LOW GWP HEAT TRANSFER COMPOSITIONS
20230125257 · 2023-04-27
Assignee
Inventors
- Ryan Hulse (Charlotte, NC, US)
- Ronald Vogl (Charlotte, NC, US)
- Kyle Cuellar (Charlotte, NC, US)
- Oluwaseyi Kayode (Charlotte, NC, US)
Cpc classification
C09K5/042
CHEMISTRY; METALLURGY
International classification
Abstract
Refrigerants comprising from about 40% to about 60% by weight carbon dioxide (CO2), from about 30% to about 45% by weight of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)), and from 2.0% to about 15% by weight of trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E).
Claims
1. A refrigerant comprising at least about 98.5% by weight of the following three compounds, with each compound being present in the following relative percentages: about 40% to about 60% by weight carbon dioxide (CO2); about 30% to about 45% by weight of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)); and 2.0% to about 15% by weight of trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E)).
2. The refrigerant of claim 1 comprising the following three compounds in the following relative percentages: about 50% to about 60% by weight CO.sub.2; about 35% to about 45% by weight of HFO-1234ze(E); and about 5% to about 10% by weight of HFCO-1233zd(E).
3. The refrigerant of claim 1 comprising the following three compounds in the following relative percentages: about 50% to about 55% by weight CO.sub.2; about 35% to about 40% by weight of HFO-1234ze(E); and about 5% to about 10% by weight of HFCO-1233zd(E).
4. The refrigerant of claim 1 comprising the following three compounds in the following relative percentages: about 54% by weight CO.sub.2; about 38% by weight of HFO-1234ze(E); and about 8% by weight of HFCO-1233zd(E).
5. The refrigerant of claim 1 comprising the following three compounds in the following relative percentages: 54%+/−1% by weight CO.sub.2; 38%+/−1% by weight of HFO-1234ze(E); and 8%+/−1% by weight of HFCO-1233zd(E).
6. The refrigerant of any claim 1 consisting of CO.sub.2, HFO-1234ze(E); and HFCO-1233zd(E).
7. A low temperature refrigeration system comprising a refrigerant of claim 1.
8. A cryogenic refrigeration system comprising a refrigerant of claim 1.
9. A method cooling comprising evaporating a refrigerant of claim 1.
10. A method of cooling using a system of claim 8.
11. A method of separating components contained in a process stream by cooling a process stream using a refrigerant of claim 1.
12. A method of separating components contained in a process stream by cooling a process stream using a system of claim 8.
13. A method of separating components contained in a process stream comprising the method of claim 10.
14. A method according to claim 13 wherein the process stream comprises a synthetic gas stream or a portion thereof.
15. The method of claim 14 wherein said process stream comprises at least hydrogen and CO.sub.2.
16. The method of claim 14 wherein said separating step comprises separating hydrogen from CO.sub.2.
17. A refrigerant consisting essentially of: about 40% to about 60% by weight carbon dioxide (CO.sub.2); about 30% to about 45% by weight of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)); and 2.0% to about 15% by weight of trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E)).
18. A cryogenic refrigeration system comprising the refrigerant of claim 17.
19. A method of separating components contained in a process stream by cooling a process stream using a refrigerant of claim 17.
20. A refrigerant consisting essentially of: 54%+/−1% by weight CO.sub.2; 38%+/−1% by weight of HFO-1234ze(E); and 8%+/−1% by weight of HFCO-1233zd(E).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0074]
[0075]
[0076]
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0077] For the purposes of this invention, the term “about” in relation to the amounts expressed in weight percent means that the amount of the component can vary by an amount of +/−2% by weight.
[0078] For the purposes of this invention, the term “about” in relation to temperatures in degrees centigrade (° C.) means that the stated temperature can vary by an amount of +/−5° C.
[0079] The term “capacity” is the amount of cooling provided, in BTUs/hr, by the refrigerant in the refrigeration system. This is experimentally determined by multiplying the change in enthalpy in BTU/lb, of the refrigerant as it passes through the evaporator by the mass flow rate of the refrigerant. The enthalpy can be determined from the measurement of the pressure and temperature of the refrigerant. The capacity of the refrigeration system relates to the ability to maintain an area to be cooled at a specific temperature. The capacity of a refrigerant represents the amount of cooling or heating that it provides and provides some measure of the capability of a compressor to pump quantities of heat for a given volumetric flow rate of refrigerant. In other words, given a specific compressor, a refrigerant with a higher capacity will deliver more cooling or heating power.
