Patent Application
20230204277
The present disclosure generally relates to a self-contained reach in refrigerator, such as a refrigerated display case or merchandiser.
Various restaurant, retail, and medical establishments employ commercial refrigerators to keep cold-stored goods at chilled or frozen (broadly, below-ambient) temperatures. Some commercial refrigerators are self-contained units having factory-installed refrigeration systems integrated with a storage unit. Some commercial refrigerators employ reach-in cabinets. Energy-efficiency and reliability are important characteristics of self-contained reach-in refrigerators.
In one aspect, a self-contained reach-in refrigerator comprises a cabinet defining a product space. A self-contained refrigeration system is connected to the cabinet. The self-contained refrigeration system comprises an evaporator, a compressor, a condenser, an expansion device, and interconnecting tubing. A defrost heater is in thermal communication with the evaporator for selectively defrosting the evaporator. A drain pan is below the evaporator. A thermally conductive bridge member provides thermal conduction between the defrost heater and the drain pan.
In another aspect, a self-contained reach-in refrigerator comprises a cabinet defining a product space having a front-to-back depth, a width, and an upper end. A self-contained refrigeration system is connected to the cabinet. The self-contained refrigeration system comprises an evaporator, a compressor, a condenser, an expansion device, and interconnecting tubing. An evaporator fan is configured to draw air from the product space across the evaporator to cool the air and discharge cooled air into the product space. A defrost heater is in thermal communication with the evaporator for selectively defrosting the evaporator. An upper wall in the cabinet defines the upper end of the product space. The upper wall includes a drain pan section below the evaporator, a fan section extending forward from the drain pan section, and a rear lip extending upward from a rear end of the drain pan section. The evaporator fan is supported over the fan section to draw air from the product space through the fan section. A support member is fastened to the rear lip. The support member is separate from the cabinet and configured to support the upper wall within the cabinet.
Other aspects will be in part apparent and in part pointed out hereinafter.
Corresponding parts are given corresponding reference characters throughout the drawings.
Referring now to
The illustrated self-contained reach-in refrigerator 110 comprises an upright reach-in cabinet 112 made up of a set of insulated walls that separate part of the interior of the cabinet from the exterior or ambient environment of the cabinet. The cabinet 112 comprises a pair of side walls 116 spaced apart along a width of the cabinet, a top wall 118 and a bottom support 120 spaced apart along a height of the cabinet, and a back wall 122 running heightwise and widthwise along a back side of the cabinet.
The cabinet 112 defines a product space 124 inside the cabinet. The side walls 116 define the lateral sides of the product space. The self-contained reach-in refrigerator 110 further comprises a lower wall 126 that defines the bottom end of the product space 124 and an upper wall 128 that defines the top end of the product space. In the illustrated embodiment, the lower wall 126 comprises insulation that thermally insulates the product space 124 from a condenser chamber 130 below the product space. By contrast, the upper wall 128 is not insulated, yet it is configured define the top end of the product space 124 and to provide division between the product space and an evaporator plenum 132. The illustrated upper wall 128 has several features that are believed to contribute to improved energy efficiency and reliability in the self-contained reach-in refrigerator 110, as will be described in further detail below. Although the illustrated self-contained reach-in refrigerator 110 comprises a condenser chamber 130 below the product space 124 and an evaporator plenum 132 above the product space, it will be understood that reach-in refrigerators could have other configurations (e.g., with evaporator and condenser both positioned above or below the product space) without departing from the scope of the disclosure.
The illustrated cabinet 112 comprises a single hinged door 134 for selectively opening and closing a doorway (broadly, a front opening) to the product space. It will be understood, however, that aspects of the present disclosure can be employed on refrigerator cabinets comprising multiple doors, sliding doors, or air curtains, in lieu of the single hinged door 134 of the illustrated embodiment.
