TEMPERATURE-CONTROLLED SYSTEM WITH THERMALLY ISOLATED COMPONENTS

Abstract

Disclosed and described herein are example refrigeration units having an interior conditioned space and a refrigeration circuit charged with a refrigerant, such as an A3 refrigerant. The refrigeration circuit includes a compressor-condenser assembly that is thermally isolated from an ambient environment of the conditioned space. An air plenum structure may thermally isolate the compressor-condenser assembly from the ambient environment of the conditioned space and direct heated rejection from refrigeration system. In an operational configuration in which the refrigeration system is installed in a structure, the compressor-condenser assembly may be thermally isolated from the ambient environment of the conditioned space via at least a portion of the structure, such as by positioning the compressor-condenser assembly on an exterior wall of the structure and coupling the compressor-condenser with the refrigeration circuit and conditioned space through the wall.

Claims

1. A refrigeration system comprising: a conditioned space; and a refrigeration circuit configured to receive an A3 refrigerant, wherein the refrigeration circuit comprises: a compressor-condenser assembly comprising: a compressor configured to be coupled to the refrigeration circuit; and a condenser configured to be coupled to the refrigeration circuit, wherein at least a portion of the compressor-condenser assembly is thermally isolated from an ambient environment of the conditioned space.

2. The refrigeration system of claim 1, further comprising an air plenum structure configured to thermally isolate the compressor-condenser assembly.

3. The refrigeration system claim 2, wherein the air plenum structure is configured to substantially envelop the compressor-condenser assembly.

4. The refrigeration system of claim 2, wherein the compressor-condenser assembly is configured to be positioned at a top surface of the conditioned space, and the air plenum structure is configured to be attached to the top surface.

5. The refrigeration system of claim 4, further comprising an evaporator positioned within the conditioned space.

6. The refrigeration system of claim 4, wherein the air plenum structure is removably attached to the top surface of the conditioned space.

7. The refrigeration system of claim 4, wherein the attachment between the air plenum structure and the top surface is configured to substantially seal the compressor-condenser assembly within the air plenum structure.

8. The refrigeration system of claim 2, wherein the air plenum structure defines: at least one plenum input in fluid communication with an external environment of the air plenum structure; and at least one plenum output in fluid communication with the external environment of the air plenum structure.

9. The refrigeration system of claim 8, wherein the external environment of the air plenum structure is thermally isolated from the ambient environment of the conditioned space.

10. The refrigeration system of claim 8, wherein the air plenum structure defines a first air plenum input and a second air plenum input each of which are in fluid communication with the external environment of the air plenum structure.

11. The refrigeration system of claim 8, further comprising an exhaust fan coupled to the at least one plenum output, wherein the exhaust fan is configured to force heated air within the air plenum structure to the external environment.

12. The refrigeration system of claim 2, wherein a temperature within the air plenum structure is greater than a temperature of the external environment.

13. The refrigeration system of claim 1, wherein, in an operational configuration in which the refrigeration system is installed in a structure, the compressor-condenser assembly is thermally isolated from the ambient environment of the conditioned space via at least a portion of the structure.

14. The refrigeration system of claim 13, wherein the portion of the structure defines: a first surface proximate the conditioned space; and a second surface opposite the first surface proximate the compressor-condenser assembly.

15. The refrigeration system of claim 13, wherein the portion of the structure comprises an exterior wall of the structure.

16. The refrigeration system of claim 15, wherein the exterior wall defines: a first surface proximate the conditioned space; and a second surface opposite the first surface proximate the compressor-condenser assembly.

17. The refrigeration system of claim 16, where the compressor-condenser assembly is disposed in an external environment of the structure proximate the second surface.

18. The refrigeration system of claim 13, wherein the support structure defines one or more openings configured to at least partially receive a fluid line set therein, wherein the fluid line set is configured to provide fluid communication between compressor-condenser assembly and the conditioned space through the structure.

19. The refrigeration system of claim 1, wherein the compressor-condenser assembly and the refrigeration circuit comprise a full charge of the A3 refrigerant.

20. The refrigeration system of claim 1, wherein the compressor-condenser assembly further comprises: a first disconnect fitting coupling the compressor input to the refrigeration circuit; and a second disconnect fitting coupling the condenser output to the refrigeration circuit.

21. The refrigeration system of claim 20, wherein at least one of the first and the second disconnect fittings is a double shut-off quick disconnect fitting.

22. The refrigeration system of claim 1, wherein: the condenser further comprises a condenser output communicably coupled to a first end of a capillary tube; and the compressor further comprises a compressor input and a compressor output.

23. The refrigeration system of claim 22, further comprising an evaporator comprising an evaporator input and an evaporator output, wherein the evaporator input is communicably coupled to a second end of the capillary tube and the evaporator output is communicably coupled to a first end of a suction line, wherein at least a portion of the suction line and at least a portion of the capillary tube are thermally coupled.

24. The refrigeration system of claim 22, wherein the compressor input is communicably coupled to a second end of the suction line.

25. The refrigeration system of claim 22, wherein the compressor output is communicably coupled to the condenser.

26. The refrigeration system of claim 23, wherein the portion of the suction line and the portion of the capillary tube are adjacent or coupled to a heat exchanger.

27. The refrigeration system of claim 22, wherein the compressor input is communicably coupled to the suction line via a first disconnect fitting.

28. The refrigeration system of claim 21, wherein the condenser output is communicably coupled to the capillary tube.

29. The refrigeration system of claim 1, wherein the A3 refrigerant has a Global Warming Potential (GWP) value less than 10.

30. The refrigeration system of claim 1, wherein the refrigeration system further comprises a maximum charge of 5.3 ounces (150 grams) of the A3 refrigerant per compressor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Having described certain example embodiments of the present disclosure in general terms above, reference will now be made to the accompanying drawings. The components illustrated in the figures may or may not be present in certain embodiments described herein. Some embodiments may include fewer (or more) components than those shown in the figures.

