JP6689376B2 - Cooling unit - Google Patents

Description

  The present invention relates to a cooling unit having a heater arranged below a drain pan.

  Conventionally, a technique for removing frost attached to an evaporator is known. For example, in the conventional technique described in Patent Document 1, hot gas discharged from a compressor is caused to flow through an evaporator to perform hot gas defrosting for removing frost attached to the evaporator (for example, Patent Document 1). Reference 1).

JP-A-63-169458

  However, the conventional technique as described in Patent Document 1 has a problem that frost cannot be removed efficiently. This is because the air that has been warmed by exchanging heat with the hot gas that flows to the evaporator expands and its density decreases, so in the space where the evaporator is housed, warm air gathers on the upper side and cool air on the lower side. Gather. Therefore, the heat of the air in the space in which the evaporator is housed cannot be efficiently used to remove the frost.

  The present invention has been made in view of the above problems, and an object thereof is to obtain a cooling unit capable of efficiently defrosting an evaporator.

The cooling unit according to the present invention is arranged at least below the evaporator and the evaporator of a refrigerant circuit formed by connecting a compressor, a condenser, an expansion device and an evaporator with a refrigerant pipe. A drain pan, a heater disposed below the drain pan, for heating, a cover for covering at least a part of the heater together with the drain pan, a casing accommodating at least the evaporator, and a rear surface formed. a suction port for sucking air is formed on the front surface, e Preparations and outlet for blowing air, and to the casing or the cover, with aeration to the heater, and at least a pair of vent holes are formed, One of the pair of ventilation holes is formed on a surface corresponding to the back surface, and the other is formed on a surface corresponding to the front surface.

  According to the present invention, the drain pan heated by the heater heats the evaporator from below the evaporator, so that the evaporator can be efficiently defrosted.

It is the figure which described typically the refrigerating cycle device in which the evaporator concerning Embodiment 1 of this invention is arranged. It is the figure which described typically the state which looked at the cooling unit which accommodated the evaporator shown in FIG. 1 from diagonally. FIG. 3 is a diagram schematically illustrating an AA cross section of FIG. 2. FIG. 4 is a diagram schematically showing a state in which the drain pan and the heater shown in FIG. 3 are viewed from below. It is the figure which described typically the state which looked at the cover shown in FIG. 3 from diagonally.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference numerals, and the description thereof will be appropriately omitted or simplified. Further, regarding the configuration shown in each drawing, the shape, size, arrangement and the like can be appropriately changed within the scope of the present invention.

[Refrigeration cycle device]
Embodiment 1.
FIG. 1 is a diagram schematically showing a refrigeration cycle device in which an evaporator according to a first embodiment of the present invention is arranged. As shown in FIG. 1, the refrigeration cycle apparatus 1 is formed to include a refrigerant circuit 2 and a hot gas passage 4. Refrigeration cycle device 1 is filled with a refrigerant. The refrigerant used in the refrigeration cycle apparatus 1 of this embodiment is, for example, a refrigerant having a low global warming potential (GWP) such as R410A, R32, or CO2, and a mixture containing at least one of these. It may be a refrigerant or another type of refrigerant different from these.

[Refrigerant circuit]
The refrigerant circuit 2 circulates the refrigerant, and is formed by connecting the compressor 10, the condenser 12, the expansion device 14, and the evaporator 16 with the refrigerant pipe 3. The compressor 10 compresses a refrigerant. The compressor 10 is, for example, an inverter compressor that is controlled by an inverter, and can change the capacity (amount of refrigerant discharged per unit time) by arbitrarily changing the operating frequency. The compressor 10 may be a constant speed compressor that operates at a constant operating frequency. The condenser 12 is, for example, a heat exchanger that exchanges heat between the refrigerant flowing through the condenser 12 and air, and condenses the refrigerant. For example, the condenser 12 is a fin-tube heat exchanger including a tube (not shown) through which the refrigerant flows and fins (not shown) attached to the tube. A blower (not shown) that blows air to the condenser 12 is disposed near the condenser 12. The expansion device 14 expands the refrigerant and is, for example, an electronic expansion valve whose opening can be adjusted, but may be a device such as a capillary tube whose opening cannot be adjusted.

