DE102022003732A1 - Pump for pumping cooled liquid gas from a first container to a second container - Google Patents

Abstract

The invention relates to a pump (1) for conveying cooled liquid gas from a first container to a second container, comprising: a conveying device (14) for conveying the liquid gas, wherein the conveying device (14) is accommodated in a first housing (8), wherein the first housing (8) is surrounded by a second housing (6) such that an insulation space (10) for thermally insulating the first housing is formed between the first housing (8) and the second housing (6).

Description

The invention relates to a pump for conveying cooled liquid gas from a first container to a second container according to the preamble of claim 1.

Liquid gas pumps are generally known from the state of the art.

For example, CN215333601U a low temperature feed pump head structure, the pump head having anti-cavitation structures comprising an impeller with a precursor.

The problem with the extraction of liquefied gas, especially liquid hydrogen, is that heat can be introduced during the extraction process, which can be particularly problematic when the liquefied gas is transferred from one container to another.

This heat input can lead to a change in the aggregate so that the liquid aggregate state to be pumped is converted into a gaseous state.

The object of the invention is therefore to provide a pump for conveying cooled liquefied gas, which allows the cooled liquefied gas to be conveyed from one container to a second container without changing its state of aggregation.

This object is achieved according to the invention with a pump having the features of claim 1.

According to one aspect of the invention, a pump is provided for conveying cooled liquid gas from a first container to a second container.

The pump has a conveying device for conveying the liquid gas, wherein the conveying device is accommodated in a first housing. The first housing is surrounded by a second housing such that an insulation space is formed between the first housing and the second housing for thermally insulating the first housing.

A cooled liquefied gas is any gas whose boiling point is below 30 K, in particular cooled liquid hydrogen, which has a boiling point of about 20 K at normal pressure.

The conveying device is also designed in such a way that a low heat input occurs. The conveying is preferably carried out via a radial pump that is designed for an axial inflow and a radial outflow, which overall allows for particularly low-energy conveying.

A conveying device is understood here to mean, in particular, a displacement device. The displacement device can have an external gear, particularly preferably an impeller with spiral blades with an impeller.

The conveying system is dimensioned in such a way that conveying quantities in the range of approximately 5 t/h to 500 t/h are excluded while introducing as little heat as possible, such as friction or conductive heat transfer.

By means of the pump according to the invention, it is also possible to convey larger quantities of liquid gas, in particular cooled hydrogen, from a first container to a second container without there being a significant change in the state of aggregation of the cooled liquid gas or the liquid cooled hydrogen.

This has the advantage that even larger quantities of cooled hydrogen can be pumped cost-effectively and safely from a first container to a second container.

The containers may, for example, be gas tanks that are arranged on ships and/or motor vehicles and that are to be transported from the mobile gas tank on the ship and/or motor vehicle to a stationary gas tank.

With the pump according to the invention it is possible to pump liquid gas, in particular liquid hydrogen, cost-effectively and safely from one gas tank to another gas tank and/or to gas tanks of corresponding consumer systems. The liquid gas, in particular the liquid hydrogen, can come from corresponding liquid gas production devices and/or hydrogen production devices which have previously produced the liquid gas/hydrogen and, if necessary, brought it into the liquid state.

According to one design of the pump, the isolation chamber can be evacuated so that a vacuum can be formed in the isolation chamber.

An isolation room that can be evacuated has the particular advantage that it can form a thermal barrier that can essentially prevent the relevant forms of heat input, so that the liquid gas remains in its pumped state, preferably liquid, even during the pumping process.

According to a further embodiment of the pump, the first and/or the second housing can be tempered with a coolant.

A coolant is understood here to mean a suitable cooling medium that can be conveyed to the appropriate positions of the first and second housings in order to release and/or absorb heat accordingly, so that a predetermined temperature can be maintained so that the liquid gas to be conveyed remains in its state of aggregation.

The coolant can also be a corresponding heating line, which tempers the corresponding housing accordingly so that the predetermined temperature in the pump can be maintained.

The cooling means can be designed either in separate and/or in the same devices on the pump, so that appropriate cooling or heating is possible.

