JP5864533B2 - Absorption refrigeration cycle using LGWP refrigerant - Google Patents

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application relates to US Provisional Application Serial No. 61 / 320,305 filed April 1, 2010, and claims the benefit of its priority, the contents of which are incorporated herein by reference. .

  This application is also a continuation-in-part of US application serial number 12 / 432,466, filed April 29, 2009, which is US provisional application serial number 61/049, filed April 30, 2008. , 069, the contents of each of which are incorporated herein by reference.

  The present invention relates to an economical absorption refrigeration system using a refrigerant having a low global warming potential (GWP) and a low ozone depletion potential (ODP).

  Absorption refrigeration is a more economical alternative to compression refrigeration when waste heat or other low-cost heat (eg, solar heating) is available. Thus, absorption refrigeration has the potential to play a very important role in reducing the environmental impact of cooling systems operating in high temperature environments.

  Both absorption refrigerators and vapor compression refrigerators use refrigerants with very low boiling points. In both types, when this refrigerant evaporates or boils it takes away some heat with it and provides a cooling action. However, absorption refrigeration and vapor compression refrigeration differ in the manner in which the refrigerant changes from gas to return to liquid so that the cycle can be repeated. Vapor compression refrigerators often use mechanical work supplied by an electric compressor to increase the pressure on the gas and then condense the hot high pressure gas by heat exchange with a cold fluid (usually air). Return to liquid. Absorption refrigerators do not use mechanical work to increase the pressure of the gas, but change the gas back to liquid using different methods that require only a low power pump or, in some cases, only heat, thereby A system with fewer moving parts is provided, which increases the overall life of the system.

  Residential and commercial buildings are large consumers of energy and are the main consumers of electricity with a constantly changing demand. During periods of low to moderate demand, electricity is produced by the most efficient equipment that uses nuclear, coal, or hydroelectric energy sources because it is operating almost continuously. . However, during peak demand, less expensive and less efficient equipment, typically powered by natural gas or fuel oil, is used, which means fuel safety when using oil, Raises concerns about price stability. Peak demand also sets the overall size of the electrical system, including power generation and distribution systems. In addition, reducing demand when the power generation or transmission system is at their limits, increases the reliability of the electricity supply and is an effective way to avoid power outages that can have a significant negative economic impact It is.

  Solar energy can be utilized through the use of a relatively inexpensive collector panel, which is transferred to a working fluid that is typically water containing glycols added to reduce the freezing point. This fluid then becomes a heat source, which moves the absorption cooling system. In addition, it can be used to heat drinking water when cooling is not required. An additional benefit with new installations is that the basic vapor compression cooling system can be miniaturized, thereby allowing it to operate with fewer cycling, which would improve the performance of this system. That is. Absorption refrigeration also has advantages in such environments because it typically has the ability to provide the necessary cooling using the same source of energy that increases the load on these systems, i.e. solar energy. Can do.

  Common examples of refrigeration cycles are food freezers and freezers and air conditioners. Reversible cycle heat pumps to provide thermal comfort also operate by taking advantage of the physical properties of refrigerant evaporation and condensation. In heating, ventilation, and cooling (HVAC) applications, a heat pump usually refers to a refrigeration system that includes a reversal valve and an optimized heat exchanger that can reverse the direction of heat flow. Most commonly, during that heating cycle, the heat pump draws heat from the air, from the ground, or even from water.

While absorption systems have been limited in use for many years, applicants have recognized that conventional working fluids have had significant drawbacks that limit their success. For example, two of the most common absorption refrigeration pair NH ₃ - are water and water -LiBr. NH ₃ -water uses NH ₃ as a refrigerant and water as an absorbent. While NH ₃ functions well as a refrigerant in many applications, the toxicity of NH ₃ limits its use in places where it can be occupied by the public. In addition, the general can be used in combination with the copper, one of the construction materials problem than in the cooling system, NH 3 that the installed _- the cost of systems based on water, more unwanted and / or more expensive Can be increased by having to use different materials. With water-LiBr, problems arise because water is not a suitable refrigerant in many important interesting cases. Applicants have come to understand that water has two major drawbacks that limit its viability in certain important applications. First, the low pressure makes the equipment size impractical for many applications. Second, because of the freezing point of water, it cannot be used at temperatures below 0 ° C. As a result, due to problems such as toxicity and / or flammability and / or corrosivity and / or equipment costs, such systems typically require only very small changes in the industrial setting or refrigerant. Used only for low-capacity applications (low-capacity systems, ie some refrigerators in hotels and RVs, but even these have largely disappeared due to the toxicity of NH ₃ ).

  Accordingly, applicants have recognized the continuing need for safer and environmentally friendly refrigerants for absorption refrigeration systems. Applicants may benefit from a system that can provide an effective and environmentally acceptable fluid for use in a variety of applications from industrial heat recovery to residential solar assisted refrigeration Also came to recognize.

  Applicants include fluorinated organic compounds having from 1 to 8 carbon atoms (C1-C8) and in certain embodiments fluorinated organic compounds including specific hydrofluoroolefins and / or hydrochlorofluoroolefin compounds. It has been found that certain refrigerant / absorbent pairs are well suited for use in absorption refrigeration and have special advantages. In certain embodiments, fluorinated organic compounds according to the present invention, in particular, but not exclusively, certain hydrofluoroolefins and / or hydrochlorofluoroolefin compounds, and / or C2-C4 hydrofluoroolefins and / or hydrochloro Fluoroolefin compounds are utilized as refrigerants, and the absorbent portion is either a fluorinated organic compound and / or a non-fluorinated oil. Hydrofluoroolefins such as HFO-1234yf (eg 1,1,1,2-tetrafluoropropene) and HFO-1234ze (E) (eg 1,1,1,3-tetrafluoropropene) (but not limited to) Have been found to have excellent refrigeration capacity and very short atmospheric lifetimes that make them environmentally friendly and are preferred for use according to the present invention, preferably as refrigerants. Hydrochlorofluoroolefins, especially monochlorotrifluorpropenes such as HCFO-1233zd (1-chloro-3,3,3-trifluoropropene) (but not limited to) also make excellent refrigeration capacity and make them environmentally friendly It has been found to have a very short atmospheric lifetime and is preferred for use according to the present invention, preferably as an absorbent. These refrigerants also have the added benefit of being able to be used with copper and aluminum. Both the use of copper and aluminum increases efficiency through improved heat transfer and reduces overall costs.

