JP6641752B2 - Cooling system - Google Patents

Description

  The present invention relates to a cooling device, and more particularly to a cooling device including a fan for defrosting.

  BACKGROUND ART Conventionally, a cooling device including a fan (nozzle) for defrosting is known (for example, see Patent Document 1).

  In the cooling device described in Patent Literature 1, in order to remove frost generated on the surfaces of the plurality of fins joined to the heat transfer tube by cooling the air, the fins move in a direction parallel to or perpendicular to the plane direction of the fins, and The nozzle which injects air to the surface of is provided.

JP 2008-64326 A

  However, in the cooling device described in Patent Literature 1, the frost blown off by the air jetted from the nozzles scatters outside the cooling device and adheres to the product, thereby deteriorating the quality of the product. Can be considered.

  The present invention has been made in order to solve the above-described problems, and one object of the present invention is to suppress scattering of frost to the outside of the device, thereby preventing the frost from adhering to the product. An object of the present invention is to provide a cooling device capable of suppressing quality deterioration.

In the cooling device according to one aspect of the present invention, the cooling heat exchanger and the air cooled by the cooling heat exchanger are blown in a first direction and rotated in a direction opposite to a rotation direction when cooling the air. A defrosting unit that is disposed downstream of the cooling heat exchanger in a second direction opposite to the first direction and that stores defrosted frost. Sometimes, when the fan rotates in a direction opposite to the rotation direction when cooling the air, the air moves from the first direction side to the second direction side of the cooling heat exchanger and is externally transmitted through the frost accommodating part side. It is configured to flow to.

  In a cooling device according to one aspect of the present invention, a fan that defrosts by rotating in a direction opposite to a rotation direction when cooling air, and a cooling heat exchanger in a second direction opposite to the first direction And a frost accommodating section that is arranged downstream of the frost and accommodates defrosted frost. Accordingly, when the air is cooled, defrosting is performed by rotating the fan in a direction opposite to the rotation direction of the fan, so that the cooling is caused by the frost accommodating portion disposed on the downstream side in the second direction. Can contain frost. In addition, since the frost is stored in the frost storage unit, the frost is prevented from being scattered to the outside of the cooling device. Therefore, it is possible to suppress the deterioration of the quality of the product due to the adhesion of the frost to the product arranged in the refrigerated warehouse. it can.

  In the cooling device according to the one aspect, preferably, when defrosting, the direction of the air is reversed from that when cooling the air, and the fan is controlled such that the wind speed is higher than when the air is cooled. It is configured to: With this configuration, the wind speed at the time of defrosting is higher than the wind speed at the time of cooling air, so that the efficiency of defrosting can be improved. In addition, since the wind speed at the time of cooling is smaller than the wind speed at the time of defrosting, it is possible to suppress the scattering of frost at the time of cooling, and to prevent the frost from adhering to the products arranged in the refrigerated warehouse. Deterioration of product quality can be suppressed.

  The cooling device according to the above aspect preferably further includes a housing for housing the cooling heat exchanger and the fan, and the frost housing portion is provided inside the housing. According to this configuration, when defrosting, the frost generated inside the housing due to cooling can be stored in the frost storage unit without going out of the housing, so that the frost can be transferred to the outside of the cooling device by defrosting. Can be further suppressed, and the quality deterioration of the product due to the adhesion of the frost to the product can be further suppressed.

  Preferably, the cooling device according to the one aspect further includes an air resistor that is disposed in the flow path on the downstream side of the frost storage unit in the second direction during defrosting and that does not allow frost and allows air to pass. According to this structure, the air resistor that does not allow frost and allows air to pass through is disposed downstream of the frost storage unit in the second direction. Therefore, the second direction of frost when defrosting is performed by the air resistor. Movement to the outside of the cooling device can be more effectively suppressed, and the deterioration of the quality of the product due to the adhesion of the frost to the product can be more effectively suppressed. In addition, since the air resistor allows air to pass through, the air is blocked by the air resistor and the backflow of frost due to rebound can be suppressed.

