Showcase

Abstract

To provide a showcase capable of suppressing a leaked refrigerant from remaining in the vicinity of the showcase.SOLUTION: A showcase according to an embodiment includes a casing, a machine room provided in the casing, and an exhibition room having an opened front face and provided in the casing. An intake port for introducing air into the machine room and an exhaust port for discharging the air from the machine room are formed in the casing. The exhaust port is formed on an upper portion of the casing, and a back face hole communicating with the machine room is formed in a lower portion of a back face of the casing.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a showcase. [Background technology]

[0002] Patent Document 1 discloses a showcase with a machine compartment at the bottom. It describes that an air intake and an exhaust port are formed around the machine compartment, and that a condenser fan introduces air into the machine compartment through the air intake and exhausts air from the machine compartment through the exhaust port. Patent Document 1 also discloses a technique for diffusing leaked refrigerant by driving the condenser fan and the evaporator fan. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-89113 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a showcase that can prevent leaking refrigerant from accumulating near the showcase. [Means for solving the problem]

[0005] The showcase of the present disclosure comprises a housing, a machine compartment provided in the housing, and a display compartment with an open front provided in the housing, wherein the housing is formed with an air intake port for introducing air into the machine compartment and an exhaust port for exhausting air from the machine compartment, the exhaust port being formed in the upper part of the housing, and a rear hole communicating with the machine compartment being formed in the lower part of the rear of the housing. [Effects of the Invention]

[0006] The present disclosure can provide a showcase that can prevent leaking refrigerant from accumulating near the showcase. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a showcase according to a first embodiment; [Figure 2] FIG. 2 is a longitudinal cross-sectional view of the showcase in the first embodiment taken along line II-II of FIG. [Figure 3] 1 is a rear view of a showcase according to a first embodiment; [Figure 4] FIG. 1 is a front view of the showcase 1 in a state where an upper front panel and a duct plate are removed according to the first embodiment. [Figure 5] FIG. 1 is a plan view showing the inside of a machine room of a showcase according to a first embodiment. [Figure 6] Cross section of Figure 5 taken along line VI-VI [Figure 7] FIG. 1 is a left side view of a showcase according to a first embodiment. [Figure 8] FIG. 10 is a diagram showing the relationship between the refrigerant concentration C near the lower rear surface of the showcase in the first embodiment and the showcase in the comparative example and time T. [Figure 9] FIG. 10 is a diagram showing the relationship between refrigerant concentration C near the front lower portion of the left side surface of the showcase in the first embodiment and the showcase in the comparative example and time T. DETAILED DESCRIPTION OF THE INVENTION

[0008] (Findings that formed the basis of this disclosure) At the time the inventors arrived at the idea of ​​the present disclosure, it was known that in showcases, refrigerant may leak from any part of the refrigerant circuit that constitutes the refrigeration cycle due to aging, etc. Hereinafter, refrigerant leaking from any part of the refrigerant circuit that constitutes the refrigeration cycle of a showcase will also be simply referred to as "leaked refrigerant." Here, among showcases, there is known one in which a machine compartment is provided at the bottom and an air intake port and an exhaust port are provided at the front and rear of the machine compartment. In such showcases, it is known that leaked refrigerant is less likely to accumulate near the bottom of the back of the showcase because airflow is generated by the air intake port and the exhaust port. The air flowing out of the exhaust port, or so-called exhaust air, tends to become hot and rise. Therefore, some showcases are known that have an exhaust port from a machine compartment at the top of the showcase to suppress temperature changes around the showcase. In such showcases, if a refrigerant leaks in the machine compartment, the refrigerant is easily discharged from the upper exhaust port along with the exhaust air and diffuses. Therefore, even in showcases with an exhaust port at the top, it was thought that the leaked refrigerant would not accumulate near the lower back of the showcase. However, the back of a showcase is often placed adjacent to a wall of a store, making it difficult for the leaked refrigerant to diffuse. Furthermore, if the refrigerant is heavier than air, the refrigerant tends to move downward. Therefore, the leaked refrigerant tends to accumulate near the lower back of the showcase, increasing the concentration of the leaked refrigerant in the air (hereinafter simply referred to as the "leaked refrigerant concentration"). The inventors discovered a problem. To solve this problem, they came up with the subject matter of the present disclosure. Therefore, the present disclosure provides a showcase that can prevent leaking refrigerant from accumulating near the showcase.