  In certain embodiments, the absorption refrigeration fluid of the present invention acts as an absorbent, a first fluorinated organic compound having a relatively high boiling point, and as a refrigerant, a second fluorinated organic compound having a relatively low boiling point including. In a particular example, the absorbent comprising the first fluorinated organic compound has a boiling point that is at least 40 ° C. higher than the boiling point of the solute comprising the second fluorinated organic compound. In a further embodiment, the absorbent compound is a nonionic compound and has a total number of carbon / oxygen atoms that is at least 2 (2) greater than the total number of carbon / oxygen atoms in the refrigerant. Thus, in embodiments where the refrigerant includes one or more C1-C4 fluorinated compounds, or one or more C2-C4 hydrofluoroolefins and / or hydrochlorofluoroolefin compounds, the absorbent compound is one or more C2 -C8 fluorinated compounds, in certain embodiments, comprising one or more C3-C8 hydrofluoroolefin and / or hydrochlorofluoroolefin compounds.

In accordance with certain aspects of such embodiments, the absorbent portion of the fluid is selected from the group consisting of fluoroethers, fluoroketones, HFCs, HFOs (including HFCOs), and combinations thereof. The refrigerant portion of the pair is selected from the group consisting of HFCs, HFOs (including HFCOs), CO ₂ and combinations thereof. A non-limiting example of a fluoroether for use as an absorbent according to the present invention is methyl nonafluorobutyl ether. A non-limiting example of a fluoroketone for use as an absorbent according to the present invention is perfluoro (2-methyl-3-pentanone). A non-limiting example of HFC for use as an absorbent according to the present invention is HFC-245fa (eg, 1,1,1,3,3-pentafluoropropane). A non-limiting example of HFO for use as an absorbing solvent according to the present invention is HFO-1233zd, including HFO-1233zd (E). A non-limiting example of HFO for use as a refrigerant according to the present invention is HFO-1234yf. A non-limiting example of HFC for use as a refrigerant according to the present invention is HFC-32 (difluoromethane). Particularly preferred according to the invention are, but not exclusively, the refrigerant / absorbent pairs HFC32 / HFC-245fa, HFC-32 / HFO1234yf, HFC-32 / 1233zd (E) and HFO-1234yf / 1233zd (E). Yes, most preferably, but not exclusively, is the use of such a pair in conjunction with an absorption refrigeration system that includes energy input in the form of solar power, and even more preferably, but not exclusively, The use of such solar power energy input to reduce the peak demand of commercial systems.

In certain other embodiments, the pair of refrigerant portions according to the present invention is selected from among specific hydrofluoroolefins and / or hydrochlorofluoroolefin compounds, and the absorbent and / or solvent portions are non-fluorinated oils. Or non-fluorinated oils, which may be selected from organic oils such as polyalkylene glycol oils, polyalphaolefin oils, mineral oils, and polyol ester oils (including combinations thereof). It has been discovered that these refrigerant and oil solutions allow the refrigerant to be used as a working fluid in an absorption refrigeration system. Many of these refrigerants are characterized by having low GWP (ie less than 1000 or less than 100 compared to CO ₂ ), low or no appreciable ozone depletion potential, non-toxic and non-flammable is there. One skilled in the art will appreciate that in one aspect, the invention includes a combination of the refrigerant, fluorinated absorbent and non-fluorinated oil.

  Accordingly, one aspect of the present invention includes a method for providing refrigeration comprising: (a) a first liquid phase refrigerant comprising one or more fluorinated organic compounds having from 1 to 8 carbon atoms. The stream is evaporated to produce a low pressure gas phase refrigerant stream wherein the evaporation transfers heat from the system to cool; (b) the low pressure gas phase refrigerant stream is carbon / oxygen atoms in the refrigerant A first liquid phase solvent stream comprising one or more organic compounds having a total number of carbon / oxygen atoms that is at least 2 (2) greater than the total number of the first and substantially all of the refrigerant in the gas phase refrigerant stream. Contacting under conditions effective to dissolve in the solvent of the liquid phase solvent stream to produce a refrigerant-solvent solution stream; (c) increasing the pressure and temperature of the refrigerant-solvent solution stream; (d) The refrigerant-solvent solution stream is thermodynamically separated to produce a high pressure gas phase refrigerant stream and a second liquid phase. (E) recirculating the second liquid phase solvent stream to step (b) to produce the first liquid phase solvent stream; (f) condensing the high pressure gas phase refrigerant stream. A second liquid phase refrigerant stream; and (g) recirculating the second liquid phase refrigerant stream to step (a) to produce the first liquid phase refrigerant stream.

  As used herein, the terms “low pressure gas phase refrigerant” and “high pressure gas phase refrigerant” are relative to each other. That is, the low pressure gas phase refrigerant has a pressure above 0 psia but lower than the pressure of the high pressure gas phase refrigerant. Similarly, a high pressure gas phase refrigerant has a pressure below the critical point of the composition but higher than the pressure of the low pressure gas phase refrigerant.