According to a special design of the pump, a separate cooling element is arranged on the first and/or on the second housing. A separate cooling element is understood here to mean in particular a cooling device which has the coolant provided and/or regulates the temperature of the housing connected to it so that the predetermined temperature can be maintained.

A control or regulating circuit with suitable detection means can be provided for controlling and/or regulating temperature using the cooling element. The control or regulating circuit is designed to control/regulate the cooling element so that the predetermined temperature can be maintained.

The separate cooling element can be formed in an additional portion of the respective housing and/or formed in a third housing on the corresponding first or second housing.

According to a special embodiment of the pump, the insulation space has an evacuation connection which is formed on the second housing.

The evacuation connection makes it possible to create a vacuum in the insulation space. In addition, any condensate or leakage of liquid gas, for example from the first housing, can also be evacuated via the evacuation connection so that the insulation space does not accumulate unnecessary heat exchangers.

The evacuation port may be formed at any suitable position of the second housing that substantially defines the outer casing of the pump.

According to a further embodiment of the pump, the conveying device has a drive shaft and a drive unit, wherein the drive unit is spaced from the conveying device by a predetermined distance and can be flooded with the liquid gas.

The conveying device can be a displacement device, such as an external gear and/or an internal gear, which allows the liquid gas to be conveyed with as little energy as possible.

In particular, a paddle wheel with an inlet rotor is particularly advantageous here, so that the conveying device can be fed in the axial direction of rotation and conveyed radially to it, which allows the liquid gas to be conveyed with low energy.

In addition, the drive units and the conveyor system are spaced apart from each other so that heat transfer between the conveyor system and the drive unit is very low or impossible.

In addition, the area between the conveyor and the drive unit can be flooded with liquid gas so that this area can also be tempered accordingly.

According to a further design of the pump, the drive unit can be coupled to the drive shaft with a magnetic coupling.

This offers the advantage that the drive unit can be arranged in a separate housing or in a different component than the first and second housing, with the power transmission between the drive unit and the drive shaft taking place purely via the magnetic coupling. This also offers the advantage that the corresponding heat transfer through the drive unit itself and also through the drive work of the drive unit on the drive shaft is particularly low or can be completely prevented.

According to a further embodiment of the invention, the evacuation area of the isolation chamber is separated from the inner wall of the second housing and from the outer wall of the first Housing is defined and the inner wall and the outer wall are arranged at a predetermined distance from each other without contact.

This has the advantage that no thermal bridges occur, especially in the area of the housing to be insulated, which could cause additional undesirable heat to be introduced into the liquid gas.

According to a further embodiment of the pump, the first housing is kept at a distance from the second housing at a first inlet coupling flange for supplying the liquid gas to the conveying device, at a second outlet coupling flange for discharging the liquid gas conveyed by the conveying device and/or a through-opening projection for passing through a drive supply line.

The spaced mounting at predetermined locations limits the number of thermal bridges and heat input to the pump and reduces a change in the state of aggregation of the liquid gas to be pumped.

The drive supply line is in particular a power line through which electrical current can be supplied to the drive unit. Depending on the drive unit used, a suitable drive supply line can be used.

According to a further embodiment of the pump, the conveying device has an impeller with an impeller which is designed to avoid cavities on the impeller.

The induction rotor and the impeller can be arranged together in such a way that cavities can be avoided that lead to undesirable turbulence of the medium to be conveyed, which can in particular lead to a change in the state of aggregation of the medium to be conveyed.

The conveying device preferably has an impeller with blades that are surrounded by a support disk and cover disk. The impeller can also be assigned a front rotor with correspondingly wound blades. The blades of the impeller and the blades of the front rotor are designed for laminar conveying.

Both require cavity-free conveying, which in turn is advantageous for constant conveying of the liquid gas in the same state of aggregation.

According to a further design of the pump, the impeller has spiral-shaped blades, each of which is surrounded by a support disk and a cover disk.

According to a preferred embodiment of the pump, the drive unit of the impeller has an electric motor, wherein the rotor and/or the stator are in contact with the liquid gas.