[0009] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0010] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0011] [1-1.Configuration] [1-1-1. Showcase Configuration] FIG. 1 is a perspective view of a showcase 1 according to the first embodiment. The showcase 1 is an open showcase for freezing and refrigerating that can be installed in stores such as supermarkets and convenience stores. In the description of this specification, when front, back, left, right, top and bottom are used for the showcase 1, the front side as seen from the user using the showcase 1 corresponds to the front side of the showcase 1, and the back side corresponds to the rear side of the showcase 1. Furthermore, the left side as seen from the user using the showcase 1 corresponds to the left side of the showcase 1, and the right side corresponds to the right side of the showcase 1. Specifically, the directions indicated by arrows FR, RE, LE, RI, UP, and DO in each figure will be described as corresponding to front, back, left, right, top and bottom of the showcase 1. The front of the showcase 1 may also be referred to as the front. The rear of the showcase 1 may also be referred to as the back. Furthermore, the left-right direction of the showcase 1 may also be referred to as the width direction.

[0012] Fig. 2 is a vertical cross-sectional view of the showcase 1 in the first embodiment taken along line II-II in Fig. 1. Fig. 2 can also be said to correspond to the cross-section of line II-II in Fig. 3. The showcase 1 has a housing 1a. The housing 1a is provided with an insulating wall 2 having an enclosed shape with a U-shaped cross section. Side panels 3 are attached to both sides of the insulating wall 2 in the width direction. The insulating wall 2 and the pair of left and right side panels 3 form a main body 4 that is open to the front. A duct plate 6 is attached to the inside of the enclosed shape of the insulating wall 2, spaced apart from the inner surface of the insulating wall 2, so as to span the bottom, back, and top surfaces of the insulating wall 2. A cold air duct 7 is formed between the duct plate 6 and the insulating wall 2. Furthermore, a display chamber 8 that is open to the front is formed inside the enclosed shape of the duct plate 6.

[0013] The cold air duct 7 has a U-shaped cross section that runs along the inner surface of the heat-insulating wall 2. The upper front end of the cold air duct 7 is connected to a cold air outlet 7a located at the upper edge of the front opening 8a of the display chamber 8. The lower front end of the cold air duct 7 is connected to a cold air inlet 7b located at the lower edge of the front opening 8a of the display chamber 8. An evaporator (heat exchanger) 34 that forms part of the refrigeration cycle is disposed in the lower center of the back side of the cold air duct 7. A cold air blower 38 is disposed in the lower part of the cold air duct 7.

[0014] The cold air intake port 7b is located on the top surface of the roughly box-shaped cold air intake member 9. In other words, the interior of the cold air intake member 9 forms part of the cold air duct 7. An upper front panel 17 made of steel plate is arranged in front of the cold air intake member 9. The upper edge of the upper front panel 17 forms the lower edge of the front opening 8a of the display room 8. A night cover 10 (see Figure 1) is stored in the cold air intake member 9 and can be pulled out to close the front opening 8a of the display room 8 when the store is closed.

[0015] In FIG. 1, the night cover 10 is a sheet made of a transparent resin material. The night cover 10 is formed to be approximately the same size as the front opening 8a. When in use, the night cover 10 is pulled upward from the cool air intake member 9, and the engaging member 10a at the upper end is hooked onto the engaging portion 8b provided on the upper edge of the front opening 8a of the display chamber 8. This keeps the night cover 10 in a state where it covers almost the entire front opening 8a. A gap S is created between the night cover 10 and the side panel 3.

[0016] As shown in FIG. 2, a machine room 11 is provided below the display room 8, sandwiching the insulating wall 2 therebetween. The machine room 11 is provided below the bottom surface of the insulating wall 2. The machine room 11 is formed by an enclosed shape including a rectangular bottom panel 12, a front panel (front) 13 arranged in front of the bottom panel 12, a side panel (side) 14 (see FIG. 1) arranged to the left of the bottom panel 12, a side panel 15 arranged to the right of the bottom panel 12, a back panel (back) 16 arranged to the rear of the bottom panel 12, and the bottom surface of the insulating wall 2 above. The bottom panel 12, the front panel 13, the side panel 14, the side panel 15, and the back panel 16 are made of steel plates. A drain pipe 21 extending to the machine room 11 is supported on the bottom surface of the insulating wall 2. Inside the machine room 11, there are installed a compressor 31 and a condenser 32 which together with the evaporator 34 form a refrigeration cycle, a condenser fan 37 which generates air flow through the condenser 32, and evaporation units 41 and 44 which receive drain water dropping from the drain pipe 21.

