The present disclosure pertains generally to a refrigerated merchandiser, as well as to a refrigerated cabinet kit comprising one or more field-installable refrigeration system modules configured to be releasably and operably mounted and installed on a cabinet module to form a refrigerated merchandiser.
Reach-in refrigerated cabinets have access doors and are used to store and/or display refrigerated goods. One well-known type of refrigerated reach-in cabinet is a display refrigerated merchandiser. Conventionally, there are two types of refrigerated merchandisers: (1) the self-contained type and (2) the remote refrigeration type. The United States Department of Energy's regulations differentiate between self-contained and remote refrigeration systems. For example, energy consumption regulations for self-contained refrigeration systems are based on the measured energy consumption of the machinery, whereas energy consumption regulations for remote refrigeration systems are based on refrigerant mass flow and calculated assumptions of electrical loads.
Self-contained merchandisers are prefabricated assemblies comprising a cabinet with an integrated refrigeration system. In many self-contained merchandisers, the refrigeration systems are hermetically sealed so that there is no loss of refrigerant through access valves or mechanical connections. The refrigeration system in a self-contained merchandiser is precisely engineered for the application and applicable regulations, accounting for the size of the cabinet, the loads, and the temperature requirements. Compliance with these constraints enables self-contained merchandisers to operate very efficiently in comparison with remote refrigeration merchandisers (discussed below). Self-contained merchandisers can employ onboard systems for removing condensate that forms on the refrigeration system without separate drain connections. Air-cooled self-contained merchandisers only require a single cord and plug electrical connection to operate. Water-cooled self-contained merchandisers require only a single cord and plug electrical connection and a water connection for removing heat from the condenser. This makes self-contained merchandisers a preferred option for retailers that lease their buildings or otherwise require the refrigeration cabinet to occasionally be moved from place to place within the building.
Remote refrigeration merchandisers, by contrast, are commonly built into a retail building at the time of deployment. Most typically, a refrigeration system for a plurality of remote merchandiser cabinets is installed on the roof of a building and the merchandiser cabinets are installed as fixtures inside the building such that they are physically separated from the remote refrigeration system components by the building's roof. HVAC contractors must make refrigeration connections between evaporators mounted inside the cabinet and the piping chases that connect the merchandiser to the remote condenser, which is typically located on the building roof (Not all remote refrigeration systems are on the rooftop. There are mechanical rooms that house these at times.) In addition, to address the condensate that forms on the evaporator during use, a plumber must make a drain connection between a condensate removal line of the cabinet and the building's drain line, which usually runs in a trench under the floor of the cabinet. Occasionally, hoses and pumps can be used to send the condensate to a heated drain pan. Lastly, electrical connections are provided by an electrician as remote refrigeration is a fixed installation. Thus, remote refrigeration merchandisers are most suitable for retailers that own or have very long-term leases on retail buildings due to the trenching in the flooring to run refrigerant lines, drain water, and electrical cables. In addition to the inherent permanence of a remote refrigeration merchandiser, another disadvantage of remote refrigeration systems in relation to self-contained merchandisers is operating efficiency. To ensure that the necessary refrigeration capacity is always available, refrigeration systems mounted on the roof or remote locations of the building are typically oversized in relation to the actual refrigeration requirements of the cabinets deployed inside the building. In other words, remote refrigeration systems lack the application-specific engineering of their self-contained counterparts. This is due to the approach to sizing the refrigeration systems. Remote systems must consider seasonal fluctuations of outdoor temperatures and running multiple different products (freezers, refrigerators, floral, etc.) cabinets off of the same refrigeration system sized for worst case conditions. In this way, each cabinet consumes what it needs from a hypothetical endless cooling source. Furthermore, because the refrigeration, plumbing, and electrical connections must all be made in the field, remote refrigeration merchandisers are never hermetically sealed and are much more prone to water and refrigerant leaks. Refrigerant leaks are extremely detrimental to the environment and generate reoccurring installation costs.
The advantage that remote refrigeration merchandisers have had over self-contained merchandisers is greater “pack out,” which refers to the usable available space inside the merchandiser for holding saleable merchandise. A typical self-contained merchandiser in the same footprint will have less pack out as it contains the condenser and compressor portions of the refrigeration circuit.
Because remote refrigeration cabinets are often deployed when the building is being constructed (or remodeled for a particular purpose), the cabinets are often installed into the building by a crane before a roof is put in place. By contrast, self-contained merchandiser cabinets, because of how they are intended to be used, must be able to fit through a doorway of a standard-height man door (e.g., a doorway of no more than eight feet in height e.g., a doorway of no more than seven feet or a doorway having a height of about 82 inches). Furthermore, in a remote refrigeration merchandiser, the space taken up by refrigeration components inside the building is minimal, since many of the major mechanical components of the refrigeration system are located remotely. By contrast, existing self-contained merchandisers must physically contain and support all the refrigeration system components within the envelope of the unit, which again must be able to fit through a standard-height door.
To increase the pack out of merchandisers that are still at least somewhat portable and able to be deployed through a standard-height doorway, a third type of merchandiser has recently become available that combines aspects of self-contained and remote refrigeration merchandisers. This third type of merchandiser does not yet have an industry standard name or definition. But in essence, the type consists of two separate modules that can be assembled together as a kit in the field. The first module is a cabinet module that is sized to fit through a standard-height doorway, and the second module is a refrigeration system module that likewise fits through a standard-height doorway. Further, the refrigeration system module is configured to be installed on the cabinet module after both modules are in the building. Thus, the third type of merchandiser comprises a field-installable refrigeration system that is configured to be supported on a cabinet. Examples of field-installable, self-supporting merchandisers are the hybrid display cases sold by Zero Zone and the Freedom merchandisers sold by Hussmann. In these systems, the cabinet module includes an evaporator unit and the condensing unit is initially provided as a separate module from the cabinet module. A mechanical field-installed refrigeration connection is made by a certified refrigeration technician between the condensing unit and the evaporator in the cabinet module in the field.
In large volume merchandisers, pressure differentials between the inside and the outside of the cabinet can create difficulties for a user. Whenever the user opens the door to a merchandiser, warm air rushes into the cabinet. When the door closes, the temperature of the warm air rapidly decreases, yielding a corresponding decrease in pressure. In a well-sealed cabinet, this creates a pressure difference between the inside and outside of the cabinet. In a large volume merchandiser, this creates a vacuum effect on the doors that makes the doors very difficult to open. Various ways of addressing this problem have been proposed in the past. For example, some have proposed to incorporate a door handle mechanism that breaks the door seal when a user tries to open the door. More commonly it has been suggested to incorporate a pressure relief valve system into the refrigerated cabinet that acts passively to automatically equalize the pressures inside and outside the merchandiser by opening in response to any substantial pressure differential between the inside and outside of the cabinet.
In one aspect, a field-installable refrigerated merchandiser kit comprises a cabinet module having an exterior and an interior. A prefabricated refrigeration system module is configured to operatively connect to the cabinet module for cooling the interior. The prefabricated refrigeration system module is separate from the cabinet module. The prefabricated refrigeration system module and the cabinet module comprise mutual connection fittings configured to releasably and operatively connect the prefabricated refrigeration system module to the cabinet module for cooling the interior of the cabinet module. The prefabricated refrigeration system module includes a pressure relief valve configured to automatically open in response to pressure of the interior of the cabinet module being less than pressure of the exterior of the cabinet module whereby the pressure relief valve is configured to equalize pressure between the interior and the exterior of the cabinet module.
In another aspect, a method of equipping a refrigerated storage device cabinet with sufficient pressure equalization capacity to equalize pressure between an interior and an exterior the refrigerated storage device cabinet comprises providing a plurality of pairs of supply air inlets and return air outlets in the refrigerated storage device cabinet. A plurality of refrigeration systems configured to operatively connect to the refrigerated storage device cabinet for cooling the interior is provided. Each prefabricated refrigeration system comprises a pressure relief valve configured to automatically open in response to pressure a pressure differential across the pressure relief valve. Each of the plurality of refrigeration systems is installed on the refrigerated storage device cabinet such that each refrigeration system is configured to cool the refrigerated storage device cabinet by imparting cold air into the cabinet and withdrawing return air from the cabinet and such that each pressure relief valve is configured to open in response to pressure of the interior of the refrigerated storage device cabinet being less than pressure of the exterior of the refrigerated storage device cabinet whereby the pressure relief valves of the plurality of refrigeration systems equalize the pressure of the interior of the refrigerated storage device cabinet with the pressure of the exterior of the refrigerated storage device cabinet.
In another aspect, a refrigerated storage or display device comprises a cabinet having an interior and an exterior. An evaporator enclosure comprises an insulated wall separating an interior of the evaporator enclosure from the exterior. The insulated wall defines a pressure relief valve opening. A refrigeration system for cooling the interior of the cabinet includes an evaporator assembly in the evaporator enclosure. A frosting chamber in the evaporator enclosure between the insulated wall and the evaporator assembly has a chilled interior frosting surface. The frosting chamber is immediately adjacent to the evaporator assembly such that the frosting chamber is cooled by the evaporator assembly. An evaporator drain pan is below the evaporator assembly and the frosting chamber. A pressure relief valve in the pressure relief valve opening comprises a valve heater configured to heat the pressure relief valve to prevent frost from forming inside the pressure relief valve. The pressure relief valve is configured to open in response to pressure of the interior of the cabinet being less than pressure of the exterior of the cabinet whereby outside air containing moisture is introduced into the refrigeration system and then into the interior of the cabinet through the pressure relief valve until the pressure of the interior of the cabinet equalizes with the pressure of the exterior of the cabinet. The pressure relief valve is configured to direct the outside air into the interior of the cabinet through the frosting chamber such that moisture in the outside air introduced through the pressure relief freezes as frost on the chilled interior frosting surface of the frosting chamber. A defrost heater configured to periodically conduct defrost cycles during which the defrost heater defrosts the evaporator. The frosting chamber is located in relation to the defrost heater such that frost formed on the chilled interior frosting surface defrosts and drains into the evaporator drain pan during the defrost cycles.