[0055] FIG. 1 is a block diagram illustrating a refrigeration system, in accordance with one example of the present disclosure;

[0056] FIGS. 2A-2F are block diagrams illustrating examples of a thermal exchange configurations of the refrigeration system, in accordance with the present disclosure;

[0057] FIG. 3 illustrates a walk-in refrigeration unit, in accordance with one example of the present disclosure;

[0058] FIGS. 4A-4C illustrate detailed views of an exemplary group of system components, in accordance with one example of the present disclosure; and

[0059] FIG. 4D illustrates a detailed view of another exemplary group of system components, in accordance with one example of the present disclosure.

[0060] FIGS. 5A-5B illustrate example quick disconnect fittings, in accordance with an example of the present disclosure;

[0061] FIGS. 6A-6B illustrate an example air plenum structure, in accordance with an example. of the present disclosure;

[0062] FIG. 7 illustrates an example structural installation (e.g., operational configuration) of the refrigeration system with thermal isolation, in accordance with an example of the present disclosure; and

[0063] FIG. 8 illustrates a transportation configuration of an example refrigeration system of FIG. 7, in accordance with an example of the present disclosure.

DETAILED DESCRIPTION

Overview

[0064] Embodiments of the present disclosure are directed to a refrigeration system (e.g., a walk-in refrigeration unit) for a temperature-controlled area or conditioned space that may, in some embodiments, thermally isolate at least a portion of the components of the refrigeration circuit from the ambient environment of the conditioned space (e.g., the occupancy or interior of a structure). The presently disclosed refrigeration system provides for maximizing conditioned space in the conditioned area by allowing the condenser unit to be removably disconnected/connected from the refrigeration circuit for installation. As described hereinafter, a split refrigeration system (e.g., an example refrigeration system of the present disclosure) or a walk-in cooler or a freezer using an A3 refrigerant (e.g., R290 or the like) that would have little to no effect on global warming for mid-size and smaller walk-in refrigeration is provided. The presently disclosed refrigeration system utilizes a capillary tube for the expansion device. In one example, the presently disclosed refrigeration system (e.g., the split refrigeration system) minimize a dimension of the liquid line, or any means that leaves the outlet of the condenser and goes to a traditional expansion valve. By minimizing the liquid line and removing the thermal expansion valve, the charge amount in the condenser and the evaporator is increased. Thus, the present disclosure provides the refrigeration system more capacity with the regulated small amount of working refrigerant that is allowed. The presently disclosed system is an improvement over existing systems as no ductwork is added to reduce airflow as in conventional self-contained refrigeration systems.

[0065] Examples of the present disclosure are further directed to refrigeration systems which use A3 classified refrigerants (according to the UL60335-2-89) in a walk-in refrigeration unit. In one example, the refrigerant is R290 (i.e. propane), which is an ultra-low GWP (Global Warming Potential) refrigerant that, when used in refrigeration systems, both lowers the energy consumed and reduces global warming. Being that R290 is classified as a flammable refrigerant it is restricted in the amount that can be safely used in a refrigeration circuit. For example, the current charge limit R290 is 150 gm (5.3 oz) per compressor in the United States. This charge restriction typically limits the refrigeration capacity of systems employing R290 as a refrigerant. As such, there exists a need for increasing the refrigeration capacity of said systems without increasing the charge amount of refrigerant. Examples of the present disclosure are directed to a refrigeration system which utilizes a small diameter line, such as a capillary tube, rather than a conventional liquid line to increase the refrigeration capacity of a walk-in unit. Thus, the present disclosure provides a refrigeration system which is able reach a high refrigeration capacity while utilizing the environmentally-friendly A3 refrigerant, thereby achieving a reduced environmental impact compared to a conventional refrigeration system.

[0066] The presently disclosed system, in one example, includes a condenser configured to be positioned at the top of a conditioned space (e.g., on any exterior surface bounding the conditioned space), where the condenser is removably coupled to a refrigeration circuit. In one example, the condensers are removably coupled to a refrigeration circuit using quick disconnects (e.g., quick disconnect fittings or the like as defined herein). In one example, the presently disclosed system includes one or more evaporator units positioned within the conditioned space.

[0067] Still further, and as described more fully hereinafter, the embodiments of the present disclosure may operate to thermally isolate at least a portion of the components of the refrigeration circuit, such as the removably attached compressors and condensers. By way of an example, in some embodiments, the refrigeration systems described herein may include an air plenum structure that is secured over or otherwise envelopes a compressor-condenser assembly. In particular, an example compressor-condenser assembly may be positioned at a top surface of the conditioned space (e.g., on an exterior surface of the housing bounding the condition space), and the air plenum structure may be attached to the top surface of the conditioned space such that the compressor-condenser assembly is disposed therein. The heated rejection of the compressor-condenser assembly may be exhausted to an external environment of the air plenum that is further thermally isolated from the ambient environment of the conditioned space. In other words, the ambient environment of the conditioned space may refer to the occupancy or interior of a structure within which the refrigeration system operates, such that the thermally isolated external environment of the air plenum structure may refer to an environment that is external to this occupancy (e.g., outside).

[0068] In other embodiments, as described herein, the compressor-condenser assembly may be positioned on an exterior surface of a structure within which the refrigeration system is installed (e.g., on an exterior wall of a structure in an external environment). For example, in an operational configuration in which the refrigeration system is installed in a structure (e.g., kitchen or the like), the compressor-condenser assembly may be thermally isolated from the conditioned space by at least a portion of the structure. Said differently, the exterior wall of the structure may support the conditioned space (e.g., the interior of the split walk in refrigeration system) on an interior of the structure while the compressor-condenser assembly is supported by an exterior of the structure. In doing so, the embodiments of the present disclosure may operate to remove or otherwise reduce the thermal burden (e.g., the heated rejection) generated by the operation of compressor-condenser assembly that would normally be experienced by the occupancy or interior of the structure.