[0017] FIG. 3 is a rear view of the showcase 1 according to the first embodiment. The rear panel 16 is formed as a single plate large enough to cover the machine room 11 and the display room 8 from the rear. The rear panel 16 is attached to the rear surface of the heat-insulating wall 2 with a predetermined distance between them. An exhaust duct 22 extending in the vertical direction is formed between the rear panel 16 and the heat-insulating wall 2. The lower end of the exhaust duct 22 opens at the top of the rear end of the machine room 11 and communicates with the machine room 11. The upper end of the exhaust duct 22 communicates with an exhaust port 22a located at the upper end of the rear surface of the showcase 1. The exhaust port 22a extends across the entire left and right sides of the showcase 1.

[0018] A top panel 18 made of a steel plate is arranged on the top surface of the showcase 1. The top panel 18 does not cover the exhaust port 22a, but covers the upper surface of the heat-insulating wall 2 from above. In this embodiment, the top panel 18, the pair of left and right side panels 3, the bottom panel 12, the front panel 13, the pair of left and right side panels 14, 15, the back panel 16, and the upper front panel 17 form a housing 1a of the showcase 1.

[0019] FIG. 4 is a front view of the showcase 1 in the first embodiment with the upper front panel 17 and the duct plate 6 removed. Shelf devices (shelf boards) 23 are arranged in the display room 8 (see Figure 2). The shelf devices 23 are supported by the main body 4. The main body 4 is provided with a plurality of support columns 24. In this embodiment, a pair of support columns 24 are arranged on both sides in the width direction of the display room 8. The support columns 24 extend in the vertical direction. A plurality of shelf devices 23 are supported on the front surfaces of the support columns 24 so that the height in the display room 8 can be changed. In this embodiment, four tiers of shelf devices 23 are supported.

[0020] The front panel 13 is disposed so as to be able to open and close the front of the machine chamber 11. The front panel 13 has uniformly formed air intake ports 13a penetrating in the thickness direction in a predetermined air intake formation area A1. Specifically, the air intake ports 13a of the same shape are repeatedly formed. In this embodiment, the air intake ports 13a are repeatedly formed in the vertical and horizontal directions. The air intake formation area A1 is biased toward the RI side (one side in the horizontal direction) with respect to the horizontal center line L0.

[0021] [1-1-2. Machine room interior configuration] 5 is a plan view showing the inside of the machine room 11 of the showcase 1 in embodiment 1. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. In the machine room 11, a compressor 31 is disposed on the bottom panel 12, which is the inner bottom surface of the machine room 11. The compressor 31 extends in the vertical direction. A condenser 32 is disposed in front of the compressor 31 with a predetermined distance therebetween. The condenser 32 is disposed adjacent to and rear of the air intake 13a. The condenser 32 is formed in an external rectangular parallelepiped shape with a size corresponding to the air intake formation area A1 of the front panel 13. The condenser 32 in this embodiment has a pipe joint 32a at which refrigerant pipes through which a refrigerant flows are connected. The pipe joint 32a is a U-bend joint of the condenser 32. The pipe joint 32a is a portion where refrigerant pipes are joined by welding.

[0022] The compressor 31 and the condenser 32 are connected by a refrigerant pipe 35. The compressor 31 and the evaporator 34 are connected by a refrigerant pipe 36. In this embodiment, a flammable refrigerant is used as the refrigerant. Specifically, propane (R290) is used as the refrigerant. The refrigerant may be a flammable refrigerant other than propane, or a slightly flammable refrigerant may be used instead of the flammable refrigerant.

[0023] Condenser fans 37 are arranged behind the condenser 32. In this embodiment, the condenser fans 37 are arranged in two rows, upper and lower. In the upper row, the condenser fans 37 are arranged in two rows in the width direction of the condenser 32. In the lower row, the condenser fans 37 are arranged in three rows in the width direction of the condenser 32. The condenser fans 37 in this embodiment are axial fans of the same shape. The condenser fans 37 take in air outside the machine chamber 11, so-called outside air, from the air intake 13a, and the outside air passes through the condenser 32 to exchange heat with the refrigerant. In other words, the condenser fans 37 forcibly draw outside air into the air intake 13a.

