US20220175154A1

US20220175154A1 - Display refrigerators and freezers

Info

Publication number: US20220175154A1
Application number: US17/497,693
Authority: US
Inventors: Paul McAndrew; Ian Turner
Original assignee: Aerofoil Energy Ltd
Current assignee: Aerofoil Energy Ltd
Priority date: 2019-04-09
Filing date: 2021-10-08
Publication date: 2022-06-09
Also published as: MA55601A; GB2584602A; GB2584602B; WO2020208347A1; CN113924451A; EP3953649A1; GB201905036D0; AU2020272549A1

Abstract

A display refrigerator or freezer comprises a refrigerated storage space. Air in the refrigerated storage space is separated from air exterior to the display refrigerator or freezer by an air curtain established by one or more fans which blow air towards one or more air outlets via a cooling heat exchanger and which recover air in the air curtain via one or more air inlets for recirculation to the one or more air outlets. The refrigerated storage space has a base shelf. One or more air inlet ducts are arranged between the one or more air inlets and the one or more fans such that the air recovered via the one or more air inlets is directed by the one or more air inlet ducts towards the one or more fans. The one or more air inlet ducts, in combination with at least a portion of the base shelf, define at least a portion of a cavity beneath the base shelf, the cavity being sealed from the air recovered via the one or more air inlet.