In certain embodiments, the self-contained reach-in refrigerator 110 is configured for use as a display case, or more broadly, a merchandiser. Those skilled in the art will recognize that such merchandisers comprise doors 134 with insulated glass providing a line of sight to the product space 124 through the door. Typically, the insulated glass is heated to prevent fog from forming on the glass during opening and closing of the refrigerator. It is contemplated that a self-contained reach-in refrigerator 110 can comprise heated door glass in one or more embodiments. But in certain embodiments, such as embodiments that will not be deployed in tropical environments, the inventors contemplate that the glass door 134 can be non-heated to minimize energy consumption. When the door glass is non-heated, the inventors contemplate applying an unpowered anti-fog film to the door glass to inhibit condensation from obstructing the view through the door glass. In certain embodiments, the anti-fog film can be a modified cellulose diacetate film, such as Clarifoil AF1 or AF1000 film. In an exemplary embodiment, the door 134 comprises a triple-pane insulated glass unit (“IGU”), with argon filling the two spaces between the three glass panes (see
Referring to
Referring to
The evaporator 148 comprises an evaporator coil (broadly, a heat exchanger) in which liquid refrigerant absorbs heat and changes to vapor, thereby absorbing heat and moisture from the product space. The illustrated evaporator coil 148 is situated in the evaporator plenum 132 above the upper wall 128. An evaporator fan 152 (which can be fixed speed or variable speed) is configured for moving air across the evaporator 148 so that the evaporator absorbs heat from the air to cool the interior storage space 124. The evaporator fan 152 is broadly configured to draw return air from the product space 124 through an inlet 160 in the upper wall 128 and move the air downstream across the evaporator 148 to cool the air. The fan 152 moves the cooled air downstream from the evaporator 148 to an outlet 162 through which the cooled air is discharged into the product space 124. In the illustrated embodiment, the outlet 162 is located along the back wall 122 of the cabinet 112, and the inlet 160 to the evaporator plenum 132 is spaced apart forwardly from the discharge plenum toward the front the cabinet 112. However, it will be understood that the air plenums could have other arrangements (e.g., the outlet could be along one lateral side with the inlet opening adjacent to the opposite lateral side) without departing from the scope of the disclosure.
The illustrated evaporator 148 has an upright configuration that is thought to facilitate efficient heat transfer, yielding improvements in the overall energy efficiency of the self-contained reach-in refrigerator 110 as compared with certain self-contained reach-in refrigerators of the prior art utilizing evaporators that in cross-section are of greater dimension in the cross-wise direction than they are in height. The evaporator 148 has a bottom end and a top end spaced apart along an evaporator height EH, and an evaporator front end (broadly, upstream end) and an evaporator rear end (broadly, downstream end) spaced apart along a front-to-back evaporator depth ED (broadly, a crosswise dimension). The evaporator 148 is shaped and arranged in the evaporator plenum 132 such that the evaporator height EH is greater than the front-to-back evaporator depth ED. For example, in one or more embodiments, the evaporator height EH is at least 125% of the front-to-back evaporator depth ED (e.g., about 150%). The front-to-back evaporator depth ED is broadly a “crosswise dimension” of the evaporator 148 in the direction of flow through the evaporator plenum 132. Although the illustrated crosswise dimension ED runs front-to-back, it will be understood that the crosswise dimension of the evaporator can alternatively be a lateral dimension or otherwise, depending on how the evaporator plenum is arranged in relation to the cabinet.
The evaporator 148 comprises a plurality of widthwise coil sections 164 spaced apart along the evaporator height EH and the front-to-back evaporator depth ED. The plurality of widthwise coil sections 164 are arranged in a plurality of vertical coil section columns 166 spaced apart along the front-to-back evaporator depth ED (broadly, spaced apart along the crosswise dimension of the evaporator). The evaporator 148 comprises a first number of vertical coil section columns 166 and a second number of widthwise coil sections 164 in each vertical coil section column, wherein the first number is less than the second number. In an exemplary embodiment, the second number is at least 125% of the first number (e.g., about 150%). In the illustrated embodiment, the first number is 4 and the second number is 6.
The self-contained reach-in refrigerator further comprises a defrost heater 170 in thermal communication with the evaporator 148 for selectively defrosting the evaporator. The defrost heater 170 selectively heats the evaporator 148 to melt frost on the evaporator coil, thereby forming liquid condensate that falls from the evaporator. As explained more fully below, the self-contained reach-in refrigerator 110 comprises a drain pan 172 below the defrost heater to receive the liquid condensate that melts during defrost. A drain conduit 174 fluidly connects the drain pan 172 to the condensate tray 156 in the condenser chamber 130 below the product space 124 such that the defrosted water drains into the condensate tray 156 where it can be evaporated by heat supplied via the discharge loop 158. In the illustrated embodiment, the defrost heater 170 comprises an electrical resistance heating element, but other embodiments can use other heating elements without departing from the scope of the disclosure.