As used herein, the term “substantially all” with respect to a composition means at least about 90 weight percent, based on the total weight of the composition.
In another aspect, the present invention provides an absorption refrigeration system comprising:
(A) a refrigerant selected from the group consisting of one or more fluorinated organic compounds; (b) 1 to 8 carbon atoms (C1-C8) having a boiling point at least 40 ° C. higher than the boiling point of the refrigerant; An absorbent containing one or more fluorinated organic compounds; (c) an evaporator suitable for evaporating the refrigerant; (d) a mixer suitable for mixing the refrigerant with the absorbent; Wherein the mixer is fluidly connected to the evaporator; (e) an absorber suitable for dissolving at least a portion of the refrigerant in the absorbent to form a solution; Wherein said absorber is fluidly connected to said mixer; (f) a pump fluidly connected to said absorber; (g) heat exchange fluidly connected to said pump. (H) steam cooling the above solution A separation device suitable for thermodynamic separation into a component and a liquid absorbent component, wherein said separation device is fluidly connected to said heat exchanger; (i) said separation device And a return oil line fluidly connected to the mixer, and (j) a condensing device suitable for condensing the vapor refrigerant component, wherein the condensing device comprises the separation device and the evaporation It is fluidly connected to the device.

This invention is an environmentally friendly and economical refrigeration process.
In certain embodiments, the methods and systems are powered at least in part by solar energy to provide cooling when the load is highest. The absorbing refrigerant has low global warming potential, can be used safely, and has high energy efficiency.

FIG. 1 is a graphical representation of data showing the solubility of HFO-1234ze (E) in a PAG lubricant. FIG. 2 is a schematic diagram of an absorption refrigeration cycle according to one embodiment of the present invention. FIG. 3 is a schematic diagram of another absorption refrigeration cycle according to another embodiment of the present invention. FIG. 4 is a schematic view of one embodiment of the absorption compression system (B) and the vapor compression system (A). FIG. 5 is a graphical representation of data showing the GWP impact on Life Cycle Climate Performance (LCCP). FIG. 6 is a graphical representation of data showing the GWP impact on LCCP including the impact of reduced efficiency.

  Both the absorption system and the vapor compression system are Carnots that transfer thermal energy from a cold reservoir (cooling load) to a hot reservoir (ambient) by using thermal energy Qin, or axial work Wsh or mechanical vapor compression with respect to absorption technology. Operates with an idealized energy conversion cycle. The illustration of FIG. 4 provides a simplified diagram of each generalized version of such a system. As can be seen from these drawings, both the absorption and vapor compression systems utilize a condensing device for exchanging heat with the surroundings, an expansion device, and an evaporation device for cooling the system. The main difference is that the absorption system utilizes thermal energy to act as a “thermal” or “chemical” compressor through the use of a chemical potential between the refrigerant and the absorbent, while vapor compression systems are often electrically It is to use a mechanical compressor that draws the shaft power that is the target. Applicants have found an efficient absorption system by identifying appropriate refrigerant-absorbent pairs that efficiently compress the refrigerant. In many embodiments, the only moving part in the absorption system is a pump, which provides a long life for the entire system.

  In certain embodiments of the present invention, fluorinated organic compounds having from 1 to 8 carbon atoms (C1-C8) and in certain embodiments include certain hydrofluoroolefins and / or hydrochlorofluoroolefin compounds. Certain refrigerant / absorbent pairs containing organic compounds are well suited for use in absorption refrigeration and have certain advantages. In certain embodiments, fluorinated organic compounds according to the present invention, in particular, but not exclusively, certain hydrofluoroolefins and / or hydrochlorofluoroolefin compounds, and / or C2-C4 hydrofluoroolefins and / or hydrochloro Fluoroolefin compounds are utilized as refrigerants, and the absorbent portion is either a fluorinated organic compound or a non-fluorinated oil. Hydrofluoroolefins such as HFO-1234yf (eg 1,1,1,2-tetrafluoropropene) and HFO-1234ze (E) (eg 1,1,1,3-tetrafluoropropene) (but not limited to) Have been found to have excellent refrigeration capacity and very short atmospheric lifetimes that make them environmentally friendly and are preferred for use according to the present invention, preferably as refrigerants. Hydrochlorofluoroolefins, especially monochlorotrifluorpropenes such as HCFO-1233zd (1-chloro-3,3,3-trifluoropropene) (but not limited to) also make excellent refrigeration capacity and make them environmentally friendly It has been found to have a very short atmospheric lifetime and is preferred for use according to the present invention, preferably as an absorbent. These refrigerants also have the added benefit of being able to be used with copper and aluminum. Both the use of copper and aluminum increases efficiency through improved heat transfer and reduces overall costs.

  In certain embodiments, the absorption refrigeration fluid of the present invention acts as an absorbent, a first fluorinated organic compound having a relatively high boiling point, and as a refrigerant, a second fluorinated organic compound having a relatively low boiling point including. In certain cases, the absorbent containing the first fluorinated organic compound has a boiling point that is at least 40 ° C. higher than the boiling point of the solute containing the second fluorinated organic compound. In a further embodiment, the absorbent compound is a nonionic compound and has a total number of carbon / oxygen atoms that is at least 2 (2) greater than the total number of carbon / oxygen atoms in the refrigerant. Thus, in embodiments where the refrigerant includes one or more C1-C4 fluorinated compounds, or one or more C2-C4 hydrofluoroolefins and / or hydrochlorofluoroolefin compounds, the absorbent compound is one or more C2 -C8 fluorinated compounds, in certain embodiments, comprising one or more C3-C8 hydrofluoroolefin and / or hydrochlorofluoroolefin compounds.

