System and method for producing liquefied natural gas

Patent metadata

Field	Value
Publication number	US-11460244-B2
Application number	US-201716308438-A
Country	US
Kind code	B2
Filing date	May 30, 2017
Priority date	Jun 30, 2016
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

A system and a method for producing liquefied natural gas are provided. The system includes a refrigeration loop system for providing a cold stream of refrigerant, a supersonic chiller for receiving and chilling a first gaseous natural gas stream to produce a liquefied natural gas liquid and separating the liquefied natural gas liquid from the first gaseous natural gas stream to obtain a second gaseous natural gas stream, and a cold box for receiving the cold stream of refrigerant and the second gaseous natural gas stream and cooling the second gaseous natural gas stream to obtain a liquefied natural gas by heat exchanging between the second gaseous natural gas stream and the cold stream of refrigerant.

First claim

What is claimed is:

1. A system for producing liquefied natural gas, the system comprising:
a refrigeration loop system for providing a cold stream of refrigerant;
a supersonic chiller for receiving and chilling a first gaseous natural gas stream, accelerating the first gaseous natural gas stream to a supersonic velocity and chilling the first accelerated gaseous natural gas stream to produce a liquefied natural gas liquid, and separating the liquefied natural gas liquid from the first gaseous natural gas stream to obtain a second gaseous natural gas stream;
a cold box for receiving the cold stream of refrigerant and the second gaseous natural gas stream from the supersonic chiller, and cooling the second gaseous natural gas stream to obtain a liquefied natural gas by heat exchanging between the second gaseous natural gas stream and the cold stream of refrigerant, whereon the cold box comprises a pre-cooling module for receiving and cooling a third gaseous natural gas stream to obtain the first gaseous natural gas stream, and providing the first gaseous natural gas stream to the supersonic chiller; and
a compressor downstream of the supersonic chiller and upstream of the cold box to increase the pressure of the second natural gas stream entering the cold box.

2. The system of claim 1 , wherein the temperature of the first gaseous natural gas stream ranges from 0° C. to −10° C.

3. The system of claim 1 , further comprising a compressor located upstream from the supersonic chiller.

4. The system of claim 1 , wherein the temperature of the liquefied natural gas liquid ranges from −45° C. to −75° C.

5. The system of claim 1 , wherein the pressure of the first gaseous natural gas stream ranges from 3 MPa to 8 MPa.

6. The system of claim 1 , wherein the refrigeration loop system comprises:
a compressing module for receiving and compressing a heat exchanged refrigerant stream to obtain a hot stream of refrigerant, and providing the hot stream of refrigerant to the cold box, wherein the cold box cools the hot stream of refrigerant to obtain a cooled refrigerant stream; and
an expanding module for receiving and expanding the cooled refrigerant stream to obtain the cold stream of refrigerant, and providing the cold stream of refrigerant to the cold box, wherein the cold box obtains the heat exchanged refrigerant stream by heat exchanging the cold stream of refrigerant with the second gaseous natural gas stream and the hot stream of refrigerant.

7. The system of claim 1 , wherein the refrigerant comprises nitrogen, methane, a mixed refrigerant or any combination thereof.

8. A method for producing liquefied natural gas, the method comprising:
providing, via a refrigeration loop system, a cold stream of refrigerant;
receiving and chilling, via a supersonic chiller, a first gaseous natural gas stream to produce a liquefied natural gas liquid, and separating the liquefied natural gas liquid from the first gaseous natural gas stream to obtain a second natural gas stream;
compressing the second natural gas stream exiting the supersonic chiller to increase the pressure of the second natural gas stream prior to entering a cold box;
receiving, via the cold box, the cold stream of refrigerant and the compressed second natural gas stream, and cooling the second gaseous natural gas stream to obtain a liquefied natural gas by heat exchanging between the second gaseous natural gas stream and the cold stream of refrigerant; and
receiving and cooling, via a pre-cooling module, a third gaseous natural gas stream to obtain the first gaseous natural gas stream, and providing the first gaseous natural gas stream to the supersonic chiller, the cold box comprising the pre-cooling module.

9. The method of claim 8 , further comprising: receiving a raw natural gas stream and separating an impurity from the raw natural gas stream to obtain the first gaseous natural gas stream, and providing the first gaseous natural gas stream to the supersonic chiller.

10. The method of claim 8 , further comprising: receiving a raw natural gas stream and separating an impurity from the raw natural gas stream to obtain the third gaseous natural gas stream, and providing the third gaseous natural gas stream to the pre-cooling module.

11. The system of claim 1 , further comprising a second compressor upstream of the supersonic chiller and configured to increase the pressure of the first gaseous natural gas stream before entering the supersonic chiller.

12. The system of claim 1 , further comprising an absorbent upstream of the supersonic chiller to remove acid gases from the first gaseous natural gas stream.

13. The method of claim 9 , further comprising removing acid gases from the raw natural gas stream to obtain the first gaseous natural gas stream before the first gaseous natural gas stream is received and chilled by the supersonic chiller.

14. The method of claim 13 , wherein the step of removing acid gases from the raw natural gas stream comprises contacting the raw natural gas stream with an absorbent.

Assignees

• Gen Electric
• Baker Hughes Oilfield Operations Llc

Inventors

• Hu Lishun
• Zhang Jie
• Acharya Harish Radhakrishna
• Xue Junli
• Lv Jing

Classifications

• F25J1/0052

  by vaporising a liquid refrigerant stream · CPC title

• F25J2230/30

  Compression of the feed stream · CPC title

• F25J2270/16

  with mutliple gas expansion loops of the same refrigerant · CPC title

• F25J1/0204

  as a single flow SCR cycle · CPC title

• F25J1/005 Primary

  by expansion of a gaseous refrigerant stream with extraction of work · CPC title