EP3821768B1

EP3821768B1 - Refrigerated display case with air flow guide

Info

Publication number: EP3821768B1
Application number: EP19209176.7A
Authority: EP
Inventors: Christophe Vallee; Ryan K Dygert
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2023-12-27
Anticipated expiration: 2039-11-14
Also published as: FI3821768T3; EP3821768A1; CN112797693A

Description

The present invention relates to a refrigerated display case comprising an air flow guide system, and to a method for manufacturing a refrigerated display case using the air flow guide system.
Refrigerated display cases as used in retail environments provide refrigerated display spaces for refrigerated goods, such as perishable goods or goods where a chilled sales condition is preferred by the consumer. The refrigerated display case keeps the goods below ambient temperature by the use of cooled air that is circulated around the goods. Typically a refrigerated display case will include a storage space with a number of horizontal shelves and an opening at a front side of the shelves. The opening permits a consumer and/or retail staff to access the shelves and the goods thereon from the front of the storage space. In some cases the opening can be shielded by a door or a curtain. An air curtain may be used, for example a flow of cooled and/or ambient air across the opening. Cooling for the refrigerated display case is provided by heat exchange with a heat absorbing heat exchanger of a cooler. This may be a cooler integrated with the display case, such as a refrigeration unit with an evaporator of the refrigeration unit being the heat absorbing heat exchanger. In some cases a refrigeration system at a remote location may link to heat absorbing heat exchangers at multiple refrigerated 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 a fan for circulating air in order to provide cooled air to the storage space and hence to the refrigerated goods. Air is provided to the fan via an inlet, with the inlet typically supplied by incoming air flowing via passages extending in a horizontal direction beneath the storage space. This incoming air can be from within the storage space and/or from outside of the refrigerated display case. The incoming air flow turns from the horizontal direction toward a vertical direction then flows through the fan and upward at the back of the storage space, behind vertical rails that provide support for the shelves. An example arrangement can be seen in Figure 1.
DE 14 01 509 A1 discloses a refrigerated display case in which a refrigerated airflow path circles an exterior of a refrigerated display area, and provides a refrigerated air curtain in front of the refrigerated display area. The airflow path comprises a lower section in which the airflow path is separated into two flow paths each comprising a fan and a heat absorbing heat exchanger. In one of the two flow paths the fan is disposed in a vertical passage behind the display area. US 2007/012059 A1 discloses a refrigerated display case in which a refrigerated air flow path circles an exterior of a refrigerated display area, and provides a refrigerated air curtain in front of the refrigerated display area. The refrigerated air flow path comprises a fan disposed in a horizontal passage beneath the display area.
Viewed from a first aspect, the present invention provides a refrigerated display case including a storage space and an air flow guide system for supplying refrigerated air to the storage space, the air flow guide system comprising: an inlet air passage extending in a horizontal direction from the front of the refrigerated display case toward a back of the refrigerated display case; a corner where the air flow exits the inlet air passage and turns toward a vertical direction passing around an inside surface of the corner; a low pressure space after the corner; a pressure boundary wall separating the low pressure space from a high pressure space; at least one outlet for directing the air flow from the high pressure space to cool the storage space; and a fan for generating a pressure difference 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 it out of the at least one outlet; wherein the corner includes a curved or chamfered portion on the inside surface extending between an upper boundary of the inlet air passage and an internal surface of the low pressure space, with the curved or chamfered portion of the inside surface extending at least 10 mm in both the vertical and horizontal directions, characterised by at least one foot part placed within the inlet air passage, wherein the foot part supports at least a portion of the weight of one or more components of the refrigerated display case that are placed above the inlet air passage.
With this arrangement, a sharp corner is avoided at the inside surface and consequently the air flow does not pass around an abrupt change in direction where it flows in contact with the inside surface. In the past a simple 90° bend has been used, as shown in WO 2013/029686 , for example. Surprisingly, the inventors have found that by restricting detachment of the air flow from the inside surface at this point by using a chamfer or curve as described above then there is a significant reduction in noise from the air flow guide system, especially with fans circulating a higher flow rate of air. This allows for quieter running and/or for improved fans to be used without the negative impact of increased noise. That is to say, with all else being equal then the proposed curved or chamfered surface will reduce the noise produced during use of the refrigerated display case compared to the use of a 90° bend in place of the chamfered/curved portion, as in the prior art disclosure of WO 2013/029686 .