Description

The invention relates to display refrigerators and freezers which can either have doors comprising transparent windows or have an open front (i.e. do not include a door). The invention also relates to methods of and kits for modifying such display refrigerators and freezers.
Display refrigerators and freezers are commonly used in retail environments, such as supermarkets, to store and display products, such as meat and dairy products, which must be kept at lower than ambient temperatures. The open/transparent front of such refrigerators and freezers makes it easy for customers to view the products being displayed.
Display refrigerators and freezers have an air curtain, which is established by blowing cold air across the front of the refrigerator or freezer. The air curtain issues from an air outlet at the top of the refrigerator or freezer towards an air inlet at the bottom of the refrigerator or freezer. The air inlet recovers air from the air curtain and recirculates it to the air outlet via a cooling heat exchanger and fan.
One problem with this type of refrigerator or freezer is that some of the warm air (i.e. air that is warmer than the refrigerated interior) drawn into the air inlet by the fan tends to dwell under the base shelf of the refrigerator or freezer instead of passing through to the heat exchanger. This causes warming of the underside of the base shelf. Heat subsequently conducts through the base shelf creating “hot-spots” which can warm food products on the shelf. To combat this problem, refrigerator/freezer manufacturers typically increase the cooling effect provided to the entire refrigerator or freezer, which increases energy consumption.
A further inefficiency associated with this type of refrigerator or freezer is that the air passing into the fan is usually turbulent and uneven. This results in air passing through only some of the heat exchanger, which reduces the efficiency of the refrigerator or freezer, again increasing energy consumption.
Display refrigerators sometimes include insulation on the underside of the base shelf. However, this insulation is usually provided at the rear of the refrigerator, above the cooling heat exchanger (evaporator), and does not prevent warm air from transferring heat into the refrigerator at the front of the base shelf.
Rather, this insulation is typically provided to prevent freezing of products at the rear of the base shelf, which can occur due to the coldness of the cooling heat exchanger (evaporator) underneath the rear of the base shelf.
Accordingly, there is a need in the art to increase the energy efficiency of refrigerators and freezers of this type.
In accordance with a first aspect of the invention, there is provided a display refrigerator or freezer comprising a refrigerated storage space, air in the refrigerated storage space being separated from air exterior to the display refrigerator or freezer by an air curtain established by one or more fans which blow air towards one or more air outlets via a cooling heat exchanger and which recover air in the air curtain via one or more air inlets for recirculation to the one or more air outlets, the refrigerated storage space having a base shelf; one or more air inlet ducts arranged between the one or more air inlets and the one or more fans such that the air recovered via the one or more air inlets is directed by the one or more air inlet ducts towards the one or more fans; wherein the one or more air inlet ducts, in combination with at least a portion of the base shelf, define at least a portion of a cavity beneath the base shelf, the cavity being sealed from the air recovered via the one or more air inlets.
The display refrigerator or freezer can be a display refrigerator or freezer comprising an interior space and a door, wherein the door comprises a transparent window and separates the interior space from air external to the display refrigerator or freezer. For example, the display refrigerator or freezer can be a full glass door freezer. Alternatively, the display refrigerator or freezer can be a display refrigerator which is open at the front (i.e. does not have a door). The cooling heat exchanger may be situated at the base of the display refrigerator or freezer or at the rear of the display refrigerator or freezer.
The provision of the air inlet ducts of the first aspect of the invention achieves at least two technical effects. Firstly, the air inlet ducts seal a cavity underneath the base shelf, ensuring that the warm air recovered via the one or more air inlets cannot dwell against the underside of the base shelf, which reduces heat transfer from the warm air to the base shelf and then to the food products. This allows refrigerator/freezer manufacturers to reduce the cooling effect provided to the entire refrigerator or freezer, and thus reduce energy consumption. Further, the air inlet ducts provide a direct and even channel for air to pass through to the fans. This reduces turbulence and makes the airflow through the fans more even, making the refrigerator or freezer more efficient.
In some embodiments, the display refrigerator or freezer includes the same number of air inlet ducts and fans and each air inlet duct is arranged to direct air towards a respective fan only (for example, the display refrigerator or freezer may include a single air inlet duct and a single fan, and the single air inlet duct directs air towards the single fan). This may result in a particularly even airflow through the fans.
In some embodiments, the cavity is evacuated (i.e. contains a vacuum). In other embodiments, the cavity contains air. It has been found that both a vacuum and air are more effective at insulating the base shelf from the warm air entering through the air inlet than insulation material such as fibreglass or mineral wool or polyurethane foam. In some embodiments, insulation material such as fibreglass or mineral wool or polyurethane foam may be provided under a portion of the base shelf (in the cavity and/or outside the cavity).
In some embodiments, the display refrigerator or freezer further comprises one or more outlet ducts arranged between the one or more fans and the cooling heat exchanger such that air blown by the one or more fans is directed towards the cooling heat exchanger. In some embodiments, the cavity is defined at least in part by a portion of the one or more outlet ducts. The addition of an outlet duct provides the function of a) providing a more even distribution of air over the cooling heat exchanger (e.g. evaporator), increasing efficiency; and optionally b) forming, in part, the cavity which insulates the front of the base shelf from warm air entering from the air inlet.
In some embodiments, the cavity is defined (for example defined in its entirety) by a) a combination of the base shelf and the one or more air inlet ducts; b) a combination of the base shelf, one or more air inlet ducts and one or more outlet ducts; c) a combination of the base shelf, one or more air inlet ducts and insulation material; d) a combination of the base shelf, one or more air inlet ducts, one or more outlet ducts and insulation material; or e) a combination of the base shelf, one or more air inlet ducts and one or both of the side walls of the fridge.
In some embodiments, a sealant (for example a silicone sealant) is provided to seal the cavity. This has the advantage that the insulation effect provided by the cavity is maximised because warm air cannot enter the cavity at all. It should be understood that even without a sealant, only minimal amounts of warm air can enter the cavity, which would still be effective in preventing warming of the underside of the base shelf.
In accordance with a second aspect of the invention, there is provided a kit for retrofitting one or more air inlet ducts to a display refrigerator or freezer, wherein the display refrigerator or freezer comprises a refrigerated storage space, air in the refrigerated storage space being separated from air exterior to the display refrigerator or freezer by an air curtain established by one or more fans which blow air towards one or more air outlets via a cooling heat exchanger and which recover air in the air curtain via one or more air inlets for recirculation to the one or more air outlets, the refrigerated storage space having a base shelf; the kit comprising one or more air inlet ducts for directing air recovered by the one or more air inlets towards the one or more fans; wherein the one or more air inlet ducts are shaped to terminate at the one or more air inlets at a first end, such that on installation, in combination with at least a portion of the base shelf of the refrigerator, the one or more air inlet ducts form at least a portion of a cavity beneath the base shelf, the cavity being sealed from air recovered via the one or more air inlets.
