Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B15/00—Sorption machines, plants or systems, operating continuously, e.g. absorption type
  • F25B15/02—Sorption machines, plants or systems, operating continuously, e.g. absorption type without inert gas
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
  • C09K5/02—Materials undergoing a change of physical state when used
  • C09K5/04—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa
  • C09K5/047—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for absorption-type refrigeration systems
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B27/00—Machines, plants or systems, using particular sources of energy
  • F25B27/002—Machines, plants or systems, using particular sources of energy using solar energy
  • F25B27/007—Machines, plants or systems, using particular sources of energy using solar energy in sorption type systems
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
  • F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
  • F25B9/006—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant containing more than one component
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/12—Inflammable refrigerants
  • F25B2400/121—Inflammable refrigerants using R1234
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A30/00—Adapting or protecting infrastructure or their operation
  • Y02A30/27—Relating to heating, ventilation or air conditioning [HVAC] technologies
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
  • Y02B30/62—Absorption based systems
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/10—Process efficiency

Definitions

• This invention relates to absorption refrigeration systems that employ refrigerants with low global warming potential (GWP) and low ozone depletion potential (ODP).
• GWP global warming potential
• ODP ozone depletion potential
• Absorption refrigeration is a more economical alternative to compression refrigeration when a source of waste or other low-cost heat (e.g. solar heating) is available.
• Both absorption refrigerators and vapor compression refrigerators use a refrigerant with a very low boiling point. In both types, when this refrigerant evaporates or boils, it takes some heat away with it, providing the cooling effect.
• absorption refrigeration and vapor compression refrigeration differ in the way the refrigerant is changed from a gas back into a liquid so that the cycle can repeat.
• a vapor compression refrigerator uses an electrically-powered compressor to increase the pressure on the gas, and then condenses the hot high pressure gas back to a liquid by heat exchange with a coolant (usually air).
• An absorption refrigerator changes the gas back into a liquid using a different method that needs only a low-power pump, or optionally only heat thereby eliminating the need for moving parts.
• An important aspect of most absorption refrigeration cycle is the refrigerant/absorbent pair which enables the entire system.
• An absorbent is used to absorb the refrigerant at a condition where the absorbent is a liquid and the refrigerant would typically be a gas.
• refrigerant/absorbent mixture can then be pumped as a liquid to a higher pressure, thus avoiding the need to use of a compressor.
• the high pressure liquid mixture is then separated at high pressure and temperature yielding a high pressure vapor refrigerant, which is fed to the condenser, and the absorbent in liquid form, which is recycled back to pick up more refrigerant.
• Two of the most common absorption refrigeration pairs are H 3 -water and water-LiBr.
• H 3 -water uses H 3 as the refrigerant and water as the absorbent.
• H 3 performs well as a refrigerant in many applications.
• the toxicity of NH 3 restricts its use in public occupied spaces.
• ammonia is highly corrosive and incompatible with copper, a common material in cooling systems.
• Water-LiBr is the other commonly used refrigerant pair in absorption systems. Water has two drawbacks: water freezes below 0°C, and due to low vapor density, large equipment sizing is required, making the solution impractical in space constrained locations.
• the present invention relates to the discovery of refrigerant and absorbent pairs for use in absorption refrigeration systems.
• hydrofluoroolefins and/or hydrochlorofluoroolefins are at least partially soluble in an oil such as polyalkyene glycol (PAG) oil, poly alpha olefin oil, mineral oil, and polyol ester (POE) oil.
• PAG polyalkyene glycol
• POE polyol ester
• refrigerants are characterized as having a low-GWP (i.e., ⁇ 1000, and preferably ⁇ 100 relative to C0 2 ), a low or no appreciable ozone depletion potential, and are non- toxic and non-flammable.
• an aspect of this invention involves a method for providing refrigeration comprising: (a) evaporating a first liquid-phase refrigerant stream comprising a refrigerant selected from the group consisting of one or more hydrofluoroolefins, one or more
• an absorption refrigeration system comprising: (a) a refrigerant selected from the group consisting of one or more hydrofluoroolefins, one or more hydrochlorofluoroolefins, and blends thereof; (b) a solvent selected from the group consisting of a polyalkyene glycol oil, a poly alpha olefin oil, a mineral oil, a polyolester oil, and combinations thereof; (c) an evaporator suitable for evaporating said refrigerant; (d) a condenser suitable for condensing said refrigerant; (e) a separator suitable for thermodynamically separating a solution comprising said refrigerant dissolved in said solvent into a vapor refrigerant component and a liquid solvent component; and (f) at least one gas- dissolving subsystem comprising a mixer suitable for mixing said
• the terms "low-pressure vapor-phase refrigerant” and "high-pressure vapor-phase refrigerant” are relative to one another. That is, a low-pressure vapor-phase refrigerant has a pressure above 0 psia, but lower than the pressure of the high-pressure vapor- phase refrigerant. Likewise, the high-pressure vapor-phase refrigerant has a pressure below the composition's critical point, but higher than the pressure of the low-pressure vapor-phase refrigerant.