It will be appreciated that the refrigerated display case is oriented in use with a top and a base, and hence as used herein references to horizontal and vertical should be understood with reference to that orientation. The refrigerated display case has a vertical extent between the top and the base thereof, and a horizontal extent between the front and back (a depth of the case), as well as between two sides (a width of the case). The storage space may be accessible from a 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 a horizontal direction, but that need not be exactly horizontal. The horizontal extent of the inlet air passage in the direction of flow of air extends from the front of the case toward the back, and it may terminate at the low pressure space. The inlet air passage also has a horizontal extent transverse to the direction of flow of air, and this may be at least the width of the fan, optionally larger than the fan, and may span a major portion of the width of the case. The corner may have a horizontal extent transverse to the direction of flow of air that is at least the width of the fan, optionally larger than the fan, and may span a major portion of the width of the case. In example embodiments the corner has a width is at least as large as the width of the inlet air passage. The air flow guide system of the first aspect gives added advantages when the corner and the inlet air passage are relatively wide, and this type of refrigerated display case is to be differentiated from those which use relatively narrow passages, such as passages that funnel air through flow paths that in their narrowest point occupy only a minor portion of the width of the case and that may be narrower than the width of the fan. In fact, as discussed further below, the inlet air passage and other parts of the air flow guide, in particular the corner, may provide a flow path for air travelling toward multiple fans, such that the width of the inlet air passage and of the corner extend over a width of the case including the multiple fans.
The low pressure space may be toward the rear of the refrigerated display case compared to the location of the fan, or it may be toward the front of the case compared to the location of the fan, with the high pressure space being the other side of the fan. The corner may be on the inside surface that extends between an upper boundary of the inlet air passage and an internal surface of the low pressure space toward the front of the refrigerated display case. The inside surface may be a generally vertical surface.
In examples where the low pressure space is toward the front of the case then this internal surface may be located at a point between the low pressure space and the storage space. In that case the fan and the pressure boundary wall may be located across an open area of the low pressure space opposite from the internal surface that links with the corner.
Alternatively, where the low pressure space is toward the rear of the case compared to the fan then the internal surface may be a surface of the pressure boundary wall, i.e. a surface of the wall between the low pressure space and the high pressure space. The pressure boundary wall may have a vertical extent and in some examples it may be generally vertical. Thus, the corner may be at turning of the direction 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 turning through a right angle from generally horizontal to generally vertical.
The corner has an inside surface, which is a surface at the inside of the corner and may face an outside surface at the outside of the corner, with the inside and outside surfaces forming boundaries for air flow around the corner. This surface extends from the upper boundary of the inlet air passage, which may be a wall separating the inlet air passage from the refrigerated space, which is above it. The inside surface extends to the internal surface of the low pressure space, which may be the rearward surface of a generally vertical wall. The walls may be constructed as single layers or multiple layers, such as with insulation in between outer layers.
The inside surface may be either curved or chamfered and in vertical cross section viewing from a side of the refrigerated display case it is cut away or truncated compared to straight extensions of the upper boundary of the inlet air passage and internal surface of the low pressure space. The upper boundary of the inlet air passage and the internal surface of the low pressure space may, for example, be at right angles to one another so that if extended without a curve or chamfer then they would form approximately a 90° bend. The curve or chamfer truncates this 90° bend within an extent of at least 10 mm in the vertical and horizontal. Thus, for example, the curve may be a quarter circle of radius 10 mm, or some other circular arc with a larger radius spanning a chord length of at least about 14 mm. Alternatively, a chamfered portion may truncate the inside surface across a length of at least about 14 mm, such as with a 45° chamfer (i.e. two corners with outside angle of 135°) providing a diagonal within an extent of at least 10 mm in the vertical and horizontal. Thus, the curve or chamfer may span a length of at least 14 mm in a diagonal that extends tangent to the direction of air flow around the corner. The vertical and/or horizontal extent of the curve or chamfer may be larger than 10 mm, such as being at least 15 mm, or at least 20 mm in one or both the vertical and horizontal. More than one chamfer may be used, thus providing multiple straight sections around the inside surface of the corner. The inside corner may also include combinations 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 and horizontal extent of the curve or chamfer may be at least 10% of the vertical extent of the inlet air passage, optionally at least 15%. These dimensions will provide sufficient air volume for refrigeration of a typical refrigerated space.