  The evaporator 16 is a heat exchanger for exchanging heat between the refrigerant flowing through the evaporator 16 and the air, and evaporates the refrigerant. For example, the evaporator 16 is a fin-tube heat exchanger including a tube (not shown) through which the refrigerant flows and fins (not shown) attached to the tube. A blower (not shown in FIG. 1) that blows air to the evaporator 16 is disposed near the evaporator 16. Further, a distributor 15 and a header 17 are connected to the evaporator 16. The distributor 15 distributes the refrigerant expanded by the expansion device 14 and causes the refrigerant to flow into the evaporator 16. The header 17 joins the refrigerant evaporated by the evaporator 16 and flowing out from the evaporator 16. Below the evaporator 16, a drain pan 104 that receives water and the like dropped from the evaporator 16 is arranged.

[Operation of refrigerant circuit]
Next, the operation of the refrigerant circuit 2 will be described. The refrigerant compressed by the compressor 10 is condensed by the condenser 12. The refrigerant condensed in the condenser 12 is expanded in the expansion device 14. The refrigerant expanded in the expansion device 14 is evaporated in the evaporator 16. The refrigerant evaporated in the evaporator 16 is sucked into the compressor 10 and compressed again.

[Hot gas path]
The hot gas passage 4 allows the high-temperature and high-pressure refrigerant compressed by the compressor 10 to flow to the evaporator 16. The hot gas passage 4 includes a hot gas bypass pipe 6 and an opening / closing valve 18. The hot gas bypass pipe 6 is a pipe that bypass-connects between the discharge part of the compressor 10 and the condenser 12, and between the expansion device 14 and the evaporator 16. For example, the hot gas bypass pipe 6 branches from between the discharge part of the compressor 10 and the condenser 12, passes through the vicinity of the drain pan 104, and then joins between the expansion device 14 and the evaporator 16. A portion of the hot gas bypass pipe 6 that passes near the drain pan 104 forms a heater 106 that heats the drain pan 104. A portion of the hot gas bypass pipe 6 connected between the expansion device 14 and the evaporator 16 is connected to the distributor 15. The on-off valve 18 is disposed in the hot gas bypass pipe 6 and controls the inflow of the refrigerant into the hot gas passage 4 by opening and closing. The opening / closing valve 18 is, for example, an opening / closing switching valve that simply switches between opening and closing, but may be an electric valve or the like that can adjust the opening. The on-off valve 18 may be provided in a pipe of the hot gas bypass pipe 6 that branches from between the discharge part of the compressor 10 and the condenser 12 and approaches the drain pan 104.

[Operation of hot gas passage]
If frost adheres to the evaporator 16, the efficiency of heat exchange of the evaporator 16 deteriorates. Therefore, in the example of this embodiment, the frost adhering to the evaporator 16 is removed by causing the hot gas refrigerant to flow through the hot gas passage 4 to heat the evaporator 16. That is, when the on-off valve 18 is opened, the high-temperature and high-pressure refrigerant compressed by the compressor 10 flows into the hot gas bypass pipe 6. The refrigerant flowing through the hot gas bypass pipe 6 passes near the drain pan 104, heats the drain pan 104, and then flows into the evaporator 16. The refrigerant flowing through the evaporator 16 heats the evaporator 16 and removes the frost attached to the evaporator 16. When the refrigerant flows through the hot gas passage 4, the expansion device 14 may be closed or the expansion device 14 may be opened.

[Cooling unit]
FIG. 2 is a diagram schematically showing a state in which the cooling unit accommodating the evaporator shown in FIG. 1 is viewed obliquely, and FIG. 3 is a diagram schematically showing the AA cross section of FIG. 4 is a diagram schematically showing a state in which the drain pan and the heater shown in FIG. 3 are seen from below, and FIG. 5 is a diagram showing a state in which the cover shown in FIG. 3 is seen obliquely. FIG. The cooling unit 100 shown in FIG. 2 is arranged inside a room to cool the room. The cooling unit 100 has, for example, a mounting portion 103 that is mounted on the ceiling of the room in which the cooling unit 100 is arranged, and is suspended from the ceiling of the room. The room in which the cooling unit 100 is installed is, for example, a freezer warehouse controlled at 0 to minus 35 degrees Celsius.

