US20180120017A1

US20180120017A1 - Refrigeration Device

Info

Publication number: US20180120017A1
Application number: US15/338,884
Authority: US
Inventors: Shawn Teto Wilson; Glenn Eric Bonney; Shawn Patrick Szilezy
Original assignee: Follett LLC
Current assignee: Follett Products LLC
Priority date: 2016-10-31
Filing date: 2016-10-31
Publication date: 2018-05-03

Abstract

A refrigeration device has a cabinet having a pair of refrigerated interior spaces and an upper compartment which houses removable compressor and evaporator modules. An air supply plenum is positioned between the refrigerated spaces to evenly provide cold air. The evaporator module has a removable, thermally insulative cover to facilitate servicing.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to refrigeration devices, such as refrigerators and freezers, and more particularly, to high performance refrigerators and freezers permitting close control of temperature.

2. Brief Description of Related Art

High performance refrigerators and freezers are employed in environments in which materials must be stored at controlled low temperatures, such as in scientific laboratories, pharmacies and hospitals. Such materials include samples of tissues, chemical reagents, vaccines, cell lines, plasma, blood, and other biological materials. Materials stored in refrigerators and freezers intended for domestic and commercial use frequently experience significant temperature fluctuations which are undesirable in scientific and medical contexts, as such fluctuations may result in the degradation of stored materials.
High performance refrigerators may include mechanisms for minimizing temporal and spacial temperature fluctuations. For example, U.S. Pat. No. 9,310,121, incorporated herein by reference, discloses a high performance refrigerator including a sacrificial evaporation which operates to avoid a temperature spike which would otherwise occur during a defrost cycle. Similarly, U.S. Publication 2013/0098075 A1, incorporated herein by reference, discloses a high performance refrigerator having an evaporator outside the refrigerated interior, and a eutectic member configured to melt at the operating temperature of the refrigerator. During a defrost cycle, the eutectic solidifies, withdrawing heat from the interior compartment.
Failure of a refrigeration device can result in significant inconvenience and/or a significant financial loss. Refrigeration devices include mechanical components required to transfer heat from within the controlled interior space to the exterior. Mechanical devices such as compressors and fans, may be designed for an extensive service life, but are subject to wear, and will ultimately fail. Frequently, the failed components can be replaced and the refrigeration circuit can be recharged with a refrigerant fluid. However, replacement can require significant time, during which the contents must be transferred to another refrigeration device or lost. In a domestic or commercial context, another refrigeration device is simply not available. In a medical, pharmacy or hospital context, such mechanical failures can result in the loss of critical, irreplaceable materials. Thus, there is a need for a refrigeration device which can be quickly and easily repaired in the event of a failure of a mechanical component, and which provides even temperature distribution and close control of temperature.
U.S. Pat. Nos. 5,953,929 and 6,070,424, each incorporated herein by reference, disclose a modular refrigeration unit intended for installation in a variety of different refrigerators and freezers, rather than installing each of the individual components of the refrigeration system separately in each such refrigerator or freezer. Similarly, U.S. Pat. No. 6,701,739, incorporated herein by reference, discloses a modular refrigeration system for a refrigeration appliance which is removable and replaceable in the event of the failure of a component of the system, such as the compressor or the condenser. U.S. Pat. No. 5,009,081, incorporated herein by reference, discloses a modular mechanical refrigeration unit which is relatively thin and is adapted to form one wall of a refrigeration appliance.
U.S. Pat. No. 6,209,342, incorporated herein by reference, discloses an evaporator housing for a refrigerator located between a refrigerator compartment and a freezer compartment. U.S. Patent Publication 2012/0152499, incorporated herein by reference, discloses an evaporator including a housing, a coil assembly, and a replaceable fan module. U.S. Pat. No. 5,878,592, incorporated herein by reference, discloses an evaporator housing for refrigerated transportation vehicles. U.S. Pat. No. 6,240,739, incorporated herein by reference, discloses an evaporator cover for a display refrigerator. U.S. Pat. No. 6,145,336, incorporated herein by reference, discloses a plastic mount for an evaporator for use in ice making machines. U.S. Pat. No. 6,134,909, incorporated herein by reference, discloses a housing for physically and thermally isolating the evaporator section of an air conditioning unit that is mounted on the cabin roof of a trailer or van. U.S. Pat. No. 4,086,785, incorporated herein by reference, discloses a two piece fan motor mount for a domestic refrigerator. U.S. Pat. No. 3,599,442, incorporated herein by reference, discloses a unitary fan evaporator assembly.

