Cryogenic submersible pump system and cryogenic liquid storage

Abstract

The invention relates to a cryogenic submersible pump system for conveying and transferring a cryogenic liquid (8), as well as to a cryogenic liquid reservoir containing the submersible pump system. The cryogenic submersible pump system comprises a cryogenic piston pump (1) with an electrodynamic linear motor as a drive, which can be installed within a storage container (7) containing the cryogenic liquid (8) and can be operated immersed in the cryogenic liquid (8). The cryogenic submersible pump system and the cryogenic liquid reservoir are particularly suitable for conveying and transferring low-boiling cryogenic liquids (8), for example liquid hydrogen or liquid helium.

Description

[0001] The invention relates to a submersible pump system for conveying and transferring liquid cryogenic media, as well as a cryogenic liquid storage device containing the submersible pump system. The cryogenic submersible pump system and the cryogenic liquid storage device are particularly suitable for conveying and transferring low-boiling cryogenic liquids, for example, liquid hydrogen or liquid helium.

[0002] Low-boiling cryogenic liquids such as helium and hydrogen, which are liquefied using high energy, tend to evaporate during extraction and transfer even with a low energy input, for example through rapid rotor or piston movements or through slight pressure changes. After liquefaction, liquid helium is stored in large storage vessels at a slight overpressure, usually 100 mbar to 200 mbar, and at a slightly elevated temperature corresponding to the boiling point. From there, it is transferred to transportable storage vessels in which the liquid helium is stored at atmospheric pressure, i.e. without overpressure. The pressure drop during transfer causes the medium to evaporate, producing a large amount of evaporated helium (so-called flash gas), which then has to be re-liquefied at a high energy expenditure.In many other systems, a slight overpressure is often built up in the cryogenic source storage vessel compared to the cryogenic target vessel in order to transfer the liquefied cryogenic medium, although in these cases a large amount of flash gas is also generated.

[0003] One possible solution to circumvent the pressure drop is to store the liquefied cryogenic medium at atmospheric pressure without overpressure and transfer it using a pump. A pump should be selected that generates no or only minimal amounts of flash gas. This, considered across the entire value and supply chain, enables significant savings in the energy required to deliver the liquid cryogenic medium to the end user.

[0004] Since the basic intention is to keep the thermal connection from the pump to the warmer ambient area of ​​the storage tank to a minimum, i.e. to avoid massive components with high thermal conductivity, such as metallic piston rods, in the connection and transition areas, the use of pumps completely immersed in the cryogenic medium is the most common solution.

[0005] Here, it is possible to use so-called cryogenic centrifugal pumps, such as those commonly used for the transfer of liquefied natural gas (LNG). The use of centrifugal pumps for the conveying and transfer of cryogenic media leads to a high evaporation rate during the conveying process due to the high speed of the impellers, which introduce significant amounts of mechanical and consequently thermal energy into the cryogenic medium, particularly in the case of the low-boiling media helium and hydrogen. Furthermore, centrifugal pumps have the disadvantage that they always require a minimum suction pressure, i.e., they require a slight overpressure in the medium to be conveyed or subcooling of the medium to be conveyed, which in turn leads to the formation of flash gas.This makes the use of a centrifugal pump for low to moderate flow rates virtually obsolete, since the flow can also be achieved - without the use of a pump - by simply increasing the pressure in the cryogenic source storage vessel compared to the cryogenic target vessel.

[0006] As an alternative to centrifugal pumps, a piston pump for conveying cryogenic liquids is known from DE 10 2008 011 456 A1 and DE 10 2008 011 456 B4. It uses an electrodynamic linear motor as its drive. To ensure the functionality of the piston pump, correct installation in the storage tank is required; this can be particularly problematic in storage tanks with narrow openings.

[0007] From US 2015 / 0 276 130 A1 a system for a submersible pump is known, which comprises a cryogenic storage tank and a pump chamber, wherein the pump chamber is suspended in a vertical orientation on top of the cryogenic storage tank.

[0008] The pump chamber contains a liquid pump that can pump cryogenic liquid from the cryogenic storage tank.

[0009] The object of the invention is to provide a cryogenic submersible pump system with a piston pump driven by an electrodynamic linear motor, which enables the piston pump to be installed properly in a storage tank used to hold a cryogenic liquid as simply as possible. Furthermore, a cryogenic liquid storage tank with the cryogenic submersible pump system is to be provided as an overall system.