  As shown in FIG. 3, the cooling unit 100 includes a casing 102, an evaporator 16, a drain pan 104, a heater 106, a cover 108, a blower 110, a hood 112, and a damper 114. . The casing 102 is a housing that houses the evaporator 16 and the blower 110. A suction port 102A for sucking air is formed on the back surface of the casing 102, and a blowout port 102B for blowing air is formed on the front surface of the casing 102. For example, the cooling unit 100 is arranged so that the suction port 102A is closer to the wall surface than the blowout port 102B, but is arranged so that the blowout port 102B is closer to the wall surface than the suction port 102A. It may have been done. The air sucked from the suction port 102A is cooled by the evaporator 16, and the conditioned air cooled by the evaporator 16 is blown out from the blowout port 102B. A hood 112 is attached to the suction port 102A. The hood 112 covers a portion other than below the suction port 102A. Since the hood 112 is attached to the suction port 102A, air is sucked in from below the suction port 102A. The blower outlet 102B is provided with a damper 114 that opens and closes the blower outlet 102B. The damper 114 is in an open state when the blower 110 operates and blows air, and is in a closed state when the blower 110 is stopped and blowing is stopped.

  The drain pan 104 is disposed below the evaporator 16 and receives water and the like dropped from the evaporator 16. The heater 106 is disposed below the drain pan 104 and performs heating. In the example of this embodiment, as shown in FIGS. 1 and 4, the heater 106 is formed to include a part of the hot gas bypass pipe 6. Specifically, as shown in FIG. 4, the hot gas bypass pipe 6 has a distribution header 160 for distributing the refrigerant and a plurality of unit flow paths 162 for flowing the refrigerant distributed in the distribution header 160, in the middle thereof. And a merging header 164 for merging the refrigerants flowing out from the plurality of unit flow paths 162. The heater 106 is formed to include a distribution header 160, a plurality of unit channels 162, and a confluence header 164. In the example of this embodiment, since the heater 106 is formed to include a plurality of unit flow paths 162 between the distribution header 160 and the confluence header 164, the evaporator 16 can be efficiently defrosted. You can This is because, by adopting a configuration having a plurality of unit channels 162, it is possible to shorten the length of each of the plurality of unit channels 162 and increase the area of the unit channels 162 that are in contact with the drain pan 104. Since the length of the unit flow path 162 is shortened, the temperature of the refrigerant passing through the unit flow path 162 is prevented from being excessively lowered, so that the removal of the evaporator 16 performed using the refrigerant flowing through the evaporator 16 is performed. Frost can be performed efficiently. Further, since the area of the unit flow path 162 in contact with the drain pan 104 is increased, it is possible to efficiently defrost the evaporator 16 by heating the drain pan 104.

  The unit channel 162 is attached in contact with the lower surface that forms a part of the outer surface of the drain pan 104. The unit channel 162 is sandwiched between the fixed plate 166 and the lower surface of the drain pan 104 by using the plurality of fixed plates 166. The unit channel 162 is sandwiched between the fixed plate 166 and the lower surface of the drain pan 104, whereby the heat of the refrigerant flowing through the unit channel 162 is efficiently transmitted to the drain pan 104. The fixing plate 166 may be formed of a material having high thermal conductivity such as metal.

  As shown in FIGS. 2 and 3, the cover 108 covers at least a part of the heater 106 together with the drain pan 104. As shown in FIGS. 2 to 5, in the example of this embodiment, the distribution header 160, the unit channel 162, and the merging header 164 are housed in the space covered by the drain pan 104 and the cover 108. Since the distribution header 160, the unit channel 162, and the confluence header 164 are housed in the space covered by the drain pan 104 and the cover 108, the design of the cooling unit 100 is improved. Further, in the example of this embodiment, since the heater 106 is covered with the drain pan 104 and the cover 108, the heater 106 can efficiently heat the drain pan 104. Further, since the heater 106 is covered with the drain pan 104 and the cover 108, it is possible to prevent the room from being warmed by the heat generated when the heater 106 is heated.

  As shown in FIG. 5, a plurality of pairs of vent holes 180 are formed in the cover 108. One vent hole 180A of the pair of vent holes 180 is formed on the back surface where the suction port 102A is formed, and the other vent hole 180B of the pair of vent holes 180 has the outlet port 102B formed. Is formed on the front surface. In the example of this embodiment, since at least a pair of vent holes 180 are formed in the cover 108, an air flow is generated in the space covered by the cover 108. Therefore, in the example of this embodiment, the possibility that frost will adhere to the heater 106 and the like inside the space covered by the drain pan 104 and the cover 108 is reduced. The number, size, position, shape, etc. of the pair of ventilation holes 180 are not particularly limited. That is, at least a pair of ventilation holes 180 may be covered with the drain pan 104 and the cover 108, and may be formed so as to ventilate the space in which the heater 106 is housed. As in the example of this embodiment, the ventilation holes 180 are arranged in a line, whereby the strength of the cover 108 in which the ventilation holes 180 are formed is improved, and the space in which the heater 106 is housed is improved. Aeration is performed uniformly.

