Cooling device

Abstract

To provide a cooling device which suppresses increase in heat load during defrosting of an evaporator, and which can easily perform internal temperature maintenance.SOLUTION: A cooling device 100 includes: a compressor 10; a condenser 20; an evaporator 41 and an evaporator 42 for evaporating a refrigerant; a first air flow passage A1 in which the evaporator 41 is provided inside; and a second air flow passage A2 in which the evaporator 42 is provided inside, and which is provided separately from the first air flow passage A1. Then, the cooling device 100 is constituted so as to switch cooling operation and defrosting operation of the evaporator 41, and it is constituted so as to cool a cooling space where merchandise is stored, in the state where the temperature of the refrigerant flowing in the evaporator 42 provided in the second air flow passage A2 is made to be higher than the temperature at which frost formation occurs in the evaporator 42, in the cooling operation of the evaporator 41 provided in the first air flow passage A1.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cooling device, and more particularly to a cooling device configured to switch between a cooling operation and a defrosting operation of an evaporator. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a freezer / refrigerator showcase (cooling device) configured so that an evaporator can be switched between a cooling operation and a defrosting operation (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a cooling device that includes multiple evaporators and that switches between cooling operation and defrosting operation of the multiple evaporators. The cooling device described in the above-mentioned Patent Document 1 is configured to alternately switch between cooling operation and defrosting operation of the multiple evaporators, thereby cooling the interior of the storage unit by the evaporators and removing frost on the evaporators (defrosting) in parallel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-89901 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the cooling device as described in the above Patent Document 1, the cooling operation and the defrosting operation of the multiple evaporators are alternately switched to cool the inside of the cabinet by the evaporators and remove the frost on the evaporators (defrosting) in parallel, so that when the evaporators are defrosted, it is necessary to cool the air (cooling operation) to maintain the temperature inside the cabinet only with the evaporators that are not performing the defrosting operation among the multiple evaporators. Therefore, in the cooling device as described in the above Patent Document 1, if the amount of heat (heat load) required to maintain the cooling temperature inside the cabinet when the evaporators are defrosted is large, the evaporators that are not performing the defrosting operation alone cannot perform sufficient cooling, and the temperature inside the cabinet cannot be easily maintained. In other words, there is a problem that when the heat load when the evaporators are defrosted increases, the temperature inside the cabinet cannot be easily maintained.

[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 can easily maintain the temperature inside the cabinet by suppressing an increase in thermal load when defrosting the evaporator. [Means for solving the problem]

[0007] In order to achieve the above object, a cooling device according to one aspect of the present invention includes a compressor that compresses a refrigerant, a condenser that condenses the refrigerant discharged from the compressor, a main evaporator and a sub-evaporator that evaporate the refrigerant condensed by the condenser, a first air flow path in which the main evaporator is provided, and a second air flow path in which the sub-evaporator is provided and which is provided separately from the first air flow path, and is configured to switch between a cooling operation and a defrosting operation of the main evaporator, and is configured to cool a cooling space in which products are stored, while keeping the temperature of the refrigerant flowing through the sub-evaporator provided in the second air flow path higher than the temperature of the refrigerant flowing through the main evaporator and the temperature at which frost forms on the sub-evaporator during cooling operation of the main evaporator provided in the first air flow path. and further comprising a mixing region for mixing the air flowing out of the first air flow path and the air flowing out of the second air flow path. .

[0008] In the cooling device according to the above aspect, as described above, during the cooling operation of the main evaporator provided in the first air flow path, the cooling space in which the product is stored is cooled in a state in which the temperature of the refrigerant flowing through the sub-evaporator provided in the second air flow path is set higher than the temperature of the refrigerant flowing through the main evaporator and the temperature at which frost occurs on the sub-evaporator. As a result, during the cooling operation of the main evaporator, the sub-evaporator can assist the main evaporator in cooling the air while preventing frost on the sub-evaporator. As a result, there is no need to perform an operation for defrosting the sub-evaporator, and the amount of frost on the main evaporator can be reduced compared to when air is cooled only by the main evaporator, so that the main evaporator can be defrosted in a short time and with a low heat load. In addition, the main evaporator and the sub-evaporator are provided in the first air flow path and the second air flow path, which are provided separately from each other. As a result, the sub-evaporator can efficiently cool the air when the main evaporator is defrosted, compared to when the main evaporator and the sub-evaporator are provided in the same air flow path. As a result, the temperature rise in the cooling space (inside the cabinet) during defrosting of the main evaporator can be suppressed compared to when the main evaporator and the sub-evaporator are provided in the same air flow path. As a result, the increase in the thermal load during defrosting of the evaporator (main evaporator) can be suppressed, and the inside temperature can be easily maintained.

[0009] In the cooling device according to the above aspect, the main evaporator and the sub-evaporator are preferably arranged so as not to overlap when viewed from the direction in which the first air flow path and the second air flow path are adjacent. With this configuration, it is possible to suppress an increase in the size of the cooling device in the direction in which the first air flow path and the second air flow path are adjacent, compared to a case in which the main evaporator and the sub-evaporator overlap when viewed from the direction in which the first air flow path and the second air flow path are adjacent.

[0010] In the cooling device according to the above aspect, the first air flow path in which the main evaporator is provided is preferably arranged closer to the cooling space than the second air flow path in which the sub-evaporator is provided. By configuring in this way, the first air flow path in which the main evaporator is provided is arranged closer to the cooling space than the second air flow path in which the sub-evaporator is provided, so that the main evaporator, in which the temperature of the refrigerant flowing therethrough is lower than the temperature of the refrigerant flowing through the sub-evaporator during cooling operation, can be arranged on the cooling space side. As a result, the cooling temperature of the cooling space (inside the cabinet) can be efficiently maintained.

[0011] In the cooling device according to the above aspect, preferably, the cooling device further comprises a discharge portion that discharges air cooled by the main evaporator and the sub-evaporator, a rear air flow path that is provided on a rear side of the cooling space and between the cooling space and the first air flow path, The mixing region further comprises: The air flowing out from the first air flow path and the air flowing out from the second air flow path are mixed and distributed to the discharge side flow path and the rear air flow path. do. With this configuration, the mixing area can mix the air flowing out from the first air flow path and the second air flow path, and distribute the mixed air to the discharge side flow path and the rear air flow path. As a result, even if the temperature of the refrigerant flowing through the main evaporator and the sub-evaporator changes during cooling operation and defrosting operation of the main evaporator, the temperature variation of the air distributed to the discharge side flow path and the rear air flow path during each operation can be suppressed, and the temperature of the cooling space (inside the refrigerator) can be easily maintained.

[0012] In the cooling device according to the above aspect,Preferably, the air conditioner further includes a wall portion provided downstream of the mixing region so as to block a portion of the air flowing out from the first air flow path and the second air flow path to be mixed by the mixing region. With this configuration, the wall portion blocks a portion of the air flowing out from the first air flow path and the second air flow path downstream of the mixing region, thereby making it possible to circulate the air flowing out from each of the first air flow path and the second air flow path in a swirling manner in the mixing region. As a result, the air flowing out from each of the first air flow path and the second air flow path can be efficiently mixed in the mixing region.

[0013] The cooling device according to the above aspect In the above, the air conditioner preferably further includes an induction section for guiding air flowing out from at least one of the first air flow path and the second air flow path to the mixing region. With this configuration, the induction section guides the air flowing out from at least one of the first air flow path and the second air flow path to the mixing region, so that the air flowing out from each of the first air flow path and the second air flow path can be mixed more efficiently in the mixing region. As a result, the temperature variation of the air distributed to each of the discharge portion side flow path and the rear air flow path can be more efficiently suppressed.

