CN112797693A

CN112797693A - Refrigerated display case with air flow guide

Info

Publication number: CN112797693A
Application number: CN202011269024.9A
Authority: CN
Inventors: C·瓦莱; R·K·迪格特
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 2019-11-14
Filing date: 2020-11-13
Publication date: 2021-05-14
Also published as: EP3821768B1; ES2971797T3; EP3821768A1; FI3821768T3

Abstract

A refrigerated display case includes a storage space and an air flow directing system for supplying refrigerated air to the storage space. The air flow guiding system includes: an inlet air passage extending in a horizontal direction from a front face of the refrigeration showcase toward a rear face of the refrigeration showcase; a corner where the air flow exits the inlet air passage and turns toward a vertical direction so as to bypass an inner surface of the corner; a low pressure space located behind the corner; a pressure boundary wall separating the low pressure space from the high pressure space; at least one outlet for directing a flow of air from the plenum to cool the storage space; and a fan for generating a pressure differential between the low pressure space and the high pressure space to thereby draw air through the inlet air passage and around the corner before driving the air outwardly from the at least one outlet. The corner includes a curved or chamfered portion on the inner surface that extends between an upper boundary of the inlet air passage and an interior surface of the low pressure space.

Description

Refrigerated display case with air flow guide

Technical Field

The present invention relates to a refrigerated display case including an air flow directing system and to a method for manufacturing a refrigerated display case using an air flow directing system.

Background

Refrigerated display cases, such as those used in retail environments, provide a refrigerated display space for refrigerated goods, such as perishable goods or goods that consumers prefer refrigerated merchandising conditions. Refrigerated display cases maintain the product below ambient temperature by using cooled air that is circulated around the product. Typically, refrigerated display cases will include a storage space having a number of horizontal shelves and an opening at the front side of the shelves. The opening allows a consumer and/or retail personnel to access the shelf and the items located on the shelf from the front of the storage space. In some cases, the opening may be covered by a door or curtain. An air curtain may be used, for example, a flow of cooled air and/or a flow of ambient air across an opening. Cooling for a refrigerated display case is provided by heat exchange with a heat absorbing heat exchanger of the chiller. This can be a cooler integrated with the display case, such as a refrigeration unit, wherein the evaporator of the refrigeration unit is a heat absorption heat exchanger. In some cases, a refrigeration system at a remote location may be linked to heat absorption heat exchangers at multiple refrigeration display cases via a heat exchange circuit.

A typical refrigerated display case such as that shown in figure 1 and disclosed in WO 2013/029686 includes the following fans: the fan is used to circulate air to provide cooled air to the storage space and hence to the refrigerated goods. The fan is provided with air via an inlet, wherein the inlet is typically supplied with incoming air flowing via a passage extending in a horizontal direction below the storage space. The incoming air can come from within the storage space and/or from outside the refrigerated display case. The incoming air flow is diverted from the horizontal toward the vertical, then flows through the fan and flows upward at the back of the storage space behind the vertical rails that provide support for the shelves. An exemplary arrangement can be seen in fig. 1.

Disclosure of Invention

Viewed from a first aspect, the present invention provides a refrigerated display case comprising a storage space and an air flow directing system for supplying refrigerated air to the storage space, the air flow directing system comprising: an inlet air passage extending in a horizontal direction from a front face of the refrigeration showcase toward a rear face of the refrigeration showcase; a corner where the air flow exits the inlet air passage and turns toward the vertical, thereby bypassing an inner surface of the corner; a low pressure space located behind the corner; a pressure boundary wall separating the low pressure space from the high pressure space; at least one outlet for directing a flow of air from the plenum to cool the storage space; and a fan for generating a pressure differential between the low pressure space and the high pressure space to thereby draw air through the inlet air passage and around the corner before driving the air outwardly from the at least one outlet; wherein the corner comprises a curved or chamfered portion on the inner surface, the curved or chamfered portion extending between an upper boundary of the inlet air passage and an interior surface of the low pressure space, wherein the curved or chamfered portion of the inner surface extends at least 10 mm in both the vertical and horizontal directions.

With this arrangement, sharp corners are avoided at the inner surface, and, as a result, the air flow does not bypass abrupt changes in direction at the position where the air flow flows in contact with the inner surface. In the past, simple 90 ° bends have been used, for example as shown in WO 2013/029686. Surprisingly, the inventors have found that by limiting the escape of the air flow from the inner surface that occurs at this point through the use of a chamfer or bend as described hereinabove, then, particularly where the fan circulates air at a higher flow rate, there is a significant reduction in noise from the air flow directing system. This allows quieter operation and/or allows the use of improved fans without the negative effects of increased noise. That is, all else being equal, then the proposed curved or chamfered surface will reduce the noise generated during use of the refrigerated display case as compared to using a 90 ° bend instead of a chamfered/curved portion (as in the prior art disclosure of WO 2013/029686).

