KR20180107280A - Multistage Low GWP Air Conditioning System - Google Patents

Abstract

A refrigerant system for conditioning air and / or an article located within a residence occupied by a human or other animal, the system comprising: at least a first heat transfer fluid containing a first heat transfer fluid in a vapor / One heat transfer circuit and at least a second heat transfer circuit containing a second heat transfer fluid different from the first heat transfer fluid substantially located within the residence. In a preferred embodiment, the second heat transfer circuit does not include a vapor compressor, but the system includes at least one intermediate heat exchanger that enables heat exchange between the first heat transfer fluid and the second heat transfer fluid, Is transferred to the first heat transfer fluid, preferably by this thereby evaporating the first heat transfer fluid, thereby condensing the second heat transfer fluid from the second heat transfer fluid. Preferably, the intermediate heat exchanger is located outside the residence. The first heat transfer fluid comprises a refrigerant having a GWP of about 500 or less and the second heat transfer fluid also has a GWP of less than 500 and is less flammable and less toxic, A flammability that is substantially less than the flammability of the refrigerant and / or a substantially lower toxicity than the toxicity of the refrigerant in the first heat transfer fluid.

Description

Multistage Low GWP Air Conditioning System

This application claims priority of U.S. Provisional Application No. 62 / 295,731, filed February 16, 2016, the entire contents of which are incorporated herein by reference.

The present invention relates to a safe and effective high efficiency, low-global warming index ("low GWP") air conditioning and associated cooling system and method.

In typical air conditioning and refrigerant systems, compressors are used to compress heat transfer vapors from low pressure to high pressure, which in turn heat the steam. This additional heat is rejected in a heat exchanger, which is typically referred to as a condenser. In a condenser, the vapor condenses at least in a major proportion to produce a liquid heat transfer fluid at a relatively high pressure. Typically, a condenser uses a fluid that can be used in large quantities as a heat sink in the surrounding environment, such as ambient air around it. Once condensed, the high pressure heat transfer fluid undergoes a substantially isoenthalpic expansion, such as by passing through an expansion device or valve, where it is expanded to a lower pressure, which in turn causes the fluid . Then, the lower pressure, lower temperature heat transfer fluid from the expansion operation is typically sent to the evaporator, where it absorbs heat and evaporates. This evaporation process in turn causes cooling of the fluid or body to be cooled. In a typical air conditioning application, the cooled fluid is room air in an air conditioned residential area. In a cooling system, cooling may include cooling the air inside the cold box or storage unit. The heat transfer fluid is evaporated from the evaporator to low pressure and then returned to the compressor where the cycle is resumed.

The combination of complex and interrelated factors and requirements is associated with forming an efficient, effective, and safe air conditioning system that is both environmentally friendly, ie having both low GWP impacts and low ozone depletion ("ODP") impacts. With regard to efficiency and effectiveness, it is important that the heat transfer fluid is operated in an air conditioning system with a high level of efficiency and high capacity. At the same time, it is important that the fluid has a low value for both GWP and ODP, since it is possible for the heat transfer fluid to escape to the atmosphere over time.

Certain fluids can achieve both high levels of efficiency and effectiveness, while at the same time achieving both low GWP and ODP, applicants have found that many fluids meeting the combination of requirements are nonetheless defective in terms of safety And that there is a disadvantage with this. For example, other acceptable fluids may be unfavorable for use due to flammability and / or toxicity issues. The use of fluids having these properties has become particularly noteworthy in typical air conditioning systems because they are inadvertently placed into residential areas where such flammable and / or toxic fluids are cooled (or heated in the case of heat-pump applications) , Thus exposing the occupant to a hazardous condition or potentially exposing it to the occupant.

According to one aspect of the present invention, there is provided a refrigerant system for conditioning air and / or an article located within a residence occupied by a human or other animal. A preferred implementation of such a system includes at least a first heat transfer circuit, which preferably includes a first heat transfer fluid in a vapor / compression circulation loop substantially located outside the residence. This first circuit is also referred to herein as an " outdoor loop "for convenience. The outdoor loop preferably includes a compressor, a heat exchanger that serves to condense the heat transfer fluid in the outdoor loop, preferably by heat exchange with outdoor ambient air, and an expansion device. The preferred system also includes at least a second heat transfer circuit, which contains a second heat transfer fluid different from the first heat transfer fluid substantially located within the residence. This second circuit is also referred to herein as an "indoor loop" for convenience. The indoor loop preferably includes an evaporator heat exchanger that serves to evaporate the second heat transfer fluid in the indoor loop, preferably by heat exchange with the room air. In a preferred embodiment, the second heat transfer circuit does not include a vapor compressor.

The preferred system preferably includes at least one intermediate heat exchanger, which transfers heat to the first heat transfer fluid, preferably thereby evaporating the first heat transfer fluid, Thereby allowing heat exchange between the first heat transfer fluid and the second heat transfer fluid to condense the two heat transfer fluids. Preferably, the intermediate heat exchanger is located outside or outside the area where the air is conditioned.

An important aspect of the preferred system is that the first heat transfer fluid comprises a refrigerant having a GWP of about 500 or less, more preferably about 400 or less, more preferably about 150 or less, and the second heat transfer fluid also has a Preferably less than or equal to about 400, more preferably less than or equal to 150, and has a low flammability and low toxicity, more preferably a flammability substantially less than the flammability of the refrigerant in the first heat transfer fluid and / Which is substantially less toxic than the toxicity of the refrigerant in the refrigerant.

In a preferred embodiment, the first heat transfer fluid comprises a refrigerant having a GWP of about 500 or less, the second heat transfer fluid also having a GWP of about 500 or less, and substantially less than the flammability of the refrigerant in the first heat transfer fluid Less flammability and / or a substantially lower toxicity than the toxicity of the refrigerant in the first heat transfer fluid.

In a preferred embodiment, the first heat transfer fluid comprises a refrigerant having a GWP of about 400 or less, the second heat transfer fluid also having a GWP of about 400 or less, and substantially less than the flammability of the refrigerant in the first heat transfer fluid Less flammability and / or a substantially lower toxicity than the toxicity of the refrigerant in the first heat transfer fluid.

