JP2017150697A - Cooling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a time required for a defrosting operation.SOLUTION: A cooling apparatus comprises: a cooling unit 21 having an outside heat exchanger 33 performing heat exchange between a refrigerant and ambient air, an inside heat exchanger 35 installed in an air passage 12 through which internal air of a storage chamber 11 passes and performing heat exchange between the refrigerant and internal air, expansion mechanisms 34 and 42 performing adiabatic expansion of the refrigerant that has passed through the outside heat exchanger 33 or the inside heat exchanger 35, and a compressor 31 for compressing the refrigerant that has passed through the outside heat exchanger 33 or the inside heat exchanger 35; and a control part 22 in which when performing normal operation, the compressed refrigerant is circulated in the compressor 31, the outside heat exchanger 33, the expansion mechanism 34, and the inside heat exchanger 35 in this order, and when performing defrosting operation, the compressed refrigerant is circulated in the compressor 31, the inside heat exchanger 35, the expansion mechanism 42, and the outside heat exchanger 33 in this order. The control part 22, when performing the defrosting operation, stops driving of a blower fan F for circulating air between the storage chamber 11 and the air passage 12, and drives the blower fan F after the lapse of predetermined drive stop time.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a cooling device, and more particularly to a cooling device applied to an open flat type ice case that stores a product such as ice cream in a state where it can be taken out.

  2. Description of the Related Art Conventionally, an open flat ice case that is stored in a state in which a product such as ice cream can be taken out is known that includes a case body and a cooling unit.

  The case main body is a rectangular heat insulating casing having an opening (hereinafter also referred to as an upper opening) formed on the upper surface, and has a storage and an air passage. The storage is a room provided in a manner facing the top opening, and stores goods.

  The air passage is formed so as to be separated from the storage, and communicates with the storage through the suction port and the outlet. A blower fan is provided in the air passage. The blower fan, when driven, sucks the internal air of the storage through the air inlet into the air passage, passes through the air passage, and then blows out into the storage through the outlet. The internal air is circulated between the two.

  The cooling unit is configured by connecting an evaporator, a compressor, a condenser, and an expansion mechanism to a refrigerant pipe. The evaporator is provided in the air passage.

  The compressor is provided in a machine room inside the case body and outside the storage and the air passage. When the compressor is driven, it sucks and compresses the refrigerant that has passed through the evaporator. The condenser is provided in the machine room and condenses the refrigerant compressed by the compressor. The expansion mechanism is provided in the machine room and adiabatically expands the refrigerant condensed in the condenser and sends it to the evaporator.

  In such a cooling unit, when the compressor is driven, the refrigerant adiabatically expanded by the expansion mechanism is supplied to the evaporator. Thus, the evaporator causes heat exchange between the supplied refrigerant and the internal air passing through the air passage, and cools the internal air by evaporating the refrigerant. Thereby, the internal air of a storage is cooled and the goods stored in this storage are cooled.

  In the ice case, since the internal air passing through the air passage contains moisture, frost adheres to the evaporator when the internal air of the storage is cooled, so that the frost is removed. The frost operation is appropriately performed (for example, refer to Patent Document 1).

JP-A-6-42855

  By the way, although not explicitly disclosed in Patent Document 1, when performing a defrosting operation in an ice case, the air heated by the heater is driven by the heater disposed in the air passage. Generally, the blower fan is driven so as to pass through.

  However, in the above defrosting operation, it is necessary to prevent the temperature of the product stored in the storage from rising and the quality of the product from being deteriorated. It is necessary to limit to some extent, resulting in an increase in the time required for the defrosting operation.

  An object of this invention is to provide the cooling device which can aim at shortening of the time which a defrost operation requires in view of the said situation.

  In order to achieve the above object, a cooling device according to the present invention includes a first heat exchanger that exchanges heat between a supplied refrigerant and outside air that passes around, and an air passage through which internal air of a target chamber passes. And a second heat exchanger for exchanging heat between the supplied refrigerant and the passing internal air, and expansion for adiabatically expanding the refrigerant that has passed through the first heat exchanger or the second heat exchanger. When performing a normal operation with a cooling unit configured by connecting a mechanism and a compressor that sucks and compresses the refrigerant that has passed through the first heat exchanger or the second heat exchanger with a refrigerant pipe When the internal air is cooled and the defrosting operation is performed by circulating the refrigerant compressed by the compressor in the order of the first heat exchanger, the expansion mechanism, and the second heat exchanger. In the second heat exchange, the refrigerant compressed by the compressor is used. And a control device that removes frost adhering to the second heat exchanger by reversely circulating the expansion mechanism and the first heat exchanger in this order. When performing the defrosting operation, the driving of the blowing means for blowing and circulating the air between the target chamber and the air passage is stopped, and a predetermined drive stop time has elapsed from the start of the reverse circulation. Or after the internal temperature of the target chamber reaches a predetermined reference temperature, the air blowing means is driven.