[0080] The phrase “coefficient of performance” (hereinafter “COP”) is a universally accepted measure of refrigerant performance, especially useful in representing the relative thermodynamic efficiency of a refrigerant in a specific heating or cooling cycle involving evaporation or condensation of the refrigerant. In refrigeration engineering, this term expresses the ratio of useful refrigeration or cooling capacity to the energy applied by the compressor in compressing the vapor and therefore expresses the capability of a given compressor to pump quantities of heat for a given volumetric flow rate of a heat transfer fluid, such as a refrigerant. In other words, given a specific compressor, a refrigerant with a higher COP will deliver more cooling or heating power. One means for estimating COP of a refrigerant at specific operating conditions is from the thermodynamic properties of the refrigerant using standard refrigeration cycle analysis techniques (see for example, R. C. Downing, FLUOROCARBON REFRIGERANTS HANDBOOK, Chapter 3, Prentice-Hall, 1988 which is incorporated herein by reference in its entirety).
[0081] The phrase “discharge temperature” refers to the temperature of the refrigerant at the outlet of the compressor. The advantage of a low discharge temperature is that it permits the use of existing equipment without activation of the thermal protection aspects of the system which are preferably designed to protect compressor components and avoids the use of costly controls such as liquid injection to reduce discharge temperature.
[0082] The phrase “Global Warming Potential” (hereinafter “GWP”) was developed to allow comparisons of the global warming impact of different gases. Specifically, it is a measure of how much energy the emission of one ton of a gas will absorb over a given period of time, relative to the emission of one ton of carbon dioxide. The larger the GWP, the more that a given gas warms the Earth compared to CO2 over that time period. The time period usually used for GWP is 100 years. GWP provides a common measure, which allows analysts to add up emission estimates of different gases. See http://www.protocolodemontreal.org.br/site/images/publicacoes/setor_manufatura_equipamentos_refrigeracao_arcondicionado/Como_calcular_el_Potencial_de_Calentamiento_Atmosferico_en_las_mezclas_de_re frigerantes.pdf
[0083] The term “Occupational Exposure Limit (OEL)” is determined in accordance with ASHRAE Standard 34-2016 Designation and Safety Classification of Refrigerants.
[0084] The term “mass flow rate” is the mass of refrigerant passing through a conduit per unit of time.
[0085] The phrase “thermodynamic glide” applies to zeotropic refrigerant mixtures that have varying temperatures during phase change processes in the evaporator or condenser at constant pressure.
[0086] The term “low temperature refrigeration” refers to heat transfer systems and methods which operate with the refrigerant evaporating at a temperature of from about −45° C. and up to and about ambient.
[0087] The term “cryogenic refrigeration” refers to heat transfer systems and methods which operate with the refrigerant evaporating at a temperature of less than about −45° C.
Refrigerants and Heat Transfer Compositions
[0088] Applicants have found that the refrigerants of the present invention, including each of Refrigerants 1-15 as described herein, is capable of providing one or more exceptionally advantageous properties including: heat transfer properties, low or no toxicity, mild flammability (Class 2L) and more preferably non-flammability (Class 1), near zero ozone depletion potential (“ODP”), and lubricant compatibility, including acceptable miscibility with POE and/or PVE lubricants including preferably over the operating temperature range of the refrigerant in low-temperature and cryogenic refrigeration.
[0089] Applicants have found that the refrigerant compositions of the invention, including each of Refrigerants 1-15, are capable of achieving a difficult to achieve combination of properties including particularly low GWP. Thus, the compositions of the invention have a GWP of 150 or less and preferably 75 or less.
[0090] In addition, the refrigerant compositions of the invention, including each of Refrigerants 1-15, have a low ODP. Thus, the compositions of the invention have an ODP of not greater than 0.05, preferably not greater than 0.02, and more preferably about zero.
[0091] In addition, the refrigerant compositions of the invention, including each of Refrigerants 1-15, show acceptable toxicity and preferably have an OEL of greater than about 400. As those skilled in the art are aware, a non-flammable refrigerant that has an OEL of greater than about 400 is advantageous since it results in the refrigerant being classified in the desirable Class 1A of ASHRAE standard 34.