Referring to
As shown in
To uncover the evaporator 128, the evaporator fan 152, and the defrost heater 170, the user only needs to remove the removable fasteners 177 (e.g., <12 removable fasteners) and then take out the one-piece upper wall 128. As explained above, in an exemplary embodiment, the removable fasteners 177 are machine screws rather than sheet metal screws. The inventors have found that the way of mounting the illustrated upper wall 128 to the refrigerated cabinet 112 offers several advantages over conventional reach-in cabinet configurations. Firstly, the machine screws allow the upper wall 128 to be removed and reinstalled numerous times without failure, whereas prior art sheet metal screw fasteners are prone to stripping with repeated use. Additionally, prior art self-contained reach-in refrigerators often required removal of well in excess of 12 screws and removal of more than one wall piece to fully access the evaporator, evaporator fan, and/or defrost heater. So by contrast, there are substantial improvements in ease-of-access and serviceability with the illustrated upper wall 128.
In the illustrated embodiment, side walls 184 of the evaporator plenum 132 are suspended from the top wall 118 at locations spaced apart inboard of the cabinet side walls 116 and the rails 182. Thus, in the illustrated embodiment, the evaporator plenum 132 has a width that is less than the overall width of the inside of the cabinet 112. Gaskets are fitted onto the bottom edges of the side walls 184 for being sealingly compressed between the side walls and the upper wall 128 when the upper wall is installed. It will be understood that the evaporator plenum can extend the full width of the cabinet in one or more embodiments.
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The drain pan section 172 comprises a front end portion joined to the fan section 176 at the crease 180 and a rear end portion from which a rear lip 200 of the upper wall 128 extends upward in a generally vertical plane. The rear lip 200 forms the rear wall of the drain pan whose bottom is formed by the drain pan section 172. The front end portion and the rear end portion of the drain pan section 172 are spaced apart along a front-to-back depth of the drain pan. The drain pan section 172 further comprises a left side portion and a right side portion spaced apart along a width of the drain pan. In the illustrated embodiment, the drain pan section 172 extends along the full width of the evaporator plenum 132. The drain pan section 172 comprises a drain opening 202 at the rear end portion centrally located between the left side portion and the right side portion. A fitting of the drain conduit 174 is received in the drain opening 202 (see
The drain pan section 172 is generally configured to guide water that settles anywhere along the front-to-back depth and lateral width of the bottom of the drain pan to flow toward the drain opening 202. More particularly, the drain pan section 172 is situated below the evaporator 148 such that any liquid condensate that falls off of the evaporator during defrost will land on the drain pan section and flow from wherever it lands toward the drain opening 202. In other words, the drain pan section 172 is shaped and arranged to minimize the extent to which water can settle and pool anywhere along the drain pan section 172—other than at the drain opening. In general, the drain pan section 172 slopes downward as the drain pan section extends front-to-back from the front end portion to the rear end portion. Further, the illustrated drain pan section 172 is configured to slope downward as the drain pan section extends widthwise from the right side portion to the drain opening 202 and to slope downward as the drain pan section extends widthwise from the left side portion to the drain opening.
In the illustrated embodiment, the drain pan section comprises left and right diagonal gutter creases 204, 206. The left gutter crease 204 slopes downward from the front left corner of the drain pan section 172 to the drain pan opening 202, and the right gutter crease 206 slopes downward from the front right corner of the drain pan section to the drain pan opening. The gutter creases 204, 206 define three planar triangular segments 208, 210, 212 along the drain pan section 172. The left gutter crease 204 defines a boundary between a central triangular segment 208 and a left triangular segment 210, and the right gutter crease 206 defines a boundary between the central triangular segment and a right triangular segment 212. The triangular segments 210, 212, 214 slope toward the gutter creases 204, 206 such that water on any of the triangular segments is directed to flow toward the gutter creases and the drain pan opening 202.
The central triangular segment 208 is defined by the widthwise front edge of the drain pan section 172 and the left and right gutter creases 204, 206. The central triangular segment 208 extends in a plane sloping front to back at a slope angle SA2. The central triangular segment does not have widthwise slope. In one or more embodiments, the slope angle SA2 (FIG. 12) is in an inclusive range of from 2° to 20° (e.g., in an inclusive range of from 3° to 10°). In certain embodiments, the slope angle SA2 is less than the slope angle SA1.