  The ventilation hole 180 is formed below the unit flow path 162. Since the ventilation holes 180 are formed below the unit flow paths 162, the unit flow paths 162 have a configuration that is difficult to see, and thus the design of the cooling unit 100 can be further improved. Further, since the ventilation hole 180 is formed below the unit flow path 162, the air flow generated by the ventilation hole 180 is less likely to be blocked by the unit flow path 162. Further, since the ventilation hole 180 is formed in the lower portion of the cover 108 in the vertical direction, cold air is easily discharged to the outside of the cover 108 through the ventilation hole 180, and warm air is discharged to the cover 108. It is designed to be easily retained inside. In the example of this embodiment, the warm air is easily retained inside the cover 108, so that the drain pan 104 can be efficiently heated. Further, in the example of this embodiment, since the cool air, especially the cool air containing moisture is easily discharged from the vent hole 180 formed in the lower side of the cover 108 in the vertical direction, the heater 106 is provided. Also, the risk of freezing of the drain pan 104 and the like is suppressed. The ventilation hole 180 is formed, for example, below the center of the cover 108 in the vertical direction, but preferably, the ventilation hole 180 is located in the lower portion of the cover 108 near the bent portion. Formed in the area.

  As described above, the cooling unit 100 according to the present embodiment is provided with the evaporator 16, the drain pan 104 provided below the evaporator 16, and the heater provided with heating below the drain pan 104. 106 and a drain pan 104, and a cover 108 that covers at least a part of the heater 106. In the cooling unit 100 of the example of this embodiment, the drain pan 104 heated by the heater 106 heats the evaporator 16 from below the evaporator 16, so that the evaporator 16 can be efficiently defrosted. Further, in the cooling unit 100 of the example of this embodiment, at least a part of the heater 106 is covered with the drain pan 104 and the cover 108, so that the heater 106 can efficiently perform heating. Further, in the example of this embodiment, at least a part of the heater 106 is covered with the drain pan 104 and the cover 108, so that the temperature rise in the cooling space when the heater 106 is heated is suppressed.

  For example, the heater 106 includes at least a part of the hot gas bypass pipe 6 that bypasses the refrigerant circuit 2 between the discharge portion of the compressor 10 and the condenser 12 and between the expansion device 14 and the evaporator 16. It is formed including. In the example of this embodiment, the heater 106 heats the evaporator 16 from below the evaporator 16, and the refrigerant flowing through the hot gas bypass pipe 6 flows through the evaporator 16 to heat the evaporator 16. Therefore, the defrosting of the evaporator 16 can be efficiently performed. Furthermore, in the example of this embodiment, since the heater 106 is formed by using the hot gas bypass pipe 6, the configuration of the cooling unit 100 is simplified.

  Moreover, for example, at least a part of the hot gas bypass pipe 6 forming the heater 106 is attached to the drain pan 104 in a state of being in contact with the drain pan 104, so that the drain pan 104 can be efficiently heated.

  Further, for example, an opening / closing valve 18 arranged in the hot gas bypass pipe 6 may be further provided, and a refrigerant may flow through the hot gas bypass pipe 6 when defrosting the evaporator 16.

  Further, for example, a distributor 15 that distributes the refrigerant expanded by the expansion device 14 and causes the refrigerant to flow into the evaporator 16 is further provided. The portion of the hot gas bypass pipe 6 connected between the expansion device 14 and the evaporator 16 is connected to the distributor 15. By configuring the hot gas bypass pipe 6 to be connected to the distributor 15, the connection of the hot gas bypass pipe 6 can be ensured and the connection of the hot gas bypass pipe 6 can be facilitated.

