Refrigeration System With Dual Refrigerants and Liquid Working Fluids

Abstract

In one embodiment, the present invention relates to the use of ionic liquids and gas refrigerants in a refrigerant composition in a temperature adjustment system, such as a refrigeration system.

Claims

1. A refrigeration system comprising a refrigerant composition and a compression refrigeration apparatus, wherein the refrigerant composition comprises at least one gas refrigerant and a working liquid selected from the group consisting of water, alcohol, ionic liquids and mixtures thereof; wherein the compression refrigeration apparatus comprises: (a) an absorption/reaction chamber configured to receive the gas refrigerant that is passed from a compressor into the absorption/reaction chamber; wherein the compressor is optionally an oil-lubricated compressor or an oil-free compressor; (b) an evaporator/desorber chamber configured to pass an unsaturated working liquid to the absorption/reaction chamber; wherein the one or more gas refrigerants reversibly react in the absorption/reaction chamber under high pressure and absorbed by the unsaturated working liquid to form a saturated working liquid; (c) a hot side heat exchanger configured to be connected to the absorption/reaction chamber, where heat is removed from the refrigeration composition; (d) a pressure reduction device configured to receive the saturated working liquid from the absorption/reaction chamber and to pass the saturated working liquid to the evaporator/desorption chamber; wherein the pressure reduction device comprise a valve or a capillary tube; wherein the gas refrigerant vaporizes from the saturated working liquid under low pressure in the evaporator/desorption chamber to form the unsaturated working liquid; (e) a cold side heat exchanger configured to be connected to the evaporator/desorption chamber, where heat is absorbed by the refrigeration composition; and (f) a conduit configured to receive the gas refrigerant from the evaporator/desorption chamber and to return the gas refrigerant to the compressor.

2. The refrigeration system according to claim 1, wherein the composition comprises two gas refrigerants.

3. The refrigeration system according to claim 1, wherein the composition comprises dual gas refrigerants that can undergo reversible reactions, and further comprising a liquid working fluid.

4. The refrigeration system according to claim 1, wherein the ionic liquid comprises a cation, wherein the cation is selected from a group consisting of cations of ammonium, imidazolium, pyridinium, phosphonium and sulfonium; or any combination thereof.

5. The refrigeration system according to claim 1, wherein the ionic liquid comprises of a single ionic liquid or a mixture of 1, 2, 3 or more ionic liquids.

6. The refrigeration system according to claim 1, wherein the gas refrigerant is selected from an acidic gas and a basic gas; wherein the basic gas refrigerant is selected from a group consisting of methylamine, ethylamine and ammonia; or any combination thereof, and wherein the acidic gas refrigerant is selected from a group consisting of carbon dioxide, nitrous dioxide and sulfur dioxide; or any combination thereof.

7. The refrigeration system according to claim 1, wherein the gas refrigerant comprises ammonia and carbon dioxide.

8. The refrigeration system according to claim 1, wherein the composition comprises additives such as corrosion inhibitors, antifoaming agents and antioxidants, or mixtures thereof.

Description

DESCRIPTION OF THE FIGURE

[0173] FIG. 1 is a general depiction of an exemplary refrigeration system.

[0174] FIG. 2 is a schematic diagram of a simple vapor compression refrigeration system.

[0175] FIG. 3 is a schematic diagram of a simple absorption refrigeration system.

EXAMPLES

[0176] FIG. 1 illustrates an exemplary embodiment of the present application. In one aspect, the IL in the composition for the refrigeration system is 1-butyl-3-methylimidazoliumbis(trifluoromethylsulfonyl)imide:

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[0177] In the condenser, two gas refrigerants, ammonia and CO.sub.2, are dissolved into ILs and react. The selection of the IL enables the reaction products to be soluble within the liquid. As the refrigerants react in the ionic fluid, further absorption from the gaseous state is facilitated due to the solubility equilibrium shift caused by the removal of each of the gas species in the IL due to the reaction between the refrigerant species. Reduction of the concentration of product caused by the pumping of product free IL from the evaporator further shifts the reaction forward and reduces the required compression work.

[0178] In FIG. 1, as representative embodiments, the following control strategy may be employed:

[0179] Cold Side Pump: Operates independently and adjusts circulation rate to maintain the desired minimum delta T between the fluid exiting the heat exchanger and the inlet temperature of the fluid into the pump.

[0180] HotSidePump: Operates independently and adjusts circulation rate to maintain the desired maximum delta T between the fluid exiting the heat exchanger and the inlet temperature of the fluid into the pump.

[0181] Evaporator/Desorption Pump: Operates to maintain the desired level in the desorption chamber and the absorption chamber. Level affected by the flow control valve; that may be used to drain absorption tank and fill desorption tank. Minimum flow limited by compression rate of refrigerant.

[0182] Compressor Duty: Limited by the maximum pressure and temperature allowed into the absorption tank. Limited by the maximum temperature duty required of the system.

[0183] Limited by efficiency requirements of the system. For example, as more work is done by the compressor, heat exchange increases, but efficiency falls. The controller can operate to maximize efficiency by limiting duty or vice versa.

[0184] FIG. 3 illustrates an exemplary embodiment of the present application using absorption refrigeration system. The foregoing examples of the related art and limitations are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings or figures as provided herein.

[0185] While a number of exemplary embodiments, aspects and variations have been provided herein, those of skill in the art will recognize certain modifications, permutations, additions and combinations and certain sub-combinations of the embodiments, aspects and variations. It is intended that the following claims are interpreted to include all such modifications, permutations, additions and combinations and certain sub-combinations of the embodiments, aspects and variations are within their scope.