Working fluids for thermal energy conversion of waste heat from fuel cells using Rankine cycle systems

• US 7,428,816 B2
• Filed: 07/16/2004
• Issued: 09/30/2008
• Est. Priority Date: 07/16/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Hulse, Ryan, Wilson, David P, Singh, Rajiv R, Zyhowski, Gary J
• Primary Examiner(s): Nguyen; Hoang M
• Application Number:
  US10/892,913
• Publication Number:
  US 20060010872A1
• Time in Patent Office: 1,537 Days
• Field of Search: 606/51, 606/71, 252/67, 252/68
• US Class Current: 60/651
• CPC Class Codes: C09K 5/045 containing only fluorine as halogen
• CPC Class Codes: F01K 25/08 using special vapours
• CPC Class Codes: H01M 2250/405 Cogeneration of heat or hot water
• CPC Class Codes: H01M 8/04022 Heating by combustion
• CPC Class Codes: H01M 8/04029 Heat exchange using liquids
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 20/10 Process efficiency

Abstract

A process for recovering waste heat which comprises: (a) passing a liquid phase working fluid through a heat exchanger in communication with a process which produces the waste heat; (b) removing a vapor phase working fluid from the heat exchanger; (c) passing the vapor phase working fluid to an expander, wherein the waste heat is converted into mechanical energy; and (d) passing the vapor phase working fluid from the expander to a condenser, wherein the vapor phase working fluid is condensed to the liquid phase working fluid. The preferred working fluid is an organic Rankine cycle system working fluid comprising compounds having the following general structure:

where x, y, z, and m are each selected from the group consisting of: fluorine, hydrogen, R_f, and R, wherein R and R_f are each an alkyl, aryl, or alkylaryl of 1 to 6 carbon atoms, and wherein R_f is partially or fully fluorinated.

Claims

1. An organic Rankine cycle system comprising a working fluid comprising at least one compound having the following structure:

where x, y, z, and m are each selected from the group consisting of;

fluorine, hydrogen, R_f, and R, wherein R and R_f are each an alkyl, aryl, or alkylaryl of 1 to 6 carbon atoms, and wherein R_f is partially or fully fluorinated, wherein said compounds have the formula C_x′

F_y′

H_z′

where x′

is 12-b, where b is an integer from between about 0 to about 6, y′

is 2x′

−

z′

, and for x′

/2 and 2x′

/3 equals integers then z′

is 2x′

/3;

for x′

/2 and 3x′

/4 equals integers then z′

is 3x′

/4;

for x′

/2 not equal to integer then z′

is x′

−

2;

for x′

/2 and x′

/5 equals integers then z′

is x′

−

3; and

a heat exchanger.

2. The organic Rankine cycle system according to claim 1, wherein said working fluid further comprises (a) a saturated compound derived by reacting HF with any of said compounds or (b) a compound derived from said compounds by reduction with hydrogen.

4. The organic Rankine cycle system according to claim 1, wherein said working fluid further comprises at least one compound selected from the group consisting of:

water, silicones, aliphatic hydrocarbons, cyclic hydrocarbons, aromatic hydrocarbons, olefins, hydrofluorocarbons, hydrofluoroethers, perfluoroethers, alcohols, ketones, fluorinated ketones, fluorinated alcohols, esters, and phosphate esters.

14. A process for recovering heat that comprises:

(a) passing a liquid phase working fluid through at least a first heat exchanger in communication with a process which produces said waste heat;

(b) removing a warmed liquid phase working fluid from said first heat exchanger;

(c) passing said warmed liquid phase working fluid to at least a second heat exchanger, wherein said warmed liquid phase transfers heat to a working fluid according to claim 1.

17. The Organic Rankine system of claim 1, wherein b=0.

18. The Organic Rankine system of claim 1, wherein b=1.

19. The Organic Rankine system of claim 1, wherein b=2.

20. The Organic Rankine system of claim 1, wherein b=3.

21. The Organic Rankine system of claim 1, wherein b=4.

22. The Organic Rankine system of claim 1, wherein b=5.

23. The Organic Rankine system of claim 1, wherein b=6.

3. An organic Rankine cycle system working fluid comprising 4-trifluoromethyl-1,1,1,3,5,5,5-heptafluoro-2-pentene.

15. The organic Rankine system of claim 3, wherein the working fluid consists essentially of 4-trifluoromethyl-1,1,1,3,5,5,5-heptafluoro-2-pentene.

