Air conditioner and method of controlling the same

Patent metadata

Field	Value
Publication number	US-9746210-B2
Application number	US-201514825935-A
Country	US
Kind code	B2
Filing date	Aug 13, 2015
Priority date	Aug 14, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

An air conditioner and a method of controlling the same are provided. The air conditioner includes first and second compressors capable of performing multi-stage compression, a condenser for condensing a refrigerant compressed in the first and second compressors, a refrigerant separation device for separating the refrigerant to be injected to the first or second compressor of the refrigerant condensed in the condenser, injection tubes extending from the refrigerant separation device to the first and second compressors to guide injection of the refrigerant, a main expansion device disposed at an outlet-side of the refrigerant separation device to decompress the refrigerant, an evaporator for evaporating the refrigerant decompressed in the main expansion device, a valve device disposed at an outlet-side of the first compressor to guide the refrigerant compressed in the first compressor to the condenser or the second compressor, and a bypass tube extending from the valve device to an suction-side of the second compressor.

First claim

What is claimed is:

1. An air conditioner comprising:
first and second compressors for compressing a refrigerant that is injected into the first and second compressors, wherein the compressing comprises multi-stage compression;
a condenser for condensing the refrigerant compressed in the first and second compressors;
a refrigerant separation device for separating the refrigerant before the refrigerant is injected into the first and second compressors;
injection tubes extending from the refrigerant separation device to the first and second compressors to guide the injection of the refrigerant;
a main expansion device disposed at an outlet-side of the refrigerant separation device for decompressing the refrigerant condensed in the condenser;
an evaporator for evaporating the refrigerant decompressed in the main expansion device;
a valve device disposed at an outlet-side of the first compressor for guiding the refrigerant compressed in the first compressor to the condenser or to the second compressor; and
a bypass tube extending from the valve device to a suction-side of the second compressor,
wherein the valve device comprises:
an inlet into which the refrigerant compressed in the first compressor is introduced;
a first outlet from which the refrigerant compressed in the first compressor and introduced into the inlet is discharged to a valve connection tube that is connected to an inlet-side of the condenser; and
a second outlet from which the refrigerant compressed in the first compressor is discharged to the bypass tube.

2. The air conditioner according to claim 1 , further comprising:
a compressor branch part for dividing the refrigerant evaporated in the evaporator and allowing the divided refrigerants to flow to the first and second compressors;
a first suction tube extending from the compressor branch part to the first compressor; and
a second suction tube extending from the compressor branch part to the second compressor.

3. The air conditioner according to claim 2 , wherein the bypass tube extends from the second outlet of the valve device to the second suction tube.

4. The air conditioner according to claim 2 , wherein the valve connection tube is connected to the first outlet of the valve device, and further comprising:
a discharge tube for discharging the refrigerant compressed in the second compressor; and
a combination part at which the valve connection tube is combined with the discharge tube.

5. The air conditioner according to claim 1 , wherein a branch refrigerant that is heat-exchanged in the refrigerant separation device is divided to flow in the injection tubes, and
a refrigerant in one of the injection tubes is injected into the first compressor, and a refrigerant in the another one of the injection tubes is injected into the second compressor.

6. The air conditioner according to claim 5 , wherein the refrigerant separation device comprises:
a first supercooling heat exchanger in which the refrigerant condensed in the condenser is heat-exchanged with a first branch refrigerant divided from the refrigerant condensed in the condenser; and
a second supercooling heat exchanger in which the refrigerant that is heat-exchanged in the first supercooling heat exchanger is heat-exchanged with a second branch refrigerant divided from the refrigerant that is heat-exchanged in the first supercooling heat exchanger.

7. The air conditioner according to claim 6 , wherein the injection tubes comprise a first injection tube and a second injection tube through which the first branch refrigerant that is heat-exchanged in the first supercooling heat exchanger is divided to flow into,
wherein the refrigerant in the first injection tube is injected into the first compressor, and
wherein the refrigerant in the second injection tube is injected into the second compressor.

8. The air conditioner according to claim 7 , wherein the injection tubes further comprise a third injection tube and a fourth injection tube through which the second branch refrigerant that is heat-exchanged in the second supercooling heat exchanger is divided to flow into,
wherein the refrigerant in the third injection tube is injected into the first compressor, and
wherein the refrigerant in the fourth injection tube is injected into the second compressor.

9. The air conditioner according to claim 8 , further comprising:
a first injection expansion device disposed on the first injection tube to decompress the refrigerant in the first injection tube; and
a second injection expansion device disposed on the third injection tube to decompress the refrigerant in the third injection tube.

10. The air conditioner according to claim 9 , wherein the refrigerant decompressed in the first injection expansion device is injected into a high pressure-side of the first compressor, and
the refrigerant decompressed in the second injection expansion device is injected into a low pressure-side of the first compressor.

11. The air conditioner according to claim 8 , wherein the refrigerant in the second injection tube is injected into a high pressure-side of the second compressor, and
the refrigerant in the fourth injection tube is injected into a low pressure-side of the second compressor.

12. The air conditioner according to claim 1 , wherein the valve device operates in a first operation mode such that the refrigerant compressed in the first compressor is mixed with the refrigerant compressed in the second compressor, and
wherein the valve device operates in a second operation mode such that the refrigerant compressed in the first compressor is suctioned into the second compressor via the bypass tube.

13. The air conditioner according to claim 1 , wherein the refrigerant separation device comprises a phase separator.

14. The air conditioner according to claim 1 , further comprising a check valve disposed at a suction-side of the second compressor to restrict the refrigerant from the suction-side of the second compressor from flowing to a compressor branch part.

15. A method of controlling an air conditioner comprising a first compressor, a second compressor, a condenser, a main expansion device, and an evaporator, the method comprising:
driving the first and second compressors;
determining an action mode of a valve device disposed at an outlet-side of the first compressor according to an operation mode;
dividing the refrigerant passing through the condenser by opening a first supercooling expansion device to allow the refrigerant to be heat-exchanged in a first supercooling heat exchanger and to flow through a first injection tube; and
dividing the refrigerant passing through the first supercooling heat exchanger by opening a second supercooling expansion device to allow the refrigerant to be heat-exchanged in a second supercooling heat exchanger and to flow through a third injection tube,
wherein, when a first operation mode of the operation mode is performed, each of the first and second compressors performs a three-stage compression with respect to the refrigerant, and
when a second operation mode is performed, the refrigerant successively passes through the first and second compressors and is compressed in five stages.

16. The method according to claim 15 , wherein the action mode of the valve device comprises:
a first action mode in which the refrigerant compressed in the first compressor is discharged to an inlet-side of the condenser when the first operation mode is performed; and
a second action mode in which the refrigerant compressed in the first compressor is discharged to a suction-s

Assignees

• Lg Electronics Inc

Inventors

• Ko Younghwan
• Kim Byeongsu
• Kim Beomchan

Classifications

• F25B43/00

  Arrangements for separating or purifying gases or liquids (in analysers or rectifiers F25B33/00); Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat (F25B40/00 takes precedence) · CPC title

• F25B2400/13

  Economisers · CPC title

• F25B2400/075

  with parallel compressors · CPC title

• F25B2600/2509

  Economiser valves · CPC title

• F25B2400/0401

  for compressors · CPC title