In accordance with certain aspects of such embodiments, the absorbent portion of the fluid is selected from the group consisting of fluoroethers, fluoroketones, HFCs, HFOs (including HFCOs), and combinations thereof. The refrigerant portion of the pair is selected from the group consisting of HFCs, HFOs (including HFCOs), CO ₂ and combinations thereof. A non-limiting example of a fluoroether for use as a solvent according to the present invention is methyl nonafluorobutyl ether. A non-limiting example of a fluoroketone for use as an absorbent according to the present invention is perfluoro (2-methyl-3-pentanone). A non-limiting example of HFC for use as an absorbent according to the present invention is HFC-245fa (eg, 1,1,1,3,3-pentafluoropropane). A non-limiting example of HFO for use as an absorbing solvent according to the present invention is HFO-1233zd, including HFO-1233zd (E). A non-limiting example of HFO for use as a refrigerant according to the present invention is HFO-1234yf. A non-limiting example of HFC for use as a refrigerant according to the present invention is HFC-32 (difluoromethane). Particularly preferred according to the invention are, but not exclusively, the pairs HFC32 / HFC-245fa, HFC-32 / HFO1234yf, HFC-32 / 1233zd (E) and HFO-1234yf / 1233zd (E), most preferred Is the use of such a pair in conjunction with an absorption refrigeration system that includes, but not exclusively, energy input in the form of solar power, and even more preferably, but not exclusively, a commercial system Is the use of such solar power energy input to reduce the peak demand.

Refrigerant for the present invention is not limited to the embodiments of the hydro fluoroolefins and hydrochlorothiazide fluoroolefins of formula C _w H _x F _y Cl _z is also included, where w is an integer from 3 to 5 X is an integer from 1 to 3, and z is an integer from 0 to 1, where y = (2 · w) −x−z. Specific refrigerants include tetrahalopropenes such as tetrafluoropropenes and mono-chloro-trifluoropropenes, or tetrahalopropenes having a —CF ₃ moiety such as 1,1,1,2-tetrafluoropropene. 1,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene (all their stereoisomers such as trans-1,3,3,3-tetrafluoropropene, Cis-1,3,3,3-tetrafluoropropene, trans-1-chloro-3,3,3-trifluoropropene, cis-1-chloro-3,3,3-trifluoropropene) and Hydrohalopropenes including 3,3,3-trifluoropropene are included. Certain useful refrigerants also include two or more hydrofluoroolefins, mixtures of hydrochlorofluoroolefins, and mixtures of both hydrofluoroolefins and hydrochlorofluoroolefins.

  In a particular embodiment of the present invention, hydrofluoroolefin and / or hydrochlorofluoroolefin refrigerant is used as a working fluid in an absorption refrigeration system, ie, a fluid that changes state from gas to liquid or vice versa by a thermodynamic cycle. This phase change is facilitated by dissolving the gas phase refrigerant in an oil solvent (as an absorbent with the additional absorbent provided herein) to form a solution. Preferably, but not exclusively, a pump and heat exchanger are used to efficiently increase the pressure and temperature of the solution, respectively. The pressurized and heated solution is then flushed to produce high pressure refrigerant vapor. The high pressure steam is then passed through a condenser and evaporator to transfer heat from the system and cool.

  Solvents useful in the present invention may be selected from the group consisting of polyalkylene glycol oils, polyalphaolefin oils, mineral oils and polyol ester oils. The oil chosen is generally thermally stable, has a very low vapor pressure, is non-toxic and non-corrosive. Specific oils that meet these criteria and can be used with the various olefins described above are polyethylene glycol oils, polyol ester oils, oils based on polypropylene glycol dimethyl ether and mineral oils. Such oils can also act in absorption capacity, either alone or in combination with one or more of the fluorinated adsorbents discussed herein, as discussed herein. For this purpose, the discussion herein regarding the mixing of a refrigerant and solvent is equally applicable to a solution containing that refrigerant, fluorinated adsorbent and solvent.

  In certain embodiments, the refrigerant and solvent are mixed at a rate and under conditions effective to form a solution of the refrigerant dissolved in the solvent. Preferably, but not exclusively, the refrigerant and solvent mixture is at a substantial proportion of the refrigerant mixed with the solvent, or at a rate at which substantially all is dissolved in the solvent. That is, in certain embodiments, 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 its saturation point reduces the likelihood that vapor refrigerant can reach the pump and cause cavitation.

  The refrigerant and solvent may be mixed by a mixer. Such mixers include, but are not limited to, static mixers and suction devices (ie, venturi pumps). In certain embodiments, the mixer is a simple junction of two transfer lines (eg, pipes, tubes, hoses, and the like) that generate turbulence, eg, a T fitting.

Dissolution of the low pressure gas phase refrigerant in the oil solvent may occur at a refrigerant temperature of about -10C to about 30C, or about 0C to about 10C.
Dissolution of the refrigerant in the solvent may occur in the absorber, at least to a large extent. The absorber can be of any type suitable for dissolving the refrigerant gas in an oil based solvent. Examples of absorption devices include heat exchangers through which a cooling medium circulates or around.

  A solution containing the refrigerant and solvent is pumped against the 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 vapor refrigerant compression using a compressor. In addition to consuming less energy, pumps are typically less expensive to install and maintain compared to compressors. This energy and cost saving is a distinct advantage of the present invention over conventional compression refrigeration systems.

  The solution is also heated after being pressurized in certain embodiments. Heating may be accomplished using heat exchangers, such as tube heat exchangers and flat plate heat exchangers or distillation columns. In certain embodiments, the heating of the solution is performed by a waste heat recovery unit (WHRU) (ie, a hot gas or liquid stream, such as exhaust gas from a gas turbine, heat generated in a solar collector, or a power plant or refinery A heat exchanger that recovers heat from, but not limited to, waste gas. The WHRU working medium may include either water—pure water or water including triethylene glycol (TEG) —thermal oil or other medium that aids in heat transfer. In other embodiments, heating the solution comprises direct heating from geothermal, solar derived heat or combustion of a fuel such as propane.

