Cooling device

Abstract

To provide a cooling device which can defrost an evaporator while suppressing a rise of a temperature of a cooling space.SOLUTION: A cooling device 100 comprises evaporators (41, 42) (first evaporators) and evaporators (43, 44) (second evaporators). Also, the cooling device 100 includes a cooling flow passage 71 (first cooling flow passage) of air which is sent to the evaporators (41, 42) from blowers (51, 52) (inside blowers), and blown out of a blowout port 61 (first blowout port), and a cooling flow passage 72 (second cooling flow passage) of air which is sent to the evaporators (43, 44) from blowers (53, 54), and blown out of a blowout port 62 (second blowout port). The cooling device further comprises a multilayer flow passage part 70 for multi-laying airflows in the device. The cooling device 100 is constituted so as to be switchable in cooling operations and defrosting operations of the evaporators (41, 42) and the evaporators (43, 44).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a cooling device, and more particularly to a cooling device including an evaporator. [Background technology]

[0002] 2. Description of the Related Art Conventionally, cooling devices equipped with an evaporator are known (see, for example, Patent Document 1).

[0003] The cooler (cooling device) described in the above Patent Document 1 includes a heat exchanger (evaporator) that includes a flow path therein for passing a refrigerant. The cooler also includes a blower fan that blows air to remove frost adhering to the heat transfer surface of the heat exchanger. When defrosting the cooler, the blower fan rotates in a predetermined direction to blow air to the heat exchanger and remove the frost adhering to the heat exchanger. The frost removed from the heat exchanger is sent to a discharge mechanism below the heat exchanger. When cooling the cooler, the blower fan is rotated in the opposite direction to when defrosting, generating an airflow directed upward. At this time, the air (airflow) that has come into contact with the heat exchanger and been cooled is blown out of the cabinet from the upper side. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-96592 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the cooler (cooling device) described in Patent Document 1, the air flow path is common during cooling and defrosting, so the cooling operation needs to be stopped during defrosting. This may cause the temperature outside the cabinet (cooling space) to rise during defrosting. Therefore, there is a demand for a cooling device that can defrost the heat exchanger (evaporator) while suppressing the temperature rise in the cooling space.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a cooling device that is capable of defrosting an evaporator while suppressing an increase in temperature in the cooling space. [Means for solving the problem]

[0007] A cooling device including a compressor that compresses a refrigerant, a condenser that condenses the refrigerant discharged from the compressor, and an expansion section that expands the refrigerant condensed by the condenser, a first evaporator and a second evaporator for evaporating the refrigerant expanded by the expansion section; the cooling operation and the defrosting operation of each of the first evaporator and the second evaporator are switched, the first cooling flow path includes an inner flow path that is arranged along the cooling space and connected to the first outlet and in which the first evaporator is arranged, the second cooling flow path includes an outer flow path that is arranged along the inner flow path on the opposite side to the cooling space with respect to the inner flow path and connected to the second outlet and in which the second evaporator is arranged, and in an operating state in which the first evaporator arranged in the inner flow path is operated in a defrosting operation while the second evaporator arranged in the outer flow path is operated in a cooling operation, the frost attached to the first evaporator arranged in the inner flow path is removed by wind pressure using the air sucked in from the first outlet, an inner defrosting operation in which the air cooled by the second evaporator is blown out from the second blowing outlet and the inner blowing outlet is rotated forward while the first evaporator is in a cooling operation, thereby forming an air curtain that isolates the cooling space from the outside air, the first blowing outlet forms a first air curtain that isolates the cooling space from the outside air by blowing out air flowing through a first cooling flow path, and the second blowing outlet forms a second air curtain that isolates the cooling space from the outside air by blowing out air flowing through a second cooling flow path, the inner defrosting operation in which the air cooled by the second evaporator is blown out from the second blowing outlet by rotating the outer blower forward while the first evaporator is in a defrosting operation, thereby removing frost attached to the first evaporator by air sucked in from the first blowing outlet by wind pressure, The first evaporator is operated in a cooling operation while the inside blower is rotated in the normal direction, so that the air cooled by the first evaporator is blown out from the first outlet to form a first air curtain, and an outside defrosting operation is performed by operating the second evaporator in a defrosting operation at a temperature at which frost melts while rotating the outside blower in the normal direction or at a stop, so that switching is possible. .

[0008] In the cooling device according to one aspect of the present invention, as described above, a multilayer flow path portion including a first cooling flow path and a second cooling flow path is provided, and the cooling operation and the defrosting operation of each of the first evaporator and the second evaporator are configured to be switched. As a result, by performing a cooling operation of the first evaporator and a defrosting operation of the second evaporator, it is possible to defrost the second evaporator while continuing cooling using the first cooling flow path. Also, by performing a defrosting operation of the first evaporator while performing a cooling operation of the second evaporator, it is possible to defrost the first evaporator while continuing cooling using the second cooling flow path by switching between the cooling operation and the defrosting operation. As a result, it is possible to defrost the evaporators (the first evaporator and the second evaporator) while suppressing the temperature of the cooling space from rising. In addition, the air is blown out from each of the first and second air outlets to form an air curtain that blocks the cooling space from outside air, and thus the formation of the air curtain can prevent outside air from flowing into the cooling space, thereby preventing the temperature in the cooling space from rising. As a result, the cooling operation and defrosting operation of each of the first and second evaporators are switched to prevent the formation (blowing) of the air curtain from being stopped at both the first and second air outlets. This allows the evaporators (the first and second evaporators) to be defrosted while preventing the temperature in the cooling space from rising due to the formation of the air curtain being stopped. In addition, the first air outlet is configured to blow out air flowing through the first cooling flow path to form a first air curtain that blocks the cooling space from outside air, and the second air outlet is configured to blow out air flowing through the second cooling flow path to form a second air curtain that blocks the cooling space from outside air, so that the first evaporator and the second evaporator are switched between cooling operation and defrosting operation, respectively, to prevent the formation (blowing) of both the first air curtain and the second air curtain from being stopped. As a result, the evaporators (the first evaporator and the second evaporator) can be defrosted while suppressing a rise in the temperature of the cooling space caused by the formation of both the first air curtain and the second air curtain being stopped.The blower includes an inner blower for circulating air through the inner flow path and an outer blower for circulating air through the outer flow path, and performs an inner defrosting operation in which the air cooled by the second evaporator is blown out from the second outlet by rotating the outer blower in the forward direction while performing a cooling operation of the second evaporator to form a second air curtain, and the inner blower is rotated in the reverse direction while performing a defrosting operation of the first evaporator to remove frost adhering to the first evaporator by air pressure sucked in from the first outlet, and the first evaporator is operated in the cooling operation. The inside defrosting operation is configured to rotate the inside blower in the normal direction while rotating the inside blower in the normal direction, so that the air cooled by the first evaporator is blown out from the first outlet to form a first air curtain, and the outside defrosting operation is configured to rotate the outside blower in the normal direction or stop while performing a defrosting operation on the second evaporator at a temperature at which frost melts. In this way, during the inside defrosting operation, the temperature of the air that has defrosted the first evaporator can be made relatively low by performing wind pressure defrosting on the first evaporator, compared to when melting and defrosting is performed on the first evaporator. As a result, even if the air that has defrosted the first evaporator flows into the second cooling flow path, it is possible to prevent the temperature of the air flowing through the second cooling flow path (the temperature of the second air curtain) from becoming high. In addition, during the outside defrosting operation, the melting and defrosting is performed on the second evaporator, so that the defrosting of the second evaporator can be made relatively quickly, compared to when wind pressure defrosting is performed on the second evaporator. In addition, during the outer defrosting operation, the first air curtain is formed by the air flowing through the inner flow passage, and the first air curtain can prevent the air (second air curtain) that has been melted and defrosted and heated from flowing into the cooling space. Therefore, during the outer defrosting operation, the second evaporator can be defrosted relatively quickly while preventing the temperature in the cooling space from rising.