It will be appreciated that the refrigerated display case is oriented with the top and base in use, and, therefore, as used herein, references to horizontal and vertical should be understood with reference to this orientation. Refrigerated display cases have a vertical extent between the top and base thereof and a horizontal extent between the front and back (depth of the case) and between the sides (width of the case). The storage space may be accessible from the front of the refrigerated display case, or alternatively may be accessible from elsewhere (such as from above). The inlet air passage extends in a horizontal direction (i.e. a direction that spans a distance in the horizontal direction but need not be exactly horizontal). The horizontal extent of the inlet air passage in the direction of the airflow extends from the front towards the back of the cabinet and may terminate at the low pressure space. The inlet air passage also has a horizontal extent transverse to the direction of airflow, and this may be at least the width of the fan, optionally larger than the fan, and may span a substantial portion of the width of the cabinet. The corner may have a horizontal extent transverse to the direction of airflow that is at least the width of the fan, optionally larger than the fan, and may span a majority of the width of the cabinet. In an exemplary embodiment, the corner has a width that is at least as large as the width of the inlet air passage. The air flow directing system of the first aspect offers additional advantages when the corner and inlet air passages are relatively wide, and this type of refrigerated display case will be distinguished from refrigerated display cases that use relatively narrow passages, such as passages that funnel air through a flow path that occupies only a small portion of the width of the case in its narrowest point and that may be narrower than the width of the fan. Indeed, as discussed further below, the inlet air passage and other portions (particularly corners) of the airflow guide may provide a flow path for air traveling toward the plurality of fans such that the width of the inlet air passage and the width of the corners extend across the width of the cabinet including the plurality of fans.

The low pressure space may be toward the rear of the refrigerated display case, as compared to the location of the fan, or the low pressure space may be toward the front of the case, as compared to the location of the fan, with the high pressure space being the other side of the fan. The corner may be located on an interior surface extending between an upper boundary of the inlet air passage and an interior surface of the low-pressure space facing the front of the refrigerated display case. The inner surface may be a substantially vertical surface.

In the example where the low pressure space is towards the front of the cabinet, then, the interior surface may be located at a point between the low pressure space and the storage space. In this case, the fan and the pressure boundary wall may be positioned across an open area of the low-pressure space opposite the interior surface joining the corner.

Alternatively, where the low pressure space is towards the rear of the cabinet compared to the fan, then the interior surface may be a surface of the pressure boundary wall, i.e. a surface of the wall located between the low pressure space and the high pressure space. The pressure boundary wall may have a vertical extent, and, in some examples, the pressure boundary wall may be substantially vertical. Thus, the corner may be located at a directional turn of the air flow from the horizontal extent of the inlet air passage to the vertical extent of the pressure boundary wall, which in some examples will be a turn from substantially horizontal to substantially vertical through a right angle.

The corner has an inner surface as follows: the inner surface is a surface located at an inner side of the corner and may face an outer surface located at an outer side of the corner, wherein the inner and outer surfaces form a boundary for an air flow around the corner. The surface extends from an upper boundary of the inlet air passage, which may be a wall separating the inlet air passage from a refrigerated space located above the inlet air passage. The inner surface extends to an inner surface of the low pressure space, which may be a rearward surface of the substantially vertical wall. The wall may be constructed as a single layer or multiple layers, such as where there is insulation between the outer layers.

The inner surface may be curved or chamfered and, in a vertical cross-section viewed from the side of the refrigerated display case, the inner surface is cut or truncated compared to the straight extension of the upper boundary of the inlet air passage and the straight extension of the interior surface of the low pressure space. The upper boundary of the inlet air passage and the inner surface of the low-pressure space may for example constitute a right angle to each other, so that if the upper boundary of the inlet air passage and the inner surface of the low-pressure space extend without a bend or chamfer, the upper boundary of the inlet air passage and the inner surface of the low-pressure space will form an approximately 90 ° bend. The bend or chamfer cuts off the 90 ° bend in the vertical and horizontal directions over a range of at least 10 mm. Thus, for example, the curved portion may be a quarter circle of radius 10 mm or some other circular arc having a larger radius spanning a chord length of at least about 14 mm. Alternatively, the chamfered portion may truncate the inner surface across a length of at least about 14 mm, such as wherein a 45 ° chamfer (i.e., two corners having an outer angle of 135 °) provides a diagonal in the range of at least 10 mm in the vertical and horizontal directions. Thus, the bend or chamfer may span a length of at least 14 mm in a diagonal line extending tangential to the direction of air flow around the corner. The vertical extent and/or horizontal extent of the bend or chamfer may be greater than 10 mm, such as at least 15 mm or at least 20 mm, in one or both of the vertical and horizontal directions. More than one chamfer may be used, thus providing multiple straight sections around the inner surface of the corner. The inner corner may also include a combination of curved surfaces and edges or flat surfaces.

The vertical extent of the inlet air passage may be at least 40 mm, such as at least 60 mm or at least 80 mm. The vertical extent and horizontal extent of the bend or chamfer may be at least 10%, optionally at least 15%, of the vertical extent of the inlet air passage. These dimensions will provide sufficient air volume for the refrigeration of a typical refrigerated space.