  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. Examples of such thermodynamic separation processes include column distillation and flushing. Since the two fractions are in different phases, they can be easily separated.

  In certain embodiments, the liquid solvent phase is recycled back to the mixer, while the gas phase containing the refrigerant is transferred to a condensing device where at least some or substantially all of the refrigerant is in its vapor phase. Converted from phase to liquid phase.

  The type of condenser useful in the present invention is not particularly limited as long as they are suitable for condensing hydrofluoroolefin or hydrochlorofluoroolefin refrigerants. Examples of condensers include horizontal or vertical in-shell condensers and horizontal or vertical in-tube condensers.

  The liquid phase refrigerant is passed through an expansion valve to reduce the refrigerant pressure and correspondingly cool the refrigerant. The cooled and throttled refrigerant can be a liquid phase, a gas phase, or a mixed phase.

  The refrigerant is then passed through an evaporator, where heat is extracted (ie, frozen) from the system to be cooled using the cooling capacity of the refrigerant during evaporation. Preferably, but not exclusively, the material to be cooled in the system is water with or without a heat transfer additive such as PEG, for example as cold water, a distribution system for air conditioning Can be circulated to air handlers. However, the material to be cooled can also be air used for direct air conditioning. In addition, the external material can be any flowable material that needs to be cooled, and if it is water or air, the cooled material can be used for purposes other than air conditioning (eg food or other products). Can be used for cooling).

  The type of evaporator used to evaporate the liquid phase refrigerant is not particularly limited as long as it is suitable for evaporating the hydrofluoroolefin or hydrochlorofluoroolefin refrigerant. Examples of useful evaporators include forced circulation evaporators, natural circulation evaporators, long and short tube vertical evaporators, falling thin film evaporators, horizontal tube evaporators, and flat plate evaporators. Is included.

  After evaporating the refrigerant, it typically becomes (but not exclusively) a low pressure gas phase refrigerant having a temperature of about 30 ° C. to about 60 ° C., and in certain embodiments about 40 ° C. to about 50 ° C. . The low pressure gas phase refrigerant is recirculated and returns to the mixer.

  The process of the present invention, in a particular embodiment, is a closed loop system in which both the refrigerant and solvent are recycled. Absorbent refrigerant forms according to this invention include single, double or triple effect absorption refrigeration processes. Single and double utility processes are described in the examples and figures described below.

  Considering non-ideal behavioral characteristics such as viscous friction (pressure drop), thermal mixing (energy exchange), mass mixing (absorption and desorption rates), the heat transfer action and basic control of the system are refrigerant and It can play an important role in the selection of other system parameters. In addition, the solubility and thermophysical properties of the working pair could be determined and considered in connection with the determination of the mixing and operating parameters. The mixing (thermal and mass) of the working fluid pair can also be important for the design of the absorber, which is often the most engineered component. The rate of absorption may also be important for determining and evaluating different refrigerant flow configurations and may require consideration of temporary system startup effects. In addition, the environmental effects on the refrigeration system take into account the direct contribution from fluid leakage (direct action of fluid GWP), the amount of energy it consumes (indirect action), and the manufacture of the device. May include an assessment of the amount of energy used to do (indirect) and the amount of energy used to dispose of the device (indirect). Limiting to only technologies with low direct action does not correctly solve the overall problem of energy use and our environmental impact. As described below, LCCP analysis can be used to evaluate choices in technology development. Working fluids should not only have a low overall fluid GWP, but they must also have a good social return due to energy independence and reduced energy consumption for technology development. To determine the environmental impact of refrigerant selection for this application, both direct and indirect contributions to global warming analysis were performed. The direct contribution comes from the release of the refrigerant, and the indirect contribution is due to the burning of fossil fuels to supply the power consumed by the facility.

To determine typical heat pump power consumption over the course of one year, averaged weather data for the average of 29 cities across the US data from the Air Conditioning Heating and Refrigeration Association Standard for Coolers (AHRI Std 550) The bin analysis was performed using the following weather conditions. Assumptions for this analysis include a value of 0.65 kg CO2 per kW-hr of electricity production for the United States, an end-of-life loss of 5% and an end-of-life loss of 15% A lifetime of years was included. The impact was determined by:
Direct = Refrigerant charge x (annual loss rate x life + loss due to end of life) x GWP
Indirect = annual power consumption x life x 0.65
This information was used to perform a life cycle climatic performance (LCCP) analysis, which is shown in FIGS. 5 and 6 herein. From these results, it is very clear that the indirect contributing factor overwhelms any contribution from refrigerant discharge. Any reduction below 400 levels has no significant effect on the whole.

  The following examples are given as specific illustrations of the invention. It should be noted, however, that the invention is not limited to the specific details set forth in the examples.

Example 1 :
Using a microbalance, the solubility of trans-1,3,3,3-tetrafluoropropene (1234ze (E)) in Ford motor craft oil (PAG refrigerant compressor oil satisfying Ford specification number WSH-M1C231-B) was used. Measured. Non-Random Two Liquid (“NRTL”) activity coefficient model (Renon H., Prausnitz JM, “Local composition in excess thermodynamic functions for liquid mixtures” AIChE J., 14 (1), S. The solubility measured with the correlation of the data using 135-144, 1968)) is shown in FIG. From these data, it can be seen that Ford Motor Craft oil has a nearly negligible vapor pressure and that the NRTL model can accurately represent the data.