  In the cooling device, the control unit drives a heating unit disposed in the vicinity of the second heat exchanger when the defrosting operation is performed.

  According to the present invention, when the control means performs the defrosting operation, the refrigerant compressed by the compressor is reversely circulated in the order of the second heat exchanger, the expansion mechanism, and the first heat exchanger. Since the driving of the air blowing means that blows and circulates air to and from the air passage is stopped, the ambient temperature including the second heat exchanger can be raised in a relatively short time, and the second heat exchanger Adhering frost can be removed. Then, the control means drives the air blowing means after a predetermined drive stop time has elapsed from the start of the reverse circulation or after the internal temperature of the target chamber has reached the predetermined reference temperature. Air can be circulated between the target chamber and the air passage before the drive is stopped due to a high pressure abnormality or the like. Thereby, while being able to melt the frost etc. which adhered to the air passage around the 2nd heat exchanger, it can control that a compressor stops driving. Therefore, it is possible to shorten the time required for the defrosting operation.

FIG. 1 is a longitudinal sectional view showing a longitudinal section of an ice case to which a cooling device according to an embodiment of the present invention is applied. FIG. 2 is a conceptual diagram showing some of the components of the cooling device shown in FIG. FIG. 3 is a block diagram schematically showing a control system of the cooling device. FIG. 4 is a flowchart showing the processing content of the defrosting control process performed by the control unit shown in FIG.

  Hereinafter, preferred embodiments of a cooling device according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a longitudinal sectional view showing a longitudinal section of an ice case to which a cooling device according to an embodiment of the present invention is applied. The ice case illustrated here includes a case body 10.

  The case body 10 is a rectangular heat insulating housing having an opening 10a (hereinafter also referred to as an upper surface opening) 10a formed on the upper surface. The case body 10 has a storage chamber (target chamber) 11 and an air passage 12 defined therein, and is provided with a cooling device 20.

  The storage chamber 11 is a chamber defined so as to face the upper surface opening 10a, and is for storing a basket-like object having a mesh structure in which a product such as ice cream is stored. A suction port 13 is formed in the upper rear portion of the storage chamber 11, and an air outlet 14 is formed in the upper front portion of the storage chamber 11.

  The suction port 13 is an opening for sucking air inside the storage chamber 11 and extends along the left-right direction of the storage chamber 11. The air outlet 14 is an opening for blowing air into the storage chamber 11. The air outlet 14 extends in the left-right direction of the storage chamber 11.

  The air passage 12 is an air passage from the inlet 13 to the outlet 14. The air passage 12 communicates with the suction port 13 and is outside the storage chamber 11 and behind the rear passage 12a. The lower passage 12b is outside the storage chamber 11 and below it, and the storage chamber. 11 is configured in such a manner that a front passage 12c that is outside and in front of the communication port 11 and communicates with the air outlet 14 is communicated with each other.

  FIG. 2 is a conceptual diagram showing some of the components of the cooling device 20 shown in FIG. 1, and FIG. 3 is a block diagram schematically showing a control system of the cooling device 20. As shown in FIGS. 2 and 3, the cooling device 20 includes a cooling unit 21 and a control unit (control means) 22.

  The cooling unit 21 includes a refrigerant circuit 30 and a blower fan (blower unit) F. The refrigerant circuit 30 has a main path 30a, a high-pressure refrigerant introduction path 30b, a heat radiation path 30c, and a bypass path 30d, and the refrigerant is sealed inside.

  The main path 30a includes a compressor 31, a three-way valve 32, an external heat exchanger (first heat exchanger) 33, a first expansion mechanism 34, and an internal heat exchanger (second heat exchanger) 35 through a refrigerant pipe. 36 is appropriately connected.