The fan may be located above the corner within the pressure boundary wall. Thus, the fan may be accommodated in an opening through the pressure boundary wall. In the case of a substantially vertical wall, the fan (in the case of a fan with axial flow) is therefore fitted with substantially vertically arranged fan blades and a substantially horizontal axis of rotation for the fan blades. A typical fan may have a diameter of at least 200 mm (e.g., about 250 mm). In some examples, the fan includes blades having both radial and axial elements, i.e., the fan may be of a mixed flow type, such as an axial fan having radial components. For example, a fan blade may have a tip rail. Optionally, the fan orifice includes an inflow straightener. It has been found that there are particular benefits to noise reduction when the proposed curved or chamfered corners are used with such fans. There may be a plurality of fans, e.g., 3, 4, 5 or more fans, spaced across the width of the refrigerated display case between its sides. The width of the corner may span the position of more than one fan (preferably all fans). Thus, the air flow directing system may deliver air to a plurality of fans. The air inlet passage and the corner may provide an air flow to the plurality of fans, wherein each of the plurality of fans draws air from the same space. Advantageously, with this arrangement, if one fan fails, the full width of the air inlet passageway can still be utilized to draw air into the low pressure space, as the low pressure space can be common to all fans, and/or as other (non-failing) fans can draw air from the common air inlet passageway. Optionally, the inlet air passage is common to all fans and there is a single low pressure space and a single high pressure space, both common to all fans.

The fan(s) drive an air stream through the outlet into the storage space of the refrigerated display case. This allows cooling, as the air may also pass through a heat absorbing heat exchanger for cooling the air, which may be placed before the fan(s) or after the fan(s), as discussed below. In some examples, the fan(s) also drive an air flow through an air curtain system in which uncooled air provides an air curtain in front of the refrigerated display case to help retain cooled air within the storage space. Thus, the fan(s) may provide increased air pressure to the plenum, which may then direct the air flow partially through the heat absorbing heat exchanger for cooling the air, and then to the outlet to enter the storage space, and may direct the air flow partially around the heat absorbing heat exchanger and through the air curtain air flow path. Thus, the plenum may provide air flow for both the cooled air and the air curtain that is not being cooled.

The refrigerated display case can include a leg portion disposed within the inlet air passage. Such leg portions can be present to support at least a portion of the weight of components of the refrigerated display case that are placed above the inlet air passage. For example, the leg portions may support at least a portion of the weight of the pressure boundary wall and/or the fan. Alternatively or additionally, the foot portion may support at least a proportion of the weight of the shelves and, where present, the items within the refrigerated space, such as by supporting vertical rails that hold the shelves and, where present, the items. In some examples, there are a plurality of leg portions spaced along the width of the refrigerated display case between its sides, i.e., along the width of the opening of the portion forming the inlet air passage.

The foot portion(s) may span the vertical extent of the inlet air passage as well as a portion of its width. Thus, the foot portion(s) can transfer vertical loads from above the inlet air passage to its base, which can be the base of a refrigerated display case.

In an exemplary embodiment, the foot part(s) is/are arranged for through-flow of air. Thus, the foot portion may have one or more internal passages for air arranged to receive air from an upstream location in the air flow path and discharge air to a downstream location in the air flow path. The downstream location may be a low pressure space. The internal passageway of the foot portion(s) may be a plurality of parallel passageways.

The refrigerated display case can include at least one leg portion located below or adjacent to the fan, wherein the at least one leg portion below the fan also optionally supports a vertical track for supporting a shelf of the refrigerated space.

A refrigerated display case can include a heat absorbing heat exchanger for cooling the air. For example, the heat absorbing heat exchanger may be placed before the fan or after the fan. In one possible embodiment, the warm return air passes along the inlet air passageway into the low pressure space, through the fan, and then through the heat absorbing heat exchanger. In this case, at least a portion of the air from the high pressure space may be directed through the heat absorption heat exchanger before being directed into the refrigerated space for cooling the refrigerated goods therein. Optionally, different portions of the air from the plenum may bypass the heat absorption heat exchanger to provide an uncooled air stream to an air curtain positioned in front of the refrigerated display case.

The heat absorbing heat exchanger can be an evaporator of a refrigeration circuit, wherein the refrigeration circuit is optionally incorporated into a refrigerated display case.

Viewed from a second aspect, the present invention provides a method for manufacturing a refrigerated display case having an air flow directing system as hereinbefore described with respect to the first aspect. Thus, the manufacturing method may comprise: providing a refrigerated display case including a storage space accessible from a front of the refrigerated display case and an air flow directing system for supplying refrigerated air to the storage space; forming an air flow guiding system having: an inlet air passage extending in a horizontal direction from a front face of the refrigeration showcase toward a rear face of the refrigeration showcase; a corner where the air flow exits the inlet air passage and turns towards the vertical; a low pressure space located behind the corner; a pressure boundary wall separating the low pressure space from the high pressure space; and at least one outlet for directing a flow of air from the plenum to cool the storage space; providing a fan for generating a pressure differential between the low pressure space and the high pressure space to thereby draw air through the inlet air passage and around the corner prior to driving the air outwardly from the at least one outlet; and, the method includes forming the corner with a curved or chamfered portion on the inner surface, the curved or chamfered portion extending between an upper boundary of the inlet air passage and an interior surface of the low pressure space, wherein the curved or chamfered portion of the inner surface extends at least 10 mm in both the vertical and horizontal directions.