The electric motor is designed in such a way that it can also be flooded with the cooled liquid gas.

This offers the advantage that the electric motor is also designed to be resistant and effective against the cooled liquid gas, so that a leak of liquid gas to the electric motor cannot have a negative effect on the pump performance. In addition, the electric motor is tempered accordingly, so that heat input via the electric motor can be avoided.

According to a further embodiment of the pump, a cooling chamber is provided for cooling the first housing and/or the second housing and/or the cooling chamber at least partially surrounds the first housing and/or the second housing.

This offers the advantage that appropriate cooling of the pump is possible even in environmental conditions that are not suitable for the pumping of liquefied gas.

For example, liquefied gas can also be extracted at very high temperatures in the warm seasons.

The pump according to the invention is explained in more detail below using some embodiments of the pump with reference to the accompanying figures.

• 1 eine Perspektivansicht der Pumpe zum Fördern von gekühltem Flüssiggas,
• 2 eine Teilschnittansicht der Pumpe aus 1 gemäß Schnittführung I-I aus 1.
• 3 eine Schnittansicht eines ersten Gehäuses der Pumpe aus 2 ohne die zugehörige Fördereinrichtung und Antriebseinheit, und
• 4 eine Teilschnittansicht der Fördereinrichtung aus 2 mit der zugehörigen Antriebseinheit.

They represent:

• 1 a perspective view of the pump for pumping cooled liquid gas,
• 2 a partial sectional view of the pump 1 according to section II from 1 .
• 3 a sectional view of a first housing of the pump 2 without the associated conveyor and drive unit, and
• 4 a partial sectional view of the conveyor system 2 with the associated drive unit.

1 shows in a perspective view the pump 1 according to the invention, which has a first outer housing 8 with an inlet coupling flange 2 and an outlet coupling flange 4. Furthermore, a through-opening for a through-opening projection 89 for a power supply of a drive unit 25 in a second housing 6 is formed on the first housing 8. The through-opening projection 89, together with the associated supply line, is sealed fluid-tight against the first housing 8 and the second housing 6.

The inlet coupling flange 2 and the outlet coupling flange 4 are designed for fluid-tight coupling with coupling flanges of associated hose lines.

All components of the pump 1 that are to come into contact with the liquid gas are preferably made of austenitic stainless steel such as V2A, V4A, aluminum and/or other metal alloys that are suitable for the transport of liquid gas, in particular liquid hydrogen.

The second housing 6 is arranged with its inner walls in the first housing 8 at a distance from the inner walls of the first housing 8, as can be seen from 2 so that an isolation space 10 is defined.

2 shows a partial sectional view of pump 1 from 1 according to section II from 1 .

As from 2 As can be seen, the pump 1 according to the invention has the second housing 6, which is also referred to below as the outer housing 6, and the first housing 8, which is also referred to below as the inner housing 8.

The outer housing 6 or the second housing 6 has a drive housing section 61 for accommodating a drive unit 24, an outlet housing channel section 62 which surrounds an outlet channel 82 of the inner housing 8, an outer housing channel cover 64 which adjoins a removable outer housing cover 63 and covers parts of the outer housing channel section 62, an outer housing pan section 65 and outer housing feed pipe section 66.

As from 2 As can be seen, the wall sections of the outer housing 6 are spaced at a predetermined distance from the respective wall sections of the inner housing 8, so that the insulation space 10 is defined.

The outer housing 6 is essentially formed in one piece, wherein in order to access the inner housing 8 and the associated elements accommodated therein, essentially only the outer cover 63 and the outer housing cover 64 are non-destructively connected to the remaining outer housing sections and can be dismantled for e.g. maintenance purposes.

The outer housing cover 63 can be connected to the outer housing pan section 65 by means of a screw connection via a corresponding groove that defines a sealing area 101. The sealing area 101 is designed to accommodate a continuous seal so that the static sealing surface is reduced. A flat seal made of metal, such as aluminum, and/or a sealing ring made of PTFE or PCTFE can be used as the seal.

