational movement of the rod 50. The mechanical system 212 converting the rotational movement of the rotating shaft 211 into a translational movement of the rod 50 of the piston may be of the connecting rod and crank type and housed in a casing.

[0021] The rotating shaft 211 of the motor 121 is coupled to the mechanical transformation system 212 via an axis comprising a connection system such as a rigid connection or a universal joint for example.

[0022] A cardan coupling can allow for greater assembly tolerances.

[0023] The cardan coupling between the two units also allows the “useful” torque to be transferred optimally with relatively easy maintenance.

[0024] These elements (engine 121 and mechanical transformation system 212) can be housed in respective casings.

[0025] The housing of the 212 motion transformation system can be easily removed to access the cold end placed vertically under the mechanism (under a crank, in particular in the case of a connecting rod and crank mechanism).

[0026] As illustrated, in the operating configuration of the installation 1 the longitudinal direction A of movement of the rod 50 of the piston is vertical. The motor 121 is rigidly fixed to an upper frame 6, 26.

[0027] The mechanical transformation system 212 is also rigidly attached to an upper frame which may be the same frame 6, 26 of the motor 121 or a separate frame rigidly connected to the frame 6, 26 of the motor 121.

[0028] This makes it possible to mount (in particular suspend) the entire drive mechanism 21 rigidly above the enclosure 13 via a structure making it possible to support the motor 121 and the transformation mechanism 212 without transferring harmful torque into the structure.

[0029] In particular, the motor 121 (and its casing if applicable) can be suspended from its frame 6, 26. In particular, the motor 121 and its casing can be fixed by its upper part to a lower face of the upper frame 26 (for example by screwing or otherwise).

[0030] Likewise, the mechanical transformation system 212 (and its casing where applicable) can be suspended from its upper frame 16, in particular fixed by its upper part to the frame (same for example by screwing or other).

[0031] Preferably each element 121, 212 can be removed from the frame 16, 26 to which it is fixed and independently of the other element 121, 212. This is advantageous for maintenance.

[0032] This structure can support the container 13 suspended for greater flexibility. That is, an upper end of the container 13 can be suspended from a lower end of the mechanical transformation system 212 (in particular from its casing) by a connecting member 9 such as one or more axes and / or a sleeve. The lower end of the container 13 can thus be located above the ground without resting on a lower support.

[0033] Indeed, as described in more detail below, the cryogenic pipes connecting this container 13 and a reservoir 17 of cryogenic liquid can be flexible to absorb thermal contractions and allow minor alignment defects to be tolerated.

[0034] In particular, the motor 121 and its casing can be rigidly connected to their upper frame 26, 6. Similarly, the mechanical transformation system 212 and its casing can be rigidly connected to their upper frame 16, 6.

[0035] The upper frame of the engine 121 may comprise a first set of horizontal support beam(s) 6, 26 connected to a supporting structure 60 which may comprise vertical feet resting on the ground.

[0036] Similarly, the upper frame of the mechanical transformation system 212 may comprise a second set of support beam(s) 6, 16.

[0037] As illustrated, the second set of beam(s) is rigidly connected to the first set of support beam(s) 6, 26. The two sets of beam(s) may be at least partly common. For example, the motor 121 and the mechanical transformation system 212 may be connected to two separate portions 16, 26 of the same beam (for example transverse) connected to a beam 6 (extending for example in a longitudinal direction of structure).

[0038] The two beam portions 26, 16 can be connected transversely to the common beam 6.

[0039] As illustrated, the two beam portions 26, 16 may be located transversely on either side of the common beam 6 (in particular at the same longitudinal position along the longitudinal structural beam 6).

[0040] As illustrated, at least one of the two beam portions 26, 16 can be cantilevered to the common beam 6. Thus, these two portions 16, 26 and the beam 6 form a cross-shaped structure, in particular a Latin cross.

[0041] These upper frames 6, 16, 26 can be upper beams held in height via a set of feet or a hyperstatic structure. See for example the schematic representation of the [ Fig.10 ].