The fan may be located above the corner within the pressure boundary wall. Thus, the fan may be housed in an opening through the pressure boundary wall. In the case of a generally vertical wall the fan (in the case of a fan with axial flow) is hence mounted with a generally vertical arrangement of the fan blades, and a generally horizontal axis of rotation for the fan blades. A typical fan may have a diameter at least 200 mm, e.g. about 250 mm. In some examples, the fan comprises blades with both radial and axial elements, i.e. it may be of a mixed flow type such as being an axial fan with radial components. For example the fan blades may have tip fences. Optionally, the fan orifice comprises an inflow straightener. It has been found that there are particular benefits for noise reduction when the proposed curved or chamfered corner is used with such fans. There may be multiple fans spaced apart across a width of the refrigerated display case between two sides thereof, for example, 3, 4, 5 or more fans. The width of the corner may span the location of more than one fan, preferably all of the fans. Thus, the air flow guide system may convey air to multiple fans. The air inlet passage, as well as the corner, may provide an air flow to multiple fans, with each of the multiple fans drawing air from the same space. Advantageously with this arrangement if one fan fails then the full width of the air inlet passage may still be utilised to draw air into the low pressure space, since the low pressure space may be common to all fans and/or since the other (non-failed) fans can draw air from the common air inlet passage. Optionally the inlet air passage is common to all of the fans and there is a single low pressure space and single high pressure space that are both common to all of the fans.
The fan(s) drive air flow through the outlet into the storage space of the refrigerated display case. This allows for cooling as the air may also pass a heat absorbing heat exchanger for cooling the air, which as discussed below may be placed before or after the fan(s). In some examples, the fan(s) also drive air flow through an air curtain system in which uncooled air provides an air curtain at the front of the refrigerated display case to aid retention of cooled air within the storage space. Thus, the fan (or multiple fans) may provide increased air pressure to the high pressure space, which then may direct air flow partially through a heat absorbing heat exchanger for cooling the air, and then to the outlet into the storage space, and may direct air flow partially bypassing the heat absorbing heat exchanger and through an air curtain air flow path. Thus, the high pressure space may provide air flow for both cooling air and an uncooled air curtain.
The refrigerated display case includes a foot part placed within the inlet air passage. Such a foot part is present in order 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 foot part may support at least a portion of the weight of the pressure boundary wall and/or the fan. Alternatively or additionally the foot part may support at least a proportion of the weight of shelving and goods, where present, within the refrigerated space, such as by supporting a vertical rail that holds the shelving and goods, where present. In some examples there are multiple foot parts space apart along a width of the refrigerated display case between two sides thereof, i.e. multiple foot parts space apart along a width of an opening that forms a part of the inlet air passage.
The foot part(s) may span the vertical extent of the inlet air passage as well as spanning a part of the width thereof. The foot part(s) may hence transfer vertical load from above the inlet air passage to a base thereof, which may be the base of the refrigerated display case.
In example embodiments the foot part(s) are arranged for through flow of air. Thus they may have one or more internal passages for air that are 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 the low pressure space. The internal passages of the foot part(s) may be multiple parallel passages.
The refrigerated display case may comprise at least one foot part located beneath, or close to, a fan, with the at least one foot part beneath the fan also optionally supporting a vertical rail for supporting shelves of the refrigerated space.
The refrigerated display case may include a heat absorbing heat exchanger for cooling the air. For example, the heat absorbing heat exchanger may be placed before or after the fan. In one possible implementation, warm return air passes along the inlet air passage, into the low pressure space, through the fan, and then through the heat absorbing heat exchanger. In that case at least a portion of the air from the high pressure space may be routed through the heat absorbing heat exchanger before being directed into the refrigerated space for cooling refrigerated goods therein. Optionally, a different portion of the air from the high pressure space may bypass the heat absorbing heat exchanger in order to provide a flow of non-cooled air for an air curtain at the front of the refrigerated display case.
The heat absorbing heat exchanger may be an evaporator of a refrigeration circuit, with the refrigeration circuit optionally being incorporated in the refrigerated display case.
Viewed from a second aspect, the invention provides a method for manufacturing a refrigerated display case with an air flow guide system as described above in relation to the first aspect. Thus, a method of manufacture may comprise providing a refrigerated display case including a storage space accessible from a front of the refrigerated display case and an air flow guide system for supplying refrigerated air to the storage space, forming the air flow guide system with: an inlet air passage extending in a horizontal direction from the front of the refrigerated display case toward a back of the refrigerated display case; a corner where the air flow exits the inlet air passage and turns toward a vertical direction; a low pressure space after the corner; a pressure boundary wall separating the low pressure space from a high pressure space; and at least one outlet for directing the air flow from the high pressure space to cool the storage space; providing a fan for generating a pressure difference 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 it out of the at least one outlet; and the method comprising forming the corner with a curved or chamfered portion on the inside surface extending between an upper boundary of the inlet air passage and an internal surface of the low pressure space, with the curved or chamfered portion of the inside surface extending at least 10 mm in both the vertical and horizontal directions, characterised by providing at least one foot part placed within the inlet air passage, wherein the foot part supports at least a portion of the weight of one or more components of the refrigerated display case that are placed above the inlet air passage.
The air flow guide system may be provided any other feature as discussed above.
Certain preferred embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which:

Figure 1 shows a cross-section for a known refrigerated display case;
Figure 2 is a front view of an internal layout for fans of a known refrigerated display case;
Figure 3A is a close-up cross-section of a back corner of a proposed refrigerated display case showing detail of an air flow path;
Figure 3B shows an alternative arrangement for the air flow path at the back corner;
Figure 4 is a front view of an example internal layout for fans of the proposed refrigerated display case;
Figure 5 shows another example internal layout for fans of the proposed refrigerated display case;
Figure 6 is a perspective view of an air through flow foot part that can be used within the air flow path of Figure 3A or Figure 3B; and
Figure 7 is a perspective view of an alternative design for an air through flow foot part that can be used within the airflow paths of Figure 3A or Figure 3B.

In Figure 1 a known refrigerated display case 2, as discussed in WO 2013/029686 , is shown in a schematic side view, with the side wall/side cover removed in order to give a good view into the refrigerated space 10 (also described as a goods presentation space 10). It will be appreciated that whilst the refrigerated display case 2 of Figure 1 is a known design, the features of this case may be usefully modified with the air flow path, the fan and/or the air through flow foot part described below with reference to Figures 3A to 7. Thus, examples utilising the features described in connection with Figures 3A to 7 may include the air flow features described here in relation to Figure 1. The refrigerated display case 2 is of the front access type and can also be called a refrigerated sales cabinet. The refrigerated display case 2 allows for a substantially horizontal access to the goods presented therein by a customer standing in front of the refrigerated display case 2 (to the right in Figure 1).
The refrigerated display cases described herein can be operated at normal cooling temperatures of above 0 °C or at freezing temperatures of below 0 °C, depending on the type of refrigerated goods.
Although the refrigerated display case 2 of Figure 1 is open at its front access side it also can be equipped with sliding or pivoting doors at its front access side that have to be opened in order to get access to the goods presentation space 10. Alternatively the front access side can be shielded by curtains or a blind. The refrigerated display case of Figure 1 comprises a horizontal base 4 that can be provided with stands (not shown), an upright display case rear wall 6 extending from the rear end of the base 4 that is typically positioned in front of a building wall, or back-to-back with other retail display furniture, such as another similar display case 2, and a top 8 that extends over the refrigerated space 10. The base 4, the display case rear wall 6 and the top 8, along with side walls (not shown), enclose the interior space of the refrigerated display case 2, which includes the refrigerated space 10 as its major part. The refrigerated space 10 is a goods presentation space 10, which is confined by a goods presentation space bottom wall 14, by a perforated goods presentation space rear wall 16 and by an upper goods presentation space wall 19.
The refrigerated display case 2 also includes air channels 20, 32, 48, 60, a fan 30 and an evaporator 46 that are at least partly located outside of the goods presentation 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 an air suction channel 20 is arranged between the base 4 and the goods presentation space bottom wall 14 and substantially horizontal channel portions 52 and 64 of a cold air channel 48 and a warm air channel 60 extend between the upper goods presentation space wall and the top 8.
In this example there are three goods presentation shelves 70, 72 that can be fastened by appropriate means to the perforated goods presentation space rear wall 16 and goods presentation space side walls (not shown), which extend substantially horizontally and carry the goods to be presented and sold. Although three goods presentation shelves 70, 72 are shown in Figure 1, any suitable number of goods presentation shelves can be provided within the goods presentation space 10.
Optionally, the refrigerated display case 2 can include a goods compartment below the lowermost of the goods presentation shelves 70, 72. In that case the lowermost of the three goods presentation shelves 70 is formed as an air guiding goods presentation shelf 72. Cold air from the cold air channel 48 (described below) can flow into the interior of the air guiding shelf 72 as shown, and is directed through appropriate openings at the underside of such a shelf 72 in a generally vertical direction and downward to the goods compartment lying underneath the air guiding shelf 72. In Figure 1 the goods compartment is in the bottom area/base compartment 12 of the refrigerated display case 2. By the use of this type of air guiding goods presentation shelf 72, an efficient cooling of the goods positioned in the compartment underneath can be attained. In other variations, the open fronted refrigerated space 10 may extend lower within the refrigerated display case and in that case the goods presentation shelves may include one or more further shelf lower down, in place of the goods compartment. A removable bumper 76 can be