Heat transfer methods, systems and compositions
Disclosed are methods for providing heating and/or cooling of the type comprising evaporating refrigerant liquid and condensing refrigerant vapor in a plurality of repeating cycles, where the method comprises (a) providing the refrigerant comprising at least about 5% by weight of a lower alkyl iodofluorocarbon; and (b) exposing at least a portion of said refrigerant in at least a portion of said plurality of said cycles to a sequestration material comprising: i) copper or a copper alloy; ii) a molecular sieve (preferably a zeolite), comprising copper, silver, lead or a combination thereof; iii) an anion exchange resin, and iv) a combination of two or more of these, wherein said exposing temperature is preferably above about 20 C.
1. A method for providing heat transfer of the type comprising evaporating refrigerant liquid to produce a refrigerant vapor, compressing in a compressor at least a portion of the refrigerant vapor and condensing refrigerant vapor in the condenser in a plurality of repeating cycles, said method comprising:
(a) providing a refrigerant comprising at least about 5% by weigh of a lower alkyl iodofluorocarbon;
(b) optionally providing lubricant for said compressor; and
(b) exposing at least a portion of said refrigerant and/or at least a portion of said lubricant in at least a portion of said plurality of said cycles to a sequestration material included in a filtration element, said sequestration material comprising one or more of:
i. copper or a copper alloy,
ii. activated alumina
iii. a zeolite molecular sieve comprising copper, silver, lead or a combination thereof,
iv an anion exchange resin, and
v. a moisture-removing material,
wherein said sequestration material comprises at least activated alumina and
wherein said exposing temperature is above about 10° C.
2. The method of claim 1 , wherein said molecular sieve is present and wherein said molecular sieve is a zeolite.
3. The method of claim 1 wherein the sequestration material further comprises a molecular sieve comprising copper, silver, lead or a combination thereof.
4. The method of claim 1 wherein the sequestration material further comprises an anion exchange resin.
5. The method of claim 1 , wherein the sequestration material comprises copper or a copper alloy.
6. The method of claim 1 , wherein the sequestration material comprises copper, or a copper alloy, and a molecular sieve comprising copper, silver, lead or a combination thereof.
7. The method of claim 1 , wherein the sequestration material comprises a combination of activated alumina, a zeolite molecular sieve comprising copper, silver, lead or a combination thereof, an anion exchange resin, and a moisture-removing material.
8. The method of claim 1 were said sequestration material is in the form of a solid core.
9. The method of claim 8 were said solid core is located in a liquid line of said condenser.
10. The method of claim 8 wherein lubricant for said compressor is present and wherein said method further comprises providing an oil separator and wherein said solid core is located in said oil separator.
11. The method of claim 1 wherein lubricant for said compressor is present and wherein said method further comprises providing an oil separator and wherein said sequestration material is located in said oil separator.
12. The method of claim 1 wherein when the sequestration material comprises an anion exchange resin, the anion exchange resin comprises a positively charged matrix and exchangeable anions selected from chloride anions (Cl − ) or hydroxide anions (OH − ).
13. The method of claim 1 wherein when the sequestration material comprises an anion exchange resin, the anion exchange resin is a weakly basic anion exchange resin.
14. The method of claim 1 wherein when the sequestration material comprises copper or a copper alloy, the copper or copper alloy has a surface area of from about 0.01 to about 1.5 m 2 per kg of refrigerant.
15. The method of claim 1 wherein the sequestration material comprises a moisture-removing molecular sieve.
16. The method of claim 14 wherein the copper or copper alloy has a surface area of from about 0.02 to about 0.5 m 2 per kg of refrigerant.
17. The method of claim 14 wherein the copper or copper alloy has a surface area of about 0.08 m 2 per kg of refrigerant.