  The compressor 31 is disposed in the machine chamber 15 of the case body 10 as shown in FIG. The compressor 31 is driven in accordance with a command given from the control unit 22. When driven, the compressor 31 sucks the refrigerant and compresses the sucked refrigerant into a high-temperature and high-pressure state (high-temperature and high-pressure refrigerant). To be discharged.

  The three-way valve 32 has one inlet 32 a and two outlets (first outlet 32 b and second outlet 32 c), and the inlet 32 a and the first outlet 32 b according to a command given from the control unit 22. Is a switching valve that can be switched to either a first delivery state that communicates with the second delivery state or a second delivery state that communicates the inlet 32a and the second outlet 32c. A refrigerant pipe 36 connected to the compressor 31 is connected to the inlet 32 a of the three-way valve 32.

  As shown in FIG. 1, the external heat exchanger 33 is disposed in the machine room 15 like the compressor 31. The outside heat exchanger 33 exchanges heat between the refrigerant passing through and the outside air passing through the surroundings. An outside fan (not shown) is provided in the vicinity of the outside heat exchanger 33. The refrigerant line 36 connected to the inlet of the external heat exchanger 33 is connected to the first outlet 32 b of the three-way valve 32.

  As shown in FIG. 1, the first expansion mechanism 34 is disposed in the machine room 15 in the same manner as the compressor 31 and the external heat exchanger 33. The first expansion mechanism 34 is composed of, for example, an electronic expansion valve, a capillary tube, or the like, and depressurizes the refrigerant that has passed through the external heat exchanger 33 to expand adiabatically. The inlet of the first expansion mechanism 34 is connected to a refrigerant pipe 36 connected to the outlet of the external heat exchanger 33, and a high-pressure electromagnetic valve 37 is provided in the middle of the refrigerant pipe 36. The high-pressure solenoid valve 37 opens and closes in response to a command given from the control unit 22, and when opened, allows passage of refrigerant from the external heat exchanger 33 to the first expansion mechanism 34, In the case of closing, the passage of the refrigerant from the external heat exchanger 33 to the first expansion mechanism 34 is restricted.

  The internal heat exchanger 35 is disposed in the air passage 12 as shown in FIG. The internal heat exchanger 35 is connected to a refrigerant pipe 36 whose inlet is connected to the outlet of the first expansion mechanism 34, and a check valve 38 is provided in the middle of the refrigerant pipe 36. . The refrigerant line 36 connected to the outlet of the internal heat exchanger 35 is connected to the inlet of the compressor 31, and a first low-pressure electromagnetic valve 39 is provided in the middle thereof. The first low-pressure solenoid valve 39 opens and closes in response to a command given from the control unit 22, and when opened, allows passage of refrigerant from the internal heat exchanger 35 to the compressor 31, In the case of closing, the passage of the refrigerant from the internal heat exchanger 35 to the compressor 31 is restricted.

  The high-pressure refrigerant introduction path 30 b has a high-pressure refrigerant pipe 40. One end of the high-pressure refrigerant pipe 40 is connected to the second outlet 32c of the three-way valve 32 and the other end is connected to the downstream side of the check valve 38 of the refrigerant pipe 36 connected to the inlet of the internal heat exchanger 35. Is joined to the first joining point P1. The high-pressure refrigerant line 40 supplies the high-pressure refrigerant compressed by the compressor 31 to the internal heat exchanger 35 when introduction of the refrigerant is permitted by the three-way valve 32.

  The heat radiation path 30 c is configured to include a heat radiation pipe 41. The heat radiation pipe 41 is branched at a first branch point P2 in the middle of the refrigerant pipe 36 connected to the outlet side of the internal heat exchanger 35, and the refrigerant between the three-way valve 32 and the external heat exchanger 33 is obtained. The refrigerant is connected to the refrigerant pipe 36 in such a manner that it merges at the second junction P3 of the pipe 36.

  A second expansion mechanism 42 and a second low-pressure electromagnetic valve 43 are provided in the middle of the heat radiation pipe 41. The second expansion mechanism 42 is configured by, for example, an electronic expansion valve, a capillary tube, or the like, and depressurizes the refrigerant passing through the heat radiating conduit 41 to adiabatically expand.

  The second low-pressure solenoid valve 43 opens and closes in response to a command given from the control unit 22. When the second low-pressure solenoid valve 43 opens, the second low-pressure solenoid valve 43 allows the refrigerant to pass through the heat radiation pipe 41, but closes it. Controls the passage of the refrigerant through the heat radiation pipe 41.

