Patent Application
20180120017
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.
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.
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.
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
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
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.
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.
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 (
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 (
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.
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
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.