Example 2 :
Using data from Example 1, a single effect absorption cycle was developed. A representative schematic of the single effect absorption system of the present invention is illustrated in FIG.

  In FIG. 2, oil based on Ford Motorcraft polypropylene glycol dimethyl ether from line 10 and liquid 1234ze (Z) refrigerant from line 4 and sealed mixer 20 (which is a simple “connecting lines 4 and 10 to line 5” In the T ″ junction). The mixture is sent through line 5 to the absorber 22 where the gaseous 1234ze (Z) dissolves in the oil. The liquid mixture is sent through line 6 to pump 24, which pressurizes the mixture and sends the mixture through line 7 to heat exchanger / boiler 26. In the boiler 26, heat is exchanged with the mixture. The source of heat can be waste heat from industrial operations (eg, power generation) external to the heat exchanger. The temperature of the mixture is raised to a temperature at which the 1234ze (Z) refrigerant can be separated from the oil. The heated mixture is moved from the heat exchanger through line 8 and introduced into the separation device 28, whereby the refrigerant is separated in a substantially vapor state from the oil that remains in a substantially liquid state. . The oil is then returned through line 9 and through oil valve 30 where its pressure is reduced to match the pressure in line 4. The oil from valve 30 is returned to mixer 20 through line 10 where it is again mixed with the refrigerant and the process is repeated.

  From the separator 28, the refrigerant vapor is sent to the condenser 32 through line 1 to liquefy it. The liquid is sent through the expansion valve 34 through the line 2, and the liquid refrigerant is decompressed to cool the refrigerant. The cooled and depressurized refrigerant can be a liquid, vapor or combination, depending on the operator's choice. The cooled refrigerant is allowed to pass through the evaporator 36, thereby cooling the substance (water or air) in a heat exchange relationship with the evaporator 36 using the cooling capacity of the refrigerant. The refrigerant is then returned from the evaporator 36 through line 4 to the mixer 20 where it is again mixed with the oil and the process is repeated again.

The input parameters for the single effect absorption cycle of FIG. 2 are as follows:
1) Evaporator 28: 2 ° C
2) Condenser 32: 40 ° C
3) Supply 3000 kJ / hr to boiler 26 4) Saturated liquid exits absorber 22 5) Superheat exiting its evaporator 36 through line 4: 3 ° C.
6) The composition of stream 8 is 90 wt% oil and 10 wt% refrigerant.

Using these parameters, the calculated coefficient of performance (“COP”) using 1234ze (Z) and Ford motor craft oil is 4.56.
Example 3 :
A representative schematic of dual effect absorption is illustrated in FIG.

  In FIG. 3, Ford Motorcraft polypropylene glycol dimethyl ether based oil from line 17 is mixed with liquid 1234ze (Z) refrigerant from line 4 in a sealed mixer 40. The mixture is sent through line 5 to the first absorber 42 where the gaseous 1234ze (Z) dissolves in the oil. The mixture is sent through line 6 to the first pump 44, which pressurizes the mixture and sends the mixture through line 7 to the first heat exchanger / boiler 46. In the boiler 46, heat is exchanged with the mixture. The source of heat can be waste heat from industrial operations (eg, power generation) external to the heat exchanger 46. Increase the temperature of the mixture. The heated mixture is removed from heat exchanger 46 through line 8 and introduced into second mixer 48 where it is mixed with the oil from line 15. The mixture from mixer 48 is removed through line 9 and introduced into second absorber 50 to ensure that all of its 1234ze (Z) has been dissolved in the oil. From the second absorber 50, the mixture is drawn through line 10 to the second pump 52, which pushes the mixture to the second boiler 54, where the temperature of the mixture is separated from the oil by the 1234ze (Z) refrigerant. Raise to a temperature that can. To accomplish this, a heat source is provided to the boiler 54, which can be of the type described above.

  The mixture is removed from the second boiler 54 and sent through line 12 to a separator 56, so that the refrigerant separates from the oil that remains substantially liquid in a substantially vapor state. The oil is then returned through line 13 to tee 58 where it is divided between lines 14 and 16. Line 14 sends oil through second oil valve 60 and through line 15 to second mixer 48. Line 16 sends oil through first oil valve 62 where its pressure is reduced to match the pressure in line 4. The oil is then sent through line 17 to mixer 40 where it is again mixed with the refrigerant and the process is repeated.

  From the separator 56, the refrigerant vapor is sent through line 1 to the condenser 64 to liquefy it. The liquid is sent through the expansion valve 66 through the line 2, and the liquid refrigerant is decompressed to cool the refrigerant. The cooled and depressurized refrigerant can be a liquid, vapor or combination, depending on the operator's choice. The cooled refrigerant is allowed to pass through the evaporator 68, thereby cooling the substance (water or air) outside the evaporator 68 using the cooling capacity of the refrigerant. The refrigerant is then returned from evaporator 68 through line 4 to mixer 40 where it is again mixed with the oil and the process is repeated again.

The input parameters for the dual effect absorption cycle of FIG. 3 are as follows:
1) Evaporator 68: 2 ° C
2) Condenser 64 40 ° C
3) The pressure leaving the pump 44 is

4) Supply 1500 kJ / hr to boiler 46 5) Saturated liquid exits both absorber 42 and absorber 50 6) Superheat exiting its evaporator 68: 3 ° C.
7) T-tube 58 splits its flow into 30% stream 14 and 70% stream 16.

8) The composition of stream 12 is 90 wt% oil and 10 wt% refrigerant.
Using these parameters, the calculated COP using 1234ze (Z) and Ford motor craft oil is 5.04.