• the term "substantially all" with respect to a composition means at least about 90 weight percent based upon the total weight of the composition.
• the invention provides an absorption refrigeration system comprising: (a) a refrigerant selected from the group consisting of one or more hydrofluoroolefins, one or more hydrochlorofluoroolefins, and blends thereof; (b) a solvent selected from the group consisting of a polyalkyene glycol oil, a poly alpha olefin oil, a mineral oil, a polyolester oil, and combinations thereof; (c) an evaporator suitable for evaporating said refrigerant; (d) a mixer suitable for mixing said refrigerant with said solvent, wherein said mixer is fluidly connected to said evaporator; (e) an absorber suitable for dissolving at least a portion of said refrigerant into said solvent to produce a solution, wherein said absorber is fluidly connect to said mixer; (f) a pump fluidly connected to said absorber; (g) a heat exchanger fluidly connected to said pump, wherein the heat exchanger in certain embodiments absorb
• the invention provides environmentally friendly, economical refrigeration processes. Additional embodiments and advantages will be readily apparent to the skilled artisan on the basis of the disclosure provided herein. BRIEF DESCRIPTION OF THE DRAWINGS
• Figure 1 is a graph of the solubility of trans-l,3,3,3-tertafluoropropene (1234ze(E)) in PAG refrigerant compressor oil as determined according to Example 2.
• Figure 2 is a graph of the solubility of trans-l,3,3,3-tetrafluoropropene (1234ze(E)) in POE oil as determined according to Example 5.
• Figure 3 is a graph of the solubility of trans-l-chloro-3,3,3-trifluoropropene (1233zd(E)) in mineral oil as determined according to Example 8.
• Figure 4 is a simplified schematic of a single effect absorption refrigeration cycle.
• Figure 5 is a simplified schematic of a double effect absorption refrigeration cycle.
• the present invention relates to the discovery of refrigerant and absorbent pairs for use in connection with low-grade heat sources, and in particular low grade heat sources such as waste-heat sources, solar-derived heat source, geothermal derived heat sources and combinations of these.
• low-grade heat sources such as waste-heat sources, solar-derived heat source, geothermal derived heat sources and combinations of these.
• Residential and commercial buildings are large consumers of electric energy with fluctuating demand. Electricity is produced by the most efficient equipment running nearly continuously. However to meet peak demand, less efficient equipment is used, usually fueled by natural gas or oil. Natural gas prices are volatile, and dependence on oil dilutes U.S. security. However, peak demand places additional burden on the electrical grid. The reliability of electrical service is improved when peak demand is flattened.
• the present absorption system provides peak cooling at times of peak demand. In other applications, such as heat pumps, similar improvements are observed.
• a non-concentrated array is typically a self-cleaning, stationary structure that absorbs only the sunlight that directly impinges the thermal absorbing coating.
• Non-concentrated solar absorbers are typically capable of producing temperatures up to about 140°C for evacuated tube designs and generally up to about 90°C for advanced flat plate designs.
• the present invention may include either of these designs or a combination of both.
• it includes evacuated tube specifications to produce a solar air conditioning system reaching a maximum temperature of 120°C.
• the heat collected from the solar collector operates as a "thermal compressor" to the refrigeration system. That is, it facilitates heating the refrigerant and absorbent such that the two may be separable under high temperature/high pressure conditions.
• the advantages of absorption systems are simplicity, reliability and long term durability due to very few mechanical parts.
• the only moving piece of an absorption system is a liquid pump.
• Absorption systems have the disadvantages of limited working fluids. Until now, absorption refrigeration has been limited to industrial applications because safe refrigerant/absorbent fluid pairs were not available.
• hydrochlorofluoroolefin refrigerant is used in the absorpti on-type refrigeration system as a working fluid, i.e., a fluid that changes states from gas to liquid or vice versa via a working fluid, i.e., a fluid that changes states from gas to liquid or vice versa via a working fluid, i.e., a fluid that changes states from gas to liquid or vice versa via a working fluid, i.e., a fluid that changes states from gas to liquid or vice versa via a
• thermodynamic cycle This phase change is facilitated by dissolving the vapor-phase refrigerant in an oil solvent to form a solution.