[0024] An upper evaporation unit 41 is disposed between the condenser fan 37 and the compressor 31. The upper evaporation unit 41 is disposed at an upper portion within the machine room 11 and spaced above the bottom panel 12. The upper evaporation unit 41 includes an evaporation pan 42 extending in the left-right direction and evaporation paper 43 supported by the evaporation pan 42. The evaporation pan 42 is configured to allow drain water flowing out from the drain pipe 21 to be introduced therein. An evaporation pipe 35a, which is part of the refrigerant piping 35 connecting the compressor 31 and the condenser 32, extends within the evaporation pan 42. As the evaporation pipe 35a extends into the evaporation pan 42, the drain water is heated by heat exchange with the refrigerant and evaporates. A plurality of evaporation papers 43 are disposed in the evaporation pan 42 to promote evaporation of the drain water received in the evaporation pan 42.

[0025] The evaporative paper 43 is a flat plate having a thickness in the left-right direction. The evaporative paper 43 is arranged at intervals in the left-right direction. Therefore, in the upper evaporation unit 41, air can easily flow between the evaporative paper 43 in the front-to-rear direction. The air flowing between the evaporative paper 43 allows the drain water sucked into the evaporative paper 43 to evaporate.

[0026] The lower evaporation unit 44 is disposed below and to the left of the upper evaporation unit 41. The lower evaporation unit 44 is disposed to the left of the condenser 32. The lower evaporation unit 44 includes an evaporation pan 45 extending in the front-to-rear direction and evaporation paper 46 supported by the evaporation pan 45. The evaporation pan 45 is configured so that drain water overflowing from the upper evaporation unit 41 can be introduced into it. The evaporation paper 46 of the lower evaporation unit 44 is flat and has a thickness in the left-to-right direction. The evaporation papers 46 are disposed with gaps in the left-to-right direction. Therefore, in the lower evaporation unit 44, air can easily flow between the evaporation papers 46 in the front-to-rear direction. The air flowing between the evaporation papers 46 allows the drain water sucked into the evaporation paper 46 to evaporate.

[0027] An evaporation fan 47 is disposed behind the lower evaporation unit 44. The evaporation fan 47 in this embodiment is an axial flow fan. The evaporation fan 47 facilitates air flow between the evaporation papers 46 of the lower evaporation unit 44.

[0028] Electrical equipment boxes 48 and 49, which house power supplies and control boards, are disposed to the right of the compressor 31, condenser 32, condenser fan 37, and upper evaporation unit 41. The electrical equipment boxes 48 and 49 have a rectangular parallelepiped appearance that extends in the front-to-rear direction. This allows air to easily flow in the front-to-rear direction near the electrical equipment boxes 48 and 49. Here, since the air in the machine room 11 is configured to rise and flow out along the exhaust duct 22, the internal pressure of the machine room 11 is likely to increase moderately due to the action of the condenser fan 37. More specifically, it has been found through experiments that the internal pressure inside the machine room 11 is higher in a showcase 1 that exhausts air from an exhaust port 22a located away from the machine room 11 via the exhaust duct 22, compared to a showcase that exhausts air from an exhaust port provided on the side of the machine room.

[0029] [1-1-3. Evaporator configuration] As shown in FIG. 4 , the evaporator 34 of this embodiment has a pipe joint 34a where refrigerant pipes through which a refrigerant flows are connected to each other. In this embodiment, the evaporator 34 is a fin-and-tube evaporator. The evaporator 34 has a plurality of U-shaped pipes (pipes) 51 extending in the left-right direction, a plurality of fins 52 provided at intervals in the extension direction of the U-shaped pipes 51, and a U-shaped connecting pipe (pipe) 53 that connects the open ends of different U-shaped pipes 51 to each other. In the evaporator 34 of this embodiment, the connecting pipe 53 is disposed on the LE side (the other side in the left-right direction) of the fin 52. In this embodiment, the connecting pipe 53 and the U-shaped pipe 51 are joined by welding. Thus, the evaporator 34 has a pipe joint 34a formed by the connecting pipe 53 and the U-shaped pipe 51.

[0030] [1-1-4. Configuration of rear holes] A rear hole 16a is formed in the lower part of the rear panel 16, penetrating in the thickness direction. The rear hole 16a is formed on a surface that forms the machine chamber 11, different from the surface on which the intake port 13a is formed. In this embodiment, the intake port 13a is formed in the front panel 13 that forms the machine chamber 11, whereas the rear hole 16a is formed in the rear panel 16 that forms the machine chamber 11. The rear hole 16a communicates with the machine chamber 11. The rear hole 16a is a hole that is small compared to the overall opening area of ​​the upper exhaust port 22a. In this embodiment, the rear hole 16a is a small hole. Here, in this embodiment, a small hole means a hole that is small enough that a finger cannot be inserted.