[0014] The above mixed region The air flowing out of the first air flow path and the air flowing out of the second air flow path are mixed and distributed to the discharge side air flow path and the rear air flow path.In the configuration, preferably, a dividing member is further provided for dividing the air flow path between the mixing region and the discharge portion into an outer air flow path and an inner air flow path disposed closer to the cooling space than the outer air flow path, and the discharge portion is configured to discharge cooled air from above downward, and includes an inner discharge portion provided in communication with the inner air flow path for forming an inner air curtain that blocks the cooling space from outside air, and an outer discharge portion provided in communication with the outer air flow path for forming an outer air curtain outside the inner air curtain that blocks the cooling space from outside air, and the outer air flow path and the second air flow path are provided outside the inner air flow path and the first air flow path, respectively, with respect to the cooling space. With this configuration, even if the air is not mixed sufficiently in the mixing region during the cooling operation of the main evaporator, the air cooled by the auxiliary evaporator, whose flowing refrigerant has a higher temperature than the main evaporator, is likely to flow from the second air flow path into the outer air flow path. As a result, even if the air is not mixed sufficiently in the mixing region during the cooling operation of the main evaporator, the temperature of the inner air curtain can be made lower than the temperature of the outer air curtain. As a result, when the main evaporator is in cooling operation, the temperature of the air curtain on the cooling space side (inside the storage compartment) can be lowered, making it easy to maintain the temperature of the cooling space (inside the storage compartment).

[0015] The above mixed region The air flowing out of the first air flow path and the air flowing out of the second air flow path are mixed and distributed to the discharge side air flow path and the rear air flow path.In the configuration, the cooling device further includes a plate-shaped rear plate having rear blowing holes for discharging the air mixed in the mixing area from the rear air flow path toward the cooling space in the horizontal direction, preferably on the rear side of the cooling space and between the cooling space and the rear air flow path, along the vertical direction, and a horizontal discharge hole for discharging the air cooled by the main evaporator in the first air flow path from the first air flow path toward the rear air flow path in the horizontal direction. With this configuration, the air flowing in the rear air flow path can be pushed out from the rear blowing holes by discharging the air cooled by the main evaporator in the first air flow path from the first air flow path toward the rear air flow path in the horizontal direction. As a result, the air mixed in the mixing area after cooling by the main evaporator and the sub evaporator and flowing in the rear air flow path can be easily sent from the rear blowing holes to the cooling space, so that the cooling space (interior) can be cooled more effectively.

[0016] In the cooling device according to the above aspect, the temperature of the refrigerant flowing through the sub-evaporator during defrosting operation of the main evaporator is preferably lower than the temperature of the refrigerant flowing through the main evaporator during cooling operation of the main evaporator, and the sub-evaporator is configured to have a larger heat transfer area than the main evaporator. With this configuration, the sub-evaporator has a larger heat transfer area than the main evaporator provided in the first air flow path, so that the heat transfer efficiency of the sub-evaporator is improved compared to when the heat transfer areas of the main evaporator and the sub-evaporator are approximately the same. As a result, even when the sub-evaporator cools the air during defrosting operation of the main evaporator, the cooling space S (inside the storage unit) can be stably cooled (temperature maintained).

[0017] In the cooling device according to the above aspect, the first air flow path and the second air flow path are preferably formed to extend in a vertical direction so that the air to be cooled flows from below to above, and the first air flow path further includes an inclined portion above the main evaporator, the inclined portion inclining inwardly as it extends upward. With this configuration, moisture contained in the air flowing through the first air flow path hits the inclined portion and condenses, thereby reducing the moisture content of the air flowing downstream of the inclined portion. As a result, an increase in humidity of the air flowing out of the first air flow path can be suppressed.

[0018] The cooling device according to the above aspect preferably further comprises a temperature sensor provided in the first air flow path at least one of downstream of the main evaporator and an outer surface of the main evaporator to detect temperature. With this configuration, when the temperature sensor is provided downstream of the main evaporator, the temperature sensor can detect a change in temperature of the air cooled by the main evaporator, so that completion of defrosting of the main evaporator can be easily detected. Also, when the temperature sensor is provided on the outer surface of the main evaporator, the temperature sensor can detect a change in temperature of the outer surface of the main evaporator, so that completion of defrosting of the main evaporator can be easily detected. Effect of the Invention

[0019] According to the present invention, as described above, it is possible to provide a cooling device that can easily maintain the internal temperature by suppressing an increase in heat load when defrosting the evaporator. [Brief description of the drawings]

[0020] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a cooling device according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a cross-sectional view of a cooling device according to a first embodiment. [Diagram 3] FIG. 4 is a cross-sectional view showing a first air flow path and a second air flow path. [Figure 4] 4 is a partially enlarged view of the periphery of an inclined portion in FIG. 3. [Diagram 5] FIG. 4 is a partially enlarged view of the periphery of the mixed region in FIG. 3. [Figure 6] FIG. 11 is a partial cross-sectional view of the periphery of an inclined portion of a cooling device according to a second embodiment. [Figure 7] FIG. 11 is a partial cross-sectional view of the periphery of a discharge hole of a cooling device according to a third embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a cooling device according to a fourth embodiment. [Figure 9] FIG. 11 is a cross-sectional view of a cooling device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] [First embodiment] The overall configuration of a cooling device 100 according to a first embodiment of the present invention will be described with reference to FIGS.

[0023] As shown in FIG. 1, the cooling device 100 includes a compressor 10 and a condenser 20. 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. The condenser 20 is configured to condense the refrigerant discharged from the compressor 10. In addition, the condenser 20 is provided with a blower fan 21. The blower fan 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 fan 21.

[0024] The cooling device 100 also includes first expansion valves 31 and 32 and evaporators 41 and 42. The first expansion valves 31 and 32 are configured to expand the refrigerant condensed by the condenser 20. The compressor 10 and the condenser 20 are provided in common with the evaporators 41 and 42. The first expansion valves 31 and 32 are configured, for example, as needle valves. The openings of the first expansion valves 31 and 32 are adjusted by stepping motors (not shown) attached to the first expansion valves 31 and 32. The flow rates of the refrigerant to the evaporators 41 and 42 provided downstream of the first expansion valves 31 and 32 are adjusted by adjusting the openings of the first expansion valves 31 and 32.

[0025] The evaporators 41 and 42 are configured to evaporate the refrigerant condensed by the condenser 20. The evaporators 41 and 42 are configured to evaporate the refrigerant expanded by the first expansion valves 31 and 32, respectively. The evaporators 41 and 42 are arranged in parallel with each other. The evaporators 41 and 42 include a refrigerant flow path through which the refrigerant flows and a heat transfer surface that transfers the temperature of the refrigerant. Specifically, the evaporators 41 and 42 include a plurality of flat plates arranged in parallel with each other and made of a metal such as aluminum. The flat plates are made of a metal such as aluminum. The front and back surfaces of the flat plates are heat transfer surfaces. The refrigerant flow path penetrates the plurality of flat plates and is arranged to meander. The evaporators 41 and 42 are examples of the "main evaporator" and "auxiliary evaporator" in the claims, respectively.

[0026] The evaporator 42 is configured to have a larger heat transfer area than the evaporator 41. That is, the evaporator 42 is configured to have a larger area (surface area) of the heat transfer surface than the evaporator 41, as described above.

[0027] The cooling device 100 also includes a blower fan 43. The blower fan 43 is configured to send air to the evaporators 41 and 42. The blower fan 43 is also provided to circulate the taken-in outside air through a first air flow path A1 and a second air flow path A2, which will be described later. That is, the blower fan 43 is provided in common to the evaporators 41 and 42 (the first air flow path A1 and the second air flow path A2).