• a pump and heat exchanger are used to efficiently increase the solution's pressure and temperature, respectively.
• the pressurized and heated solution is then flashed to produce a refrigerant vapor at high pressure.
• This high pressure vapor is then passed through a condenser and evaporator to transfer heat from a system to be cooled.
• Particularly preferred refrigerants include hydrohalopropenes, more preferably tetrahalopropenes, even more preferably tetrafluoropropenes and mono-chloro-trifluoropropenes, even more preferably tetrahalopropenes having a -CF 3 moiety.
• the refrigerant including one or a combination of 2,3,3, 3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, or 1- chloro-3,3,3-trifluoropropene, including all stereoisomers thereof, such as trans-l, 3,3,3- tertafluoropropene, cz ' s-l,3,3,3-tertafluoropropene, /ra «s-l-chloro-3,3,3-trifluoropropene, cis-l- chloro-3,3,3-trifluoropropene and 3,3,3-trifluoropropene.
• Certain useful refrigerants also comprise a mixture of two or more hydrofluoroolefins, hydrochlorofluoroolefins, as well as mixtures of both hydrofluoroolefins and hydrochlorofluoroolefins.
• the refrigerant is or includes 2,3,3,3- tetrafluoropropene (HFO-1234yf) and the solvent (or absorbent) is selected from polyalkyene glycol oil, a poly alpha olefin oil, a mineral oil and a polyol ester oil.
• the refrigerant is or includes 2,3,3,3-tetrafluoropropene (HFO-1234yf) and the solvent (or absorbent) is selected from a polyalkyene glycol oil and/or a polyol ester oil.
• the refrigerant is or includes 2,3,3,3-tetrafluoropropene (HFO-1234yf) and the solvent (or absorbent) is selected from a polyalkyene glycol oil and/or a polyol ester oil.
• HFO-1234yf 2,3,3,3-tetrafluoropropene
• the solvent (or absorbent) is selected from a polyalkyene glycol oil and/or a polyol ester oil.
• the refrigerant comprises at least about 50%> by weight, more preferably at least about 75%> by weight and even more preferably in non-limiting embodiments comprises about 100%> of 2,3,3,3-tetrafluoropropene (HFO-1234yf) and the solvent (or absorbent) comprises at least about 50%> by weight, more preferably at least about 75%> by weight and even more preferably in non-limiting embodiments comprises about 100%) of polyalkyene glycol oil.
• HFO-1234yf 2,3,3,3-tetrafluoropropene
• the refrigerant comprises at least about 50%> by weight, more preferably at least about 75%> by weight and even more preferably in non-limiting embodiments comprises about 100%> of 2,3,3,3-tetrafluoropropene (HFO-1234yf) and the solvent (or absorbent) comprises at least about 50%> by weight, more preferably at least about 75%> by weight and even more preferably in non-limiting embodiments comprises about 100%) of polyol ester oil.
• HFO-1234yf 2,3,3,3-tetrafluoropropene
• the refrigerant is or includes 1,3,3,3- tetrafluoropropene (HFO-1234ze) and the solvent (or absorbent) is selected from polyalkyene glycol oil, a poly alpha olefin oil, a mineral oil and a polyol ester oil.
• the refrigerant is or includes 1,3,3,3-tetrafluoropropene (HFO-1234ze) and the solvent (or absorbent) is selected from a polyalkyene glycol oil and/or a polyol ester oil.
• 1,3,3,3-tetrafluoropropene comprises, consists essentially of, or consists of the trans isomer.
• the refrigerant comprises at least about 50% by weight, more preferably at least about 75% by weight and even more preferably in non-limiting embodiments comprises about 100%> of transl,3,3,3-tetrafluoropropene (HFO-1234ze(E)) and the solvent (or absorbent) comprises at least about 50% by weight, more preferably at least about 75%) by weight and even more preferably in non-limiting embodiments comprises about 100% of polyol ester oil.
• HFO-1234ze(E) transl,3,3,3-tetrafluoropropene
• the refrigerant comprises at least about 50% by weight, more preferably at least about 75% by weight and even more preferably in non-limiting embodiments comprises about 100% of transl,3,3,3-tetrafluoropropene (HFO-1234ze(E)) and the solvent (or absorbent) comprises at least about 50% by weight, more preferably at least about 75%) by weight and even more preferably in non-limiting embodiments comprises about 100%) of polyalkyene glycol oil.
• HFO-1234ze(E) transl,3,3,3-tetrafluoropropene
• the refrigerant is or includes l-chloro-3,3,3- trifluoropropene (HCFO-1233zd) and the solvent (or absorbent) is selected from polyalkyene glycol oil, a poly alpha olefin oil, a mineral oil and a polyol ester oil.