In some embodiments, the one or more air inlet ducts are shaped to terminate at the one or more fans at a second end. This may improve air flow to the fans.
In accordance with a third aspect of the invention, there is provided a display refrigerator or freezer comprising: a refrigerated storage space, air in the refrigerated storage space being separated from air exterior to the display refrigerator or freezer by an air curtain established by one or more fans which blow air towards one or more air outlets via a cooling heat exchanger and which recover air in the air curtain via one or more air inlets for recirculation to the one or more air outlets; one or more outlet ducts arranged between the one or more fans and the cooling heat exchanger such that air blown by the one or more fans is directed towards the cooling heat exchanger.
The outlet duct provides a more even distribution of air over the cooling heat exchanger (e.g. evaporator).
In some embodiments, the display refrigerator or freezer includes the same number of outlet ducts and fans, wherein each outlet duct is arranged to direct air from a respective fan only (for example, the display refrigerator or freezer may include a single outlet duct and a single fan, and the single outlet duct directs air from the single fan). This may result in a particularly even airflow from the fan or fans.
In accordance with a fourth aspect of the invention, there is provided a method of modifying a display refrigerator or freezer, wherein the display refrigerator or freezer comprises a refrigerated storage space, air in the refrigerated storage space being separated from air exterior to the display refrigerator or freezer by an air curtain established by one or more fans which blow air towards one or more air outlets via a cooling heat exchanger and which recover air in the air curtain via one or more air inlets for recirculation to the one or more air outlets, the refrigerated storage space having a base shelf; the method comprising: arranging one or more air inlet ducts between the one or more air inlets and the one or more fans such that the air recovered via the one or more air inlets is directed by the one or more air inlet ducts towards the one or more fans such that the one or more air inlet ducts, in combination with at least a portion of the base shelf, define at least a portion of a cavity beneath the base shelf, the cavity being sealed from the air recovered via the one or more air inlets.
In some embodiments, the method comprises arranging the same number of air inlet ducts between the air inlet or inlets and the fans as the number of fans, such that each air inlet duct is arranged to direct air onto a respective fan only. (For example, the method may comprise arranging only one air inlet duct between the air inlet(s) and the fan, if the display refrigerator or freezer comprises only a single fan). This may result in a particularly even airflow through the fans.
In some embodiments, the method further comprises evacuating the cavity. In other embodiments, the method comprises allowing the cavity to be filled with air. It has been found that both a vacuum and air are more effective at insulating the base shelf from the warm air entering through the air inlet(s) than insulation material.
In some embodiments, the method further comprises arranging one or more outlet ducts between the one or more fans and the cooling heat exchanger such that air blown by the one or more fans is directed towards the cooling heat exchanger. The one or more outlet ducts may be arranged such that the cavity is defined at least in part by a portion of one or more outlet ducts. The addition of one or more outlet ducts provides the function of a) providing a more even distribution of air over the cooling heat exchanger (e.g. evaporator), increasing efficiency and optionally b) forming, in part, the cavity which insulates the front of the base shelf from warm air entering from the air inlet.
In some embodiments, the method comprises arranging the one or more air inlet ducts and optionally the one or more outlet ducts and/or insulation material such that the cavity is defined (for example defined in its entirety) by a) a combination of the base shelf and the one or more air inlet ducts; b) a combination of the base shelf, one or more air inlet ducts and one or more outlet ducts; c) a combination of the base shelf, one or more air inlet ducts and insulation material; d) a combination of the base shelf, one or more air inlet ducts, one or more outlet ducts and insulation material; or e) a combination of the base shelf, one or more air inlet ducts and one or both of the side walls of the fridge.
In some embodiments, the method comprises providing a sealant (for example a silicone sealant) to seal the cavity. This has the advantage that the insulation effect provided by the cavity is maximised because warm air cannot enter the cavity at all. It should be understood that even without a sealant, only minimal amounts of warm air can enter the cavity, which would still be effective in preventing warming of the underside of the base shelf.
In accordance with a fifth aspect of the invention, there is provided a method of modifying a display refrigerator or freezer, wherein the display refrigerator or freezer comprises a refrigerated storage space, air in the refrigerated storage space being separated from air exterior to the display refrigerator or freezer by an air curtain established by one or more fans which blow air towards one or more air outlets via a cooling heat exchanger and which recover air in the air curtain via one or more air inlets for recirculation to the one or more air outlets, the method comprising arranging one or more outlet ducts between the one or more fans and the cooling heat exchanger such that air blown by the one or more fans is directed towards the cooling heat exchanger.
In some embodiments, the method comprises arranging the same number of outlet ducts between the fans and the cooling heat exchanger as the number of fans, such that each outlet duct is arranged to direct air from a respective fan only. For example, where the display refrigerator or freezer includes only a single fan, a single outlet duct may be arranged between the said fan and the cooling heat exchanger. This may result in a particularly even airflow from the fans.
In accordance with a sixth aspect of the invention, there is provided a kit for retrofitting one or more outlet ducts to a display refrigerator or freezer, wherein the display refrigerator or freezer comprises a refrigerated storage space, air in the refrigerated storage space being separated from air exterior to the display refrigerator or freezer by an air curtain established by one or more fans which blow air towards one or more air outlets via a cooling heat exchanger and which recover air in the air curtain via one or more air inlets for recirculation to the one or more air outlets; the kit comprising one or more outlet ducts for directing air from the one or more fans towards the cooling heat exchanger such that air blown by the one or more fans is directed towards the cooling heat exchanger; wherein the one or more outlet ducts are shaped to terminate at the cooling heat exchanger at a first end.
In some embodiments, the one or more outlet ducts are shaped to terminate at the one or more fans at a second end. This may improve air flow from the one or more fans to the cooling heat exchanger.
In accordance with a further aspect of the invention, there is also provided a display refrigerator or freezer which includes features of both the first aspect of the invention and the third aspect of the invention (i.e. which includes both air inlet ducts and outlet ducts). The features indicated as optional in respect of either or both the first and third aspects of the invention are also optional in this further aspect of the invention.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 shows a side cross-section of the bottom portion of a display refrigerator according to the first aspect of the invention.