[0012] In a configuration in which the first air outlet blows out air flowing through a first cooling flow path to form a first air curtain, and the second air outlet blows out air flowing through a second cooling flow path to form a second air curtain, Preferably, the first air curtain and the second air curtain are formed by blowing air out of the first air outlet and the second air outlet, respectively. With this configuration, it is possible to more reliably prevent outside air from entering the cooling space, compared to a case in which only one of the first air curtain and the second air curtain is formed.

[0013] the above The first air outlet blows out air flowing through the first cooling passage to form a first air curtain, and the second air outlet blows out air flowing through the second cooling passage to form a second air curtain. In the cooling space, preferably, an opening is provided on a side surface of the cooling space between the bottom surface of the cooling space on which the product is placed and the upper end of the cooling space, to communicate the inner flow path with the cooling space. With this configuration, when the cooling air (first air curtain) is blown out from the first air outlet, the cooling air flows out of the inner flow path into the cooling space through the opening, so that the temperature of the cooling space can be more reliably prevented from rising. Also, when air is sucked in from the first air outlet and the cooling air (second air curtain) is blown out from the second air outlet, a part of the air in the cooling space is sucked into the inner flow path through the opening, so that the air in the cooling space can be more efficiently sucked into the inner flow path. As a result, the generation of an air vortex in the cooling space can be suppressed, and the bending of the second air curtain due to the generation of the vortex can be suppressed.

[0014] the above The first air outlet blows out air flowing through the first cooling passage to form a first air curtain, and the second air outlet blows out air flowing through the second cooling passage to form a second air curtain. In the above, preferably, the width of the second air outlet is larger than the width of the first air outlet in the direction in which the first air outlet and the second air outlet are aligned. With this configuration, the speed of the air blown out from the second air outlet can be reduced compared to when the width of the second air outlet is equal to or smaller than the width of the first air outlet. As a result, it is possible to suppress the formation of a vortex caused by the high speed of the air blown out from the second air outlet. As a result, it is possible to suppress the air forming the vortex from flowing in a manner that expands toward the second air curtain, and it is also possible to suppress the second air curtain from being curved by the air flowing in a manner that expands toward the second air curtain.

[0016] the above The first air outlet forms a first air curtain by blowing out air flowing through the first cooling flow path, and the second air outlet forms a second air curtain by blowing out air flowing through the second cooling flow path. In the above, preferably, the first evaporator and the second evaporator are arranged side by side in a direction intersecting the air flow direction, and further include a first windshield plate provided on the inner flow path side of the first evaporator and extending intersecting the air flow direction so as to block a part of the first cooling flow path, and a second windshield plate provided on the outer flow path side of the second evaporator and extending intersecting the air flow direction so as to block a part of the second cooling flow path. With this configuration, the air flow can be made to meander when the air passes through each of the first windshield plate and the second windshield plate. As a result, the direction of at least a part of the air flow can be changed more easily than when the air moves straight without the first windshield plate and the second windshield plate. This makes it possible to easily diffuse the air in the direction in which the first evaporator and the second evaporator are arranged, and therefore it is possible to suppress the wind speed distribution in the direction in which the first evaporator and the second evaporator are arranged from becoming uneven. As a result, it is possible to suppress the occurrence of unevenness in temperature depending on the position in the cooling space. Effect of the Invention

[0017] According to the present invention, as described above, it is possible to defrost the evaporator while suppressing an increase in temperature in the cooling space. [Brief description of the drawings]

[0018] [Figure 1] 1 is a block diagram showing a configuration of a cooling device according to an embodiment; [Diagram 2] FIG. 2 is a perspective view illustrating an evaporator of the cooling device according to the embodiment. [Diagram 3] 1 is a cross-sectional view perpendicular to the Y direction showing the configuration of a cooling device according to an embodiment. [Figure 4] 2 is a cross-sectional view (a cross-sectional view taken along line 200-200 in FIG. 3) perpendicular to the Z direction, showing the configuration of a cooling device according to an embodiment. [Diagram 5] 4 is a cross-sectional view perpendicular to the Y direction showing an air flow during an inside defrosting operation of a cooling device according to an embodiment. FIG. [Figure 6] 4 is a cross-sectional view perpendicular to the Z direction showing an air flow during an inside defrosting operation of the cooling device according to the embodiment. FIG. [Figure 7] 4 is a cross-sectional view perpendicular to the Y direction showing an air flow during an outer defrosting operation of a cooling device according to an embodiment. FIG. [Figure 8] 4 is a cross-sectional view perpendicular to the Z direction showing an air flow during an outer side defrosting operation of a cooling device according to an embodiment. FIG. [Figure 9] 8 is a partially enlarged view of the vicinity of the opening in FIG. 7. [Figure 10] FIG. 2 is a perspective view showing the configuration of an inner flow passage and an outer flow passage of a cooling device according to one embodiment. [Figure 11] 13 is an example of a simulation result showing a relationship between a width of an outlet port of an outer flow passage and a heat load. [Figure 12] 13 is an example of a simulation result showing a relationship between the position of an opening and a thermal load. [Figure 13] 13 is an example of a simulation result showing a cooling effect depending on the width and opening of the outlet of the outer flow passage. [Figure 14] 13 is an example of a simulation result showing the cooling effect of the cooling device according to an embodiment when the vehicle is fully loaded with products. [Figure 15]13 is an example of a simulation result showing the cooling effect of the cooling device according to one embodiment when about half the amount of products is placed in the cooling space as when the cooling space is fully loaded. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0020] [Present embodiment] The configuration of a cooling device 100 according to the present embodiment will be described with reference to FIGS.