Definitions

[0069] Examples of the present disclosure now may be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, examples of the disclosure are shown. Indeed, the disclosure may be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these examples are provided so that this disclosure may satisfy applicable legal requirements. Like numbers refer to like elements throughout.

[0070] It should be understood that communicably coupled, as used herein, encompasses components that are formed integrally with each other, or are formed separately and coupled together, for example, to allow the flow of refrigerant and/or heat. Furthermore, communicably coupled encompasses components that are formed directly to each other, or to each other with one or more components located between the components that are communicably coupled together. Furthermore, communicably coupled encompasses components that are detachable from each other, or that are permanently coupled together. Furthermore, communicably coupled components encompasses components that retain at least some freedom of movement in one or more directions or may be rotated about an axis (e.g., rotationally coupled, pivotally coupled) when disconnected, whereas when connected, restricted or no movement in one or more directions of the components can occur.

[0071] Given the nature of the refrigeration operations described herein, the terms communicably coupled as used herein may refer to the fluid communication between the components, devices, etc. forming or otherwise removably attached with the refrigeration circuits. As such, the present disclosure contemplates that the components described herein (e.g., the compressor, the condenser, the evaporator, the suction line, the capillary tube, etc.) may leverage any conduit, channel, tubing, line set, and/or the like through which a fluid may flow. Similarly, the connections between these components, such as those that are established via disconnect fittings (e.g., double shut-off quick disconnect fittings or the like), may also be configured to establish fluid communication that prevents or otherwise minimizes the leakage of the refrigerants therein.

[0072] As used herein, the phrase conditioned space or temperature-controlled space) is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning) and refers without limitation to any implementation that at least partially controls, manages, or otherwise impacts the thermal condition of an area. By way of example, a refrigeration system as described herein may include or otherwise define a conditioned space within which objects (e.g., food items or the like) may be positioned where the temperature of the conditioned space is controlled by the components of the refrigeration system. By way of example, the refrigeration systems described herein may be split refrigeration systems operating as a walk-in refrigeration unit. Although described herein with reference to a refrigeration system defining the conditioned space, the present disclosure contemplates that embodiments described herein may be applicable to any space for which the temperature is controlled.

[0073] Thermally coupled or in thermal communication as used herein encompasses components that are directly or indirectly coupled so as to facilitate heat transfer between the components. Said heat transfer encompasses any type of heat transfer including radiation, conduction, convection, phase changes, and the like. Furthermore, thermally coupled encompasses components where a temperature change of one component affects a temperature of another component. Furthermore, thermally coupled encompasses any connection, coupling, link, or the like between components such that heat from one component is imparted to another component (e.g., any components between which heat is transferred).

[0074] As used herein, the terms thermally isolated, thermal isolation, and thermally isolate refer to the components for which the heat transfer, relative thermal burden, etc. between these component is eliminated or otherwise reduced. By way of example, components that are thermally isolated may, in some embodiments, be physically removed or otherwise distanced from one another such that the heat and associated temperature of one thermally isolated component has little to no impact on the heat and associated temperature of the other thermally isolated component. As described herein, such as with reference to an example air plenum structure, thermal isolation may not require that components be physically isolated. For example, in such an implementation, thermal isolation may refer to components that may be thermally coupled components but for which the thermal burden and/or heat exchange is reduced. Said differently, the thermal isolation between thermally coupled components may refer to the dissipate of heat associated with one or more of the thermally coupled components so as to reduce the thermal burden of the other of the thermally coupled component or associated environment.

[0075] Ambient environment of the conditioned space as used herein refers to an environment that is proximate the exterior of the conditioned space. By way of example, the refrigeration system describes herein may be a walk-in refrigeration unit that is installed in the interior of a building or other structure, such as a kitchen. In such an example embodiment, the ambient environment may refer to the interior or occupancy of this building or structure for which the temperature is not maintained by the refrigeration system (e.g., the occupancy may be air conditioned but is separate from the refrigeration systems described herein). The embodiment described herein may thermally isolate various components of the refrigeration circuit so as to reduce the thermal burden on the occupancy or interior of these buildings or structure (e.g., the example ambient environments).

[0076] As used herein, external environment may refer to the environment that is in fluid communication with the interior of the air plenum structure described hereinafter but that is further thermally isolated from the ambient environment of the conditioned space. For example, the air plenum structures described herein may include various conditions, channels, etc. through which the heated rejection from the compressor-condenser assembly may be directed to an external environment that is external to the structure within which the refrigeration system is installed. In other words, the external embodiments of the air plenum structure described herein may refer to any location that is thermally isolated or otherwise separate from the occupancy or interior of the structure (e.g., the ambient environment of the conditioned space).

[0077] As used herein, the term fluid is inclusive of gaseous, liquid, and combinations of gas and liquid medium unless specifically designated as limited to a particular medium.

[0078] As used herein, the terms quick-disconnector, quick connectors, quick-disconnect, quick connect, quick release couplings, quick disconnect fittings, disconnect fittings, multiple line quick disconnector, or multiple line quick disconnect, (hereinafter referred to as QD, QDC or their plural forms) are broad terms, and are to be given their ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to snap type (ball latching), non-latching, single shut-off, double shut-off, or dry break couplings operable by one or two hands. In one example, the quick disconnect fittings of the present disclosure include shut-off valves within both the internal and external ends so as to retain pressure in the components in fluid communication via the quick disconnect fittings. By way of example, quick disconnect fittings described herein may be used as an attachment mechanism for an example compressor-condenser assembly such that the pressure within the fluid lines in fluid communication with (e.g., communicably coupled with) the compressor-condenser assembly is maintained.