• the refrigerant is or includes l-chloro-3,3,3-trifluoropropene (HCFO-1233zd) and the solvent (or absorbent) is selected from a polyalkyene glycol oil, a polyol ester oil, and/or a mineral oil.
• l-chloro-3,3,3-trifluoropropene (HCFO-1233zd) comprises, consists essentially of, or consists of the trans isomer.
• the refrigerant comprises at least about 50% by weight, more preferably at least about 75% by weight and even more preferably in non-limiting embodiments comprises about 100% of transl-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)) and the solvent (or absorbent) comprises at least about 50% by weight, more preferably at least about 75%) by weight and even more preferably in non-limiting embodiments comprises about 100%) of polyol ester oil.
• HCFO-1233zd(E) transl-chloro-3,3,3-trifluoropropene
• the refrigerant comprises at least about 50% by weight, more preferably at least about 75% by weight and even more preferably in non-limiting embodiments comprises about 100% of transl-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)) and the solvent (or absorbent) comprises at least about 50% by weight, more preferably at least about 75%) by weight and even more preferably in non-limiting embodiments comprises about 100%) of polyalkylene glycol oil.
• HCFO-1233zd(E) transl-chloro-3,3,3-trifluoropropene
• the refrigerant comprises at least about 50% by weight, more preferably at least about 75% by weight and even more preferably in non-limiting embodiments comprises about 100% of transl-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)) and the solvent (or absorbent) comprises at least about 50% by weight, more preferably at least about 75%) by weight and even more preferably in non-limiting embodiments comprises about 100% of mineral oil.
• HCFO-1233zd(E) transl-chloro-3,3,3-trifluoropropene
• the refrigerant comprises at least about 50% by weight, more preferably at least about 75% by weight and even more preferably in non-limiting embodiments comprises about 100% of transl-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)) and the solvent (or absorbent) comprises at least about 50% by weight, more preferably at least about 75%) by weight and even more preferably in non-limiting embodiments comprises about 100% of alkylbenzene oil.
• HCFO-1233zd(E) transl-chloro-3,3,3-trifluoropropene
• the refrigerant comprises at least about 50% by weight, more preferably at least about 75% by weight and even more preferably in non-limiting embodiments comprises about 100% of transl-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)) and the solvent (or absorbent) comprises at least about 50% by weight, more preferably at least about 75%) by weight and even more preferably in non-limiting embodiments comprises about 100% of silicone oil.
• HCFO-1233zd(E) transl-chloro-3,3,3-trifluoropropene
• the refrigerant and solvent are mixed in proportions and under conditions effective to form a solution in which the refrigerant is dissolved in the solvent.
• the mixture of refrigerant and solvent is in proportions in which a substantial portion, and more preferably substantially all, of the refrigerant mixed with the solvent is dissolved in the solvent. That is, it is preferred that the amount of refrigerant to be mixed with the solvent is below the saturation point of the solvent at the operating temperature and pressure of the refrigerant system. Maintaining the refrigerant concentration below the saturation point decreases the likelihood that vapor refrigerant will reach the pump, where it could lead to cavitations.
• the refrigerant and solvent may be mixed by a mixer.
• Preferred mixers include static mixers and aspirators (i.e., venturi pump).
• the mixer is a simple junction of two transfer lines (e.g., pipes, tubes, hoses, and the like) that produces a turbulent flow, such as a T-fitting.
• Dissolution of the low-pressure vapor phase refrigerant in the oil solvent preferably occurs at refrigerant temperature of about -10°C to about 30°C, preferably from about 0°C to about 30°C, preferably about 0°C to about 10°C.
• the dissolution of the refrigerant in the solvent occurs, at least to a major portion, in an absorber.
• the absorber can be of any type that is suitable for dissolving a refrigerant gas into an oil-based solvent. Examples of absorbers include heat exchangers through or around which a cooling medium is circulated.
• the solution comprising the refrigerant and solvent is pumped against a means of resistance to increase the pressure of the solution.
• Pumping the liquid solution to a high operating pressure typically requires significantly less energy compared to compressing a vapor refrigerant using a compressor.
• pumps are typically less costly to install and maintain compared to compressors. This energy and cost savings is a distinct advantage of the present invention over conventional compression-type refrigeration systems.
• the solution is also heated, preferably after being pressurized. Heating is preferably accomplished using a heat exchanger, such as shell-and-tube heat exchangers and plate heat exchangers or a distillation column. In preferred embodiments, heating the solution involves transferring heat from a low-grade heat source, a waste-heat recovery unit (WHRU), a geothermal source, a solar-derived source and the like.