SUMMARY OF THE INVENTION

The present invention provides a refrigeration device comprising a cabinet having at least one refrigerated interior space and, in one presently preferred embodiment, a first refrigerated interior space and a second refrigerated interior space.
The cabinet also includes a compartment, which preferably houses at least one component of the refrigeration system used to remove heat from the first and second refrigerated interior spaces.
The refrigeration device also includes an air supply plenum to deliver refrigerated air to the at least one refrigerated interior space. In a presently preferred embodiment, the air supply plenum is positioned between the first and the second refrigerated spaces. This centrally disposed plenum advantageously delivers cooling air to all internal corners of the refrigerated interior spaces.
Preferably, the compartment includes a compressor module and an evaporator module, with a refrigerant fluid circulating between the compressor module and the evaporator module. Preferably, the compressor module is removable as a unit from the refrigeration device. It is also preferred that the compressor module be replaceable as a unit from the refrigeration device.
Further, it is preferred that the evaporator module is removable as a unit from the refrigeration device. It is also preferred that the evaporation module be replaceable as a unit from the refrigeration device.
The air supply plenum is adapted to provide air from the evaporator module to at least one refrigerated space.
In a presently preferred embodiment, the air supply plenum is adapted to provide air from the evaporator module to the first refrigerated interior space and the second refrigerated interior space.
The evaporator module preferably includes an evaporator and at least one fan for circulating air from the evaporator through the air supply plenum. Preferably, the evaporator module includes a removable cover, the removable cover permitting access to at least one component of the refrigeration system, such as an evaporator and/or an evaporator fan.
The refrigeration device also includes at least one return air plenum for collecting air from the first and the second refrigerated spaces for supply to the evaporator module.
In one presently preferred embodiment, the compartment is positioned above the first and second refrigerated interior spaces. In another embodiment, the compartment is positioned below the first and the second refrigerated spaces.
Preferably, the removable cover is formed from a thermally insulative material. Preferably, the thermally insulative material is an expanded polymeric material. Preferably, the expanded polymeric material is an expanded polypropylene. Preferably the thermally insulative material has thermal conductivity of less than 0.041 W/m-K at 24 degrees C. Preferably, the thermally insulating material is also elastic to provide a reusable seal without the need for any caulking, sealant, gaskets, or fasteners. Preferably, the thermally insulating material possesses flame-retardant properties. Preferably, the thermally insulating material includes anti-microbial agents. Preferably, the expanded polymeric material has a density of from about 46 to 81 g/L.
Preferably, either the compressor module or the evaporator module can be removed and replaced without having to discharge and recharge the refrigerant fluid which circulated between the compressor module and the evaporation module during operation of the refrigeration device.
Preferably, refrigerant is circulated between the compressor module and the evaporator module through self-sealing dry-break couplings. Preferably, each of the compressor module and the evaporator module include a portion of at least one self-sealing dry-break coupling which matingly engages with a corresponding portion of a corresponding self-sealing dry-break coupling on the other module.
Preferably, the evaporator module includes a shroud over the evaporator to prevent air returning from the first and second refrigerated spaces from bypassing the evaporator.
Preferably, the evaporator module includes return air supply ducts to provide balanced air from at least one return air plenum to the evaporator.
Preferably, the interior surfaces of the return air supply ducts and the removable cover are contoured to facilitate low air-side pressure drop through the evaporator.
Preferably, the evaporator module includes an upstanding partial enclosure for mating and sealing engagement with the removable cover.
Preferably, the compartment includes a mounting surface for the compressor module and the evaporator module, the upstanding partial enclosure of the evaporator module contacting the mounting surface and defining a contact area, the mounting surface being partially perforated in the vicinity of the contact area to enhance the thermal isolation of the evaporator module.
Preferably, the compartment is generally thermally insulated from the at least one interior refrigerated space, and the interior of the evaporator module is preferably generally thermally insulated from the interior of the compartment.
Preferably, the evaporator module includes at least one locking device for securing the cover over the evaporator. Preferably, the at least one locking device secures the cover to the upstanding partial enclosure. Preferably, cover is secured to the partial enclosure by a snap fit. Preferably, the cover is secured to the partial enclosure through a separable seam having an air seal. Preferably, the refrigeration device further includes at least one switch indicating when the cover is not securely fastened.