The air flow directing system may be provided with any other features as discussed above.

Drawings

Certain preferred embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which:

FIG. 1 shows a cross-section for a known refrigerated display case;

FIG. 2 is a front elevational view of the internal layout of the fan for a known refrigerated display case;

FIG. 3A is a close-up cross-section of a rear corner of the proposed refrigerated display case showing details of the air flow path;

FIG. 3B shows an alternative arrangement for the air flow path at the rear corner;

FIG. 4 is a front view of an exemplary internal layout for a fan of the proposed refrigerated display case;

figure 5 illustrates another exemplary internal layout for the fan of the proposed refrigerated display case;

FIG. 6 is a perspective view of an air flow foot portion that may be used within the air flow path of FIG. 3A or FIG. 3B; and

FIG. 7 is a perspective view of an alternative design for an air flow foot portion that may be used within the air flow path of FIG. 3A or FIG. 3B.

Detailed Description

In fig. 1, a known refrigerated display case 2 as discussed in WO 2013/029686 is shown in a schematic side view with the side walls/covers removed in order to give a good view into the refrigerated space 10 (also described as the product display space 10). It will be appreciated that while the refrigerated display case 2 of fig. 1 is of known design, the features of the case can be usefully modified with the air flow paths, fans and/or air through flow leg portions described hereinafter with reference to fig. 3A to 7. Thus, examples utilizing the features described in connection with fig. 3A-7 may include the airflow features described herein with respect to fig. 1. The refrigerated display case 2 is of the front access type and may also be referred to as a refrigerated sales cabinet. The refrigerated display case 2 allows substantially horizontal access to the merchandise displayed in the refrigerated display case 2 by a customer standing in front of (to the right in fig. 1) the refrigerated display case 2.

Depending on the type of refrigerated commodity, the refrigerated display case described herein can operate at normal cooling temperatures above 0 ℃ or at chilled temperatures below 0 ℃.

Although the refrigerated display case 2 of fig. 1 is open at its front access side, the refrigerated display case 2 can also be equipped with a sliding or pivoting door at its front access side which must be opened to provide access to the product display space 10. Alternatively, the front proximal side may be shielded by a screen or shade. The refrigerated display case of fig. 1 includes: a horizontal base 4, which may be provided with a bracket (not shown); an upright display case rear wall 6 extending from the rear end of the base 4, the display case rear wall 6 typically being positioned in front of a building wall or back-to-back with other retail displays (such as another similar display case 2); and a roof 8 extending over the refrigerated space 10. The base 4, display case rear wall 6, and top 8, along with side walls (not shown), enclose an interior space of the refrigerated display case 2, which includes a refrigerated space 10 as a major portion thereof. The refrigerated space 10 is a goods presentation space 10 defined by a goods presentation space bottom wall 14, a perforated goods presentation space rear wall 16 and an upper goods presentation space wall 19.

The refrigerated display case 2 also includes

air passages

20, 32, 48, 60, a fan 30 and an evaporator 46 located at least partially outside the product display space 10. The

air channels

20, 32, 48, 60, the fan 30 and the evaporator 46 are arranged between the display case rear wall 6 and the perforated goods presentation space rear wall 16, part of the air suction channel 20 is arranged between the base 4 and the goods presentation space bottom wall 14, and the substantially horizontal channel portion 52 of the cold air channel 48 and the substantially horizontal channel portion 64 of the warm air channel 60 extend between the upper goods presentation space wall and the top 8.

In this example, there are three

merchandise display shelves

70, 72, the

merchandise display shelves

70, 72 being securable by suitable means to the merchandise display space side walls (not shown) and the perforated merchandise display space rear wall 16, the

merchandise display shelves

70, 72 extending substantially horizontally and carrying merchandise to be displayed and sold. Although three

merchandise display shelves

70, 72 are shown in FIG. 1, any suitable number of merchandise display shelves may be provided within the merchandise display space 10.

Optionally, the refrigerated display case 2 can include a product compartment located below the lowermost portion of the

product display shelves

70, 72. In this case, the lowermost of the three goods presentation shelves 70 is formed as an air guide goods presentation shelf 72. Cold air from the cold air channel 48 (described below) may flow into the interior of the air guide shelves 72 as shown and be directed in a generally vertical direction and downwardly through appropriate openings at the underside of such shelves 72 to the product compartments located beneath the air guide shelves 72. In fig. 1, the product compartment is located in the bottom region/base compartment 12 of the refrigerated display case 2. By using this type of air-directing merchandise display shelf 72, efficient cooling of merchandise located in the under-floor compartment may be achieved. In other variations, the front open refrigerated space 10 may extend within the refrigerated display case at the lower portion, and in that case, the merchandise display shelves may include one or more additional shelves facing downwardly at the lower portion in place of the merchandise compartments. A removable buffer 76 can be placed at the lower front portion of the refrigerated display case 2.