placed at a 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 entry opening 22 of an air suction channel 20, which forms an inlet air passage 20 into which relatively warm return air enters. The return air is conveyed through a substantially horizontal air suction channel portion 24 arranged between the base 4 and the goods presentation space bottom wall 14 and through a substantially vertical rear air suction channel portion 26. The rear air suction channel portion 26 is a low pressure space 26 arranged at a position behind the bottom area 12 of the goods presentation space 10 and adjacent to and substantially in parallel to the display case rear wall 6. The return air enters this low pressure space 26, which is at a lowered air pressure due to a fan 30 that sucks the relatively warm return air through such air suction channel 20 and pushes it through an air pressure channel 32, which hence forms a high pressure space 32, where the air pressure is higher than that of the low pressure space 26 during operation of the fan 30.
From the high pressure space 32 the air passes through a heat absorbing heat exchanger 46, for example an evaporator 46, through a 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 a heat absorbing heat exchanger 46 after the fan 30 could be switched with an alternative arrangement in which the a heat absorbing heat exchanger 46 exchanges heat with the air before the fan 30, such as within the horizontal air suction channel portion 24.
A bottom portion 34 of the high pressure space 32 extends in front of and substantially in parallel to the low pressure space 26 at the end of the air suction channel 20. The low pressure space 26 is separated from the bottom portion 34 of the high pressure space 32 by a vertical wall 28, which is hence a pressure boundary wall 28. Whilst this wall is described herein as vertical, it will be appreciated that it does not need to be vertical and in variations of the depicted embodiments it could vary from vertical whilst the same basic effect is achieved, i.e. separation of the low and high pressure areas, and supporting the fan 30. The fan 30 is arranged in an appropriate opening of the vertical wall 28, and aside from this opening the wall 28 may be sealed to prevent air moving between the high pressure space 32 and the low pressure space 26. The high pressure space 32 also has an 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 cold air channel 48. It will be understood that it is possible to have several fans 30 across the width of the refrigerated display case 2, as shown in Figure 2 for example.
The cold air channel 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, the cold air channel 48 distributes air to the refrigerated space 10 through suitable openings in the perforated goods presentation space rear wall 16, as well as allowing air to move to the top 8 and the base of the refrigerated display case 2. Toward the base, and around the height of the fan 30, a second vertical wall 42 separates the high pressure space 32 from bottom part of the cold air channel 48.
In order to provide for an air curtain, a warm air channel 60 allows for air from the high pressure space 32 to bypass the heat absorbing heat exchanger 46 and flow through a vertical warm air channel portion 62 at the rear of the case 2. The warm air channel 60 extends along the display case rear wall 6 and the top 8 to a warm air curtain opening 66, which can be a honeycomb opening, which is positioned at the front of the top 8. In parallel with the top warm air channel portion 64 the generally horizontal cold air channel portion 52 delivers cold air from the cold air channel 48 to the front of the top 8, where there is a cold air curtain opening 56 as described below. The partial air flow 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 opening 66 and forms a curtain of warm air 68 in front of the goods presentation space 10 extending between the warm air curtain opening 66 and the air entry opening 22 of the air suction channel 20.
The partial air flow flowing through the heat absorbing heat exchanger 46 is cooled in the heat absorbing heat exchanger 46, for example via heat exchange against a refrigerant circulating in a refrigeration cycle. The air exiting the heat absorbing heat exchanger 46 from its upper outlet side is called cold discharge air, and it leaves the cold air channel 48 from which it is supplied as cooling air flow to the goods presentation space 10 from the back through the perforated goods presentation space rear wall 16 and as cold air curtain flow to an air curtain opening 56 positioned at the front of the top 8 adjacent to and immediately behind the warm air curtain opening 66 so as to form a curtain of cold air 58 flowing from the cold air curtain opening 56 along the front side of the goods presentation space 10 to the air entry opening 22 of the air suction channel 20. The curtain of cold air 58 is formed behind the curtain of warm air 68, which has been found to be particularly effective for reducing the amount of warm air entering into the goods presentation space 10 from the front.
As noted above, the heat absorbing heat exchanger 46 can be an evaporator 46, which 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 serially so as to form a closed refrigeration cycle.