  Those skilled in the art will recognize that there are other variations of the absorption refrigeration system disclosed above that can be implemented. For example, Perry's Chemical Engineers' Handbook; Green. DW; Perry, RH; McGraw-Hill (2008) pg 11-90-11-93 discloses another variation of an absorption refrigeration cycle that uses a different liquid than we use. However, many of these variations can be used in the practice of this invention in other ways.

In addition, various additives can be added to the refrigeration system of the present invention. For example, a stabilizer may be added to avoid polymerization while the olefin refrigerant is in use. Such stabilizers are known and include, for example, terpenes, epoxides and the like. Other optional additives for addition to the refrigerant include the following:
1. Antioxidants, eg those based on phenol, eg BHT
2. 2. Extreme pressure additives-chlorinated materials, phosphorus based materials-tricresyl phosphate, sulfur based materials Defoaming additive (for example, silicon)
4). Oily additives (eg organic acids and esters)
5. Acid scavengers (for example) epoxides.

Example 4
With particular reference to the diagram provided above, the efficiency of the absorption cycle is calculated as Qcooling / (Qin + WP). Even if Qin is considered waste heat and is a “free” source of energy, this is the best way to compare potential refrigerant pairs. A typical NH 3 -water absorption cycle operates at COP = about 0.5-0.6 at 5 ° C. evaporator temperature and 40 ° C. ambient temperature. One absorption refrigeration pair according to the present invention is HFO-1234yf and PAG oil. This particular absorption pair benefits from the fact that the PAG oil has a negligible vapor pressure and thus the separation in the generator is very simple. When operated at an evaporator temperature of 2 ° C. and an ambient temperature of 40 ° C., the COP for this cycle is about 0.6, which is almost the same as an ideal NH 3 -water COP.
The present invention includes the following aspects.
[1] The following:
a. A first liquid-phase refrigerant stream comprising one or more fluorinated organic compounds having from 1 to 8 carbon atoms is evaporated to produce a low-pressure gas-phase refrigerant stream, wherein said evaporation transfers heat from the system Let it cool;
b. The low-pressure gas-phase refrigerant stream comprises a first liquid-phase solvent stream comprising one or more organic compounds having a total number of carbon / oxygen atoms that is at least 2 greater than the total number of carbon / oxygen atoms in the refrigerant; Contacting substantially all of the refrigerant of the phase refrigerant stream under conditions effective to dissolve in the solvent of the first liquid phase solvent stream to produce a refrigerant-solvent solution stream;
c. Increasing the pressure and temperature of the refrigerant-solvent solution stream;
d. Thermodynamically separating the refrigerant-solvent solution stream into a high pressure gas phase refrigerant stream and a second liquid phase solvent stream;
e. Recirculating said second liquid phase solvent stream to step (b) to produce said first liquid phase solvent stream;
f. Condensing said high pressure gas phase refrigerant stream to produce a second liquid phase refrigerant stream; and
g. The second liquid phase refrigerant stream is recirculated to step (a) to produce the first liquid phase refrigerant stream.
A method for providing refrigeration, comprising:
[2] The one or more organic compounds in the first liquid phase solvent stream have a boiling point that is at least 40 ° C. higher than the boiling point of the one or more organic compounds in the first liquid phase refrigerant stream. The method according to [1].
[3] The method according to [1], wherein the one or more organic compounds in the first liquid-phase refrigerant stream are selected from the group consisting of HFCs, HFOs, HFCOs, CO2, and combinations thereof. .
[4] The one or more organic compounds in the first liquid phase refrigerant stream are 1,1,1,2-tetrafluoropropene, difluoromethane, trans-1,1,1,3-tetrafluoro. The method according to [3], which is selected from one or more of propene, cis-1,1,1,3-tetrafluoropropene, 3,3,3-trifluoropropene, and combinations thereof.
[5] The one or more organic compounds in the first liquid phase solvent stream are selected from the group consisting of fluoroethers, fluoroketones, HFC, HFOs, HFCOs, and combinations thereof. The method according to [1].
[6] The organic compound in the first liquid phase solvent stream is nonafluorobutyl ether, perfluoro (2-methyl-3-pentanone), 1,1,1,3,3-pentafluoropropane, 1-chloro- The method of [5], selected from the group consisting of 3,3,3-trifluoropropene, and combinations thereof.
[7] The one or more organic compounds in the first liquid phase refrigerant stream are 1,1,1,2-tetrafluoropropene, difluoromethane, trans-1,1,1,3-tetrafluoropropene. Selected from one or more of cis-1,1,1,3-tetrafluoropropene, 3,3,3-trifluoropropene, and combinations thereof, in the first liquid phase solvent stream Organic compounds of nonafluorobutyl ether, perfluoro (2-methyl-3-pentanone), 1,1,1,3,3-pentafluoropropane, 1-chloro-3,3,3-trifluoropropene, and their The method according to [1], which is selected from a group consisting of combinations.
[8] The organic compound of one or more of said first liquid refrigerant stream of the includes at least one compound having the formula _{C w H x F y Cl z} , where w is from 3 to 5 The method of [1], wherein x is an integer from 1 to 3, z is an integer from 0 to 1, and y = 2w-xz.
[9] The method of [1], wherein the solvent is selected from the group consisting of polyethylene glycol oil, polyol ester oil, oil based on polypropylene glycol dimethyl ether, and mineral oil.
[10] The following:
a. A refrigerant selected from the group consisting of one or more fluorinated organic compounds;
b. An absorbent comprising one or more fluorinated organic compounds having 1 to 8 carbon atoms (C1-C8) having a boiling point at least 40 ° C. higher than the boiling point of the refrigerant;
c. An evaporation device suitable for evaporating said refrigerant;
d. A mixer suitable for mixing the refrigerant with the absorbent, wherein the mixer is fluidly connected to the evaporator;
e. An absorber suitable for dissolving at least a part of the refrigerant in the absorbent to form a solution, wherein the absorber is fluidly connected to the mixer;
f. A pump fluidly connected to said absorber;
g. A heat exchanger fluidly connected to the pump;
h. A separation device suitable for thermodynamic separation of said solution into a vapor refrigerant component and a liquid absorbent component, wherein said separation device is fluidly connected to said heat exchanger;
i. A return oil line fluidly connected to the separation device and the mixer; and
j. A condensing device suitable for condensing the vapor refrigerant component, wherein the condensing device is fluidly connected to the separating device and the evaporating device.
Including absorption refrigeration system.