[0028] The cooling device 100 also includes a second expansion valve 51 that expands the refrigerant flowing out of the evaporator 42. The second expansion valve 51 is, for example, a needle valve, similar to the first expansion valves 31 and 32. The opening degree of the second expansion valve 51 is adjusted by a stepping motor (not shown) attached to the second expansion valve 51. The flow rate of the refrigerant to the evaporator 42 provided upstream is adjusted (controlled) by adjusting the opening degree of the second expansion valve 51. That is, the refrigerant pressure (refrigerant amount) in the evaporator 42 is controlled according to the opening degree of the second expansion valve 51. The second expansion valve 51 also throttles the refrigerant passing therethrough to impart a pressure loss (pressure difference). That is, the evaporation pressure (evaporation temperature) and the refrigerant temperature in the upstream evaporator 42 rise by the amount of the pressure loss caused by the second expansion valve 51, relative to the low pressure (suction pressure) determined by the rotation speed of the compressor 10.

[0029] The cooling device 100 also includes temperature sensors 61 and 62. The temperature sensor 61 is configured to detect the temperature in a first air flow path A1, which will be described later. The temperature sensor 62 is configured to detect the temperature downstream of a second air flow path A2, which will be described later. Signals (detection signals) based on the detection results of the temperature sensors 61 and 62 are also configured to be transmitted to the control unit 70.

[0030] The cooling device 100 also includes a control unit 70. The control unit 70 is configured to control the entire cooling device 100. Specifically, the control unit 70 is configured to control the opening degrees of the first expansion valve 31, the first expansion valve 32, and the second expansion valve 51. The control unit 70 is also configured to control the operations of the compressor 10, the blower fan 21, and the blower fan 43. The control unit 70 includes a CPU (Central Processing Unit) and a memory.

[0031] As shown in FIG. 2, the cooling device 100 is a vertical showcase including a plate-shaped back panel 80 extending along the vertical direction (Z direction) and a plurality of shelves 81 on which products are placed. The cooling device 100 is a refrigerated showcase in which a plurality of shelves 81 are arranged and which cools a cooling space S (interior) in which products are stored to a chilled temperature range. For example, the cooling device 100 is configured to cool the cooling space S in a range of −2° C. to 6° C. In this specification, the vertical direction is defined as the Z direction, the front-rear direction is defined as the X direction, and the left-right direction is defined as the Y direction. The upper direction is defined as the Z1 direction, and the lower direction is defined as the Z2 direction. The front side of the cooling device 100 is defined as the X1 direction, and the back side (rear side) of the cooling device 100 is defined as the X2 direction. When viewed from the front side (X1 direction) of the cooling device 100, the right side is defined as the Y1 direction, and the left side is defined as the Y2 direction.

[0032] 2, the cooling device 100 includes an inlet 91 and an outlet 92. The cooling device 100 is configured to cool the outside air (air) sucked in through the inlet 91 by the evaporators 41 and 42. The outlet 92 is configured to discharge the air cooled by the evaporators 41 and 42 from above downward (Z2 direction side). The outlet 92 is an example of a "discharge section" in the claims.

[0033] 2, the cooling device 100 includes a first air flow path A1 in which an evaporator 41 is provided, and a second air flow path A2 in which an evaporator 42 is provided. The second air flow path A2 is provided separately from the first air flow path A1.

[0034] 2, the cooling device 100 includes a rear air flow path A3. The rear air flow path A3 is provided on the rear side (X2 direction side) of the cooling space S and between the cooling space S and the first air flow path A1.

[0035] The rear plate 80 is provided on the rear side (X2 direction side) of the cooling space S, between the cooling space S and the rear air flow path A3, so as to extend in the up-down direction (Z direction).

[0036] 2, the blower fan 43 is provided in the flow path between the air inlet 91 and the first air flow path A1 (the second air flow path A2). As described above, the blower fan 43 is provided commonly to the evaporators 41 and 42 (the first air flow path A1 and the second air flow path A2). Note that the blower fan 43 may be provided corresponding to each of the evaporators 41 and 42 (the first air flow path A1 and the second air flow path A2). Furthermore, a plurality of blower fans 43 may be provided adjacent to each other in the left-right direction (Y direction).

[0037] 2, the cooling device 100 includes dividing members 93, 94, and 95. The dividing members 93, 94, and 95 are provided in a flow path between the suction port 91 (blower fan 43) and the discharge port 92.

[0038] The dividing member 93 is provided between the evaporator 41 and the evaporator 42. The dividing member 93 is configured to divide a space in a flow path between the suction port 91 and the discharge port 92, and to branch the outside air taken in by the suction port 91 into a first air flow path A1 and a second air flow path A2.

[0039] Moreover, the dividing member 94 is provided between the evaporator 41 and the rear plate 80. The dividing member 94 divides the space between the rear plate 80 and the dividing member 93 (evaporator 41), and is configured to form a first air flow path A1 together with the dividing member 93. The dividing member 94 is configured to form a rear air flow path A3 together with the rear plate 80.

[0040] The first air flow path A1 in which the evaporator 41 is provided is disposed closer to the cooling space S side (X1 direction side) than the second air flow path A2 in which the evaporator 42 is provided.

[0041] The first air flow path A1 and the second air flow path A2 are formed to extend in the up-down direction (Z direction) so that the cooling air flows from below to above.

[0042] The dividing member 95 is configured to form an inner air flow path A4 and an outer air flow path A5. As shown in Fig. 2, the dividing member 95 is configured to divide the air flow path between a mixing region M (described later) and a discharge port 92 into an outer air flow path A5 and an inner air flow path A4 that is disposed closer to the cooling space S than the outer air flow path A5. The outer air flow path A5 and the second air flow path A2 are provided on the outer side of the inner air flow path A4 and the first air flow path A1, respectively, with respect to the cooling space S (on the opposite side to the side where the cooling space S is disposed with respect to the inner air flow path A4 and the first air flow path A1, respectively).

[0043] 2, the evaporator 41 and the evaporator 42 are arranged so as not to overlap when viewed from the direction in which the first air flow path A1 and the second air flow path A2 are adjacent to each other (the X1 direction side or the X2 direction side). The evaporator 41 is arranged below the evaporator 42 (the Z2 direction side). The evaporator 41 and the evaporator 42 are arranged so as to partially overlap when viewed from above (the Z1 direction side) or below (the Z2 direction side).

[0044] As shown in FIG. 2, the discharge port 92 includes an inner discharge port 92a and an outer discharge port 92b. The inner discharge port 92a is provided in communication with the inner air flow path A4. The air discharged from the inner discharge port 92a forms an inner air curtain C1 that blocks the cooling space S from the outside air. The outer discharge port 92b is provided in communication with the outer air flow path A5. The air discharged from the outer discharge port 92b forms an outer air curtain C2 that blocks the cooling space S from the outside air. The outer air curtain C2 is formed outside (X1 direction side) the inner air curtain C1. Specifically, the outer air curtain C2 is formed on the opposite side (X1 direction side) to the side where the cooling space S is arranged with respect to the inner air curtain C1. The inner discharge port 92a is an example of an "inner discharge portion" in the claims, and the outer discharge port 92b is an example of an "outer discharge portion" in the claims. Furthermore, the inner air curtain C1 is an example of an "inner air curtain" in the claims, and the outer air curtain C2 is an example of an "outer air curtain" in the claims.

[0045] The rear plate 80 also has rear air blowing holes 80a (see FIGS. 2 and 3) for discharging the air mixed by a mixing region M, which will be described later, from the rear air flow path A3 toward the cooling space S in the horizontal direction (X direction). A plurality of rear air blowing holes 80a are provided in the rear plate 80.