FIG. 2 shows a schematic view of a display refrigerator according to the first aspect of the invention from underneath the base shelf of the refrigerator.

FIG. 3 shows a schematic view of the bottom portion of a display refrigerator according to the first aspect of the invention from above the bottom shelf of the refrigerator.

FIG. 4 shows a side cross-section of the bottom portion of a display refrigerator according to the third aspect of the invention.

FIG. 5 shows a schematic view of a display refrigerator according to the third aspect of the invention from underneath the base shelf of the refrigerator.

FIG. 6 shows a schematic view of the bottom portion of a display refrigerator according to the third aspect of the invention from above the bottom shelf of the refrigerator.

FIG. 1 shows a side cross-section of the bottom portion of a display refrigerator 100. The display refrigerator 100 has a refrigerated storage space 102 that is maintained at a lower than ambient temperature. Within the refrigerated storage space 102, there is a base shelf 116. Various embodiments may have one, two, three, four, five or any number of additional shelves (not shown) disposed above the base shelf, which may be flat, may be at an angle or may be mixture of angled and flat shelves. A typical angle for the angled storage shelves is 20°, however shelves at other angles may be used, as long as the product being refrigerated does not slide off the shelves. The display refrigerator 100 establishes an air curtain 106 by fans 108 within the display refrigerator 100 which blow cold air towards an air outlet (not shown), out of the air outlet to form the air curtain 106, the air from which is recovered by the fans 108 through an air inlet 114. Air inlet ducts 118 arranged between the air inlet 114 and the fans 108 direct the warm air recovered through the air inlet 114 towards the fans 108. The air inlet ducts 118 in combination with a portion of the base shelf 116 defines a cavity 120. Air in the cavity 120 is sealed from the warm air recovered by the air inlet 114. This means that the relatively warm air recovered by the air inlet 114 is separated from the base shelf 116, thus avoiding warming of the underside of the base shelf 116. This has the effect that the refrigerator can operate at a lower power to maintain a required temperature in the storage space 102, decreasing energy consumption. Further, the presence of the air inlet 114 causes a reduction in the turbulence of the air passing into the fans 108 which increases the efficiency of the display refrigerator 100, again decreasing energy consumption required to maintain the required temperature in the storage space 102. Air directed by the air inlet ducts 118 to the fans 108 is recirculated by the fans 108 to the air outlet via a cooling heat exchanger 112 within the display refrigerator 100. The cooling heat exchanger 112 maintains the recirculated air (and hence the air blown through the air outlet to form the air curtain 106) at a desired temperature. The desired temperature is chosen to be lower than ambient and acts to prevent cold air in the refrigerated storage space 102 from mixing with warm air exterior to the refrigerator 104.
FIG. 2 shows a schematic view of the same display refrigerator 100 shown in FIG. 1 from underneath the bottom of the display refrigerator 100. FIG. 3 shows a schematic view of the bottom portion of the same display refrigerator 100 shown in FIGS. 1 and 2 from above the bottom shelf of the refrigerator. These views show the shape of the air inlet ducts 118 in more detail.
FIG. 4 shows a side cross-section of the bottom portion of a display refrigerator 100. The display refrigerator 100 has a refrigerated storage space 102 that is maintained at a lower than ambient temperature. Within the refrigerated storage space 102, there is a base shelf 116. Various embodiments may have one, two, three, four, five or any number of additional shelves (not shown) disposed above the base shelf, which may be flat, may be at an angle or may be mixture of angled and flat shelves. A typical angle for the angled storage shelves is 20°, however shelves at other angles may be used, as long as the product being refrigerated does not slide of the shelves. The display refrigerator 100 establishes an air curtain 106 by fans 108 within the display refrigerator 100 which blow cold air towards an air outlet (not shown), out of the air outlet to form the air curtain 106, the air from which is recovered by the fans 108 through an air inlet 114. Fans 108 within the display refrigerator 100 recirculate the warm air recovered through the air inlet 114 to the air outlet via a cooling heat exchanger 112. Outlet ducts 122 arranged between the fans 108 and the cooling heat exchanger 112 ensure that air blown by the fans 108 is directed towards the cooling heat exchanger 112. This ensures that air passes more evenly through the cooling heat exchanger 112 which increases the efficiency of the display refrigerator 100, decreasing energy consumption.
FIG. 5 shows a schematic view of the same display refrigerator 100 shown in FIG. 4 from underneath the bottom of the display refrigerator 100. FIG. 6 shows a schematic view of the bottom portion of the same display refrigerator 100 shown in FIGS. 4 and 5 from above the bottom shelf of the refrigerator. These views show the shape of the outlet ducts 122 in more detail.
It should be understood that although the air inlet ducts and outlet ducts are shown in separate exemplary figures above, the invention also includes further embodiments where the display refrigerator or freezer includes both air inlet ducts and outlet ducts.