  In this case, preferably, the air resistor is rotatable, and is rotated so as to cover the frost accommodating part when cooling the air, and the downstream flow path is used during defrosting. It is configured to be turned to close. With this configuration, when defrosting, the air resistor that is rotated so as to close the flow path on the downstream side can prevent the frost from scattering to the outside of the cooling device, and can perform cooling. In doing so, the air resistor rotates so as to cover the frost accommodating portion, so that the air resistance at the time of cooling is reduced, and an increase in power consumption due to cooling can be suppressed. In addition, when cooling, when the frost contained in the frost storage unit is melted by heating, the air resistor is rotated so as to cover the frost storage unit. It becomes difficult to dissipate heat from the housing. As a result, it is possible to suppress an increase in power consumption due to cooling and increase the efficiency of melting.

  The cooling device according to the one aspect is preferably provided in the vicinity of the frost accommodating section, and further includes a heating section for melting the frost accommodated in the frost accommodating section, wherein the heating section is supplied with an electric heater or a high-temperature refrigerant. It includes at least one of the high pressure pipes of the cooling circuit. According to this configuration, the frost contained in the frost containing section can be heated and melted by the electric heater. Also, by the heat generated by the high-pressure pipe of the cooling circuit, the frost contained in the frost storage section can be heated and melted, so that the high-pressure pipe of the cooling circuit is used instead of an electric heater or as an auxiliary, Power consumption due to the use of the electric heater can be reduced or reduced.

  According to the present invention, as described above, it is possible to provide a cooling device capable of suppressing the deterioration of the product quality due to the adhesion of the frost to the product by suppressing the scattering of the frost to the outside of the device.

It is sectional drawing which showed the structure of the cold storage in which the cooling device by 1st and 2nd embodiment of this invention was installed. It is a block diagram showing the whole cooling unit composition by a 1st embodiment of the present invention. It is sectional drawing which showed the structure around the cooling heat exchanger of the cooling device at the time of the air cooling by 1st Embodiment of this invention. It is sectional drawing which showed the structure around the cooling heat exchanger of the cooling device at the time of the defrost by 1st Embodiment of this invention. It is a block diagram showing the whole cooling unit composition by a 2nd embodiment of the present invention. It is sectional drawing which showed the structure around the cooling heat exchanger of the cooling device at the time of the air cooling by 2nd Embodiment of this invention. It is sectional drawing which showed the structure around the cooling heat exchanger of the cooling device at the time of the defrost by 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(1st Embodiment)
First, a cooling device 100 according to a first embodiment of the present invention will be described with reference to FIGS.

(Overall configuration of refrigerated warehouse)
As shown in FIG. 1, a cooling device 100 according to the first embodiment is installed to cool an internal space 2 a of a refrigerator room 2 provided in a refrigerator warehouse 1 to a predetermined temperature. The cooling device 100 is attached to the lower surface 3 a of the ceiling 3 of the refrigerator compartment 2. Further, the internal space 2a is maintained at the temperature T, and the articles 4 placed in the refrigerator compartment 2 are cooled and stored at the temperature T.

  On the lower surface 3a of the ceiling 3 of the refrigerating compartment 2, an air curtain device 6 configured to suck in the cool air from the cooling device 100 and circulate the blown cool air into the internal space 2a is installed. .

  Here, the flow of the air flow (cool air) in the refrigerator compartment 2 will be described. As shown in FIG. 1, in the internal space 2 a, the cool air cooled by the cooling device 100 and blown out from the outlet 101 of the cooling device 100 travels along the lower surface 3 a of the ceiling 3 in the direction of the arrow X <b> 1 (horizontal direction). It is sucked into the suction port 6a of the air curtain device 6. The cool air changes direction and becomes an airflow P1 from the outlet 6b of the air curtain device 6 and is blown obliquely downward (in the direction of arrow Z2 and in the direction of arrow X2). That is, the outlet 6b has an opening shape such that the blown-out cool air forms an airflow P1 directed toward the X2 side by a predetermined angle from a direction directly below. After that, after reaching the floor 5, the cool air (airflow P1) changes direction and is mostly circulated along the floor 5 along the direction of the arrow X2, and travels in the direction of the arrow Z1 along the vicinity of the side wall 7 on the X2 side. And is sucked into the suction port 102 of the cooling device 100. Thus, the cool air circulation flow G1 circulating largely clockwise is formed in the internal space 2a. Hereinafter, as shown in FIG. 1, the direction substantially perpendicular to the side wall 7 is the X direction (X1 direction and X2 direction), and the direction substantially perpendicular to the lower surface 3a is the Z direction (Z1 direction and Z2 direction). And

(Overall configuration of cooling device)
As shown in FIG. 2, the cooling device 100 includes a cooling heat exchanger 8, a compressor 9, a condenser 10, an expansion valve 11, and a control unit 12.