[0046] The cooling device 100 maintains (cools) the temperature of the cooling space S (inside the storage unit) in which the products are stored by discharging air cooled by the evaporators 41 and 42 from the outlet 92 (the inner outlet 92a and the outer outlet 92b) and the rear blowing holes 80a provided in the rear panel 80.

[0047] (slanted part) 4, the first air flow path A1 is configured such that a flow path width W2 on the downstream side (Z1 direction side) is smaller (narrower) than a flow path width W1 at a portion where the evaporator 41 is disposed. The cooling device 100 includes inclined portions 93a and 94a that are inclined inwardly upward above the evaporator 41 in the first air flow path A1 (Z1 direction side). Specifically, the dividing members 93 and 94 have inclined portions 93a and 94a, respectively, that are inclined inwardly upward on the downstream side (Z1 direction side) of the evaporator 41 so that the distance between them becomes narrower.

[0048] Further, the first air flow path A1 is configured so that a flow path width W1 at a portion where the evaporator 41 is disposed is larger (wider) than a flow path width W3 upstream (Z2 direction side) of a portion where the evaporator 42 is disposed in the second air flow path A2. Further, in the first embodiment, the flow path width W3 is configured so that it is larger (wider) than the flow path width W2.

[0049] In the first embodiment, as described above, the blower fan 43 is provided in common for the first air flow path A1 and the second air flow path A2. Therefore, in the cooling device 100, the flow rate of air flowing through the first air flow path A1 and the second air flow path A2 is adjusted (air volume ratio is adjusted) by the flow path width (duct width) of each of the first air flow path A1 and the second air flow path A2. For example, when too much air flows through one of the first air flow path A1 and the second air flow path A2, the flow path width of one is made smaller (narrower) than the flow path width of the other to cause a pressure loss and adjust the air volume ratio.

[0050] 4, the temperature sensor 61 is provided on the outer surface of the evaporator 41 in the first air flow path A1. Specifically, the temperature sensor 61 is provided on the outer surface (outer surface 41a) of the evaporator 41 on the downstream side (Z1 direction side) of the first air flow path A1. The temperature sensor 61 detects the temperature of the outer surface (outer surface 41a) of the evaporator 41.

[0051] (mixed area) 5, the cooling device 100 is provided with a mixing region M. The mixing region M is a region where the air flowing out from the first air flow path A1 and the air flowing out from the second air flow path A2 are mixed. In the mixing region M, the mixed air is distributed to the flow paths on the discharge port 92 side (the inner air flow path A4 and the outer air flow path A5) and the rear air flow path A3.

[0052] 5, the dividing member 94 includes an induction portion 94b. The induction portion 94b is formed near the upper end of the dividing member 94 so as to extend toward the X2 direction side (the second air flow path A2 side) opposite to the side where the cooling space S is arranged. The induction portion 94b is configured to induce the air that flows out from at least one of the first air flow path A1 and the second air flow path A2 to the mixing region M.

[0053] In the first embodiment, the guiding section 94b is configured to guide the air flowing out of the first air flow path A1 toward the X2 direction side (the second air flow path A2 side), thereby guiding the air flowing out of the second air flow path A2 to the mixing region M. The guiding section 94b is formed so as to cover the evaporator 42 and a part of the second air flow path A2 when viewed from the downstream side (the Z1 direction side) of the evaporator 42. As a result, the guiding section 94b guides the air flowing out from the dividing member 93 side (the X1 direction side) of the second air flow path A2 toward the X2 direction side.

[0054] The dividing member 95 also includes a wall portion 95a. The wall portion 95a is formed so as to extend toward the cooling space S side (X1 direction side) near the lower end portion of the dividing member 95. The wall portion 95a is provided on the downstream side (Z1 direction side) of the mixing region M and is provided so as to block a part of the air flowing out from the first air flow path A1 and the second air flow path A2 to be mixed by the mixing region M. This allows the air flowing out from the first air flow path A1 and the second air flow path A2 to circulate in a swirling manner and be efficiently mixed.

[0055] The temperature sensor 62 is provided on the outer surface of the evaporator 42. Specifically, the temperature sensor 62 is provided on the outer surface (outer surface 42a) of the evaporator 42 that is on the downstream side (Z1 direction side) of the second air flow path A2. The temperature sensor 62 detects the temperature of the outer surface of the evaporator 42.

[0056] (Cooling operation) The cooling device 100 is configured to switch between cooling operations under the control of the control unit 70. Specifically, the cooling device 100 is configured to perform a first cooling operation in which cooling is performed by the evaporators 41 and 42, and a second cooling operation in which cooling is performed by the evaporator 42 while defrosting the evaporator 41. That is, the cooling device 100 is configured to switch between the cooling operation and the defrosting operation of the evaporator 41.

[0057] The first cooling operation is an operation having a longer operation time than the second cooling operation. For example, the operation time of the first cooling operation is about 1 hour to 2 hours, and the operation time of the second cooling operation is about 10 minutes to 15 minutes. That is, the first cooling operation is the main operation in the cooling operation of the cooling device 100. In addition, in the first cooling operation, the evaporator 42 is defrosted in addition to cooling the air, and in the second cooling operation, the evaporator 41 is defrosted in addition to cooling the air.

[0058] The cooling device 100 is configured to cool the cooling space S in which the goods are stored, during the first cooling operation (during cooling operation of the evaporator 41 provided in the first air flow path A1), while keeping the temperature of the refrigerant flowing through the evaporator 42 provided in the second air flow path A2 higher than the temperature of the refrigerant flowing through the evaporator 41 and the temperature at which frost forms on the evaporator 42.

[0059] Specifically, during cooling operation (first cooling operation) of the evaporator 41 provided in the first air flow path A1, the control unit 70 makes the pressure of the refrigerant flowing through the evaporator 42 higher than the pressure of the refrigerant flowing through the evaporator 41 by the second expansion valve 51, and makes the temperature of the refrigerant flowing through the evaporator 42 provided in the second air flow path A2 higher than the temperature of the refrigerant flowing through the evaporator 41 and the temperature at which frost forms on the evaporator 42.

[0060] (First cooling operation) An example of the first cooling operation in the first embodiment will be described. In the first cooling operation, the control unit 70 controls the evaporation temperature (refrigerant temperature) of the evaporator 41 to about -7°C by the first expansion valve 31. In addition, the control unit 70 controls the evaporation temperature (refrigerant temperature) of the evaporator 42 to about 1°C by balancing the opening degrees of the first expansion valve 32 and the second expansion valve 51.

[0061] Then, by the blowing of the blower fan 43, the air (outside air at about 10°C) flowing in from the suction port 91 branches into the first air flow path A1 and the second air flow path A2. In the first air flow path A1, the air flowing in from the suction port 91 is cooled to about -2°C by the evaporator 41. In the second air flow path A2, the air flowing in from the suction port 91 is dehumidified and cooled to about 2°C by the evaporator 42. At this time, the evaporator 42 cools the air flowing in from the suction port 91 without frosting.

[0062] The air cooled to about -2°C in the first air flow path A1 (by the evaporator 41) and the air dehumidified and cooled to about 2°C in the second air flow path A2 (by the evaporator 42) are mixed in the mixing region M (see FIG. 5). In the mixing region M, the air flowing out of the first air flow path A1 and the air flowing out of the second air flow path A2 are efficiently mixed by the wall portion 95a and the guide portion 94b.

[0063] The air mixed in the mixing area M and cooled to approximately 0°C flows into the outer air flow path A5 and the inner air flow path A4 and is discharged from the discharge port 92 as the outer air curtain C2 and the inner air curtain C1, respectively, and also flows into the rear air flow path A3 and is discharged into the cooling space S (inside the cabinet) as rear air through the rear air blowing hole 80a.