[0031] A plurality of rear holes 16a are formed and are arranged in a row at appropriate intervals in the left-right direction. The lower ends of the rear holes 16a are provided at a position higher than the bottom panel 12 of the machine room 11. The rear holes 16a are formed at a height corresponding to the lower part of the machine room 11 (see FIG. 2). In other words, the rear holes 16a are formed below half the height of the machine room 11 in the up-down direction. Some of the air flowing from the machine room 11 to the exhaust duct 22 flows out behind the rear panel 16 through the rear holes 16a. The rear holes 16a are holes through which air forcibly introduced into the machine room 11 by the condenser fan 37 can flow out due to the internal pressure of the machine room 11.

[0032] [1-1-5. Configuration of side holes] FIG. 7 is a left side view of the showcase 1 according to the first embodiment. A side panel 14, which is an example of the lower part of the housing 1a, is formed with a side hole 14a penetrating in the thickness direction. The side hole 14a connects the machine chamber 11 with the outside of the showcase 1. The side hole 14a is provided on the side close to the position where the gap S (FIG. 1) is generated. Specifically, the side hole 14a is formed forward of the front-to-rear center line L1 (see FIG. 7) of the side panel 14. Of the two side panels 14, 15, the side hole 14a is formed in the left side panel 14, which is closer to the pipe joint 34a (see FIG. 4) of the evaporator 34. The side hole 14a is formed as a small hole similar in size to the rear hole 16a of the rear panel 16. In this embodiment, a plurality of side holes 14a are formed at intervals in the vertical direction. Furthermore, a plurality of side holes 14a are formed at intervals in the front-to-rear direction. In this embodiment, the side hole 14a is formed above the rear hole 16a. The side hole 14a communicates with a predetermined space S1 in the machine room 11.

[0033] The predetermined space S1 is formed above the lower evaporation unit 44 (see FIG. 6). The predetermined space S1 is formed in the machine chamber 11 on the opposite side (left side) from the right side where the electrical equipment boxes 48 and 49 are arranged. The predetermined space S1 is formed forward of the drain pipe 21 and the upper evaporation unit 41 (see FIGS. 5 and 6). The predetermined space S1 is formed left of the condenser 32 (see FIG. 5). That is, the predetermined space S1 is a space surrounded by the upper evaporation unit 41, the lower evaporation unit 44, the drain pipe 21, and the condenser 32 in the machine chamber 11. The predetermined space S1 is, so to speak, a dead space in the machine chamber 11. The predetermined space S1 is a space where no components that obstruct air flow are arranged. Therefore, air from the machine chamber 11 can easily move into the predetermined space S1, and air from the machine chamber 11 can easily move into the side hole 14a that communicates with the predetermined space S1. A portion of the air flowing inside the machine room 11 flows out to the left of the side panel 14 through the side hole 14a. The side hole 14a is a hole through which the air forcibly introduced into the machine room 11 by the condenser fan 37 can flow out due to the internal pressure of the machine room 11.

[0034] [1-2. Operation] The operation of the showcase 1 configured as above will be described below.

[0035] In showcase 1, when the refrigeration cycle and cold air blower 38 are operating, cold air flows through display chamber 8 and cold air duct 7, as shown by the dashed arrows in Figure 2. That is, air is drawn into cold air duct 7 through cold air inlet 7b, flows inside cold air duct 7, and is cooled by heat exchange with the refrigerant in evaporator 34 as it passes through. The cooled air, i.e., cold air, rises inside cold air duct 7 on the rear side while being discharged into display chamber 8 from duct plate 6, and then flows into cold air duct 7 on the top side. The cold air then flows forward inside cold air duct 7 on the top side, is discharged downward from cold air outlet 7a at the front end, and flows downward while forming an air curtain at front opening 8a of display chamber 8. The cool air that reaches the bottom end of the display chamber 8 is sucked in through the cool air inlet 7b of the display chamber 8 and sent back to the cool air duct 7. In this way, the cool air circulates through the display chamber 8 and the cool air duct 7, and the inside of the display chamber 8 is cooled.

[0036] Furthermore, in the showcase 1, when the condenser fan 37 is operated, air flows through the machine room 11 and the exhaust duct 22 as shown by the solid arrows in FIGS. 2 and 5. That is, when air is forcibly introduced from the outside into the machine room 11 through the air intake 13a, the air exchanges heat with the refrigerant in the condenser 32 as it passes through, thereby increasing its temperature. The air in the machine room 11 also receives heat from the compressor 31 and the like, increasing its temperature. Most of the air with increased temperature flows to the rear of the machine room 11 and is exhausted from the upper exhaust port 22a via the exhaust duct 22. Therefore, high-temperature air, which tends to rise, is more likely to be exhausted upward than the showcase 1, and is less likely to affect the temperature environment around the showcase 1 than when it is exhausted downwards.