The refrigerated display case 2 may include multiple fans 30 spaced apart across a width of the display case 2. A possible arrangement is shown in Figure 2, where the front parts including the shelves 70, 72, the rear wall 16 of the refrigerated space 10 and enclosures of the rear air passages are removed in order that the fans 30 can be seen mounted within the generally vertical wall 28 that separates the low pressure space 26 and the high pressure space 32. The low pressure space 26 is enclosed within the vertical rear wall 28 and a horizontal upper enclosure portion spanning between the vertical rear wall 28 and the display case rear wall 6. The high pressure space 32 sits forward of the fan 30 and the air channel 48 would extend upward along the height of the display case rear wall 6. The inlet air passage 20 runs along the base 4 and when the refrigerated display case 2 is fully assembled this would be enclosed on its upper side by a bottom wall 14 of the refrigerated space 10.
In this example there are six fans 30 spaced apart across the width of the refrigerated display case 2, which may for example be a width of 3.75 m. The fans 30 connect to common low and high pressure spaces 26, 32. Each fan 30 is below a condensate guard 78, i.e. a horizontally protruding element for shielding the fan 30 from any drips of condensation that may form in the air passages above. Also visible in Figure 2 are foot parts 80, which are spaced apart along an opening at the base of the vertical wall 28. The opening at the base of the vertical wall 28 forms a part of the inlet air passage 20. The foot parts 80 span the opening and hence span the vertical extent of the inlet air passage 20 in order to provide support for parts of the refrigerated display case 2 above the opening, which includes the vertical wall 28 with the fans 30 held therein, as well as the rear wall 16 of the refrigerated space 10. It will be appreciated that this rear wall 16 provides support for the shelves 70, 72, such as via vertical rails 84 of the type described below with reference to Figure 4, which in Figure 2 can be aligned with the vertical markings 82 on the display case rear wall 6. Thus, in some instances the foot part 80 will directly bear a portion of the weight of the shelves 70, 72 (and the goods thereon) via one of the vertical rails 84.
Advantageously, the design for the refrigerated display case 2 of Figure 1 is modified as shown in Figure 3A or Figure 3B. This Figure shows an enlarged view of a rear corner of the refrigerated display case 2 including parts of the display case rear wall 6 and the base 4. As with the arrangement of Figure 1, a low pressure space 26 and a high pressure space 32 are separated from each other by a vertical wall 28, but in this case the wall holds a fan 130 that uses both axial and radial flow elements, such as by including tip fences, in order to enhance the performance of the fan 130. In Figure 3A the fan 130 is in the same orientation of Figure 1. In Figure 3B, as discussed in more detail below, the fan 130 is in the opposite orientation, so that the low pressure space 26 and high pressure space 32 switch positions. The arrangement of the refrigerated space 10 and the air passages at parts of the refrigerated display case 2 not shown in Figure 3A and Figure 3B may be similar to those in Figure 1, such as via the use of partial warm/cold flows and an air curtain. The refrigerated display case 2 of Figure 3A or Figure 3B may include a heat absorbing heat exchanger 46 similarly placed to the evaporator 46 of Figure 1, or it may cool the air through some other placement of a heat absorbing heat exchanger.
Considering the arrangement of Figure 3A in more detail, the air flow guide system in Figure 3A differs in significant respect with reference to the arrangement of Figure 1 in relation to the connection between the inlet air passage 20 and the low pressure space 26. In particular, it can be seen that in Figure 1, in line 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 vertical wall 28 that encloses the low pressure space 26. In contrast, in the example illustrated by Figure 3A there is a corner 88 that includes a chamfered portion 90 on the inside surface extending between an upper boundary 92 of the inlet air passage 20 and a low pressure facing surface of the wall 28. The chamfered portion 90 may alternatively be replaced with a curved portion. The curved or chamfered portion at the corner 88 extends in both the vertical and horizontal directions in order to minimise flow separation at the corner 88. In this example the chamfer has two 135° edges in place of the single 90° edge of Figure 1, and the vertical and horizontal extent of the chamber is about 25 mm. By adjusting the form of the inside surface and avoiding the 90° edge of Figure 1 then separation of air flow is avoided and this has been found to contribute to a reduction in noise, especially in circumstances where a fan 130 with axial and radial blade elements is used.
The fan 130 can be a fan having tip fences on the fan blades, such as a fan as disclosed in US 2019/234419 , for example. As noted above, the benefits from the modifications to the air flow path give particular advantages when combined with improvements to the design for the fan 130, since the benefit of noise reduction is increased.