[0064] In addition, in the first embodiment, the temperature of the refrigerant flowing through the evaporator 42 during the second cooling operation (during defrosting operation of the evaporator 41) is configured to be lower than the temperature of the refrigerant flowing through the evaporator 41 during the first cooling operation (during cooling operation of the evaporator 41).

[0065] (Second cooling operation) An example of the second cooling operation in the first embodiment will be described. In the first embodiment, the temperature of the refrigerant flowing through the evaporator 42 during the second cooling operation (during the defrosting operation of the evaporator 41) is configured to be lower than the temperature of the refrigerant flowing through the evaporator 42 during the first cooling operation (during the cooling operation of the evaporator 41).

[0066] In the second cooling operation, the control unit 70 closes the first expansion valve 31 and stops the supply of refrigerant to the evaporator 41. The temperature of the refrigerant in the evaporator 41 becomes about 5°C. The control unit 70 also increases the opening of the second expansion valve 51 more than in the first cooling operation, reducing the flow resistance of the refrigerant and lowering the refrigerant temperature. In the second cooling operation, the refrigerant temperature in the evaporator 42 is lowered below the refrigerant temperature in the first cooling operation. For example, the refrigerant temperature is lowered from about 1°C in the first cooling operation to about -10°C.

[0067] Then, air (outside air at about 10° C.) flowing in from the suction port 91 is branched into the first air flow path A1 and the second air flow path A2 by the blowing of the blower fan 43. In the first air flow path A1, the air flowing in from the suction port 91 is cooled to about 6° C. by the evaporator 41. In the second air flow path A2, the air flowing in from the suction port 91 is cooled to about −6° C. by the evaporator 42. Note that frost adheres to the evaporator 42 due to a drop in the refrigerant temperature during the second cooling operation, but the frost that adheres to the evaporator 42 during the second cooling operation is melted and removed during the first cooling operation.

[0068] Then, similarly to the first cooling operation, the air (at about 6°C) flowing out of the first air flow path A1 and the air (at about -6°C) flowing out of the second air flow path A2 are mixed in the mixing area M (see FIG. 5). The air mixed in the mixing area M and cooled to about 0°C flows into the outer air flow path A5 and the inner air flow path A4, and is discharged from the discharge port 92 as the outer air curtain C2 and the inner air curtain C1, respectively, and also flows into the rear air flow path A3 and is discharged into the cooling space S (inside the refrigerator) as rear air through the rear air blowing holes 80a. This makes it possible to cool the cooling space S (maintain the temperature of the cooling space S) similarly to the first cooling operation while defrosting the evaporator 41.

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

[0070] In the first embodiment, during the cooling operation of the evaporator 41 provided in the first air flow path A1 (first cooling operation), the cooling space S in which the product is stored is cooled in a state in which the temperature of the refrigerant flowing through the evaporator 42 provided in the second air flow path A2 is set higher than the temperature of the refrigerant flowing through the evaporator 41 and the temperature at which frost occurs on the evaporator 42. As a result, during the cooling operation of the evaporator 41 (first cooling operation), the evaporator 42 can assist the evaporator 41 in cooling the air while preventing frost on the evaporator 42. As a result, there is no need to perform an operation for defrosting the evaporator 42, and the amount of frost on the evaporator 41 can be reduced compared to when air is cooled only by the evaporator 41, so that the evaporator 41 can be defrosted in a short time with a low heat load. In addition, the evaporators 41 and 42 are provided in the first air flow path A1 and the second air flow path A2, which are provided separately from each other. This allows the evaporator 42 to cool the air more efficiently when defrosting the evaporator 41, compared to when the evaporator 41 and the evaporator 42 are provided in the same air flow path. As a result, the increase in temperature in the cooling space S (inside the cabinet) when defrosting the evaporator 41 can be suppressed, compared to when the evaporator 41 and the evaporator 42 are provided in the same air flow path. As a result, the increase in the heat load when defrosting the evaporator 41 can be suppressed, and the inside temperature can be easily maintained.

[0071] In the first embodiment, as described above, the evaporators 41 and 42 are arranged so as not to overlap when viewed from the direction in which the first air flow path A1 and the second air flow path A2 are adjacent to each other (the X1 direction side or the X2 direction side). This makes it possible to suppress an increase in the size of the cooling device 100 in the direction in which the first air flow path A1 and the second air flow path A2 are adjacent to each other (the X direction) compared to a case in which the evaporators 41 and 42 overlap when viewed from the direction in which the first air flow path A1 and the second air flow path A2 are adjacent to each other.

[0072] In the first embodiment, as described above, the first air flow path A1 in which the evaporator 41 is provided is disposed closer to the cooling space S (X1 direction side) than the second air flow path A2 in which the evaporator 42 is provided. As a result, the first air flow path A1 in which the evaporator 41 is provided is disposed closer to the cooling space S (X1 direction side) than the second air flow path A2 in which the evaporator 42 is provided, so that the evaporator 41, in which the temperature of the refrigerant flowing therethrough is lower than the temperature of the refrigerant flowing through the evaporator 42, can be disposed on the cooling space S side during the cooling operation of the evaporator 41 (first cooling operation). As a result, the cooling temperature of the cooling space S (inside the storage unit) can be efficiently maintained.

[0073] In the first embodiment, as described above, the cooling space S is provided with an outlet 92 that discharges air cooled by the evaporators 41 and 42, and a rear air flow path A3 that is provided on the rear side (X2 direction side) of the cooling space S and between the cooling space S and the first air flow path A1. The mixing region M is provided to mix the air flowing out from the first air flow path A1 and the air flowing out from the second air flow path A2, and distribute the mixed air to the flow paths on the outlet 92 side (the inner air flow path A4 and the outer air flow path A5) and the rear air flow path A3. This allows the mixing region M to mix the air flowing out from each of the first air flow path A1 and the second air flow path A2, and distribute the mixed air to each of the flow paths on the outlet 92 side (the inner air flow path A4 and the outer air flow path A5) and the flow path on the rear air flow path A3 side. As a result, even if the temperature of the refrigerant flowing through each of the evaporators 41 and 42 changes during cooling operation and defrosting operation of the evaporator 41 (first cooling operation and second cooling operation), the variation in the temperature of the air distributed to each of the flow paths on the discharge port 92 side (inner air flow path A4 and outer air flow path A5) and the rear air flow path A3 during each operation can be suppressed, making it easy to maintain the temperature of the cooling space S (inside the storage unit).

[0074] In the first embodiment, as described above, the wall portion 95a is provided on the downstream side (Z1 direction side) of the mixing region M so as to block a part of the air flowing out from the first air flow path A1 and the second air flow path A2 to be mixed by the mixing region M. As a result, the wall portion 95a blocks a part of the air flowing out from the first air flow path A1 and the second air flow path A2 on the downstream side (Z1 direction side) of the mixing region M, so that the air flowing out from each of the first air flow path A1 and the second air flow path A2 can be circulated in a swirling manner in the mixing region M. As a result, the air flowing out from each of the first air flow path A1 and the second air flow path A2 can be efficiently mixed in the mixing region M.

[0075] In the first embodiment, as described above, the guide section 94b is configured to guide the air flowing out from each of the first air flow path A1 and the second air flow path A2 to the mixing region M. As a result, the guide section 94b guides the air flowing out from each of the first air flow path A1 and the second air flow path A2 to the mixing region M, so that the air flowing out from each of the first air flow path A1 and the second air flow path A2 can be mixed more efficiently in the mixing region M. As a result, the variation in temperature of the air distributed to each of the flow paths on the discharge section side (the inner air flow path A4 and the outer air flow path A5) and the back surface air flow path A3 can be more efficiently suppressed.

