KR101608057B1 - Temperature control method for storage and transport container - Google Patents

Abstract

The present invention relates to a method for controlling the temperature of a storage container, and more particularly, to a method of controlling temperature of a storage container using a refrigerant circulating along a refrigerant pipe, the method comprising the steps of: (a) (b) cooling the refrigerant to a storage space of a storage container capable of storing the refrigerant, (c) cooling the storage space by exchanging the refrigerant with the refrigerant in the storage space, and (d) Thus, it is possible to gradually change the temperature of the storage space in which the agricultural products are received, thereby preventing the quality change of the agricultural products due to the cold weather and the condensation phenomenon.

Description

TECHNICAL FIELD [0001] The present invention relates to a temperature control method for a storage container,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling temperature of a storage container capable of accommodating agricultural products and other objects to be stored.

In recent years, there has been a growing demand for freshly distributed meat, fish, shellfish, fresh vegetables and fruits at low temperatures. In particular, in order to keep food at a low temperature, refrigeration vehicles, cold storage warehouses for refrigeration / Boxes, etc., the industry related to such a cold chain system is also continuously growing. However, unlike the outline growth of the distribution industry, the cold chain system is still in the introduction phase, and is focused on show-cases, refrigerators, refrigerators or parcel delivery type ice packs, .

Among the objects of low-temperature distribution, agricultural products are most sensitive to temperature changes. In case of using ice boxes, there is a short period of time in which fresh produce can be delivered (indicating a reduction in transportation and delivery). In addition, there is a problem that excessive power is consumed to operate the freezing / refrigerating machine when the agricultural products are transported by using the cart having the freezing / refrigerator, and after the agricultural products are taken out from the freezing / There is a problem that the agricultural products are left at room temperature during the process of transferring to the facility and the quality of the products is deteriorated.

On the other hand, a technique of utilizing a thermoelectric element for refrigeration or freezing is known. Here, a thermoelectric element is a metal element composed of a p-type semiconductor and an n-type semiconductor, and refers to a device in which a direct current is passed to generate a heat dissipation and heat dissipation of peltier, which is one of the effects of thermoelectric conversion. Korean Patent Application Laid-Open No. 10-2007-0102189 (Hereinafter referred to as "prior art") discloses a refrigerator to which a thermoelectric element is applied.

Referring to the above-mentioned prior art, a case is inserted into a storage room of a refrigerator, and the case comprises an inner case and an outer case. A cooling space is formed between the inner case and the outer case, and the cooling material is accommodated in the cooling space. The cool air generated from the thermoelectric element is blown into the inner case by a fan. Since the cool air is discharged from the coolant even if it is put outdoors by removing the case, the contents can be kept fresh for a certain period of time . However, the thermoelectric element operates only when power is supplied from the refrigerator, and the thermoelectric element does not operate at all when the case is removed and placed outdoors. As a result, in a state in which the case is placed outdoors, this prior art functions only as far as the time limit in which the heat storage material can release the cold air, unlike the conventional ice box, and thereafter the function is deteriorated. In addition, when the commercial storage material developed up to now is used, the freshness of the contents can not be maintained for 20 hours in a state where the case is separated from the prior art and placed on the outdoors.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an improved temperature control method of a storage container for preventing change in quality of agricultural products due to cold weather and condensation have.

Further, it is an object of the present invention to provide a method for controlling the temperature of a storage container which is improved to maintain the freshness of agricultural products for a long time.

According to another aspect of the present invention, there is provided a method of controlling a temperature of a storage container using a refrigerant circulating along a refrigerant pipe, the method comprising the steps of: (a) Exchanging heat between the refrigerant and the refrigerant to cool the refrigerant; (b) supplying the refrigerant to a storage space of the storage container capable of storing the refrigerant; (c) , And (d) recovering the refrigerant.

Preferably, the refrigerant comprises at least one of water and an antifreeze.

Preferably, the refrigerant comprises 50 to 90 vol% water and 10 to 50 vol% antifreeze.

Preferably, the thermoelectric element has a heat absorbing portion capable of absorbing heat and a heat generating portion capable of receiving and absorbing heat absorbed by the heat absorbing portion, wherein in the step (a), the refrigerant tube is thermally contacted with the heat absorbing portion, And the heat absorbing portion absorbs the heat of the refrigerant.