In a preferred embodiment, the first heat transfer fluid comprises a refrigerant having a GWP of about 150 or less, and the second heat transfer fluid also has a GWP of about 150 or less and is substantially less than the flammability of the refrigerant in the first heat transfer fluid Less flammability and / or a substantially lower toxicity than the toxicity of the refrigerant in the first heat transfer fluid.

In a preferred embodiment, the second refrigerant comprises trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd (E)), more preferably at least about 50% (E)) and at least about 75 wt% trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd (E)) and the first refrigerant is greater than the flammability of HCFO-1233zd , Preferably substantially greater flammability.

In a preferred embodiment, the second refrigerant comprises trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd (E)), more preferably at least about 75% (E)) and the first refrigerant is greater than the flammability of HCFO-1233zd (E), and the second refrigerant is greater than the flammability of HCFO-1233zd , Preferably substantially greater flammability.

1 is a generalized process flow diagram of a preferred embodiment of an air conditioning system according to the present invention.
2 is a generalized process flow diagram of another preferred embodiment of an air conditioning system according to the present invention.
3 is a generalized process flow diagram of another preferred embodiment of an air conditioning system in accordance with the present invention.
4 is a schematic view of a heat exchanger in accordance with an embodiment of the present invention.
5 is a generalized process flow diagram of another preferred embodiment of an air conditioning system capable of operating both cooling and heating according to the present invention.

In each of the implementations described herein, the system includes a first heat transfer composition comprising a first refrigerant and preferably a lubricant for the compressor, and a second heat transfer composition comprising a second refrigerant. (HCFO-1233zd (E)) or at least about 75% by weight, more preferably at least about 50% by weight, more preferably at least about 80% by weight of trans 1-chloro-3,3,3-trifluoropropene The second refrigerant comprising at least about 80% by weight of trans 1,3,3,3-tetrafluoropropene (HFO-1234ze (E)) is added to a low flammability and low toxicity refrigerant, preferably to ASHRAE Standard 34 Flammability and low toxicity refrigerants with Class A toxicity and Class 1 or Class 2 or Class 2L flammability. In a highly preferred embodiment, the second refrigerant comprises at least about 95% by weight of HFCO-1233zd (E), and in some embodiments essentially consists of or consists of HFCO-1233zd (E).

In a highly preferred embodiment, the second refrigerant comprises from about 95 wt.% To about 99 wt.% Pentacarbon saturated hydrocarbon, preferably one or more iso-pentane, n-pentane or neo- pentane, The combination of HFCO-1233zd (E) and pentane is in the form of an azeotropic composition.

In a highly preferred embodiment, the second refrigerant comprises about 85 wt% to about 90 wt% of trans 1,3,3,3-tetrafluoropropene (HFO-1234ze (E)) and about 10 wt% to about 15 wt % Of 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), and more preferably in some embodiments, about 88% by weight of trans 1,3,3,3- Tetrafluoropropene (HFO-1234ze (E)) and about 12% by weight of 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea).

In a highly preferred embodiment, the second refrigerant comprises greater than about 50 wt% to about 67.5 wt% of trans 1,3,3,3-tetrafluoropropene (HFO-1234ze (E)) and greater than about 9.7 wt% (E) of less than 50% by weight, more preferably about 67% by weight of trans 1,3,3,3-tetrafluoropropene (HFO-1234ze (E) 33% by weight HFCO-1233zd (E). Applicants have found that this preferred embodiment can unexpectedly provide a second refrigerant that is collectively non-flammable according to the ASHRAE Standard 34 (which measures the flammability of the initial vapor from a fraction of the mixture that can occur if leakage of refrigerant occurs) And also produces pressures in excess of about 1 bar in the indoor loop of the refrigerant system.

Those skilled in the art will appreciate that this embodiment of the present invention provides the advantage of using only relatively low (low toxicity and low flammability) low GWP refrigerants, which can be used in humans or other households that occupy a residential area, as is often the case in air conditioning applications. Making it highly desirable for use in close proximity to other animals.

Preferably, in a preferred embodiment, the first refrigerant may comprise one or more components that make the refrigerant less toxic and / or flammable than the second refrigerant, and all such first refrigerants are within the scope of the present invention do. For example, the first refrigerant may comprise HFC-32 (preferably in an amount from about 0 wt% to about 22 wt%), HFO-1234ze (preferably in an amount from about 0 wt% to about 78 wt% HFO-1234yf (preferably in an amount from about 0 wt% to about 78 wt%), and propane. The second heat transfer composition of the present invention, unlike the first heat transfer composition, generally does not contain a lubricant because the fluid does not need to pass through the compressor.

The first heat transfer composition also generally comprises a lubricant in an amount of from about 30 to about 50 weight percent of the heat transfer composition, based on the total weight of the refrigerant and any other components present in the system. Other optional components include a compatibilizing agent such as propane to aid in the compatibility and / or solubility of the lubricant. When present, such compatibilizers, including propane, butane and pentane, are preferably present in an amount of from about 0.5 to about 5 weight percent of the composition. As disclosed in U.S. Patent No. 6,516,837, which is incorporated herein by reference, combinations of surfactants and solubilizing agents may also be added to the compositions of the present invention to aid in oil solubility. (POE) and polyalkylene glycol (PAG), silicone oil, mineral oil, alkylbenzene (AB), and poly (alpha olefin) (PAO), which are used in cooling apparatuses using hydrofluorocarbon (HFC) Such commonly used cooling lubricants may be used with the refrigerant compositions of the present invention. A preferred lubricant is POE.

An implementation of the type illustrated in Figure 1

In the following description, components or elements of a system that may be generally the same or similar in different implementations are denoted by the same number or symbol.

One preferred air conditioning system, designated 10, is shown in Figure 1, wherein the dashed line represents the approximate boundary between the indoor and outdoor loops and includes compressor 11, condenser 12, intermediate heat exchanger 13, Valve 14 is located outdoors with any connected conduits 15 and 16 and other connections and associated equipment (not shown). An outdoor loop, sometimes referred to as a " high temperature refrigerant circuit ", preferably comprises a first heat transfer composition comprising a lubricant for the first refrigerant and the compressor, preferably a first heat transfer composition comprising one or more of the above- 1 heat transfer composition, at least a first refrigerant circulating in the circuit by conduits 15 and 16 and other associated conduits and equipment.