  As shown in FIGS. 2 to 4, the cooling heat exchanger 8 and the compressor 9 are connected by a pipe 100a. As described later, low-pressure refrigerant vapor flows through the pipe 100a, and the low-pressure refrigerant vapor is configured to be sucked into the compressor 9. Further, the compressor 9 is configured to compress the low-pressure refrigerant vapor to change it into high-temperature and high-pressure refrigerant vapor.

  The compressor 9 and the condenser 10 are connected by a pipe 100b. The high-temperature and high-pressure refrigerant vapor flowing through the pipe 100b is configured to enter the condenser 10. The condenser 10 is configured to change the high-temperature and high-pressure refrigerant vapor into a high-pressure refrigerant liquid by cooling the high-temperature and high-pressure refrigerant vapor with cooling water flowing through the condenser 10 or air blown from the fan 10a. I have.

  The condenser 10 and the expansion valve 11 are connected by a pipe 100c. The high-pressure refrigerant liquid flowing through the pipe 100 c is configured to enter the expansion valve 11. The expansion valve 11 is configured to change the high-pressure refrigerant liquid to a low-temperature low-pressure state by restricting and expanding the high-pressure refrigerant liquid that has entered the expansion valve 11. The low-temperature and low-pressure refrigerant is in the state of wet steam in which saturated steam and saturated liquid coexist near the outlet of the expansion valve 11. The pipe 100c is an example of the “high-pressure pipe of the cooling circuit” in the claims.

  As shown in FIG. 2, the expansion valve 11 and the cooling heat exchanger 8 are connected by a pipe 100d. The low-temperature and low-pressure wet steam flowing through the pipe 100d is configured to enter the cooling heat exchanger 8. The cooling heat exchanger 8 is configured such that the low-temperature and low-pressure wet steam flowing through the cooling heat exchanger 8 changes into low-pressure refrigerant vapor by removing the heat of the air blown from the fan 8a. . The air from the fan 8a whose heat has been removed by the low-temperature and low-pressure wet steam becomes cooling air and exits the cooling device 100, thereby cooling the internal space 2a (see FIG. 1).

  As shown in FIGS. 2 to 4, the cooling heat exchanger 8 and the fan 8a are provided inside the housing 8b.

  As shown in FIG. 2, the control unit 12 is connected to a fan 8a, a fan 10a, a compressor 9, an expansion valve 11, and a later-described frost catcher 13 (see FIGS. 3 and 4) inside the housing 8b. , And is configured to control each operation.

  As shown in FIGS. 3 and 4, the cooling heat exchanger 8 is joined with a plurality of fins 8c for transmitting the heat of the high-temperature fluid to the low-temperature fluid. The plurality of fins 8c are arranged in the cooling heat exchanger 8 in a direction substantially perpendicular to the Y1 direction. Hereinafter, as shown in FIGS. 3 and 4, a direction substantially perpendicular to each of the X direction and the Z direction is referred to as a Y (Y1) direction.

  Here, in the first embodiment, the cooling heat exchanger 8 and the air cooled by the cooling heat exchanger 8 are blown in the X1 direction, and the rotation direction (C1) in cooling the air is opposite to the rotation direction (C1). A fan 8a that defrosts by rotating to (C2), and a frost storage unit that is disposed downstream of the cooling heat exchanger 8 in the X2 direction opposite to the X1 direction and stores the defrosted frost 14 14a. Specifically, as shown in FIG. 3 and FIG. 4, the cooling heat exchanger 8 is arranged in the housing 8b so as to be inclined in the X2 direction. A concave frost accommodating portion 14a is provided on an extension of the wind direction A2 (see FIG. 4) passing through the cooling heat exchanger 8 when defrosting. In addition, when defrosting, the rotation direction of the fan 8a is reversed so that the frost 14 attached to the fins 8c is blown off toward the frost accommodating portion 14a. The fan 8a is arranged on the side (X1 direction side) opposite to the frost accommodating section 14a side (X2 direction side) of the cooling heat exchanger 8.