[0010] This object is achieved by a cryogenic submersible pump system having the features of claim 1 and a cryogenic liquid storage device according to claim 10 or 11. Advantageous developments of the invention are set forth in claims 2 to 9.

[0011] According to the invention, the cryogenic submersible pump system for installation in a storage container serving to hold a cryogenic liquid, i.e., a storage container for the cryogenic liquid, comprises a cryogenic piston pump with an electrodynamic linear motor as the drive. The piston pump has a cylinder housing and a freely oscillating piston mounted in the cylinder housing so as to be displaceable along the cylinder's longitudinal direction.

[0012] The piston pump itself is preferably designed according to DE 10 2008 011 456 A1 and DE 10 2008 011 456 B4.

[0013] The piston is designed to incorporate at least one permanent magnet and at least one drive coil into the cylinder wall, with the axis of the drive coil and the dipole axes of the permanent magnet running parallel. The piston is mounted in the cylinder housing so that it can move parallel to the coil axis. The piston is moved back and forth exclusively by an alternating magnetic field generated by the drive coil. The resulting drive is a linear motor in the so-called "moving magnet" design.

[0014] Alternatively, a linear motor in the so-called “moving coil design” can be used as a drive, in which the magnetic field-generating drive coil is integrated in the piston and the magnet(s) are integrated in the cylinder wall.

[0015] In one embodiment of the cryogenic piston pump invention, a double-acting pump characterized by particularly high efficiency, adjacent to both end faces of the piston are pumping chambers whose volumes are alternately increased and decreased by the movement of the piston. Each pumping chamber has an inlet and an outlet. A check valve is located in both the inlet and outlet, allowing the cryogenic liquid to flow in the direction of flow and blocking flows against the direction of flow. Consequently, when the volume of the pumping chambers increases, the cryogenic liquid is drawn in through the inlet; when the volume decreases, the liquid is forced out of the pumping chamber and into the outlet. The double-acting piston pump has a symmetrical design with respect to the center position of the piston in the cylinder housing.

[0016] Alternatively, the cryogenic piston pump can also be designed as a single-acting pump, with a pumping chamber adjacent to only one end of the piston. The pumping process is analogous to that of a double-acting pump, but with only one pumping chamber. However, the design of such a piston pump is more complex. The drive motor must act on a load with asymmetric force characteristics. The oscillator center position becomes load-dependent and must be electronically adjusted. The pumping power is halved, the efficiency remains the same, and the flow pattern becomes discontinuous.

[0017] According to the invention, the described cryogenic piston pump is designed as a tube-like unit extending along the cylinder's longitudinal direction, which is dimensioned such that the cryogenic piston pump can be inserted into the storage container in at least one orientation through a container opening serving for filling or removing the cryogenic liquid. This means that the cryogenic piston pump only needs to fit through the container opening in one orientation, for example, through the passage of a container opening designed as a neck tube.

[0018] In some embodiments, the cryogenic submersible pump system comprises an inlet line connected to the cryogenic piston pump, namely at each inlet of the cryogenic piston pump, for sucking the cryogenic liquid from the storage vessel, and an outlet line connected to the cryogenic piston pump, namely at each outlet of the cryogenic piston pump, for conveying the cryogenic liquid from the storage vessel. The inlet line, if designed in this way, has at least one intake nozzle immersed in the cryogenic liquid. According to the invention, the outlet line has a variably bendable outlet line section. The variably bendable outlet line section can be designed as a flexibly deformable line, for example, as a so-called flexible line, or as a pipe swivel joint.

[0019] Furthermore, according to one embodiment, the cryogenic submersible pump system comprises an electronic control and regulation unit attached to the cryogenic piston pump for controlling and regulating the cryogenic piston pump and at least one power supply line for supplying the cryogenic piston pump and the control and regulation unit with electrical energy.

[0020] According to the invention, the submersible pump system also has a feedthrough element that can be installed in the tank opening of the storage tank and serves to pass the energy supply line through the tank opening of the storage tank.

[0021] According to the invention, the cryogenic submersible pump system is designed such that only the outlet line and the feedthrough element with the energy supply line are led out of the storage tank.