Preferably, a suction fan capable of sucking air from the outside and supplying the sucked air to the heat generating unit is provided. In the step (a), the suction fan is driven to cool the heat generating unit with air supplied from the outside.

Preferably, a discharge fan capable of sucking the air passing through the heat generating portion and discharging the air to the outside is provided, and the step (a) is performed while discharging the air that has cooled the heat generating portion to the outside by driving the discharge fan.

Preferably, a phase change material pack filled with a phase change material capable of storing heat of latent heat is provided between the refrigerant tube and the storage space. In step (c), cool air of the refrigerant is stored in the storage space To the control unit.

Preferably, a circulation fan is provided at one side of the storage space to purify the inside of the storage space, and the step (c) is performed while circulating the inside of the storage space using a circulation fan.

Preferably, a storage tank capable of receiving refrigerant is installed, wherein step (a) is performed by cooling the refrigerant discharged from the storage tank, and step (d) is performed by recovering the refrigerant having cooled the storage space to the storage tank .

The temperature control method of the storage container according to the present invention has the following effects.

First, by gradually changing the temperature of the storage space in which the agricultural products are accommodated, it is possible to prevent the quality change of the agricultural products due to the cold weather and condensation phenomenon.

Second, the freshness of the agriculture products can be preserved for a long period of time by maintaining the temperature of the storage space where the agriculture products are accommodated to the target temperature.

Third, even when the power source is shut off, the freshness of the agricultural product can be preserved by keeping the temperature of the storage space at the target temperature for a predetermined time.

1 is a partial cutaway front view of an agricultural product delivery system to which a temperature control method of a storage container according to a preferred embodiment of the present invention is applied.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of controlling a temperature of a storage container, and more particularly,
FIG. 3 is a cross-sectional view of a cooling tower provided in the agro-food delivering apparatus to which the temperature control method of the storage container according to the preferred embodiment of the present invention is applied.
FIG. 4 is a flowchart illustrating a method of controlling a temperature of a storage container according to a preferred embodiment of the present invention. Referring to FIG.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

In the drawings, the size of each element or a specific part constituting the element is exaggerated, omitted or schematically shown for convenience and clarity of description. Therefore, the size of each component does not entirely reflect the actual size. In the following description, it is to be understood that the detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, a method of adjusting the temperature of the storage container according to the present invention will be described as an example in which the food items are stored in the storage container of the storage container. However, the storage container of the storage container is not limited to agricultural products It is clear that the present invention is not necessarily limited to the use for storing agricultural products, since various storage objects such as aquatic products, livestock products, yogurt, and drinking water can be accommodated.

FIG. 1 is a partially cutaway cross-sectional view of a grocery delivery system according to a preferred embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a method of controlling a temperature of a storage container according to a preferred embodiment of the present invention. FIG. 3 is a cross-sectional view of a cooling tower provided in the agricultural product delivery system to which the temperature control method of the storage container according to the preferred embodiment of the present invention is applied.

First, the configuration of the agri-food delivery apparatus 1, which is an example of application of the temperature control method of the storage-transport vessel according to the present invention, will be described first and a temperature control method of the storage- See you.

1 to 3, the agri-food delivery apparatus 1 includes a storage transportation container 10, a refrigerant pipe 20, a phase change material pack 30, a circulation fan 40, a cooling tower 50, And may include a thermoelectric element 90, a suction fan 100, a discharge fan 110, a storage tank 60, a pump 70, a control panel (not shown), a dehumidifying fan 80, and the like.

The storage and transportation container 10 may have a storage space 10a in which the agricultural products can be received, and a lid 12 capable of opening and closing the storage space 10a. The material of the storage and transportation container 10 and the lid 12 is not particularly limited, and may be formed of, for example, a material having excellent storability or other heat insulation performance.

The refrigerant pipe 20 can regulate the temperature of the storage space 10a while circulating the refrigerant along the path and can have the first line 22, the second line 24, the third line 26, . The first line 22 is disposed along the bottom surface of the storage and transport vessel 10 and the second line 24 can be connected to the heat absorbing portion 92 of the thermoelectric element 90 to be described later, 26 may connect the first line 22 and the second line 24 to each other.