  The bypass path 30 d includes a bypass pipe 44 and a bypass valve 45. The bypass line 44 branches from a second branch point P4 on the upstream side of the high-pressure solenoid valve 37 in the refrigerant line 36 connected to the outlet of the external heat exchanger 33, and is connected to the inlet of the compressor 31. The refrigerant pipe 36 is connected to the refrigerant pipe 36 in such a manner that it merges at the third junction P5.

  The bypass valve 45 is a valve body that can be opened and closed. When the bypass valve 45 is opened, the refrigerant allows the refrigerant to pass through the bypass pipe 44. When the bypass valve 45 is closed, the refrigerant passes through the bypass pipe 44. It regulates that.

  The blower fan F is disposed at a predetermined portion of the lower passage 12b. The blower fan F is driven in accordance with a command given from the control unit 22. When driven, the blower fan F sucks the internal air of the storage chamber 11 through the suction port 13, and sucks the sucked internal air into the rear side passage 12 a. The lower side passage 12b and the front side passage 12c pass through the air passage 12 in this order and are sent to the outlet 14 and blown out into the storage chamber 11 through the outlet 14. Air is circulated between them.

  The control unit 22 comprehensively controls the operation of each part of the cooling device 20 according to programs and data stored in the memory 23, and includes an input processing unit 22a, a determination processing unit 22b, a compressor drive processing unit 22c, a valve A drive processing unit 22d and a fan drive processing unit 22e are provided. The control unit 22 may be realized by causing a processing device such as a CPU (Central Processing Unit) to execute a program, that is, by software, or by hardware such as an IC (Integrated Circuit). However, software and hardware may be used in combination.

  The input processing unit 22a inputs a command signal given from an input unit 24 such as a remote controller or a keyboard. In the present embodiment, for example, information related to the defrost start time and information related to the defrost time given from the input unit 24 is input and then stored in the memory 23. The memory 23 stores information related to the drive stop time.

  This drive stop time is a time period for temporarily stopping the drive of the blower fan F in the defrost control process described later. This drive stop time is a time determined to sufficiently heat the internal heat exchanger 35 and its surroundings, and its upper limit is such that the compressor 31 ends before the drive stops due to a high pressure abnormality or the like. The value is determined.

  The determination processing unit 22 b measures time through a built-in clock, and determines whether the measured time has passed the drive stop time stored in the memory 23. The compressor drive processing unit 22 c gives a drive command or a drive stop command to the compressor 31 to drive or stop the compressor 31. The valve drive processing unit 22d gives a switching command to the three-way valve 32 to set the first delivery state or the second delivery state. Further, the valve drive processing unit 22d gives an open / close command to the high pressure solenoid valve 37, the first low pressure solenoid valve 39, the second low pressure solenoid valve 43, and the bypass valve 45 to open / close them. The fan drive processing unit 22e gives a drive command or a drive stop command to the blower fan F to drive or stop the blower fan F.

  In the cooling device 20 having the above-described configuration, when performing normal operation, the control unit 22 sends a drive command to the compressor 31 through the compressor drive processing unit 22c and sends air through the fan drive processing unit 22e. A drive command is sent to the fan F.

  Further, the control unit 22 gives the open command to the high pressure solenoid valve 37 and the first low pressure solenoid valve 39 while opening the three-way valve 32 through the valve drive processing unit 22d, and opens the second low pressure solenoid valve. 43 and the bypass valve 45 are closed by giving a close command.

  When the blower fan F is driven in this way, the internal air of the storage chamber 11 is sucked through the suction port 13 and passes through the air passage 12 in the order of the rear side passage 12a, the lower side passage 12b, and the front side passage 12c. In this manner, the air is delivered to the air outlet 14 and blown out into the storage chamber 11 through the air outlet 14. Thereby, the internal air of the storage chamber 11 can be circulated between the interior of the storage chamber 11 and the air passage 12.

  By driving the compressor 31, in the cooling unit 21, the refrigerant compressed by the compressor 31 is normally circulated as follows.