[0092] Applicants have found that the heat transfer compositions of the present invention, including heat transfer compositions that include each of Refrigerants 1-15 as described herein, is capable of providing an exceptionally advantageous and unexpected combination of properties including: heat transfer properties, chemical stability under the conditions of use, low or no toxicity, mild-flammability or non-flammability, near zero ozone depletion potential (“ODP”), sub-150 GWP, and acceptable lubricant compatibility, including acceptable miscibility with POE and/or PVE lubricants.
[0093] The heat transfer compositions can consist essentially of any refrigerant of the present invention, including each of Refrigerants 1-15.
[0094] The heat transfer compositions of the present invention can consist of any refrigerant of the present invention, including each of Refrigerants 1-15.
[0095] The heat transfer compositions of the invention may include other components for the purpose of enhancing or providing certain functionality to the compositions. Such other components may include, in addition to the refrigerant of the present invention, including each of Refrigerants 1-15, one or more of lubricants, passivators, flammability suppressants, dyes, solubilizing agents, compatibilizers, stabilizers, antioxidants, corrosion inhibitors, extreme pressure additives and anti-wear additives and other compounds and/or components that modulate a particular property of the heat transfer composition, and the presence of all such compounds and components is within the broad scope of the invention.
[0096] Lubricants
[0097] The heat transfer composition of the invention particularly comprises a refrigerant as described herein, including each of Refrigerants 1-15, and a lubricant. Applicants have found that the heat transfer compositions of the present invention, including heat transfer compositions that include a lubricant, and particularly a POE and/or PVE lubricant and each of Refrigerants 1-15 as described herein, is capable of providing exceptionally advantageous properties including, in addition to the advantageous properties identified herein with respect to the refrigerant, excellent refrigerant/lubricant compatibility, including acceptable miscibility with POE and/or PVE lubricants over the operating temperature and concentration ranges for the intended use, including particularly low-temperature refrigeration and cryogenic refrigeration.
[0098] Commonly used refrigerant lubricants such as polyol esters (POEs), polyalkylene glycols (PAGs), PAG oils, silicone oils, mineral oil, alkylbenzenes (ABs), polyvinyl ethers (PVEs), polyethers (PEs) and poly(alpha-olefin) (PAO) that are used in refrigeration machinery may be used with the refrigerant compositions of the present invention.
[0099] Preferably the lubricants are selected from PAGs, POEs, and PVE.
[0100] Preferably the lubricants comprise POEs.
[0101] Preferably the lubricants comprise PVEs.
[0102] Preferably the lubricants comprise PAGs.
[0103] In general, the heat transfer compositions of the present invention that include POE lubricant comprise POE lubricant in amounts preferably of from about 0.1% by weight to about 5%, or from 0.1% by weight to about 1% by weight, or from 0.1% by weight to about 0.5% by weight, based on the weight of the heat transfer composition.
[0104] Commercially available POEs that are preferred for use in the present heat transfer compositions include neopentyl glycol dipelargonate which is available as Emery 2917 (registered trademark) and Hatcol 2370 (registered trademark) and pentaerythritol derivatives including those sold under the trade designations Emkarate RL32-3MAF and Emkarate RL68H by CPI Fluid Engineering. Emkarate RL32-3MAF and Emkarate RL68H are preferred POE lubricants having the properties identified below:
TABLE-US-00002 RL32- Property 3MAF RL68H Viscosity about 31 about 67 @ 40° C. (ASTM D445), cSt Viscosity about 5.6 about 9.4 @ 100° C. (ASTM D445), cSt Pour Point about −40 about −40 (ASTM D97), ° C.
[0105] In general, the heat transfer compositions of the present invention that include PVE lubricant comprise PVE lubricant in amounts preferably of from about 0.1% by weight to about 5%, or from 0.1% by weight to about 1% by weight, or from 0.1% by weight to about 0.5% by weight, based on the weight of the heat transfer composition.
[0106] Commercially available polyvinyl ethers that are preferred for use in the present heat transfer compositions include those lubricants sold under the trade designations FVC32D and FVC68D, from Idemitsu.