[0079] The phrase distal to as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning) and refers without limitation to the spatial relationship between various elements in comparison to a particular point of reference, such as opposite a proximal to reference.

[0080] The term coupled as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning) and refers without limitation to two or more system elements or components that are configured to be at least one of electrically, mechanically, thermally, fluidically, operably, or otherwise attached. Similarly, the phrases operably connected, operably linked, and operably coupled as used herein may refer to one or more components linked to another component(s) in a manner that facilitates transmission of fluid, heat, current, or electrical signals between the components. In some examples, components are part of the same structure and/or integral with one another (e.g., directly coupled). In other examples, components are connected via remote means. For example, one or more temperature probes may be used to detect temperatures at different locations and convert that information into a signal; the signal may then be transmitted to an electronic circuit. In this example, the temperature probe is operably linked to the electronic circuit.

[0081] The terms removably coupled as used herein may refer to two or more system elements or components that are configured to be or have been electrically, mechanically, thermally, fluidically, operably, chemically, or otherwise attached and detached without damaging the coupled elements or components. For example, one or more fluid lines may be removably coupled with quick disconnect fittings as described herein. In such an example, the fluid lines are communicably coupled (e.g., in fluid communication with one another). The phrase permanently coupled as used herein may refer to two or more system elements or components that are configured to be or have been electrically, mechanically, thermally, fluidically, operably, chemically, or otherwise attached but cannot be uncoupled without damaging at least one of the coupled elements or components. As described hereinafter, at least a portion of the components of the refrigeration system may be removably coupled via quick disconnect fittings. By way of example, a compressor-condenser assembly may be configured to be removable coupled with a refrigeration circuit of a refrigeration system (e.g., by quick disconnect fittings), such that the compressor-condenser assembly may be installed on site (e.g., at the installation of the refrigeration system) while maintaining a charge of refrigerant within the system (e.g., within the combined compressor-condenser and refrigeration circuit). In some embodiments, the terms reversibly coupled may be used interchangeably with removably coupled. Additionally or alternatively, in some embodiments, the terms reversibly coupled may be used to refer to the ability for the flow direction within the refrigeration circuit to be reversed based on the connection between the components.

Example Refrigeration Systems

[0082] As described herein, embodiments of the present disclosure are directed to refrigeration systems that use refrigerants or A3 classified refrigerants, such as those used in refrigeration system, walk-in refrigeration implementations, and/or the like (according to the UL60335-2-89 standard for safety with flammable refrigerants or the like). In one example, the A3 refrigerant is R290 (i.e., propane), which is an ultra-low GWP (Global Warming Potential) refrigerant that, when used in refrigeration systems, both lowers the energy consumed and reduces global warming. Given that R290 is classified as a flammable refrigerant, the amount of refrigerant that may be safely used in a refrigeration circuit is limited (e.g., by applicable regulations). In the United States, for example, the current charge limit for R290 is 150 gm (5.3 oz) per compressor (without leakage detection and ventilation). Said differently, an example refrigeration system may include 150 grams (5.3 oz) of R290 refrigerant without having to employ costly leakage detection and ventilation systems. This charge restriction typically limits the refrigeration capacity of systems employing R290 as a refrigerant. As such, there exists a need for increasing the refrigeration capacity of said systems without increasing the charge amount of refrigerant for refrigeration systems employing R290 as a refrigerant.

[0083] In some embodiments, the refrigeration systems described herein may utilize a capillary tube for the expansion device. In one example, the presently disclosed refrigeration system is configured to minimize the liquid line, or any means that leaves the outlet of the condenser and goes to a traditional expansion valve. By minimizing the liquid line, the charge amount in the condenser and the evaporator is increased. Said differently, the refrigeration circuit of the systems described herein may include a suction line and a capillary tube functioning as at least a portion of the liquid line so as to minimize the dimensions (e.g., length or the like) of the liquid line. In doing so, these systems may operate to minimize volume capacity using top-mounted condensers without exceeding the maximal amount of R290 permitted without leakage detection and ventilation as described above.

[0084] FIG. 1 provides a block diagram illustrating the refrigeration system 100, in accordance with one example of the present disclosure. The refrigeration system 100 is configured for use in a refrigeration unit, such as a walk-in refrigeration unit. As used herein, a refrigeration unit may refer to any refrigerated device or appliance configured to maintain a temperature-regulated environment within an interior storage space or compartment (e.g., a conditioned space). In an example, the interior storage space is separated from the exterior space via a wall or barrier 120, wherein one or more components of the refrigeration system 100 are configured to pass through the barrier 120, as described in greater detail with respect to FIG. 3. In an example, components of the refrigeration system 100 are integrated into a single self-contained system. FIG. 1 depicts a source of power 102 connected in series with a controller 104. In an example, the source of power 102 includes any direct current (DC) or alternating current (AC) voltage source (e.g., a generator, battery, fuel cell, and/or the like) configured to provide power to components of the refrigeration system 100.

[0085] FIG. 1 further depicts a compressor 114 communicably coupled to an input of a condenser 110, collectively referred to as the compressor-condenser assembly. The input of the condenser 110 leads to an output that is communicably coupled to an input of an evaporator 112 via the capillary tube 118. The input of the evaporator 112 leads to an output that is communicably coupled to the compressor 114. The capillary tube 118 is communicably coupled to the output of the evaporator 112 at a heat exchanger 116. A condenser fan 106 is positioned near the condenser 110 and an evaporator fan 108 is positioned near the evaporator 112. The controller 104 and the source of power 102 are communicably coupled to the compressor 114.