An indoor loop, sometimes referred to herein as a " low temperature refrigerant circuit ", preferably comprises at least a second heat transfer composition comprising a second refrigerant, Has at least one safety characteristic, such as flammability and toxicity, which is superior to the corresponding safety characteristic. In a highly preferred embodiment, the second refrigerant is preferably low enough to be designated as Class A in accordance with ASHRAE Standard 34, and also preferably has a flammability sufficiently low to have a Class 1 or 2L flammability rating. In a highly preferred embodiment, the second refrigerant comprises, preferably consists essentially of, and consists of, HFCO-1233zd, more preferably trans HFCO-1233zd. In another highly preferred embodiment, the second refrigerant comprises a combination of HFO-1234ze (E) and 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) In some implementations, and in some implementations. Those skilled in the art will readily appreciate that such implementations of the present invention may be used in locations close to humans or animals that occupy the residential area or in the conditioned space, and in the vicinity of humans or animals that may or may not be present in the residential or conditioned space, (Low toxicity and low flammability) low GWP refrigerant, such as HFCO-1233zd (E) and HFO-1234ze (E) / HFC-227ea, Will be recognized in light of the disclosure herein. Thus, the preferred configuration and selection of the refrigerant has many desirable characteristics such as capacity, efficiency, low GWP and low ODP, but at the same time makes them very disadvantageous and / or has a drawback in that the space Lt; RTI ID = 0.0 > and / or < / RTI > one or more characteristics that may prevent the use of it in close proximity to other animals. This combination provides an exceptional advantage in terms of all desirable characteristics for such a refrigerant system.

In a preferred embodiment, the first refrigerant comprises, for example, HFC-32 (preferably in an amount from about 0 wt% to about 22 wt%), HFO-1234ze (preferably from about 0 wt% to about 78 wt% ), HFO-1234yf (preferably in an amount from about 0 wt% to about 78 wt%), and propane.

The heat transfer fluid in the outdoor circuit generally comprises a lubricant for the compressor generally in an amount of from about 30 to about 50 weight percent of the heat transfer fluid and the remainder comprises the refrigerant and any other components that may be present. Other optional components include a compatibilizing agent such as propane to aid in the compatibility and / or solubility of the lubricant. When present, such compatibilizers, including propane, butane and pentane, are preferably present in an amount of from about 0.5 to about 5 weight percent of the composition. As disclosed in U.S. Patent No. 6,516,837, which is incorporated herein by reference, combinations of surfactants and solubilizing agents may also be added to the compositions of the present invention to aid in oil solubility. (POEs), polyalkylene glycols (PAGs), silicone oils, mineral oils, alkylbenzenes (ABs) and poly (alpha-olefins) (PAO), which are used in cooling systems using hydrofluorocarbon (HFC) May be used with the refrigerant compositions of the present invention. A preferred lubricant is POEs.

In operation, the second refrigerant according to the present invention circulates the circuit by flowing through the intermediate heat exchanger 13, where heat is transferred to the first refrigerant, whereby the second refrigerant is at least partially, preferably substantially, All of which are condensed in liquid form, which exits the intermediate heat exchanger through the circuit 17. In a preferred embodiment, the second refrigerant exiting the intermediate heat exchanger flows into the receiver 18 provided with the liquid reservoir of the second refrigerant. Although the receiver 18 is shown in the figure as being located indoors, it may be located outdoors, and it may be desirable to position the pump 20 outdoors, if present. The liquid refrigerant from the separation vessel is delivered to the evaporator through the conduit (21). 1, the liquid pump 20 is shown as facilitating the transfer of liquid refrigerant to the evaporator 24 through the conduits 21, 22 and the valve 23. However, in other implementations, the second refrigerant liquid may be delivered from the receiver, either alone or using other means or techniques that may be used in combination with the liquid pump. For example, in some implementations, transfer of the liquid refrigerant may be accomplished by using a gravity supply of liquid to the evaporator, while in other embodiments a thermal siphon arrangement may transfer the second liquid refrigerant to the evaporator 24) and from the evaporator to the intermediate heat exchanger (13).

In a preferred embodiment where the refrigerant consists of at least about 90% by weight, preferably essentially consists of, and preferably consists of HCFO-1233zd (E) or HFO-1234ze Corresponding:

The implementation of the type illustrated in Figure 2

Another preferred embodiment of the present invention is illustrated in Figure 2 in which a compressor 11, a condenser 12, an intermediate heat exchanger 13, an expansion valve 14, and a suction-line heat exchanger 30, (15A, 15B, 16A and 16B) and other connections and associated equipment (not shown). An outdoor loop, sometimes referred to as a " high temperature refrigerant circuit ", preferably comprises a first heat transfer composition comprising a first refrigerant and a lubricant for the compressor, And 22) and other associated conduits and equipment.

The inner loop is configured substantially the same as described above with respect to the inner loop of Figure 1, and the first and second heat transfer compositions are also preferably as shown elsewhere herein.

In operation, the first refrigerant according to the present invention is discharged from the compressor 11 as a relatively high pressure refrigerant vapor, which may contain the incorporated lubricant, and then enters the condenser 12 to transfer heat to ambient air, preferably to ambient air And is at least partially condensed. The refrigerant effluent from the condenser 12 is conveyed through the conduit 15A to the suction-line heat exchanger 30 where it loses additional heat from the intermediate heat exchanger 13 to the effluent. The effluent from the suction / liquid line heat exchanger 30 is then conveyed via conduit 15B to the expansion valve 14 where the pressure of the refrigerant is reduced, which again reduces the temperature of the refrigerant. The relatively cool liquid refrigerant from the expansion valve then enters the intermediate heat exchanger 13 where it obtains heat from the second refrigerant vapor leaving the evaporator 24 in the indoor loop. The first refrigerant effluent vapor from the intermediate heat exchanger is delivered to the suction / liquid line heat exchanger 30 via conduit 16A where it obtains heat from the condenser effluent from conduit 15A and, at high temperature, And is conveyed to the inlet of the compressor 11 by conduit 16B.

