Secondary loop refrigeration system
AssigneeMinnesota Mining and Manufacturing Company
InventorGregory J. Sherwood
Life of this patent
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Abstract
A method and apparatus are provided for using certain hydrofluoroethers (HFEs) as low temperature heat transfer media in secondary loop refrigeration systems. These materials exhibit a low, somewhat linear Temperature Difference Factor over the temperature range of −15° C. to −65° C., making them ideal for use as low temperature heat transfer media. The HFEs of the present invention are nonflammable, nontoxic, environmentally benign, and have a high heat transfer capacity and low viscosity over the required operating temperatures. Furthermore, since these materials have high boiling points and low freezing points, they are not prone to phase changes over the required operating temperatures, and do not require pressurized systems.
Claims21
A refrigeration system, comprising:
- a display case for displaying refrigerated goods;
- first second heat transfer means for transferring heat from said display case to a first second heat transfer medium;
- and
- second first heat transfer means for transferring heat from said first second heat transfer medium to a second first heat transfer medium;
- wherein said second first heat transfer means cools said first second heat transfer medium to less than about −15° C., and wherein said first second heat transfer medium comprises an ether of the formula
- R1—O—R2
- wherein R1 and R2 are alkyl groups, and wherein at least one of R1 and R2 is at least partially fluorinated.
A refrigeration system, comprising:
- a display case for displaying refrigerated goods;
- a first refrigeration loop with a first refrigerant disposed therein;
- a second refrigeration loop with a first refrigerant disposed therein;
- a refrigeration coil, in open communication with said second refrigeration loop, for transferring heat from said display case to said second refrigerant;
- and
- a heat exchanger for transferring heat from said second refrigerant to said first refrigerant;
- wherein said first second refrigerant comprises a fluorinated ether.
Dependencies are inferred from the claim text.