In another aspect, a refrigerated storage or display device comprises a cabinet having an interior and an exterior. A refrigeration system for cooling the interior of the cabinet includes an evaporator and an evaporator fan configured to move cabinet air across the evaporator in a flow direction. A pressure relief valve is configured to open in response to pressure of the interior of the cabinet being less than pressure of the exterior of the cabinet whereby outside air containing moisture is introduced into the refrigeration system and then into the interior of the cabinet through the pressure relief valve until the pressure of the interior of the cabinet equalizes with the pressure of the exterior of the cabinet. A baffle between the pressure relief valve and the evaporator is being chilled by the evaporator. The baffle configured to redirect air entering the refrigerated storage or display device so that the air entering the refrigerated storage or display device flows along the baffle in a different direction than the flow direction before flowing across the evaporator in the flow direction.
Other aspects and features will be apparent hereinafter.
Corresponding reference characters indicate corresponding parts throughout the drawings.
The inventors have recognized several drawbacks to existing refrigerated merchandisers with field-installable, on-cabinet refrigeration systems. In particular, every existing product of this type requires a portion of the refrigeration system to be received into the interior of the cabinet. This reduces pack-out volume and also creates challenges with servicing and repairing the refrigeration system. In particular, a service technician often must access at least portions of the refrigeration system from inside the refrigerated interior to complete a repair. This requires the retailer to unpack the merchandiser before servicing, which creates a substantial disruption in retail operations. In addition, all existing field-installable, on-cabinet merchandisers require plumbing connections to be made in the field to address the condensate byproduct of refrigeration. Most typically, a technician must install a water pump and piping along the back of the cabinet for pumping condensate from a condensate pan located under the cabinet to an evaporation tray on top of the cabinet. The field-installed plumbing provides an opportunity for leaks and also requires the cabinet to be mounted away from the wall to leave space for piping and plumbing. Usable height is also reduced by the condensate pan and pump which conventionally reside below the cabinet.
Referring to
Providing the refrigerated merchandiser as a field-installable kit instead of as a prefabricated, all-in-one, self-contained refrigeration cabinet allows for a larger cabinet and greater pack-out volume than traditional self-contained merchandisers but still allows the merchandiser to be delivered through a standard-height man door. Thus, in one or more embodiments, each cabinet module 11 and each prefabricated refrigeration system module 12 is configured to fit upright through a doorway of a standard-height man door having a height of less than or equal to eight feet (e.g., a doorway of no more than seven feet or a height of about 82 inches). To maximize pack-out depth, it may be desirable in certain circumstances to design the cabinet module 11 so that it is too large to fit through a single-door doorway of 36 inches or less. In other words, a double-door man doorway may be required to deliver certain embodiments of the cabinet module 11 into a building. However, it is expressly contemplated that cabinet modules in the scope of this disclosure may be constructed and arranged to fit through a single-door man doorway having a height of less than or equal to seven feet and a width of less than or equal to 36 inches.
Referring to
In the illustrated embodiment, the kit 10 is configured to provide a refrigerated merchandiser 10′. However, it is also contemplated that kits for forming other types of refrigerated cabinets may be used without departing from the scope of the disclosure. For example, aspects of the present disclosure are particularly well-suited to any refrigerated cabinets of the upright, refrigerated type, including merchandisers with either doors or air curtains and merchandisers employing either air-cooled or water-cooled refrigeration systems.
Referring to
Referring to
The illustrated cabinet module 11 is configured to form a reach-in cabinet. Those skilled in the art will recognize that reach-in cabinets hold goods inside so that a user can access all of the goods from a station in front of the cabinet. In the typical reach-in cabinet, a normal-sized, able-bodied user can reach goods stored even at the back end of the free refrigerated space.
It can be seen in
What follows is a description of one particular embodiment of a field-installable refrigerated merchandiser kit 10 and corresponding merchandiser 10′ depicted in
The cabinet module 11 may comprise various internal product supports without departing from the scope of the disclosure. In the illustrated embodiment, vertically spaced shelves 24 are supported on the cabinet module 11 for holding merchandise for sale. However, other product support/display configurations are also possible. For example, in certain embodiments, merchandise for sale or other refrigerated goods may be supported in the free refrigerated space on a roll-in cart (not shown). As will be explained more fully below, this is possible because the illustrated cabinet module 11 is configured to support the entire refrigeration system on the top wall 18 of the cabinet. No portion of the refrigeration system is located at the lower end of the free refrigerated space. Thus, in one or more embodiments, the bottom walls 20 of the cabinet module is removed or lowered to be nearly flush with the ground so that the free refrigerated space can extend downward substantially to ground level. This allows merchandise carts to roll into the free refrigerated space at ground level.
In the illustrated embodiment, the cabinet module 11 includes a plurality of adjustable support assemblies on the bottom wall 20 for adjusting the cabinet to be level. These support assemblies are described more fully in U.S. patent application Ser. No. 17/031,129, filed Sep. 24, 2020, and U.S. patent application Ser. No. 17/480,827, filed Sep. 21, 2021, each of which is hereby incorporated by reference in its entirety. Cabinet modules can be supported in other ways without departing from the scope of this disclosure.
In an exemplary embodiment, the cabinet module 11 is equipped with one or more integrated cabinet systems suitable for particular merchandiser application requirements. For example, such cabinet systems may include one or more lighting systems 142 (shown schematically in
In the illustrated embodiment, the cabinet module 11 is configured for top-mounted refrigeration. However, this disclosure is not strictly limited to top-mounted systems. It is contemplated that refrigeration system modules could be mounted on the side or bottom or rear of the merchandiser depending on the customer/application needs. But again, in the illustrated embodiment, each refrigeration system module 12 is mountable on the top wall 18 for cooling the free refrigerated space of the cabinet 11. An upper shroud 26 may be installed along the perimeter of the top wall 18 above the doors 22 for concealing the refrigeration system module 12, accessing the controls, and/or adding lighting and other marketing graphics as desired. Suitably, the shroud 26 is a separate component of the refrigerated merchandiser kit 10 that is configured to be installed on the cabinet module 11 in the field. This maximizes free refrigerated space height while still allowing the cabinet module to fit through a standard-height man door.
The top wall 18 of the cabinet module 11 is generally configured to operably connect to each of one or more refrigeration system modules 12 so that each refrigeration system module can cool the interior of the cabinet. In the illustrated embodiment, the top wall 18 of the cabinet module 11 comprises separate inlet and outlet ports 30, 32 for each the refrigeration system module 12. The inlet port 30 is configured to impart cold refrigerated air from the respective refrigeration system module 12 into the cabinet interior, and the outlet port 32 is configured to return the warmer air that carries the product heat and moisture back to the respective refrigeration system module. In the illustrated embodiment, each supply air inlet 30 comprises a slot that is elongate in the widthwise direction of the cabinet and extends through the thickness of the top wall 18 at a location adjacent the back wall 16. Each return air outlet 32 likewise comprises a slot that is elongate in the widthwise direction and extends through the thickness of the top wall 18. Each return air outlet 32 is spaced apart in front of the corresponding supply air inlet 30 in the front-to-back direction. The inlet and outlet ports 30, 32, depicted in this embodiment define a path of cold and warm air. It is contemplated that these ports could be reversed to supply the cold air to the front duct and warm air to the rear duct depending upon the application.
The top wall 18 further comprises one or more integrated connection fittings for releasably and operably attaching one or more refrigeration system modules 12 to the cabinet module 11. In particular, the illustrated top wall 18 comprises a plurality of pre-formed holes 34 (e.g., screw holes) configured to receive removable fasteners (e.g., screws) which operably connect each refrigeration system module 12 to the cabinet module 11 (as discussed in further detail below). In one or more embodiments, for each refrigeration system module 12, the screw holes 34 comprise a first set of screw holes spaced apart in a first front-to-back line located on a first lateral side of the supply air inlet 30 and return air outlet 32 and a second set of screw holes spaced apart in a second front-to-back line located on a second lateral side of the supply air inlet and the return air outlet. Suitably, the screw holes 34 are arranged so that, when used to secure a refrigeration system module 12 to the cabinet module 11: (i) the refrigeration system is supported on top of the cabinet module; (ii) the refrigeration system is configured to direct supply air from an evaporator into the refrigerated interior through the supply air inlet 30; and (iii) the refrigeration system is configured to direct return air from the refrigerated interior through the return air outlet 32.