The evaporator effluent is transferred to the intermediate heat exchanger 13 via the receiver conduit 19 where it loses heat to the effluent from the suction line heat exchanger which is transferred to the intermediate heat exchanger via conduit 15B, Producing a relatively cold stream of refrigerant. This cold stream of secondary refrigerant from the intermediate heat exchanger 13 is transferred to a receiver tank 18 which provides a reservoir of cold liquid refrigerant which is transferred from the tank via conduit 21 and then sent to the control valve 23 To the evaporator (24). In some implementations, a pump 20 is provided to provide a flow of liquid to the control valve 23. The ambient air to be cooled loses heat to the cool liquid refrigerant in the evaporator 24, in turn evaporates the liquid refrigerant and generates the refrigerant vapor with little or no overheating, which is then returned to the intermediate heat exchanger 13 .

In a preferred embodiment wherein the refrigerant comprises, preferably consists essentially of, and preferably comprises at least about 90% by weight of HCFO-1233zd (E) or HFO-1234ze Corresponds to the indicated values:

An implementation of the type illustrated in Figure 3

Another preferred embodiment of the present invention is illustrated in Figure 3 and includes a two-stage compressor 11, a condenser 12, an intermediate heat exchanger 13, an expansion valve 14, and an associated intermediate expansion valve 41 A vapor-injection heat exchanger 40 is placed outdoors with any connected conduit 15A-15 and other connections and associated equipment (not shown). An outdoor loop, sometimes referred to herein as a " high temperature refrigerant circuit ", preferably includes a first heat transfer composition comprising a lubricant for the first refrigerant and the compressor, 16) and other associated conduits and equipment.

The inner loop is configured substantially the same as described above with respect to the inner loop of Figure 1, and the first and second heat transfer compositions are also preferably as shown elsewhere herein.

In operation, the first refrigerant according to the present invention, which may include an incorporated lubricant, is discharged from the compressor 11 as a relatively high-pressure refrigerant vapor, which may contain an incorporated lubricant, enters the condenser 12, Preferably to ambient air, and at least partially condenses. The effluent stream from the condenser 12 comprises a refrigerant that is at least partially, and preferably substantially completely condensed. The refrigerant effluent from the condenser 12 is transferred to the conduit 15A and a portion of the refrigerant effluent is transferred to the intermediate expansion device 41 via the conduit 15B and the remaining portion of the effluent, Is transferred to the steam injection heat exchanger (40).

The intermediate expansion device 41 reduces the pressure of the effluent stream, preferably substantially isoenthalpically, to approximately the second stage suction pressure of the compressor 11 or to the heat exchanger 41 and associated Through conduits, devices, etc., sufficiently to overcome such pressure to handle the pressure-drop. As a result of the pressure drop through the expansion device 41, the pressure of the refrigerant flowing into the heat exchanger 40 is reduced relative to the temperature of the high pressure refrigerant flowing into the heat exchanger 40. Heat is transferred from the high pressure strip in the heat exchanger to the stream passing through the expansion valve (41). As a result, the temperature of the intermediate pressure stream exiting the heat exchanger 40 is higher than the temperature of the inlet stream, thereby producing a superheated vapor stream that is conveyed via the conduit 19C to the second stage of the compressor 11.

As the high pressure stream delivered by the conduit 15A travels through the heat exchanger 40 it loses heat to the low pressure stream exiting the expansion device 41 and exits the heat exchanger through the conduit 15C, To the expansion device 14 and then to the intermediate heat exchanger where heat is obtained and transferred to the first stage of compressor suction.

In a preferred embodiment wherein the refrigerant comprises, preferably consists essentially of, and preferably comprises at least about 90% by weight of HCFO-1233zd (E) or HFO-1234ze Corresponds to the indicated values:

An implementation of the type illustrated in Figure 5

In the following description, components or elements of a system that may be generally the same or similar in different implementations are denoted by the same number or symbol.

The implementation disclosed in Figure 5 is similar to the implementation of Figure 1 except that a reversible valve is mounted such that the system can operate in a heating mode, as will be described below.

One preferred air conditioning system that is capable of operating in both the cooling and heating modes is shown in Figure 1 and is generally designated as 10, wherein the indicated lines represent approximate boundaries between indoor and outdoor loops and include compressor 11, The coil 12, the intermediate heat exchanger 13, the expansion valve 14, and the reversing valve 500 are located outdoors with any connected conduits 15 and 16 and other connections and associated equipment (not shown) . The outdoor loop preferably comprises a first heat transfer composition according to one or more of the preferred embodiments, preferably comprising a lubricant for the first refrigerant and the compressor, at least a first refrigerant is present in the conduits (15 and 16) and Circulated in the circuit by other relevant conduits and equipment.

The indoor loop preferably includes at least a second heat transfer composition comprising a second refrigerant wherein the second refrigerant has at least one safety characteristic such as flammability and toxicity that is superior to the corresponding safety characteristic of the first refrigerant . In a highly preferred embodiment, the second refrigerant is preferably low enough to be designated as Class A in accordance with ASHRAE Standard 34, and also preferably has a flammability sufficiently low to have a Class 1 or 2L flammability rating. In a highly preferred embodiment, the second refrigerant comprises, preferably consists essentially of, and consists of, HFCO-1233zd, more preferably trans HFCO-1233zd. In another highly preferred embodiment, the second refrigerant comprises a combination of HFO-1234ze (E) and 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) In some implementations, and in some implementations. Those skilled in the art will readily appreciate that such implementations of the present invention may be used in locations close to humans or animals that occupy the residential area or in the conditioned space, and in the vicinity of humans or animals that may or may not be present in the residential or conditioned space, (Low toxicity and low flammability) low GWP refrigerant, such as HFCO-1233zd (E) and HFO-1234ze (E) / HFC-227ea, Will be recognized in light of the disclosure herein. Thus, the preferred configuration and selection of the refrigerant has many desirable characteristics such as capacity, efficiency, low GWP and low ODP, but at the same time makes them very disadvantageous and / or has a drawback in that the space Lt; RTI ID = 0.0 > and / or < / RTI > one or more characteristics that may prevent the use of it in close proximity to other animals. This combination provides an exceptional advantage in terms of all desirable characteristics for such a refrigerant system.

In a preferred embodiment, the first refrigerant comprises, for example, HFC-32 (preferably in an amount from about 0 wt% to about 22 wt%), HFO-1234ze (preferably from about 0 wt% to about 78 wt% ), HFO-1234yf (preferably in an amount from about 0 wt% to about 78 wt%), and propane.