• WHRU waste-heat recovery unit
• a WHRU can include, for example, heat from a hot gas or liquid stream, such an exhaust gas from a gas turbine or waste gas from a power plant or refinery.
• the working medium for the heat source can vary depending on the particulars of individual application, but is preferably in many applications water - either pure or with triethylene glycol (TEG), thermal oil or other mediums conducive to heat transfer.
• TOG triethylene glycol
• heating the solution involves direct heating from combustion of a fuel such a propane, with heat derived from a solar and/or geothermal source being highly preferred embodiments, as discussed herein.
• thermodynamic separation process After the solution is heated and pressurized, it is subjected to a thermodynamic separation process to produce a vapor refrigerant fraction and a liquid solvent fraction.
• thermodynamic separation processes include column distillation and flashing. Since the two fractions are in different phases, they can be separated easily.
• the liquid solvent phase is recirculated back to the mixer, while the vapor phase comprising the refrigerant is transferred to a condenser where at least a portion, and preferably substantially all, of the refrigerant is converted from its vapor phase to a liquid phase.
• condenser useful in the invention are not particularly limited provided that they are suitable for condensing a hydrofluoroolefin or hydrochlorofluoroolefin refrigerant.
• condensers include horizontal or vertical in-shell condensers and horizontal or vertical in-tube condensers.
• the liquid phase refrigerant is preferably passed through an expansion valve to lower the pressure of the refrigerant and, correspondingly, cool the refrigerant.
• the cooled, throttled refrigerant can be in a liquid-phase, vapor-phase, or a mixed-phase.
• the type of evaporator used to evaporate the liquid-phase refrigerant is not particularly limited provided that it is suitable for evaporating a hydrofluoroolefin or hydrochlorofluoroolefin refrigerant.
• useful evaporators include forced circulation evaporators, natural circulation evaporator, long-tube and short-tube vertical evaporators, falling film evaporators, horizontal tube evaporators, and plate evaporators.
• the refrigerant After the refrigerant is evaporated it becomes a low-pressure vapor-phase refrigerant preferably having a temperature of about 30°C to about 60°C, more preferably about 40°C to about 50°C.
• the low-pressure vapor-phase refrigerant is preferably recirculated back to the mixer.
• the processes of the present invention are preferably a closed-loop system wherein both the refrigerant and solvent are recirculated.
• Absorption refrigeration systems according to this invention preferably involve a single, double, or triple effect absorption refrigeration process. Single and double effect processes are described in the Examples and figures described below.
• a steady state system model using ideal components was developed to look at the use of low GWP refrigerant HFO-1234yf with a lubricant (e.g. a polyalkylene glycol or polyol ester) as the absorbent.
• the efficiency or coefficient of performance (COP) of the absorption cycle was calculated as Q C ooiing/(Qin+W p ). Even though Q in is considered waste heat in many applications and is a "free" source of energy in the solar application, this is the best way to compare potential refrigerant pairs.
• the modeling first looked at a H 3 -water absorption cycle and found operation with a COP of about 0.6 at an evaporator temperature of 5°C and an ambient temperature of 40°C. For the ideal HFO-1234yf with lubricant model, the COP was found to be about 0.6 for the same operating parameters, i.e., when operated at an evaporator temperature of 2°C and an ambient temperature of 40°C.
• Table 1 Comparison of annual energy consumption and peak electricity demand for a typical large store (100,000 ft 2 ) using conventional roof top units versus absorption assisted roof top units (assuming 450 tons of total cooling).
• This innovation involves the use of solar collectors at reasonably high temperature output, which qualifies evacuated tube solar collectors (commercially available products) to be used for this application.
• evacuated tube solar collectors commercially available products
• the required install area per ton of cooling would be approximately 18 m 2 for an 800 W/m 2 solar day or rather an array that accounts approximately l/3 rd of the roof area in the above analysis.
• This also allows the store to avoid peak electrical demand charges by providing "free" cooling during peak demand and ultimately reduces the peak electrical grid load.
• Example 2 The data from Example 2 was used to develop a single effect absorption cycle.
• a absorption refrigeration system as disclosed in Figure 4 is used.
• polypropylene glycol dimethyl ether-based oil is mixed with a liquid 1234ze(E) refrigerant in a closed mixer (which can be a simple "T" joint connecting two or more lines).
• the mixture is passed to an absorber where the gaseous 1234ze(E) dissolves to the extent indictated in Figure 2 at the to the oil.
• the liquid mixture is passed to a pump that pressurizes the mixture and passes the mixture to a heat exchanger/boiler. In the boiler, heat is exchanged with the mixture.