[0086] Generally, the refrigeration system 100 includes a source of power 102, a controller 104, at least one condenser fan 106, at least one evaporator fan 108, a single or shared condenser 110, a single or shared evaporator 112, at least one compressor 114, at least one heat exchanger 116, and at least one capillary tube 118. In one example, a source of power 102 comprises any direct current (DC) or alternating current (AC) voltage source capable of providing power to the system components 104, 106, 108, 110, 112, 114, 116, and 118. In one example, the controller 104 may be any ignition-proof electronic controller configured to provide logic and decisioning for the system 100. In one example, the controller may be configured to activate the compressor 114. In some examples, the presently disclosed system may comprise multiple compressors 114 and may therefore include a controller configured to activate each compressor 114 sequentially, for example, for avoiding an excessive surge in amperage which would result from each compressor 114 activating simultaneously. For example, the controller may be configured to activate each compressor 114 sequentially based on a sensed temperature, a change in temperature, a manual input, or an event exceeding or falling below a temperature threshold.

[0087] In an example, the refrigeration system 100 is configured to receive a refrigerant (not shown). The liquid refrigerant is configured to pass into an input of the evaporator 112. The at least one evaporator fan 108 may be positioned near the evaporator 112 and is configured to direct atmospheric air over the evaporator 112, causing evaporation of the liquid refrigerant.

[0088] In one example, the compressor 114 is configured to pull cold, low-pressure gaseous refrigerant from the evaporator 112 into a compressor input. In some examples, the compressor 114 pulls the cold refrigerant through the suction line 113, thermally coupled to capillary tube 118. The compressor 114 then raises the temperature and pressure of the refrigerant and outputs the heated refrigerant into an input of the condenser 110. In one example, the at least one condenser fan 106 is positioned near the condenser 110 and is configured to direct atmospheric air over the condenser 110, causing the refrigerant to cool from a gaseous state to a liquid state. The refrigerant then flows through the capillary tube 118 from an output of the condenser 110 into an input of the evaporator 112 for evaporative cooling. Before reaching the input of the evaporator 112, the cooled refrigerant in the capillary tube 118 is introduced to heat exchanger 116 as described in greater detail with respect to FIG. 2. In an example, heat exchanger 116 comprises the capillary tube 118 and suction line 113 in a thermally coupled relationship. In an example, heat exchanger 116 comprises the capillary tube 118 and suction line 113 in a thermally coupled relationship with a conductive material such as copper, aluminum, stainless steel, and/or combinations thereof. In an example, heat exchanger 116 comprises a length of the capillary tube 118 and a length of the suction line 113 soldered together which functions as heat exchanger 116. The length and/or composition of solder for thermally coupling the capillary tube 118 and the suction line 113 can be determined based on an efficiency threshold or other system parameters. The dimensions (e.g., length, diameter, etc.) of the capillary tube 118 may be selected or otherwise determined with respect to at least one of compressor 114 specifications, among other specifications, using techniques known in the art.

[0089] In some examples, the system 100 comprises a plurality of compressors 114 connected to a shared source of power. In some examples, the system 100 comprises a plurality of expansion devices or capillary tubes 116 connected in parallel between the outputs of the condenser 110 and the inputs of the evaporator 112. Examples of such systems are found in co-assigned U.S. Pat. No. 11,859,885.

[0090] As described herein, the refrigeration system 100 may be configured for use in a walk-in refrigeration unit. In one example, a single refrigeration system 100 is sufficient to provide the total refrigeration capacity of the walk-in refrigeration unit, or alternatively, multiple systems 100 are installed in order to provide sufficient refrigeration capacity. In one example, refrigeration system 100 is configured within the refrigeration unit (e.g., the refrigeration system may include the conditioned space) such that the condenser 110 and at least one condenser fan 106 are positioned outside of the temperature-regulated space or environment (e.g., outside the conditioned space). In another example, evaporator 112 and at least one evaporator fan 108 are positioned inside of the temperature-regulated space or environment (e.g., conditioned space). In one example, the condenser 110 and condenser fan 106 are separated from the evaporator 112 and evaporator 108 via a wall or barrier 120.

[0091] In some examples, as described above, the system 100 is configured to receive a refrigerant having a GWP (Global Warming Potential) value less than 10. Specifically, the system 100 is configured to receive R290 refrigerant (i.e. propane), which has a GWP value of 3. The current charge limit for R290 is 150 gm (5.3 oz) per compressor in the United States, and therefore the system 100 is configured to receive a charge less than 5.3 oz of R290 refrigerant per compressor.

[0092] FIGS. 2A-2F illustrate detailed views of examples of the heat exchanger 116 of the refrigeration system 100. In FIG. 2A, both the capillary tube 118 and suction line 113 are configured to pass through the heat exchanger 116. In an example, the capillary tube 118 is configured to carry refrigerant in a first direction 202 from the outside condenser 110 to the inside evaporator 112. The suction line 113 is configured to carry refrigerant in a second direction 204 from the inside evaporator 112 to the outside compressor 114, i.e. in a direction opposite to the first flow direction 202. In an example, the pressure drop across the capillary tube 118 causes heated, liquid refrigerant to flash to a partially gaseous and partially liquid mixture. In one example, the capillary tube 118 is connected to the suction line 113 via heat exchanger 116, whereas this heat exchange drops the temperature of the refrigerant even further at or near the entrance of the evaporator, thus, increasing the refrigeration capacity of the system.

[0093] In one example, at the heat exchanger 116, the capillary tube 118, and suction line 113 are directly coupled to allow for heat transfer between the cool refrigerant in the capillary tube 118 and the heated refrigerant in the suction line 113. In one example, at the heat exchanger 116, the capillary tube 118 and suction line 113 are indirectly coupled to allow for heat transfer between the cool refrigerant in the capillary tube 118 and the heated refrigerant in the suction line 113. In some examples, the heat exchanger 116 comprises portions of the capillary tube 118 and suction line 113 being temporarily or permanently affixed together (e.g., by soldering and/or the like). The cooled refrigerant and the heated refrigerant flow in opposite directions 202 and 204, thereby increasing the temperature differential between the refrigerants as they exit the heat exchanger 116.