Between the front end of the goods presentation space bottom wall 14 and the lower front portion of the refrigerated display case 2, there is an air inlet opening 22 of the air suction channel 20, the air inlet opening 22 forming an inlet air passage 20 into which relatively warm return air enters 20. The return air is conveyed through a substantially horizontal air intake channel portion 24 arranged between the base 4 and the goods presentation space bottom wall 14 and through a substantially vertical rear air intake channel portion 26. The rear air intake channel portion 26 is a low pressure space 26 that is disposed at a location behind the bottom region 12 of the product display space 10 and is disposed adjacent to and substantially parallel to the display case rear wall 6. Return air enters this low-pressure space 26, which is at a reduced air pressure due to the fan 30, the fan 30 sucks in relatively warm return air through such an air suction channel 20 and pushes the relatively warm return air through the air pressure channel 32, whereby the air pressure channel 32 forms a high-pressure space 32, in which high-pressure space 32 the air pressure is higher than the air pressure of the low-pressure space 26 during operation of the fan 30.

Air is transferred from the high pressure space 32 through the heat absorbing heat exchanger 46 (e.g., evaporator 46), through the cold air channel 48 and through the perforated goods presentation space rear wall 16 to the goods presentation space 10. It will be appreciated that the placement of the heat absorbing heat exchanger 46 after the fan 30 may be switched with alternative arrangements as follows: wherein the heat absorbing heat exchanger 46 exchanges heat with air in front of the fan 30, such as within the horizontal air intake passage portion 24.

The bottom part 34 of the high-pressure space 32 extends at the end of the air intake channel 20 in front of the low-pressure space 26 and extends substantially parallel to the low-pressure space 26. The low-pressure space 26 is separated from the bottom portion 34 of the high-pressure space 32 by the vertical wall 28, and therefore the vertical wall 28 is the pressure boundary wall 28. While the wall is described herein as vertical, it will be appreciated that the wall need not be vertical, and, in variations of the depicted embodiment, the wall may be other than vertical, while achieving the same basic effect of separating the low and high pressure regions and supporting the fan 30. The fan 30 is arranged in a suitable opening of the vertical wall 28, and, in addition to this opening, the wall 28 may be sealed to prevent air from moving between the high-pressure space 32 and the low-pressure space 26. The plenum 32 also has an upper portion 36, the upper portion 36 having a greater width than the bottom portion 34, the upper portion 36 extending between the display case rear wall 4 and the cool air duct 48. It will be appreciated that it is possible to have several fans 30 across the width of the refrigerated display case 2, for example, as shown in figure 2.

The cool air duct 48 spans the height of the refrigerated display case 2 at the rear of the refrigerated space 10. Above the fan 30 and the heat absorbing heat exchanger 46 (if present), a cool air duct 48 distributes air to the refrigerated space 10 through suitable openings in the perforated goods presentation space rear wall 16 and allows the air to move to the top 8 and base of the refrigerated display case 2. Towards the base and near the height of the fan 30, a second vertical wall 42 separates the plenum 32 from the bottom portion of the cool air passage 48.

To provide the air curtain, the warm air channel 60 allows air from the plenum 32 to bypass the heat absorption heat exchanger 46 and flow through the vertical warm air channel portion 62 at the rear of the cabinet 2. The warm air channels 60 extend along the display case rear wall 6 and top 8 to warm air curtain openings 66. the warm air curtain openings 66 can be honeycomb openings that are positioned at the front of the top 8. In parallel with the top warm air channel portion 64, the generally horizontal cool air channel portion 52 delivers cool air from the cool air channels 48 to the front of the roof 8, where there is a cool air curtain opening 56 as described hereinafter, at the front of the roof 8. A portion of the air stream flowing through the warm air channel 60 is not cooled by the heat absorbing heat exchanger 46. Such warm air exits the warm air channel 60 through the warm air openings 66 and forms a warm air curtain 68 at the front of the goods presentation space 10, the warm air curtain 68 extending between the warm air curtain openings 66 and the air intake opening 22 of the air intake channel 20.

Part of the air flow flowing through the heat absorption heat exchanger 46 is cooled in the heat absorption heat exchanger 46, for example, via heat exchange with refrigerant circulating in a refrigeration cycle. The air exiting the heat absorption heat exchanger 46 from the upper outlet side of the heat absorption heat exchanger 46 is referred to as cold discharge air and exits the cold air passage 48 as a stream of chilled air supplied from the cold air passage 48 to the goods presentation space 10 from the rear through the perforated goods presentation space rear wall 16 and as a stream of cold air curtains supplied to the air curtain openings 56 adjacent the warm air curtain openings 66 and positioned at the front of the roof 8 directly behind the warm air curtain openings 66 so as to form a cold air curtain 58, the cold air curtain 58 flowing from the cold air curtain openings 56 along the front side of the goods presentation space 10 to the air intake opening 22 of the air intake passage 20. The curtain of refrigerated air 58 is formed rearwardly of the curtain of warm air 68, which has been found to be particularly effective in reducing the amount of warm air entering the product display space 10 from the front.