• the source of that heat can be thermal heat from a solar collector external to the heat exchanger.
• the temperature of the mixture is raised to a temperature where the 1234ze(E) refrigerant can separate from the oil.
• the heated mixture is removed from the heat exchanger and introduced to a separator whereby the refrigerant separates substantially in a vapor state from the oil that remains substantially in a liquid state.
• the oil is then returned through an oil valve where its pressure is decreased to match the starting pressure. From the valve the oil is returned to the mixer where it is again mixed with the refrigerant to repeat the process.
• the refrigerant vapor is passed to a condenser so as to liquefy it.
• the liquid is passed to an expansion valve, throttling the liquid refrigerant to cool the refrigerant.
• the cooled, throttled refrigerant can be liquid, vapor or a combination depending on the operator's choice.
• the cooled refrigerant is passed through the evaporator whereby the cooling ability of the refrigerant is utilized to cool a material (water or air) that is in a heat-exchanging relationship with the evaporator.
• the refrigerant is then returned from the evaporator to the mixer where it is again mixed with the oil to repeat the process again.
• composition of stream entering the separator is 90 wt % oil and 10 wt %
• Example 2 The data from Example 2 was used to develop a double effect absorption cycle.
• a Ford Motorcraft polypropylene glycol dimethyl ether-based oil is mixed with a liquid 1234ze(E) refrigerant in a closed mixer.
• the mixture is passed to a first absorber where the gaseous 1234ze(E) dissolves into the oil.
• the mixture is then passed to first pump that pressurizes the mixture and passes the mixture to a first heat exchanger/boiler.
• heat is exchanged with the mixture.
• the source of that heat can be thermal heat from solar collector external to the heat exchanger.
• the temperature of the mixture is raised.
• the heated mixture is removed from the heat exchanger and introduced to a second mixer where it is mixed with oil.
• the mixture from the second mixer is then introduced to a second absorber to ensure that all of the 1234ze(E) is dissolved in the oil.
• the mixture is drawn to a second pump that pumps the mixture to a second boiler where the temperature of the mixture is raised to a temperature where the 1234ze(E) refrigerant can separate from the oil.
• a source of heat to the boiler again, is provided to accomplish this, which source can be a thermal heat source derived from a solar collector.
• the mixture is taken from the second boiler to a separator whereby the refrigerant separates substantially in a vapor state from the oil that remains substantially in a liquid state.
• the oil is then returned to a tee where it is split sending a portion of the oil through a second oil valve and to the second mixer and the remaining portion of the oil to a first oil valve where the pressure is decreased to match the starting pressure.
• the oil then passes to the first mixer where it is again mixed with the refrigerant to repeat the process.
• the refrigerant vapor is passed to a condenser so as to liquefy it.
• the liquid is passed through an expansion valve, throttling the liquid refrigerant to cool the
• the cooled, throttled refrigerant can be liquid, vapor or a combination depending on the operator' s choice.
• the cooled refrigerant is passed through an evaporator whereby the cooling ability of the refrigerant is utilized to cool a material (water or air) external of evaporator.
• the refrigerant is then returned from the evaporator to the first mixer where it is again mixed with the oil to repeat the process again.
• the overall composition of the stream entering the separator is 90 wt% oil and 10 wt% refrigerant.
• Example 5 The solubility data in Example 5 was used to develop a model single effect absorption cycle. More specifically, in the model system, the POE oil is mixed with a liquid 1234ze(E) refrigerant in a closed mixer (which can be a simple "T" joint connecting two or more lines). The mixture is passed to an absorber where the gaseous 1234ze(E) dissolves into the oil. The liquid mixture is passed to a pump that pressurizes the mixture and passes the mixture through to a heat exchanger/boiler. In the boiler, heat is exchanged with the mixture. The source of that heat can be thermal heat from a solar collector external to the heat exchanger. The temperature of the mixture is raised to a temperature where the 1234ze(E) refrigerant can separate from the oil.
• a closed mixer which can be a simple "T" joint connecting two or more lines.
• the mixture is passed to an absorber where the gaseous 1234ze(E) dissolves into the oil.
• the liquid mixture is passed to a pump that
• the heated mixture is then removed from the heat exchanger and introduced to a separator whereby the refrigerant separates substantially in a vapor state from the oil that remains substantially in a liquid state.
• the oil is then returned through an oil valve where its pressure is decreased to match the starting pressure. From the valve the oil is returned to the mixer where it is again mixed with the refrigerant to repeat the process.
• the refrigerant vapor is passed to a condenser so as to liquefy it.
• the liquid is passed through an expansion valve, throttling the liquid refrigerant to cool the refrigerant.