[0094] FIGS. 2B-2E illustrate exemplary configurations of thermal coupling between the capillary tube 118 and suction line 113. In FIG. 2B, the capillary tube 118 and suction line 113 are in thermal communication via a single thermally conductive element 117, which includes, but is not limited to solder, metal-containing tape or physical structures that radiantly or inductively transfer heat from the suction line 113 to the capillary tube 118. In FIG. 2C, the capillary tube 118 and suction line 113 are in thermal communication via two thermally conductive elements 121 and 122. In FIG. 2D, the capillary tube 118 and suction line 113 are in thermal communication via a thermally conductive element 123 comprising an X-shaped cross section. In FIG. 2E, the capillary tube 118 and suction line 113 are in thermal communication via the capillary tube 118 being coiled around the exterior or the suction line 113. In another example, capillary tube 118 and suction line 113 are in thermal communication via the capillary tube 118 being coiled inside the outer perimeter of suction line 113. In one example, thermally conductive material is adjacent to both the suction line 113 and the capillary tube 118 and a thermally insulating material at least partially surrounds the thermally conductive material.

[0095] In one example, the heat exchanger 116 may be a double pipe heat exchanger, shell and tube heat exchanger, plate heat exchanger, and/or any other suitable configuration. For example, FIG. 2F illustrates a shell and tube heat exchanger 116, comprising a capillary tube inlet 206, a capillary tube outlet 208, a suction line inlet 210, a suction line outlet 212, a plurality of tubes 214, and a plurality of baffles 216. The heated refrigerant 204 flows from the suction line inlet 210 through the plurality of tubes 214 and exits the heat exchanger 116 at the suction line outlet 212. Similarly, the cooled refrigerant 202 flows from the capillary tube inlet 206, passes over and around the plurality of tubes 214, and exits the heat exchanger 116 at the capillary tube outlet 208. In an example, the heat exchanger 116 comprises a plurality of baffles 216 configured to introduce turbulence to the cooled refrigerant 202, thereby increasing the temperature differential between the refrigerants 202 and 204 as they exit the heat exchanger 116.

[0096] FIG. 3 illustrates a temperature-regulated environment 300 (e.g., a walk-in refrigeration unit that includes the refrigeration system 100), in accordance with an example of the present disclosure. The temperature-regulated environment 300 comprises a door or entryway 301 and a barrier 120 (e.g. a wall, ceiling, roof, and/or the like). A first group of system components 101 is positioned inside of the temperature-regulated environment 300 and a second group of system components 103 is positioned outside of the temperature-regulated environment 300. As described above, the second group of system components 103 may include the compressor-condenser assembly. In an example, the first group of system components 101 and the second group of system components 103 may form the refrigeration circuit described herein. In an example, the temperature-regulated environment 300 includes additional groups of system components in order to increase the overall refrigeration capacity of the refrigeration system 100. In an example, the first group of system components 101 and the second group of system components 103 are coupled together via the capillary tube 118 and suction line 113 as described with respect to FIG. 1. In an example, the capillary tube 118 and suction line 113 are configured to pass through a hole, aperture, or passage in the barrier 120.

[0097] Although illustrated as a substantially rectangular conditioned space in FIG. 3, the present disclosure contemplates that the dimensions (e.g., size and shape) of the conditioned space associated with the environment 300 may vary based on the intended application of the refrigeration system 100. In one example, the space (e.g., conditioned spaced) regulated within the temperature-regulated environment 300 may be configured to maintain a temperature at or above the freezing point of water at a fixed altitude or barometric pressure range (e.g., avoiding a temperature at which water freezes). In one example, the space regulated within the temperature-regulated environment 300 may be configured to maintain food at a temperature at or above the freezing point of water at a fixed altitude or barometric pressure range.

[0098] FIGS. 4A-4C illustrate a detailed view of the exemplary group of system components 101. In one example, the group of system components 101 comprises a unit cooler or fan-coil combination unit. FIG. 4A illustrates a front view of the group of system components 101, comprising a front vent 401, the capillary tube 118, and the suction line 113. FIG. 4B illustrates a back view of the group of system components 101, comprising the evaporator 112, evaporator fan 108, capillary tube 118, and suction line 113. FIG. 4C illustrates a detailed view of the capillary tube 118 and suction line 113 in various thermally coupled to form the heat exchanger 116.

[0099] FIG. 4D illustrates a detailed view of another exemplary group of system components 103. In an example, the group of system components 103 comprises a compressor 114, condenser 110, and compressor fan 106 (e.g. the compressor-condenser assembly). In an example, the group of system components 103 is coupled to the group of system components 101 via the capillary tube 118 and suction line 113. The capillary tube 118 and suction line are in thermal communication, forming the heat exchanger 116. In an example, the group of system components 103 further comprises a dryer 501 configured to remove moisture from the system 103 (e.g., a filter dryer, liquid trap, reservoir, and/or the like). In an example, the group of system components 103 further comprises a liquid injection valve 503 configured to modulate the flow of liquid refrigerant 204 into the compressor 114, thereby cooling the compressor 114 and preventing or reducing compressor 114 overheating.

