# US 9,752,728 B2 · Cryogenic tank assembly

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- Number: US 9,752,728 B2
- Document ID: US9752728B2
- Status: Granted
- Kind: B2
- Application number: 13/722,502
- Filed: 2012-12-20
- Published: 2014-06-26
- Granted: 2017-09-05
- Earliest claimed: 2012-12-20
- Assignees: General Electric Company
- Applicants: General Electric Company
- Inventors: Ching-Jen Tang; Laura Michele Hudy
- Web page: https://patentgrep.com/patent/US9752728B2

## CPC

- F17C 7/04: with change of state, e.g. vaporisation
- B64D 37/30: Fuel systems for specific fuels
- F17C 2201/0104: cylindrical
- F17C 2201/0128: spherical or elliptical
- F17C 2201/054: medium (>1 m3)
- F17C 2203/03: Thermal insulations
- F17C 2203/032: Multi-sheet layers
- F17C 2203/0325: Aerogel
- F17C 2203/0604: Liners
- F17C 2203/0626: Multiple walls
- F17C 2203/0629: Two walls
- F17C 2205/0119: Vessel walls form part of another structure
- F17C 2205/0326: electrically actuated
- F17C 2205/0329: manually actuated
- F17C 2205/0332: Safety valves or pressure relief valves
- F17C 2205/0338: Pressure regulators
- F17C 2205/035: Flow reducers
- F17C 2205/0397: on both sides of the pressure vessel
- F17C 2221/033: Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
- F17C 2223/0161: cryogenic, e.g. LNG, GNL, PLNG
- F17C 2223/0169: subcooled
- F17C 2223/033: Small pressure, e.g. for liquefied gas
- F17C 2225/0123: gaseous, e.g. CNG, GNC
- F17C 2227/0107: by pressurising the ullage
- F17C 2227/0135: Pumps
- F17C 2227/0178: in the vessel
- F17C 2227/0185: comprising several pumps or compressors
- F17C 2227/0302: by heating
- F17C 2227/0381: integrated in the wall
- F17C 2227/039: on the pipes
- F17C 2227/0397: characterised by fins
- F17C 2250/01: Intermediate tanks
- F17C 2250/032: using computers
- F17C 2265/066: for feeding engines for propulsion
- F17C 2270/0189: Planes
- F17C 2270/07: for household use
- F17C: VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES (storing fluids in natural or artificial cavities or chambers in the earth B65G5/00; construction or assembling of bulk storage containers employing civil-engineering techniques E04H7/00; variable-capacity gas-holders F17B; liquefaction or refrigeration machines, plants, or systems F25)
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT

## Abstract

A cryogenic tank assembly includes a cryogenic tank having an internal volume that is configured to contain liquefied natural gas (LNG). The cryogenic tank includes an inlet and an outlet that are each fluidly connected to the internal volume. The assembly includes a recirculation conduit coupled in fluid communication between the inlet and the outlet. The recirculation conduit extends along a path between the inlet and outlet external to the internal volume of the cryogenic tank such that the path is configured to be exposed to an ambient environment of the cryogenic tank. The recirculation conduit is configured to: receive a flow of LNG from the internal volume through the outlet; transfer heat from the ambient environment to the LNG flow to change the LNG flow to a flow of natural gas; and inject the natural gas flow into the internal volume of the cryogenic tank through the inlet.