Referring to
In one or more embodiments, each return air plenum 38 extends along the underside of the top wall 18 from a front end portion end to a rear end portion. The front end portion of each return air plenum 38 defines one or more inlet openings or orifices that form an inlet through which return air is directed into the return air plenum. The rear end portion of the return air plenum 38 forms an outlet that opens to the return air outlet 32. Each return air plenum 38 generally defines the upper end of the free refrigerated space inside the interior of the cabinet module 11 and the bottom shelf 24 defines the opposite lower end of the free refrigerated space in the illustrated embodiment.
As can be seen the air flow passaging of the cabinet module is configured to direct cold refrigerated air downward along the back wall 18 from the supply air inlet 30 and then forward into the free refrigerated space in the interior of the cabinet. After absorbing heat and moisture from within the cabinet, return air is drawn upward generally at the front of the cabinet and then is directed to flow rearward along the top wall 18 and into the return air outlet 32. It will be appreciated that the particular arrangement of air flow passaging may vary from what is shown without departing from the scope of the disclosure. For example, instead of directing the air to flow back-to-front through the free refrigerated space, the merchandiser could be configured to direct the air to flow front-to-back or side-to-side through the free refrigerated space. While the primary thrust of this disclosure is directed to refrigerated cabinets, it is contemplated that a temperature control module could also be configured to warm or heat the interior space.
As explained more fully below, the illustrated refrigerated merchandiser kit 10 is configured so that no portion of the refrigeration system is located within the interior of the cabinet when the merchandiser 10′ is assembled. This enables the cabinet module 11 to provide heretofore unattainable usable merchandising space in a merchandiser capable of being delivered through a standard-height man door.
In the illustrated embodiment, the cabinet module 11 has a free refrigerated space height FRSH (
The illustrated cabinet module 11 also comprises a free refrigerated space depth FRSD (
As shown in
As explained above, the illustrated cabinet module 11 is configured to be fitted with a set of shelves 24 for holding product in a portion of the free refrigerated space.
In the illustrated embodiment, the back end of the shelf space is delimited by a rear guard 42 comprising an upright grill spaced apart in front of the front wall 40 of the discharge plenum 36 used to ensure proper air flow by preventing merchandise from being pushed backward into contact with the discharge plenum. Above each shelf 24, the shelf-space extends forward from the rear guard 42 to the front edge of the shelf, and vertically from the plane of the shelf to the plane of the above-adjacent shelf (or the bottom wall of the return air plenum 38 in the case of the top cantilevered shelf). As shown in
The very deep reach-in cabinet 11 described above is well-suited for delivery through a double man door doorway. But when only a single man door is available, it may be useful to construct the cabinet to have a lesser free refrigerated space depth and/or shelf depth. Regardless, embodiments of field-installable refrigerated merchandiser kits 10 in the scope of the disclosure enable efficient use of the overall space occupied by the installed merchandiser.
The space that a unit occupies can be thought of in at least two ways. Firstly, the space can be defined in terms of the “unit dimensions,” that is the exterior dimensions defined by the walls and doors of the cabinet independent of its environment. In that regard, referring to
A second way to conceptualize how much of the space occupied by a cabinet module 11 is usable is by comparing the free refrigerated space dimensions with the dimensions that the cabinet module occupies as installed in a building. For most refrigerated merchandiser kits of the prior art, these “occupied dimensions” are materially greater than the unit dimensions because cabinet modules of the prior art must be installed at substantial offset (e.g., greater than 3 inches in a front-to-back direction) from a backing structure against which the cabinet is positioned, e.g., a store wall or the back of an adjacent cabinet, due to piping, wiring, tubing, and a required area for heat to escape the condensing unit. However, in one or more embodiments, the illustrated refrigerated merchandiser 10 is configured to be installed and operated against a backing structure at zero offset from a backing structure. In certain embodiments, the cabinet module is configured to define an occupied volume defined by an occupied height extending from the floor to the top of the top wall, an occupied depth extending from the backing structure against which the cabinet is deployed to the front plane FP, and an occupied width extending from the outer face of one side wall 14 to the outer face of the other side wall. When installed at zero offset, these occupied dimensions of the illustrated cabinet module 11 are equal to the unit dimensions UH, UD, UW. In an exemplary embodiment, the occupied depth of the cabinet 11 is less than 40 inches. The occupied volume can be calculated as the occupied height (e.g., UH) times the occupied depth (e.g., UD) times the occupied width (e.g., UW). In one or more embodiments, the volume of the free refrigerated space is at least 60% of the occupied volume. Similarly, the free refrigerated space cross-sectional area is at least 60% of the occupied cross-sectional area measured as the occupied depth times the occupied height (e.g., at least 63%, at least 65%).
Another useful metric that demonstrates how efficiently the cabinet module 11 uses space compares the volume of the shelf space (e.g., the interior width IW of the cabinet module times the shelf space cross-sectional area SS depicted in
Referring to
In an exemplary embodiment, each prefabricated refrigeration system module 12 comprises a single refrigeration circuit that is hermetically sealed. Thus, no refrigeration connections are required to be made in the field. This substantially reduces the likelihood of refrigerant leaks during use of the refrigerated merchandiser 10′ in comparison with comparable field-installable merchandiser systems that require refrigeration connections to be made in the field. The inventors recognize that, when installing certain remote condensing units in the field, evacuation, access, and charging ports are used, and these create opportunity for refrigeration leaks and performance degradation due to non-condensable fluid entering the refrigeration system. In the merchandiser 10′, no access or service ports are provided in order to provide a truly hermetically sealed refrigeration module. In an exemplary embodiment, in lieu of service ports, the high and low side pressure transducers are integrated into the refrigeration system to output pressure signals as described in U.S. Provisional Patent Application Ser. No. 63/152,363, filed Feb. 23, 2021 and entitled ICE MAKER, which is hereby incorporated by reference in its entirety for all purposes. As explained therein, a local or remote display can be used to display pressure data from the pressure transducers for diagnostic purposes as needed. Although U.S. Provisional Patent Application Ser. No. 63/152,363 pertains particularly to the use of integrated pressure transducers in the hermetically sealed refrigeration system of a dedicated ice maker, it will be apparent that the same general type of pressure transducers can be used in the same general way in the hermetically sealed refrigeration system modules 12 discussed herein. It is also noted that, in this disclosure, the refrigeration module(s) 12 do not employ the use of a receiver or vessel for storing excess refrigerant, in contrast with remote refrigeration systems, which require receivers to account for the plethora of different locations, piping sizes, piping runs, and line sets that occur when the cabinets are connected to various configurations of condensing units.
In an exemplary embodiment, the refrigeration circuit comprises natural refrigerant such as r290. Those skilled in the art will recognize that use of such natural refrigerant requires compliance with certain laws and regulations, particularly laws and regulations defining maximum charge amounts. In one or more embodiments, the refrigeration system module 12 comprises one or more hermetically sealed refrigeration circuits comprising r290 refrigerant at a charge of less than or equal to 150 grams. In another embodiment, the refrigeration system module can comprise one or more refrigeration circuits that utilize other types of refrigerant and/or other charge amounts (e.g., 150 grams of charge or greater).
Each illustrated refrigeration system module 12 comprises a complete compression-driven refrigeration circuit including an evaporator assembly 50, a compressor 52, a condenser assembly 54, a drier 56, an expansion valve 58, and interconnecting tubing. It is also expressly contemplated that the prefabricated refrigeration system 12 can comprise more than one refrigeration circuit as part of the same module in certain embodiments. Those skilled in the art will be familiar with the basic components, functions, and operations of these components in a compression-driven refrigeration circuit. It is contemplated that other temperature control modules in the scope of this disclosure could provide heat and/or could use secondary refrigerant circuits to maintain the desired cabinet interior temperatures. As will be explained in further detail below, in the illustrated embodiment, each prefabricated refrigeration system module 12 (refrigeration system) comprises an independent temperature controller 68 configured to drive the refrigeration system based on a detected temperature.
In an exemplary embodiment, the compressor 52 of each refrigeration system is a variable speed compressor. As will be explained in further detail below, the use of a variable speed compressor is thought to enhance the implementation of multiple refrigeration system modules 12 on the same cabinet module 11 for cooling a common refrigerated space. It will be understood that fixed speed compressors can also be used in certain embodiments.
In the illustrated embodiment, the condenser assembly 54 (broadly, heat rejecting heat exchanger) comprises an air-cooled condenser unit including a condenser fan 60 configured to draw outside room ambient air across condenser coils 62. In certain embodiments, the condenser fan 60 can comprise a fixed speed fan or variable speed fan or a combination of both to meet application requirements. It is also contemplated that the prefabricated refrigeration system can comprise a water-cooled condenser unit in one or more embodiments.
The evaporator assembly 50 (broadly, heat absorbing heat exchanger) comprises evaporator coils 64 in which liquid refrigerant absorbs heat and changes to vapor. Other heat exchangers such as heating elements or secondary refrigerant/glycol coils or loops could also be used to change the temperature inside the free refrigerated space. The evaporator assembly 50 further comprises an evaporator fan 66 configured to draw return air from the cabinet module 11 across the evaporator coils 64 to cool the air before discharging it into the cabinet module through the supply air inlet 30. Like the condenser fan 60 described above, the evaporator fan 66 can be a fixed speed or variable speed or a combination of both to provide the cooling output that meets application requirements. The fans are used to transfer volumes of air from inside the conditioned space of the cabinet 11 to the cooling/heating module and also from the ambient surrounding to the cooling/heating module through the heat exchangers.