The outer housing cover 63 can, for example, be glued and/or welded to the outlet housing channel section 62 in a fluid-tight manner. It is important here that the corresponding assembly and screw connections are sealed against one another in such a way that a vacuum can be formed in the insulation space 10 between the first housing 8 and the second housing 6, so that a corresponding thermal insulation of the area of the pump 1 that is flooded with the cooled liquid gas to be pumped is possible.

As further stated 2 As can be seen, the first housing 8 is arranged within the second housing 6 and also has the associated conveying device consisting of front rotor 16 and impeller 14.

The impeller 14 preferably has spiral-shaped blades 19 which are covered above and below the conveying channel defined by the blades by a support disk 17 and cover disk 19, as is also shown in 4 is shown.

A pre-runner 16 is arranged upstream of the impeller 14, which is intended to prevent the formation of cavities in the liquid gas to be pumped. The pre-runner 16 is preferably also provided with spiral-shaped blades, such as 4 can be removed.

The conveyor device 14 is connected to a drive unit 25 via a drive shaft 21.

In an embodiment not shown, the drive unit 25 is designed separately from the first housing 8 and the second housing 6 and can be coupled to the drive shaft 21 via a magnetic coupling for driving the drive shaft 21.

The drive unit 25 is preferably an electric motor. The drive unit 25 has a ring shaped stator 24 and a rod-shaped rotor 26 which is formed on the drive shaft 21.

The drive unit 25 is arranged at a distance from the conveyor device by means of a thermal spacer sleeve 22. The thermal spacer sleeve 22 can, however, also be designed such that the drive unit 25 is adjacent to and/or directly connected to the conveyor device 25.

A mounting flange 18 is formed between the conveyor device 14 and the drive unit 25 and the thermal spacer sleeve 22, by means of which the conveyor device 14 is held rotatably. The mounting flange 18 is arranged on the thermal spacer sleeve 22 by a mounting sleeve 20, as can be seen from 4 removable.

In 3 the first housing 1 or the inner housing 1 is shown, in which the drive unit 25 and the conveyor device 14 are accommodated.

The first housing 8 for accommodating the drive unit 25 and the conveyor device 14 has a cylindrical drive housing 81 for receiving the drive unit 25, a through-opening projection 89 for a wiring for the power supply of the drive unit 25, a mounting section flange 83, an impeller pan bottom 84, a circular conveyor channel 85, a removable impeller pan cover 86, a feed pipe section 87 and an impeller pan 800.

A sealing step 80 is formed between the impeller pan cover 86 and the mounting section of the conveying channel 85, which is formed on the peripheral section of the conveying channel. The sealing step 80 also defines a sealing region 100 which is formed continuously.

The sealing area 100 is designed to accommodate a continuous seal so that the static sealing surface is reduced. A flat seal made of metal, such as aluminum, and/or a sealing ring made of PTFE or PCTFE can be used as the seal.

Furthermore, recesses for fastening means 88 are formed in the sealing stage 80 and in the impeller pan cover 86 so that the impeller 14 can be accessed for maintenance purposes. The fastening means 88 can be screw connections, rivets and/or welded connections.

In the assembled state, the impeller pan cover 86 and the sections of the impeller pan bottom 84 and the conveying channel 85 of the first housing 8 form an impeller pan 800.

The conveying device 14 comprising the impeller 14 and the inlet rotor 16 is arranged in the impeller trough 800 so that liquid gas can be conveyed radially to a conveying channel 85. The liquid gas is fed axially to the conveying device 14 in the axial direction of the rotation axis A of the drive shaft 21 via the feed pipe section 87.

As further stated 3 As can be seen, the outlet pipe 82 has a circular channel cross-section that increases in the conveying flow direction 70 of the liquid gas, the circular conveying channel 85 having the largest diameter in the conveying direction 70 towards the outlet coupling flange 4. The channel cross-section is designed such that the liquid gas collected by the conveying device 14 can be conveyed to the outlet coupling flange in the conveying flow direction 70 towards the outlet coupling flange 4.

In the 3 In the embodiment shown, the drive housing 81 of the first housing 8 is attached to the impeller pan base 84 in a fluid-tight manner by means of a mounting flange 83. In an embodiment not shown here, the drive housing 81 can be formed in one piece with the impeller pan base 84.

