Hybrid vapor compression-absorption cycle

• US 20070019708A1
• Filed: 05/16/2006
• Published: 01/25/2007
• Est. Priority Date: 05/18/2005
• Status: Active Grant

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Yokozeki, Akimichi, Shiflett, Mark
• Granted Patent: US 7,765,823 B2
• Time in Patent Office: Days
• US Class Current: 374/181
• CPC Class Codes: C09K 5/047 for absorption-type refrigeration systems
• CPC Class Codes: F25B 25/02 Compression-sorption machines, plants, or systems

Abstract

The present invention relates to a hybrid vapor compression-absorption cooling or heating system and apparatus containing a refrigerant pair comprising at least one refrigerant and at least one ionic liquid. The present invention also provides for the performance of a hybrid vapor compression-absorption cycle that utilizes refrigerants and absorbents such as fluorocarbon gases in fluorinated ionic liquids. The present invention also provides a method of cooling by the execution of a hybrid vapor compression-absorption cycle using a refrigerant pair comprising at least one refrigerant and at least one ionic liquid. The present invention also provides a method of heating by the execution of a hybrid vapor compression-absorption cycle using a refrigerant pair comprising at least one refrigerant and at least one ionic liquid.

Claims

1. An apparatus for temperature adjustment comprising

(a) an absorber that forms a mixture of a mixture of a refrigerant and an absorbent;

(b) a generator that receives the mixture from the absorber and heats the mixture to separate refrigerant, in vapor form, from the absorbent, and increases the pressure of the refrigerant vapor;

(c) a condenser that receives the vapor from the generator and condenses the vapor under pressure to a liquid;

(d) a pressure reduction device through which the liquid refrigerant leaving the condenser passes to reduce the pressure of the liquid to form a mixture of liquid and vapor refrigerant;

(e) an evaporator that receives the mixture of liquid and vapor refrigerant that passes through the pressure reduction device to evaporate the remaining liquid to form first and second portions of refrigerant vapor;

(f) a compressor that receives the first portion of the refrigerant vapor, increases the pressure thereof, and passes the first portion of the refrigerant vapor to the condenser; and

(g) a conduit that passes the second portion of the refrigerant vapor leaving the evaporator to the absorber.

3. An apparatus according to claim 1 wherein the condenser is located in proximity to an object, medium or space to be heated.

5. An apparatus according to claim 1 wherein the evaporator is located in proximity to an object, medium or space to be cooled.

7. An apparatus according to claim 1 or 2 wherein the refrigerant is selected from one or more members of the group consisting of a hydrofluorocarbon, a hydrochlorofluorocarbon, a chlorofluorocarbon, a fluorocarbon, N₂, O₂, CO₂, NH₃, Ar, H₂, H₂O, and a non-fluorinated hydrocarbon, wherein the non-fluorinated hydrocarbon is selected from the group consisting of C₁ to C₄ straight-chain, branched or cyclic alkanes and C₁ to C₄ straight-chain, branched or cyclic alkenes.

8. An apparatus according to claim 7 wherein a hydrofluorocarbon is selected from the group consisting of:

difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), and fluoroethane (HFC-161).

9. An apparatus according to claim 7 wherein a hydrochlorofluorocarbon is chlorodifluoromethane (HCFC-22).

10. An apparatus according to claim 7 wherein a chlorofluorocarbon is dichlorodifluoromethane (CFC-12).

11. An apparatus according to claim 7 wherein a fluorocarbon is selected from the group consisting of perfluoromethane (FC-14) and perfluoroethane (FC-116).

12. An apparatus according to claim 7 wherein a non-fluorinated hydrocarbon is selected from the group consisting of methane, ethane, ethylene, propane, cyclopropane, propene, propylene, butane, butene, and isobutane.

13. An apparatus according to claim 7 wherein a refrigerant is selected from the group consisting of HFC-32, HFC-125, HFC-134, HFC-134a, HFC-143a, HFC-152a, HFC-161, HCFC-22, FC-14, FC-116, CFC-12.