[0022] Finally, the cryogenic submersible pump system includes an installation cable for suspending and supporting the cryogenic piston pump during its insertion into or removal from the storage vessel. The installation cable is attached to a suitable suspension point on the cryogenic piston pump. The installation cable can remain within the storage vessel after the cryogenic piston pump has been installed, for example, to permanently support the cryogenic piston pump; however, the installation cable can also be removed completely.Preferably, the suspension point for the installation cable is located at one of the axial end regions of the cryogenic piston pump, so that the cryogenic piston pump, suspended freely from the installation cable, is aligned approximately perpendicular to the cylinder's longitudinal direction; the outlet line leading to the feedthrough element, with the variably angled outlet line section, branches off, if possible, at the opposite axial end region of the cryogenic piston pump.

[0023] The cryogenic submersible pump system enables rapid installation of the cryogenic piston pump in the storage vessel, even with a small vessel opening, i.e., with spatially limited access, such as with a liquid helium canister with a narrow neck tube. In its preferred embodiment, the cryogenic piston pump is a double-acting pump with a symmetrical design and the shortest possible intake port, preferably installed horizontally within the storage vessel with respect to its cylinder length. The cryogenic submersible pump system allows the cryogenic piston pump to be inserted into the storage vessel with a narrow vessel opening, aligned lengthwise to the vessel opening, and to be brought into its functional position within the storage vessel. The installation cable and, if necessary, the outlet line can be used for positioning within the storage vessel.

[0024] The cryogenic submersible pump system is designed specifically for the pumping and transfer of cryogenic liquids down to a temperature of 4 K, i.e., in addition to liquid nitrogen, oxygen, argon, neon, methane or natural gas, also for the pumping of liquid hydrogen or liquid helium.

[0025] The cryogenic submersible pump system avoids the problems associated with centrifugal pumps. The proposed piston pump, which requires no minimum suction pressure compared to centrifugal pumps, introduces only small amounts of mechanical and thus thermal energy into the cryogenic fluid due to its slow piston movement. Likewise, the reduced connections to the warmer ambient area ensure the transfer of thermal energy into the cryogenic fluid. The cryogenic submersible pump system thus enables the transfer of the cryogenic fluid between two containers at the same pressure level without significant flash gas formation.

[0026] According to the invention, the cryogenic liquid storage device comprises, in addition to the described cryogenic submersible pump system, the storage vessel and the cryogenic liquid contained in the storage vessel. After installation in the storage vessel, the cryogenic piston pump, which can be installed in the storage vessel, is submerged in the cryogenic liquid, at least with the intake port(s) of the inlet line and, in one embodiment, the control and regulation unit attached to the cryogenic piston pump. The control and regulation unit can, in principle, also be installed at room temperature. Placing the control and regulation unit in the cryogenic liquid improves efficiency due to the sharp decrease in the specific resistance of electrical conductor materials in the cryogenic temperature range.

[0027] The cryogenic piston pump can feature unslotted piston seals for sealing between the cylinder housing and the piston. The piston seals can be either unreinforced or spring-reinforced.

[0028] The cryogenic piston pump can further be designed such that a specific axial parking position is provided for the piston along the cylinder's longitudinal axis, which the piston assumes during the cooling process. When using piston seals, the axial parking position of the piston sealed against the cylinder housing by the piston seals is, for example, a position of the piston in the cylinder housing where there is no contact between the piston seals and the cylinder housing. This prevents the piston seals from mechanically deforming during the cooling process.

[0029] Furthermore, it can be provided that at least one intake port of the inlet line of the cryogenic piston pump has a suction valve which is controlled passively by springs or actively by the control and regulation unit.

[0030] The power supply line and / or the electrodynamic linear motor, in particular the drive coil of the piston pump, can be constructed from conventional conductor material, for example copper, or from a superconducting conductor material, for example a material based on bismuth-strontium-calcium-copper oxide, yttrium-barium-copper oxide or niobium-titanium.

[0031] According to the invention, the cryogenic submersible pump system comprises a holding and tilting mechanism for holding the cryogenic piston pump in the storage vessel and for changing the pump orientation when installing the cryogenic piston pump in the storage vessel. The holding and tilting mechanism comprises the installation cable and a tilting rod. The installation cable is pivotally attached to one axial end of the cryogenic piston pump, while the tilting rod is pivotally attached to the other axial end of the cryogenic piston pump. The installation cable, together with the tilting rod, is pivotally attached to a suspension point on the feedthrough element. The feedthrough element, in turn, can be connected to an attachment in the area of ​​the vessel opening of the storage vessel. The installation cable and the tilting rod form a triangular suspension for the cryogenic piston pump.The installation cable is attached to the suspension point on the feedthrough element in an adjustable length, so that by operating the installation cable, i.e., by pulling or releasing, the installation cable section within the triangular suspension can be enlarged or reduced. The holding and tilting mechanism enables the cryogenic piston pump to be folded in and out relative to the outlet line by operating the installation cable; the holding and tilting mechanism is therefore also referred to as a folding / unfolding mechanism. The variably angled outlet line section is preferably arranged on the side of the end region of the cryogenic piston pump connected to the tilt rod. During folding and unfolding, the variably angled outlet line section enables the rigid sections of the outlet line to be adjusted.After installation of the cryogenic piston pump in the storage tank, the triangular suspension also serves to permanently and contact-free mount the cryogenic piston pump in the storage tank.