In an embodiment not shown, a cooling chamber is provided for cooling the first housing 8 and/or the second housing 6. The cooling chamber can at least partially surround the first housing 8 and/or the second housing 6. Depending on the ambient conditions, the cooling chamber can be mounted on the pump and have its own cooling circuit. The cooling chamber is defined by a cooling device that provides and maintains a predetermined temperature electrically and/or by means of suitable fuels.

List of reference symbols

1

Pump for pumping gas in liquid state (liquid hydrogen)

2

Inlet coupling flange

4

Outlet coupling flange

6

Outer casing, second casing

8th

Inner casing, first casing

10

Isolation room

12

Evacuation connection

14

Conveyor/ impeller

15

Cover plate

16

Infeeder

17

Support disc

18

Mounting flange

19

shovel

20

Assembly sleeve

21

drive shaft

22

Thermal spacer sleeve

24

stator

25

Drive unit

26

rotor

61

Drive housing section

62

Outlet housing channel section

63

Outer housing cover

64

Outer casing duct cover

65

Outer casing pan section

66

Outer casing feed pipe section

70

Flow direction

80

Sealing level

81

Drive housing

82

Outlet pipe

83

Mounting section flange

84

Impeller tray bottom

85

Conveyor channel

86

Impeller pan cover

87

Feed pipe section

88

Fasteners

89

Through-opening approach

800

Impeller tray

100

Sealing area of the first housing

101

Sealing area of the second housing

A

Rotation axis

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• CN 215333601 U [0003]

Claims (13)

Pump (1) for conveying cooled liquid gas from a first container to a second container, comprising: a conveying device (14) for conveying the liquid gas, wherein the conveying device (14) is accommodated in a first housing (8), characterized in that the first housing (8) is surrounded by a second housing (6) such that an insulation space (10) for thermally insulating the first housing (8) is formed between the first housing (8) and the second housing (6). Pump after Claim 1 characterized in that the insulation space (10) can be evacuated so that a vacuum can be formed in the insulation space (10). Pump according to at least one of the Claims 1 or 2 characterized in that the first housing (8) and/or second housing (6) can be tempered with a coolant. Pump according to one of the preceding claims, characterized in that a separate cooling element is arranged on the first housing (8) and/or the second housing (6). Pump according to one of the preceding claims, characterized in that the insulation space (10) has an evacuation connection (12) which is formed on the second housing (6). Pump according to one of the preceding claims, characterized in that the conveying device (14) has a drive shaft (21) and a drive unit (25), wherein the drive unit is spaced from the conveying device by a predetermined distance and can be flooded with the liquid gas. Pump according to one of the preceding claims, characterized in that the drive unit (25) can be coupled to the drive shaft (21) by means of a magnetic coupling. Pump according to at least one of the preceding claims, characterized in that the evacuation region of the insulation space (10) is defined by the inner wall of the second housing (8) and by the outer wall of the first housing (6), and the inner wall and the outer wall are arranged at a predetermined distance from one another without contact. Pump according to one of the preceding claims, characterized in that the first housing (8) is held at a distance from the second housing (6) at a first inlet coupling flange (2) for supplying the liquid gas to the conveying device (14), at a second outlet coupling flange (4) for discharging the liquid gas conveyed by the conveying device (14) and/or a through-opening projection (89) for passing through a drive supply line. Pump according to one of the preceding claims, characterized in that the conveying device has an impeller (14) with an impeller (16) which is designed to avoid cavitation on the impeller (14). Pump according to one of the preceding claims, characterized in that the impeller (14) has spiral-shaped blades (19), each of which is surrounded by a support disk (17) and cover disk (15). Pump according to one of the preceding claims, characterized in that the drive unit (25) of the impeller (14) has an electric motor, wherein the rotor and/or the stator is/are in contact with the liquid gas. Pump according to one of the preceding claims, characterized in that a cooling chamber is provided for cooling the first housing (8) and/or the second housing (6), and/or the cooling chamber at least partially surrounds the first housing and/or the second housing.

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