[0021] The cooling device 100 is configured to cool the cooling space 110 (see FIG. 3). Specifically, the cooling device 100 is configured to cool the cooling space 110 to a temperature of 0° C. or lower. For example, the cooling device 100 is configured to cool the cooling space 110 to a temperature of about −20° C. The cooling device 100 is configured to cool the inside (interior) of a showcase, which serves as the cooling space 110.

[0022] As shown in Fig. 1, the cooling device 100 includes a compressor 10. The compressor 10 is configured to compress a refrigerant. The compressor 10 is controlled by an inverter (not shown). As a result, the compressor 10 is configured to be able to adjust the flow rate of the refrigerant discharged from the compressor 10. The refrigerant is, for example, R410A, R404A, R32, carbon dioxide (CO2), or the like.

[0023] The cooling device 100 also includes a condenser 20. The condenser 20 is configured to condense the refrigerant discharged from the compressor 10. The condenser 20 is provided with a blower 21. The blower 21 is configured to send air to the condenser 20. Then, heat is transferred from the refrigerant in the condenser 20 to the air sent by the blower 21.

[0024] The cooling device 100 also includes expansion valves 31, 32, 33, and 34. The expansion valves 31, 32, 33, and 34 are configured to expand the refrigerant condensed by the condenser 20. The expansion valves 31, 32, 33, and 34 are configured, for example, as needle valves. The openings of the expansion valves 31, 32, 33, and 34 are adjusted by stepping motors (not shown) attached to the expansion valves 31, 32, 33, and 34. The flow rates of the refrigerant to the evaporators 41, 42, 43, and 44 provided downstream of the expansion valves 31, 32, 33, and 34 are adjusted by adjusting the openings of the expansion valves 31, 32, 33, and 34. Each of the expansion valves 31 to 34 is an example of an "expansion unit" in the claims.

[0025] The cooling device 100 also includes evaporators 41, 42, 43, and 44. The evaporators 41, 42, 43, and 44 are configured to evaporate the refrigerant expanded by the expansion valves 31, 32, 33, and 34, respectively. The evaporators 41 to 44 are provided in parallel to one another. As shown in FIG. 2, the evaporators 41, 42, 43, and 44 each include a refrigerant flow path through which the refrigerant flows, and a heat transfer surface 41a that transfers the temperature of the refrigerant. Specifically, the evaporators 41, 42, 43, and 44 each include a plurality of flat plates arranged in parallel to one another. The flat plates are made of a metal such as aluminum. The front and back surfaces of the flat plates are the heat transfer surfaces 41a. The refrigerant flow path penetrates the plurality of flat plates and is provided in a meandering manner. The heat transfer surface 41a may be flat or may have an uneven shape. By having the heat transfer surface 41a have an uneven shape, it is possible to easily remove the frost that has adhered thereto. Each of the evaporators 41 and 42 is an example of a "first evaporator" in the claims, and each of the evaporators 43 and 44 is an example of a "second evaporator" in the claims.

[0026] As shown in FIG. 1, the cooling device 100 includes a blower 51 that sends air to the evaporator 41, and a blower 52 that sends air to the evaporator 42. The cooling device 100 also includes a blower 53 that sends air to the evaporator 43, and a blower 54 that sends air to the evaporator 44. Each of the blowers 51 and 52 is provided to circulate air through an inner flow path 71a described below. Each of the blowers 53 and 54 is provided to circulate air through an outer flow path 72a described below. Each of the blowers 51 and 52 is an example of an "inner blower" in the claims. Each of the blowers 53 and 54 is an example of an "outer blower" in the claims.

[0027] 3, the cooling device 100 is provided with an air outlet 61 and an air outlet 62 for blowing out air. The cooling device 100 is also provided with an intake port 63 for sucking in the air blown out from the air outlet 61 and the air outlet 62. The air outlet 61 and the air outlet 62 are examples of the "first air outlet" and the "second air outlet" in the claims, respectively.

[0028] Here, in this embodiment, the cooling device 100 is configured to form air curtains (E1, E2) that block the cooling space 110 from the outside air by blowing out air from each of the air outlet 61 and the air outlet 62. Specifically, the air outlet 61 blows out air flowing through a cooling flow path 71 described later, thereby forming an air curtain E1 (see FIG. 7) that blocks the cooling space 110 from the outside air. The air outlet 62 is configured to blow out air flowing through a cooling flow path 72 described later, thereby forming an air curtain E2 (see FIG. 5) that blocks the cooling space 110 from the outside air. The air curtains E1 and E2 are examples of a "first air curtain" and a "second air curtain" in the claims, respectively.

[0029] Specifically, each of the air curtains E1 and E2 flows horizontally toward the X1 direction, thereby preventing outside air from entering the cooling space 110 below the air curtains E1 and E2 (on the Z2 direction side).

[0030] In this embodiment, the cooling device 100 is configured to form two-layered air curtains E1 and E2 by blowing air out from each of the air outlets 61 and 62. Specifically, both the air curtains E1 and E2 are formed during an outside defrosting operation (see FIG. 7) described later. As a result, the air curtains E1 and E2 are two-layered. At this time, the air curtain E1 flows on the cooling space 110 side (Z2 direction side), and the air curtain E2 flows on the opposite side of the air curtain E1 from the cooling space 110 (Z1 direction side).

[0031] 3, the cooling device 100 includes a multilayer flow path section 70 that multilayers the airflow inside the cooling device 100. The multilayer flow path section 70 includes a cooling flow path 71 for air sent from the blowers (51, 52) to the evaporators (41, 42) and blown out from the outlet 61. The multilayer flow path section 70 also includes a cooling flow path 72 for air sent from the blowers (53, 54) to the evaporators (43, 44) and blown out from the outlet 62. The cooling flow path 71 and the cooling flow path 72 are examples of a "first cooling flow path" and a "second cooling flow path" in the claims, respectively.