[0037] Here, in the showcase 1, there is a possibility that refrigerant may leak from joints where refrigerant pipes are joined due to aging or the like. For example, refrigerant may leak from joints where refrigerant pipes are joined, such as pipe joint 32a of condenser 32 (see FIG. 5), the joint between refrigerant pipe 35 and condenser 32, pipe joint 34a of the evaporator (see FIG. 7), and the joint between refrigerant pipe 36 and evaporator 34.

[0038] For example, if refrigerant leaks from the pipe joint 32a of the condenser 32, the refrigerant will leak into the machine room 11. Therefore, the leaked refrigerant flows with the air and is likely to be discharged from the exhaust port 22a through the exhaust duct 22. Here, the showcase 1 is often installed adjacent to a wall or the like in a store, and the gap formed between the store wall and the rear panel 16 is likely to be narrow. Therefore, when the leaked refrigerant is discharged from the exhaust port 22a, the refrigerant is heavier than air and therefore tends to flow downward through the gap without being dispersed along the rear panel 16, which has been found to be a risk of the leaked refrigerant accumulating near the lower rear surface of the showcase 1. In contrast, in this embodiment, air inside the machine room 11 flows out through the rear port 16a. Therefore, even if the leaked refrigerant moves near the lower rear surface of the showcase 1, it is likely to be dispersed by the air flowing backward from the rear port 16a. This prevents a high concentration of leaked refrigerant from forming near the showcase 1, which is outside the showcase 1.

[0039] Furthermore, if refrigerant leaks from the pipe joint 34a of the evaporator 34, the leaked refrigerant moves through the cool air duct 7 together with the cool air. The refrigerant moving with the cool air leaks into the display chamber 8 through the outlet of the duct plate 6, for example. At this time, the pipe joint 34a, which is the source of the leaked refrigerant, is located to the left of the left-right center line L0 of the showcase 1 (see FIG. 4). Therefore, the refrigerant is likely to leak into the display chamber 8 biased to the left of the left-right center line L0. In particular, when the front opening 8a is blocked by the night cover 10, most of the leaked refrigerant flows out through the gap S (see FIG. 1) between the night cover 10 and the side panel 3. This makes it easy for the leaked refrigerant to become highly concentrated in the outflowing air, and it has been found that there is a risk that the highly concentrated leaked refrigerant may move to the front of the left side panel 14. In contrast to this, in the present embodiment, air flows out to the left from the machine chamber 11 through the side hole 14a, so that the leaking refrigerant that has moved to the vicinity of the lower front part of the left side surface of the showcase 1 is easily diffused by the air flowing out to the outside left of the showcase 1 through the side hole 14a. Therefore, it is possible to prevent an area with a high concentration of leaking refrigerant from being formed near the showcase 1.

[0040] Fig. 8 is a diagram showing the relationship between refrigerant concentration C near the lower back surface of showcase 1 in embodiment 1 and a showcase in a comparative example, and time T. Fig. 9 is a diagram showing the relationship between refrigerant concentration C near the lower front surface of the left side surface of showcase 1 in embodiment 1 and a showcase in a comparative example, and time T. In Figs. 8 and 9, the solid line indicates the change over time in showcase 1 in embodiment 1, and the dashed line indicates the change over time in the showcase in the comparative example. In the showcase 1 of the first embodiment and a comparative showcase that does not have the side hole 14a and the rear hole 16a, the relationship between the time T that has elapsed since a predetermined amount of refrigerant leaked from the pipe joints 32a, 34a and the refrigerant concentration C near the lower rear surface and the lower front left side surface was measured. The refrigerant concentration C is the concentration of the leaked refrigerant in the air.

[0041] As shown in Figure 8, when refrigerant leaks from the pipe joint 32a of the condenser 32, it was confirmed that the leaked refrigerant accumulates at the bottom of the back surface of the showcase 1. In this case, in the showcase of the comparative example, the concentration approaches the predetermined concentration C0 based on the lower flammability limit, and after time has passed, the leaked refrigerant diffuses and the concentration decays. In contrast, in the showcase 1 of the present embodiment, which is provided with the back hole 16a, the concentration only rises to a low value far short of the predetermined concentration C0, and it was confirmed that the concentration decreases more quickly than in the comparative example.