  The refrigerant compressed by the compressor 31 passes through the three-way valve 32 in the first delivery state and reaches the external heat exchanger 33 via the refrigerant pipe 36. The refrigerant that has reached the external heat exchanger 33 dissipates heat to ambient air (outside air) and condenses while passing through the external heat exchanger 33. The refrigerant condensed in the external heat exchanger 33 is adiabatically expanded by the first expansion mechanism 34 and reaches the internal heat exchanger 35, and is evaporated from the internal air passing through the air passage 12 by evaporating in the internal heat exchanger 35. Heat is taken away and the internal air is cooled. The refrigerant evaporated in the internal heat exchanger 35 is sucked into the compressor 31 and then compressed and repeatedly passes through the main path 30a.

  By performing such normal operation, the internal air circulated between the storage chamber 11 and the air passage 12 by the blower fan F is cooled by the evaporator, whereby the internal air of the storage chamber 11 is reduced. The product that is cooled and stored in the storage chamber 11 is cooled.

  And when the present time passes the defrost start time memorize | stored in the memory 23, the control part 22 implements the following defrost control processes. In addition, the compressor 31 and the ventilation fan F are demonstrated as what is driving as a premise of this defrost control process.

  FIG. 4 is a flowchart showing the processing contents of the defrosting control process performed by the control unit 22 shown in FIG.

  In this defrosting control process, the control unit 22 sends a drive stop command to the compressor 31 through the compressor drive processing unit 22c (step S101) to stop the drive of the compressor 31 and through the fan drive processing unit 22e. A drive stop command is sent to the blower fan F (step S102), and the blower fan F is stopped.

  Then, the control unit 22 sends a switching command to the three-way valve 32 through the valve drive processing unit 22d, sends an opening command to the second low pressure solenoid valve 43 and the bypass valve 45, and also sends the first low pressure solenoid valve 39 and the high pressure solenoid valve 39 to the high pressure. A close command is sent to the electromagnetic valve 37 (step S103, step S104, step S105).

  After performing the processes of steps S103 to S105, the control unit 22 sends a drive command to the compressor 31 through the compressor drive processing unit 22c (step S106) to drive the compressor 31.

  By driving the compressor 31 in this way, in the cooling unit 21, the refrigerant compressed by the compressor 31 is reversely circulated as follows.

  The refrigerant compressed by the compressor 31 passes through the high-pressure refrigerant pipe 40 via the three-way valve 32 in the second delivery state. The refrigerant that has passed through the high-pressure refrigerant pipe 40 reaches the internal heat exchanger 35. The refrigerant that has reached the internal heat exchanger 35 exchanges heat with the internal air of the air passage 12 while passing through the internal heat exchanger 35, and dissipates heat to the internal air to condense. Thereby, the air around the internal heat exchanger 35 is heated.

  The refrigerant condensed in the internal heat exchanger 35 reaches the heat radiating pipe 41, undergoes adiabatic expansion by the second expansion mechanism 42, and then reaches the external heat exchanger 33, and the ambient air is exchanged by the external heat exchanger 33. (External air) and heat exchange. The refrigerant that has passed through the external heat exchanger 33 reaches the bypass pipe 44, passes through the bypass pipe 44, is sucked into the compressor 31, and then repeatedly passes through the above-described path.

  At this time, since the driving of the blower fan F is stopped, the internal air of the storage chamber 11 is stopped from being circulated between the storage chamber 11 and the air passage 12. Therefore, the surroundings of the internal heat exchanger 35 are heated by the heat radiation of the refrigerant in the internal heat exchanger 35. Thus, although the surroundings of the internal heat exchanger 35 are heated, since air does not pass through the blower fan F, a sufficient amount of heat radiation in the internal heat exchanger 35 is not secured, and as a result, the compressor 31. The temperature of the refrigerant that is compressed and discharged from the chamber also increases. As a result, the ambient temperature including the internal heat exchanger 35 rises in a relatively short time. Thereby, the frost adhering to the internal heat exchanger 35 is melted.

  The control unit 22 that has performed step S105 starts measuring time from the time when the refrigerant recirculation in the cooling unit 21 is started through the determination processing unit 22, and waits for the drive stop time read from the memory 23 to elapse. (Step S107).

  When it is determined that the measurement time has passed the drive stop time through the determination processing unit 22b (step S107: Yes), the control unit 22 stops the time measurement by the determination processing unit 22b and the compressor drive processing unit 22c. Then, a drive stop command is sent to the compressor 31 through (step S108), and the compressor 31 is stopped.