1 to 3, the refrigerant pipe 20 provides a circulation path of the refrigerant, and may be divided into a first line 22 to a third line 26 depending on the arrangement position.

The first line 22 is a line passing through the storage transportation vessel 10 and can be disposed along the bottom surface of the storage space 10a. The method of disposing the first line 22 is not particularly limited. For example, as shown in FIG. 2, the first line 22 is arranged in a zigzag manner on the bottom surface of the storage space 10a so that the surface area is increased .

The second line 24 is a line passing through the cooling tower 50 and can be connected to the heat absorbing portion 92 of the thermoelectric element 90. A pair of third lines 26 is provided and the inlet of the first line 22 between the storage and shipping container 10 and the cooling tower 50 is connected to the outlet of the second line 24 and the outlet of the first line 22 ) To the inlet of the second line 24, respectively.

Therefore, in the first line 22, heat can be exchanged between the air in the storage space 10a and the refrigerant in the first line 22, so that the temperature of the storage space 10a can be controlled. In the second line 24, the second line 24 is connected to the heat absorbing portion 92 of the thermoelectric element 90 and the refrigerant of the second line 24 and the heat absorbing portion 92 of the thermoelectric element 90 are connected to each other. The refrigerant whose temperature has risen through the first line 22 can be cooled. More detailed contents of the temperature control of the refrigerant and the storage space 10a will be described later.

On the other hand, the type of refrigerant that can be used is not particularly limited, and may include, for example, at least one of water and an antifreeze. When the water and the antifreeze are mixed and used as a refrigerant, the refrigerant may contain 50 to 90 vol% of water and 10 to 50 vol% of the antifreeze. It is most preferable to mix 90 vol% of water and 10 vol% of antifreeze solution in consideration of the temperature maintaining property of the refrigerant, but it is not limited thereto.

The phase change material pack 30 is disposed between the refrigerant tube 20 and the storage space 10a and is capable of regulating the temperature of the storage space 10a by filling a phase change material capable of storing latent heat.

Referring to FIG. 1, the phase change material pack 30 may be disposed at a lower portion of the storage space 10a so as to cover the refrigerant pipe 20. The phase change material that can be filled in the phase change material pack 30 is not particularly limited and may include, for example, at least one of C ₁₄ H ₃₀ and C ₁₈ H ₃₈ .

As the phase change material pack 30 is disposed, no heat is exchanged directly between the refrigerant in the first line 22 and the air in the storage space 10a, and indirectly through the phase change material pack 30 Heat exchange occurs. That is, the refrigerant in the first line 22 is heat-exchanged with the phase change material of the phase change material pack 30, whereby the cool air of the refrigerant can be transferred to the phase change material to be stored in the latent heat storage. In addition, the phase change material of the phase change material pack 30 is heat-exchanged with the air in the storage space 10a, so that the cool air of the phase change material is transferred to the air in the storage space 10a, Can be adjusted.

By indirectly transferring the cool air of the coolant to the air in the storage space 10a through the phase change material, even when the temperature of the coolant is abruptly changed, the temperature change of the storage space 10a due to the high heat capacity of the phase change material Progressively. Therefore, it is possible to prevent deterioration of the quality of the agricultural products housed in the storage space 10a due to the cooling and condensation phenomenon caused by the rapid temperature change of the storage space 10a.

The circulation fan 40 is installed at one side of the storage space 10a and can circulate air in the storage space 10a.

1, the circulating fan 40 may be installed on the upper surface of the storage space 10a and may discharge air toward the phase change material pack 30 provided in the lower portion of the storage space 10a . Thus, the heat exchange between the phase change material and the air in the storage space 10a can be promoted. In addition, a flow of air circulating in the clockwise direction is formed in the right side region of the storage space 10a with respect to the phase change material pack 30, and air circulated in the clockwise direction in the left side region of the storage space 10a Can be formed.

The cooling tower 50 is a cooling device for re-cooling the refrigerant whose temperature has been increased by heat exchange with the phase change material. The inside and outside of the cooling tower 50 include a storage tank 60, a pump 70, a control panel (not shown) A dehumidifying fan 80, a thermoelectric element 90, a suction fan 100, and a discharge fan 110 may be installed.