[0032] As already described, the variably deflectable outlet line section can be designed as a flexibly deformable line or as a swivel joint, which in this case also includes designs such as rotary unions or swivel joint scissors. Since flexibly deformable lines can only be bent up to a minimum permissible bending radius, this design requires a minimum volume in the storage tank. If, however, space is limited in the storage tank, the variably deflectable outlet line section can be designed as a swivel joint.

[0033] The pipe swivel joint (also called a pipeline swivel joint) preferably comprises two hollow screw connectors that can be rotated relative to each other in a scissor-like manner. These connectors are connected by a screw connection and sealed by a movable seal. The movable seal is located between the two hollow screw connectors; the hollow screw connectors are joined, for example, by means of a screw sealed on both sides. Two rigid pipe sections of the outlet line are connected to the pipe swivel joint, so that the outlet line is designed to be flexible, media-tight, and capable of conveying fluids in the variably angled outlet line section thanks to the pipe swivel joint.

[0034] Furthermore, the cryogenic submersible pump system or the cryogenic liquid storage tank can be provided with a pump adapter that is geometrically adapted to the bottom of the storage tank and detachably connectable to the cryogenic piston pump. The pump adapter can, for example, be anchored to a recess in the tank bottom, conform to the tank bottom due to gravity, or be permanently installed by the storage tank manufacturer. During installation, the cryogenic piston pump is lowered through the tank opening of the storage tank while suspended from the installation cable, i.e., usually in a vertical position. The pump adapter is then locked to a suitable coupling point in the storage tank using the pump adapter.

[0035] The invention is explained in more detail below using exemplary embodiments and with reference to the schematic drawings, wherein identical or similar features are provided with the same reference numerals; in this case: Fig. 1: a version of the cryogenic submersible pump system in side view with partial perspective view, Fig. 2: the cryogenic liquid storage tank with the cryogenic submersible pump system in sectional view and partial side view, Fig. 3: the cryogenic piston pump in longitudinal section, Fig. 4: a first installation variant with pump adapter in sectional view, Fig. 5: a second installation variant with pump adapter in sectional view, and Fig. 6: a third installation variant with pump adapter in sectional view.

[0036] The cryogenic submersible pump system according to Fig. 1 comprises the cryogenic piston pump 1, designed as a double-acting pump, at whose two axial end areas the intake ports 2.1 of the inlet line 2 are attached. These each have a suction valve with spring-supported control. The outlet line 3 is attached to both sides of the cryogenic piston pump 1 in the form of partial lines; the two partial lines of the outlet line 3 are joined before the variably angled outlet line section. The variably angled outlet line section forms the Fig. 1 shows the flexibly deformable pipe in the form of the flexible pipe 3.1. As an alternative to the flexible pipe 3.1, the variably angled outlet pipe section can be realized using the pipe swivel joint 3.2.

[0037] The installation cable 4 and the tilt rod 5 form a triangular suspension for the cryogenic piston pump 1. By operating the installation cable 4, the cryogenic piston pump 1 can be folded in or out during installation. The feedthrough element 6, at the lower end of which the installation cable 4 and the tilt rod 5 are attached, exclusively carries the power supply line (not shown).

[0038] Fig. 2 illustrates that according to Fig. 1 formed cryogenic submersible pump system after introduction into the storage vessel 7. The cryogenic piston pump 1 is completely immersed in the cryogenic liquid 8, so that the cryogenic liquid 8 can be sucked in for transfer via the inlet line 2 and pumped out of the storage vessel 7 via the outlet line 3. The cryogenic piston pump 1 is used for introduction or removal - as under Fig. 1 - folded in so that it can be passed vertically hanging through the container opening 7.1 in the area of ​​the neck pipe of the storage container 7.