  Further, for example, the heater 106 includes a distribution header 160 that distributes the refrigerant, a plurality of unit flow paths 162 that flow the refrigerant distributed by the distribution header 160, and a plurality of unit flow paths in the middle of the hot gas bypass pipe 6. And a merging header 164 for merging the refrigerants flowing out from 162. Since the heater 106 is formed to include the plurality of unit passages 162 between the distribution header 160 and the merge header 164, the evaporator 16 can be efficiently defrosted. This is because, by having a configuration including a plurality of unit channels 162, it is possible to shorten the length of each of the plurality of unit channels 162 and increase the area of the plurality of unit channels 162 that contacts the drain pan 104. it can. Since the length of the unit flow path 162 is shortened, the temperature of the refrigerant passing through the unit flow path 162 is prevented from being excessively lowered, so that the removal of the evaporator 16 performed using the refrigerant flowing through the evaporator 16 is performed. Frost can be performed efficiently. Furthermore, since the area of the plurality of unit flow paths 162 that contacts the drain pan 104 is increased, the drain pan 104 is efficiently heated, so that the evaporator 16 is efficiently defrosted by heating the drain pan 104. You can

  Further, for example, by covering the distribution header 160, the plurality of unit flow paths 162, and the merging header 164 with the cover 108, the design of the cooling unit 100 is improved.

  Further, for example, the casing 102 further containing at least the evaporator 16 is further provided, and at least a pair of vent holes 180 for ventilating the heater 106 are formed in the casing 102 or the cover 108. By forming the ventilation hole 180 for ventilating the heater 106, an air flow is generated in the space in which the heater 106 is housed, so that the generation of frost in the space in which the heater 106 is housed is suppressed. In the above, the example in which the vent hole 180 is formed in the cover 108 has been described, but in the case where the heater 106 is arranged in the space covered with the casing 102, the drain pan 104, and the cover 108, The ventilation hole 180 may be formed in the casing 102.

  Further, for example, at least a part of the heater 106 is arranged above the ventilation hole 180. By disposing at least a part of the heater 106 above the ventilation hole 180, the heater 106 has a configuration that is difficult to see through the ventilation hole 180, and therefore the designability is improved. Further, since the air flow generated by the ventilation holes 180 is not easily blocked by the heater 106, the possibility that frost will adhere to the heater 106 and the like covered by the drain pan 104 and the cover 108 is reduced. Further, by arranging at least a part of the heater 106 to be arranged above the ventilation hole 180, cold air can be easily discharged to the outside of the cover 108 through the ventilation hole 180, and warm air can be discharged. The drain pan 104 can be efficiently heated because it is easily held inside 108. Further, since the cool air, especially the cool air containing water is easily discharged from the ventilation hole 180, the risk that the heater 106, the drain pan 104, and the like are frozen is suppressed. In addition, for example, a portion formed above the ventilation hole 180 of the heater 106 is a plurality of unit flow paths 162 between the distribution header 160 and the merge header 164.

  Further, for example, the cooling unit 100 further includes a suction port 102A that is formed on the back surface of the cooling unit 100 and sucks air, and a blowout port 102B that is formed on the front surface of the cooling unit 100 and blows out air. Then, of the pair of ventilation holes 180, one ventilation hole 180A is formed on the surface on which the suction port 102A corresponding to the back surface is formed, and the other ventilation hole 180B corresponds to the blowing port 102B corresponding to the back surface. It is formed on the formed surface. Therefore, when the blower 110 operates, air is sucked in from the suction port 102A and air is blown out from the blowout port 102B, air flows in from the other vent hole 180B and flows out from one vent hole 180A. An air flow is created. That is, when the cooling unit 100 is performing air conditioning, an air flow easily occurs in the space where the heater 106 is arranged. For example, by providing a structure that covers the upper side of the suction port 102A and has the hood 112 that sucks air from the lower side into the suction port 102A, the above-described air flow is more easily generated.

  In addition, for example, the cooling unit 100 further includes a damper 114 that opens and closes the air outlet 102B, and the damper 114 is closed during the defrosting operation for defrosting the evaporator 16, so that the evaporator 16 is closed. Defrosting can be performed efficiently.

  Further, for example, the cooling unit 100 is hung from the ceiling, and in such a case, the above effect becomes particularly remarkable.