[0042] As illustrated, the supporting structure 60 of the upper beams 6, 16, 26 (frames) may comprise an upper structure carried by feet and forming a support for each of the beam portions 16, 26 on which the motor and the transformation mechanism are suspended respectively (on either side of the common beam 6). For example, the terminal ends of these beam portions 16, 26 are connected to upper elements (uprights or horizontal axes for example) carried by feet and forming the supporting structure 60. In the example illustrated, the two ends of the common beam 6 and the end of one of the two transverse beam portions are supported on the structure 60 (the other end of the beam portion may be cantilevered).Of course, it is possible to envisage a configuration in which the four ends of the frame 6, 16, 26 (i.e. the four ends of the “cross” formed by the upper frame) are connected to the upper part of a supporting structure 60 (for example four horizontal uprights forming an upper frame).

[0043] As schematized in the variant embodiment of the [ Fig.4 ] at least one of the two beam portions (in particular that 16 to which the mechanical transformation system 212 is attached) can be connected to the common beam 6 via a removable mechanical connection 8 and preferably provided with a positioning system making it possible to adapt the transverse and / or longitudinal position of said portion 16 relative to the common beam 6 before fixing this position. For example, a flexible semi-circular self-centering fixing system can be envisaged. This flexible fixing system is of the type allowing a certain movement for optimal assembly, for example a semi-circular groove system (self-centering). Other fixing devices can be envisaged.

[0044] The motion transformation system 212 and in particular its casing can thus be on a small part of beam 16 which can be mounted independently and dismantled on the main beam 6.

[0045] In the example of the [ Fig.2 ] the installation 1 comprises a tank 17 of liquefied gas, in particular hydrogen. The tank 17 is fluidically connected by a set of pipes 10, 11 to the enclosure 13 and configured to supply the compression chamber 3 with fluid to be compressed and recover the fluid evaporated in the enclosure 13.

[0046] This tank 17 can rest on the ground. As mentioned previously, the pipes 10, 11 can include flexible portions.

[0047] In the above examples, the installation 1 comprises a single motor 121, a single mechanical transformation system 212 and a single container 13. Of course, as shown diagrammatically in [ Fig.8 ], the installation 1 could comprise several enclosures 13 each housing a compression chamber, a movable piston, the pistons being actuated by respective drive mechanisms 21 each composed of a motor 121 and a mechanical transformation system 212, said motors 121 and mechanical transformation systems 212 being able to be fixed to the same upper frame 6, 16, 26 or to separate frames rigidly connected to each other.

[0048] A separation space 12 may be provided on the longitudinal structural beam 6 between two adjacent units to facilitate maintenance. The entire mechanical transformation system 212 of its casing and the corresponding support beam 16 of one of the two units may be temporarily fixed at this portion during maintenance.

[0049] The structure of the installation has many advantages.

[0050] In addition to a transmission of movement without harmful torque (no force cycling throughout the structure; less vibration expected), the structure is particularly suitable for easy maintenance (for example, via the dismantling of a suspended element, in particular a casing to access the mechanism(s)).

[0051] The drive mechanism (motor + possibly reducer or gearbox) must not be dismantled during maintenance on the cold side of the cryogenic pumping part. The maintenance frequency of the motor part 121 is generally lower than that of the cold drive part. The proposed structure allows access to the cold part without dismantling the motor part 121 (visual inspection, cleaning, replacement of seals, lubrication, etc.).

[0052] In the proposed configuration, the engine part 121 does not need to carry the weight of the transmission part 212 and the cold part thanks to the suspended structure described above.

[0053] Installation 1 is compact with a low-to-the-ground layout. This is suitable for integration into a filling station.

[0054] The 121 motor and the associated reducer can be standard elements, in particular with an explosion-proof structure or increased safety.

[0055] The motor 121 and the transformation system 212 can be placed relatively according to different configurations, in particular horizontally, vertically, with the shaft 211 rotating in this axis or perpendicularly according to the model of the known reduction system 212 (helical, helical bevel, worm screw, helical parallel shaft, right angle reduction).