  The control unit 22 that has stopped driving the compressor 31 in this way sends a drive command to the blower fan F through the fan drive processing unit 22e (step S109), and waits for the passage of the defrosting time read from the memory 23. (Step S110).

  When the blower fan F is driven in this way, air circulates between the storage chamber 11 and the air passage 12, thereby causing frost or the like attached to the air passage 12 around the internal heat exchanger 35. Can be melted.

  Thereafter, when the defrosting time has elapsed (step S110: Yes), the control unit 22 sends a drive stop command to the blower fan F through the fan drive processing unit 22e (step S111), and then returns the procedure. This defrost control process is terminated.

  As described above, in the cooling device 20 according to the present embodiment, when the control unit 22 performs the defrosting operation, the refrigerant compressed by the compressor 31 is converted into the internal heat exchanger 35, the second Since the drive of the blower fan F that blows and circulates air between the storage chamber 11 and the air passage 12 while circulating (reversely circulating) the expansion mechanism 42 and the external heat exchanger 33 in this order is stopped, the internal heat The ambient temperature including the exchanger 35 can be raised in a relatively short time, and frost attached to the internal heat exchanger 35 can be removed. And since the control part 22 drives the ventilation fan F after the drive stop time predetermined from the start of reverse circulation passes, it is the storage chamber 11 before the compressor 31 stops driving due to a high pressure abnormality or the like. Air can be circulated between the air passage 12. Thereby, while being able to melt the frost etc. which adhered to the air passage 12 around the internal heat exchanger 35, it can control that compressor 31 stops driving. Therefore, according to the cooling device 20, the time required for the defrosting operation can be shortened.

  Further, according to the cooling device 20, not only the internal heat exchanger 35 but also the frost around the internal heat exchanger 35 can be removed by performing the defrosting operation. The quality of the ice case applied by driving can be improved.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made.

  In the above-described embodiment, in the defrosting control process, in step S107, the blower fan F is driven after a predetermined drive stop time has elapsed from the start of reverse circulation. However, in the present invention, reverse circulation is performed. Then, the air blowing means (air blowing fan F) may be driven after the internal temperature of the target chamber (storage chamber 11) detected through the temperature detecting means reaches a predetermined reference temperature.

  In the present invention, when a heating means such as a heater is provided in the vicinity of the second heat exchanger (the internal heat exchanger 35), the heating means may be driven when performing the defrosting operation. Good. Thereby, ambient temperature including a 2nd heat exchanger can be raised in a short period, and defrosting can be performed reliably.

DESCRIPTION OF SYMBOLS 11 Storage chamber 12 Air passage 20 Cooling device 21 Cooling unit 22 Control part (control means)
Reference Signs List 23 Memory 30 Refrigerant circuit 30a Main path 30b High-pressure refrigerant introduction path 30c Heat radiation path 30d Bypass path 31 Compressor 32 Three-way valve 33 External heat exchanger (first heat exchanger)
34 First expansion mechanism 35 Internal heat exchanger (second heat exchanger)
36 Refrigerant pipe F F Blower (Blower)

Claims (2)

A first heat exchanger for exchanging heat between the supplied refrigerant and the outside air passing through the surroundings; and an air passage through which the internal air of the target chamber passes, and the supplied refrigerant and the passing internal air A second heat exchanger that exchanges heat between them, an expansion mechanism that adiabatically expands the refrigerant that has passed through the first heat exchanger or the second heat exchanger, and the first heat exchanger or the second heat exchanger. A cooling unit configured to connect a compressor that sucks and compresses the refrigerant that has passed through the refrigerant pipe,
When normal operation is performed, the internal air is cooled by circulating the refrigerant compressed by the compressor in the order of the first heat exchanger, the expansion mechanism, and the second heat exchanger, When performing the defrosting operation, the refrigerant compressed by the compressor is reversely circulated in the order of the second heat exchanger, the expansion mechanism, and the first heat exchanger, so that the second heat exchanger A cooling device comprising a control means for removing adhering frost,
When the defrosting operation is performed, the control unit stops driving the blowing unit that blows and circulates air between the target chamber and the air passage, and is determined in advance from the start of the reverse circulation. The cooling device is characterized in that the air blowing means is driven after the drive stop time has elapsed or after the internal temperature of the target chamber has reached a predetermined reference temperature.   2. The cooling device according to claim 1, wherein, when the defrosting operation is performed, the control unit drives a heating unit disposed in the vicinity of the second heat exchanger.

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