KR20240013111A - Compression devices, and charging stations including such devices - Google Patents

Abstract

The present invention relates to a device (1) for compressing cryogenic fluid, comprising: a sealed enclosure (13) intended to contain a container (16) of cryogenic fluid; Compression chambers (3, 4) in communication with the vessel; an intake system (2) in communication with the compression chambers (3, 4) and configured to enable introduction of fluid to be compressed into the compression chamber (3); and a movable piston (5) for compressing the fluid in the compression chambers (3, 4), wherein the device (1) is configured to communicate with the compression chambers (3, 4) and enable discharge of the compressed fluid. It further comprises an exhaust system (7), wherein the piston (5) is mounted on the first end of the rod (50), and the device (1) is configured to drive the rod (50) with a back and forth movement along the longitudinal direction (A). It includes a mechanism 21 for driving mechanism 21, a motor 121 having a rotating shaft 211, and a second end of a rod 50 connected to the rotational movement of the rotating shaft 211. It comprises a mechanical system (212, 213) which translates into a translational movement of the head (8) sliding along the longitudinal direction (A), the head (8) comprising two fixed guides located on both sides of the head (8). Characterized in that it is mounted to slide and be guided by a rail (9), wherein the head (8) and/or one rail (9) includes an elastic part (10), the elastic part (10) being longitudinally ( It is characterized in that it is configured to generate a transverse force against A) on the rail or rails (9).

Description

Compression devices, and charging stations including such devices

The present invention relates to compression devices and filling stations incorporating such devices. Such devices are, for example, cryogenic pumps, especially for pumping liquefied hydrogen.

More specifically, the present invention relates to a device for compressing cryogenic fluid, the device comprising: a sealed enclosure intended to contain a bath of cryogenic fluid; a compression chamber in communication with the vessel; an intake system in communication with the compression chamber, configured to enable introduction of fluid to be compressed into the compression chamber; It includes a movable piston to ensure compression of the fluid in the compression chamber, the device further comprising an exhaust system configured to communicate with the compression chamber and enable discharge of the compressed fluid, the piston being connected to a rod. Mounted at the first end, the device includes a mechanism for driving the rod in a longitudinal back-and-forth movement, the drive mechanism comprising a motor with a rotating shaft, and a motor for rotating the rotating shaft at a second end of the rod. is connected and includes a mechanical system that converts the translational movement of the longitudinally sliding head.

Drive by a connecting rod-crank mechanism is a known operating solution for cryogenic piston pumps. Most of these pumps operate using oil splash lubrication to guide the piston rod. This architecture is well suited to horizontal piston rod configurations because oil leakage is very limited. The piston rod may be guided by plain bearings or anti-friction strips (eg bronze plates).

In the case of vertically configured cryogenic pumps, it is very difficult to perform this droplet oiling method for the mobile conversion mechanism. Specifically, the cold end of the pump is placed within a tank (commonly referred to as a sump), and an articulated device is placed vertically above it. Due to the linear reciprocating movement, oil leakage occurs along the piston rod. Falling of remains onto the cryogenic section is not permitted for safety reasons.

One solution is to use a leak capture and recirculation system (with pumps, filters, etc.). These solutions are unsatisfactory.

One solution is to use an oil-free linear guide mechanism (eg roller carriage, ball bearing sleeve, etc.) mounted on the side that receives the generated transverse forces. These architectures are subject to large operating forces, limiting their service life and requiring frequent maintenance. Additionally, these solutions can cause high temperature rises that require the plant to be shut down. Additionally, the piston stroke is relatively short compared to the load (acting force). The sliding head size is close to the stroke size. Additionally, due to the asymmetry of the mechanism, the acting force is imperfectly distributed. To accommodate the force, a plurality of sliding heads can be provided or a plurality of guides on one side can be used, together with additional mechanical coupling devices (ball joints to enable assembly). However, this does not completely solve the problem.

The object of the present invention is to overcome some or all of the disadvantages of the prior art described above.

For this purpose, the compression device according to the invention, which also conforms to the general definition given in the preamble above, essentially consists in the head being slidably mounted and guided by two fixed guide rails located on both sides of the head. Characterized in that the head and/or rail includes an elastic portion, and the elastic portion is configured to generate a force transverse to the longitudinal direction on the rail or rails.