5. A process for recovering waste heat that comprises:

(a) passing a liquid phase working fluid through a heat exchanger in communication with a process which produces said waste heat;

(b) removing a vapor phase working fluid from said heat exchanger;

(c) passing said vapor phase working fluid to an expander, wherein said waste heat is convened into mechanical energy; and

(d) passing said vapor phase working fluid from said expander to a condenser, wherein said vapor phase working fluid is condensed to said liquid phase working fluid;

wherein said working fluids comprise at least one compound having the following structure;

where x, y, z, and m are each selected from the group consisting of;

fluorine, hydrogen, R_f, and R, wherein R and R_f are each an alkyl, aryl, or alkylaryl of 1 to 6 carbon atoms, and wherein R_f is partially or fully fluorinated, wherein said compounds have the formula C_x′

F_y′

H_z′

where x′

is 12-b, where b is an integer from between about 0 to about 6, y′

is 2x′

−

z′

, and for x′

/2 and 2x′

/3 equals integers then z′

is 2x′

/3;

for x′

/2 and 3x′

/4 equals integers then z′

is 3x′

/4;

for x′

/2 not equal to integer then z′

is x′

−

2;

for x′

/2 and x′

/5 equals integers then z′

is x′

−

3.

7. The process according to claim 5, wherein said process that produces waste heat is at least one selected from the group consisting of:

fuel cells, internal combustion engines, internal compression engines, external combustion engines, and turbines.

8. The process according to claim 5, further comprising a secondary heat exchanger loop disposed between said heat exchanger in step (a) and said process which produces said waste heat.

9. The process according to claim 8, wherein said secondary heat exchanger loop comprises passing a secondary fluid in communication with both said heat exchanger and said process which produces said waste heat, thereby transferring said waste heat from said process to said secondary fluid which thereafter transfers said waste heat from said secondary fluid to said liquid phase working fluid.

10. The process according to claim 9 wherein said secondary fluid comprises at least one compound having the following structure:

where x, y, z, and m are each selected from the group consisting of;

fluorine, hydrogen, R_f, and R, wherein R and R_f are each an alkyl, aryl, or alkylaryl of 1 to 6 carbon atoms, and wherein R_f is partially or fully fluorinated.

11. The process according to claim 9, wherein said secondary fluid is at least one high-boiling point fluid.

12. The process according to claim 9, wherein said secondary fluid is at least one selected from the group consisting of:

glycols, silicones and other essentially non-volatile fluids.

13. The process according to claim 5, wherein said process that produces waste heat is at least one operation associated with at least one industry selected from the group consisting of:

oil refineries, petrochemical plants, oil and gas pipelines, chemical industry, commercial buildings, hotels, shopping malls, supermarkets, bakeries, food processing industries, restaurants, paint curing ovens, furniture making, plastics molders, cement kilns, lumber kilns, calcining operations, steel industry, glass industry, foundries, smelting, air-conditioning, refrigeration, and central heating.

16. The process of claim 10, wherein said secondary fluid comprises 4-trifluoromethyl-1,1,1,3,5,5,5-heptafluoro-2-pentene.

24. The process according to claim 9 wherein said secondary fluid comprises at least one working fluid comprising at least one compound selected from the group consisting of:

1,1,1,2,2,4,4,4-octafluorobutane,

2-trifluoromethyl 1,1,1,3,3-pentafluoropropane,

1,1,1,2,2,3,3,4-octafluorobutane,

1,1,1,2,2,3,3,4,4-nonafluorobutane,

trifluoromethyl 1,1,1,2,2-pentafluoropropyl ether or 3-trifluoromethoxy 1,1,1,2,2, pentafluoropropane,

1,1,1-trifluoroethyl perfluoroethyl ether or 2-perfluoroethoxy 1,1,1-trifluoroethane,

2-trifluoromethyl 1,1,1,3,3,3-hexafluoropropane or 2-H perfluoroisobutane,

methyl (1,1,1,2,3,3,3-heptafluoropropane)-2-ether or 2-methoxy perfluoropropane,

methyl 1,1,1,2,2,3,3-heptafluoropropane ether or 3-methoxy perfluoropropane,

1,2,2,2-tetrafluoroethyl 1,1,1,2,2,3,3-heptafluoropropane ether or 2-perfluoropropoxy 1,1,1,2-tetrafluoroethane,

perfluoro-tertiary butyl alcohol,

1,1,2,2,3,3,4,4-octafluorobutane,

1,1,1,2,2,3,3,4,4,5,5-undecafluoropentane,

1,1,1,2,3,4,4,5,5,5-decafluoropentane,

4-trifluoromethyl-1,1,1,3,5,5,5-heptafluoro-2-pentene,

cyclo-1,1,2,2,3,4-hexafluorobutane,

cyclo-1,1,2,2,3,3,4,4,5,5-decafluoropentane, and

H-dodecafluoropentane isomers.

6. A process for recovering waste heat that comprises:

(a) passing a liquid phase working fluid through a heat exchanger in communication with a process which produces said waste heat;

(b) removing a vapor phase working fluid from said heat exchanger;

(c) passing said vapor phase working fluid to an expander, wherein said waste heat is converted into mechanical energy; and

(d) passing said vapor phase working fluid from said expander to a condenser, wherein said vapor phase working fluid is condensed to said liquid phase working fluid;

wherein said working fluid comprises 4-trifluoromethyl-1,1,1,3,5,5,5-heptafluoro-2-pentene.