[0042] 9, when refrigerant leaks from the pipe joint 34a of the evaporator 34, it was confirmed that the leaked refrigerant accumulates near the lower front of the left side of the showcase 1 when the night cover 10 is in place. In this case, in the showcase of the comparative example, the concentration exceeds the predetermined concentration C0, and then diffuses and attenuates. In contrast, in the showcase 1 of the present embodiment, which is provided with the side hole 14a, it was confirmed that the concentration only rises to a low value that does not reach the predetermined concentration C0, and the concentration decreases more quickly than in the comparative example.

[0043] Therefore, in the showcase 1 of this embodiment, when a refrigerant leaks, it is possible to prevent the formation of a spatial region in the vicinity of the showcase 1 where the concentration of the leaking refrigerant is close to the lower flammability limit. Therefore, even if a refrigerant leaks from a showcase 1 that uses a flammable or slightly flammable refrigerant, the refrigerant concentration around the showcase 1 can be easily prevented from reaching the lower flammability limit (LFL). In particular, the showcase 1 is installed in a store such as a supermarket or convenience store, where ignition sources such as power outlets are likely to be present, posing a risk of ignition of the leaked refrigerant. However, the configuration of this embodiment makes it easy to prevent the formation of an area where the lower flammability limit is reached near the showcase 1, thereby effectively preventing ignition of the leaked refrigerant. The lower flammability limit is the minimum concentration of refrigerant that can propagate a flame when the refrigerant and air are uniformly mixed, as defined by ISO 817.

[0044] [1-3. Effects, etc.] As described above, in this embodiment, the showcase 1 comprises a housing 1a, a machine room 11 provided in the housing 1a, and a display room 8 provided in the housing 1a with an open front, and the housing 1a is formed with an air intake port 13a for introducing air into the machine room 11 and an exhaust port 22a for exhausting air from the machine room 11, the exhaust port 22a being formed in the upper part of the housing 1a, and a rear hole 16a communicating with the machine room 11 being formed in the lower part of the rear of the housing 1a. This allows a portion of the air in the machine chamber 11 to flow out through the rear hole 16a, generating an airflow near the lower rear surface of the showcase 1. Therefore, even if leaking refrigerant moves near the lower rear surface of the showcase 1, the airflow can diffuse the leaking refrigerant, preventing it from accumulating. Therefore, it is possible to provide a showcase 1 that prevents leaking refrigerant from accumulating near the showcase 1.

[0045] As in this embodiment, the machine room 11 may be provided below the display room 8, and the housing 1a may be provided with an exhaust duct 22 extending from the machine room 11 toward the exhaust port 22a. With this, even if the machine room 11 is provided at the bottom of the showcase 1, the air inside the machine room 11 can be exhausted from above through the exhaust duct 22 extending upward. Also, since most of the air introduced into the machine room 11 through the intake port 13a rises from the machine room 11 toward the exhaust port 22a at the top of the housing 1a, the internal pressure inside the machine room 11 tends to increase moderately, and this increased internal pressure can be used to easily allow an appropriate amount of air to flow out from the rear hole 16a. This makes it possible to prevent leaked refrigerant from accumulating near the showcase 1.

[0046] As in this embodiment, the lower end of the rear hole 16a may be provided at a position higher than the bottom panel 12 of the machine room 11. According to this, the rear hole 16a communicating with the outside is positioned higher than the bottom panel 12 where refrigerant leaking inside the machine chamber 11 is likely to accumulate. Therefore, it is possible to prevent refrigerant leaking inside the machine chamber 11 from leaking directly to the outside through the rear hole 16a. Therefore, it is possible to make it difficult for heavy leaking refrigerant to flow out while making it easier for light air to flow out, and it is possible to diffuse leaking refrigerant near the showcase 1 while preventing the leaking refrigerant from flowing out of the machine chamber 11.

[0047] (Other embodiments) As described above, the above-mentioned first embodiment has been described as an example disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the above-mentioned first embodiment to create new embodiments. Therefore, other embodiments will be exemplified below.

[0048] In the first embodiment, the rear holes 16a are configured to be formed in a row at the lower end of the rear surface, but the position and shape of the rear holes 16a can be any shape as long as they can efficiently exhaust air and accurately diffuse the refrigerant.

[0049] In the first embodiment, the side holes 14a are configured to be formed in two rows, one above the other and one behind the other, at the front lower portion of the side surface. However, the position and shape of the side holes 14a can be any shape as long as they can efficiently exhaust air and accurately diffuse the refrigerant.