The heat transfer fluid in the outdoor circuit generally comprises a lubricant for the compressor generally in an amount of from about 30 to about 50 weight percent of the heat transfer fluid and the remainder comprises the refrigerant and any other components that may be present. Other optional components include a compatibilizing agent such as propane to aid in the compatibility and / or solubility of the lubricant. When present, such compatibilizers, including propane, butane and pentane, are preferably present in an amount of from about 0.5 to about 5 weight percent of the composition. As disclosed in U.S. Patent No. 6,516,837, which is incorporated herein by reference, combinations of surfactants and solubilizing agents may also be added to the compositions of the present invention to aid in oil solubility. (POEs), polyalkylene glycols (PAGs), silicone oils, mineral oils, alkylbenzenes (ABs) and poly (alpha-olefins) (PAO), which are used in cooling systems using hydrofluorocarbon (HFC) May be used with the refrigerant compositions of the present invention. A preferred lubricant is POEs.

In operation, the second refrigerant according to the heating mode embodiment of FIG. 5 of the present invention circulates the circuit by flowing through the intermediate heat exchanger 13, where it picks up heat from the first refrigerant, Partially, preferably substantially all, in vapor form, where it exits the intermediate heat exchanger via conduit 17. The vapor refrigerant is sent to the condenser via conduit 21, which rejects heat into the settlement as it condenses. 1, the liquid pump 20 is shown as facilitating the transfer of liquid refrigerant to the condenser 24 via the conduits 21, 22 and the valve 23. This indoor loop may also include a reversible valve 501 that allows the system to operate in both heating and cooling modes.

In a preferred embodiment, the refrigerant comprises, preferably consist essentially of, and preferably consists of at least about 90% by weight of HCFO-1233zd (E) or HFO-1234ze (E).

Example

Comparative Example 1

An air conditioning system according to a typical arrangement using R-410A as a refrigerant is operated according to the following parameters.

Operating conditions - R410A basic cycle

1. Condensing temperature = 45 ° C, corresponding outdoor ambient temperature = 35 ° C

2. Condensing temperature - Ambient temperature = 10 ℃

3. Expansion unit sub-cooling = 5.0 ° C

4. Evaporation temperature = 7 ℃, indoor room temperature = 27 ℃

5. Evaporator overheating = 5.0 ° C

6. Isentropic Efficiency = 72%

7. Volumetric efficiency = 100%

The capacity and the COP of this system are determined using the reference capacity as a reference value for determining the relative capacity and the COP in the following embodiments.

Example 1A

Example 1A (Fig. 1) Operating conditions

The system constructed here as shown in Figure 1 is operated in accordance with the following operating parameters using a series of different first (outdoor) and second (indoor) refrigerants:

1. Condensing temperature = 45 ° C, corresponding outdoor ambient temperature = 35 ° C

2. Condensing temperature - Ambient temperature = 10 ℃

3. Expansion unit sub-cooling = 5.0 ° C

4. Evaporation temperature = 7 ℃, indoor room temperature = 27 ℃

5. Evaporator overheat = 0.0 ° C (flooded)

6. Intermediate heat exchanger overheat = 5.0 ℃

7. Isentropic Efficiency = 72%

8. Volumetric efficiency = 100%

9. Saturation temperature Difference in intermediate heat exchanger = 5 ℃

The results are provided in Table 1A below (percent for blend is expressed in weight%):

Table 1A

As can be seen from the above results, each air conditioning system according to the present invention was able to provide accurate capacity matching with a conventional R410A air conditioning system operated as indicated, and in all cases compared to such conventional systems It was possible to provide a COP (efficiency) of at least 85%. Importantly, in all cases the system uses a refrigerant with a GWP of less than 150, which is improved by about 10 times that of a cooling system based on R-410A. The ability to achieve this combination of properties is very beneficial but unexpected.

Example 1B (Fig. 1) Operating conditions

The system configured as shown in FIG. 1 herein is a system configured as shown in FIG. 1, except that the condensation temperature is adjusted for each blend to obtain an efficiency substantially in accordance with the efficiency achieved according to Comparative Example 1, Outdoor) and the second (indoor) refrigerant. The results are provided in Table 1B below:

Table 1B

The above results show that it is possible to achieve a system according to the present invention that produces efficiencies substantially coinciding with the efficiency of the system based on R-410A, with only a relatively small change in the condenser temperature. Alternatively, the efficiency according to the method of the present invention provides a fine increase in the heat transfer area in the condenser as compared to the amount of heat transfer area in the condenser in which the comparative R-410A system is used, Preferably. In addition, the system according to FIG. 2 using a suction line heat exchanger shows an advantageous improvement in terms of efficiency compared to the configuration of the present invention without such a heat exchanger reported in Embodiment 1A.

Example 1C (Fig. 1) - Change in ambient conditions

The system configured as shown in Figure 1 uses a series of different first (outdoor) and second (indoor) refrigerants for each blend, except that the ambient temperature is adjusted to 35 캜, 45 캜 and 55 캜 Is operated in accordance with the same operation parameters as in Embodiment 1A. The results are provided in Table 1C below:

Table 1C

The above results show that as the ambient temperature rises above 35 [deg.] C, it can provide better performance than the R-410A system according to the implementation of the present invention.

Example 2A

Example 2A (Fig. 2) Operating conditions

The system constructed as shown here in FIG. 2 is operated in accordance with the following operating parameters using a series of different first (outdoor) and second (indoor) refrigerants:

1. Condensing temperature = 45 ° C, corresponding outdoor ambient temperature = 35 ° C

2. Condensing temperature - Ambient temperature = 10 ℃

3. Expansion unit sub-cooling = 5.0 ° C

4. Evaporation temperature = 7 ℃, indoor room temperature = 27 ℃

5. Evaporator overheat = 0.0 ° C (flooded)

6. Intermediate heat exchanger overheat = 5.0 ℃

7. Isentropic Efficiency = 72%

8. Volumetric efficiency = 100%

9. Saturation temperature Difference in intermediate heat exchanger = 5 ℃

The results are provided in Table 2A below (the percentages for the blend are expressed in weight%):

Table 2A

As can be seen from the above results, each air conditioning system according to the present invention was able to provide accurate capacity matching with a conventional R410A air conditioning system operated as indicated, and in all cases compared to such conventional systems It was possible to provide a COP (efficiency) of at least 90%. Importantly, in all cases the system uses a refrigerant with a GWP of less than 150, which is improved by about 10 times that of a cooling system based on R-410A. The ability to achieve this combination of properties is very beneficial but unexpected.