Preferably, the refrigeration device includes at least one alarm for sensing the temperature of the at least one interior refrigerated space, and providing a sensible indication, such as a visible or audible indication, when the temperature has risen above a predetermined upper limit temperature. Preferably, the refrigeration device includes at least one alarm for sensing the temperature of the at least one interior refrigerated device, and providing a sensible indication, such as a visible or audible indication, when the temperature has fallen below a predetermined lower limit temperature.
Preferably, the refrigeration device includes a recording device for monitoring at least one temperature inside the at least one interior refrigerated space and recording the at least one temperature.
Preferably, the refrigeration device includes a control unit for controlling at least one aspect of the operation of the refrigeration device.
In another aspect, the present invention provides a double door refrigeration device comprising a cabinet having a first and a second refrigerated interior space, preferably of generally equal volume, more preferably of equal volume. The cabinet includes a compartment for enclosing a refrigeration system including a compressor, a condenser, and an evaporator. An air supply plenum is positioned between the first and the second refrigerated spaces, and is adapted to provide air from the evaporator to the first and the second refrigerated spaces. At least one return air plenum is provided for collecting air from the first and the second refrigerated spaces and returning the air to the evaporator. Preferably, the compartment is positioned above the first and second refrigerated interior spaces. Preferably, the compartment has an interior, and the evaporator is positioned in a thermally insulative housing within the compartment. Preferably, the housing includes a removable cover. Preferably, the housing includes a shroud over the evaporator to prevent air returning from the first and second refrigerated spaces from bypassing the evaporator. Preferably, the housing includes return air supply ducts to provide balanced air from at least one return air plenum to the evaporator. Preferably, the interior surfaces of the return air supply ducts and the removable cover are contoured to facilitate low air-side pressure drop. Preferably, the housing includes an upstanding partial enclosure for mating and sealing engagement with the removable cover. Preferably, the compartment includes a mounting surface for the compressor and the housing, the upstanding partial enclosure of the housing contacting the mounting surface and defining a contact area, the mounting surface being partially perforated in the vicinity of the contact area to enhance the thermal isolation of the evaporator.
In yet another aspect, the present invention provides a self-contained evaporator module for use with a refrigeration device. The evaporator module includes an evaporator module housing and an evaporator. The evaporator module preferably includes at least one evaporator fan for drawing or pushing air through the evaporator to cool the air flowing through the evaporator. The evaporator module housing preferably includes an evaporator module base and an evaporator module cover. Preferably, the evaporator module base and evaporator module cover fit together tightly to provide a good seal against air flow between the interior of the evaporator module and the exterior. Preferably, the evaporator module cover is formed from a thermally insulating material. Preferably, the evaporator module base is formed from a thermally insulating material. Preferably, the thermally insulating material is also elastic to provide a reusable seal without the need for any caulking, sealant, gaskets, or fasteners. Preferably, the thermally insulating material possesses flame-retardant properties. Preferably, the thermally insulating material includes anti-microbial agents. Preferably, the interior of the evaporator module is divided into a warm air chamber and a cold air chamber. Preferably, the warm air chamber and the cold air chamber are separated by at least one interior wall formed in the housing and by the evaporator. More preferably, the warm air chamber and the cold air chamber are separated by the evaporator, and a pair of interior walls formed in the housing. Preferably, the pair of interior walls is symmetrically disposed on either side of the evaporator. Preferably, the pair of interior walls and the inner surface of the evaporator housing form a shroud enclosing the cold air chamber and separating the cold air chamber from the warm air chamber. Preferably, the interior walls seal the cold air chamber when the evaporator module base is securely covered with the evaporator module cover. Preferably, the warm air chamber extends along the width of a first end of the evaporator housing, and back to a second end of the evaporator housing symmetrically along either side of the evaporator housing, on the outside of the interior walls of the housing. Preferably, a pair of warm air supply apertures is formed in the evaporator housing base proximate the second end of the evaporator housing within the warm air chamber. Preferably, a cold air supply aperture is formed in the evaporator housing base generally centered within the cold air chamber. Preferably, the interior walls of the evaporator housing are formed from a pair of first upper and lower shroud walls and a pair of second upper and lower shroud walls, the first and second upper shroud wall being formed integrally with the evaporator housing cover, and the first and second lower shroud wall being formed integrally with the evaporator cover base.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of a refrigeration device according to the present invention, shown with the doors closed.