Various additional sensors and transducers used for monitoring the operating characteristics of the refrigeration system may also be employed. In one or more embodiments, the temperature controller 68 is configured to receive inputs from these sensors and transducers.
In one or more embodiments, the temperature controller 68 is configured to control the compressor 52 to selectively maintain refrigeration temperatures in a range of from −20° F. to 75° F. The temperature controller 68 may also be configured to control the speed or output of a variable speed condenser fan 60 and/or a variable speed evaporator fan 66 (discussed below) based on algorithms that perform pulldown operations, recovery operations, energy savings operations, or preventative maintenance operations. In certain embodiments, the refrigeration system module further comprises a wired (e.g. RS485) or wireless transceiver (e.g., a cellular modem, Bluetooth, Wifi, and other radio frequency devices) configured to provide communication between the merchandiser controller and a remote communication device. Exemplary ways of utilizing such remote communications are described in U.S. Pat. No. 9,863,694, which is hereby incorporated by reference in its entirety.
In general, the prefabricated refrigeration system modules 12 and the cabinet module 11 comprise mutual connection fittings configured to releasably and operatively connect the prefabricated refrigeration system module to the cabinet module for cooling the interior of the cabinet module and such that an entirety of the prefabricated refrigeration system module is on the exterior of the cabinet module. More particularly, the mutual connection fittings in the illustrated embodiment are configured to mount each refrigeration system 12 on the top wall 18 of the cabinet module 11 entirely above the top wall of the cabinet module for cooling the interior of the cabinet module. Preferably, each refrigeration system module 12 is configured to releasably and operably connect to the cabinet module 11 (e.g., the top wall 18) such that the refrigeration system module 12 can cool the interior of the cabinet when connected. Suitably, the mutual connection fittings also enable the refrigeration system modules 12 to be disconnected from the cabinet modules 11 so that the modules may be separately moved through a standard-height man door to another location as needed.
Referring to
The evaporator portion 72 forms the bottom wall of an insulated evaporator enclosure 76 that is broadly configured to enclose the evaporator assembly 50 and provide fluid communication with the supply air discharge plenum 36 and the return air plenum 38 of the cabinet module 11. The evaporator enclosure 76 is generally configured to separate the evaporator assembly 50 from the condenser assembly 54. Thus, the illustrated evaporator enclosure 76 includes an insulated front wall generally between the condenser portion 74 and the evaporator portion 72 of the base, which provides thermal separation between the evaporator assembly 50 and the condenser assembly 54. The illustrated evaporator enclosure 76 further includes left and right side walls and a back wall that, together with the front wall, define a 360° insulated perimeter around the evaporator assembly 50. The evaporator enclosure 76 further comprises a removable lid 78 that may be removed as required to access the evaporator assembly for service and maintenance.
The evaporator portion 72 of the base 70 defines a supply air outlet 80 and a return air inlet 82. In the illustrated embodiment, the supply air outlet 80 comprises a slot that is elongate in the widthwise direction of the base 70 and that extends through the thickness of the base at a location adjacent the back wall of the evaporator enclosure 76. The return air inlet 82 is likewise a slot that is elongate in the widthwise direction and is spaced apart in front of the supply air outlet 80. In other words, in the illustrated embodiment, the return air inlet 82 and supply air outlet 80 are spaced apart from one another in the front-to-back direction. The return air inlet 82 and the supply air outlet 80 are respectively sized and arranged for registration with the return air outlet 32 and the supply air inlet 30. As such, when the refrigeration system module 12 is operably connected to the cabinet module 11, the supply air outlet 80 provides fluid communication between the interior of the evaporator enclosure 76 and the supply air inlet 30, and the return air inlet 82 provides fluid communication between the interior of the evaporator enclosure and the return air outlet 32.
Suitably, the kit 10 comprises seals for sealing the interface between the top wall 18 of the cabinet module 12 and the base 70 of the refrigeration system module 12 around the supply air openings 30, 80 and the return air openings 32, 82. For example, one of the prefabricated refrigeration system module 12 and the cabinet module 11 suitably comprises a supply air gasket 84 configured to extend 360° about the supply air openings 30, 80 and another return air gasket 86 configured to extend 360° about the second return air openings 32, 82. In the illustrated embodiment, the prefabricated refrigeration system module 12 comprises a supply air gasket 84 on the lower surface of the base 70 which extends 360° about the supply air outlet. In addition, the prefabricated refrigeration system module 12 comprises a return air gasket 86 on the lower surface of the base 70 which extends 360° about the return air inlet 82. These seals alternatively could be installed on the upper surface of the cabinet module. In the illustrated embodiment, the gaskets 84, 86 comprise two separate pieces of compressible closed-cell foam. However, a single piece of compressible material and compressible material other than closed cell foam may also be used without departing from the scope of the disclosure. Alternatively, interlocking geometry of plastic could also be used to create the seal between refrigeration module and cabinet module.
Referring to
Referring to
Each rail 90 is formed from a generally U-shaped or J-shaped metal channel. As shown in
The adjustment flange 92 is configured to facilitate adjustment of the rail between a lowered position (
As shown in
The bottom web 94 of each rail 90 defines a set of integral attachment points 102 used for fastening the refrigeration system module 12 to the cabinet module 11 in an operative position. In particular, the bottom web 94 defines a plurality of screw holes 102 arranged for registration with the integral screw holes 34 of the top wall 18 of the cabinet module 11. Rear ones of the screw holes 102 align with mounting brackets 103 connected to the sides of the base (e.g., screwed to the side walls of the evaporator enclosure 76). Each refrigeration system module 12 is configured to be operatively connected to the cabinet module 11 by threadably advancing screws 105 mounting through each of the screw holes 102 formed in the bottom web of each rail 90 into a corresponding screw hole 34 on the top wall 18 of the cabinet module 11. The rear screws 105 are fastened to the top wall of the cabinet 11 through the mounting brackets 103.
In summary, the refrigerated merchandiser kit 10 comprises separate cabinet and refrigeration system modules 11, 12 that can be releasably and operably connected together using mutual connection features or fittings that are integrated into the modules. In the illustrated embodiment, the mutual connections fittings include supply air inlet and outlet openings 30, 80 and a supply air gasket 84 that are configured to align to provide substantially sealed fluid passaging from the downstream side of the evaporator assembly 50 to the supply air discharge plenum 36 of the cabinet 11. Similarly, the mutual connections fittings of the illustrated kit 10 include return air inlet and outlet openings 32, 82 and a return air gasket 86 that are configured to align to provide substantially sealed fluid passaging from the upper end of the refrigerated interior of the cabinet to the upstream side of the evaporator assembly 50. Still further, the mutual connection fittings of the illustrated kit 10 comprise corresponding sets of mechanical attachment points 34, 102 by which the refrigeration system module 12 is configured to be releasably fastened to the top wall 18 of the cabinet module 11 at the operative position, for example by threadably advancing screws 105 through the screw holes 102 of the refrigeration system module 12 into the screw holes 104 formed in the top wall 18 of the cabinet module 11.
A method of installing one or more refrigeration system modules 12 on the cabinet module 11 will now be briefly described. In an exemplary embodiment, the kit 10 comprises instructions for performing this method. Initially, the prefabricated cabinet module 11 and the refrigeration system module 12 are separately moved through a doorway to a desired location within a building. After removing any packaging materials, the technician can begin the process of loading the refrigeration system module 12 onto the cabinet module 11. The rails 90 of the prefabricated refrigeration system module 12 will initially be in the lowered positions (
As shown in
Referring to
Referring to
As can be understood in view of the foregoing, in one aspect, the present disclosure provides a large-capacity merchandiser 10′ that is configured to be cooled to refrigeration and freezer temperatures entirely by prefabricated refrigeration systems 12. More particularly, the present disclosure provides a large-capacity merchandiser 10′ with volumetric shelf space greater than 10,000 in3 (e.g., greater than 12,500 in3, greater than 15,000 in3, greater than 20,000 in3, greater than 25,000 in3, or even greater still) configured to be cooled to refrigeration and freezer temperatures entirely by hermetically sealed refrigeration systems charged with natural refrigerant at a charge level that complies with predominant worldwide regulatory standards. For example, in one or more embodiments, the present disclosure provides such a large-capacity merchandiser 10′ cooled entirely by a plurality of refrigeration systems 12 that run on r290 refrigerant at a charge of less than or equal to 150 g. To achieve such large capacity using only prefabricated, natural refrigerant refrigeration, the inventors have developed a new system for deploying multiple refrigeration systems 12 to cool the same common refrigerated space.
In the illustrated cabinet 11, the free refrigerated space is a single, contiguous refrigerated space. Throughout this disclosure, the term “common refrigerated space” is used to describe such a single, contiguous refrigerated space in a merchandiser 10′ that includes multiple refrigeration systems for cooling the same undivided (i.e., common) refrigerated space.
