Accumulator with internal heat exchanger

• US 20020083733A1
• Filed: 12/29/2000
• Published: 07/04/2002
• Est. Priority Date: 12/29/2000
• Status: Active Grant

• Current Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Urdea, Teodor, Zhang, Chao A., Mehraban, Henry, Gibbons, Richard G. Jr.
• Granted Patent: US 6,523,365 B2
• Time in Patent Office: Days
• US Class Current: 62/503
• CPC Class Codes: F25B 2309/06 Compression machines, plants or systems characterised by the refrigerant being carbon dioxide
• CPC Class Codes: F25B 2400/051 between the accumulator and another part of the cycle
• CPC Class Codes: F25B 40/00 Subcoolers, desuperheaters or superheaters
• CPC Class Codes: F25B 43/006 Accumulators
• CPC Class Codes: F25B 9/008 the refrigerant being carbon dioxide
• CPC Class Codes: F28D 7/0033 the conduits for one medium or the conduits for both media being bent
• CPC Class Codes: F28D 7/04 the conduits being spirally coiled F28D7/10 takes precedenceF28D7/0016 and F28D7/0033 take precedence
• CPC Class Codes: F28D 7/14 both tubes being bent
• CPC Class Codes: F28F 2260/02 having microchannels

Abstract

An accumulator with an internal heat exchanger for use in an air conditioning or refrigeration system having a compressor, a condenser, an expansion device, and an evaporator is disclosed. In operation, the accumulator is placed in the system so high pressure, high temperature refrigerant flowing from the condenser and low pressure, low temperature refrigerant flowing from the evaporator simultaneously enter and flow through the heat exchanger disposed in the accumulator whereby the low pressure, low temperature refrigerant absorbs heat and thereby cools the high pressure, high temperature refrigerant. In one embodiment, the heat exchanger comprises a tube having at least one high temperature channel and one low temperature channel extending through the interior of the tube. In a second embodiment, the heat exchanger comprises a single spirally wound coaxial tube having an outer tube and an inner tube positioned within the outer tube. In a third embodiment, the heat exchanger comprises a plurality of coaxial tubes, each coaxial tube having an outer tube and an inner tube positioned in the outer tube wherein the inner tubes are fluidly connected.

Claims

1. An accumulator for an air conditioning or refrigeration system comprising:

a housing, said housing comprising an upper portion and a lower portion joined together to form a chamber;

a high pressure inlet port for conveying a high pressure refrigerant from a condenser into the accumulator;

a high pressure outlet port for discharging the high pressure refrigerant from the accumulator to an evaporator;

a low pressure inlet port for conveying low pressure refrigerant from an evaporator into the accumulator;

a low pressure outlet port for discharging the low pressure refrigerant from the accumulator to a compressor; and

a vapor conduit tube for conveying the low pressure refrigerant in the accumulator to a heat exchanger disposed in the chamber, said heat exchanger comprising at least one tube having an interior, a internal end, an external end, at least one low temperature channel, and at least one high temperature channel, each channel extending through the interior of the tube, wherein the external end of the high temperature channel is connected to the high pressure inlet port, the external end of the low temperature channel is connected to the low pressure outlet port, the internal end of the low temperature channel is connected to the vapor conduit tube, and the internal end of the high temperature channel is connected to the high pressure outlet port.

2. The accumulator of claim 1 wherein the housing is cylindrical.

3. The accumulator of claim 1 wherein the heat exchanger is spirally wound and the internal end is located interiorly in the spiral.

4. The accumulator of claim 1 further comprising a deflector positioned within said housing.

5. The accumulator of claim 4 wherein the deflector is dome shaped.

6. The heat exchanger of claim 1 wherein said high temperature and said low temperature channels comprise adjacent rows of microchannels.

7. The heat exchanger of claim 1 wherein the refrigerant flows through the low temperature channel in a direction opposite the flow of refrigerant through the high temperature channel.

8. An accumulator for an air conditioning or refrigeration system comprising:

a hollow housing having a top and a bottom joined together to form a closed chamber; and

a heat exchanger disposed in the housing, said heat exchanger comprising at least one tube defining at least one high temperature channel therethrough, and at least one low temperature channel therethrough, wherein a refrigerant discharged from a condenser enters the accumulator and flows through the high temperature channel before being discharged to an evaporator, and a refrigerant discharged from the evaporator enters the accumulator and flows through the low temperature channel in a heat exchange relationship with refrigerant flowing through the high temperature channel before being discharged to a compressor.