[0107] Commercially available PAG lubricants are preferred for use in the present heat transfer compositions include those lubricants sold under the trade designations Nippon-Denso ND oil-8, ND oil-12; Idemitsu PS-D1; Sanden SP-10.
[0108] Other additives not mentioned herein can also be included by those skilled in the art in view of the teaching contained herein without departing from the novel and basic features of the present invention.
Methods, Uses and Systems
[0109] The refrigerants, including Refrigerants 1-15, and heat transfer compositions as disclosed herein, are provided for use in heat transfer applications, including low-temperature refrigeration and cryogenic refrigeration.
[0110] For heat transfer systems of the present invention that include a compressor and lubricant for the compressor in the system, the system can comprises a loading of refrigerant and lubricant such that the lubricant loading in the system is from about 5% to 60% by weight, or from about 10% to about 60% by weight, or from about 20% to about 50% by weight, or from about 20% to about 40% by weight, or from about 20% to about 30% by weight, or from about 30% to about 50% by weight, or from about 30% to about 40% by weight. As used herein, the term “lubricant loading” refers to the total weight of lubricant contained in the system as a percentage of total of lubricant and refrigerant contained in the system. Such systems may also include a lubricant loading of from about 5% to about 10% by weight, or about 8% by weight of the heat transfer composition.
[0111] Exemplary Heat Transfer Systems
[0112] As described in more detail below, the preferred systems of the present invention comprise a compressor, a condenser, an expansion device and an evaporator, all connected in fluid communication using piping, valving and control systems such that the refrigerant and associated components of the heat transfer composition can flow through the system in known fashion to complete the refrigeration cycle. An exemplary schematic of such a basic system is illustrated in
[0113] Low-Temperature Systems and Methods
[0114] The heat transfer systems according to the present invention include low-temperature heat transfer systems that comprise a compressor, an evaporator, a condenser and an expansion device, in fluid communication with each other, a refrigerant of the invention, including each of Refrigerants 1-15, a lubricant, including a POE lubricant, a PVE lubricant or combinations of these.
[0115] The heat transfer methods according to the present invention include low-temperature heat transfer methods that include step of evaporating a refrigerant of the invention, including each of Refrigerants 1-15, in a temperature range of from about −45° C. to about ambient.
[0116] Cryogenic Systems and Methods
[0117] The heat transfer systems according to the present invention include cryogenic heat transfer systems that comprise a compressor, an evaporator, a condenser and an expansion device, in fluid communication with each other, a refrigerant of the invention, including each of Refrigerants 1-15, and a lubricant, including a POE lubricant, a PVE lubricant and combinations of these.
[0118] The heat transfer methods according to the present invention include cryogenic heat transfer methods that include step of evaporating a refrigerant of the invention, including each of Refrigerants 1-15, in a temperature of about −45° C. or less.
[0119] Exemplary Uses
[0120] In highly preferred uses of the present invention, the refrigerants of the present invention, including each of Refrigerants 1-15, are used as part of a process of and/or as part of a system for separating components, or at least portions of components, of a composition, particularly wherein such separation occurs at temperatures in the range of low-temperature refrigeration and/or cryogenic refrigeration. Non-limiting examples of such separation processes are disclosed in: U.S. Provisional Application 63/167,338, filed Mar. 29, 2021; U.S. Provisional Application 63/167,341, filed Mar. 29, 2021; and U.S. Provisional Application 63/167,341, filed Mar. 29, 2021, each of which is incorporated herein by reference.
[0121]
[0122] The feed stream 931 is split into two streams (stream 939 and 940). Stream 939 is cooled in heat exchanger 911 by heat exchange with cool carbon dioxide vapor (stream 938c) and cold residue gas (stream 933a). Stream 940 is cooled in heat exchanger 910 by heat exchange with column reboiler liquids (stream 936) and column side reboiler liquids (stream 935). The cooled streams from heat exchangers 910 and 911 are recombined into stream 931a.
[0123] Stream 931a is then further cooled with a refrigerant 950, preferably a refrigerant of the present invention, including each of Refrigerants 1-15, and the resultant stream (cooled stream 931b) is expanded to the operating pressure of fractionation tower 913 by expansion valve 912, cooling stream 931c before it is supplied to fractionation tower 913 at its top column feed point.