[0076] In the first embodiment, as described above, the outer air flow path A5 and the second air flow path A2 are provided outside the inner air flow path A4 and the first air flow path A1, respectively, with respect to the cooling space S. As a result, even if the air is not mixed sufficiently in the mixing region M during the cooling operation of the evaporator 41 (first cooling operation), the air cooled by the evaporator 42, in which the temperature of the refrigerant flowing therethrough is higher than that of the evaporator 41, is likely to flow from the second air flow path A2 into the outer air flow path A5. As a result, even if the air is not mixed sufficiently in the mixing region M during the cooling operation of the evaporator 41 (first cooling operation), the temperature of the inner air curtain C1 can be made lower than the temperature of the outer air curtain C2. As a result, the temperature of the air curtain on the cooling space S side (inside the storage unit) can be made lower during the cooling operation of the evaporator 41 (first cooling operation), so that the temperature of the cooling space S (inside the storage unit) can be easily maintained.

[0077] In the first embodiment, as described above, the temperature of the refrigerant flowing through the evaporator 42 during the defrosting operation (second cooling operation) of the evaporator 41 is configured to be lower than the temperature of the refrigerant flowing through the evaporator 41 during the cooling operation (first cooling operation) of the evaporator 41. The evaporator 42 is configured to have a larger heat transfer area than the evaporator 41. As a result, the evaporator 42 has a larger heat transfer area than the evaporator 41 provided in the first air flow path A1, and therefore the heat transfer efficiency of the evaporator 42 is improved compared to when the heat transfer areas of the evaporator 41 and the evaporator 42 are approximately the same. As a result, even when the evaporator 42 cools the air during the defrosting operation (second cooling operation) of the evaporator 41, the cooling space S (inside the storage unit) can be stably cooled (temperature maintained).

[0078] In the first embodiment, as described above, the first air flow path A1 and the second air flow path A2 are formed to extend in the vertical direction (Z direction) so that the air to be cooled flows from the bottom to the top. The inclined portions 93a and 94a are configured to incline inwardly as they move upward above the evaporator 41 of the first air flow path A1. This allows moisture contained in the air flowing through the first air flow path A1 to hit the inclined portions 93a and 94a and condense, thereby reducing the amount of moisture in the air flowing downstream of the inclined portions 93a and 94a. As a result, it is possible to suppress an increase in humidity of the air flowing out of the first air flow path A1.

[0079] In the first embodiment, as described above, the temperature sensor 61 is provided on the outer surface (outer surface 41a) of the evaporator 41 in the first air flow path A1 and is configured to detect the temperature. This allows the temperature sensor 61 to detect a change in temperature of the outer surface (outer surface 41a) of the evaporator 41, making it possible to easily detect the completion of defrosting of the evaporator 41.

[0080] [Second embodiment] The configuration of a cooling device 200 according to the second embodiment will be described with reference to Fig. 6. In the figure, the same reference numerals are used to designate the same components as those in the first embodiment.

[0081] In the cooling device 200 of the second embodiment, unlike the cooling device 100 of the first embodiment in which the temperature sensor 261 is provided on the outer surface (outer surface 41a) of the evaporator 41 in the first air flow path A1, the temperature sensor 261 is provided downstream of the evaporator 41 so as to be spaced apart from the evaporator 41. The temperature sensor 261 is configured to detect the temperature of the air cooled by the evaporator 41 downstream of the evaporator 41.

[0082] Other configurations of the second embodiment are similar to those of the first embodiment.

[0083] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0084] In the second embodiment, similarly to the first embodiment, an increase in the thermal load during defrosting of the evaporator 41 can be suppressed, and the temperature inside the refrigerator can be easily maintained.

[0085] In the second embodiment, as described above, the temperature sensor 261 is provided in the first air flow path A1 downstream of the evaporator 41 and configured to detect the temperature. This allows the temperature sensor 261 to detect a change in temperature of the air cooled by the evaporator 41, making it possible to easily detect the completion of defrosting of the evaporator 41.

[0086] Other effects of the second embodiment are similar to those of the first embodiment.

[0087] [Third embodiment] The configuration of a cooling device 300 according to the third embodiment will be described with reference to Fig. 7. In the figure, the same reference numerals are used to designate the same components as those in the first embodiment.

[0088] The cooling device 300 includes a plate-shaped rear plate 80 having rear air blowing holes 80a for discharging the air mixed in the mixing region M from the rear air passage A3 toward the cooling space S along the horizontal direction, as in the first embodiment. The cooling device 300 also includes discharge holes 394c for discharging the air cooled by the evaporator 41 in the first air passage A1 from the first air passage A1 toward the rear air passage A3 (X1 direction side) along the horizontal direction. The discharge holes 394c are holes provided in the dividing member 94 so as to communicate from the first air passage A1 to the rear air passage A3. The discharge holes 394c are an example of the "horizontal discharge holes" in the claims. A plurality of discharge holes 394c are provided in the dividing member 94.

[0089] In the third embodiment, the air is cooled by the evaporator 41 in the first air flow path A1 and discharged from the discharge hole 394c, so as to push out the air flowing through the rear air flow path A3, thereby assisting in the blowing of air from the rear air hole 80a.

[0090] The other configurations of the third embodiment are similar to those of the first embodiment.

[0091] (Effects of the third embodiment) In the third embodiment, the following effects can be obtained.

[0092] In the third embodiment, similarly to the first embodiment, an increase in the thermal load during defrosting of the evaporator 41 can be suppressed, and the temperature inside the refrigerator can be easily maintained.

[0093] In the third embodiment, as described above, a plate-shaped rear plate 80 having rear blowing holes 80a for discharging the air mixed by the mixing region M from the rear air flow path A3 toward the cooling space S along the horizontal direction is provided. The discharge holes 394c for discharging the air cooled by the evaporator 41 in the first air flow path A1 from the first air flow path A1 toward the rear air flow path A3 along the horizontal direction are provided. This allows the air flowing through the rear air flow path A3 to be pushed out from the rear blowing holes 80a by discharging the air cooled by the evaporator 41 in the first air flow path A1 from the first air flow path A1 toward the rear air flow path A3 along the horizontal direction. As a result, the air mixed in the mixing region M after cooling by the evaporator 41 and the evaporator 42 and flowing through the rear air flow path A3 can be easily sent from the rear blowing holes 80a to the cooling space S, so that the cooling space S (inside the refrigerator) can be cooled more effectively.

[0094] Other effects of the third embodiment are similar to those of the first embodiment.

[0095] [Fourth embodiment] The configuration of a cooling device 400 according to the fourth embodiment will be described with reference to Fig. 8. In the figure, the same reference numerals are used to designate the same components as those in the first embodiment.

[0096] The cooling device 400 in the fourth embodiment is configured to discharge the air cooled by the evaporators 41 and 42 without mixing them, unlike the cooling device 100 in the first embodiment that includes the mixing region M. In the cooling device 400, the air flow path between the intake port 91 (blower fan 43) and the exhaust port 92 is divided by a dividing member 493 into a first air flow path B1 in which the evaporator 41 is provided and a second air flow path B2 in which the evaporator 42 is provided. In the cooling device 400, the evaporator 41 is disposed below (on the Z2 direction side) the evaporator 42. In addition, the cooling device 400 includes an inclined portion 493a inclined inwardly as it goes upward, above (on the Z1 direction side) the evaporator 41 in the first air flow path B1. Specifically, the dividing member 493 has an inclined portion 493a inclined toward the cooling space S (X1 direction side) above the evaporator 41 of the first air flow path B1 (Z1 direction side). The inclined portion 493a is provided above the evaporator 41 (Z1 direction side) and below the evaporator 42 (Z2 direction side).