  Further, in the first embodiment, when defrosting, the air direction (wind direction A1) is reverse to the air direction (wind direction A1) when cooling the air, and the wind speed is made larger than when cooling the air. The fan 8a is configured to be controlled. Specifically, the rotation direction (C1) of the fan 8a at the time of defrosting (see FIG. 4) is reversed (C2) with respect to the rotation direction (C1) of the fan 8a at the time of cooling air (see FIG. 3). Thus, the wind direction is controlled to be opposite. Further, when defrosting, control is performed so as to increase the rotation speed of the fan 8a and increase the wind speed as compared with when cooling the air.

  In the first embodiment, the frost catcher 13 that is disposed in the flow path 8d on the downstream side of the frost accommodating portion 14a in the X2 direction during defrosting and that does not allow the frost 14 to pass therethrough and further allows the air to pass therethrough is further provided. Specifically, as shown in FIG. 4, the frost catcher 13 is disposed so as to be substantially perpendicular to the flow channel 8d during defrosting, and the flow channel 8d is covered with the frost catcher 13. Is configured. The frost catcher 13 has a mesh shape and is made of metal. In addition, the frost catcher 13 is an example of the “air resistor” in the claims.

  Further, in the first embodiment, the frost catcher 13 is configured to be rotatable and to be rotated so as to cover the frost accommodating portion 14a when cooling the air. Specifically, as shown in FIG. 3, when cooling the air, the frost catcher 13 is arranged at a position where the frost catcher 13 turns to separate the frost accommodating portion 14 a from the flow path 8 d.

  In the first embodiment, the electric heater 15 is provided near the frost accommodating portion 14a and melts the frost 14 accommodated in the frost accommodating portion 14a. Specifically, as shown in FIGS. 3 and 4, the two electric heaters 15 are respectively arranged in contact with the bottom surface 14b of the frost container 14a.

  A water distribution pipe 16 is connected to the frost accommodating portion 14a. The frost 14 melted by the heat of the electric heater 15 and liquefied is drained through the water distribution pipe 16.

  In the first embodiment, the following effects can be obtained.

  In the first embodiment, as described above, the cooling heat exchanger 8 and the air cooled by the cooling heat exchanger 8 are blown in the X1 direction, and the rotation direction (C1) when cooling the air. A fan 8a that defrosts by rotating in the opposite direction (C2), and a frost that is arranged downstream of the cooling heat exchanger 8 in the X2 direction opposite to the X1 direction and contains the defrosted frost 14. It is configured so as to include the accommodation portion 14a. Thereby, the fan 8a that defrosts by rotating in the direction (C2) opposite to the rotation direction (C1) when cooling the air, and the downstream of the cooling heat exchanger 8 in the X2 direction opposite to the X1 direction. And a frost accommodating portion 14a arranged on the side and accommodating the defrosted frost 14. Accordingly, when the air is cooled, the defrosting is performed by rotating the fan 8a in the direction (C2) opposite to the rotation direction (C1) of the fan 8a, so that the frost storage disposed on the downstream side in the X2 direction. The part 14a can contain the frost 14 generated by cooling. Further, since the frost 14 is stored in the frost storage unit 14a to prevent the frost 14 from scattering to the outside of the cooling device 100, the product 4 due to the adhesion of the frost 14 to the product 4 disposed in the refrigerated warehouse 1 is stored. Quality degradation can be suppressed.

  In the first embodiment, as described above, when defrosting, the direction of air cooling (wind direction A1) is opposite to the direction of wind (wind direction A2), and the wind speed is lower than when cooling air. Is configured so that the fan 8a is controlled so as to increase. Thereby, the wind speed at the time of defrosting is higher than the wind speed at the time of cooling air, so that the efficiency of defrosting can be improved. Further, since the wind speed at the time of cooling is smaller than the wind speed at the time of defrosting, it is possible to suppress the scattering of the frost 14 at the time of cooling, and it is also possible to suppress the frost on the products 4 arranged in the refrigerated warehouse 1. Deterioration of the quality of the product 4 due to the adhesion of 14 can be suppressed.