FIG. 2 is a perspective view of the refrigeration device of FIG. 1 as seen from the front lower right, with the doors removed to reveal the interior.

FIG. 3 is a perspective view of the refrigeration device of FIG. 1 as seen from the front upper right, with the upper compartment cover removed to reveal the interior of the upper compartment.

FIG. 4 is a top plan view of the refrigeration device of FIG. 1 shown with the upper compartment cover removed to reveal the interior of the upper compartment.

FIG. 5 is a top plan view of the refrigeration device of FIG. 1 shown with the upper compartment cover removed and the replaceable evaporator module removed to show the floor of the upper compartment under the evaporator module.

FIG. 6 is a perspective view of the compressor module of the refrigeration device of FIG. 1 shown removed from the refrigeration device.

FIG. 7 is a perspective view of the evaporator module of the refrigeration device of FIG. 1 shown removed from the refrigeration device with the cover rotated for removal to show the interior of the evaporator module and the interior detail of the cover.

FIG. 8 is another upper perspective view of the evaporator module shown in FIG. 7.

FIG. 9 is a perspective view of the evaporator module shown with the cover lifted off to reveal the interior of the module.

FIG. 10 is a partial perspective view of the refrigeration device of FIG. 1 shown from below with the central plenum removed and one of the warm air plenums partially removed.

FIG. 11 is a top plan view of the evaporator module shown in FIG. 7 shown with the evaporator cover and evaporator fan removed.

FIG. 12 is a perspective view of the refrigeration device of FIG. 1 as seen from the front lower right, with the doors, upper compartment walls, condenser module, and evaporator cover removed.