As noted above, the heat absorption heat exchanger 46 may be an evaporator 46, which evaporator 46 in turn may be part of a refrigeration circuit (not shown) comprising at least a compressor, a condenser, an expansion device, the evaporator 46 and refrigerant conduits connecting these elements in series so as to form a closed refrigeration cycle.

The refrigerated display case 2 can include a plurality of fans 30 spaced across the width of the display case 2. A possible arrangement is shown in fig. 2, in which the front portion of the enclosure, including the

shelves

70, 72, the rear wall 16 of the refrigerated space 10 and the rear air passage, is removed so that it can be seen that the fan 30 is mounted within the generally vertical wall 28 separating the low-pressure space 26 and the high-pressure space 32. The low pressure space 26 is enclosed within a vertical rear wall 28 and a horizontal upper enclosure portion that spans between the vertical rear wall 28 and the display case rear wall 6. The plenum 32 is located just in front of the fan 30 and the air passage 48 will extend up the height of the rear wall 6 of the display case. The inlet air passage 20 extends along the base 4 and, when the refrigerated display case 2 is fully assembled, the inlet air passage 20 will be enclosed on its upper side by the bottom wall 14 of the refrigerated space 10.

In this example, there are six fans 30 spaced across the width of the refrigerated display case 2, and the width of the refrigerated display case 2 can be, for example, 3.75 m. The fan 30 is connected to the common low-pressure space 26 and the high-pressure space 32. Each fan 30 is located below a condensate shield 78 (i.e., a horizontally projecting element for shielding the fan 30 from any condensate droplets that may form in the air passageway located above). Also visible in fig. 2 are foot portions 80 spaced along an opening at the base of the vertical wall 28. The opening at the base of the vertical wall 28 forms part of the inlet air passage 20. The leg portions 80 span the opening and, thus, the vertical extent of the inlet air passage 20 to provide support for the portion of the refrigerated display case 2 above the opening, including the vertical wall 28 (with the fan 30 retained therein) and the rear wall 16 of the refrigerated space 10. It will be appreciated that this rear wall 16 provides support for

shelves

70, 72, such as via vertical rails 84 of the type described below with reference to fig. 4, in fig. 2 the vertical rails 84 may be aligned with vertical indicia 82 on the display case rear wall 6. Thus, in some examples, the foot portion 80 will directly carry a portion of the weight of the racks 70, 72 (and the items thereon) via one of the vertical rails 84.

Advantageously, the design for the refrigerated display case 2 of fig. 1 is modified as shown in fig. 3A or 3B. This figure shows an enlarged view of the rear corner of the refrigerated display case 2, which includes portions of the display case rear wall 6 and base 4. As with the arrangement of fig. 1, the low-pressure space 26 and the high-pressure space 32 are separated from each other by a vertical wall 28, but in this case the wall holds a fan 130, the fan 130 using both axial flow elements and radial flow elements (such as by including a tip rail) in order to improve the performance of the fan 130. In fig. 3A, the fan 130 is in the same orientation as in fig. 1. In fig. 3B, as discussed in more detail below, the fan 130 is in an opposite orientation such that the low-pressure space 26 and the high-pressure space 32 switch positions. The arrangement of refrigerated space 10 and air passageways at portions of the refrigerated display case 2 (which are not shown in fig. 3A and 3B) can be similar to that in fig. 1, such as via the use of partial warm/cold streams and air curtains. The refrigerated display case 2 of fig. 3A or 3B can include a heat absorption heat exchanger 46 similarly positioned to the evaporator 46 of fig. 1, or the refrigerated display case 2 can cool air by some other positioning of the heat absorption heat exchanger.

Considering the arrangement of fig. 3A in more detail, the airflow directing system in fig. 3A differs in a significant way with respect to the arrangement of fig. 1 with respect to the connection between the inlet air passage 20 and the low pressure space 26. In particular, it can be seen that in fig. 1, consistent with the disclosure of WO 2013/029686, there is a right angle corner 100 between the upper wall of the inlet air passage 20 and the vertical wall 28 enclosing the low pressure space 26. In contrast, in the example illustrated in fig. 3A, there is a corner 88, the corner 88 including a chamfered portion 90 on an inner surface, the chamfered portion 90 extending between an upper boundary 92 of the inlet air passage 20 and the low pressure facing surface of the wall 28. The chamfered portion 90 may alternatively be replaced by a curved portion. The curved or chamfered portions at the corners 88 extend in both the vertical and horizontal directions in order to minimize flow separation at the corners 88. In this example, the chamfer has two 135 ° edges instead of the single 90 ° edge of fig. 1, and the vertical and horizontal extent of the chamfer is about 25 mm. By adapting the form of the inner surface and avoiding the 90 ° edge of fig. 1, separation of the air flow is then avoided, and this has been found to contribute to noise reduction, especially in the context of using a fan 130 having axial and radial blade elements.