1 line 2 line 4 line 5 line 6 line 7 line 8 line 9 line 10 line 12 line 13 line 14 line 15 line 16 line 17 line 20 mixer 22 absorber 24 pump 26 heat exchanger / boiler 28 separator 30 oil valve 32 Condenser 34 Expansion valve 36 Evaporator 40 Mixer 42 First absorber 44 First pump 46 First heat exchanger / boiler 48 Second mixer 50 Second absorber 52 Second pump 54 Second boiler 56 Separator 58 T Pipe 60 Second oil valve 62 First oil valve 64 Condenser 66 Expansion valve 68 Evaporator

Claims (8)

Less than:
a. Low pressure gas phase refrigerant stream by evaporating a first liquid phase refrigerant stream comprising one or more fluorinated organic compounds selected from the group consisting of HFCs, HFOs and HFCOs having 1 to 8 carbon atoms Where said evaporation transfers heat from the system and causes it to cool;
b. The low-pressure gas-phase refrigerant stream consists of fluoroethers, fluoroketones, HFCs, HFOs and HFCOs having a total number of carbon / oxygen atoms that is at least 2 greater than the total number of carbon / oxygen atoms in the refrigerant. Effective in dissolving a first liquid phase solvent stream comprising one or more organic compounds selected from the group and substantially all of the refrigerant of the gas phase refrigerant stream in the solvent of the first liquid phase solvent stream Contacting under mild conditions to produce a refrigerant-solvent solution stream;
c. Increasing the pressure and temperature of the refrigerant-solvent solution stream;
d. Thermodynamically separating the refrigerant-solvent solution stream into a high pressure gas phase refrigerant stream and a second liquid phase solvent stream;
e. Recirculating said second liquid phase solvent stream to step (b) to produce said first liquid phase solvent stream;
f. Condensing said high pressure gas phase refrigerant stream to produce a second liquid phase refrigerant stream; and g. A method for providing absorption refrigeration comprising recirculating the second liquid phase refrigerant stream to step (a) to produce the first liquid phase refrigerant stream. The one or more organic compounds in the first liquid phase solvent stream have a boiling point that is at least 40 ° C. higher than the boiling point of the one or more fluorinated organic compounds in the first liquid phase refrigerant stream; The method of claim 1. The one or more fluorinated organic compounds in the first liquid phase refrigerant stream are 1,1,1,2-tetrafluoropropene, difluoromethane, trans-1,1,1,3-tetrafluoropropene. The method of claim 1 , wherein the method is selected from one or more of cis-1,1,1,3-tetrafluoropropene, 3,3,3-trifluoropropene, and combinations thereof. The organic compound in the first liquid phase solvent stream is nonafluorobutyl ether, perfluoro (2-methyl-3-pentanone), 1,1,1,3,3-pentafluoropropane, 1-chloro-3,3. The method of claim 1 , wherein the method is selected from the group consisting of 1,3-trifluoropropene, and combinations thereof. The one or more fluorinated organic compounds in the first liquid phase refrigerant stream are 1,1,1,2-tetrafluoropropene, difluoromethane, trans-1,1,1,3-tetrafluoropropene, Selected from one or more of cis-1,1,1,3-tetrafluoropropene, 3,3,3-trifluoropropene, and combinations thereof; The organic compound is nonafluorobutyl ether, perfluoro (2-methyl-3-pentanone), 1,1,1,3,3-pentafluoropropane, 1-chloro-3,3,3-trifluoropropene, and combinations thereof The method of claim 1, wherein the method is selected from the group consisting of: Comprising at least one compound of one or more fluorinated organic compound of the first liquid phase refrigerant stream in said has the formula _{C w H x F y Cl z} , where integer w is from 3 to 5 The method of claim 1, wherein x is an integer from 1 to 3, z is an integer from 0 to 1, and y = 2w−x−z.   The process according to claim 1, wherein the solvent is selected from the group consisting of polyethylene glycol oil, polyol ester oil, oil based on polypropylene glycol dimethyl ether and mineral oil. Less than:
a. A refrigerant selected from the group consisting of one or more fluorinated organic compounds selected from the group consisting of HFCs, HFOs and HFCOs ;
b. An absorbent comprising one or more fluorinated organic compounds having 1 to 8 carbon atoms (C1-C8) having a boiling point at least 40 ° C. higher than the boiling point of the refrigerant;
c. An evaporation device suitable for evaporating said refrigerant;
d. A mixer suitable for mixing the refrigerant with the absorbent, wherein the mixer is fluidly connected to the evaporator;
e. An absorber suitable for dissolving at least a part of the refrigerant in the absorbent to form a solution, wherein the absorber is fluidly connected to the mixer;
f. A pump fluidly connected to said absorber;
g. A heat exchanger fluidly connected to the pump;
h. A separation device suitable for thermodynamic separation of said solution into a vapor refrigerant component and a liquid absorbent component, wherein said separation device is fluidly connected to said heat exchanger;
i. A return oil line fluidly connected to the separator and the mixer; and j. An absorption refrigeration system suitable for condensing the vapor refrigerant component, wherein the condensing device is fluidly connected to the separation device and the evaporation device.

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