DETAILED DESCRIPTION

As used in the present specification and claims “refrigeration device” means a refrigerator or freezer.
The present invention provides a refrigeration device which can be quickly repaired in the event of a failure of a mechanical component.
The present invention also provides double-door refrigeration devices with central air flow distribution. Double-door refrigerators have a central partition or mullion that the doors close and seal upon. The present invention advantageously uses this natural partition to evenly supply cooling air to all internal corners of the refrigerated storage cabinet or interior spaces.
The present invention also evenly returns warm air through air ducts to the evaporator coil while maximizing air flow to the evaporator. The present invention provides an airflow design which maximizes evaporator coil heat exchange area with proper cross-sectional area for airflow while maintaining maximum refrigerated storage space.
In the present invention two separately replaceable modules are provided, a compressor module and an evaporator module. The two modules together provide all the components of the refrigeration system for the refrigeration device. The compressor module includes a compressor, a condenser, a condenser fan, and associated lines for transferring refrigerant fluid, as well as self-sealing dry-break couplings for connecting refrigerant lines to the evaporator module. The evaporator module includes an evaporator, an evaporator fan, and associated lines for transferring refrigerant, as well as self-sealing dry-couplings for connecting refrigerant lines to the compressor module. The compressor module and the evaporator module are housed in an upper compartment of the refrigeration device, and are mechanically attached to the floor of the upper compartment. The evaporator module is thermally isolated from the floor and the interior of the upper compartment. An easily removable thermally isolating cover is provided for the evaporator module to provide access to the evaporator and evaporator fan.
Referring now to the figures in which like reference numerals represent like elements in each of the several views, there is shown in FIG. 1 a front elevation view of a presently preferred embodiment of a refrigeration device 10 according to the present invention. The refrigeration device 10 includes a cabinet 20 having a thermally insulated right side wall 22 and a thermally insulated left side wall 24, as well as an openable, thermally insulated right door 26 and an openable, thermally insulated left door 28 providing access to the interior of the refrigeration device 10. The doors 26, 28 are provided with gaskets (not shown) to seal the interior of the refrigeration device 10 when the doors 26, 28 are closed, and are each provided with graspable upstanding handles 68 (best seen in FIG. 3) to permit an operator to open and close each door 26, 28. A pair of lockable, latches 40, 42 secure the doors 26, 28 in closed positions, to prevent unauthorized access to the contents of the refrigeration device 10. The mechanical components of the refrigeration system for removing heat from the interior of the refrigeration device 10 are housed in a compartment 30 positioned at the top of the refrigeration device 10. The compartment 30 includes a front wall 34 to which is mounted a downwardly directed control display 36 for providing information about the status of the refrigeration device, such as the operating temperature. In addition, several panels 38 are provided for receiving and mounting optional accessories, such as a chart recorder that can display the temperature history of the interior of the refrigeration device 10. A cover 80 and a right side wall 82 and a left side wall 84 are provided for enclosing the compartment 30.
FIG. 2 is perspective view of the refrigeration device 10 of FIG. 1, shown from the lower right, with the doors 26, 28 removed to show the interior of the refrigeration device 10. The refrigeration device includes a bottom wall or floor 46 as well as a rear wall 48. The side walls 22, 24, bottom wall 46 and rear wall 48, and doors 26, 28 (FIG. 1) enclose a first or right interior refrigerated space 50 and second or left interior refrigerated space 52 of five sides when the doors 26, 28 are closed. An upper wall 62 encloses the interior spaces 50, 52 above. Each of the walls 22, 24, 46 and 62 and the doors 26, 28 are preferably thermally insulated, such as, for example, by filing with polyurethane foam, extruded polystyrene panels, vacuum panels, or the like.
Cold air is provided to the interior refrigerated spaces 50, 52 through a central refrigerated air supply plenum 54 which is provided with a plurality of refrigerated air supply vents 56 for fluid communication with both the right interior refrigerated space 50 and the left interior refrigerated space 52.
Warm air is returned from the right interior refrigerated space 50 and left interior refrigerated space 52 through a pair of warm air return plenums 58 mounted at the upper ends of the refrigerated interior spaces 50, 52 and below the upper wall 62 (best seen in FIG. 10). Each of the warm air return plenums 58 is provided with warm air return vents 60.
In this presently preferred embodiment, the right interior refrigerated space 50 and the left interior refrigerated space 52 are of equal dimensions and volume, and cold air is supplied to each in equal amount. However, it is understood that while two interior spaces 50, 52 are shown, the interior of the refrigeration device 10 could include only a single refrigerated interior space, or more than a pair of refrigerated interior spaces, with the refrigerated air supply plenum 54 being modified to provide refrigerated air to each such space. Further, while refrigerated air is being supplied in equal quantities to either refrigerated interior space in the illustrated presently preferred embodiment, the quantity of refrigerated air supplied to either refrigerated interior space can differ, such as, when it is desired to operate one refrigerated space as a freezer and the other refrigerated space as a refrigerator.
FIG. 3 is a perspective view of the refrigeration device 10 as seen from the front upper right, with cover 80 of the upper compartment 30 being removed to show the interior of the compartment 30. The compartment includes a lower wall or floor 72 on which is mounted a compressor module 100 including a compressor 102 and condenser 104 and a centrally disposed evaporator module 120 including a thermally insulating evaporator cover 130 which seals the interior 148 of the evaporator module or compartment (FIGS. 7 and 8) from the remainder of the interior space of the upper compartment 30. The compressor module 100 and the evaporator module 120 are in fluid communication through pairs of dry- break couplings 108, 128.