In general, refrigerated merchandisers 10′ in accordance with the present disclosure can incorporate a plurality of discrete refrigeration systems 12 for cooling a common refrigerated space, wherein each refrigeration system comprises an independent temperature controller 68 configured to control the respective refrigeration system independently of the other refrigeration systems. As explained above, each refrigeration system 12 comprises a separate refrigeration circuit, comprising at least a respective evaporator assembly 50, compressor 52, condenser assembly 54, expansion valve 58, and interconnecting tubing. Although exemplary embodiments of the refrigerated merchandiser 10′ use field-installable refrigeration system modules 12, it is contemplated that aspects of this disclosure pertaining to multiple independent temperature control and multiple refrigeration system integration can also be used in a fully self-contained refrigeration cabinet employing a plurality of refrigeration systems. In an exemplary embodiment, each independent temperature controller 68 is digital temperature controller (e.g., one of many suitable temperature controllers is a Dixell XR70CH temperature controller). However, other types of temperature controllers (e.g., pressure controllers, analog thermostats) may also be used in one or more embodiments.
As explained above, the illustrated cabinet 11 has a width UW and the discrete refrigeration systems 12 are configured to be operatively connected to the cabinet at a plurality of locations spaced apart along the width of the cabinet. Each refrigeration system module 12 comprises its own air temperature sensor 69 (illustrated schematically in
Referring to
As mentioned above, each refrigeration system 12 comprises a variable speed compressor 52. Each refrigeration system 12 further comprises an inverter 120 that connects the temperature controller 68 to the respective compressor 52 for controlling the speed of the compressor. In other words, each refrigeration system 12 comprises an inverter compressor. Each inverter 120 is operatively connected to the respective temperature controller 68 so that the temperature controller 68 can output a control signal to the inverter 120. The inverter 120 is configured to vary the frequency of alternating current output to the compressor 52 and thereby drive the compressor at a speed proportional to the alternating current frequency. This eliminates stop-start cycles and substantially moderates the inrush of current to the compressors 52 at startup. As will be explained in further detail below, the illustrated merchandiser 10′ is configured to run all of the refrigeration systems 12 from a single power input 122. Moderating the inrush of current at startup is critical to preventing the refrigerated merchandiser from tripping a circuit breaker or other current limiter on the premises.
Each independent temperature controller 68 is configured to adjust the speed of the variable speed compressor 52 based on the detected air temperature at the respective location. In one or more embodiments, a user can use a user interface connected to the temperature controller 68 to adjust a set point temperature for the refrigeration system 12. In the illustrated embodiment, the set point temperature of each refrigeration system 12 can be set independently via a respective user interface, but it is contemplated that other embodiments can use a common interface for all of the independent temperature controllers 68 to ensure that each of the independent temperature controllers has the same set point.
The temperature controllers 68 may employ various methods for independently controlling the speed of each variable speed compressor 52. In one example, for each individual refrigeration system 12, when the detected air temperature at the respective location is greater than the required temperature, the independent temperature controller 68 is configured to signal the variable speed compressor inverter 120 in the same way it would a single-speed compressor, and the inverter uses internal logic to set the speed of the compressor 52. This method is referred to as the “drop in” method. In the “drop in” method, the inverter 120 uses internal parameters, timers, and logic to determine the rate at which to run the variable speed compressor 52. For example, at a basic level, the inverter 120 can be configured to gradually increase the speed of compressor 52 as the temperature controller 68 continuously signal the inverter to provide cooling. The independent temperature controller 68 also communicates a defrost signal to the inverter 120. The timers, parameters, and response rates for each variable speed compressor 120 and inverter 52 are configured such that the multiple refrigeration systems 12 work in concert to uniformly cool the cabinet 11, and moreover, can make up for lost cooling capacity in the event that one of the refrigeration systems goes offline.
In another example, which may be referred to as “proportional” control mode, each independent temperature controller 68 has a defined “proportional control band,” e.g., a temperature range about the user-defined required temperature setting. When the detected air temperature at the respective location is greater than the required temperature settings plus the proportional band, the temperature controller 68 provides a frequency output to the variable speed compressor inverter 120, which communicates to the compressor 52 to run at its highest speed. As detected temperature decreases to be within the proportional control band, the temperature controller 68 reduces the frequency output proportionally. In response, the inverter 120 reduces the speed of the variable speed compressor 52. Additionally, during defrost, cycle starts, and cycle stops, the temperature controller 68 can output unique frequencies to the variable speed compressor inverter 120 to account for these transitory states. Of course, it will be understood that alternatively to a frequency output, a temperature controller 68 could provide a serial output to the variable speed compressor inverter for even more precise control and feedback. The serial control can gather information as to the status of the variable speed compressor 52 and inverter 120. Based on the mechanical systems' ability to reach and hold the required temperature setting, integral and derivative signals can be provided from the temperature controller 68 to the variable speed compressor inverter 120 to achieve the user defined temperature setting. It will be further understood that more complex algorithms, such as hybrids of the above-described “drop in” algorithm and “proportional” algorithm may be used by each independent temperature controller 68 to set the compressor speed.
By equipping each refrigeration system 12 with a variable speed compressor 52 independently controlled by the respective independent temperature controller 68, the illustrated refrigerated merchandiser 10′ builds in substantial redundancy that improves merchandising reliability in the event of a malfunction, particularly in the embodiment shown in which each refrigeration system 12 mounts atop the top wall 18 of the cabinet 11 entirely out of the cold space. In conventional refrigerated merchandisers, e.g., those of the hybrid refrigeration type, refrigeration repairs often require unstocking the cabinet 11 to access the refrigeration system. Furthermore, when there is a malfunction, it affects the entire cooling capacity of the merchandiser. The reduced temperatures cannot be maintained while the repair is made. By contrast, when one of the refrigeration systems 12 of the merchandiser 10′ has a malfunction, the malfunctioning unit can be repaired or replaced while the other refrigeration system(s) continues to provide cooling to the common refrigerated space. Moreover, the variable speed control algorithms executed by the independent temperature controllers 68 in the remaining refrigeration system(s) will automatically make up for a substantial portion of the lost cooling by increasing the compressor speed. Furthermore, because of the kitted, field-installable nature of the illustrated refrigeration system modules 12, any defective refrigeration system module can be replaced with a new or refurbished refrigeration system module in short order, without the involvement of any skilled tradesmen, and without any intrusion into the cold space.
Referring to
The main electrical box 124 is configured to route power and signals to the various systems of the merchandiser 10′. The main electrical box 124 includes one or more electrical panels 126, 128 configured to facilitate plug-in connections from the individual refrigeration units 12 and the cabinet 11
Referring to
Referring to
Referring to
Referring to
Suitably, each temperature controller 68 is configured to output a cabinet control signal to one or more cabinet systems, such as the cabinet lights 142 and/or the cabinet heaters 144. Each of the illustrated temperature controllers 68 controls a relay 166 that provides the cabinet control signal to the cabinet heaters 144. As shown, the multiple temperature controllers 68 are connected to the cabinet heaters 144 in parallel. At any point in time, if any one of the temperature controllers 68 is outputting a cabinet control signal to the cabinet heaters 144, the cabinet heaters will be active. Various methods and algorithms for controlling cabinet heaters of a refrigerated merchandiser 10′ are known and may be used without departing from the scope of the disclosure. In one embodiment each temperature controller defines a duty cycle for the cabinet heaters and outputs the control signal to independently control the cabinet heaters according to the defined duty cycle. In the illustrated embodiment, the cabinet lights 142 are controlled by a separate manual switch 168. But it is also contemplated that the cabinet lights 142 may be controlled by the temperature controllers 68 in one or more embodiments. For example, the multiple temperature controllers 68 may be coupled to the cabinet lights 142 in parallel so that, if any one of the temperature controllers is outputting a cabinet control signal to the cabinet lights 142 at a given point in time, the cabinet lights will be active. In the illustrated embodiment, the main electrical box 124 hardwires the heated pressure relief valve 145 to the power supply 122 such that a heater on the relief valve runs at 100% duty cycle. It will be understood that the heated pressure relief valve may draw power in other ways without departing from the scope of the disclosure.
In an exemplary embodiment, the door sensor circuit 140 comprises a plurality of door sensors (e.g., one door sensor for each door 22) connected together in series, and the door sensor circuit is configured to communicate with the temperature controllers 68 in parallel. Hence, if any of the door sensors is outputting a signal indicating that the respective door 22 is open, the door sensor circuit 140 transmits a signal to the all of the temperature controllers 68. The temperature controllers 68 are suitably configured to control the refrigeration system based on the signals from the door sensor circuit 140. In one embodiment, each temperature controller 68 is configured to turn off the respective evaporator fan 66 in response a signal from the door sensor circuit 140 indicating that a door 22 is open. In certain embodiments, the temperature controllers 68 are configured to monitor the time that the door sensor circuit 140 continuously outputs a signal indicating that a door is open. Each temperature controller 68 is configured to (i) turn off the evaporator fan 66 for an initial interval of time, and (ii) after the initial interval of time, turn the evaporator fan back on. This ensures that cooling is provided in the event of a door sensor fault or a scenario in which one of the doors 22 is stuck open.
In the illustrated embodiment, each refrigeration system 12 comprises a defrost heater 172. The refrigerated merchandiser 10′ is configured to periodically execute a defrost cycle in each refrigeration system 12 in which the respective temperature controller 68 turns on the defrost heater 172 and turns off the evaporator fan 66 for a period of time. In general, the refrigerated merchandiser 10′ is configured to execute the defrost cycles in each refrigeration system at different times. More particularly, each independent temperature controller 68 independently executes defrost cycles as a function of the respective system's run time (e.g., compressor run time). The run time of each of the refrigeration systems 12 will inherently vary because each system runs on an independent temperature control based on a detected temperature at a unique location. Each temperature controller 68 is configured to periodically execute a defrost cycle in which the temperature controller turns on the defrost heater 172 and turns off the evaporator fan 66 for a period of time. Each independent temperature controller 68 is configured to monitor an elapsed run time of the respective refrigeration system 12 since a last defrost and to initiate a subsequent defrost cycle when the elapsed run time exceeds a defined defrost interval.