[0032] Here, in this embodiment, the cooling flow path 71 includes an inner flow path 71a that is disposed along the cooling space 110 and is connected to the air outlet 61. The cooling flow path 72 includes an outer flow path 72a that is disposed along the inner flow path 71a on the opposite side of the cooling space 110 with respect to the inner flow path 71a and is connected to the air outlet 62. In a cross-sectional view perpendicular to the Y direction (cross-sectional view shown in FIG. 3), each of the inner flow path 71a and the outer flow path 72a has a substantially U-shape in which a lower end side (Z2 side) and an upper end side (Z1 side) extend in the horizontal direction and a portion between the lower end side and the upper end side extends in the vertical direction (Z direction).

[0033] The cooling device 100 is also provided with a partition wall 81 that separates the inner flow passage 71a and the outer flow passage 72a (which are adjacent to each other in the X direction). The cooling device 100 also includes a partition wall 82 that separates a flow passage 71c (to be described later) from a flow passage 72b (to be described later).

[0034] 4, the cooling flow passage 71 includes a flow passage 71b and a flow passage 71c. Each of the flow passages 71b and 71c is connected to the inner flow passage 71a. The flow passage 71b is provided with an evaporator 41 and a blower 51. The flow passage 71c is provided with an evaporator 42 and a blower 52. The flow passages 71b and 71c are separated by a partition wall 83.

[0035] The cooling passage 72 includes a passage 72b and a passage 72c. Each of the passages 72b and 72c is connected to the outer passage 72a. The passage 72b is provided with an evaporator 43 and a blower 53. The passage 72c is provided with an evaporator 44 and a blower 54. The passages 72b and 72c are separated by a partition wall 84.

[0036] Only one flow path (shared by each of the fans) is provided between the suction port 63 and the fans (51-54).

[0037] In a cross-sectional view perpendicular to the Z direction (cross-sectional view shown in FIG. 4), the inner flow passage 71a is configured such that the flow passage width changes across the step portion 71d. In the X direction, the width of the inner flow passage 71a on the evaporator (41, 42) side of the step portion 71d is W1. In the X direction, the width of the inner flow passage 71a on the opposite side of the step portion 71d to the evaporator (41, 42) is W2, which is larger than W1.

[0038] In a cross-sectional view perpendicular to the Z direction (cross-sectional view shown in FIG. 4), the outer flow passage 72a is configured such that the flow passage width changes at the step portion 72d. In the X direction, the width of the outer flow passage 72a on the evaporator (43, 44) side of the step portion 72d is W3. In the X direction, the width of the outer flow passage 72a on the opposite side of the step portion 72d from the evaporator (43, 44) is W2, which is larger than W3. Note that the width W1 and the width W3 are approximately equal.

[0039] In this embodiment, the cooling device 100 is configured to switch between a cooling operation and a defrosting operation of each of the evaporators (41, 42) and (43, 44). Specifically, one of the evaporators (41, 42) and (43, 44) is set to a cooling operation state, and the other of the evaporators (41, 42) and (43, 44) is set to a defrosting operation state. The operation state of the evaporators (41-44) (temperature control of each evaporator) is controlled by the control unit 1 (see FIG. 1). The control unit 1 is also configured to be able to control the blowing direction and air volume of the fans 51-54.

[0040] In detail, as shown in Fig. 5 and Fig. 6, in the cooling device 100, the evaporators (43, 44) are operated in a cooling operation and the blowers (53, 54) are rotated in the forward direction, so that the air cooled by the evaporators (43, 44) is blown out from the outlet 62 to form an air curtain E2, and the evaporators (41, 42) are operated in a defrosting operation and the blowers (51, 52) are rotated in the reverse direction, so that the air sucked in from the outlet 61 removes frost adhering to the evaporators (41, 42) by wind pressure, thereby performing an inside defrosting operation. That is, during the inside defrosting operation, the air curtain E1 is not formed, and only the air curtain E2 is formed. During the inside defrosting operation, the blowers (51, 52) are rotated in the reverse direction, so that the air warmed by the defrosting is prevented from flowing out directly into the cooling space 110.

[0041] Then, the wind pressure of the air sucked through the air outlet 61 blows off frost from the heat transfer surface 41a of the evaporator (41, 42). The blown off frost is blown into the cooling flow passage 72 by the air blown by the blowers (53, 54) of the cooling flow passage 72, and is collected by the evaporator (43, 44). At this time, the air heated by defrosting the evaporator (43, 44) is cooled in the evaporator (41, 42) and flows out again into the cooling space 110. At this time, the air heated by defrosting the evaporator (43, 44) flows out again into the cooling space 110 without circulating inside the device, so that the temperature of the air that has defrosted the evaporator (43, 44) is prevented from increasing. As a result, it is possible to prevent the temperature of the cooling space 110 from increasing.

[0042] During the inside defrosting operation, the temperature of the evaporators (43, 44) is maintained at approximately −35° C., and the temperature of the evaporators (41, 42) is maintained at approximately 0° C. In addition, the airflow rate of the fans (51, 52) is set to be equal to or lower than the airflow rate of the fans (53, 54).

[0043] 7 and 8, in the cooling device 100, the air cooled by the evaporators (41, 42) is blown out from the air outlet 61 to form an air curtain E1 by rotating the fans (51, 52) in the forward direction while the evaporators (41, 42) are in cooling operation, and an outside defrosting operation is performed in which the fans (53, 54) are rotated in the forward direction while the evaporators (43, 44) are in defrosting operation at a temperature at which frost melts. Specifically, during the outside defrosting operation, the temperatures of the evaporators (41, 42) are maintained at approximately -35°C, and the temperatures of the evaporators (43, 44) are maintained at approximately 10°C. The airflow rates of the fans (53, 54) are set to be equal to or lower than the airflow rates of the fans (51, 52).

[0044] During the outer defrosting operation, air is blown out from each of the air outlets 61 and 62, so that two-layered air curtains E1 and E2 are formed. At this time, the air curtain E1 made of cooled air is formed closer to the cooling space 110 than the air curtain E2, so that the cooling space 110 is prevented from being heated by the air curtain E2, which has a relatively high temperature.

[0045] The cooling device 100 is configured to switch between an inside defrosting operation and an outside defrosting operation. Specifically, the inside defrosting operation and the outside defrosting operation are configured to switch at predetermined time intervals. The time of the inside defrosting operation and the time of the outside defrosting operation may be set to be equal, or one of the times may be longer than the other. Switching between the inside defrosting operation and the outside defrosting operation is performed by the control unit 1 (see FIG. 1).