Additionally, embodiments of the invention may include one or more of the following features:

- the compression of the fluid in the compression chamber is achieved by traction or compression of the rod, which causes a transverse thrust of the head on one of the rails in the direction transverse to the longitudinal direction, The force generated by the elastic part is in the opposite direction to this thrust;

- the elastic part is configured to generate a transverse force on the rail or rails with an intensity that, in absolute value, is below or above the maximum intensity of the thrust force;

- The elastic part is located between the central area of the head and one of the two rails;

- the elastic part is located between one of the two rails and the fixed support of said rail;

- the elastic part contains springs or deformable zones and is prestressed;

- In the operating configuration, the rod is movable in a back and forth movement in the vertical longitudinal direction;

- The mechanical system that converts the rotational movement of the rotating shaft into the translational movement of the carriage is of the connecting rod and crank type;

- a mechanical system for converting the rotational movement of the rotating shaft into a translational movement of the head, connected to the central section of the head via a ball joint or pivot connection, the connection being located on a longitudinal straight line passing through the axis of translation of the rod, , the straight line also intersects the straight line passing through the rotating shaft of the motor;

- The head is guided via a guide system with or without rolling element(s), for example via a system with rollers and/or balls and/or sliding rollers, or via a precision rail(s) type system, It is slidably mounted within the guide rail;

- the device is of the type with one compression stage, i.e. the fluid is compressed only once between the intake and exhaust systems;

- the device is of a type with two compression stages, i.e. the fluid is compressed twice between the intake system and the exhaust system, the device comprising two compression chambers, the intake system communicating with the first compression chamber, The transport system is in communication with the first and second compression chambers and is configured to transport fluid compressed in the first compression chamber to the second compression chamber, wherein the movable piston is configured to move the first and second compression chambers in the direction of its movement. alternately compressing the fluid in the compression chambers, and the exhaust system communicates with the second compression chamber;

- The second compression chamber is defined by a part of the body of the piston and the stationary wall of the device.

The invention also relates to a station for filling tanks or pipes with compressed gas, comprising: a source of liquefied gas, in particular liquefied hydrogen; a withdrawal circuit having a first end connected to the source and at least one second end intended to be connected to the tank to be filled, the withdrawal circuit comprising: compression conforming to any one of the above or below features; Includes device.

Additionally, the invention may relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

Additional specific features and advantages will become apparent upon reading the following description given with reference to the drawings, wherein:
Figure 1 shows a schematic partial vertical cross-sectional view showing one embodiment of the structure and operation of a compression device according to the invention;
Figure 2 shows a schematic partial horizontal cross-section of the details of the above-described device with the arrangement level of one end of the sliding head and its vertical guide rail;
Figure 3 shows another schematic partial horizontal cross-sectional view of a detail of the above-described device, showing the rolling elements and at the level of the arrangement of one end of the sliding head and its vertical guide rails;
Figure 4 schematically and partially shows an embodiment of the distribution of the acting force on one end of the sliding head and its guide rails of the device in the traction configuration;
Figure 5 shows a schematic partial cross-section showing details of a possible variant embodiment of the compression chamber of this compression device;
Figure 6 shows a schematic partial cross-sectional view showing details of a possible second variant embodiment of the compression chamber of this compression device;
Figure 7 shows a schematic partial cross-sectional view showing details of a possible third variant embodiment of the compression chamber of this compression device;
Figure 8 shows a schematic partial diagram showing details of the device, showing possible exemplary embodiments of the structure of the elastic part;
[Figure 9] shows a schematic partial diagram representing one embodiment of a charging station using such a compression device.

The schematically shown apparatus 1 for compressing cryogenic fluid comprises a sealed enclosure 13 intended to contain a container 16 of cryogenic fluid (typically liquid in the lower part and gaseous in the upper part). do. The device 1 has at least one compression chamber 3 in communication with a liquid container (in particular, the compression chamber 3 is preferably immersed in the container).