Example 2B

Example 2B (FIG. 2) - Change in condenser temperature

The system configured as shown in FIG. 2 herein has a series of different first (and second) blends, except that the condensation temperature is adjusted for each blend to obtain an efficiency substantially consistent with the efficiency achieved according to Comparative Example 1. [ Outdoor) and the second (indoor) refrigerant according to the same operating parameters as in Example 2A. The results are provided in Table 2B below:

Table 2B

The above results show that it is possible to achieve the system according to the invention which produces, with only a relatively small change in the condenser temperature, an efficiency which substantially coincides with the efficiency of the system based on R-410A. Alternatively, the efficiency according to the method of the present invention provides a fine increase in the heat transfer area in the condenser as compared to the amount of heat transfer area in the condenser in which the comparative R-410A system is used, Preferably.

Example 2C

Example 2C (Fig. 2) - Change in ambient conditions

A system configured as shown herein in FIG. 2 is a series of different first (outdoor) and second (indoor) refrigerants except that the ambient temperature is adjusted to 35, 45 and 55 degrees Celsius for each blend. Is operated according to the same operation parameters as in Example 2A. The results are provided in Table 2C below:

Table 2C

The above results show that as the ambient temperature rises above 35 [deg.] C, it can provide better performance than the R-410A system according to the implementation of the present invention.

Example 3A

Example 3A (Fig. 3) Operating conditions

The system configured as shown here in FIG. 3 operates in accordance with the following operating parameters using a series of different first (outdoor) and 100% trans HF-1233zd as room refrigerant:

1. Condensing temperature = 45 ℃, corresponding outdoor temperature = 35 ℃

2. Condensing temperature - Ambient temperature = 10 ℃

3. Expansion unit sub-cooling = 5.0 ° C

4. Evaporation temperature = 7 ℃, corresponding room temperature = 27 ℃

5. Evaporator overheat = 0.0 ° C (flooded)

6. Intermediate heat exchanger overheat = 5.0 ℃

7. Isentropic efficiency for both steps = 72%

8. Volumetric efficiency = 100%

9. Difference in saturation temperature in intermediate heat exchanger = 5 ℃

10. Steam Injection Heat Exchanger Effectiveness = 35%, 55%, 75%, 85%

The results are provided in Table 3A below (percent for blend is expressed in weight%):

TABLE 3A

As can be seen from the above results, each air conditioning system according to the present invention was able to provide accurate capacity matching with a conventional R410A air conditioning system operated as indicated, and in all cases compared to such conventional systems It was possible to provide a COP (efficiency) of at least 90%. Importantly, in all cases the system uses a refrigerant with a GWP of less than 150, which is improved by about 10 times that of a cooling system based on R-410A. The ability to achieve this combination of properties is very beneficial but unexpected.

Example 3B

Example 3B (FIG. 3) - Change in condenser temperature

The system constructed as shown here in FIG. 3 has a series of different < RTI ID = 0.0 > different < / RTI > different refrigerants as the room refrigerant except that the condensation temperature is adjusted for each blend to obtain efficiencies substantially in accordance with the efficiency achieved according to Comparative Example 1. & Was operated according to the same operating parameters as in Example 3A using the first (outdoor) and 100% trans HFCO-1233zd. The results are provided in Table 3B below:

Table 3B

The above results show that it is possible to achieve the system according to the invention which produces, with only a relatively small change in the condenser temperature, an efficiency which substantially coincides with the efficiency of the system based on R-410A. Alternatively, the efficiency according to the method of the present invention provides a fine increase in the heat transfer area in the condenser as compared to the amount of heat transfer area in the condenser in which the comparative R-410A system is used, Preferably.

Example 3C

Example 3C (FIG. 3) - Change in ambient conditions

A system constructed as shown in FIG. 3 herein is a system in which a series of different first (outdoor) and second (indoor) refrigerants, except ambient temperatures are adjusted to 35 ° C, 45 ° C and 55 ° C for each blend Is operated according to the same operation parameters as in Example 2A. The results are provided in Table 3C below:

The above results show that as the ambient temperature rises above 35 [deg.] C, it can provide better performance than the R-410A system according to the implementation of the present invention.

Example 4

The air conditioning system of Example 1 includes a variety of trans-HCFO-1233zd and trans HFO-1234ze using evaporator temperatures ranging from about -1 ° C to about 10 ° C, including the condenser temperatures commonly used in many important air- Lt; RTI ID = 0.0 > refrigerant. ≪ / RTI > The test results are shown in Table 4A below:

Table 4A

Applicants have found that a composition in which the amount of trans HFO-1234ze is at least about 50% by weight, as shown in Table 4 above, can be operated under a pressure greater than one atmosphere in an indoor circuit to avoid the need for a purge system, It has been found that it is possible to provide sufficiently low system pressure to enable the use of relatively low cost vessels and conduits and / or to advantageously prevent refrigerant leakage which may occur in high pressure systems. Applicants have also tested the flammability of the trans HFO-1234ze / trans HCFO-1233zd blend for fractional flammability associated with the flammability of the refrigerant upon leakage from the system, and the results of this operation are shown in Table 4B below:

Table 4B

Based on the results reported in Table 4B above, Applicant is flammable when the liquid blend with more than 67% by weight of trans HFO-1234ze is measured according to the fractionation test carried out according to ASTM 34, and according to the results in Table 4A, It has been found that an amount of trans HFO-1234ze (i.e., greater than 50% of trans HFCO-1233zd) in an amount less than about 50 wt% produces the potential for negative system pressure.

Example 5 - Compatibility with plastics useful in low pressure systems

Applicants have found that various plastic samples are immersed in trans HFCO-1233zd under ambient pressure conditions at room temperature (about 24 ° C-25 ° C) for two weeks, after which the sample is removed from trans HFCO-1233zd and outgas ) To test the stability of various plastic materials when exposed to trans HFCO-1233zd. The results are shown in Table 5 below:

As illustrated by the results of Table 5 above, the% change in average volume of each plastic material tested is less than 5%.