• the cooled, throttled refrigerant can be liquid, vapor or a combination depending on the operator's choice.
• the cooled refrigerant is passed through an evaporator whereby the cooling ability of the refrigerant is utilized to cool a material (water or air) that is in a heat-exchanging relationship with the evaporator.
• the refrigerant is then returned from the evaporator to the mixer where it is again mixed with the oil to repeat the process again.
• composition of stream entering the separator is 90 wt % oil and 10 wt %
• Example 5 The solubility data in Example 5 was used to develop a model double effect absorption cycle. More specifically, in the model system mineral oil is mixed with a liquid 1234ze(E) refrigerant in a closed mixer. The mixture is passed to a first absorber where the gaseous
• 1234ze(E) dissolves into the oil.
• the mixture is then passed to a first pump that pressurizes the mixture and passes the mixture through to a first heat exchanger/boiler.
• heat is exchanged with the mixture.
• the source of that heat can be thermal heat from a solar collector external to the heat exchanger.
• the temperature of the mixture is raised.
• the heated mixture is removed from the heat exchanger and introduced to a second mixer where it is mixed with oil.
• the mixture from the second mixer is introduced to a second absorber to ensure that all of the 1234ze(E) is dissolved in the oil.
• the mixture is drawn to a second pump that pumps the mixture to a second boiler where the temperature of the mixture is raised to a temperature where the 1234ze(E) refrigerant can separate from the oil.
• a source of heat to the second boiler is provided to accomplish this, which can be thermal heat from a solar collector.
• the mixture is taken from the second boiler to a separator whereby the refrigerant separates substantially in a vapor state from the oil that remains substantially in a liquid state.
• the oil is then returned to a tee where it is split.
• a portion is sent through a second oil valve and to the second mixer.
• the remaining portion is sent through a first oil valve where the pressure is decreased to match the starting pressure.
• the oil then passes to the first mixer where it is again mixed with the refrigerant to repeat the process.
• the refrigerant vapor is passed to a condenser so as to liquefy it.
• the liquid is passed through an expansion valve, throttling the liquid refrigerant to cool the refrigerant.
• the cooled, throttled refrigerant can be liquid, vapor or a combination depending on the operator's choice.
• the cooled refrigerant is passed through an evaporator whereby the cooling ability of the refrigerant is utilized to cool a material (water or air) external of the evaporator.
• the refrigerant is then returned from the evaporator to the first mixer where it is again mixed with the oil to repeat the process again.
• Tee splits the flow 30% of the stream to the intermediate stage absorber and 70% to the low stage absorber. 8)
• the overall composition of the stream entering the separator is 90 wt% oil and 10 wt% refrigerant.
• Example 8 The solubility data of Example 8 was used to develop a model single effect absorption cycle. More specifically, in the model system, mineral oil is mixed with a liquid 1233zd(E) refrigerant in a closed mixer (which can be a simple "T" joint connecting two or more lines). The mixture in passes to an absorber where the gaseous 1233zd(E) dissolves into the oil. The liquid mixture is passed through to a pump that pressurizes the mixture and passes the mixture to a heat exchanger/boiler. In the boiler, heat is exchanged with the mixture. The source of that heat can be thermal heat from a solar collector external to the heat exchanger. The temperature of the mixture is raised to a temperature where the 1233zd(E) refrigerant can separate from the oil.
• a closed mixer which can be a simple "T" joint connecting two or more lines.
• the mixture in passes to an absorber where the gaseous 1233zd(E) dissolves into the oil.
• the liquid mixture is passed through to
• the heated mixture is removed from the heat exchanger and introduced to a separator whereby the refrigerant separates substantially in a vapor state from the oil that remains substantially in a liquid state.
• the oil is then returned to an oil valve where its pressure is decreased to match the starting pressure. From the valve, the oil is returned to the mixer where it is again mixed with the refrigerant to repeat the process.
• the refrigerant vapor is passed to a condenser so as to liquefy it.
• the liquid is passed through an expansion valve, throttling the liquid refrigerant to cool the refrigerant.
• the cooled, throttled refrigerant can be liquid, vapor or a combination depending on the operator's choice.
• the cooled refrigerant is passed through an evaporator whereby the cooling ability of the refrigerant is utilized to cool a material (water or air) that is in a heat-exchanging relationship with the evaporator.
• the refrigerant is then returned from the evaporator to the mixer where it is again mixed with the oil to repeat the process again.
• composition of stream entering the separator is 90 wt % oil and 10 wt %
• Example 8 The solubility data from Example 8 was used to develop a model double effect absorption cycle. More specifically, in the model system mineral oil is mixed with a liquid 1233zd(E) refrigerant in a closed mixer. The mixture is passed to a first absorber where the gaseous
• 1233zd(E) dissolves into the oil.