3, the internal space of the cooling tower 50 can be partitioned into a connection chamber 52a, a mechanical chamber 52b, a suction chamber, and a heat generating chamber 52d by the heat insulating partition 52 have. The connection chamber 52a is provided with a connection valve (not shown) for connecting the second line 24 and the third line 26 to the machine room 52b and a storage tank 60, a pump 70, A panel (not shown), a battery (not shown), a dehumidifying fan 80, and the like. A heat absorbing portion 92 of the thermoelectric element 90 is provided in the heat absorbing chamber 52c and a heat generating portion 94 of the thermoelectric element 90, a suction fan 100, (110) or the like may be installed.

The storage tank 60 is installed inside the machine room 52b and stores the refrigerant returned after heat exchange with the phase change material. That is, since the outlet of the first line 22 and the inlet of the second line 24 are connected to each other by the third line 26, The heat-exchanged refrigerant may be stored in the storage tank 60 through the third line 26 and through the second line 24.

The pump 70 is installed inside the machine room 52b and can discharge the refrigerant stored in the storage tank 60 at a predetermined pressure after sucking the refrigerant.

The control panel (not shown) is installed outside the machine room 52b and controls a plurality of buttons provided on a control panel (not shown) to control the overall operation of the thermoelectric elements 90 and other agricultural product water delivering apparatuses 1 .

A battery (not shown) is installed inside the machine room 52b, and can supply power necessary for driving the thermoelectric element 90 and other agricultural product water delivering apparatuses 1. The type of the battery (not shown) is not particularly limited, and a portable battery having a voltage of, for example, 12V may be used. Therefore, without supplying a separate external power supply device, it is possible to drive the agricultural product water delivering apparatus 1 using electric power supplied from a battery (not shown).

The dehumidifying fan 80 is installed on one side of the machine room 52b and discharges the air in the machine room 52b to the outside and supplies the dehumidified air to the outside through the pump 70, It is possible to discharge the heat to the outside and to remove the moisture generated in the machine room 52b.

The thermoelectric element 90 may cool the refrigerant discharged from the pump 70, and may include a heat absorbing portion 92, a heat generating portion 94, and the like. The heat absorbing part 92 absorbs heat from the refrigerant pipe 20 to adjust the temperature of the refrigerant. The heat generating part 94 can discharge the heat absorbed through the heat absorbing part 92 to the outside.

As shown in Fig. 3, the heat absorbing portion 92 is provided in the heat absorbing chamber 52c and may have a plurality of heat absorbing portion fins 92a. The heat absorbing portion fins 92a may be formed protruding from the surface of the heat absorbing portion 92 at predetermined intervals so as to increase heat transfer efficiency. 3, the second line 24 may extend from the pump 70 and enter the heat absorbing chamber 52c through the heat insulating partition wall 52 to be connected to the heat absorbing portion fin 92a. However, the present invention is not limited thereto, and the second line 24 may be directly connected to the heat absorbing portion 92.

The heat generating portion 94 is provided in the heat generating chamber 52d and may have a plurality of heat generating portion fins 94a. The heat generating part fins 94a may be formed protruding from the surface of the heat generating part 94 at predetermined intervals so as to increase the heat transfer efficiency.

As the thermoelectric element 90 is thus provided, heat exchange is performed between the heat absorbing portion 92 and the refrigerant through the second line 24. The heat absorbing portion 92 absorbs the heat of the refrigerant to lower the temperature of the refrigerant and the heat generating portion 94 receives heat absorbed from the heat absorbing portion 92 from the heat absorbing portion 82, Can be discharged.

The temperature of the refrigerant can be lowered to a predetermined target temperature by adjusting the voltage applied to the thermoelectric element 90 because the thermoelectric element 90 has a property of changing the temperature according to the applied voltage. The settable target temperature is not particularly limited, and may be set between 0 deg. C and 10 deg. C, for example, depending on the type of the agro-food product accommodated in the storage space 10a.