Example 6

The air conditioning system of Example 1 is characterized by a low temperature ratio according to ASHRAE 34, including any preferred low temperature refrigerant of the present invention including a refrigerant comprising HFO-1234ze (E), HFCO-1233zd (E) - It is operated under flammable refrigerant under the condition of inadvertent leakage of high temperature refrigerant which is A2L refrigerant. In this case, the A2L (weak flammable) refrigerant is mixed with the non-flammable cryogenic refrigerant in the event of careless leakage inside the intermediate heat exchanger. The resulting mixture of low temperature refrigerant (eg, R1233zd (E)) and A2L refrigerant may eventually leak into the interior. However, in many cases leakage into the interior will be non-flammable. In certain implementations, it is possible to ensure that the appropriate charge ratio is maintained between the higher and lower sides to ensure a non-flammable mixture using the accumulator with appropriate control. It may also be possible to include in the system of the present invention devices or devices capable of detecting the leakage of flammable refrigerant into an indoor loop and releasing all such refrigerant out of the house. One such leak detection system is disclosed in U.S. Application Serial No. 15 / 400,891 filed January 6, 2017 (see Figures 4A and 4B in particular), and Provisional Application No. 62 / 275,382 filed January 6, Each of which is incorporated herein by reference.

Table 6 shows the charge ratios that can prevent dangerous situations from occurring inside the residence when a leak accident occurs.

Table 6: Leakage in medium heat exchanger

Comparative Example 2

A typical prior art reversible heat pump system using R-410A as the refrigerant is operated in the heating mode according to the following parameters:

Operating conditions - R410A basic cycle

1. Condensation temperature = 40 ° C, indoor room temperature = 21.1 ° C

2. Condensing temperature - Ambient temperature = 19 ℃

3. Expansion unit sub-cooling = 5.0 ° C

4. Evaporation temperature = 0 ° C, corresponding outdoor ambient temperature = 8.3 ° C

5. Evaporator overheating = 5.0 ° C

6. Isentropic Efficiency = 72%

7. Volumetric efficiency = 100%

The capacity and COP of this system are determined using the baseline values for determining the relative capacity and the COP in the following Examples 7A and 7B according to the present invention.

Example 7A

The system constructed as shown here in FIG. 6 is operated in accordance with the following operating parameters using a series of different first (outdoor) and second (indoor) refrigerants:

1. Condensation temperature = 40 ° C, indoor room temperature = 21.1 ° C

2. Condensing temperature - Ambient temperature = 19 ℃

3. Expansion unit sub-cooling = 5.0 ° C

4. Evaporation temperature = 0 ° C, corresponding outdoor ambient temperature = 8.3 ° C

5. Evaporator overheat = 0.0 ° C (flooded)

6. Intermediate heat exchanger overheat = 5.0 ℃

7. Isentropic Efficiency = 72%

8. Volume efficiency = 100%

9. Saturation temperature Difference in intermediate heat exchanger = 5 ℃

The results are provided in Table 1A below (percent for blend is expressed in weight%):

Table 7A

As can be seen from the above results, each air conditioning system according to the present invention was able to provide accurate capacity matching with a conventional R410A air conditioning system operated as indicated, and in all cases compared to such conventional systems It was possible to provide a COP (efficiency) of at least 90%. Importantly, in all cases the system uses a refrigerant with a GWP of less than 150, which is improved by about 10 times that of a cooling system based on R-410A. The ability to achieve this combination of properties is very beneficial but unexpected.

Example 7B (Fig. 5) Operating conditions

A system constructed as shown in FIG. 5 herein is a system in which a series of different < RTI ID = 0.0 > different < / RTI > 1 (outdoor) and second (indoor) refrigerant. The results are provided in Table 7B below:

Table 7B

The above results show that it is possible to achieve a system according to the present invention that produces efficiencies substantially coinciding with the efficiency of the system based on R-410A, with only a relatively small change in the condenser temperature. Alternatively, the efficiency according to the method of the present invention provides a fine increase in the heat transfer area in the condenser as compared to the amount of heat transfer area in the condenser in which the comparative R-410A system is used, Preferably.

Claims (11)