The left triangular segment 210 defines the front-to-back left edge of the drain pan section 172 and has a front edge defined by the left gutter crease 204 and a rear edge defined at a joint (e.g., crease) between the drain pan section 172 and the rear lip 200. The left triangular segment 210 extends in a plane that is non-parallel to the plane of the central triangular segment 208. The left triangular segment 210 slopes front-to-back at a front-to-back slope angle SA3 (
The right triangular segment 212 defines the front-to-back right edge of the drain pan section 172 and has a front edge defined by the right gutter crease 206 and a rear edge defined at a joint (e.g., crease) between the drain pan section 172 and the rear lip 200. The right triangular segment 212 extends in a plane that is non-parallel to the planes of the central triangular segment 208 and the left triangular segment 210. The right triangular segment 212 slopes front-to-back at a front-to-back slope angle SA5 (
The inventors have found that the three-segment drain pan section 172 can yield improvements in refrigeration performance and reliability. Conventional drain pans in this type of refrigerator include bottom walls that slope in a single plane. The inventors have found that the conventional type of single-plane drain pan can allow water to settle in certain locations. Moreover, the settled water can freeze on the drain pan, and once ice begins to form, it can propagate, eventually forming a substantial mass of solid ice that can block the drain conduit and lead to a malfunction that requires servicing. By contrast, the inventors have discovered that the left and right gutters 204, 206 of the illustrated drain pan section 206 substantially prevent any water from settling on the drain pan and thus limit the possibility for ice to form on the drain pan. Furthermore, the conventional single-plane drain pan design employs a significant number of seams sealed by silicone sealant. The three-segment drain pan section 172 eliminates some of the silicone joints and minimizes the extent to which silicone joints are likely to contact water. Those skilled in the art will recognize that this reduces the points of potential leakage failure in the drain pan.
Referring to
The thermally conductive bridge member 220 conducts heat from the defrost heater 170 to the drain pan 172 during every defrost cycle. This melts ice that forms on the drain pan 172 and thus keeps the drain pan substantially clear of ice. It will be understood that, conceptually, a thermally conductive bridge member can be used to melt ice on any drain pan below an evaporator with a defrost heater. Thus adaptations of the thermally conductive bridge member 220 can be used to provide conductive heat transfer to drain pans of any shape and configuration without departing from the scope of the disclosure.
In one or more embodiments, the upper wall 128 is made of aluminum and the thermally conductive bridge member 220 is also made of aluminum (broadly, the upper wall and the conductive bridge member are separate components made from the same type of thermally conductive material). The inventors have found that aluminum provides good thermal conduction for the application. Moreover, the inventors prefer to form the upper wall 128 and bridge member 220 from the same material to inhibit galvanic corrosion.
It can be seen that in the illustrated embodiment, the rear lip 200 of the upper wall 128 is formed in separate left and right sections spaced apart by a central gap aligned with the drain opening 202. This construction enables the entire upper wall 128 to be formed from a single monolithic piece of sheet metal. More particularly, this construction enables the drain pan section 172 to include left and right triangular segments 210, 212 that slope in opposing directions. However, the inventors have recognized that the gap provided between the left and right sections of the rear lip 200 is a point of weakness under load. For example, when the drain pan 172 is filled with liquid the upper wall 128 may deform under the added weight. In the illustrated embodiment the rear section 224 of the thermal bridge member 220 forms a support member, separate from the cabinet 112, that is fastened to the rear lip 200 to support the upper wall 128 within the cabinet. It is contemplated that, in one or more embodiments, a support member can support the upper wall in the same manner as the rear section 224 of the thermal bridge member 220, wherein the support member is not part of a thermal bridge to the defrost heater. Generally speaking, a suitable support member 224 comprises a plate fastened face-to-face with the rear lip 200. Such a plate 224 can be fastened face-to-face with both the left and right sections of the rear lip 200. In an exemplary embodiment, the plate 224 has a first portion in face-to-face contact with the left section of the rear lip 200, a second portion in face-to-face contact with the right section of the rear lip, and extends continuously from the first portion to the second portion across the gap formed in the rear lip.
When introducing elements of the present disclosure 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 disclosure 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 disclosure, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.