14. An apparatus according to claim 1 or 2 wherein the absorbent comprises one or more ionic liquids.

15. An apparatus according to claim 7 wherein the absorbent comprises one or more ionic liquids.

16. An apparatus according to claim 14 wherein an ionic liquid comprises a cation selected from the group consisting of:

wherein R¹, R², R³, R⁴, R⁵ and R⁶ are each independently selected from the group consisting of;

(i) H;

(ii) halogen;

(iii) —

CH₃, —

C₂H₅, or C₃ to C₂₅ straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH₂ and SH;

(iv) —

CH₃, —

C₂H₅, or C₃ to C₂₅ straight-chain, branched or cyclic alkane or alkene comprising one to three heteroatoms selected from the group consisting of O, N, Si and S, and optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH₂ and SH;

(v) C₆ to C₂₀ unsubstituted aryl, or C₃ to C₂₅ unsubstituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N, Si and S; and

(vi) C₆ to C₂₅ substituted aryl, or C₃ to C₂₅ substituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N, Si and S;

wherein said substituted aryl or substituted heteroaryl has one to three substituents independently selected from the group consisting of;

1. —

CH₃, —

C₂H₅, or C₃ to C₂₅ straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F I, OH, NH₂ and SH,

2. OH,

3. NH₂, and

4. SH; and

wherein R⁷, R⁸, R⁹, and R¹⁰ are each independently selected from the group consisting of;

(vii) —

CH₃, —

C₂H₅, or C₃ to C₂₅ straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH₂ and SH;

(viii) —

CH₃, —

C₂H₅, or C₃ to C₂₅ straight-chain, branched or cyclic alkane or alkene comprising one to three heteroatoms selected from the group consisting of O, N, Si and S, and optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH₂ and SH;

(ix) C₆ to C₂₅ unsubstituted aryl, or C₃ to C₂₅ unsubstituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N, Si and S; and

(x) C₆ to C₂₅ substituted aryl, or C₃ to C₂₅ substituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N, Si and S;

wherein said substituted aryl or substituted heteroaryl has one to three substituents independently selected from the group consisting of;

(1) —

CH₃, —

C₂H₅, or C₃ to C₂₅ straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH₂ and SH,

(2) OH,

(3) NH₂, and

(4) SH; and

wherein optionally at least two of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ can together form a cyclic or bicyclic alkanyl or alkenyl group.

17. An apparatus according to claim 16 wherein any one of, or any group of more than one of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ comprises F−

.

18. An apparatus according to claim 14 wherein an ionic liquid comprises an anion selected from the group consisting of [CH₃CO₂]⁻

, [HSO₄]⁻

, [CH₃OSO₃]⁻

, [C₂H₅OSO₃]⁻

, [AlCl₄]⁻

, [CO₃]²⁻

, [HCO₃]⁻

, [NO₂]⁻

, [NO₃]⁻

, [SO₄]²⁻

, [PO₄]³⁻

, [HPO₄]²⁻

, [H₂PO₄]⁻

, [HSO₃]⁻

, [CuCl₂]⁻

, Cl⁻

, Br⁻

, I⁻

, SCN⁻

and any fluorinated anion.

19. An apparatus according to claim 18 wherein a fluorinated anion is selected from the group consisting of [BF₄]⁻

, [PF₆]⁻

, [SbF₆]⁻

, [CF₃SO₃]⁻

, [HCF₂CF₂SO₃]⁻

, [CF₃HFCCF₂SO₃]⁻

, [HCClFCF₂SO₃]⁻

, [(CF₃SO₂)₂N]⁻

, [(CF₃CF₂SO₂)₂N]⁻

, [(CF₃SO₂)₃C]⁻

, [CF₃CO₂]⁻

, [CF₃OCFHCF₂SO₃]⁻

, [CF₃CF₂OCFHCF₂SO₃]⁻

, [CF₃CFHOCF₂CF₂SO₃]⁻

, [CF₂HCF₂OCF₂CF₂SO₃]⁻

, [CF₂ICF₂OCF₂CF₂SO₃]⁻

, [CF₃CF₂OCF₂CF₂SO₃]⁻

, [(CF₂HCF₂SO₂)₂N]⁻

, [(CF₃CFHCF₂SO₂)₂N]⁻

, and F⁻

.

20. An apparatus according to claim 7 wherein the absorbent comprises one or more ionic liquids, and a refrigerant comprises from about 0.05 to about 99.95 mole percent of the mixture of refrigerant and absorbent over a temperature range from the evaporator temperature to the generator temperature at a pressure from vacuum to the critical pressure.