In an exemplary method of repairing the refrigerated merchandiser 10′, a defective one of the refrigeration system modules 12 is initially removed from the cabinet 11. Removal of the defective refrigeration system module 12 does not require the involvement of any specialized tradesmen. Rather, any technician can simply unscrew the rails 90 from the top wall 18 of the cabinet 11, disconnect the power cord 154 from the high voltage receptacle 136, disconnect the cable from the plug-in connector 152, and then lift the defective refrigeration system 11 off of the top wall 18 of the cabinet. While the defective refrigeration system module 12 is removed, the common refrigerated space in the cabinet 11 is continuously cooled with one or more remaining (operational) refrigeration system modules 12.
When the defective refrigeration system module 12 is removed, it exposes one or more holes in the cabinet 11 (e.g., the cold air inlet 30 and the return air outlet 32). In an exemplary embodiment, after the defective refrigeration system module 12 is removed, the holes 32 are plugged to minimize loss of cold air through the holes. For example, in an exemplary embodiment, the technician plugs the holes 30, 32 with one or more pre-fabricated bung seals (not shown) formed from resiliently compressible sealing material such as closed cell foam and sized to be sealingly received in one or both of the holes 30, 32.
While the defective refrigeration system 12 is removed, the independent temperature controllers 68 of the remaining refrigeration system(s) 12 will automatically increase the speed of the compressor(s) 56 over time to make up for the missing cooling. Thus, it can be seen that various technical features of the merchandiser 10′ (e.g., multiple independent temperature control, variable speed compression, top-mounted refrigeration with no intrusion into cold space, simplified/unskilled mechanical and electrical connections between refrigeration system modules and cabinet, etc.) work in concert to enable repair of a defective refrigeration system 12 without loss of merchandise.
Before installing an operational refrigeration system, the technician unplugs the holes 30, 32. In some cases, the technician may be able to quickly repair the refrigeration system module 12 after it has been removed to make it operational again. In such cases, the technician can reinstall the same refrigeration system module 12 on the cabinet module 11 after it has been repaired. In another embodiment, the technician installs an operational replacement refrigeration system module 12 in place of the defective system.
Again, no skilled tradesmen are required to install the operational refrigeration system 12 onto the cabinet 11. Any technician can simply mechanically mount the system onto the top wall using the rails 90 as described above, plug the power cord 154 into a high voltage receptacle 136 in the main electrical box 124, plug the previously unplugged cable into the connector 152, and then the independent temperature controller 68 of the newly installed system will begin independently cooling the common refrigerated space. It can be seen that the illustrated refrigerated merchandiser, with its entirely top-mounted refrigeration systems and multiple independent temperature control redundancy, can be repaired without unpacking merchandise from the reach-in cabinet.
As can be seen, the illustrated refrigerated merchandiser kit 10 is field-installable through a standard-height man entry doorway yet still provides a very large-capacity refrigerated merchandiser 10′ once deployed. The merchandiser 10′ maximizes packable space by placing all refrigeration components outside of the cabinet 11. In addition, by providing an integrated condensate removal system 104, the merchandiser 10′ can be placed in-store with its back tightly positioned against an adjacent structure. Moreover, the merchandiser kit 10 can be installed and put into service without any need of specialized or certified tradesmen such as refrigeration technicians, plumbing technicians, or electricians. Even when multiple refrigeration system modules 12 are employed to cool the very larger common refrigerated space defined within the cabinet module 11, he entire installation process requires only turning a small number of screws and plugging the unit's electrical cord(s) into a standard electrical receptacle(s) along with standard latching electrical connector(s). The ease of installation enabled by the illustrated field-installable merchandiser kit 10 is unparalleled by any refrigerated cabinet of comparable size known to the inventors.
These advantages can pay substantial dividends in the event that the merchandiser should need to be moved to another building or location. The refrigeration system module(s) 12 can be separated from the cabinet module 11 using the same basic techniques in reverse, without need of certified tradesmen. Then the separated modules can be moved through a standard-height man door to a new location where the merchandiser 10′ can be redeployed using the same techniques as before.
Moreover, the kit 10 can provide hermetically sealed refrigeration system(s) 12 in combination with a cabinet 11 with an internal capacity on the order of, or greater than, cabinets that conventionally could only be realized using remote refrigeration systems. This is believed to substantially reduce the likelihood of refrigerant loss and generally improve installation, reliability, serviceability, and energy efficiency in comparison with conventional refrigerated merchandisers of comparable size.
Furthermore, the illustrated kit 10 provides the benefit of positioning the entire refrigeration system 12 outside of the cabinet interior, which provides substantial improvements in serviceability because no merchandise needs to be removed or unpacked from the cabinet in order to reach any component of the refrigeration system for servicing or maintenance.
Certain exemplary embodiments of freezers, refrigerated merchandisers, and field-installable refrigerated merchandiser kits in accordance with the present disclosure are configured to automatically equalize the pressure between the interior and exterior of the cabinet. It is well-known in the refrigeration industry that pressure differentials between the inside and outside of a refrigerated cabinet can have undesirable effects. For example, when the pressure inside a cabinet is less than the pressure outside, it creates a vacuum on the doors. When the doors are well-sealed, it can be difficult to break the vacuum. The force required to open the door can be excessive, making the merchandiser less user-friendly than would be preferred. Various ways of addressing this problem have been proposed in the past. For example, some have proposed to incorporate a door handle mechanism that breaks the door seal when a user tries to open the door. More commonly it has been suggested to incorporate a pressure relief valve system into the refrigerated cabinet that acts passively to automatically equalize the pressures inside and outside the merchandiser by opening in response to any substantial pressure differential between the inside and outside of the cabinet.
The present inventors see the advantages of employing such a pressure relief valve system but believe that current pressure relief valve systems have undesired drawbacks. For example, the inventors believe that current pressure relief valve systems indiscriminately direct moist outside air onto chilled interior surfaces of the merchandiser, which over time, creates a buildup of frost that is not easy to remediate. Additionally, existing pressure relief valve systems are not well-suited to the large-volume modular merchandiser kits of the type described above because they are not deployed in such a way as to account for the differences in air volume and duty cycle of the various refrigerator cabinet modules. As explained more fully below, the inventors have developed a novel pressure relief valve system that addresses at least these problems by incorporating heated pressure relief valves directly into the evaporator enclosure.
An exemplary embodiment of a freezer or refrigerated merchandiser 10′ (broadly, a refrigerated storage device) in accordance with the present disclosure comprises a refrigeration system (e.g., a prefabricated refrigeration system module) generally indicated at reference number 12′, which is shown separately from the cabinet 11 in
The refrigeration system 12′ is the same as refrigeration system 12, except for an added pressure relief valve system described below. It is to be understood therefore that all elements of the refrigeration system 12 described above are included in the refrigeration system 12′. When the same parts are discussed below, parts of the refrigeration system 12′ are given the same reference number as the corresponding parts of the refrigeration system 12, followed by a prime symbol.
The refrigeration system 12′ includes a pressure relief valve 210′ configured to automatically open in response to pressure of the interior of the cabinet 11 being less than pressure of the exterior of the cabinet, whereby the pressure relief valve is configured to equalize pressure between the interior and the exterior of the cabinet module. When the pressure relief valve 210′ opens in this scenario, outside air (including moisture) is imparted into the refrigeration system 12′. As explained more fully below, the pressure relieve valve system illustrated here is configured to cool the entering air as soon as it enters the refrigeration system module 12′ through the pressure relief valve 210′. The proposed system can effectively dehumidify and ultimately freeze the moisture from the outside air within the refrigeration module 12′ because the air inside the refrigeration system module is colder than 32° F. The now-colder and drier air exits the refrigeration system 12′ and is passed into the refrigerated merchandiser 10′. By lowering the heat content and thus dehumidifying and freezing the moisture of the outside air inside of the refrigeration system 12′, the outside air that entered through the pressure relief valve 210′ has been conditioned in a manner that additional heat and moisture is not provide to the interior space of the refrigerated merchandizer 10′.
In certain embodiments, the pressure relief valve 210′ is also configured to automatically open in response to pressure of the interior of the cabinet module 11 being greater than pressure of the exterior of the cabinet module. In this scenario, cold air from inside the merchandiser 10′ flows out of the merchandiser through the valve 210′ to equalize the pressures.
The valve 210′ automatically closes when pressure inside and outside the cabinet 11 is substantially equal. Note that in the cross sections of
In an exemplary embodiment, the pressure relief valve 210′ is heated to prevent frost from forming inside the pressure relief valve. More particularly, the pressure relief valve 210′ comprises a dedicated valve heater 211′ (shown schematically) configured to prevent frost from forming inside the pressure relief valve. Suitably, the pressure relief valve 210′ comprises an electrical resistance heater 211′ disposed in thermal communication with the valve passage and valve member and configured to run continuously or at a selectable duty cycle at low wattage so that airborne moisture never frosts anywhere inside the valve. The selectable duty cycle for the valve heater 211′ is independent of the evaporator defrost cycle. In one suitable embodiment, the pressure relief valve 210′ comprises a heated pressure relief valve of the general type described in U.S. Pat. No. 10,731,912, which is hereby incorporated by reference in its entirety. Other types of heater pressure relief valves could also be used without departing from the scope of the disclosure.