[0056] In the example of the [ Fig.1 ] and the [ Fig.2 ] the motor 121 is vertical and perpendicular to the axis 211 which is connected to the mechanical movement transformation system 212.

[0057] In the configuration of the [ Fig.5 ], the motor 121 and output shaft 211 are horizontal and oriented transversely to the longitudinal structural beam 6. This configuration saves space under the upper frame 6, 16, 26.

[0058] In the configuration of the [ Fig.6 ], the axis 211 connected to the mechanical transformation system 212 is located relatively lower than the motor 121 (via the structure of a reduction box or gearbox at the output of the motor 121). This configuration saves space under the drive unit and reduces the height of the connection 9 between the container 13 and the vertical support.

[0059] In the configuration of the [ Fig.7 ], the motor 121 is arranged horizontally and parallel to the longitudinal structural beam 6. This reduces the space requirement under the drive system as well as transversely.

[0060] The motor assembly 121 and its possible illustrated reducer from which the rotating shaft 211 protrudes can, if necessary, be advantageously replaced by a torque motor (therefore without reduction box or gearbox). In this case, there is no oil problem due to lubrication. In addition, in this case the assembly is more compact and of reduced mass. In addition, such a motor assembly has more flexibility on the speed adjustment (speed profile and rotation speed in particular).

[0061] There [ Fig.3 ] schematically illustrates an example of a compression chamber (a single compression stage) with an intake system 2 communicating with the compression chamber 3 configured to allow the entry of fluid to be compressed into the compression chamber 3, a movable piston 5 to ensure the compression of the fluid in the compression chamber 3, and an evacuation system 7 communicating with the compression chamber 3 and configured to allow the exit of compressed fluid. The compression of the fluid in the compression chamber can be obtained by traction or compression of the rod 50.

[0062] Of course, the invention also applies to pumps with two compression stages (for example two compression chambers and two compression stages respectively in the two directions of translation of the piston).

[0063] There [ Fig.9 ] represents an example of a filling station for pressurized gas tanks or pipes comprising a source 17 of liquefied gas, in particular liquefied hydrogen, a withdrawal circuit 18 having a first end connected to the source and at least one second end intended to be connected to a tank 190 to be filled. The withdrawal circuit 18 comprising a compression apparatus 1 conforming to the installation according to any one of the characteristics above.

[0064] Although the enclosure 13 is suspended from the mechanical transformation system 212, itself suspended from its upper frame, as shown diagrammatically in [ Fig.1 ], it is possible to envisage providing one or more feet 20 connecting the enclosure 13 to the ground via a flexible and / or adjustable connection 201. This can be during maintenance operations and / or in normal operating situations, for example, to better maintain the enclosure 13 and absorb any vibrations, for example.

[0065] Alternatively or cumulatively, the enclosure 13 can rest (for example via its lower end or bottom) on the upper surface of a support 202, for example with feet (cf [ Fig.11 ]. This makes it possible to take up part of the forces transmitted to the container 13.

[0066] As illustrated in [ Fig.11 ], the upper frame(s) to which the motor 121 and the mechanical transformation system 212 are attached may be carried by a hyperstatic structure 60 comprising, for example, beams forming feet.

[0067] This hyperstatic structure forms, for example, a frame and can be provided with a base placed on the ground and on which the support 202 or feet 20 for holding the container 13 can rest.

[0068] Such a structure 60 may be provided for each pumping assembly comprising a container 13, a motor, and a piston drive mechanism 21.