## Claims

### Claim 1

A cryogenic tank assembly comprising:
a cryogenic tank having an internal volume, the cryogenic tank being configured to contain liquefied natural gas (LNG) within the internal volume, the cryogenic tank comprising a first inlet fluidly connected to the internal volume and a first outlet fluidly connected to the internal volume;
a recirculation conduit coupled in fluid communication between the first inlet and the first outlet of the cryogenic tank such that the recirculation conduit fluidly connects the first inlet to the corresponding first outlet, the recirculation conduit extending along a path between the first inlet and a corresponding first outlet external to the internal volume of the cryogenic tank such that the path of the recirculation conduit is configured to be exposed to an ambient environment of the cryogenic tank,
wherein the recirculation conduit comprises a second inlet that is fluidly connected to the first outlet and a second outlet that is fluidly connected to the corresponding first inlet, and
further wherein the recirculation conduit is configured to:
receive a flow of LNG from the internal volume through the first outlet into the second inlet,
transfer heat from the ambient environment of the cryogenic tank to the LNG flow to change the LNG flow to a flow of vaporous natural gas, and
inject the vaporous natural gas flow into the internal volume of the cryogenic tank through the first inlet and the second outlet,
wherein the second inlet comprises at least one first flow control component to control a reception of the flow of LNG and the second outlet comprises at least one second flow control component to control an injection of the flow of vaporous natural gas,
wherein the recirculation conduit further comprises:
a first recirculation conduit that extends along a corresponding path that is a first path, the cryogenic tank comprising a wall that extends a thickness between an internal side and an external side, the external side being configured to be directly exposed to the ambient environment of the cryogenic tank, the first path extending within the thickness of the wall, and
a second recirculation conduit that extends along a second corresponding path between the first inlet and the first outlet, the second path extending external to the external side such that at least a segment of the second path is configured to extend within the ambient environment of the cryogenic tank in a spaced apart relationship with the external side; and
a controller operatively connected to the first recirculation conduit and to the second recirculation conduit such that the controller is configured to control at least one of: the at least one first flow control component, and the at least one second flow control component and thereby regulate a pressure within the internal volume of the cryogenic tank by controlling at least one of: an amount of the natural gas; or a pressure of the natural gas that is injected into the internal volume of the cryogenic tank from the first recirculation conduit and the second recirculation conduit.

### Claim 2 (depends on 1)

The assembly of claim 1, wherein the thickness of the wall comprises a thermal insulation, the first path of the first recirculation conduit extending through the thermal insulation of the wall of the cryogenic tank.

### Claim 3 (depends on 1)

The assembly of claim 1, wherein the first recirculation conduit comprises a coil that extends around the internal volume within the thickness of the wall such that the first path of the first recirculation conduit comprises a spiral shape.

### Claim 4 (depends on 1)

The assembly of claim 1, wherein the first path of the recirculation conduit is configured to be indirectly exposed to the ambient environment through a thermal insulation of the cryogenic tank.

### Claim 5 (depends on 1)

The assembly of claim 1, further comprising a heat exchanger coupled in fluid communication with second the recirculation conduit along the second path of the second recirculation conduit, the heat exchanger being configured to transfer heat from the ambient environment to the LNG flow within the second recirculation conduit.

### Claim 6 (depends on 1)

The assembly of claim 1, further comprising an auxiliary tank coupled in fluid communication with the second recirculation conduit along the second path of the second recirculation conduit, the auxiliary tank being configured to contain at least a portion of the LNG flow, the auxiliary tank being configured to transfer heat from the ambient environment to LNG contained therein.

### Claim 7 (depends on 1)

The assembly of claim 1, further comprising an auxiliary tank coupled in fluid communication with the second recirculation conduit along the second path of the second recirculation conduit, the auxiliary tank being configured to contain at least a portion of the LNG flow within an internal chamber of the auxiliary tank, the auxiliary tank comprising a solid absorbent within the internal chamber.

### Claim 8 (depends on 1)

The assembly of claim 1, wherein the controller is operatively connected to a pump, the controller being configured to regulate an amount of heat absorbed by the LNG flow within the recirculation conduit by controlling a flow rate of the LNG flow using the pump.

### Claim 9 (depends on 1)

The assembly of claim 1, wherein the at least one first flow control component comprises at least one of: at least one valve, at least one nozzle, at least one restrictor, at least one venturi, at least one check valve, at least one sensor, at least one manual shutoff, and at least one automatic shutoff.

### Claim 10 (depends on 1)

The assembly of claim 1, wherein the at least one second flow control component comprises at least one of: at least one valve, at least one nozzle, at least one restrictor, at least one venturi, at least one check valve, at least one sensor, at least one manual shutoff, and at least one automatic shutoff.