Claims

1. An apparatus, comprising:

a housing defining a refrigerated storage space;

an air outlet configured to produce an air curtain that separates air in the refrigerated storage space from air exterior to the housing;

a cooling heat exchanger and which recovers air in the air curtain via an air inlet such that air can be recirculated to the air outlet;

a shelf disposed within the refrigerated storage space; and

a duct fluidically coupling the air inlet and the air outlet,

at least a portion of the duct and, at least a portion of the shelf defining at least a portion of a cavity beneath the shelf that is sealed from air recovered via the air inlet.

2. The apparatus of claim 1, wherein:

the air outlet is from one or more air outlets, the air inlet is from one or more air inlets, and the duct is from a one or more ducts, the apparatus further comprising:

one or more fans, each fan from the one or more fans configured to blow air towards an air outlet from the one or more air outlets,

the apparatus includes an equal number of ducts from the plurality of ducts and fans from the plurality of fans,

each duct from the one or more ducts fluidically couples an air inlet from the one or more air inlets to one fan from the one or more fans.

3. The apparatus of claim 1, wherein the cavity is evacuated.

4. The apparatus of claim 1, wherein the duct is an air inlet duct, the apparatus further comprising:

a fan configured to blow air towards the air outlet; and

an outlet duct disposed between the fan and the cooling heat exchanger such that air blown by the fan is directed towards the cooling heat exchanger.

5. The apparatus of claim 4, wherein the cavity is defined at least in part by a portion of the outlet duct.

6. The display refrigerator or freezer of claim 1, wherein the cavity is defined at least in part by insulation material.

7.-8. (canceled)

9. An apparatus, comprising:

a housing defining a refrigerated storage space;

a cooling heat exchanger;

a fan configured to blow air towards an air outlet via the cooling heat exchanger to form an air curtain that separates the refrigerated storage space from air exterior to the housing, the cooling heat exchanger configured to recover air in the air curtain via an air inlet for recirculation to the air outlet; and

a duct arranged between the fan and the cooling heat exchanger such that air blown by the fan is directed towards the cooling heat exchanger.

10. The apparatus of claim 9, wherein:

the duct is from one or more ducts and the fan is from one or more fans;

the apparatus includes the same number of ducts and fans; and

each duct from the one or more ducts is arranged to direct air to one fan from the one or more fans.

11. A method of modifying a display refrigerator or freezer, wherein the display refrigerator or freezer includes a refrigerated storage space, air in the refrigerated storage space being separated from air exterior to the display refrigerator or freezer by an air curtain established by one or more fans which blow air towards one or more air outlets via a cooling heat exchanger, the cooling heat exchanger configured to recover air in the air curtain via one or more air inlets for recirculation to the one or more air outlets, the refrigerated storage space having a base shelf, the method comprising:

arranging one or more air inlet ducts between the one or more air inlets and the one or more fans such that the air recovered via the one or more air inlets is directed by the one or more air inlet ducts towards the one or more fans such that the one or more air inlet ducts, in combination with at least a portion of the base shelf, define at least a portion of a cavity beneath the base shelf, the cavity being sealed from the air recovered via the one or more air inlets.

12. The method of claim 11, further comprising arranging the same number of air inlet ducts between the air inlets and the fans as the number of fans such that each air inlet duct from the one or more air inlet ducts is configured to direct air to one fan from the one or more fans.

13. The method of claim 11, further comprising evacuating the cavity.

14. The method of claim 11, further comprising arranging one or more outlet ducts between the one or more fans and the cooling heat exchanger such that air blown by the one or more fans is directed towards the cooling heat exchanger.

15. The method of claim 14, further comprising arranging the one or more outlet ducts such that the cavity is defined at least in part by a portion of the one or more outlet ducts.

16.-19. (canceled)