9. The accumulator of claim 8 wherein the refrigerant flowing through the high temperature channel flows in the opposite direction of the refrigerant flowing through the low temperature channel.

10. The accumulator of claim 8 further comprising a deflector positioned in said housing.

11. The heat exchanger of claim 8 wherein the said high temperature and said low temperature channels comprise adjacent rows of microchannels.

13. The method of claim 12 wherein the low temperature and high temperature channels comprise a plurality of microchannels.

15. The accumulator of claim 14 wherein the heat exchanger is spirally shaped.

16. The accumulator of claim 14 further comprising a deflector positioned within said housing.

19. The method of claim 18 wherein the heat exchanger is helically shaped.

20. The method of claim 18 wherein the accumulator further comprises a deflector positioned within said accumulator.

12. A method of operating an air conditioning or refrigeration cycle comprising:

conveying condensed refrigerant into an accumulator having an internal heat exchanger, said heat exchanger comprising at least one tube defining at least one high temperature channel therethrough and at least one low temperature channel therethrough,

conveying the condensed refrigerant through the high temperature channel of the heat exchanger;

discharging refrigerant from the high temperature channel and accumulator;

evaporating the refrigerant;

conveying the evaporated refrigerant through a vapor conduit tube positioned in the accumulator and into the low temperature channel to flow in a heat exchange relationship with refrigerant flowing through the high temperature channel;

discharging the evaporated refrigerant from the low temperature channel and accumulator; and

conveying the discharged evaporated refrigerant to a compressor.

14. An accumulator for an air conditioning or refrigeration system comprising:

a hollow housing having a top and a bottom;

a low pressure inlet port extending through a first opening defined in the top for conveying a refrigerant from an evaporator into the housing;

a low pressure outlet port extending through a second opening defined in the top for discharging refrigerant from a heat exchanger positioned in the housing to a compressor;

a high pressure inlet port extending through a third opening defined in the top for conveying refrigerant from a condenser to the heat exchanger;

a high pressure outlet port extending through a fourth opening in the top for discharging refrigerant from the heat exchanger to an evaporator; and

a vapor conduit tube having first and second ends for conveying refrigerant in the accumulator housing to the heat exchanger, said heat exchanger comprising an outer tube having a first outer tube end and a second outer tube end, and an inner tube positioned within the outer tube having a first inner tube end and a second inner tube end, wherein the high pressure inlet port is attached at the first inner tube end, the high pressure outlet tube is attached at the second inner tube end, the first vapor conduit end is attached at the first outer tube end and the low pressure outlet port is attached at the second outer tube end.

17. An accumulator for an air conditioning or refrigeration system comprising:

a hollow housing having a top and a bottom;

a heat exchanger disposed in the housing, said heat exchanger comprising a helical coaxial tube having an outer tube and an inner tube disposed within the outer tube, wherein a refrigerant from a condenser flows into the accumulator and through the inner tube and simultaneously a refrigerant from an evaporator flows into the accumulator and through the outer tube in a heat exchange relationship.

18. A method of operating an air conditioning or refrigeration system comprising:

conveying condensed refrigerant through a high pressure inlet port into an accumulator having an internal heat exchanger, said heat exchanger comprising an outer tube having a first outer tube end and a second outer tube end, and an inner tube positioned within the outer tube having a first inner tube end and a second inner tube end wherein the high pressure inlet port is attached at the first inner tube end, a high pressure outlet tube is attached at the second inner tube end, a vapor conduit tube is attached at the first outer tube end, and a low pressure outlet port is attached at the second outer tube end;

conveying the condensed refrigerant through the inner tube of the heat exchanger;

discharging the condensed refrigerant from the inner tube of the heat exchanger and accumulator through the high pressure outlet port;

evaporating the refrigerant;

conveying the evaporated refrigerant into the accumulator through the low pressure inlet port;

conveying the evaporated refrigerant through the vapor conduit tube and into the outer tube in a heat exchange relationship with the refrigerant flowing through the inner tube;

discharging the evaporated refrigerant from outer tube and accumulator through the low pressure outlet port; and

conveying the evaporated refrigerant to a compressor.

21. An accumulator for an air conditioning or refrigeration system comprising:

a top, an upper shell, a plate, a lower shell, and a bottom, wherein said top, upper shell, plate, lower shell and bottom form a closed housing having an upper chamber and a lower chamber separated by the plate;

a low pressure inlet port extending into the upper chamber;

a vapor conduit tube extending through the top, into the upper chamber, through an opening in the plate, and into the lower chamber;

heat exchanger comprising a plurality of coaxial tubes at least partially within said housing, each coaxial tube further comprising an outer tube and an inner tube disposed within the outer tube, said inner tube extending through the top, into the upper chamber, through the plate, into the lower chamber and through the bottom, said outer tube extending through the upper chamber, through the plate, and into the lower chamber.