[0039] The cryogenic piston pump 1 - see Fig. 3 - basically has the design known from the prior art according to DE 10 2008 011 456 A1 or DE 10 2008 011 456 B4, shown here as a double-acting pump. It comprises the cylinder housing 11, in which the piston 10 is mounted so as to be movable in the longitudinal direction of the cylinder. Several permanent magnets 10.1 are embedded in the piston 10 with a precise fit and without any protrusion, with the dipole axes of all permanent magnets 10.1 running parallel to the longitudinal direction of the cylinder. The cylinder housing 11 is constructed in one piece; its inner sides form the cylinder liners. The outer side of the cylinder housing 11 serves as a carrier for the drive coil 11.1. For this purpose, a circumferential recess is provided in the outer side, in which the drive coil 11.1 is located.

[0040] A cylinder head cover 16 is located on each end face of the cylinder housing 11. The piston 10, together with the cylinder liner and the respective cylinder head cover 16, encloses a pumping chamber 12. A pumping chamber opening 13 is located in each cylinder head cover 16, which serves for the inflow and outflow of the cryogenic liquid 8 to be pumped.

[0041] On the cylinder head cover 16 there is the inlet line 2 with an inlet check valve 14 switched in the direction of flow and the outlet line 3 with an outlet check valve 15 switched in the direction of flow.

[0042] The Fig. 4 to 6 illustrate different variants for installing the cryogenic piston pump 1 into the storage vessel 7 using the pump mounting adapter 9. The cryogenic piston pump 1 is lowered vertically through the vessel opening 7.1 of the storage vessel 7 from above using the installation cable 4 and locked to a suitable coupling point in the storage vessel 7 with the aid of the pump mounting adapter 9. If necessary, the installation cable 4 can be removed from the vessel after the cryogenic piston pump 1 has been laid down or locked into place, if the cryogenic piston pump 1 is to remain permanently in the storage vessel 7.

[0043] Many storage containers 7 do not have a flat container bottom; for example, in conventional, portable 1000-liter liquid helium cans, there is a curved elevation 7.2 in the center of the container bottom. Fig. 4, this curved elevation 7.2 on the bottom of the storage tank 7 is used as a locking point for tilting and positioning the cryogenic piston pump 1 or the pump mounting adapter 9.

[0044] Another, in Fig. The embodiment shown in Figure 5 is to adapt the external shape of the cryogenic piston pump 1 to the container bottom of the storage container 7 by means of the pump mounting adapter 9. For example, the pump mounting adapter 9 can correspond to the curvature of the container bottom, so that the cryogenic piston pump 1, after being lowered to the container bottom of the storage container 7, can position itself by gravity with the aid of the pump mounting adapter 9.

[0045] Furthermore, as in Fig.6 - the pump mounting adapter 9 adapted to the cryogenic piston pump 1, in particular its pump contour, must be pre-assembled by the manufacturer in the storage container 7, for example in the form of a half-shell which serves to fix the cryogenic piston pump 1. List of reference symbols 1 piston pump 2 Inlet line 2.1 Intake manifold 3 Outlet line 3.1 Flexible cable 3.2 Pipe swivel joint 4 Installation rope 5 tilt rod 6 Feedthrough element 7 storage tanks 7.1 Container opening 7.2 arched elevation 8 cryogenic liquid 9 pump adapter 10 pistons 10.1 Permanent magnet 11 Cylinder housing 11.1 Drive coil 12 Pump chamber 13 Pump chamber opening 14 Inlet check valve 15 Outlet check valve 16 cylinder head covers