The device 1 is configured to enable introduction of fluid to be compressed into the compression chamber 3 (typically comprising a system of valve(s) and/or orifice(s)) and and a communicating, intake system (2).

The device (1) comprises a movable piston (5) to ensure compression of the fluid in the compression chamber (3), and an exhaust system (7) in communication with the compression chamber (3) configured to enable discharge of the compressed fluid. (typically comprising a set of valve(s) and in communication with an exhaust pipe).

The piston (5) is mounted on the first end of the rod (50). The device 1 comprises a mechanism 21 for driving the rod 50 with alternating back and forth movements in the longitudinal direction A. Typically, the drive mechanism 21 includes a motor 121 with a rotating shaft 211, and converts the rotational movement of the rotating shaft 211 into a translational movement of the head 8 sliding in the longitudinal direction A. It includes mechanical systems 212 and 213 that do. The second end of the rod 50 is connected to the head and receives its actuation.

Head 8 may consist of one or more assembled parts. This head 8 may also be referred to in the literature by the terms “crossmember”, “crossbeam” or “crosshead”.

For example, the piston rod 50 is connected to the head 8 through a coupling portion, such as a rigid connection (e.g. bolted flange type) or a flexible connection (e.g. ball joint or pivot type). It can be connected at one end.

The head (8) is slidably mounted and guided by two fixed guide rails (9). Two rails 9 are located on both sides of the head 8 (on both sides in the direction perpendicular to the longitudinal direction A). The head 8 is guided in translation by a rail 9 and receives traction and thrust forces through one end of the mechanism 21, for example a connecting rod 213 connected to a ball joint or pivot connection ( 11) is connected to the head (8).

As shown, the mechanical system for converting the rotational movement of the rotating shaft 211 into the translational movement of the head 8 includes a connection ( It can be connected to the central section of the head (8) via 11). Additionally, this straight line may also intersect with a straight line passing through the rotation shaft 211 of the motor 210.

As shown in the sections of Figures 2 and 3, each end of the head 8 can be slidably mounted on a rail 9. As can be seen in [FIG. 3], the head 8 can be slidably mounted on the guide rail 9 via a roller and/or ball set 12. The sliding system may be of the precision rail type (preferably oil-free when the axis of the rod is vertical in the position of use) or any other suitable guide system.

For example, a carriage (with rollers or balls) is screwed onto the head 8 and moves with it. The rail 9 itself is fixed, for example, to the frame of the device. Nevertheless, for refueling, a passive (or active) cartridge can be mounted on each carriage.

The head 8 comprises an elastic part 10 configured to generate a force transverse to the longitudinal direction A on the rail or rails 9 .

That is, the elastic portion 10 generates a permanent transverse force on the rail(s) 9.

The compressive movement of the fluid in the compression chamber 3 generates a large acting force within the mechanism (compression of the fluid is achieved during traction of the rod in the figure in Figure 1). During this compression, due to the asymmetry of the mechanism (eccentric type mechanism), the lateral forces on the rail 9 are not symmetrical. In particular, one rail 9 may be loaded transversely more than the other rail (in the non-limiting example shown, the left rail).

According to the above-described arrangement, it is possible to at least partially rebalance these transverse forces in the device 1 .

Specifically, as schematically shown in [FIG. 4], the acting force Fm applied by the movement conversion mechanism 21 is one of the traction component Ft with respect to the rod 50 and the rail 9. Induces a transverse thrust component (F1) directed toward . The elastic part 10 is configured to generate a continuous acting force F2 on this same rail 9 in the direction opposite to this thrust F1 and at least partially compensate for this (e.g. acting force F2 ) is the size to reduce the thrust force (F1) by half). It should be noted that the acting force F2 may also be generated on other rails 9; This has no particular effect on the proper functioning of the device.

It should be noted that the intensity of this acting force F2 generated by the elastic part is preferably constant, whereas the thrust F1 has an intensity that varies periodically during the movement. The value of F2 can be chosen to partially compensate for the maximum intensity of F1 during the cycle.

Maximum thrust force (when operating at low loads, the spring force will exceed the thrust force.