  Moreover, in 1st Embodiment, as mentioned above, the housing 8b which accommodates the heat exchanger 8 for cooling and the fan 8a is further provided, and the frost accommodating part 14a is comprised so that it may be provided inside the housing 8b. Thus, when defrosting, the frost 14 generated inside the housing 8b due to cooling can be stored in the frost storage portion 14a without being exposed to the outside of the housing 8b. The scattering of the frost 14 on the product 4 can be further suppressed, and the quality deterioration of the product 4 due to the attachment of the frost 14 to the product 4 can be further suppressed.

  Further, in the first embodiment, as described above, the frost catcher 13 which is disposed in the flow path 8d on the downstream side of the frost accommodating portion 14a in the X2 direction in the defrosting and does not allow the frost 14 to pass and also allows the air to pass therethrough is further provided. Configure to provide. As a result, the frost catcher 13 that does not allow the frost 14 to pass therethrough and allows the air to pass through is disposed downstream of the frost accommodating portion 14a in the X2 direction, so that the frost catcher 13 moves the frost 14 in the X2 direction when defrosting. Is prevented, and scattering of the frost 14 to the outside of the cooling device 100 can be more effectively suppressed, and quality deterioration of the product 4 due to adhesion of the frost 14 to the product 4 can be more effectively suppressed. it can. Further, since the frost catcher 13 allows air to pass through, the air is blocked by the frost catcher 13 and the backflow of the frost 14 due to rebound can be suppressed.

  Further, in the first embodiment, as described above, the frost catcher 13 is rotatable, and is rotated so as to cover the frost accommodating portion 14a when cooling the air. Is configured to be rotated so as to close the downstream flow path 8d. Thereby, at the time of defrosting, the frost catcher 13 rotated so as to close the downstream flow path 8d can prevent the frost 14 from scattering to the outside of the cooling device 100 and cool. In this case, since the frost catcher 13 rotates so as to cover the frost accommodating portion 14a, the air resistance at the time of cooling is reduced, and an increase in power consumption due to cooling can be suppressed. In addition, when cooling, when the frost 14 contained in the frost containing portion 14a is melted by heating, the frost catcher 13 is rotated so as to cover the frost containing portion 14a. This makes it difficult for heat due to heating to be dissipated from the frost accommodating portion 14a, so that an increase in power consumption due to cooling and an increase in melting efficiency can be achieved.

(2nd Embodiment)
Next, a second embodiment will be described with reference to FIGS. In the second embodiment, unlike the first embodiment in which the electric heater 15 heats and melts the frost 14, the pipe 200c heats and melts the frost 14. The pipe 200c is an example of the “high pressure pipe of the cooling circuit” in the claims. In the drawings, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment.

(Overall configuration of cooling device)
As shown in FIG. 5, the cooling device 200 includes a cooling heat exchanger 8, a compressor 9, a condenser 10, an expansion valve 11, and a control unit 212.

  As shown in FIG. 5, the condenser 10 and the expansion valve 11 are connected by a pipe 200c. The high-pressure refrigerant liquid flowing through the pipe 200c is configured to enter the expansion valve 11. The expansion valve 11 is configured to change the high-pressure refrigerant liquid to a low-temperature low-pressure state by restricting and expanding the high-pressure refrigerant liquid that has entered the expansion valve 11. The low-temperature and low-pressure refrigerant is in the state of wet steam in which saturated steam and saturated liquid coexist near the outlet of the expansion valve 11. The pipe 200c is an example of the “high pressure pipe of the cooling circuit” in the claims.

  As shown in FIGS. 5 to 7, the cooling heat exchanger 8 and the fan 8a are provided inside the housing 208b.

  As shown in FIG. 5, the control unit 212 is connected to the fan 8a, the fan 10a, the compressor 9, the expansion valve 11, and the frost catcher 13 (see FIGS. 6 and 7) inside the housing 208b, respectively. Is configured to control the operation.

  Also, as shown in FIG. 5, the pipe 200c is configured to pass through the inside of the housing 208b.

  Here, in the second embodiment, as shown in FIG. 6, the pipe 200c is provided near the frost accommodating portion 14a, and is configured to melt the frost 14 accommodated in the frost accommodating portion 14a. Specifically, the pipe 200c is configured to pass through the inside of the frost container 14a.

  The other configuration of the second embodiment is the same as that of the first embodiment.

  In the second embodiment, the following effects can be obtained.