[0124] Overhead vapor stream 932 leaves fractionation tower 913 and is cooled and partially condensed in heat exchanger 914. The partially condensed stream 932a enters separator 915 where the vapor (cold residue gas stream 933) is separated from the condensed liquid stream 934. Condensed liquid stream 934 is pumped to slightly above the operating pressure of fractionation tower 913 by pump 919 before liquid stream 934a enters heat exchanger 916 and is heated and partially vaporized by heat exchange with carbon dioxide refrigerant from the bottom of the distillation column (described below). The partially vaporized stream 934b is thereafter supplied as feed to fractionation tower 913 at a mid-column feed point. A cold compressor (not shown) can be applied to overhead vapor stream 932 if higher pressure and/or lower carbon dioxide content is desired in the feed to the a pressure swing absorption (PSA) system. If a compressor is used on this stream, then the pump 919 can be eliminated, and the liquid from separator 915 would then be sent to fractionation tower 913 via a liquid level control valve.
[0125] Fractionation tower 913 is a conventional distillation column containing a plurality of vertically spaced trays, one or more packed beds, or some combination of trays and packing. It also includes reboilers (such as the reboiler and the side reboiler described previously) which heat and vaporize a portion of the liquids flowing down the column to provide the stripping vapors which flow up the column to strip the column bottom liquid product stream 937 of hydrogen and lighter components. The trays and/or packing provide the necessary contact between the stripping vapors rising upward and cold liquid falling downward, so that the column bottom liquid product stream 937 exits the bottom of the tower, based on reducing the hydrogen and lighter component concentration in the bottom product to make a very pure carbon dioxide product.
[0126] Column bottom liquid product stream 937 is predominantly liquid carbon dioxide. A small portion (stream 938) is subcooled in heat exchanger 916 by liquid stream 934a from separator 915 as described previously. The subcooled liquid (stream 938a) is expanded to lower pressure by expansion valve 920 and partially vaporized, further cooling stream 938b before it enters heat exchanger 914. Stream 938b functions as refrigerant in heat exchanger 914 to provide cooling of partially condensed stream 932a as described previously, with the resulting carbon dioxide vapor leaving as stream 938c.
[0127] The cool carbon dioxide vapor from heat exchanger 914 (stream 938c) is heated in heat exchanger 911 by heat exchange with the feed gas as described previously. The warm carbon dioxide vapor (stream 938d) is then compressed to a pressure above the pressure of fractionation tower 913 in three stages by compressors 921, 923, and 925, with cooling after each stage of compression by discharge coolers 922, 924, and 926. The compressed carbon dioxide stream (stream 938j) is then flash expanded through valve 942 and returned to a bottom feed location in fractionation tower 913. The recycled carbon dioxide (stream 938k) provides further heat duty and stripping gas in fractionation tower 913. The remaining portion (stream 941) of column bottom liquid product stream 937 is pumped to high pressure by pump 929 so that stream 941a forms a high pressure carbon dioxide stream which then flows to pipeline or reinjection. In certain instances, the carbon dioxide stream needs to be delivered as a sub-cooled liquid at lower pressure that can be transported in insulated shipping containers. For these cases, the carbon dioxide product (stream 941) is sub-cooled in heat exchanger 917 with refrigerant 950 before being let down to storage tank conditions. Therefore pump 929 is eliminated.
[0128] The cold residue gas stream 933 leaves separator 915 and provides additional cooling in heat exchanger 914. The warmed residue gas stream 933a is further heated after heat exchange with the feed gas in heat exchanger 911 as described previously. The warm residue gas stream 933b is then sent to the PSA system for further treating.
[0129]
[0130] The feed stream 931 is usually dehydrated to prevent hydrate (ice) formation under cryogenic conditions. Solid and liquid desiccants have both been used for this purpose. The feed stream 931 is cooled in heat exchanger 910 by heat exchange with column reboiler liquids (stream 936) and column side reboiler liquids (stream 935). Stream 931a is further cooled in heat exchanger 911 by heat exchange with cold residue gas stream 933, and at least a first pass of a refrigerant 950 of the present invention, including a refrigerant according to each of Refrigerants 1-15. In preferred embodiments, the refrigerant 950 of the present invention makes a first pass through the heat exchanger 911 and then is flashed across an expansion valve to a lower pressure before making a second pass through the heat exchanger 911. The refrigerant of the present invention can provide a highly efficient cooling curve in heat exchanger 911 based on the inlet gas feed conditions. The further cooled stream 931b is expanded to the operating pressure of fractionation tower 913 by expansion valve 912, and sent to fractionation tower 913 at a mid-column feed point.