Claims

1. Installation (1) for pumping cryogenic fluid comprising a fluidtight enclosure (13) intended to contain a bath of cryogenic fluid, the enclosure (13) housing a compression chamber (3) communicating with the bath and a piston (5) that is able to move in order to compress the fluid in the compression chamber (3), the piston (5) being mounted at a first end of a rod (50), the installation (1) comprising a drive mechanism (21) driving a second end of the rod (50) in a back and forth movement in a longitudinal direction (A) of travel, the drive mechanism (21) comprising a motor (121) equipped with a rotary shaft (211) and a mechanical conversion system (212) converting the rotational movement of the rotary shaft (211) into a translational movement, in the configuration of operation of the installation (1), the longitudinal direction (A) of travel of the piston rod (50) being vertical, the motor (21) being fixed rigidly to an upper mounting structure (6, 26), characterized in that the mechanical conversion system (212) is also fixed rigidly to an upper mounting structure (6, 16) which comprises the mounting structure (6, 26) for the motor (121) or a separate mounting structure rigidly connected to the mounting structure (6, 26) for the motor (121).

2. Installation according to Claim 1, characterized in that the upper mounting structure for the motor (121) comprises a first support beam(s) assembly (6, 26), the upper supporting structure for the mechanical conversion system (212) comprising a second support beam(s) assembly (16), the second beam(s) assembly being rigidly connected to the first support beam(s) assembly (6, 26).

3. Installation according to Claim 2, characterized in that the motor (121) and the mechanical conversion system (212) are rigidly fixed respectively to two distinct beam portions (26, 16) which are integral with or rigidly connected to a common beam (6) extending in a longitudinal direction of the structure.

4. Installation according to Claim 3, characterized in that the two beam portions (26, 16) are connected transversely to the common beam (6).

5. Installation according to Claim 4, characterized in that the two beam portions (26, 16) are located transversely one on each side of the common beam (6).

6. Installation according to any one of Claims 3 to 5, characterized in that at least one of the two beam portions (26, 16) is connected cantilever-fashion to the common beam (6).

7. Installation according to any one of Claims 3 to 6, characterized in that at least one of the two beam portions (26, 16) is connected to the common beam (6) via a disconnectable mechanical connection (8) equipped with a positioning system to allow the transverse and / or longitudinal position of said portion relative to the common beam (6) to be adapted before this position is fixed.

8. Installation according to any one of Claims 3 to 6, characterized in that the rotary shaft (211) is coupled to the mechanical conversion system (212) via an axle comprising a connecting system such as a rigid connection or a Cardan joint.

9. Installation according to any one of the preceding claims, characterized in that the motor (121) is suspended from its upper mounting structure (6, 26).

10. Installation according to any one of the preceding claims, characterized in that the mechanical conversion system (212) is suspended from its upper mounting structure (16).

11. Installation according to any one of the preceding claims, characterized in that the fluidtight enclosure (13) is suspended from the mechanical conversion system (212).

12. Installation according to any one of the preceding claims, characterized in that it comprises several enclosures (13) each housing a compression chamber, a mobile piston, the pistons being actuated by respective drive mechanisms (21) each made up of a motor (21) and of a mechanical conversion system (212), said motors (21) and mechanical conversion systems (212) being fixed to the one same upper mounting structure or to distinct mounting structures that may potentially be rigidly joined to one another.

13. Installation according to any one of Claims 1 to 12, characterized in that the enclosure (13) rests on a lower base such as the ground via a support (202) and / or a set of leg(s) (20).

14. Installation according to any one of Claims 1 to 13, characterized in that the upper mounting structure (6, 16, 26) to which the motor (21) and / or the mechanical conversion system (212) are fixed is supported by a statically indeterminate structure (60) comprising beams forming legs.

15. Installation according to any one of the preceding claims, characterized in that it comprises a tank (17) of liquefied gas, notably of hydrogen, said tank (17) being fluidically connected by a set of pipes (10, 11) to the enclosure (13), these pipes being configured to supply the compression chamber with a fluid that is to be compressed and to recover the fluid that has vaporized in the enclosure (13).

16. Station for filling tanks or pipes with pressurized gas and comprising a source (17) of liquefied gas, notably a tank of liquefied hydrogen, a withdrawal circuit (18) having a first end connected to the source and at least one second end intended to be connected to a tank (190) to be filled, the withdrawal circuit (18) comprising a pumping installation (1) according to any one of Claims 1 to 15.

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