FIG. 4 is a top plan view of the refrigeration device 10 of FIG. 1 shown with the upper compartment cover removed 80 (FIG. 1) to reveal the interior of the upper compartment. The compressor module 100 and the generally centrally located evaporator module 120 are mechanically secured to the floor 72 of the upper compartment 30 and in fluid communication with one another through a plurality of refrigerant lines 110, 112, 114, 116. The refrigerant lines 110, 112, 114, 116, include a first refrigerant supply line 110 extending from the condenser 104 mounted on the compressor module 100 and connected to a second refrigerant supply line 112 mounted on the evaporator module 120, as well as a first refrigerant return line 114 mounted on the evaporator module 120 and connected to a second refrigerant return line 116 mounted on the compressor module 100. The first and second refrigerant supply lines 110, 112 and the first and second refrigerant return lines 114, 116 are secured to one another by dry- break couplings 108, 128.
An evaporation pan 118 is provided in the floor of the compressor module 100 to receive condensate discharged from the evaporator module 120 when the evaporator 122 is defrosted. The outlet of the compressor 102 is in fluid communication with the inlet of the condenser 104 through a condensate heating line 140 running through the evaporation pan 118. Hot refrigerant output from the compressor 102 provides heat to any liquid condensate in the evaporation pan 118 to speed evaporation of the liquid condensate back into the atmosphere. The condensate is provided from the evaporator module 120 by a drain line 142 extending above the evaporation pan 118.
FIG. 5 is a top plan view of the refrigeration device 10 of FIG. 1 shown with the cover 80 of the upper compartment 30 removed and the replaceable evaporator module 120 removed to show the floor 72 of the upper compartment 30 under the evaporator module 120. The floor 72 includes a pair of warm air return apertures 74 positioned under the evaporator module 120 so that the warm air return plenum 58 is in fluid communication with warm air intakes of the evaporator module 120. In addition, the floor 72 includes a centrally disposed cold air supply aperture 76 positioned under the evaporator module 120 such that the refrigerated air supply plenum 54 is in fluid communication with the cold air supply outlet of the evaporator module 120. Further, the floor 72 of the upper compartment 30, which is preferably formed from a high strength, light weight material, such as a sheet metal, such as steel or aluminum, includes a series of elongated apertures or perforations 78 arranged in a generally rectangular shape and positioned immediately below the walls of the evaporator module 120, such that contact between the floor 72 and the evaporator module 120 is substantially reduced. The volume between the floor 72 of the upper compartment 30 and the upper wall 62 of the interior spaces is preferably filled with a thermally insulative material, and the series of perforations or elongated apertures 78 in the floor 72 increase the thermal isolation of the evaporator module 120 within the refrigeration device 10.
FIG. 6 is a perspective view of the compressor module 100 of the refrigeration device 10 of FIG. 1 shown removed from the refrigeration device 10. The compressor 102 is mounted on the base 150 of the compressor module 100 vibration-damping feet 152.
FIG. 7 is a perspective view of the evaporator module 120 of the refrigeration device 10 of FIG. 1 shown removed from the refrigeration device 10 with the evaporator cover 130 rotated for removal to show the interior of the evaporator module 120 and the interior detail of the cover 130 of evaporator module 120. The evaporator module 120 includes the components of the low temperature portion of the refrigerator: the evaporator heat exchanger (a.k.a. “coil”) 125, such as plate-fin and tube style, and the air circulating fan or fans 124. The evaporator module 120 includes a generally centrally disposed evaporator 122, supplied with refrigerant fluid from the compressor module 100 through the second refrigerant supply line 112 via a dry-break coupling 128 and a capillary or thermal expansion valve 126. Refrigerant fluid returns from the evaporator module 120 to the compressor module 100 through the first refrigerant return line 114 via another dry-break coupling 128. The evaporator 122 is mounted on an evaporator module base 144. An upstanding wall 146 extends generally vertically from the edges of the base 144 to partially enclose the interior 148 of the evaporator module 120. The cover 130 of the evaporator module 120 is shown rotated up and off the upstanding wall 146 along the dashed line 180 to reveal the interior of the evaporator module 120. The evaporator module base 144, the upstanding wall 146, and the evaporator cover 130 together comprise an evaporator housing 121. The upper edge 182 of the upstanding wall 146 and the lower edge 184 of the cover 130 are adapted to fit tightly together in mating and sealing engagement when the cover 130 is affixed to the upstanding wall 146. A snap fit engagement is preferably provided. The interior 148 of the evaporator module 120 is divided into a warm air chamber 160 and a cold air chamber 170 by the evaporator 122 and a shroud 132. Air is drawn from the warm air chamber 160 through the evaporator 122 by an evaporator fan 124 and expelled to the cold air chamber 170.
The shroud 132 is formed by a first upstanding lower shroud wall 162 and a second upstanding lower shroud wall 164, each extending upward from the base 144 of the evaporator module 120, and a first upper shroud wall 166 and a second upper shroud wall 168, each of which extend generally downward from the underside of the evaporator cover 130. Each of the lower shroud walls 162, 164 matingly engage with a respective upper shroud wall 166, 168 to form an air-tight seal when the evaporator cover 130 is mounted on the upstanding wall to seal the warm air chamber 160 from the cold air chamber 170.
Centered proximate a first edge of the base 144 of the evaporator module 120 is a refrigerated air supply aperture 145 (FIG. 11) which is in register with the cold air supply aperture 76 formed in the floor 72 of the upper compartment 30 to permit refrigerated air from the evaporator module 120 to flow through the refrigerated air supply plenum 54 to the first refrigerated interior space 50 and the second refrigerated interior space 52
Flanking the refrigerated air supply aperture and formed proximate second and third edges of the base 144 of the evaporator module 120 are first and second warm air return apertures 147 (FIG. 11), each of which is in register with a respective warm air return aperture 74 formed in the floor of the upper compartment 72 when the evaporator module 120 is mounted in the refrigeration device 10. The first and second warm air return apertures permit warm air from the first refrigerated interior space 50 and the second refrigerated interior space 52 to flow through the warm air return plenum 58 to the warm air chamber 160.