Turning now to Figure 3B, a similar modification is shown for the flow path in the situation where direction of the airflow through the fan 130 is toward the rear of the refrigerated display case 2 rather than toward the front thereof. As a consequence, the low pressure space 26 moves toward the front of the case 2, sitting next to 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, sitting next to the outer rear wall 6 of the refrigerated display case 2. With this alternative arrangement the corner 88 is on the inside surface extending between an upper boundary 92 of the inlet air passage 20 and an inner surface of the low pressure space, which is a surface of the rear wall 16 of the refrigerated storage space 10. The air flows rearward through the fan 130 to the high pressure space, then upward toward flow paths similar to those shown in Figure 1, such as passing via a heat exchanger 46 and/or into a separate flow path for an air curtain arrangement.
An added feature of the example embodiments of Figure 3A and Figure 3B is that the internal layout and number of the fans 130 can be adjusted compared to that shown in Figure 2, with the spacing potentially being increased where improved fans 130 are used, since fewer fans 130 can provide the same air flow. The result of this may be an arrangement as shown in Figure 4, which has fewer fans 130 for the same width than that shown in Figure 5, both of which depict a refrigerated display case 2 having a width of 2.5 mm. As with Figure 2, Figures 4 and 5 show an internal view of the rear of the refrigerated display case 2 at the lower part thereof where the front parts including the shelves 70, 72, the rear wall 16 of the refrigerated space 10 and enclosures of the rear air passages are removed in order that the fans 130 can be seen mounted within the generally vertical wall 28 that separates the low pressure space 26 and the high pressure space 32. The inlet air passage 20 runs along the base 4 and when the refrigerated display case 2 is fully assembled this would be enclosed on its upper side by a bottom wall 14 of the refrigerated space 10. In Figure 4 there are three fans 130 spaced apart across the 2.5 m width of the refrigerated display case 2, with hence a reduced number of fans 130 compared to Figure 5, where four fans 130 are used. This can lead to cost savings.
Figures 4 and 5 also show foot parts 80 that is used in a similar way to the foot parts 80 in Figure 2, providing support to the vertical wall 28 that holds the fans 130, as well as supporting at least part of the weight from the shelves 70, 72 via one or more shelf support rail 84, shown in Figure 4. The example in Figure 5 could likewise include a rail 84 supported by the central foot part 80. It will be noted that Figures 4 and 5 are absent the condensate guard 78. This is possible since the fan 130 includes a fan orifice 79 that extends forward of the pressure boundary wall 28. The upper part of the fan orifice 79 acts as a condensate guard meaning that a separate condensate guard 78 can be omitted.
Further changes to the air flow may be provided by the use of a foot part 80 permitting through-flow of air, for example as shown in Figure 6 or Figure 7. With reference to Figures 3A, 3B, 4 and 5 and the discussion above, the foot part 80 sits within the opening at the base of the vertical wall 28 that separates the low pressure space 26 and the high pressure space 32. The foot part 80 extends across the height of the inlet air passage 20. It will be seen that the foot part 80 obscures only a small portion of the opening for air to enter the low pressure space 26. However, it will nonetheless affect the air flow. In the past a foot part 80 with enclosed walls has been used, with those walls blocking the air flow and diverting it around the foot part 80. This hinders the air flow and adds turbulence, potentially increasing the noise from the refrigerated display case 2. Improvements are provided when the air can flow through the foot part 80. It will be appreciated that these improvements are particularly significant where the foot part 80 is close to the fan 130, especially when it is directly beneath the fan 130 as with the central foot part 80 in Figure 4.
With reference to Figure 6 and 7 the proposed through flow foot parts 80 include a through flow passage between an inlet 94 at an upstream end of the foot part 80 and an outlet 96 at a downstream end of the foot part 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 openings facing both vertically and horizontally. The foot part 80 includes an upper load bearing surface 98, which is advantageously flat and can receive the weight of various parts of the refrigerated display case 2 above the foot part 80. In order to transfer loads from the upper load bearing surface 98 to the bottom of the foot part 80, which sits on the base 4 of the refrigerated display case 2, the foot part 80 includes side walls 99.
Figure 6 shows an example of the foot part 80 that may be moulded in plastic. It includes internal walls that add strength and form the boundaries of multiple internal flow paths. The multiple internal flow paths together form the through flow passage between the inlet 94 and the outlet 96. Figure 7 shows an alternative design that may be stamped or folded from sheet metal, with a fully open through flow passage between the inlet 94 and the outlet 96.