21. An apparatus according to claim 1 or 2 wherein the mixture of refrigerant and absorbent comprises an additive selected from the group consisting of lubricants, corrosion inhibitors, stabilizers and dyes.

22. An apparatus according to claim 1 or 2 that is fabricated as a refrigerator, a freezer, an ice machine, an air conditioner, an industrial cooling system, heater or heat pump.

2. An apparatus for temperature adjustment comprising

(a) an absorber that forms a mixture of a mixture of a refrigerant and an absorbent;

(b) a generator that receives the mixture from the absorber and heats the mixture to separate refrigerant, in vapor form, from the absorbent, and increases the pressure of the refrigerant vapor;

(c) a compressor that receives the vapor from the generator and further increases its pressure;

(d) a condenser that receives the vapor from the compressor and condenses the vapor under pressure to a liquid;

(e) a pressure reduction device through which the liquid refrigerant leaving the condenser passes to reduce the pressure of the liquid to form a mixture of liquid and vapor refrigerant;

(f) an evaporator that receives the mixture of liquid and vapor refrigerant that passes through the pressure reduction device to evaporate the remaining liquid to form refrigerant vapor; and

(g) a conduit that passes the refrigerant vapor leaving the evaporator to the absorber.

4. An apparatus according to claim 2 wherein the condenser is located in proximity to an object, medium or space to be heated.

6. An apparatus according to claim 2 wherein the evaporator is located in proximity to an object, medium or space to be cooled.

23. A process for adjusting the temperature of an object, medium or a space comprising

(a) absorbing refrigerant vapor with an absorbent to form a mixture;

(b) heating the mixture to separate refrigerant, in vapor form, from the absorbent and increase the pressure of the refrigerant vapor;

(c) condensing the refrigerant vapor under pressure to a liquid;

(d) reducing the pressure of the liquid refrigerant, and evaporating the refrigerant to form first and second portions of refrigerant vapor;

(e-1) mechanically increasing the pressure of the first portion of refrigerant vapor, and then repeating step (c) to subject the first portion of refrigerant vapor to condensation to liquid; and

(e-2) repeating step (a) to re-absorb, with the absorbent, the second portion of refrigerant vapor.

24. A process according to claim 23 wherein, in step (c), the refrigerant vapor is condensed to a liquid in proximity to the object, medium or space to heat the object, medium or space.

25. A process according to claim 23 wherein, in step (d), liquid refrigerant is evaporated to form refrigerant vapor in proximity to the object, medium or space to cool the object, medium or space.

29. A process according to claim 23 or 26 wherein the absorbent separated from refrigerant in step (b) is recirculated for use in a later step.

30. A process according to claim 23 or 26 wherein the refrigerant comprises one or more members of the group consisting of a hydrofluorocarbon, a hydrochlorofluorocarbon, a chlorofluorocarbon, a fluorocarbon, N₂, O₂, CO₂, NH₃, Ar, H₂, H₂O, and a non-fluorinated hydrocarbon, wherein the non-fluorinated hydrocarbon is selected from the group consisting of C₁to C₄ straight-chain, branched or cyclic alkanes and C₁ to C₄ straight-chain, branched or cyclic alkenes.

31. A process according to claim 23 or 26 wherein the absorbent comprises one or more ionic liquids.

32. A process according to claim 30 wherein the absorbent comprises one or more ionic liquids.

26. A process for adjusting the temperature of an object, medium or a space comprising

(a) absorbing refrigerant vapor with an absorbent to form a mixture;

(b) heating the mixture to separate refrigerant, in vapor form, from the absorbent and increase the pressure of the refrigerant vapor;

(c) further increasing the pressure of the refrigerant vapor mechanically;

(d) condensing the refrigerant vapor under pressure to a liquid;

(e) reducing the pressure of the liquid refrigerant, and evaporating the refrigerant to form refrigerant vapor; and

(f) repeating step (a) to re-absorb the refrigerant vapor with the absorbent.

27. A process according to claim 26 wherein, in step (d), the refrigerant vapor is condensed to a liquid in proximity to the object, medium or space to heat the object, medium or space.

28. A process according to claim 26 wherein, in step (e), liquid refrigerant is evaporated to form refrigerant vapor in proximity to the object, medium or space to cool the object, medium or space.