Claims

[1] Cryogenic submersible pump system for installation in a storage tank (7) for holding a cryogenic liquid (8) which has a tank opening (7.1) for filling or removing the cryogenic liquid (8), the cryogenic submersible pump system comprising: - a cryogenic piston pump (1) with an electrodynamic linear motor as a drive, wherein the cryogenic piston pump (1) comprises a cylinder housing (11) and a freely oscillating piston (10) mounted in the cylinder housing (11) so as to be displaceable along a cylinder longitudinal direction, and wherein the cryogenic piston pump (1) is designed as a tube-like unit extending along the cylinder longitudinal direction, which is dimensioned such that the cryogenic piston pump (1) can be inserted into the storage container (7) at least in one orientation through the container opening (7.1), - at least one power supply line for supplying the cryogenic piston pump (1) with electrical energy, - an outlet line (3) connected to the cryogenic piston pump (1) for conveying the cryogenic liquid (8) from the storage container (7), and - an inlet line (2) connected to the cryogenic piston pump (1) for sucking the cryogenic liquid (8) from the storage container (7), wherein - the outlet line (3) has a variably angled outlet line section, - the inlet line (2) has at least one intake nozzle (2.1) immersed in the cryogenic liquid (8), - the cryogenic submersible pump system has a feedthrough element (6) which can be installed in the container opening (7.1) of the storage container (7) for passing through the energy supply line, wherein the cryogenic submersible pump system is designed such that only the outlet line (3) and the feedthrough element (6) with the energy supply line are led out of the storage container (7), - the cryogenic submersible pump system comprises an installation rope (4) for suspending and holding the cryogenic piston pump (1) when it is introduced into or removed from the storage tank (7), and - the cryogenic submersible pump system has a holding and tilting mechanism for holding the cryogenic piston pump (1) in the storage tank (7) and for changing the pump orientation when installing the cryogenic piston pump (1) in the storage tank (7), wherein the holding and tilting mechanism comprises the installation cable (4) and a tilting rod (5), and wherein the installation cable (4) is articulated to one axial end region of the cryogenic piston pump (1), the tilting rod (5) is articulated to the other axial end region of the cryogenic piston pump (1), and the installation cable (4) together with the tilting rod (5) are articulated to a suspension point on the feedthrough element (6), so that the installation cable (4) and the tilting rod (5) form a triangular suspension of the cryogenic piston pump (1), wherein the installation cable (4) is attached to the suspension point on the feedthrough element (6) in such a way that its length can be varied,that by operating the installation rope (4) an installation rope section within the triangular suspension can be enlarged or reduced., [2] Cryogenic submersible pump system according to claim 1, characterized by that the cryogenic piston pump (1) further comprises an electronic control and regulation unit attached to the cryogenic piston pump (1) for controlling and regulating the cryogenic piston pump (1). [3] Cryogenic submersible pump system according to claim 2, characterized by that the cryogenic piston pump (1) has unslotted piston seals for sealing between the cylinder housing (11) and the piston (10). [4] Cryogenic submersible pump system according to claim 3, characterized bythat the cryogenic piston pump (1) is designed such that the piston (10), which is sealed against the cylinder housing (11) by means of piston seals, has at least one axial parking position along the cylinder longitudinal direction, at which there is no contact between the piston seals and the cylinder housing (11). [5] Cryogenic submersible pump system according to one of claims 1 to 4, characterized by that the power supply line and / or the electrodynamic linear motor comprises a superconducting conductor material. [6] Cryogenic submersible pump system according to one of claims 1 to 5, characterized by that the variably angled outlet line section is arranged on the side of the axial end region of the cryogenic piston pump (1) connected to the tilting rod (5). [7] Cryogenic submersible pump system according to one of claims 1 to 6, characterized by that the variably angled outlet line section is a flexibly deformable line. [8] Cryogenic submersible pump system according to one of claims 1 to 7, characterized by that the variably angled outlet line section has a pipe swivel joint (3.2), wherein the pipe swivel joint (3.2) has two hollow screw sockets which can be rotated against each other in a scissor-like manner and which are connected by means of a screw connection and sealed by means of a movable seal. [9] Cryogenic submersible pump system according to one of claims 1 to 8, characterized by that it further comprises a pump receiving adapter (9) which is geometrically adapted to a container bottom of the storage container (7) and which can be detachably connected to the cryogenic piston pump (1). [10] Cryogenic liquid storage device with a cryogenic submersible pump system according to one of claims 1 to 9, wherein the cryogenic liquid storage device further comprises, in addition to the cryogenic submersible pump system, the storage container (7) and the cryogenic liquid (8) accommodated in the storage container (7), wherein the cryogenic piston pump (1) which can be installed in the storage container (7) is submerged in the cryogenic liquid (8) after installation in the storage container (7) at least with the intake nozzle(s) (2.1) of the inlet line (2). [11] Cryogenic liquid storage device with a cryogenic submersible pump system according to one of claims 2 to 9, wherein the cryogenic submersible pump system has the control and regulation unit according to claim 2, and wherein the cryogenic liquid storage device, in addition to the cryogenic submersible pump system, further comprises the storage container (7) and the cryogenic liquid (8) accommodated in the storage container (7), wherein the cryogenic piston pump (1) which can be installed in the storage container (7) is submerged in the cryogenic liquid (8) after installation in the storage container (7) at least with the intake nozzle(s) (2.1) of the inlet line (2) and the control and regulation unit attached to the cryogenic piston pump (1).

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