Example Quick Disconnect Fittings

[0100] With reference to FIGS. 5A-5B, example disconnect fittings 505 of the present disclosure are illustrated. As described above, the first group of system components 101 and the second group of system components 103 may collectively form the refrigeration circuit described herein. As shown, the compressor-condenser assembly 103 (e.g., the second group of system components) may include a first disconnect fitting 509 coupling the input of the compressor 114 to the refrigeration circuit 20, and a second disconnect fitting 507 coupling the output of the condenser 110 to the refrigeration circuit. In some examples, the input of the compressor 114 is communicably coupled to the suction line 113 via the first disconnect fitting 116. In some embodiments, the output of the condenser 110 is communicably coupled to the capillary tube 118 via the second disconnect fitting 507. As described above, the first and the second quick disconnect fittings 509, 507 may include, without limitation, any snap type (ball latching), non-latching, single shut-off, double shut-off, or dry break couplings operable by one or two hands. In one example, the quick disconnect fittings 505 of the present disclosure include shut-off valves within both the internal and external ends so as to retain pressure in the components in fluid communication via the quick disconnect fittings. As would be evident to one of ordinary skill in the art in light of the present disclosure, the fitting type defined by the compressor-condenser assembly 103 may be complimentary to the fitting type defined by the capillary tube 118/suction line 113 (e.g., a male to female connection scheme).

[0101] As described herein, the quick disconnect fittings 505 of the present disclosure may be used as an attachment mechanism for an example compressor-condenser assembly 103 (e.g., the second group of system components) such that the pressure within the fluid lines in fluid communication with (e.g., communicably coupled with) the compressor-condenser assembly is maintained and the charge of the refrigerant within the same is maintained. As shown, the refrigeration system 100 may utilize a capillary tube 118 for the expansion device so as to minimize the dimensions (e.g., length or the like) of the liquid line 124. In doing so, these systems may operate to minimize volume capacity using top-mounted condensers without exceeding the maximal amount of R290 permitted without leakage detection and ventilation as described above. Furthermore, as described hereinafter, the quick disconnect fittings 505 of the present disclosure may, in some embodiments, be used in conjunction with the thermal isolation features described herein. Said differently, the quick disconnect fittings 505 may be used in conjunction with the air plenum structure 600 of FIGS. 6A-6B and/or in the structure-based thermal isolation implementation 300 of FIGS. 7-8.

Example Thermal Isolation Implementations

[0102] With reference to FIGS. 6A-6B, an example air plenum structure 600 for use with the refrigeration systems 100 of the present disclosure is illustrated. As described above, in some embodiments, at least a portion of the components forming the refrigeration circuit may be thermally isolated from the ambient environment of the conditioned space (e.g., the bounded interior of the environment 300). In some embodiments, as shown in FIGS. 6A-6B, the thermal isolation may refer to components that may be thermally coupled components but for which the thermal burden for the space around the air plenum structure (e.g., the ambient environment) and/or heat exchange is reduced. Said differently, the thermal isolation between thermally coupled components may refer to the dissipation of heat associated with one or more of the thermally coupled components so as to reduce the thermal burden of the other of the thermally coupled component, such as by reducing the thermal burden inside the occupancy of a structure or building that is around the air plenum structure.

[0103] As shown, the air plenum structure 600 may refer to a housing, partial enclosure, and/or the like within which at least a portion of the compressor-condenser assembly 103 (e.g., the second group of system components) may be positioned. As such, the air plenum structure 600 may include a housing 601 that defines an interior space within which the condenser 110 and/or the compressor 114 may be positioned in an instance in which the air plenum structure 600 is coupled with the refrigeration system 100. The present disclosure contemplates that the dimensions (e.g., size and/or shape) of the housing 601 (e.g., or other structural elements, members, components etc. bounding the interior) may vary based on the associated size of the refrigeration system 100 and/or the compressor-condenser assembly 103. As shown in FIG. 6B, in operation in which the air plenum structure 600 is coupled with the refrigeration system 100, at least a portion of the condenser 110 and the compressor 114 (e.g., or a plurality of these components) may extend into the interior of the housing 601 forming the air plenum structure 600.

[0104] In some embodiments, as shown in FIG. 6B, the compressor-condenser assembly 103 is configured to be positioned at a top surface of the conditioned space (e.g., on top of the environment 300). Said differently, the compressor-condenser assembly 103 may be positioned on an exterior surface of a walk-in refrigeration system. In such an embodiment, the air plenum structure 600 may be configured to be attached to the top surface so as to substantially envelop the compressor-condenser assembly 103. In some embodiments, the air plenum structure 600 may be removably attached to the top surface, such as to, for example, allow for the installation of the components (e.g., compressor 114 and condenser 110) forming the compressor-condenser assembly 103. With continued reference to FIG. 6B, the attachment between the air plenum structure 600 and the top surface may be configured to substantially seal the compressor-condenser assembly 103 within the air plenum structure 600 (e.g., within the interior of the housing 601). In other words, the air plenum structure may, in conjunction with the top surface, form an environment in which the compressor-condenser assembly 103 may be positioned. In doing so, the heated rejection of these components, such as generated by performance of the refrigeration cycle, may be at least partially contained within the interior of the air plenum structure. For example, if the refrigeration system 100 operates as a walk-in system in an example kitchen (e.g., as shown in FIG. 3), the air plenum structure 600 may operate to prevent the heat generated by the compressor-condenser assembly 103 from permeating into the kitchen (e.g., the ambient environment) that may be adverse, detrimental, or otherwise unfavorable for such an environment.

[0105] In order to promote dissipation (e.g., via convective cooling of the like), of the heat generated by the compressor-condenser assembly 103 (e.g., the heated rejection) from the air plenum structure 600, the air plenum structure 600 may, as shown in FIGS. 6A-6B, define at least one plenum input 602 in fluid communication with an external environment of the air plenum structure 600 and at least one plenum output 604 in fluid communication with the external environment of the air plenum structure 600. In the example embodiment of FIGS. 6A-6B, the air plenum structure 600 includes a first air plenum input 602 and a second air plenum input 606 each of which are in fluid communication with the external environment of the air plenum structure 600. Although illustrated and described herein with reference to a first and second air plenum input 602, 606 and a plenum output 604, the present disclosure contemplates that the air plenum structure 600 may include any number of openings providing fluid communication with an external environment based on the intended application of the refrigeration system 100. Furthermore, as shown in FIG. 6B, the inputs 602, 606 and the plenum output 604 may be communicably coupled (e.g., in fluid communication with) the external environment via one or more conduits, channels, tubes, line sets, and/or the like through which a fluid/air may flow. In some embodiments, a temperature within the air plenum structure 600 may be greater than a temperature of the external environment.

