Device and method for refrigerating or liquefying a fluid

Patent metadata

Field	Value
Publication number	US-12455113-B2
Application number	US-202218276828-A
Country	US
Kind code	B2
Filing date	Jan 18, 2022
Priority date	Feb 10, 2021
Publication date	Oct 28, 2025
Grant date	Oct 28, 2025

Abstract

Disclosed is a device for refrigerating or liquefying a fluid such as natural gas or hydrogen, comprising a fluid circuit that is to be cooled and has an upstream end for connection to a source of gaseous fluid as well as a downstream end for connection to a member for collecting the cooled or liquefied fluid, the device comprising a heat exchanger assembly in heat exchange with the fluid circuit to be cooled, the device comprising a refrigerator in heat exchange with at least a portion of the exchanger assembly, the refrigerator being of the type that has a cycle for refrigerating a cycle gas containing at least one of: helium, hydrogen, nitrogen or neon; said refrigerator comprising in series in a cycle circuit: a mechanism for compressing the cycle gas, at least one member for cooling the cycle gas, a mechanism for expanding the cycle gas, and at least one member for reheating the expanded cycle gas, wherein the compression mechanism comprises a plurality of compression stages in series composed of a centrifugal compressor assembly, the compression stages being mounted on a set of shafts that are rotationally driven by a motor assembly, the at least one member for cooling the cycle gas comprising at least one heat exchanger at the outlet of at least one compression stage in heat exchange with the cycle circuit, said heat exchanger being cooled by a heat transfer fluid, characterized in that the compression mechanism comprises at least two compression stages that are arranged successively in series and do not include any member for cooling the cycle gas such as a heat exchanger therebetween.

First claim

The invention claimed is:

1. A device for refrigeration or liquefaction of a fluid, the device comprising:
a circuit for fluid that is to be cooled, having an upstream end intended to be connected to a source of gaseous fluid and a downstream end intended to be connected to a member for collecting the cooled or liquefied fluid;
an assembly of heat exchanger(s) in a heat exchange relationship with the circuit for fluid that is to be cooled;
a refrigerator in a heat exchange relationship with at least part of the assembly of heat exchanger(s), the refrigerator configured to perform a refrigeration cycle on a cycle gas, the cycle gas selected from the group consisting of: helium, hydrogen, nitrogen, neon, and combinations thereof,
said refrigerator comprising the following, disposed in series in a cycle circuit:
a compression mechanism configured to compress the cycle gas,
at least one cooling member configured to cool the cycle gas,
an expanding mechanism configured to expand the cycle gas, and
at least one heating member configured to heat the expanded cycle gas,

wherein the compression mechanism comprises multiple compression stages in series that are composed of an assembly of compressor(s) of centrifugal type,
wherein the compression stages are mounted on a set of shafts driven in rotation by an assembly of motor(s),
wherein the at least one cooling member comprises at least one heat exchanger disposed at the outlet of at least one compression stage in a heat exchange relationship with the cycle circuit,
wherein said heat exchanger is cooled by a heat transfer fluid,
wherein the compression mechanism comprises at least two compression stages that are disposed successively in series and do not have a member for cooling the cycle gas such as a heat exchanger for exchanging heat between them,
wherein the assembly of motor(s) comprises multiple motors for driving the compression stages,
wherein at least one of the motors is cooled by a flow of cycle gas via at least one bypass pipe for a fraction of the flow of cycle gas supplying the compression mechanism, and
wherein the bypass pipe comprises an upstream end attached to the outlet of at least one of the compression stages for drawing off a fraction of the flow of cycle gas.

2. The device as claimed in claim 1 , wherein the fluid is selected from the group consisting of natural gas and hydrogen.

3. The device as claimed in claim 1 , wherein the compression mechanism comprises four compression stages in series, the member for cooling the cycle gas comprising three cooling heat exchangers that are disposed respectively at the outlet of three of these four compression stages, for example between the first and the second compression stage, between the second and the third compression stage, and at the outlet of the fourth compression stage.

4. The device as claimed in claim 1 , further comprising cooling heat exchangers disposed solely every two compression stages in series.

5. The device as claimed in claim 1 , wherein the assembly of motor(s) comprises a separate respective motor for each compression stage.

6. The device as claimed in claim 1 , wherein a downstream end of at least one bypass pipe is attached to the inlet of a compression stage after it passes and exchanges heat with at least one motor.

7. The device as claimed in claim 6 , wherein the at least one bypass pipe comprises, between its upstream end and its downstream end, a subdivision into at least two separate branches respectively supplying separate motors in order to cool them.

8. The device as claimed in claim 7 , wherein the at least two separate branches formed by the subdivision of a bypass pipe have a downstream junction within one and the same pipe portion.

9. The device as claimed in claim 1 , wherein the at least one bypass pipe comprises at least one member for cooling the cycle gas.

10. The device as claimed in claim 9 , wherein the at least one member for cooling the cycle gas of the at least one bypass pipe comprises a cooling heat exchanger.

11. A method for refrigeration or liquefaction of a fluid using a refrigeration device as claimed in claim 1 , wherein said method includes the steps of: circulating a fluid in the circuit for fluid that is to be cooled; and cooling said fluid via the cold produced by the refrigerator.

12. The method as claimed in claim 11 , further comprising the step of controlling the rotational speed of the compression stages in accordance with independent speeds, wherein, during at least one determined operating phase, the rotational speed of the compression stages in series that do not have a member for cooling the cycle gas such as a heat exchanger for exchanging heat between them is kept at a speed lower than the rotational speed of the compression stages that are provided at their outlet with a member for cooling the cycle gas.

13. The method as claimed in claim 11 , wherein the fluid is selected from the group consisting of natural gas and hydrogen.

Assignees

• Air Liquide

Inventors

• Roig Mathieu
• Nicolas Remi
• Durand Fabien
• Delautre Guillaume

Classifications

• F25J1/0289

  Use of different types of prime drivers of at least two refrigerant compressors in a cascade refrigeration system · CPC title

• F25J1/0235

  Heat exchange integration · CPC title

• F25B31/026

  with compressor of rotary type · CPC title

• F25B25/005

  using primary and secondary systems · CPC title

• F25B9/10

  with several cooling stages · CPC title