[0097] The second air flow path B2 is disposed on the opposite side of the first air flow path B1 from the side where the cooling space S is disposed. That is, the first air flow path B1 in which the evaporator 41 is provided is disposed closer to the cooling space S side (X1 direction side) than the second air flow path B2 in which the evaporator 42 is provided. The air cooled in the first air flow path B1 in which the evaporator 41 is provided is discharged as an inner air curtain C1 from the inner discharge port 92a, and is also discharged as a back air into the cooling space S (inside the cabinet) through the back air blowing holes 80a (see FIG. 3). The air cooled in the second air flow path B2 in which the evaporator 42 is provided is discharged as an outer air curtain C2 from the outer discharge port 92b.

[0098] (Cooling operation) The cooling device 400 is configured to switch between cooling operations under the control of the control unit 70. Specifically, like the cooling device 100 according to the first embodiment, the cooling device 400 is configured to perform a first cooling operation in which cooling is performed by the evaporators 41 and 42, and a second cooling operation in which cooling is performed by the evaporator 42 while defrosting the evaporator 41. That is, the cooling device 400 is configured to switch between the cooling operation and the defrosting operation of the evaporator 41.

[0099] (First cooling operation) An example of the first cooling operation in the fourth embodiment (cooling device 400) will be described. In the first cooling operation, the control unit 70 controls the evaporation temperature (refrigerant temperature) of the evaporator 41 to -7°C by the first expansion valve 31. In addition, the control unit 70 controls the evaporation temperature (refrigerant temperature) of the evaporator 42 to 1°C by the opening balance between the first expansion valve 32 and the second expansion valve 51.

[0100] Then, the air (outside air at about 12°C) flowing in from the suction port 91 is branched into the first air flow path B1 and the second air flow path B2 by the blowing of the blower fan 43. In the first air flow path B1, the air flowing in from the suction port 91 is cooled to about -2°C by the evaporator 41. The air cooled to about -2°C by the evaporator 41 is discharged from the inner discharge port 92a as an inner air curtain C1, and is also discharged as a rear air blown into the cooling space S (inside the cabinet) through the rear air blowing holes 80a.

[0101] In the second air flow path B2, the air flowing in from the suction port 91 is dehumidified and cooled to about 2° C. by the evaporator 42. At this time, the evaporator 42 cools the air flowing in from the suction port 91 without frosting. The air dehumidified and cooled to about 2° C. by the evaporator 42 is discharged from the outer discharge port 92b as the outer air curtain C2.

[0102] (Second cooling operation) An example of the second cooling operation in the fourth embodiment (cooling device 400) will be described. In the fourth embodiment, the temperature of the refrigerant flowing through the evaporator 42 during the second cooling operation (during the defrosting operation of the evaporator 41) is configured to be lower than the temperature of the refrigerant flowing through the evaporator 42 during the first cooling operation (during the cooling operation of the evaporator 41).

[0103] In the second cooling operation, the control unit 70 closes the first expansion valve 31 and stops the supply of refrigerant to the evaporator 41. The temperature of the refrigerant in the evaporator 41 becomes about 5°C. The control unit 70 also increases the opening of the second expansion valve 51 more than in the first cooling operation, reducing the flow resistance of the refrigerant and lowering the refrigerant temperature. In the second cooling operation, the refrigerant temperature in the evaporator 42 is lowered below the refrigerant temperature in the first cooling operation. For example, the refrigerant temperature is lowered from about 1°C in the first cooling operation to about -7°C.

[0104] Then, the air (outside air at about 10°C) flowing in from the suction port 91 is branched into the first air flow path B1 and the second air flow path B2 by the blowing of the blower fan 43. In the first air flow path B1, the air flowing in from the suction port 91 is cooled to about 6°C while defrosting the evaporator 41. The air cooled to about 6°C by the evaporator 41 is discharged as an inner air curtain C1 from the inner discharge port 92a, and is also discharged as a rear air blown into the cooling space S (inside the cabinet) through the rear air blowing holes 80a.

[0105] In the second air flow path B2, the air flowing in from the suction port 91 is cooled to about -2°C by the evaporator 42. The air cooled to about -2°C by the evaporator 42 is discharged as the outer air curtain C2 from the outer discharge port 92b. Note that, during the second cooling operation, frost that has adhered to the evaporator 42 is melted and removed (removed) during the first cooling operation.

[0106] The other configurations of the fourth embodiment are similar to those of the first embodiment.

[0107] (Effects of the fourth embodiment) In the fourth embodiment, the following effects can be obtained.

[0108] In the fourth embodiment, similarly to the first embodiment, an increase in the thermal load during defrosting of the evaporator 41 can be suppressed, and the temperature inside the refrigerator can be easily maintained.

[0109] [Variations] 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 rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0110] For example, in the above first to fourth embodiments, the cooling devices 100, 200, 300, and 400 are vertical showcases, but the present invention is not limited to this. For example, the cooling device may be a flat showcase that discharges cooled air in a horizontal direction to form an air curtain.

[0111] In the first to fourth embodiments, the evaporators 41 and 42 (main evaporator and sub evaporator) are arranged so as not to overlap when viewed from the direction in which the first air flow path A1 and the second air flow path A2 are adjacent to each other (the X1 direction side or the X2 direction side), but the present invention is not limited to this. In the present invention, the main evaporator and the sub evaporator may overlap when viewed from the direction in which the first air flow path and the second air flow path are adjacent to each other.

[0112] In the above first to third embodiments, the first air flow path A1 in which the evaporator 41 (main evaporator) is provided is disposed closer to the cooling space S side (X1 direction side) than the second air flow path A2 in which the evaporator 42 (sub-evaporator) is provided. That is, the first air flow path A1 in which the evaporator 41 (main evaporator) is provided and the second air flow path A2 in which the evaporator 42 (sub-evaporator) is provided are disposed in the front-rear direction (X direction) of the cooling device 100, but the present invention is not limited to this. In the present invention, the first air flow path in which the main evaporator is provided and the second air flow path in which the sub-evaporator is provided may be disposed adjacent to each other in the left-right direction (Y direction) of the cooling device, rather than in the front-rear direction (X direction).

[0113] In the fourth embodiment, the first air flow path B1 in which the evaporator 41 (main evaporator) is provided is disposed closer to the cooling space S (X1 direction side) than the second air flow path B2 in which the evaporator 42 (sub evaporator) is provided, and the mixing area M is not provided. However, the present invention is not limited to this. In the present invention, as in a cooling device 500 according to a modified example shown in FIG. 9, the second air flow path D2 in which the evaporator 42 (sub evaporator) is provided may be disposed closer to the cooling space S (X1 direction side) than the first air flow path D1 in which the evaporator 41 (main evaporator) is provided, and the mixing area M may not be provided. In the cooling device 500, the air flow path between the intake port 91 (blower fan 43) and the discharge port 92 is divided by a dividing member 593 into the first air flow path D1 in which the evaporator 41 is provided and the second air flow path D2 in which the evaporator 42 is provided. In the cooling device 500, the evaporator 41 is disposed above (on the Z1 direction side) the evaporator 42. Furthermore, in the cooling device 500, similarly to the first to fourth embodiments, the temperature of the refrigerant flowing through the evaporator 42 during the second cooling operation (during the defrosting operation of the evaporator 41) is configured to be lower than the temperature of the refrigerant flowing through the evaporator 41 and lower than the temperature of the refrigerant flowing through the evaporator 42 during the first cooling operation (during the cooling operation of the evaporator 41). As a result, the second air flow path D2 in which the evaporator 42 is provided is disposed closer to the cooling space S side (on the X1 direction side) than the first air flow path D1 in which the evaporator 41 is provided, so that the evaporator 42, whose temperature of the refrigerant flowing through it is lower than the temperature of the refrigerant flowing through the evaporator 41, can be disposed on the cooling space S side during the second cooling operation (during the defrosting operation of the evaporator 41). As a result, the cooling temperature of the cooling space S (inside the storage unit) during the second cooling operation (during the defrosting operation of the evaporator 41) can be efficiently maintained.