As explained above, the refrigeration system 12′ comprises an evaporator enclosure 76′ and an evaporator assembly 50′ received in the evaporator enclosure. The evaporator enclosure 76′ includes one or more insulated walls that thermally insulate the interior of the evaporator enclosure from the exterior environment of the merchandiser 10′. In addition, the evaporator enclosure 76′ includes a supply air outlet 80′ and a return air inlet 82′ through which the evaporator assembly 50′ moves refrigerated air in the manner described above. In one or more embodiments, at least one insulated wall of the evaporator enclosure 76′ comprises an insulation panel 220′ and a sheet metal liner 222′ defining the interior surface of the evaporator enclosure. The illustrated refrigeration system 12′ is configured to mount atop a separate cabinet module 11 (discussed above) in modular fashion and hence includes insulated walls on all sides of the evaporator enclosure 76′. But it will be understood that this disclosure is not strictly limited to modular merchandiser kits. So therefore, in one or more embodiments, the present disclosure contemplates an evaporator enclosure that is received inside the cabinet in the refrigerated space. In such an embodiment, the evaporator enclosure will still include at least one insulated wall, e.g., the at least one insulated wall may comprise a section of the external cabinet wall adjacent to the evaporator assembly. An evaporator enclosure suitably comprises ports 80′ 82′ for drawing return air across the evaporator assembly and discharging refrigerated air into the main storage space of the merchandiser. As explained more fully below, the pressure relief valve 210′ is configured to be mounted in one insulated wall of an evaporator enclosure 76′, referred to hereinafter as the “relief valve support wall” 230′, so that the pressure relief valve is located near the evaporator assembly 50′ and is pointed generally toward the evaporator so that outside air flowing through the pressure relief valve 210′ is directed toward the evaporator. When the pressure relief valve 210′ opens, and the heat content and moisture are processed in the refrigeration system 12′, the conditioned air becomes in fluid communication between the interior of the cabinet 11 and the exterior of the cabinet via the ports 80′, 82′.
The evaporator assembly 50′ comprises evaporator coils 64′ in which liquid refrigerant absorbs heat and changes to vapor. The evaporator assembly 50′ further comprises an evaporator fan 66′ configured to draw return air from the cabinet 11 across the evaporator coils 64′ to cool the air before discharging the cooled air into the cabinet. In one or more embodiments, the evaporator assembly 50′ further comprises a plurality of heat transfer fins 233′ disposed across the evaporator coils 64′. In the illustrated embodiment, the heat transfer fins 233′ are capped by first and second end plates 212′ on opposite end portions of the evaporator coils 64′. The evaporator coils 64′ have a return bend to hairpin turn-to-turn coil width CW, a coil height CH, and a coil depth CD. The evaporator enclosure 76′ has an inner enclosure width IEW in the widthwise direction of the coils, an inner enclosure height IEH in the heightwise direction of the coils, and an inner enclosure depth IED in the depthwise direction of the coils. The inner enclosure width IEW, the inner enclosure height IEH, and the inner enclosure depth IED are respectively greater than the coil width CW, the coil height CH, and the coil depth CD such that the evaporator coils 64′ fit inside the evaporator enclosure.
One insulated wall of the evaporator enclosure 76′ comprises the relief valve support wall 230′. In an exemplary embodiment, the relief valve support wall 230′ extends generally in a plane parallel to the coil height CH and coil depth CD, but this is not strictly necessary. The relief valve support wall 230′ defines a relief valve hole 232′ for receiving the pressure relief valve 210′. The relief valve hole 232′ extends through the entire thickness of the relief valve support wall 230′, forming a passage through the insulation panel 220′ and the sheet metal liner 222′. The relief valve hole 232′ is aligned with the evaporator assembly 50′ so that the relief valve hole mounts the pressure relief valve 210′ for directing outside air toward the evaporator assembly when the pressure relief valve automatically opens in response to the pressure of the interior of the cabinet module being less than the pressure of the exterior of the cabinet module. The relief valve hole 232′ is oriented so that the pressure relief valve 210′ has a flow axis FA along which outside air flows through the relief valve into the evaporator enclosure 76′. In the illustrated embodiment, the flow axis FA is generally parallel to the coil width CW, generally intersects a lower section (e.g., lower half or lower third) of the coil height CH, and generally intersects a central portion (e.g., middle third) of the coil depth CD. It will be appreciated that pressure relief valves can have other locations without departing from the scope of the present disclosure. The inventors specifically contemplate relocating the relief valve hole 232′ more upstream so that the flow axis FA intersects an upstream section (e.g., upstream half or upstream third) of the coil depth CD to facilitate more interaction between the air entering through the valve 210′ and the evaporator (and thereby facilitate more pre-conditioning of the air) before the air is discharged through the supply air outlet 80′. As explained more fully below, the illustrated refrigeration system 12′ comprises a baffle adjacent the outlet of the valve that redirects air entering along the flow axis FA to flow depthwise toward the port 82′ before reversing course to cross the coils 64′ toward the outlet port 80′. Thus, in
The refrigeration system 12′ comprises a frosting chamber 242′ in the evaporator enclosure 76′. The frosting chamber 242′ is immediately adjacent to the evaporator assembly 50′ such that the frosting chamber is cooled by the evaporator assembly. In the illustrated embodiment, the frosting chamber 242′ and the evaporator assembly 50′ are side-by-side in the direction of the coil width CW. The illustrated frosting chamber 242′ comprises three sides defined by the evaporator assembly end plate 212′ (which opposes the pressure relief valve 210′), the sheet metal liner 222′ of the relief valve support wall 230′, and a metal span wall 243′ spanning between the evaporator assembly end plate and the relief valve support wall. The metal span wall 243′ comprises a first vertical edge margin secured to the relief valve support wall 230′ and an opposite second vertical edge margin secured to the end plate 212′. The metal end plate 212′ and the sheet metal liner 222′ define opposite sides of the frosting chamber 242′, and the metal span wall 243′ defines a third side of the frosting chamber 242′ transverse to the two opposing sides. Thus, the sheet metal liner 222′, the metal span wall 243′, and the end plate 212′ together define three contiguous, generally rectangular sides of the frosting chamber. The metal span wall 243′ and the evaporator assembly end plate 212′ form a baffle for redirecting directing air entering along the flow axis FA to flow depthwise toward the port 82′.
The fourth side of the frosting chamber 242′ (or a portion of one of the four sides of the frosting chamber) is preferably open to define an open side outlet 244′ that allows outside air to flow out of the frosting chamber after moisture frosts in the frosting chamber. In the illustrated embodiment, the top wall of the evaporator enclosure 76′ substantially encloses the top of the frosting chamber 242′ and the evaporator drain pan 106′ is located immediately below the bottom of the frosting chamber such that the path of least resistance for outside air to flow out of the frosting chamber 242′ is through the open side outlet 244′. Hence, in the illustrated embodiment, the frosting chamber 242′ (in particular the baffle formed by walls 212′, 243′) is configured to direct most of the outside air that enters through the pressure relief valve 210′ to flow out of the frosting chamber through the open side outlet 244′. Here, the open side outlet 244′ makes up the side of the chamber 242′ opposite the span wall 243′.
The open side outlet 244′ is also located at the upstream end of the frosting chamber 242′ in the direction of refrigeration air flow across the evaporator assembly 50′. As explained above, the evaporator fan 66′ is configured to draw return air from the return air port 82′ and discharge air through the supply air port 80′. Hence, the direction of refrigeration air flow across the evaporator runs generally parallel to the coil depth CD in the direction extending from the return air port 82′ to the supply air port 80′. The open side outlet 244′ is spaced apart from the span wall 243′ of the frosting chamber 242′ in the upstream direction relative to refrigeration air flow across the evaporator coils 64′. Accordingly, the outside air leaves the frosting chamber 242′ through the open side outlet 244′ at the upstream side of the evaporator coils 64′, where it can be drawn across the evaporator coils by the fan 66′. Outside air entering along the flow axis FA first turns roughly 90 degrees toward the outlet 244′ in a width-depth plane to pass the baffle and then turns roughly 180° in the depth-width plane to flow across the coils 64′ as driven by the evaporator fan.