In other words, the elastic part 10 permanently implements the “transverse compensating load”. Accordingly, the final force produced by the mechanism is limited, making it possible to limit stresses in the actuation phase that produces the maximum force. A more appropriate balancing or clipping of the transverse forces is achieved.

Therefore, instead of using a single guide rail on one side of the head 8 (on the side receiving the force), this solution, together with the elastic member 10, provides a second guide rail, which makes it possible to reduce the lateral force. Guide rails are provided.

It should also be noted that this arrangement also makes it possible to deal with possible problems of alignment and spacing (assembly tolerances) between the two rails 9, in order to ensure that the assembly is assembled correctly. As schematically shown, the elastic part 10 can be positioned between one of the two rails 9 and the central region of the head 8. This elastic portion 10 may comprise a prestressed spring, or a prestressed deformable region, or any other member that generates an appropriate acting force. As schematically shown in Figure 8, this elastic portion may comprise a spring formed as a loop-shaped portion (e.g., having two lobes) of a portion of the body of the head 8. there is.

It should be noted that the elastic portion 10 may be integrated within (or comprised of) the head 8 . Elements 8 and 10 may be separate parts, or may be one and the same part.

In the embodiment of [FIG. 1] as well as the embodiment of [FIG. 6], fluid compressive force is obtained by (increasing) the traction of the rod 50.

Of course, this is by no means limiting. Therefore, as shown in [FIG. 5], fluid compression force can be obtained by thrust (reduction) of the rod 50. In this case, the lateral forces are reversed in relation to the above explanation. In this case, the elastic part 10 (by moving this elastic part on the other side of the head or by changing the structure of the elastic part 10 so that its acting force is directed against the excess acting force on the relevant side). The acting force (F2) can also be simply reversed.

It should be noted that in the embodiment of Figure 6, the piston 5 comprises a tubular portion mounted around the fixed central guide 15. The longitudinal end of the central guide 15 , which forms a stationary wall, defines a part of the compression chamber 3 with the tubular part of the piston 5 .

In the above-described embodiment, device 1 is of the type with one compression stage (the fluid is compressed only once). Of course, the invention applies in the same way to compression devices with two compression stages (the fluid undergoes two compressions in succession). [Figure 7] shows one embodiment of a compression structure with two compression stages. Accordingly, the device 1 may comprise a tubular piston 5 which interacts with a fixed chamber or a closed tubular cavity 14 at its lower end to define two compression chambers 3 , 4 . The intake system (2) communicates with the first compression chamber (3). The architecture is in communication with the first compression chamber (3) and the second compression chamber (4) and is configured to enable transfer of fluid compressed in the first compression chamber (3) to the second compression chamber (4). , including the transfer system 6 (valves, etc.). The movable piston 5 alternately compresses, in the direction of its movement, the fluid in the first compression chamber 3 (toward the second chamber 4) and the fluid in the second compression chamber 4. The exhaust system (7) communicates with the second compression chamber (4).

The device 1 will have the following operating characteristics: a piston stroke of 40 to 160 mm, a motor rotation speed of about 80 rpm to 500 rpm (for the piston 5, corresponding to a frequency of 1.3 Hz to 8.5 Hz) You can. For the traction force (Ft), the thrust force (F1) may be about 10 to 20% of Ft, while the opposing force generated by the elastic member 10 may be about 5 to 10% of Ft.

The above-mentioned solution has many advantages.

Accordingly, the maximum load peak within the mechanism can be limited. Accordingly, the service life of the guide system subjected to this force can be increased.

The architecture eliminates the need for an oil bath lubrication system that permeates the cryogenic section. The architecture avoids having to manage oil containers during maintenance work. Only any tanker providing manual self-lubrication must be recharged during operation of certain elements of the appliance. The solution is compact and lightweight and can be applied to any type of piston pump, and any type of crank(s) drive mechanism.