[0046] Further, a drain outlet 120a is provided on the bottom surface 120 on which the evaporators (41-44) are placed. The drain outlet 120a is provided to discharge frost melted in the evaporators (43, 44) during the outside defrosting operation. Further, the bottom surface 120 on which the evaporators (41-44) are placed is provided so as to incline downward toward the drain outlet 120a. This allows moisture generated by melting the frost to move toward the drain outlet 120a. For simplification, the drain outlet 120a is not shown in FIGS. 4, 6, and 8.

[0047] 9, the cooling device 100 is provided with a bottom surface 110a of the cooling space 110 on which the product 130 is placed. The cooling device 100 is also provided with a side surface 110c disposed between the bottom surface 110a of the cooling space 110 and an upper end portion 110b of the cooling space 110. The side surface 110c is a surface sandwiched in the up-down direction (Z direction) between the air outlet 61 (air outlet 62) and the bottom surface 110a.

[0048] In this embodiment, an opening 110d that connects the inner flow passage 71a and the cooling space 110 is provided on the side surface 110c of the cooling space 110. The opening 110d is a rectangular hole as shown in Fig. 10. A plurality of openings 110d are arranged side by side along the Y direction. Note that Fig. 10 is an example, and the number and shape of the openings 110d are not limited thereto.

[0049] 9, the opening 110d is provided at a position where the length in the Z direction between the lower end of the opening 110d and the bottom surface 110a of the cooling space 110 is L1 (for example, 60 mm). The length in the Z direction of the cooling space 110 (side surface 110c) is L2 (for example, 420 mm). The width in the Z direction of the opening 110d is W7 (for example, 30 mm). Note that the position and size of the opening 110d described above are merely examples and are not limited thereto.

[0050] During the inner defrosting operation (see FIG. 5), since the opening 110d is provided, the air in the cooling space 110 flows into the inner flow path 71a from each of the air outlet 61 and the opening 110d. As a result, the air in the cooling space 110 is more efficiently drawn into the inner flow path 71a than when the opening 110d is not provided. As a result, the generation of an air vortex in the cooling space 110 is suppressed, and the bending of the air curtain E2 due to the generation of the vortex is suppressed.

[0051] During the outer defrosting operation (see FIG. 7), since the opening 110d is provided, the cooling air flows out from the inner flow path 71a to the cooling space 110 via the opening 110d. This makes it possible to efficiently cool the cooling space 110. In particular, when the cooling air that flows out from the inner flow path 71a to the cooling space 110 via the opening 110d flows along the surface of the commodity 130 (see air E3 in FIG. 9) due to the Coanda effect (the phenomenon in which a fluid is attracted to a nearby wall), the cooling air is prevented from flowing out of the cooling space 110 to the outside, and the cooling effect becomes more pronounced.

[0052] Furthermore, in this embodiment, in the direction in which the air outlet 61 and the air outlet 62 are aligned (the Z direction in this embodiment), the width W4 of the air outlet 62 is larger than the width W5 of the air outlet 61. For example, the ratio (W4 / W6) of the width W4 to the width W6 in the Z direction of the air outlet (the entire air outlet including the air outlet 61 and the air outlet 62) is about 90%. This makes it possible to make the wind speed of the air blown out from the air outlet 62 relatively low. Note that the above ratio is an example and is not limited to this.

[0053] 3, the cooling device 100 includes a windshield 91 that is provided on the inner flow passage 71a side (X2 direction side) of the evaporator (41, 42) and extends intersecting the air flow direction (X direction) so as to block a part of the cooling flow passage 71. The cooling device 100 also includes a windshield 92 that is provided on the outer flow passage 72a side (X2 direction side) of the evaporator (43, 44) and extends intersecting the air flow direction (X direction) so as to block a part of the cooling flow passage 72. The windshield 91 and the windshield 92 are examples of a "first windshield" and a "second windshield" in the claims, respectively.

[0054] Specifically, as shown in FIG. 10, a gap C1 (see FIG. 7) is provided below the wind shielding plate 91 in the inner flow passage 71a. The wind shielding plate 91 is provided on the opposite side (X2 direction side) of the evaporator (41, 42) from the step portion 71d (see FIG. 4). That is, the wind shielding plate 91 is provided in the inner flow passage 71a at a location having a width W2 (see FIG. 4) in the Y direction. Therefore, the length L3 of the wind shielding plate 91 along the Y direction is approximately equal to the width W2. The wind shielding plate 91 is provided orthogonal to the X direction (extending in the YZ plane) so as to block the air flowing in the X2 direction in the inner flow passage 71a. Thus, the air flowing through the inner flow passage 71a flows so as to go under the gap C1 below the wind shielding plate 91 (see FIG. 7). As a result, the air is diffused in the Y direction due to the air meandering when passing through the wind shielding plate 91. This makes the wind speed distribution in the Y direction of the air flowing through the inner flow passage 71a uniform.

[0055] Further, in the outer flow passage 72a, a gap C2 (see FIG. 5) is provided below the wind shielding plate 92. The wind shielding plate 92 is provided on the opposite side (X2 direction side) of the evaporator (43, 44) from the step portion 72d. That is, the wind shielding plate 92 is provided in the outer flow passage 72a at a location having a width W2 (see FIG. 4) in the Y direction. Therefore, the length L4 of the wind shielding plate 92 along the Y direction is substantially equal to the width W2. The wind shielding plate 92 is provided orthogonal to the X direction (extending in the YZ plane) so as to block the air flowing in the X2 direction in the outer flow passage 72a. Thus, the air flowing through the outer flow passage 72a flows so as to go under the gap C2 below the wind shielding plate 92 (see FIG. 5). As a result, the air is diffused in the Y direction due to the air meandering when passing through the wind shielding plate 92. Thus, the wind speed distribution in the Y direction of the air flowing through the outer flow passage 72a becomes uniform.

[0056] 10, the inner flow path 71a includes an inlet 71e through which air sent from the fans (41, 42) is introduced. The outer flow path 72a includes an inlet 72e through which air sent from the fans (43, 44) is introduced. The inlet 71e is provided on the Y1 side and the Z1 side of the inlet 72e.

[0057] (Simulation results) Next, the results of a simulation of the cooling device 100 of this embodiment will be described with reference to FIGS.

[0058] FIG. 11 shows the heat load of the cooling device 100 when W4 / W6 (see FIG. 9), which is the ratio of the air outlet 62 to the entire air outlet, is changed.