For example, the fan 130 may be a fan having a tip rail located on the fan blades, such as the fan disclosed in US 2019/234419. As noted above, when combined with improvements to the design for the fan 130, the benefits from the modification to the air flow path confer particular advantages as the benefits of noise reduction increase.

Turning now to FIG. 3B, a similar modification is shown for the flow path, in the following cases: wherein the direction of air flow through the fan 130 is toward the rear of the refrigerated display case 2, rather than toward the front of the refrigerated display case 2. As a result, the low-pressure space 26 moves toward the front of the cabinet 2 so as to be located immediately adjacent the rear wall 16 of the refrigerated storage space 10, and the high-pressure space 32 is the other side of the pressure boundary wall 28 so as to be located immediately adjacent the outer rear wall 6 of the refrigerated display case 2. With this alternative arrangement, the corner 88 is located on an interior surface extending between the upper boundary 92 of the inlet air passage 20 and an interior surface of the low pressure space, which is a surface of the rear wall 16 of the refrigerated storage space 10. The air flows back to the plenum by the fan 130 and then flows upward toward a flow path similar to that shown in fig. 1, such as via the heat exchanger 46 and/or into a separate flow path for the air curtain arrangement.

An additional feature of the exemplary embodiment of fig. 3A and 3B is that the internal layout and number of fans 130 can be adjusted compared to the situation shown in fig. 2, wherein with the use of a modified fan 130, the pitch is likely to be increased, since fewer fans 130 can provide the same air flow. The result can be an arrangement as shown in fig. 4 with fewer fans 130 for the same width than the arrangement shown in fig. 5, both fig. 4 and 5 depicting a refrigerated display case 2 having a width of 2.5 mm. As with fig. 2, fig. 4 and 5 show interior views of the rear portion of the refrigerated display case 2 at a lower portion thereof, with the front portion of the enclosure including the

shelves

70, 72, the rear wall 16 of the refrigerated space 10 and the rear air passageway removed so that the fan 130 can be seen mounted within the generally vertical wall 28 separating the low pressure space 26 and the high pressure space 32. The inlet air passage 20 extends along the base 4 and, when the refrigerated display case 2 is fully assembled, the inlet air passage 20 will be enclosed on its upper side by the bottom wall 14 of the refrigerated space 10. In fig. 4, there are three fans 130 spaced across the 2.5 m width of the refrigerated display case 2, and so there is a reduced number of fans 130 compared to fig. 5 which uses four fans 130. This can result in cost savings.

Fig. 4 and 5 also illustrate a foot portion 80, the foot portion 80 being used in a similar manner as the foot portion 80 in fig. 2 to provide support to the vertical wall 28 holding the fan 130 and to support at least a portion of the weight from the

racks

70, 72 via one or more rack support rails 84 illustrated in fig. 4. The example of fig. 5 may likewise include a track 84 supported by the central leg portion 80. It will be noted that the condensate guard 78 is not present in fig. 4 and 5. This is possible because the fan 130 includes a fan orifice 79 that extends forward of the pressure boundary wall 28. The upper portion of the fan aperture 79 acts as a condensate guard, meaning that the separate condensate guard 78 may be omitted.

Further variation of the air flow may be provided by using a leg portion 80 that allows through-flow of air, for example as shown in fig. 6 or 7. Referring to fig. 3A, 3B, 4 and 5 and the discussion above, the foot portion 80 is seated within an opening at the base of the vertical wall 28 separating the low pressure space 26 and the high pressure space 32. The leg portion 80 extends across the height of the inlet air passage 20. It will be seen that the foot portion 80 only covers a small portion of the opening for air to enter the low pressure space 26. However, the leg portion 80 will still have an effect on the air flow. In the past, leg portions 80 have been used that have enclosed walls that block the airflow and divert the airflow around the leg portion 80. This obstructs the air flow and increases turbulence, thereby potentially increasing noise from the refrigerated display case 2. The improvement is provided when air can flow through the foot portion 80. It will be appreciated that these improvements are particularly significant where the foot portion 80 is close to the fan 130, particularly when the foot portion 80 is located directly below the fan 130 as is the central foot portion 80 in fig. 4.

Referring to fig. 6 and 7, the proposed flow-through foot portion 80 includes a flow-through passage between an inlet 94 at an upstream end of the foot portion 80 and an outlet 96 at a downstream end of the foot portion 80. When installed in the refrigerated display case 2, the inlet 94 faces the incoming air in the inlet air passage 20, and the outlet 96 discharges air into the low pressure space 26. The outlet 96 has an opening that faces both vertically and horizontally. The leg portion 80 includes an upper load bearing surface 98, which upper load bearing surface 98 is advantageously flat and can receive the weight of various portions of the refrigerated display case 2 above the leg portion 80. To transfer the load from the upper load bearing surface 98 to the bottom of the foot portion 80 (which sits on the base 4 of the refrigerated display case 2), the foot portion 80 includes a side wall 99.