[0114] In the above first embodiment, the dividing member 95 that divides the air flow path between the mixing region M and the discharge port 92 (discharge section) into the outer air flow path A5 and the inner air flow path A4 includes the wall portion 95a, but the present invention is not limited to this. In the present invention, a wall portion provided to block a portion of the air flowing out from the first air flow path and the second air flow path to be mixed by the mixing region, and a dividing member for dividing the air flow path between the mixing region and the discharge section may be provided separately.

[0115] In the first to third embodiments, an example is shown in which the induction section 94b is provided to induce the air flowing out from each of the first air flow path A1 and the second air flow path A2 to the mixing region M, but the present invention is not limited thereto. In the present invention, the induction section may be configured to induce the air flowing out from the first air flow path of the first air flow path and the second air flow path to the mixing region. As a result, the induction section 94b induces the air flowing out from the first air flow path to the mixing region, so that the air flowing out from each of the first air flow path and the second air flow path can be mixed more efficiently in the mixing region. In the present invention, the induction section may be configured to induce the air flowing out from the second air flow path of the first air flow path and the second air flow path to the mixing region. As a result, the induction section 94b induces the air flowing out from the second air flow path to the mixing region, so that the air flowing out from each of the first air flow path and the second air flow path can be mixed more efficiently in the mixing region.

[0116] In the above first to third embodiments, an example was shown in which a dividing member 95 was provided to divide the air flow path between the mixing region M and the discharge port 92 (discharge section) into an outer air flow path A5 and an inner air flow path A4 that is disposed closer to the cooling space S than the outer air flow path A5, but the present invention is not limited to this. The present invention may be configured without providing a dividing member for dividing the air flow path between the mixing region and the discharge section, and the air mixed by the mixing region may be discharged directly from the discharge section without being branched.

[0117] In the first to fourth embodiments, the evaporator 42 (sub-evaporator) is configured to have a larger heat transfer area than the evaporator 41 (main evaporator), but the present invention is not limited to this. In the present invention, the heat transfer area of ​​the sub-evaporator may be smaller than the heat transfer area of ​​the main evaporator, or the heat transfer areas of the main evaporator and the sub-evaporator may be approximately the same.

[0118] In the above first embodiment, the temperature sensor 62 is provided on the outer surface 42a of the evaporator 42 (sub-evaporator), but the present invention is not limited to this. In the present invention, a temperature sensor that detects the temperature of the air cooled by the sub-evaporator may be provided downstream of the sub-evaporator (second air flow path) and separated from the sub-evaporator.

[0119] In the above-described first embodiment, an example has been described in which one evaporator 41 (main evaporator) is provided in the first air flow path A1, but the present invention is not limited to this. In the present invention, a plurality of main evaporators (two or more) may be provided in the first air flow path.

[0120] In the above-described first embodiment, an example has been shown in which one evaporator 42 (sub-evaporator) is provided in the second air flow path A2, but the present invention is not limited to this. In the present invention, a plurality of sub-evaporators (two or more) may be provided in the second air flow path. [Explanation of symbols]

[0121] 10 Compressor 20 Condenser 41 Evaporator (main evaporator) 42 Evaporator (secondary evaporator) 61, 261 Temperature sensor 80 Back plate 80a Rear blowhole 92 Discharge port (discharge part) 92a Inner outlet (inner outlet) 92b Outside discharge port (outside discharge part) 93a, 94a, 493a Slope section 94b Guidance part 95 Partitioned parts 95a wall 100, 200, 300, 400, 500 chillers 394c Discharge hole (horizontal discharge hole) A1, B1, D1 First air flow path A2, B2, D2 Second air flow path A3 Rear air passage A4 Inner air passage A5 Outer air passage C1 Inner air curtain (inner air curtain) C2 Outer Air Curtain M mixed area S cooling space

Claims

1. A compressor that compresses a refrigerant; a condenser that condenses the refrigerant discharged from the compressor; a main evaporator and a sub evaporator for evaporating the refrigerant condensed by the condenser; a first air flow path in which the main evaporator is disposed; the sub-evaporator is provided therein, and a second air flow path is provided separately from the first air flow path; The main evaporator is configured to be switched between a cooling operation and a defrosting operation, During a cooling operation of the main evaporator provided in the first air flow path, a cooling space in which a commodity is stored is cooled in a state in which a temperature of the refrigerant flowing through the sub-evaporator provided in the second air flow path is set higher than a temperature of the refrigerant flowing through the main evaporator and a temperature at which frost forms on the sub-evaporator, The cooling device further includes a mixing region that mixes the air flowing out of the first air flow path and the air flowing out of the second air flow path.

2. The cooling device according to claim 1 , wherein the main evaporator and the sub-evaporator are arranged so as not to overlap each other when viewed from a direction in which the first air flow path and the second air flow path are adjacent to each other.

3. 3. The cooling device according to claim 1, wherein the first air flow passage in which the main evaporator is provided is disposed closer to the cooling space than the second air flow passage in which the sub-evaporator is provided.

4. a discharge portion that discharges air cooled by the main evaporator and the sub-evaporator; A rear air flow path is provided on a rear side of the cooling space and between the cooling space and the first air flow path, The cooling device according to any one of claims 1 to 3, wherein the mixing area mixes the air flowing out of the first air flow path and the air flowing out of the second air flow path, and distributes the mixed air to the discharge side flow path and the rear air flow path.

5. 2. The cooling device according to claim 1, further comprising a wall portion provided downstream of the mixing area so as to block a portion of the air flowing out of the first air flow path and the second air flow path that is mixed by the mixing area.

6. The cooling device according to claim 1 , further comprising an induction section for guiding the air flowing out of at least one of the first air flow path and the second air flow path to the mixing region.

7. a dividing member for dividing an air flow path between the mixing region and the discharge portion into an outer air flow path and an inner air flow path disposed closer to the cooling space than the outer air flow path, the discharge section is configured to discharge cooled air from above downward, and includes an inner discharge section provided in communication with the inner air flow path for forming an inner air curtain that blocks the cooling space from outside air, and an outer discharge section provided in communication with the outer air flow path for forming an outer air curtain outside the inner air curtain that blocks the cooling space from outside air, The cooling device according to claim 4 , wherein the outer air flow path and the second air flow path are provided outside the cooling space relative to the inner air flow path and the first air flow path, respectively.

8. a plate-shaped rear plate that is provided on the rear side of the cooling space and between the cooling space and the rear air flow passage so as to extend in a vertical direction, and has rear air blowing holes for discharging the air mixed in the mixing area from the rear air flow passage toward the cooling space in a horizontal direction; 5. The cooling device according to claim 4, further comprising a horizontal discharge hole for discharging the air cooled by the main evaporator in the first air flow path from the first air flow path toward the rear air flow path along a horizontal direction.

9. a temperature of the refrigerant flowing through the sub-evaporator during a defrosting operation of the main evaporator is made lower than a temperature of the refrigerant flowing through the main evaporator during a cooling operation of the main evaporator, 9. The cooling device according to claim 1, wherein the sub-evaporator is configured to have a larger heat transfer area than the main evaporator.

10. The first air flow path and the second air flow path are formed to extend in a vertical direction so that the air to be cooled flows from below to above, The cooling device according to any one of claims 1 to 9, further comprising an inclined portion inclined inwardly as it extends upward, above the main evaporator in the first air flow path.

11. The cooling device according to any one of claims 1 to 10, further comprising a temperature sensor provided in at least one of a downstream side of the main evaporator and an outer surface of the main evaporator in the first air flow path, for detecting a temperature.

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