The frosting chamber 242′ is cooled by the evaporator assembly 50′ so that the frosting chamber provides a chilled interior frosting surface on which moisture in the outside air directed into the merchandiser through the pressure relief valve 210′ freezes as frost. In the illustrated embodiment, each of the sheet metal liner 222′, the metal end plate 212′, and the metal span wall 243′ define respective sides of the chilled interior frosting surface. The metal end plate 212′ defines a first side of the chilled frosting surface opposing the outlet of the pressure relief valve 210′. The metal end plate 212′, and thus the first side of the chilled frosting surface, extends in a plane parallel to the coil height CH and coil depth CD and has a height greater than or equal to the coil height CH and a width greater than or equal to the coil depth CD. The metal liner 222′ defines a second side of the chilled frosting surface opposite the first side. The metal liner 222′, and thus the second side of the chilled frosting surface, extends in a plane parallel to the coil height CH and coil depth CD and has a height greater than or equal to the coil height CH and a width greater than or equal to the coil depth CD. The metal span wall 243′ forms a third side of the chilled frosting surface perpendicular (broadly, transverse) to the first and second sides. The metal span wall 243′, and thus the third side of the chilled frosting surface, has height greater than or equal to the coil height CH and spans the gap between the first and second sides of the chilled frosting surface. Accordingly, it can be seen that the chilled frosting surface generally defines a three-sided chamber 242′ beside the evaporator assembly 50′ that spans the entire height CH and depth CD of the evaporator coil 64′. Thus, in one or more embodiments, the frosting chamber 242′ has a chamber height CHH greater than or equal to the coil height and a chamber depth CHD greater than or equal to the coil depth CD. Each of the metal end plate 212′, the metal interior surface 222′, and the metal span wall 243′ extends the full chamber height CHH.
During normal use, the evaporator assembly 50′ cools the chilled frosting surface to a freezing temperature (e.g., a temperature below 0° C.). When the pressure relief valve 210′ opens to allow moist outside air into the merchandiser 10′, the air initially contacts the chilled frosting surface so that a portion of the moisture freezes as frost on the chilled frosting surface. The baffle is configured to deflect air from the valve 210′, which creates a degree of turbulence that promotes interaction with the chilled frosting surface. The inventors believe that the increased interaction with the chilled frosting surface promotes freezing the moisture in the air as frost on the chilled frosting surface. For example, the moist outside air enters the frosting chamber 242′ flowing generally along the flow axis FA and contacts the end wall 212′ of the evaporator assembly 50′. Some of the moisture in the air freezes as frost on the inside surface of the end wall 212′. Some of the air deflects off of the end wall 212′ toward the opposing sheet metal liner 222′, where more of the moisture freezes as frost. Other air deflects off of one or both of the end plate 212′ and the liner 222′ toward the span wall 243′, where still more moisture freezes as frost. Some of the air will repeatedly deflect off of the various facets of the chilled frosting surface, whereby moisture in the air is progressively removed as frost on the chilled interior frosting surface. Eventually the outside air flows out of the frosting chamber, predominantly through the open side outlet 244′. More moisture in the air can freeze as frost on the evaporator coils 64′ and the fins 233′ as the evaporator fan 66′ draws air from the frosting chamber outlet 244′ across the evaporator coils.
It can be seen that the frosting chamber 242′ removes a substantial amount of moisture before allowing the outside air to reach the remainder of the refrigerated merchandiser 10′. Furthermore, the frosting chamber 242′ directs much of the outside air to flow across the evaporator coils 64′ before interacting with any other part of the merchandiser 10′, so yet more of the moisture in the air freezes as frost on the coils and the fins 233′. The inventors believe that this arrangement is beneficial because it reduces that amount of frost that forms in other parts of the merchandiser (e.g., in the interior storage space or on the refrigerated merchandise). In one or more embodiments, the pressure relief valve 210′ is configured to direct the outside air into the interior of the cabinet through the frosting chamber 242′ such that a majority of the moisture in the outside air introduced through the pressure relief valve freezes in the refrigeration system 12′ as frost on the chilled interior frosting surface of the frosting chamber.
As explained above, the prefabricated refrigeration system 12′ comprises a defrost heater 172′ and an evaporator drain pan 106′. The evaporator drain 106′ includes a first section 106A′ below the evaporator assembly and a second section 106B′ below the frosting chamber 242′. The drain pan 106′ has a width DW that is greater than the coil width CW′ so that the evaporator drain pan can receive moisture that melts off of both the evaporator coil 64′ and the frosting chamber 242′. In the illustrated embodiment, the defrost heater 172′ is located immediately below the evaporator coil 64′ and has a width equal or greater to the coil width CW. The defrost heater 172′ can overlap the frosting chamber 242′ in the widthwise direction.
The merchandiser 10′ is configured to periodically execute a defrost cycle whereby the defrost heater 172′ melts frost formed on the evaporator coil 64′. During each defrost cycle, the heat produced by the defrost heater 172′ also melts frost formed in the frosting chamber 242′. In other words, the frosting chamber 242′ is located in relation to the defrost heater 172′ such that frost formed on the chilled interior frosting surface defrosts and drains into the evaporator drain pan 106′ during the defrost cycles. Because the evaporator drain pan 106′ is located below the frosting chamber 242′ as well as the evaporator coil 64′, the frost that melts from the frosting chamber 242′ during each defrost cycle will drain through the evaporator drain pan 106′ and be evaporated using the condensate removal system described above.
Accordingly, in one aspect, the present disclosure provides a refrigerated merchandiser or freezer that includes an evaporator with automatic defrost, a heated pressure relief valve, and a frosting chamber strategically located between the pressure relief valve and the evaporator so that a majority of the moisture in the outside air that enters the merchandiser through the pressure relief valve frosts on the chilled surfaces of the frosting chamber and on the evaporator, where it can easily be removed during periodic defrost cycles. The dedicated valve heater prevents frost from ever forming inside the pressure relief valve so that the valve remains operational at all times. And the frosting chamber collects frost at a location where it can easily be removed by the defrost heater and condensate removal system. Thus, this disclosure addresses undesirable pressure differences between the interior and exterior of the cabinet without creating a substantial frosting issue inside the cabinet and on the refrigerated merchandiser.
In another aspect, this disclosure provides an elegant method for equipping a large-volume modular refrigerated merchandiser 10′ with a desired amount of pressure equalization capacity for equalizing the pressure between the interior and the exterior of the merchandiser. Conventional pressure relief valve systems are fitted to the refrigerated cabinet. But the inventors have recognized that fabrication and inventory can be streamlined for modular merchandiser systems by locating the pressure relief valve on the prefabricated refrigeration system modules instead of the cabinet module.
As explained above, certain embodiments of the cabinet module 11 are configured to operatively connect to a plurality of prefabricated refrigeration system modules 12′. These cabinets 11 comprise a plurality of pairs of ports, each pair comprising one supply air inlet 30 and one return air outlet 32. Each pair of ports 30, 32 corresponds to a mounting location for one prefabricated refrigeration system module 12′. A merchandiser 10′ is formed from a kit 10 by installing a prefabricated refrigeration system module 12′ onto the top of the cabinet at each pair of ports 30, 32.
The number of pairs of ports 30, 32 formed in the cabinet module 11 is a function of the interior volume of the cabinet module. Each prefabricated refrigeration system module 12′ has a cooling capacity rating, and the number of pairs of ports 30, 32 is selected so that the combined refrigeration system modules 12′ provide the desired amount of cooling for the merchandiser 10′.
The inventors have recognized that, just as required cooling capacity scales proportionally with interior cabinet volume, negative pressure differential between the inside and outside of the cabinet 11 affects the force required to open the doors 22 proportionally to the interior volume of the cabinet. That is, all other things being equal, for a given negative pressure differential, the force required to open the door 22 will be greater if the interior volume of the cabinet 11 is greater. Thus, the inventors believe that it is important to scale the pressure relief capacity proportionally with the interior volume of the cabinet.
The inventors believe that locating the pressure relief valves 210′ on the prefabricated refrigerated system modules 12′, instead of on the cabinet 11, provides an elegant way to ensure the pressure relief capacity is always sufficient for a modular refrigerated merchandiser of any size. Each cabinet module 11 is equipped with the number of pairs of ports 30, 32 corresponding to the number of prefabricated refrigeration system modules 12′ that provide sufficient cooling capacity for the cabinet. By locating the pressure relief valves 210′ on the prefabricated refrigeration system modules 12′, whenever the required number of prefabricated refrigeration system modules are installed on the cabinet module 11, the required number of pressure relief valves 210′ are simultaneously installed on the merchandiser 10′. Once installed, each pressure relief valve 210′ is configured to open in response to pressure of the interior of the refrigerated merchandiser cabinet 11 being less than pressure of the exterior of the refrigerated merchandiser cabinet whereby the pressure relief valves of the plurality of refrigeration systems 12′ equalize the pressure of the interior of the refrigerated merchandiser cabinet with the pressure of the exterior of the refrigerated merchandiser cabinet. Hence, adequate pressure equalization capacity is automatically provided by virtue of the required number of prefabricated refrigeration system modules 12′ being installed on the cabinet module 11.
The manufacturer is not required to manufacture and maintain an inventory of cabinet modules with different numbers of pressure relief ports. This is advantageous because it allows the same cabinet modules 11 to be used for different refrigeration applications by simply selecting the desired prefabricated refrigeration system modules 12, 12′ for a given application. For example, it may be that, when a merchandiser is to be used solely as a fresh food refrigerator, no pressure relief systems are required. A cabinet module 11 of the appropriate size can be coupled to one or more prefabricated refrigeration system modules 12 for fresh food use, which may be devoid of any pressure relief valves. The assembled merchandiser 10′ will have no pressure relief valves because none are required for the application. But the same cabinet module 11 can also be used to hold frozen foods such as ice cream, where a pressure relief system is desired. Refrigeration system modules 12′ including pressure relief valves 210′ can be installed on the same cabinet module 11′ to provide the desired pressure relief capacity for a frozen food application.
When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.
As various changes could be made in the above products and methods without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.