• the mixture is then passed to a first pump that pressurizes the mixture and passes it to a first heat exchanger/boiler.
• heat is exchanged with the mixture.
• the source of that heat can be thermal heat from a solar collector external to the heat exchanger.
• the temperature of the mixture is raised.
• the heated mixture is then removed from the heat exchanger and introduced to a second mixer where it is mixed with oil.
• the mixture from the second mixer is then introduced to a second absorber to ensure that all of the 1233zd(E) is dissolved in the oil.
• the mixture is taken from the second boiler to a separator whereby the refrigerant separates substantially in a vapor state from the oil that remains substantially in a liquid state.
• the oil is then returned to a tee where it is split.
• a portion of the oil is sent to a second oil valve and to the second mixer.
• the remaining portion of the oil is sent to a first oil valve where the pressure is decreased to match the starting pressure.
• the oil then passes to the first mixer where it is again mixed with the refrigerant to repeat the process.
• the refrigerant vapor is passed to a condenser so as to liquefy it.
• the liquid is then passed through an expansion valve, throttling the liquid refrigerant to cool the refrigerant.
• the cooled, throttled refrigerant can be liquid, vapor or a combination depending on the operator's choice.
• the cooled refrigerant is then passed through an evaporator whereby the cooling ability of the refrigerant is utilized to cool a material (water or air) external of the evaporator.
• the refrigerant is then returned from the evaporator to the first mixer where it is again mixed with the oil to repeat the process.
• the overall composition of the stream entering the separator is 90 wt% oil and 10 wt% refrigerant.
• solubility of refrigerant in the absorber is important to the overall performance of many important embodiments of the refrigeration cycle of the present invention. More specifically, higher concentrations of absorbed refrigerant tend to increase cycle COP by decreasing the boiler/generator load, both in reducing the mixture's boiling point as well as reducing the amount of heat needed to reach said boiling point. Additionally, pressure is an important parameter in determining both the absorber solubility and the evaporator temperature, and accordingly higher solubilities tend to reduce the required low side pressure allowing for more flexibility in the evaporator operating conditions. Solubility data was determined for both HFO-1234ze(E) and HFO-1234yf in different grades of POE oil at temperatures and pressures that are important for many absorbtion refrigeration cycles in accordance with the present, and this data are reported below.
• An absorption refrigeration system as disclosed in Figure 4 is used.
• POE oil of ISO 10 is mixed with a liquid 1234ze(E) refrigerant in a closed mixer and utilized according to the conditions and operating parameters described in Example 3 . Effective absorption refrigeration is achieved.
• Example 20 A mulit-stage absorption refrigeration system as disclosed in Figure 5 is used. POE oil of ISO 68 is mixed with a liquid 1234ze(E) refrigerant in a closed mixer and utilized according to the conditions and operating parameters described in Example 6. Effective absorption refrigeration is achieved.
• a mulit-stage absorption refrigeration system as disclosed in Figure 5 is used.
• POE oil of ISO 10 is mixed with a liquid 1234yf refrigerant in a closed mixer and utilized according to the conditions and operating parameters described in Example 6. Effective absorption refrigeration is achieved.
• a mulit-stage absorption refrigeration system as disclosed in Figure 5 is used.
• POE oil of ISO 32 is mixed with a liquid 1234yf refrigerant in a closed mixer and utilized according to the conditions and operating parameters described in Example 6. Effective absorption refrigeration is achieved.
• a absorption refrigeration system as disclosed in Figure 5 is used.
• POE oil of ISO 68 is mixed with a liquid 1234yf refrigerant in a closed mixer and utilized according to the conditions and operating parameters described in Example 2. Effective absorption refrigeration is achieved.
• transl233zd appreciably dissolves in each of alkylbenzene, silicone, and mineral oil, with alkylbenzene oil having the solubility advantage especially at temperatures closer to 30°C.
• non-limiting preferred embodiments for the absorption cycle would include transl233zd and in any of alkylbenzene, silicone, or mineral oil, more preferably transl233zd with alkylbenzene oil at absorber temperatures less than 50°C, preferably at temperatures of from about 0°C to about 30°C, preferably at temperatures of from about 10°C to about 30°C.
• a multi-stage absorption refrigeration system as disclosed in Figure 5 is used.
• Alkylbenzene oil is mixed with a liquid 1233zd(E) refrigerant in a closed mixer and utilized according to the conditions and operating parameters described in Example 6 . Effective absorption refrigeration is achieved.

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• 2016
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