[0131] Overhead vapor stream 932 leaves fractionation tower 913 and is cooled and partially condensed in heat exchanger 911 with the mixed refrigerant stream. The partially condensed stream 932a enters separator 915 where the vapor (cold residue gas stream 933) is separated from the condensed liquid stream 934. Condensed liquid stream 934 is pumped to slightly above the operating pressure of fractionation tower 913 by pump 919 before liquid stream 934a is sent to fractionation tower 913 at the top feed point. A cold compressor (not shown) can be applied to overhead vapor stream 932 if higher pressure and/or lower carbon dioxide content is desired in the feed to the PSA system. If a compressor is used on this stream, then the pump 919 can be eliminated, and the liquid from separator 915 would then be sent to fractionation tower 913 via a liquid level control valve.
[0132] Fractionation tower 913 is a conventional distillation column containing a plurality of vertically spaced trays, one or more packed beds, or some combination of trays and packing. It also includes reboilers (such as the reboiler and the side reboiler described previously) which heat and vaporize a portion of the liquids flowing down the column to provide the stripping vapors which flow up the column to strip the column bottom liquid product stream 937 of hydrogen and lighter components. The trays and/or packing provide the necessary contact between the stripping vapors rising upward and cold liquid falling downward, so that the column bottom liquid product stream 937 exits the bottom of the tower, based on reducing the hydrogen and lighter component concentration in the bottom product to make a very pure carbon dioxide product.
[0133] Column bottom liquid product stream 937 is predominantly liquid carbon dioxide. Column bottom liquid product stream 937 is pumped to high pressure by pump 929 so that stream 937a forms a high pressure carbon dioxide stream which then flows to pipeline or reinjection. In certain instances, the carbon dioxide stream needs to be delivered as a sub-cooled liquid at lower pressure that can be transported in insulated shipping containers. For these cases, the carbon dioxide product in column bottom liquid product stream 937 is sub-cooled in heat exchanger 911 with mixed refrigerant 950 before being let down to storage tank conditions. Therefore pump 929 is eliminated.
[0134] The warm residue gas stream 933a leaves heat exchanger 911 after heat exchange with the feed gas as described previously. The warm residue gas stream 933a is then sent to the PSA system for further treating.
[0135] A preferred relationship between the equipment shown in
Equipment for the Systems, Methods and Uses
[0136] Examples of commonly used compressors, for the purposes of this invention include reciprocating, rotary (including rolling piston and rotary vane), scroll, screw, and centrifugal compressors. Thus, the present invention provides each and any of the refrigerants, including each of Refrigerants 1-15, and/or heat transfer compositions as described herein, including those containing any one of Refrigerants 1-15, for use in a heat transfer system comprising a reciprocating, rotary (including rolling piston and rotary vane), scroll, screw, or centrifugal compressor.
[0137] Examples of commonly used expansion devices, for the purposes of this invention include a capillary tube, a fixed orifice, a thermal expansion valve and an electronic expansion valve. Thus, the present invention provides each and any of the refrigerants, including each of Refrigerants 1-15, and/or heat transfer compositions, including those containing any one of Refrigerants 1-15, as described herein for use in a heat transfer system comprising a capillary tube, a fixed orifice, a thermal expansion valve or an electronic expansion valve.
[0138] For the purposes of this invention, the evaporator and the condenser can each independently be selected from a finned tube heat exchanger, a microchannel heat exchanger, a shell and tube, a plate heat exchanger, and a tube-in-tube heat exchanger. Thus, the present invention provides each and any of the refrigerants and/or heat transfer compositions as described herein for use in a heat transfer system wherein the evaporator and condenser together form a finned tube heat exchanger, a microchannel heat exchanger, a shell and tube, a plate heat exchanger, or a tube-in-tube heat exchanger.