Claims

A refrigerated display (2) case including a storage space (10) and an air flow guide system (20, 88, 26, 28, 32) for supplying refrigerated air to the storage space, the air flow guide system (20, 88, 26, 28, 32) comprising:
an inlet air passage (20) extending in a horizontal direction from the front of the refrigerated display case (2) toward a back of the refrigerated display case (2);

a corner (88) where the air flow exits the inlet air passage (20) and turns toward a vertical direction passing around an inside surface of the corner (88);

a low pressure space (26) after the corner (88);

a pressure boundary wall (28) separating the low pressure space (26) from a high pressure space (32);

at least one outlet for directing the air flow from the high pressure space (32) to cool the storage space (10); and

a fan (130) for generating a pressure difference between the low pressure space (26) and the high pressure space (32) to thereby draw air through the inlet air passage (20) and around the corner (88) before driving it out of the at least one outlet;

wherein the corner (88) includes a curved or chamfered portion (90) on the inside surface extending between an upper boundary of the inlet air passage (20) and an internal surface of the low pressure space (26), with the curved or chamfered portion (90) of the inside surface extending at least 10 mm in both the vertical and horizontal directions, characterised by

at least one foot part (80) placed within the inlet air passage (20), wherein the foot part (80) supports at least a portion of the weight of one or more components of the refrigerated display case (2) that are placed above the inlet air passage.
A refrigerated display case (2) as claimed in claim 1, wherein the inside surface of the corner (88) is cut away or truncated compared to straight extensions of the upper boundary of the inlet air passage (20) and the internal surface of the low pressure space (26), with the cut-away or truncated part extending across a length of at least about 14 mm.
A refrigerated display case (2) as claimed in claim 1 or 2, wherein the vertical and/or horizontal extent of the curve or chamfer (90) is at least 15 mm in one or both the vertical and the horizontal.
A refrigerated display case (2) as claimed in claim 1, 2 or 3, wherein the width of the corner (88) in a direction corresponding to the width of the refrigerated display case (2) between two sides thereof is larger than the fan (130) diameter.
A refrigerated display case (2) as claimed in any preceding claim, wherein the fan (130) is located above the corner (88) within an opening through the pressure boundary wall (28).
A refrigerated display case (2) as claimed in any preceding claim, comprising multiple fans (130) spaced apart across a width of the refrigerated display case (2) between two sides thereof, wherein the width of the corner (88) spans the locations of more than one fan (130).
A refrigerated display case (2) as claimed in any preceding claim, wherein the fan (130) comprises blades having tip fences and/or wherein the fan (130) is of a mixed flow type.
A refrigerated display case (2) as claimed in any preceding claim, wherein the foot part (80) supports at least a proportion of the weight of shelving (70, 72) within the refrigerated space (10) by supporting a vertical rail (84) that holds the shelving (70, 72).
A refrigerated display case (2) as claimed in any preceding claim, wherein the foot part (80) spans the vertical extent of the inlet air passage (20) as well as spanning a part of the width thereof and transfers vertical load from above the inlet air passage (20) to a base thereof.
A refrigerated display case (2) as claimed in any preceding claim, wherein the foot part (80) is arranged for through flow of air and has one or more internal passages (94) that are arranged to receive air from an upstream location (94) in the air flow path (20) and discharge air to a downstream location (96) in the air flow path (20).
A refrigerated display case (2) as claimed in any preceding claim, comprising a plurality of foot parts (80) wherein at least one foot part (80) is located beneath or close to a fan (130) and supports a vertical rail (84) for supporting shelves (70, 72) of the refrigerated space (10).
A refrigerated display case (2) as claimed in any preceding claim, comprising a heat absorbing heat exchanger (46) for cooling the air.
A method for manufacturing a refrigerated display case (2) with an air flow guide system (20, 88, 26, 28, 32), the method comprising:
providing a refrigerated display case (2) including a storage space (10) and an air flow guide system (20, 88, 26, 28, 32) for supplying refrigerated air to the storage space (10), forming the air flow guide system (20, 88, 26, 28, 32) with:
an inlet air passage (20) extending in a horizontal direction from the front of the refrigerated display case (2) toward a back of the refrigerated display case; a corner (88) where the air flow exits the inlet air passage (20) and turns toward a vertical direction passing around an inside surface of the corner (88); a low pressure space (26) after the corner (80); a pressure boundary wall (28) separating the low pressure space (26) from a high pressure space (32); and at least one outlet for directing the air flow from the high pressure space (32) to cool the storage space (10);

providing a fan (130) for generating a pressure difference between the low pressure space (26) and the high pressure space (32) to thereby draw air through the inlet air passage (20) and around the corner (88) before driving it out of the at least one outlet; and

forming the corner (88) with a curved or chamfered portion (90) on the inside surface extending between an upper boundary of the inlet air passage (20) and an internal surface of the low pressure space (26), with the curved or chamfered portion (90) of the inside surface extending at least 10 mm in both the vertical and horizontal directions, characterised by

providing at least one foot part (80) placed within the inlet air passage (20), wherein the foot part (80) supports at least a portion of the weight of one or more components of the refrigerated display case (2) that are placed above the inlet air passage.
A method as claimed in claim 13, comprising providing the refrigerated display case (2) with the features of any of claims 2 to 12.