  In 2nd Embodiment, as mentioned above, it is provided near the frost accommodating part 14a, and it is comprised so that the piping 200c which melts the frost 14 accommodated in the frost accommodating part 14a may be further provided. Accordingly, the heat generated by the pipe 200c can heat and melt the frost 14 stored in the frost storage unit 14a. Therefore, by using the pipe 200c instead of the electric heater 15, the electric heater 15 can be used. Power consumption can be reduced.

  The other effects of the second embodiment are the same as those of the first embodiment.

[Modification]
It should be noted that the embodiments disclosed this time are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description of the embodiments, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

  For example, in the first and second embodiments, an example has been described in which the cooling heat exchanger is disposed obliquely with respect to the flow path, but the present invention is not limited to this. The cooling heat exchanger may be arranged without being inclined in the oblique direction with respect to the flow path.

  Further, in the first and second embodiments, in the first and second embodiments, an example in which a plurality of fins are arranged so as to be arranged substantially perpendicular to the Y1 direction has been described. Not limited. A plurality of fins may be arranged so as to be arranged substantially horizontally in the Y1 direction.

  Further, in the first and second embodiments, the example in which the heating by the electric heater or the heating by the high-pressure pipe of the cooling circuit is performed is described, but the present invention is not limited to this. The heating may be performed by both the heater and the high-pressure pipe of the cooling circuit.

  Further, in the first and second embodiments, the example in which the shape of the frost catcher is a mesh is shown, but the present invention is not limited to this. Shapes other than the mesh shape may be used.

  Further, in the first and second embodiments, the example in which the material of the frost catcher is metal has been described, but the present invention is not limited to this. Materials other than metal may be used.

  In the first and second embodiments, an example has been shown in which the frost catcher is substantially perpendicular to the flow path when defrosting, but the present invention is not limited to this. Even if the flow path does not become substantially vertical, it is sufficient that the flow path is closed by the frost catcher.

  Further, in the second embodiment, an example is described in which the high-pressure pipe of the cooling circuit is configured to pass through the inside of the frost accommodating section, but the present invention is not limited to this. The cooling circuit may be arranged in a place other than the inside of the frost storage unit as long as it is near the frost storage unit.

Reference Signs List 8 heat exchanger for cooling 8a fan 8b, 208b housing 8d flow path 13 frost catcher (air resistor)
14 Frost 14a Frost storage unit 15 Electric heater 100, 200 Cooling device 100c, 200c Piping (high-pressure piping of cooling circuit)
A1 Wind direction for cooling air A2 Wind direction for defrosting C1 Rotation direction of fan 8a for cooling air C2 Rotation direction of fan 8a for defrosting

Claims (6)

A heat exchanger for cooling;
A fan that blows air cooled by the cooling heat exchanger in a first direction, and defrosts by rotating in a direction opposite to a rotation direction when cooling the air,
A frost accommodating portion that is arranged downstream of the cooling heat exchanger in a second direction opposite to the first direction and accommodates defrosted frost,
At the time of defrosting, the air rotates from the first direction side of the cooling heat exchanger to the second direction side by rotating in a direction opposite to a rotation direction when the fan cools the air. A cooling device configured to flow to the outside via the frost storage unit side.   In the case of defrosting, the direction of the air is reversed when cooling the air, and the fan is configured to be controlled so that the wind speed is higher than when the air is cooled. Item 2. The cooling device according to Item 1. Further comprising a housing for housing the cooling heat exchanger and the fan,
The cooling device according to claim 1, wherein the frost storage unit is provided inside the housing.   4. The air resistor according to claim 1, further comprising an air resistor that is disposed in the flow path on the downstream side of the frost storage unit in the second direction during defrosting and that does not allow the frost to pass and allows the air to pass. The cooling device according to the item.   The air resistor is rotatable, and is rotated so as to cover the frost accommodating portion when cooling the air, and closes the downstream flow path when defrosting. The cooling device according to claim 4, wherein the cooling device is configured to be rotated. A heating unit provided near the frost storage unit and configured to melt the frost stored in the frost storage unit;
The cooling device according to any one of claims 1 to 5, wherein the heating unit includes at least one of an electric heater and a high-pressure pipe of a cooling circuit through which a high-temperature refrigerant flows.

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