EXAMPLES
[0139] The following examples are provided for the purpose of illustrating the present invention but without limiting the scope thereof.
Comparative Example 1—Flammability
[0140] A refrigerant composition as indicated below which is not a refrigerant of the present invention is evaluated for purposes of comparison to refrigerant of the present invention:
TABLE-US-00003 TABLE CE1 CE1 Component Wt % CO.sub.2 50 Propane 36 IsoPentane 14 Total 100.0
A cylinder containing the refrigerant blend as identified above is allowed to slowly leak from the vapor valve until 20% of the contents are removed. This simulates a vapor leak from a refrigeration system. The liquid that remains in the cylinder is then expanded and found to have flame limits as determined according to ASTM-E681 at 23 C, which means the remaining contents of the cylinder are flammable.
Example 1—Flammability
[0141] A refrigerant composition of the present invention, as shown in Table 1 below, is evaluated:
TABLE-US-00004 TABLE E1 E1 Component Wt % CO.sub.2 54 1234ze (E) 38 1233zd(E) 18 Total 100.0 GWP 1
The process of Comparative Example 1 is repeated with the refrigerant of Table E1, that is, a cylinder containing the refrigerant blend as identified above is allowed to slowly leak from the vapor valve until 20% of the contents are removed. This simulates a vapor leak from a refrigeration system. The liquid that remains in the cylinder is then expanded and found to not have flame limits as determined according to ASTM-E681 at 23° C., which means the remaining contents of the cylinder are nonflammable, which means the blend of Table E1 would be Class A1.
Example 2: Low-Temperature Refrigeration Application—Performance
[0142] Due to certain characteristics of refrigeration systems, including particularly low temperature refrigeration systems, it is important in certain embodiments that such systems are capable of exhibiting adequate performance parameters system with respect to previously used refrigerants in low-temperature systems.
[0143] A first system of the type as disclosed in U.S. Provisional Application 63/167,338, filed Mar. 29, 2021, is operated in a dual refrigerant process as illustrated in
[0144] A second system of the type as disclosed in U.S. Provisional Application 63/167,338, filed Mar. 29, 2021, is operated in mixed refrigerant process as illustrated in
Example 3: Low-Temperature Refrigeration Application—Performance
[0145] Due to certain characteristics of refrigeration systems, including particularly low temperature refrigeration systems, it is important in certain embodiments that such systems are capable of exhibiting adequate performance parameters system with respect to previously used refrigerants in low-temperature systems. Such operating parameters include: [0146] Capacity of at least 90%, and even more preferably greater than 95% of the capacity of the system operating with the prior refrigerant. This parameter allows the use of existing compressors and components designed for the use of the prior refrigerant. [0147] Equal or better efficiency than the prior refrigerant, leading to energy savings with new mixture. [0148] Equal or lower energy consumption
Low temperature refrigeration systems can be used, for example, in an air-to-fluid evaporator (where the fluid is being cooled), a reciprocating, scroll or screw compressor, an air-to-refrigerant condenser to exchange heat with the ambient air, and a thermal or electronic expansion valve.
[0149] This example illustrates the COP and capacity performance of the Table E1 composition compared to a typical prior refrigerant used in low temperature systems, namely, R410A in a low-temperature refrigeration system. The low temperature refrigeration system of this example is tested using the refrigerant of Table E1 and the performance results are in Table E3 below compared to operation with R410A. Operating conditions were: Condensing temperature=40.6° C.; Condenser sub-cooling=1° C.; Evaporating temperature=−31.6° C.; Degree of superheat at evaporator outlet=5.5° C.; Isentropic Efficiency=70%; Volumetric Efficiency=100%; Degree of superheat in the suction line=30.6° C.
TABLE-US-00005 TABLE E3 Performance in Low Temperature Refrigeration System Pressure Discharge Capacity Efficiency ratio Pressure Refrigerant (% R410A) (% R410A) (% R410A) (% R410A) R410A .sup. 100% .sup. 100% .sup. 100% .sup. 100% E1 =>95% =>95% =<105% 95-105%
[0150] As shown above in Table E3, the thermodynamic performance of a low temperature refrigeration system using a refrigerant of the present invention is excellent compared to performance of R410A in the system, having a capacity and efficiency that is 95% or greater compared to the values when R410A is operated in the system.