Claims (13)

A device (1) for compressing cryogenic fluid, comprising:
a sealed enclosure (13) intended to contain a container (16) of cryogenic fluid;
Compression chambers (3, 4) in communication with the vessel;
an intake system (2) in communication with the compression chamber (3, 4), configured to enable introduction of fluid to be compressed into the compression chamber (3);
comprising a movable piston (5) to ensure compression of the fluid within the compression chambers (3, 4),
The device (1) further comprises an exhaust system (7) configured to communicate with the compression chamber (3, 4) and enable discharge of compressed fluid,
The piston 5 is mounted on the first end of the rod 50,
The device (1) comprises a mechanism (21) for driving the rod (50) with a back and forth movement in the longitudinal direction (A),
The drive mechanism 21 includes a motor 121 having a rotary shaft 211, and a second end of the rod 50 that rotates the rotary shaft 211 in the longitudinal direction A. It includes a mechanical system (212, 213) that translates into translational movement of the sliding head (8),
The head (8) is characterized in that it is slidably mounted and guided by two fixed guide rails (9) located on both sides of the head (8),
The head (8) and/or rail (9) comprises an elastic part (10), which exerts a transverse force in the longitudinal direction (A) on the rail or rails (9). It is characterized in that it is configured to generate,
Characterized in that the elastic part (10) comprises a spring or deformable zone and is subjected to prestress.
Device for compressing cryogenic fluid (1). According to paragraph 1,
Compression of the fluid in the compression chambers (3, 4) is achieved by traction or compression of the rod (50),
Characterized in that the traction or compression generates a transverse thrust of the head (8) on one of the rails (9) in a direction transverse to the longitudinal direction (A),
Device, characterized in that the acting force generated by the elastic part (10) is in the opposite direction to this thrust. According to paragraph 2,
The device, characterized in that the elastic part (10) is configured to generate in the rail or rails (9) a transverse force having an intensity, in absolute value, below the maximum intensity of the thrust force. According to any one of claims 1 to 3,
The device, characterized in that the elastic part (10) is located between the central region of the head (8) and one of the two rails (9). According to any one of claims 1 to 4,
The device, characterized in that the elastic part (10) is located between one of the two rails (9) and a fixed support of the rail. According to any one of claims 1 to 5,
Device, characterized in that in an operational configuration, the rod (50) is movable in a back-and-forth movement in the vertical longitudinal direction (A). According to any one of claims 1 to 6,
Device, characterized in that the mechanical system (212, 213), which converts the rotational movement of the rotating shaft (211) into the translational movement of the carriage (8), is of the connecting rod (213) and crank (212) type. According to any one of claims 1 to 7,
The mechanical system 212, 213, which converts the rotational movement of the rotary shaft 211 into a translational movement of the head 8, is connected to the central region of the head 8 via a ball joint or pivot connection 11. connected,
The connecting portion 11 is located on a longitudinal straight line A passing through the axis of translation of the rod 50,
The device, characterized in that the straight line further intersects the straight line passing through the rotating shaft (211) of the motor (210). According to any one of claims 1 to 8,
The head 8 is connected to the guide rail 9 via rolling element(s), for example a roller system, and/or a guide system with balls and/or sliding rollers, or a precision rail(s) type system. A device, characterized in that it is slidably mounted within. According to any one of claims 1 to 9,
A device characterized in that it is of the type with one compression stage, i.e. a type in which the fluid is compressed only once between the intake system (2) and the exhaust system (7). According to any one of claims 1 to 10,
A type with two compression stages, i.e. the fluid is compressed twice between the intake system (2) and the exhaust system (7),
The device (1) comprises two compression chambers (3, 4),
The intake system (2) communicates with the first compression chamber (3),
The transfer system (6) communicates with the first compression chamber (3) and the second compression chamber (4) and transfers the fluid compressed in the first compression chamber (3) to the second compression chamber (4). It is configured to enable transportation,
The movable piston (5) alternately compresses the fluid in the first compression chamber (3) and the second compression chamber (4) in its direction of movement,
The device, characterized in that the exhaust system (7) communicates with the second compression chamber (4). According to clause 11,
Characterized in that the second compression chamber (4) is defined by a part of the body of the piston (5) and a fixed wall of the device. A station for filling tanks or pipes with compressed gas, comprising:
source of liquefied gases, especially liquefied hydrogen (17);
a recovery 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 recovery circuit (18) comprises a compression device (1) according to any one of claims 1 to 12,
Station for filling tanks or pipes with compressed gas.