The upstanding wall, evaporator cover 130, and shroud 132 provide two integrated evaporator air supply ducts 200, 210 that distribute balanced air from return plenum 58 and direct balanced air flow to evaporator 122 and evaporator fan 124
The surfaces of the base of the evaporator module 120, the shroud 132 and the interior of the evaporator cover 130, are formed and contoured to minimize the air-side pressure drop through the evaporator 122 in order to minimize energy consumption and maximize heat transfer from the evaporator fan 124.
Preferably, the air-side pressure drop through the evaporator is no more than 0.2 inches H₂O, and more preferably no more than 0.1 inches H₂O. Preferably, the overall pressure drop for the air flow side from the cold air supply inlet, through the cabinet of the refrigeration device, through the return air ducting, and up to the face of the evaporator inlet face, is no more than 0.35 inches H₂O, and more preferably, no more than 0.25 inches H₂O.
A defrost heater 190 is provided proximate the evaporator 122 to heat the evaporator coils during defrost cycles in order to melt frost forming on the evaporator coils which otherwise would degrade the performance of the refrigeration device 10. Melt water from the defrost heater collects in a recess or drain pan formed in the base 144 of the evaporator module 120 and drains out through the drain line 142 to the evaporation pan 118 formed in the condenser module 120.
Preferably, each of the components of the evaporator housing 121, including in particular the removable evaporator cover 130, is formed from a thermally insulative material. Preferably, the thermally insulative material is an expanded polymeric material. Preferably, the expanded polymeric material is an expanded polypropylene. Preferably the thermally insulative material has thermal conductivity of less than 0.041 W/m-K at 24 degrees C. Preferably, the expanded polymeric material has a density of from about 46 to 81 g/L. The polymeric material can optionally include additives to provide fire retardancy and/or antimicrobial properties. Preferably, the thermally insulating material is sufficiently elastic to provide a reusable seal without the need for any caulking, sealant, gaskets, or fasteners.
FIG. 8 is another upper perspective view of the evaporator module 120 shown in FIG. 7.
FIG. 9 shows a safety feature that ensures the evaporator housing cover 130 is securely installed after service is complete. One to four mechanical switches 136 are provided, one placed at each side of the evaporator housing. Optionally, these switches connect to a LED light indicator (not shown). When the evaporator cover 130 is properly placed the LED indicator go off. If the cover is not securely installed the LED remains on indicating the cover is not fully secure.
Alternatively, electric circuitry is provided (not shown) to connect the switches 130 to the electronic control (not shown) of the refrigeration device 10 such that the refrigeration device 10 will not operate unless the switches 136 are closed, thus ensuring that the cover 130 sealingly engages the upstanding wall 146 to thermally isolate the interior 148 of the evaporator module 120 before the refrigeration device 10 can be operated.
Sensible indications (not shown), such as lamps, or audible devices, can be provided to signal that the cover 130 has been securely affixed to the upstanding wall 146.
Secure installation of the evaporator cover 130 is important to the performance of the refrigeration device 10, therefore having a means to ensure the evaporator cover is 130 properly installed is of significant value.
The refrigeration device 10 of the present invention can be quickly serviced. For example, a qualified service technician can access the upper compartment 30 with the help of a step ladder and separate the self-sealing dry break coupling to remove and replace a compressor module 100 having a failed component in a short period of time, such as 30 minutes. Meanwhile, the interior spaces of the refrigeration device 10 and the evaporator module 120 remain thermally isolated, protecting the contents of the refrigeration device against thermal degradation.
Similarly, in the event that there is an evaporator fan 124 failure, or thermal expansion valve 126 failure, or an evaporator coil failure the technician would lift off the evaporator housing cover 130 to gain access to the failed components. To replace the evaporator module 120 the technician would access the self-sealing dry-break couplings. The evaporator unit can be quickly replaced with a fully-functional evaporator module 130. The double-door refrigeration device 10 could be operational within 30 minutes.
Preferably, the refrigeration device 10 includes at least one temperature sensing device (not shown) for each of the refrigerated chambers 50, 52 for sensing the temperature of the interior of the refrigeration device 10. Preferably, the refrigeration device 10 is provided with means for displaying to an observer and/or recording the temperature sensed by each such sensing device (or some weighted average or other function thereof). Preferably, the refrigeration device 10 is provided with at least one alarm providing a sensible indication, such as a visible or audible indication, when there is a change in the operating status of the refrigeration device 10, such as when the temperature has risen above a predetermined upper limit or below lower temperature, and/or there has been a failure of one of the mechanical components such as the compressor 102, the condenser fan 106, the evaporator fan 124, and/or there has been a power failure. In addition, or alternatively, the refrigeration device 10 can be provided with an Internet connection so that the status of refrigeration device 10 (including the sensed temperature(s) of the interior, the set limit temperatures for the alarms, etc.) can be remotely monitored and/or controlled.
The refrigeration device 10 also preferably includes electronic control (not shown) for controlling operation of the mechanical components of the refrigeration system.
Air circulation within the refrigeration device 10 is illustrated in FIGS. 11 and 12. Warm air (schematically depicted by the arrows 220) is drawn from the first and second refrigerated interior spaces 50, 52 through the warm air return plenums (FIG. 12) and up through warm air supply apertures 147 in the base 144 of the evaporator module 120 into the warm air chambers 160 (FIG. 11). The warm air 220 is then drawn through the evaporator 122 where it is cooled, to provide cold air (schematically depicted by the arrows 230). The cold air 230 is pushed out of the evaporator module 120 by the evaporator fan 124 and into the refrigerated air supply plenum 54 and out through the refrigerated air supply vents 56 into the first and second interior spaces 50, 52.
Various modifications can be made in the details of the various embodiments of the refrigeration device of the present invention, all within the scope and spirit of the invention and defined by the appended claims.