3, the second line 24 extends from the heat absorbing portion fin 92a again and passes through the heat insulating partition wall 52 to enter the connecting chamber 52a. In the second line 24, The outlet and the inlet of the first line 22 may be connected to each other by the third line 26. Accordingly, the first line 22, the second line 24, and the third line 26 of the refrigerant pipe 20 can form a circulation cycle of the refrigerant. That is, the refrigerant discharged from the storage tank 60 of the cooling tower 50 is cooled to the target temperature in the heat absorbing portion 92 and then supplied to the storage and transportation vessel 10 to cool the phase change material pack 30 And can be returned to the storage tank 60 again.

When the refrigerant is continuously circulated for a predetermined period of time by using the circulation structure of the refrigerant, the temperature of the phase change material pack 30 is adjusted to the target temperature by the cool air of the refrigerant, and the temperature of the storage space 10a is also changed And can be adjusted to the target temperature by the material pack 30. In addition, even when the driving of the pump 70 and the thermoelectric element 90 is stopped, cold air that has been chilled in the phase change material is released into the storage space 10a, The temperature of the storage space 10a can be maintained at the target temperature.

The suction fan 100 can suck air from the outside and supply the air to the heat generating portion 94 of the thermoelectric element 90. The exhaust fan 110 can blow air that has passed through the heat generating portion 94 of the thermoelectric element 90 It can be discharged to the outside.

3, the suction fan 100 is installed at one side of the heat generating chamber 52d so as to face the heat generating portion 94, and the discharge fan 110 is installed at the other side of the heat generating chamber 52d. Therefore, the suction fan 100 sucks outside the cooling tower 50 and supplies the sucked air to the heat generating unit 94. The exhausting fan 110 is supplied to the heat generating unit 94 to absorb heat from the heat generating unit 94 The air can be discharged to the outside of the cooling tower 50 again. As a result, heat absorbed from the refrigerant in the heat absorbing portion 92 and transferred to the heat generating portion 94 can be discharged to the outside of the cooling tower 50.

FIG. 4 is a flowchart illustrating a method of controlling a temperature of a storage container according to a preferred embodiment of the present invention. Referring to FIG.

Referring to FIG. 4, the temperature control method of the storage container according to the preferred embodiment of the present invention will be described. For convenience of description, the present invention will be described by taking the case where the target temperature of the storage space of the storage transportation container is set to 5 캜.

First, a step of cooling the refrigerant by exchanging heat between the refrigerant and the thermoelectric element 90 is performed (S 10).

The refrigerant discharged from the storage tank (60) flows along the second line (24) while being pressurized by the pump (60) at a constant pressure. Since the second line 24 is in thermal contact with the heat absorbing portion 92 of the thermoelectric element 90, heat exchange is performed between the refrigerant and the heat absorbing portion 92 via the second line 24. The heat absorbed by the heat absorbing portion 92 is transferred to the heat generating portion 94 and discharged from the heat generating portion 94. The heat absorbing portion 92 absorbs the heat of the refrigerant, do.

The suction fan 100 is driven during the heat exchange between the refrigerant and the heat absorbing part 92 to cool the heat generating part 100 with the air supplied from the outside of the cooling tower 50 to drive the discharge fan 1100, And the air cooled in the cooling tower (94) can be discharged outside the cooling tower (50).

Next, a step of supplying the refrigerant to the storage space 10a of the storage transportation container 10 capable of accommodating the agricultural products is performed (S 20).

The refrigerant cooled to 5 占 폚 is transferred from the cooling tower 50 to the storage container 10 through the third line 26 connected to the outlet of the second line 24 and then again to the outlet of the third line 26 To the storage and transport vessel (10) via the first line (22) connected to the first line (22).

Thereafter, a step of cooling the storage space 10a by exchanging the refrigerant with the inner space of the storage space 10a of the storage container 10 is performed (S30).

The refrigerant supplied to the storage and transport vessel 10 flows along the first line 22 on the bottom surface of the storage space 10a and flows through the first line 22 and the phase change material pack 30 Heat exchange is performed between the refrigerant and the inner space of the storage space 10a. That is, the cold air of the refrigerant is indirectly transferred to the storage space 10a by the phase change material pack 30 without being directly transmitted to the storage space 10a. Thus, the cold air of the cool air is transferred to the phase change material pack 30, and the phase change material pack 30 is gradually cooled to 5 DEG C due to the relatively large heat capacity of the phase change material, The storage space 10a is also gradually cooled to 5 ° C by the cool air discharged from the storage space 10a.