22. The accumulator of claim 21 wherein the low pressure inlet port extends through an opening in the top or an opening in the upper shell into the upper chamber.

23. The accumulator of claim 21 wherein a high temperature refrigerant flows through the inner tubes and a low temperature refrigerant flows through the outer tubes in a heat exchange relationship.

24. The accumulator of claim 21 wherein the inner tubes are serially connected.

25. The accumulator of claim 21 wherein the inner tubes are connected in parallel.

26. The accumulator of claim 21 wherein the heat exchanger comprises a first, second, third, and fourth coaxial tube, each coaxial tube having a first, second, third, and fourth outer tube, a first, second, third, and fourth inner tube, each inner tube having an upper inner tube end and a lower inner tube end, wherein the first upper inner tube end is connected to the second upper inner tube end, the second lower inner tube end is connected to the third lower inner tube end, and the third upper inner tube end is connected to the fourth upper inner tube end.

27. The accumulator of claim 26 wherein a high temperature refrigerant enters the first lower inner tube end, flows through the four inner tubes, and exits the fourth lower inner tube end and a low temperature refrigerant flows through the four outer tubes in a heat exchange relationship with the high temperature refrigerant flowing through the inner tubes.

28. An accumulator for an air conditioning system or a refrigeration system comprising:

a housing, a top, and a bottom, said housing, top and bottom forming a closed chamber;

and a heat exchanger disposed in the chamber comprising a plurality of coaxial tubes, each coaxial tube having an outer tube enclosed in the housing and an inner tube extending through the top, chamber and bottom, wherein said inner tubes are fluidly connected to allow a high temperature refrigerant to flow therethrouh while a low temperature refrigerant simultaneously flows through the outer tubes in a heat exchange relationship.

29. A method of operating an air conditioning or refrigeration system comprising:

conveying condensed refrigerant through a high pressure inlet port into an accumulator having an internal heat exchanger, said heat exchanger comprising a plurality of coaxial tubes, each coaxial tube further comprising an outer tube and an inner tube disposed within the outer tube, wherein said inner tubes extend through the accumulator and are fluidly connected;

conveying the condensed refrigerant through the inner tubes;

discharging the condensed refrigerant from the inner tubes and accumulator through a high pressure outlet port;

evaporating the refrigerant;

conveying the evaporated refrigerant into the accumulator through a low pressure inlet port;

conveying the evaporated refrigerant in the accumulator through the outer tubes of the heat exchanger in a heat exchange relationship with the condensed refrigerant flowing through the inner tubes;

conveying the evaporated refrigerant into a vapor conduit tube;

discharging the evaporated refrigerant from the vapor conduit tube and accumulator; and

conveying the evaporated refrigerant to a compressor.

30. A method of cooling a high temperature liquid refrigerant in an air conditioning or refrigeration system comprising:

conveying the high temperature refrigerant through a heat exchanger disposed in an accumulator while simultaneously conveying a low temperature refrigerant through the heat exchanger, said heat exchanger comprising at least one tube defining at least one high temperature channel therethrough, and at least one low temperature channel therethrough, wherein the high temperature refrigerant flows through the high temperature channel in a heat exchange relationship with low temperature refrigerant flowing through the low temperature channel.

31. A method for cooling a high temperature refrigerant discharged from a condenser in an air conditioning or refrigeration system comprising:

conveying the high temperature refrigerant through a heat exchanger disposed in an accumulator while simultaneously conveying a low temperature refrigerant through the heat exchanger, said heat exchanger comprising a helically shaped coaxial tube having an outer tube and an inner tube disposed within said outer tube, wherein the high temperature refrigerant flows through the outer tube and the low temperature refrigerant flows through the inner tube in a heat exchange relationship.

32. A method of cooling a high temperature refrigerant in an air conditioning or refrigeration system comprising:

conveying the high temperature refrigerant through a heat exchanger while simultaneously conveying a low temperature refrigerant through the heat exchanger, the heat exchanger comprising a plurality of coaxial tubes, each coaxial tube further comprising an outer tube disposed entirely within the accumulator and an inner tube positioned in the outer tube, said inner tube extending through the accumulator, wherein the high temperature refrigerant flows through the inner tubes and the low temperature refrigerant flows through the outer tubes.