Claims

1. A refrigeration device comprising:

a) a cabinet having a first and a second refrigerated interior space;

b) the cabinet including a compartment;

c) an air supply plenum positioned between the first and the second refrigerated spaces;

d) the compartment including a compressor module and an evaporator module, with a refrigerant fluid circulating between the compressor module and the evaporator module;

e) the air supply plenum being adapted to provide air from the evaporator module to the first and the second refrigerated spaces;

f) the evaporator module including an evaporator and at least one fan for circulating air from the evaporator through the plenum;

g) the evaporator module being removable from the refrigeration device;

h) the evaporator module including a removable cover;

i) the compressor module being removable from the refrigeration device;

j) at least one return air plenum for collecting air from the first and the second refrigerated spaces.

2. A refrigeration device according to claim 1 wherein the compartment is positioned above the first and second refrigerated interior spaces.

3. A refrigeration device according to claim 1 wherein the compartment is positioned below the first and the second refrigerated spaces.

4. A refrigeration device according to claim 1 wherein the removable cover is formed from a thermally insulative material.

5. A refrigeration device according to claim 1 wherein the refrigerant is circulated between the compressor module and the evaporator module through self-sealing dry-break couplings.

6. A refrigeration device according to claim 1 wherein the evaporator module includes a shroud over the evaporator to prevent air returning from the first and second refrigerated spaces from bypassing the evaporator.

7. A refrigeration device according to claim 1 wherein the evaporator module includes return air supply ducts to provide balanced air from at least one return air plenum to the evaporator.

8. A refrigeration device according to claim 7 wherein the interior surfaces of the return air supply ducts and the removable cover are contoured to facilitate low air-side pressure drop.

9. A refrigeration device according to claim 1, wherein the evaporator module includes an upstanding partial enclosure for mating and sealing engagement with the removable cover.

10. A refrigeration device according to claim 9, wherein the compartment includes a mounting surface for the compressor module and the evaporator module, the upstanding partial enclosure of the evaporator module contacting the mounting surface and defining a contact area, the mounting surface being partially perforated in the vicinity of the contact area to enhance the thermal isolation of the evaporator module.

11. A refrigeration device according to claim 1, further including at least one switch indicating when the cover is not securely fastened.

12. A double door refrigeration device comprising:

a) a cabinet having a first and a second refrigerated interior space;

b) the cabinet including a compartment for enclosing a refrigeration system including a compressor, a condenser, and an evaporator;

e) the air supply plenum being adapted to provide air from the evaporator to the first and the second refrigerated spaces;

f) at least one return air plenum for collecting air from the first and the second refrigerated spaces and returning the air to the evaporator.

13. A refrigeration device according to claim 12 wherein the compartment is positioned above the first and second refrigerated interior spaces.

14. A refrigeration device according to claim 11 wherein the compartment has an interior, the evaporator being positioned in a thermally insulative housing within the compartment.

15. A refrigeration device according to claim 14 wherein the housing includes a removable cover.

16. A refrigeration device according to claim 15 wherein the housing includes a shroud over the evaporator to prevent air returning from the first and second refrigerated spaces from bypassing the evaporator.

17. A refrigeration device according to claim 14 wherein the housing includes return air supply ducts to provide balanced air from at least one return air plenum to the evaporator.

18. A refrigeration device according to claim 17 wherein the interior surfaces of the return air supply ducts and the removable cover are contoured to facilitate low air-side pressure drop.

19. A refrigeration device according to claim 14, wherein the housing includes an upstanding partial enclosure for mating and sealing engagement with the removable cover.

20. A refrigeration device according to claim 19, wherein the compartment includes a mounting surface for the compressor and the housing, the upstanding partial enclosure of the housing contacting the mounting surface and defining a contact area, the mounting surface being partially perforated in the vicinity of the contact area to enhance the thermal isolation of the evaporator.

21. A self-contained evaporator module for use with a refrigeration device, the evaporator module including:

a) an evaporator module housing having an interior and an evaporator;

b) at least one evaporator fan for drawing or pushing air through the evaporator to cool the air flowing through the evaporator;

wherein the evaporator module housing preferably includes:

an evaporator module base and an evaporator module cover, the evaporator module base and evaporator module cover fitting together tightly to provide a seal against air flow between the interior of the evaporator module and the exterior, the evaporator module cover being formed from a thermally insulating material, the interior of the evaporator module being divided into a warm air chamber and a cold air chamber, the warm air chamber and the cold air chamber being separated by at least one interior wall formed in the housing and by the evaporator.