Fig. 6 shows an example of a foot portion 80 that may be molded from plastic. The leg portion 80 includes an inner wall that increases strength and forms a boundary of a plurality of internal flow paths. The plurality of internal flow paths together form a through-flow passage between the inlet 94 and the outlet 96. Fig. 7 shows an alternative design that may be stamped or folded from sheet metal, wherein a fully open through-flow passage is located between the inlet 94 and the outlet 96.

Claims

1. A refrigerated display case including a storage space and an air flow directing system for supplying refrigerated air to the storage space, the air flow directing system comprising:

an inlet air passage extending in a horizontal direction from a front face of the refrigeration showcase toward a rear face of the refrigeration showcase;

a corner where the air flow exits the inlet air passage and turns toward a vertical direction, thereby bypassing an inner surface of the corner;

a low pressure space located behind the corner;

a pressure boundary wall separating the low pressure space from the high pressure space;

at least one outlet for directing the flow of air from the plenum to cool the storage space; and

a fan for generating a pressure differential between the low pressure space and the high pressure space to thereby draw air through the inlet air passage and around the corner prior to driving the air outwardly from the at least one outlet;

wherein the corner comprises a curved or chamfered portion on the inner surface extending between an upper boundary of the inlet air passage and an interior surface of the low pressure space, wherein the curved or chamfered portion of the inner surface extends at least 10 mm in both the vertical direction and the horizontal direction.

2. The refrigerated display case of claim 1 wherein the inner surface of the corner is cut or truncated as compared to the straight extension of the upper boundary of the inlet air passage and the straight extension of the interior surface of the low pressure space, wherein the cut or truncated portion extends across a length of at least about 14 mm.

3. A refrigerated display case according to claim 1 or 2 wherein the vertical extent and/or horizontal extent of the bend or chamfer is at least 15 mm in one or both of the vertical and horizontal directions.

4. A refrigerated display case as recited in claim 1, 2 or 3 wherein the width of the corner in a direction corresponding to the width of the refrigerated display case between its sides is greater than the fan diameter.

5. A refrigerated display case as claimed in any preceding claim wherein the fan is located within an opening through the pressure boundary wall above the corner.

6. A refrigerated display case according to any preceding claim comprising a plurality of fans spaced across the width of the refrigerated display case between its sides wherein the width of the corner spans more than one fan location.

7. A refrigerated display case as claimed in any preceding claim wherein the fan comprises blades having a tip rail and/or wherein the fan is of the mixed flow type.

8. A refrigerated display case as claimed in any preceding claim comprising at least one leg portion placed within the inlet air passage wherein the leg portion supports at least part of the weight of one or more components of the refrigerated display case placed above the inlet air passage.

9. A refrigerated display case as recited in claim 8 wherein the leg portions support at least a proportion of the weight of the shelves retained within the refrigerated space by supporting vertical rails of the shelves.

10. A refrigerated display case as claimed in claim 8 or 9 wherein the foot portion spans the vertical extent of the inlet air passage and part of its width and transfers vertical load from above the inlet air passage to its base.

11. A refrigerated display case according to claim 8, 9 or 10 wherein the leg portions are arranged for through flow of air and have one or more internal passageways arranged to receive air from an upstream location in the air flow path and discharge air to a downstream location in the air flow path.

12. A refrigerated display case according to any one of claims 8 to 11 comprising a plurality of leg portions wherein at least one leg portion is located below or adjacent a fan and supports a vertical rail for supporting shelves of the refrigerated space.

13. A refrigerated display case according to any preceding claim comprising a heat absorbing heat exchanger for cooling the air.

14. A method for manufacturing a refrigerated display case having an air flow directing system, the method comprising:

providing a refrigerated display case including a storage space and an air flow directing system for supplying refrigerated air to the storage space, forming the air flow directing system having:

an inlet air passage extending in a horizontal direction from a front face of the refrigeration showcase toward a rear face of the refrigeration showcase; a corner where the air flow exits the inlet air passage and turns toward a vertical direction, thereby bypassing an inner surface of the corner; a low pressure space located behind the corner; a pressure boundary wall separating the low pressure space from the high pressure space; and at least one outlet for directing the flow of air from the plenum to cool the storage space;

providing a fan for generating a pressure differential between the low pressure space and the high pressure space to thereby draw air through the inlet air passage and around the corner prior to driving the air outwardly from the at least one outlet; and

forming the corner with a curved or chamfered portion on the inner surface extending between an upper boundary of the inlet air passage and an interior surface of the low pressure space, wherein the curved or chamfered portion of the inner surface extends at least 10 mm in both the vertical direction and the horizontal direction.

15. A method as claimed in claim 14, including providing said refrigerated display case with features as claimed in any one of claims 2 to 13.