[0059] The results showed that the thermal load was minimized when the ratio was 90% during the inside defrosting operation in both a state where the refrigerator was fully loaded with products 130 (see FIG. 9) and a state where about half the amount of products 130 as in the fully loaded state was placed in the cooling space 110. Note that the results in FIG. 11 are data obtained under the condition that the length L1 (see FIG. 9), which represents the height of the opening 110d, was 140 mm or less.

[0060] This is because the wind speed of the air curtain E2 (see FIG. 5) becomes relatively small as a result of the width W4 of the air outlet 62 becoming relatively large. This reduces the vorticity of the vortex V1 in the cooling space 110, and the air curtain E2 is prevented from being pulled downward (toward Z1). As a result, the air curtain E2 is prevented from curving. As a result, the outside air is prevented from flowing into the cooling space 110. The vorticity is an index that indicates the strength of the vortex.

[0061] During the outside defrosting operation, no significant correlation was found between the above ratio and the heat load.

[0062] Next, FIG. 12 shows the heat load when the length L1, which indicates the height of the opening 110d from the bottom surface portion 110a, is changed during the outside defrosting operation.

[0063] It was confirmed that when about half the amount of products 130 in the cooling space 110 is loaded, the thermal load on the cooling device 100 is smaller when the length L1 is 0 mm to 150 mm than when the length L1 is about 290 mm. This is because when the length L1 is small, the opening 110d is positioned to overlap with the products 130, making the Coanda effect described above more likely to occur.

[0064] During the outer defrosting operation, vortex V2 (see FIG. 7) is formed by the air flowing out from the opening 110d. In addition to vortex V2, vortex V3 (see FIG. 7) is formed above vortex V2, and vortex V4 (see FIG. 7) is formed on the suction port 63 side (X1 side) with respect to vortex V2 and vortex V3. These vortices (V2 to V4) push up the air curtain E1, forcing the air curtain E1 to move straight without curving downward. This prevents outside air from flowing into the cooling space 110.

[0065] Next, FIG. 13 shows the results of the cooling effect according to the opening 110d and the width W4 of the air outlet 62 during the inside defrosting operation.

[0066] As shown in FIG. 13, in a state (comparative example) where the opening 110d is not provided and the width W4 of the air outlet 62 is not adjusted (i.e., W4 / W6=0.5), the temperature of the cooling space 110 was −12.1° C. In addition, in a state where the opening 110d is provided and the width W4 is not adjusted (W4 / W6=0.5), the temperature of the cooling space 110 was −14.1° C. In addition, in a state where the opening 110d is not provided and the width W4 is adjusted (i.e., W4 / W6=0.9), the temperature of the cooling space 110 was −18.2° C. From these results, it was found that the opening 110d and the adjustment of the width W4 of the air outlet 62 each contribute to the cooling effect. This is because the adjustment of the opening 110d and the width W4 of the air outlet 62 suppresses the air curtain E2 from bending.

[0067] Next, Figures 14 and 15 show the results of the cooling effect of cooling device 100 during inside defrosting operation and outside defrosting operation, respectively. Figure 14 shows the results when the refrigerator is fully loaded with products 130. As shown in Figure 14, it was found that the air temperature in cooling space 110, the temperature of products 130, and the heat load of cooling device 100 all achieved their target values ​​during both inside defrosting operation and outside defrosting operation.

[0068] Moreover, Fig. 15 shows the results when about half the amount of products 130 as in the fully loaded state is placed in the cooling space 110. As shown in Fig. 15, it was found that the temperature of the cooling space 110, the temperature of the products 130, and the thermal load of the cooling device 100 all achieved the target values ​​during both the inside defrosting operation and the outside defrosting operation.

[0069] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0070] In the present embodiment, as described above, the cooling device 100 includes the cooling flow path 71 and the cooling flow path 72, and includes the multilayer flow path section 70 that multilayers the airflow inside the device, and is configured to switch between the cooling operation and the defrosting operation of each of the evaporators (41, 42) and the evaporators (43, 44). As a result, by performing the cooling operation of the evaporators (41, 42) while performing the defrosting operation of the evaporators (43, 44), it is possible to defrost the evaporators (43, 44) while continuing the cooling using the cooling flow path 71. In addition, by switching between the cooling operation and the defrosting operation, it is possible to defrost the evaporators (41, 42) while continuing the cooling using the cooling flow path 72 by performing the defrosting operation of the evaporators (41, 42) while performing the cooling operation of the evaporators (43, 44). As a result, it is possible to defrost the evaporators (evaporators (41, 42) and the evaporators (43, 44)) while suppressing an increase in the temperature of the cooling space 110.

[0071] In the present embodiment, as described above, the cooling device 100 is configured so that air curtains (E1, E2) that block the cooling space 110 from outside air are formed by blowing air out from each of the air outlets 61 and 62. As a result, the air curtains (E1, E2) are formed, and thus it is possible to suppress the inflow of outside air into the cooling space 110, and therefore it is possible to suppress an increase in the temperature of the cooling space 110. As a result, it is possible to prevent the formation (blowing) of the air curtains (E1, E2) from both the air outlets 61 and 62 from being stopped by switching between the cooling operation and the defrosting operation of each of the evaporators (41, 42) and (43, 44). As a result, it is possible to defrost the evaporators (the evaporators (41, 42) and (43, 44)) while suppressing an increase in the temperature of the cooling space 110 caused by stopping the formation of the air curtains (E1, E2).

[0072] In addition, in this embodiment, as described above, the cooling device 100 is configured such that the air outlet 61 blows out the air flowing through the cooling flow passage 71 to form the air curtain E1 that blocks the cooling space 110 from the outside air, and the air outlet 62 blows out the air flowing through the cooling flow passage 72 to form the air curtain E2 that blocks the cooling space 110 from the outside air. This makes it possible to prevent the formation (blowing) of both the air curtain E1 and the air curtain E2 from being stopped by switching between the cooling operation and the defrosting operation of each of the evaporators (41, 42) and (43, 44). As a result, it is possible to defrost the evaporators (the evaporators (41, 42) and (43, 44)) while suppressing an increase in the temperature of the cooling space 110 due to the stop of the formation of both the air curtain E1 and the air curtain E2.