A cooling system for cooling or heating air in a space occupied by a human using air in a space occupied by a human or cooling or heating an object located in a space occupied by the human being,
(a) As an outdoor refrigerant circuit
(i) an outdoor refrigerant having a GWP of less than about 500 flowing through at least a portion of the outdoor circuit to reject heat from the system or to absorb heat into the system, wherein the outdoor refrigerant At least the part of the outdoor circuit through which the refrigerant flows is not located in the space occupied by the human being;
(ii) a phase change heat exchanger;
(iii) a compressor providing a vapor stream of the outdoor refrigerant; And
(iv) an intermediate heat exchanger in which at least a portion of the outdoor refrigerant stream absorbs or rejects heat
An outdoor refrigerant circuit; And
(b) As an indoor refrigerant circuit
(i) an indoor refrigerant that flows through at least a portion of the indoor circuit to absorb heat from the space occupied by the human or to reject heat into a space occupied by the human, wherein the indoor refrigerant flows through the indoor circuit Wherein at least a portion of the interior circuitry is located within the space occupied by the human being, wherein the indoor refrigerant comprises at least about 50 weight percent HCFO-1233zd (E) and is (1) non-flammable according to ASHRAE Standard 34 (2) Occupational Exposure Limit (OEL) of more than 400 and classified as Class A by ASHRAE Standard 34; And (3) an indoor refrigerant having a GWP of less than about 500; And
(ii) the intermediate heat exchanger of the outdoor refrigerant circuit, wherein the outdoor refrigerant stream absorbs heat from the indoor refrigerant or rejects heat to the indoor refrigerant,
An indoor refrigerant circuit
≪ / RTI >
A cooling system for cooling air in a space occupied by a human using air in a space occupied by a human or cooling an article located in a space occupied by the human,
(a) As a high-temperature refrigerant circuit
(i) a high temperature refrigerant having a GWP of less than about 500 flowing through at least a portion of the high temperature refrigerant circuit to reject heat from the system, wherein at least the high temperature refrigerant flowing through the high temperature circuit Some of which are not located within the space occupied by the human;
(ii) a condenser to provide at least a first condenser effluent stream comprising a liquid high temperature refrigerant stream at a first temperature;
(iii) an expansion valve fluidly connected to the liquid high temperature refrigerant steam from the condenser, the expansion valve providing a high temperature refrigerant stream at a second temperature below the first temperature;
(iv) a compressor providing the condenser with a vapor stream comprising at least a portion of the refrigerant; And
(v) an intermediate heat exchanger from which the at least a portion of the hot refrigerant stream absorbs heat and generates a vapor stream comprising the hot refrigerant, wherein the vapor stream from the intermediate heat exchanger is in fluid communication with the inlet of the compressor A communicating, intermediate heat exchanger
A high temperature refrigerant circuit; And
(b) As a low-temperature refrigerant circuit
(i) a low temperature refrigerant flowing through at least a portion of the low pressure circuit to absorb heat from the space occupied by the human, wherein at least the portion of the low temperature circuit through which the low temperature refrigerant flows, Wherein the low temperature refrigerant comprises at least about 50% by weight of HCFO-1233zd (E) and is (1) non-flammable according to ASHRAE Standard 34, (2) an Occupational Exposure Limit (OEL)) and classified as Class A by ASHRAE Standard 34; And (3) a low temperature refrigerant having a GWP of less than about 500;
(ii) an accumulator containing at least a part of the low temperature refrigerant in a liquid state;
(iii) an evaporator fluidly connected to the accumulator to receive liquid low temperature refrigerant from the accumulator, thereby producing a low temperature refrigerant stream in a vapor state; And
(iv) the intermediate heat exchanger of the high temperature refrigerant circuit, wherein the high temperature refrigerant stream from the expansion valve absorbs heat from the low temperature refrigerant vapor from the evaporator, and the intermediate heat exchanger comprises a liquid Wherein the cold liquid effluent stream from the intermediate heat exchanger is in fluid communication with the inlet of the accumulator,
A low-temperature refrigerant circuit
≪ / RTI >
3. The method of claim 2,
Wherein at least a portion of the liquid from the accumulator is conveyed to the inlet of the evaporator by a thermo-syphon effect.
3. The method of claim 2,
Wherein the high temperature refrigerant comprises up to about 22% by weight of R-32.
3. The method of claim 2,
Wherein the high temperature refrigerant comprises up to about 78% by weight of R-1234ze or up to about 78% by weight of R-1234yf.
3. The method of claim 2,
Wherein the high temperature refrigerant comprises about 10 wt% to about 100 wt% of propane.
3. The method of claim 2,
Wherein the condenser is operated at a temperature in the range of about 35 < 0 > C to about 70 < 0 > C.
A cooling system for cooling air in a space occupied by a human using air in a space occupied by a human or cooling an article located in a space occupied by the human,
(a) As a high-temperature refrigerant circuit
(i) high temperature refrigerant flowing through at least a portion of the high pressure circuit to reject heat from the system, wherein at least the portion of the high temperature circuit through which the high temperature refrigerant flows through the high temperature circuit is within the space occupied by the human Not located, high temperature refrigerant;
(ii) a condenser to provide at least a first condenser effluent stream comprising a liquid high temperature refrigerant stream at a first temperature;
(iii) an expansion valve fluidly connected to the liquid high temperature refrigerant steam from the condenser, the expansion valve providing a high temperature refrigerant stream at a second temperature below the first temperature;
(iv) a compressor providing the condenser with a vapor stream comprising at least a portion of the refrigerant;
(v) an intermediate heat exchanger, wherein at least a portion of the hot refrigerant stream from the expansion valve absorbs heat and thereby produces a hot effluent stream comprising the hot refrigerant at a temperature above the temperature of the stream from the expansion valve, ; And
(vi) a suction line heat exchanger connected between the condenser and the expansion valve and between the intermediate heat exchanger and the compressor inlet, the suction line heat exchanger comprising: (1) the suction line heat exchanger having at least a portion of the liquid hot- Wherein heat is rejected from the liquid hot refrigerant steam before the stream enters the expansion valve; And (2) the suction line heat exchanger receives at least a portion of the hot refrigerant leaving the intermediate heat exchanger and absorbs heat from the liquid hot refrigerant steam from the condenser, wherein after the heat is absorbed, A suction line heat exchanger < RTI ID = 0.0 >
A high temperature refrigerant circuit; And
(b) As a low-temperature refrigerant circuit
(i) a low temperature refrigerant flowing through at least a portion of the low pressure circuit to absorb heat from the space occupied by the human, wherein at least the portion of the low temperature circuit through which the low temperature refrigerant flows, Wherein the low temperature refrigerant comprises at least about 50% by weight of HCFO-1233zd (E) and is (1) non-flammable according to ASHRAE Standard 34, (2) an Occupational Exposure Limit (OEL)) and classified as Class A by ASHRAE Standard 34; And (3) a low temperature refrigerant having a GWP of less than about 500;
(ii) an accumulator containing at least a part of the low temperature refrigerant in a liquid state;
(iii) an evaporator fluidly connected to the accumulator to receive liquid low temperature refrigerant from the accumulator, thereby producing a low temperature refrigerant stream in a vapor state; And
(iv) the intermediate heat exchanger of the high temperature refrigerant circuit, wherein the high temperature refrigerant stream from the expansion valve absorbs heat from the low temperature refrigerant vapor from the evaporator, and the intermediate heat exchanger comprises a liquid Wherein the cold liquid effluent stream from the intermediate heat exchanger is in fluid communication with the inlet of the accumulator,
A low-temperature refrigerant circuit
≪ / RTI >
9. The method of claim 8,
Wherein the high temperature refrigerant comprises at least one of R-32, R-1234ze, R-1234yf and propane.
9. The method of claim 8,
Wherein the condenser is operated at a temperature in the range of about 35 < 0 > C to about 70 < 0 > C.
3. The method of claim 2,
Further comprising a sensor for detecting the leakage of the high temperature refrigerant into the low temperature refrigerant and a low temperature refrigerant charge controller responsive to the sensor, wherein the low temperature refrigerant is supplied to the low temperature refrigerant in order to ensure that the low temperature refrigerant is maintained as non- And an additional amount is charged to the cryogenic cooling circuit.

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