As described above, since the storage space 10a can be gradually cooled to the target temperature, the quality of the agricultural products housed in the storage space 10a deteriorates due to the cooling and condensation phenomenon caused by the abrupt temperature change in the storage space 10a .

 In addition, even when the supply of electric power is interrupted, the cool air that has been stored in the phase change material pack 30 is discharged to the storage space 10a, so that during a predetermined time until the phase change of the phase change material is completed, It is possible to maintain the temperature of the heat exchanger 10a at the target temperature.

Next, the step of recovering the refrigerant is performed (S40).

The refrigerant that has cooled the storage space 10a is transferred from the storage container 10 to the cooling tower 50 through the third line 26 connected to the outlet of the first line 22 and then to the third line 26 To a storage tank (60) through a second line (24) connected to the outlet of the storage tank (60). That is, the refrigerant discharged from the storage tank 60 is recovered to the storage tank 60, and the circulation cycle of the refrigerant can be formed using the refrigerant. Accordingly, the refrigerant can be continuously circulated through the circulation cycle of the refrigerant to continuously maintain the storage space 10a of the storage container 10 at the target temperature, so that the freshness of the product can be preserved for a long period of time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not to be limited to the details thereof and that various changes and modifications will be apparent to those skilled in the art. And various modifications and variations are possible within the scope of the appended claims.

1: Agricultural food delivery system
10: storage container 10a: storage space
12: cover 20: refrigerant tube
22: first line 24: second line
26: third line 30: phase change material pack
40: circulating fan 50: cooling tower
52: adiabatic partition 52a: connecting chamber
52b: machine room 52c: endothermic room
52d: heat generating chamber 60: storage tank
70: Pump 80: Dehumidification fan
90: thermoelectric element 92:
92a: heat absorbing part fin 94:
94a: Heat generating part pin 100: Suction fan
110: exhaust fan

Claims (9)

A method of controlling a temperature of a storage container using a refrigerant circulating along a refrigerant pipe,
(a) cooling the refrigerant by exchanging heat between the refrigerant and the thermoelectric element;
(b) supplying the refrigerant to a storage space of a storage container capable of receiving a storage object;
(c) a phase change material pack disposed between the refrigerant tube and the storage space, the phase change material pack being filled with a phase change material capable of storing heat of latent heat, and a coolant of the coolant is stored in the phase change material by latent heat, Exchanging heat between the phase change material pack and the inner space of the storage space to cool the inner space of the storage space;
(d) recovering the refrigerant; And
(e) exchanging heat between the phase change material pack and the inner space of the storage space until the phase change of the phase change material is completed when the heat exchange between the refrigerant and the phase change material pack is interrupted, And continuously cooling the temperature of the storage container. The method according to claim 1,
The refrigerant,
Wherein the temperature of the storage container is at least one of water and an antifreeze. 3. The method of claim 2,
The refrigerant,
50 to 90 vol.% Water, and 10 to 50 vol.% Antifreeze. The method according to claim 1,
Wherein the thermoelectric element has a heat absorbing portion capable of absorbing heat and a heat generating portion capable of absorbing and absorbing heat absorbed by the heat absorbing portion,
Wherein the step (a) is performed by the refrigerant pipe being in thermal contact with the heat absorbing part, and the heat absorbing part absorbs the heat of the refrigerant through the refrigerant pipe. 5. The method of claim 4,
There is provided a suction fan capable of sucking air from the outside and supplying the air to the heat generating unit,
Wherein the step (a) is performed while cooling the heating unit with air supplied from the outside by driving the suction fan. 6. The method of claim 5,
A discharge fan capable of sucking air having passed through the heat generating portion and discharging the air to the outside,
Wherein the step (a) is performed while discharging the air that has cooled the heating unit to the outside by driving the discharge fan. delete The method according to claim 1,
A circulation fan capable of purifying the inside of the storage space is installed at one side of the storage space,
Wherein the step (c) is performed while circulating the inner space of the storage space using a circulation fan. The method according to claim 1,
A storage tank capable of containing the refrigerant is installed,
Wherein the step (a) is performed by cooling the refrigerant discharged from the storage tank,
Wherein the step (d) is performed by recovering the refrigerant that has cooled the storage space to the storage tank.

Images