[0106] In some embodiments, the air plenum structure 600 may further include an exhaust fan 608 coupled to the at least one plenum output 604. As would be evident to one of ordinary skill in the art in light of the present disclosure, the exhaust fan 608 may be configured to force heated air within the air plenum structure 600 to the external environment. Although described herein with reference to an example exhaust fan 608, the present disclosure contemplates that the air plenum structure 600 may leverage any technique or mechanism for moving heated air within the interior of the air plenum structure 600 to an external environment. The present disclosure similarly contemplates that the air plenum structure 600 may leverage any technique or mechanism for driving cooled (e.g., relatively lower temperature) air from the external environment (e.g., via the plenum inputs 602, 606) into the interior of the air plenum structure 600. In doing so, the air plenum structure of FIGS. 6A-6B may thermally isolate at least a portion of the components of the compressor-condenser assembly 103 so as to reduce the thermal burden of these components without impacting the location at which the refrigeration system 100 is installed (e.g., the occupancy or interior of a kitchen or the like).

[0107] With reference to FIG. 7, an example structural installation (e.g., operational configuration) of the refrigeration system 700 with thermal isolation is illustrated. As described above, in some embodiments, the thermal isolation of the present disclosure may be achieved by physically moving or otherwise distancing components such that the heat and associated temperature of one thermally isolated component has little to no impact on the heat and associated temperature of the other thermally isolated component. As shown in FIG. 7, for example, in an operational/installed configuration, the refrigeration system 700 may be installed in or otherwise positioned at a structure (e.g., a building or the like). In such an embodiment, at least a portion of the structure at which the refrigeration system 700 is installed may operate to thermally isolate at least a portion of the compressor-condenser assembly 103 (e.g., the condenser 110 or the like) from the conditioned space and the ambient environment of the conditioned space as described above.

[0108] For example, and as shown in FIG. 7, the portion of the structure operating to thermally isolate components may include an exterior wall 701 of the structure. Although described hereinafter with reference to an external wall, the present disclosure contemplates that any portion of the structure (e.g., floor, roof, ceiling, interior wall, etc.) may operate to thermally isolate one or more of the components described herein. As shown, the exterior wall 701 may define a first surface 703 proximate the conditioned space. The first surface 703 of the exterior wall 701 may refer to an interior surface (e.g., an interior of the structure). The exterior wall 701 may further define a second surface 705 opposite the first surface 703 that is proximate at least a portion of the compressor-condenser assembly 103 (e.g., the condenser 110). The second surface 705 of the exterior wall 701 may refer to an exterior surface (e.g., an exterior of the structure).

[0109] With continued reference to FIG. 7, at least a portion of the compressor-condenser assembly 103 (e.g., the condenser 110) is disposed in an external environment of the structure proximate the second surface 705. For example, during installation of the refrigeration system 700 at the structure, the condenser(s) 110 may be supported external to the structure in an external or ambient environment of the structure. The condenser 110 may be fluidically coupled (e.g. in fluid communication with the refrigeration circuit via one or more fluid line sets. In order to enable the connection between these components, the support structure may define one or more openings 702 configured to at least partially receive a fluid line set therein. To support the condenser(s) 110 exterior of the structure, one or more attachment mechanisms 707 (e.g., brackets or the like) may be used. During operation, heated rejection (e.g., heat generated by the condenser(s) 3) may be generated by performance of the refrigeration cycle described herein. By providing the condenser(s) 3 in an external environment of the structure, the heat may be dissipated to an external environment of the structure with minimal to no impact on the temperature on the interior of the structure.

[0110] FIG. 8 illustrates a transportation configuration of an example refrigeration system of FIG. 7, in accordance with an example of the present disclosure. For example, the condenser(s) 110 of the compressor-condenser assembly 103 may be placed on top of the refrigeration system 700 (e.g., the walk-in refrigerator) before installation (e.g., when leaving the factory or production location). The transportation configuration as shown in FIG. 8 may include quick disconnect fittings 505 as described above with reference to FIGS. 5A-5B and a fluid line set 704. The fluid line set 704 may be pre-connected a coiled for transport so that, at the structure, the condenser(s) 110 may be removed and relocated to an external environment exterior of the structure for installation as described herein.

[0111] It should be understood that while an exemplary system configuration is depicted with respect to the figures, these examples are non-limiting. It is envisioned that additional or alternative configurations may be included in the design of the refrigerant circuit, specifically depending on the specifications of the refrigeration system, walk-in refrigeration unit, and/or the like. While certain exemplary examples have been described and shown in the accompanying drawings, it is to be understood that such examples are merely illustrative of and not restrictive on the broad disclosure, and that this disclosure not be limited to the specific constructions and arrangements shown and described, since various other changes, combinations, omissions, modifications and substitutions, in addition to those set forth in the above paragraphs, are possible. Those skilled in the art will appreciate that various adaptations, modifications, and combinations of the just described examples can be configured without departing from the scope and spirit of the present disclosure. Therefore, it is to be understood that, within the scope of the appended claims, the present disclosure may be practiced other than as specifically described herein.

[0112] Also, it will be understood that, where possible, any of the advantages, features, functions, devices, and/or operational aspects of any of the examples of the present disclosure described and/or contemplated herein are combinable and/or included in any of the other examples of the present disclosure described and/or contemplated herein, and/or vice versa. In addition, where possible, any terms expressed in the singular form herein are meant to also include the plural form and/or vice versa, unless explicitly stated otherwise.