[0073] In this embodiment, as described above, the cooling device 100 is configured so that the cooling flow path 71 includes the inner flow path 71a arranged along the cooling space 110 and connected to the air outlet 61, and the cooling flow path 72 includes the outer flow path 72a arranged along the inner flow path 71a on the opposite side of the cooling space 110 with respect to the inner flow path 71a and connected to the air outlet 62. As a result, when warm air flows through the outer flow path 72a, the inner flow path 71a is provided between the outer flow path 72a and the cooling space 110, so that it is possible to suppress the temperature of the cooling space 110 from increasing due to the heat of the warm air in the outer flow path 72a.

[0074] In this embodiment, as described above, the cooling device 100 is configured so that two-layered air curtains E1 and E2 are formed by blowing air out of each of the air outlets 61 and 62. This makes it possible to more reliably prevent outside air from entering the cooling space 110, compared to a case in which only one of the air curtains E1 and E2 is formed.

[0075] In this embodiment, as described above, the cooling device 100 is configured such that an opening 110d that communicates the inner flow path 71a and the cooling space 110 is provided on the side surface 110c of the cooling space 110 that is disposed between the bottom surface 110a of the cooling space 110 on which the product 130 is placed and the upper end portion 110b of the cooling space 110. This makes it possible to more reliably suppress an increase in the temperature of the cooling space 110 by allowing the cooling air to flow out of the inner flow path 71a into the cooling space 110 through the opening 110d when the cooling air (air curtain E1) is blown out from the air outlet 61. In addition, when air is sucked in from the air outlet 61 and the cooling air (air curtain E2) is blown out from the air outlet 62, a part of the air in the cooling space 110 is sucked into the inner flow path 71a through the opening 110d, so that the air in the cooling space 110 can be more efficiently sucked into the inner flow path 71a. As a result, the generation of air vortexes in the cooling space 110 can be suppressed, and the air curtain E2 can be suppressed from bending due to the generation of vortexes.

[0076] In addition, in this embodiment, as described above, the cooling device 100 is configured so that the width W4 of the air outlet 62 is larger than the width W5 of the air outlet 61 in the direction in which the air outlet 61 and the air outlet 62 are arranged. This makes it possible to reduce the speed of the air blown out from the air outlet 62 compared to when the width W4 of the air outlet 62 is equal to or smaller than the width W5 of the air outlet 61. As a result, it is possible to suppress the formation of a vortex caused by the high speed of the air blown out from the air outlet 62. As a result, it is possible to suppress the air forming the vortex from flowing in a manner that expands toward the air curtain E2, and it is also possible to suppress the air curtain E2 from being curved by the air flowing in a manner that expands toward the air curtain E2.

[0077] In the present embodiment, as described above, the cooling device 100 is configured to switch between an inside defrosting operation in which the air curtain E2 is formed by the air outlet 62 and the frost adhering to the evaporator (41, 42) is removed by air pressure sucked in from the air outlet 61, and an outside defrosting operation in which the air curtain E1 is formed by the air outlet 61 and the blower (53, 54) is rotated forward while the evaporator (43, 44) is defrosted at a temperature at which the frost melts. As a result, during the inside defrosting operation, the air pressure defrosting is performed in the evaporator (41, 42), so that the temperature of the air that has defrosted the evaporator (41, 42) can be made relatively low compared to the case where melting and defrosting is performed in the evaporator (41, 42). As a result, even if the air that has defrosted the evaporator (41, 42) flows into the cooling flow passage 72, the temperature of the air flowing through the cooling flow passage 72 (the temperature of the air curtain E2) can be prevented from increasing. Furthermore, during the outer defrosting operation, melting and defrosting is performed in the evaporator (43, 44), so that the evaporator (43, 44) can be defrosted relatively quickly compared to when wind pressure defrosting is performed in the evaporator (43, 44). During the outer defrosting operation, the air curtain E1 is formed by the air flowing through the inner flow path 71a, so that the air curtain E1 can prevent the air (air curtain E2) that has been warmed by melting and defrosting from flowing into the cooling space 110. Therefore, during the outer defrosting operation, the evaporator (43, 44) can be defrosted relatively quickly while preventing the temperature of the cooling space 110 from increasing.

[0078] In addition, in the present embodiment, as described above, the cooling device 100 is configured to include the windshield plate 91 provided on the inner flow path 71a side of the evaporator (41, 42) and extending in a direction intersecting the air flow so as to block a part of the cooling flow path 71, and the windshield plate 92 provided on the outer flow path 72a side of the evaporator (43, 44) and extending in a direction intersecting the air flow so as to block a part of the cooling flow path 72. This allows the airflow to meander when passing through each of the windshield plate 91 and the windshield plate 92. As a result, the direction of at least a part of the airflow can be changed more easily than when the air moves straight without the windshield plate 91 and the windshield plate 92. This allows the air to be easily diffused in the direction in which the evaporators (41, 42) and the evaporators (43, 44) are arranged, and therefore makes it possible to suppress non-uniformity in the wind speed distribution in the direction in which the evaporators (41, 42) and the evaporators (43, 44) are arranged. As a result, it is possible to suppress the occurrence of temperature unevenness depending on the position in the cooling space 110.

[0079] (Modification) The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the embodiments above, and further includes all modifications (variations) within the meaning and scope of the claims.

[0080] For example, in the above embodiment, the cooling device 100 is an apparatus for a showcase forming an air curtain (E1, E2), but the present invention is not limited to this. The cooling device may be an apparatus for cooling an apparatus (cooling cabinet) with a door, such as a freezer or a refrigerator.

[0081] In the above embodiment, the cooling device 100 includes two layers of cooling flow paths, the inner flow path 71a and the outer flow path 72a, but the present invention is not limited to this. The cooling device may include three or more layers of cooling flow paths. For example, an inner flow path, an outer flow path, and an intermediate flow path provided between the inner flow path and the outer flow path may be provided. In this case, the cooling device can form a three-layered air curtain.

[0082] In the above embodiment, an example is shown in which the blower (51, 52) (inner blower) that blows air to the evaporator (41, 42) (first evaporator) and the blower (53, 54) (outer blower) that blows air to the evaporator (43, 44) (second evaporator) are provided, but the present invention is not limited to this. For example, only one of the blowers (51, 52) and the blower (53, 54) may be provided, and the evaporator to which air is to be blown may be switchable.