[0050] In the first embodiment, the configuration in which the machine room 11 is provided below the display room 8 has been described, but the machine room may be located above the display room. In this case, a duct extending from the machine room to the rear hole 16a may be provided to allow air from the machine room to flow out from the rear hole 16a.

[0051] In the first embodiment, the configuration of the showcase 1 equipped with the night cover 10 has been described, but the showcase may be an open showcase not equipped with the night cover 10.

[0052] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0053] (Addendum) The above description of the embodiments discloses the following techniques.

[0054] (Technology 1) A showcase comprising a housing, a machine chamber provided in the housing, and a display chamber provided in the housing with an open front, wherein the housing is formed with an air intake port for introducing air into the machine chamber and an exhaust port for discharging air from the machine chamber, the exhaust port being formed in the upper part of the housing, and a rear hole communicating with the machine chamber being formed in the lower part of the rear of the housing. This allows a portion of the air in the machine chamber to flow out through the rear hole, generating an airflow near the lower rear surface of the showcase. Therefore, even if leaking refrigerant moves near the lower rear surface of the showcase, the airflow can diffuse the leaking refrigerant and prevent it from accumulating. Therefore, a showcase can be provided that prevents leaking refrigerant from accumulating near the showcase.

[0055] (Technology 2) The showcase according to Technology 1, wherein the machine room is provided below the display room, and the housing is provided with an exhaust duct extending from the machine room toward the exhaust port. This allows the air in the machine chamber to be exhausted from above through the exhaust duct, even if the machine chamber is located at the bottom of the showcase. Furthermore, because most of the air introduced into the machine chamber through the air intake rises from the machine chamber toward the exhaust port at the top of the housing, the internal pressure in the machine chamber can be easily increased. This increased internal pressure can be used to easily allow an appropriate amount of air to flow out through the rear opening. This prevents refrigerant leaks from accumulating near the showcase.

[0056] (Technical Aspect 3) The showcase according to Technical Aspect 2, wherein the lower end of the rear hole is provided at a position higher than the inner bottom surface of the machine chamber. This configuration places the rear hole, which is connected to the outside, higher than the inner bottom surface where refrigerant leaking into the machine chamber tends to accumulate, thereby preventing refrigerant leaking into the machine chamber from leaking directly to the outside through the rear hole. [Industrial Applicability]

[0057] The present disclosure is applicable to a refrigerated or frozen showcase for displaying products, and more specifically, to a showcase that uses a flammable or slightly flammable refrigerant. [Explanation of symbols]

[0058] 1. Showcase 1a Housing 2. Insulated walls 3 Side Panel 4 Main unit 6 Duct plate 7. Cold air duct 7a Cool air outlet 7b Cold air intake 8 Exhibition room 8a Front opening 8b Engagement part 9. Cold air intake member 10 Night Cover 10a Engagement member 11 Machine room 12 Bottom panel (inner bottom) 13 Front panel (front) 13a Air intake 14 Side panel (side) 14a Side hole 15 Side Panel 16 Rear panel (rear) 16a Back hole 17 Upper Front Panel 18 Top panel 21 Drain pipe 22 Exhaust duct 22a Exhaust port 23 Shelf device (shelf board) 24 Posts 31 Compressor 32 Condenser 32a Piping joint 34 Evaporator (heat exchanger) 34a Piping joint 35 Refrigerant piping 35a Evaporation pipe 36 Refrigerant piping 37 Condenser fan 38 Cool air blower 41 Evaporation unit 42 Evaporating dish 43 Evaporation Paper 44 Evaporation Unit 45 Evaporating dish 46 Evaporation Paper 47 Evaporation fan 48 Electrical box 49 Electrical box 51 U-shaped pipe (piping) 52 Finn 53 Connection piping (piping) A1 intake formation area C Refrigerant concentration C0 predetermined concentration L0 Left and right center line L1 Front-rear center line S Gap S1 designated space T time

Claims

1. A showcase comprising a housing, a machine chamber provided in the housing, and a display chamber provided in the housing with an open front, The housing is formed with an intake port for introducing air into the machine chamber and an exhaust port for discharging air from the machine chamber, the exhaust port is formed in an upper portion of the housing, A rear hole communicating with the machine chamber is formed in the lower part of the rear surface of the housing. Showcase.

2. The machine room is provided below the display room, The housing is provided with an exhaust duct extending from the machine chamber toward the exhaust port. The showcase according to claim 1.

3. The lower end of the rear hole is located at a position higher than the inner bottom surface of the machine room. The showcase according to claim 2.

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