  The cooling unit of the present invention may have the cover 108 omitted. That is, the cooling unit of the present invention includes the evaporator 16, the drain pan 104 disposed below the evaporator 16, and the heater 106 disposed below the drain pan 104 and performing heating. 106 includes at least a part of the hot gas bypass pipe 6 that bypasses between the discharge portion of the compressor 10 and the condenser 12 of the refrigerant circuit 2 and between the expander 14 and the evaporator 16. It may have been done. When the evaporator 16 is defrosted, the refrigerant that has heated the drain pan 104 flows to the evaporator 16, so that the evaporator 16 can be efficiently defrosted.

  The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention. That is, the configuration of the above-described embodiment may be appropriately improved, or at least a part of the configuration may be replaced with another configuration. Furthermore, the constituent elements that are not particularly limited in the arrangement are not limited to the arrangement disclosed in the embodiment, and can be arranged in a position that can achieve the function.

  For example, in the above-described embodiment, an example in which the heater 106 is formed to include the hot gas bypass pipe 6 has been described, but the heater 106 is formed to include other components such as a heating wire. May be.

  Further, for example, in the above-described embodiment, an example has been described in which the opening / closing valve 18 is switched to switch the circulation of the refrigerant to the hot gas passage 4, but the opening / closing valve 18 is omitted. You can also

  1 refrigeration cycle device, 2 refrigerant circuit, 3 refrigerant pipe, 4 hot gas passage, 6 hot gas bypass pipe, 10 compressor, 12 condenser, 14 expander, 15 distributor, 16 evaporator, 17 header, 18 open / close valve , 100 cooling unit, 102 casing, 102A inlet, 102B outlet, 103 mounting part, 104 drain pan, 106 heater, 108 cover, 110 blower, 112 hood, 114 damper, 160 distribution header, 162 unit flow path, 164 confluence header 166 fixing plate, 180 ventilation hole, 180A ventilation hole, 180B ventilation hole.

Claims (12)

A compressor, a condenser, an expansion device, and an evaporator, and a refrigerant circuit formed by connecting refrigerant pipes, at least the evaporator,
A drain pan disposed below the evaporator,
A heater arranged below the drain pan for heating,
With the drain pan, a cover that covers at least a portion of the heater,
A casing containing at least the evaporator;
A suction port that is formed on the back and sucks in air,
An outlet formed on the front and blowing out air,
Equipped with
In the casing or the cover, at least a pair of ventilation holes for performing ventilation to the heater are formed,
Of the pair of vent holes, one is formed on a surface corresponding to the back surface, and the other is formed on a surface corresponding to the front surface,
Cooling unit. The heater is formed by including at least a part of a hot gas bypass pipe that bypasses between the discharge portion of the compressor and the condenser of the refrigerant circuit and between the expansion device and the evaporator. Has been
The cooling unit according to claim 1. At least a part of the hot gas bypass pipe is attached to the drain pan while being in contact with the drain pan.
The cooling unit according to claim 2. Further comprising an on-off valve arranged in the hot gas bypass pipe,
The cooling unit according to claim 2 or 3. Further comprising a distributor that distributes the refrigerant expanded by the expansion device to flow into the evaporator,
A portion of the hot gas bypass pipe connected between the expansion device and the evaporator is connected to the distributor.
The cooling unit according to any one of claims 2 to 4. The heater, in the middle of the hot gas bypass pipe, a distribution header for distributing the refrigerant, a plurality of unit channels for flowing the refrigerant distributed in the distribution header, and a refrigerant flowing out of the plurality of unit channels. Including a merge header to merge,
The distribution header, the plurality of unit flow paths, and the merging header are covered with the cover,
The cooling unit according to any one of claims 2 to 5. At least a portion of the heater is disposed above the vent hole,
The cooling unit according to claim 6. The heater is disposed in the hot gas bypass pipe, a distribution header for distributing the refrigerant, a plurality of unit flow paths for flowing the refrigerant distributed by the distribution header, and a refrigerant flowing out of the plurality of unit flow paths. It includes a merge header to merge,
At least one of the unit flow paths is formed above the ventilation hole,
The cooling unit according to any one of claims 2 to 5. Further comprising a hood attached to a surface corresponding to the back surface, covering an upper portion of the suction port, and allowing the suction port to suck air from below,
The cooling unit according to claim 1. Further comprising a damper attached to a surface corresponding to the front surface to open and close the air outlet,
The cooling unit according to claim 9. During the defrosting operation for defrosting the evaporator, the damper is closed.
The cooling unit according to claim 10. Suspended from the ceiling,
The cooling unit according to any one of claims 1 to 11.

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