[0083] In the above embodiment, the cooling device 100 is provided with the opening 110d and the width W4 of the air outlet 62 is adjusted to obtain a cooling effect, but the present invention is not limited to this. For example, the air outlet 61 and the air outlet 62 may be provided at a distance from each other. This allows the air curtain E2 to be spaced apart from the air outlet 61. As a result, during the inside defrosting operation, the air in the cooling space 110 is easily sucked into the air outlet 61 without being interfered with by the air curtain E2. This suppresses the formation of a vortex in the cooling space 110. In addition, the air outlet 62 may be formed so that the air blowing direction of the air outlet 62 faces downward (toward the cooling space 110). This reduces the wind speed (in the horizontal direction) of the air curtain E2, thereby suppressing the formation of a vortex in the cooling space 110.

[0084] In the above embodiment, the blowers (53, 54) (outside blowers) are rotated in the forward direction during the outside defrosting operation, but the present invention is not limited to this. The blowers (53, 54) may be stopped during the outside defrosting operation.

[0085] In the above embodiment, the air curtains (E1, E2) are formed in the horizontal direction, but the present invention is not limited to this. For example, the air curtains may be formed in the vertical direction.

[0086] In the above embodiment, two evaporators are provided for each of the inner flow passage 71a and the outer flow passage 72a, but the present invention is not limited to this. One evaporator or three or more evaporators may be provided for each of the inner flow passage 71a and the outer flow passage 72a.

[0087] In the above embodiment, an example is shown in which defrosting by wind pressure is performed in the evaporator (41, 42) (first evaporator) during the inside defrosting operation, but the present invention is not limited to this. Melting and defrosting may be performed in the evaporator (41, 42) during the inside defrosting operation. In the above embodiment, an example is shown in which melting and defrosting is performed in the evaporator (43, 44) (second evaporator) during the outside defrosting operation, but the present invention is not limited to this. Only defrosting by wind pressure may be performed in the evaporator (43, 44) during the outside defrosting operation. In this case, a separate mechanism for collecting the blown off frost is required in the cooling flow path 72.

[0088] In the above embodiment, one of the evaporators (41, 42) (first evaporator) and the evaporator (43, 44) (second evaporator) performs the cooling operation and the other performs the defrosting operation, but the present invention is not limited to this. There may be a timing when both the evaporator (41, 42) and the evaporator (43, 44) perform the cooling operation. [Explanation of symbols]

[0089] 10 Compressor 20 Condenser 31, 32, 33, 34 Expansion valve (expansion section) 41, 42 Evaporator (first evaporator) 43, 44 Evaporator (second evaporator) 52, 52 Blower (inside blower) 53, 54 Air blower (outside air blower) 61 Air outlet (1st air outlet) 62 Air outlet (second air outlet) 70 Multilayer channel section 71 Cooling channel (first cooling channel) 71a Inner passage 72 Cooling channel (second cooling channel) 72a Outside channel 91 Windshield plate (1st windshield plate) 92 Windshield plate (second windshield plate) 100 Cooling device 110 Cooling space 110a Bottom part 110b Upper end 110c side 110d opening 130 items E1 Air curtain (first air curtain) E2 Air curtain (second air curtain) W4 Width (width of second air outlet) W5 Width (width of first air outlet)

Claims

1. A cooling device including a compressor that compresses a refrigerant, a condenser that condenses the refrigerant discharged from the compressor, and an expansion section that expands the refrigerant condensed by the condenser, a first evaporator and a second evaporator for evaporating the refrigerant expanded by the expansion section; a blower for blowing air to the first evaporator and the second evaporator; a multilayer flow path section including a first cooling flow path for air sent from the blower to the first evaporator and blown out from a first outlet, and a second cooling flow path for air sent from the blower to the second evaporator and blown out from a second outlet, the multilayer flow path section multiplying the airflow inside the device, The first evaporator and the second evaporator are configured to be switched between a cooling operation and a defrosting operation, the first cooling passage includes an inner passage that is disposed along a cooling space, is connected to the first outlet, and has the first evaporator disposed therein; the second cooling flow passage includes an outer flow passage that is disposed along the inner flow passage on a side opposite to the cooling space with respect to the inner flow passage, is connected to the second outlet, and has the second evaporator disposed therein; In an operating state in which the second evaporator disposed in the outer flow passage is operated in a cooling operation while the first evaporator disposed in the inner flow passage is operated in a defrosting operation, frost adhered to the first evaporator disposed in the inner flow passage is removed by wind pressure using air sucked from the first air outlet, An air curtain is formed to isolate the cooling space from outside air by blowing air out of each of the first air outlet and the second air outlet, The first air outlet blows out air circulating through the first cooling flow path to form a first air curtain that blocks the cooling space from outside air, The second air outlet is configured to form a second air curtain that blocks the cooling space from outside air by blowing out air circulating through the second cooling flow path, The blower includes an inner blower for circulating air through the inner flow path and an outer blower for circulating air through the outer flow path, an inner defrosting operation in which the outer blower is rotated in a forward direction while the second evaporator is in a cooling operation, so that the air cooled by the second evaporator is blown out from the second outlet to form the second air curtain, and the inner blower is rotated in a reverse direction while the first evaporator is in a defrosting operation, so that the frost adhering to the first evaporator is removed by wind pressure using the air sucked in from the first outlet; The cooling device is configured to be able to switch between an outer defrosting operation in which the outer blower is rotated forward or stopped while the second evaporator is operated in a defrosting operation at a temperature at which frost melts, and an inner blower is rotated forward while the first evaporator is operated in a cooling operation, thereby blowing air cooled by the first evaporator out of the first outlet to form the first air curtain, and an outer defrosting operation in which the outer blower is rotated forward or stopped while the second evaporator is operated in a defrosting operation at a temperature at which frost melts.

2. The cooling device according to claim 1 , wherein the first air curtain and the second air curtain are formed in two layers by blowing air out of each of the first air outlet and the second air outlet.

3. 3. The cooling device according to claim 1, wherein an opening is provided on a side surface of the cooling space that is located between a bottom surface of the cooling space on which a product is placed and an upper end of the cooling space, the opening communicating the inner flow path with the cooling space.

4. 4. The cooling device according to claim 1, wherein a width of the second air outlet is larger than a width of the first air outlet in a direction in which the first air outlet and the second air outlet are aligned.

5. The first evaporator and the second evaporator are arranged side by side along a direction intersecting a direction in which air flows, a first wind shield provided on the inner flow passage side of the first evaporator and extending in a direction intersecting the air flow direction so as to block a part of the first cooling flow passage; The cooling device according to any one of claims 1 to 4, further comprising a second wind shield provided on the outer flow path side of the second evaporator and extending crosswise to the direction in which the air flows so as to block a portion of the second cooling flow path.

Images