WO2023054441A1

WO2023054441A1 - Cooling system

Info

Publication number: WO2023054441A1
Application number: PCT/JP2022/036098
Authority: WO
Inventors: 蹊男高山; 歩森宗
Original assignee: 伸和コントロールズ株式会社
Priority date: 2021-09-29
Filing date: 2022-09-28
Publication date: 2023-04-06
Also published as: JPWO2023054441A1; TW202323741A

Abstract

The cooling system S1 according to one embodiment of the present invention comprises: a refrigeration cycle device 10 that circulates a natural refrigerant; a first cooling liquid circulation device 20 that circulates first cooling liquid cooled by the natural refrigerant; and a second cooling liquid flow device 30 that allows passage of second cooling liquid cooled by the first cooling liquid circulated by the first cooling liquid circulation device 20.

Description

cooling system

Embodiments of the present invention relate to a cooling system that cools a coolant with a refrigerant circulated by a refrigeration cycle device.

　Recently, refrigeration cycle equipment that uses natural refrigerants has attracted attention. Natural refrigerants have extremely low ozone layer depletion potential and global warming potential compared to common Freon-based refrigerants. Therefore, natural refrigerants are extremely useful from the viewpoint of environmental protection.

Examples of natural refrigerants include ammonia, carbon dioxide, air, oxygen, and nitrogen. Of these, carbon dioxide, air, oxygen, and nitrogen have extremely low boiling points, so they can be cooled in an ultra-low temperature zone.

As a refrigeration cycle device using natural refrigerant, an air refrigeration cycle device using air has been conventionally known (for example, WO2018/070893A1). Such an air refrigeration cycle device has already been used in a large freezer or the like.

In addition, the air refrigeration cycle device has recently attracted attention for its application to the storage of new coronavirus vaccines, which require ultra-low temperature storage.

A cooling system called an indirect expansion type generally cools the coolant circulated by the coolant circulation device with the refrigerant circulated by the refrigeration cycle device, and the cooled coolant cools the temperature controlled object. For example, the air refrigeration cycle device described above may be used in an indirect expansion refrigeration system.

However, as described above, air as a refrigerant has an extremely low boiling point, so depending on the setting of the cooling temperature during expansion, such as -70°C or lower, the type of cooling liquid circulated by the cooling liquid circulation device may be limited. There is

In some cases, the limitations described above may force the selection of an undesirable type of cooling liquid for the product or manufacturing facility whose temperature is to be controlled. The situation in which the degree of freedom in selecting the cooling liquid is limited in this way is one of the reasons why adoption of a cooling system using an air refrigeration cycle device is postponed.
For example, a cooling fluid that can be used in an ultra-low temperature range around -100°C includes silicone oil. However, siloxane in silicone oil may cause disconnection of electronic components. Therefore, for example, in semiconductor manufacturing facilities, the use of cooling equipment using silicone oil may be avoided.

In addition, natural refrigerants have concerns such as toxicity, flammability, and high pressure. Due to such concerns, adoption of a refrigeration cycle device using a natural refrigerant and a cooling system using the refrigeration cycle device may be postponed.

In addition, the cooling temperature of extremely low-temperature refrigerants may be over-specified for temperature control targets. In this case, the temperature may be adjusted to a desired temperature range by heating the cooled coolant with a heater. However, such an adjustment is not desirable from the viewpoint of suppressing energy consumption.

In view of the above circumstances, an object of the present invention is to provide a cooling system that can effectively cool a temperature-controlled target with a cooling liquid cooled by a natural refrigerant circulated by a refrigeration cycle device.

A cooling system according to an embodiment of the present invention includes a refrigeration cycle device that circulates a natural refrigerant, a first coolant circulation device that circulates a first coolant that is cooled by the natural coolant, and the first coolant. a second cooling liquid flow device for causing a flow of a second cooling liquid cooled by the first cooling liquid circulated by the circulation device.

In this cooling system, by intentionally providing the first coolant circulation device between the refrigeration cycle device and the second coolant circulation device, the cooling efficiency of the second coolant by the natural refrigerant is directly improved by the natural refrigerant. Intentionally dropping the second cooling liquid compared to the case of cooling. As a result, it is possible to alleviate the restriction on the degree of freedom in selecting the type of the second cooling liquid that occurs when the second cooling liquid is cooled directly by the natural refrigerant. Therefore, while selecting the first coolant from the viewpoint that it is desirable when directly cooled by the natural refrigerant, for example, the temperature control target is cooled with the second coolant selected from the viewpoint that it is desirable for the temperature control target. becomes possible.
In addition, by intentionally lowering the cooling efficiency of the second cooling liquid by the natural refrigerant compared to the case where the second cooling liquid is cooled directly by the natural refrigerant, the temperature of the second cooling liquid can be adjusted without using a heater. The zone can be adjusted to the desired temperature zone. As a result, it becomes possible to cool the object to be temperature-controlled in a desired temperature range while suppressing energy consumption.
Also, the physical distance between the refrigeration cycle device and the second cooling liquid circulation device can be increased. In addition, exposure of the natural refrigerant to the second coolant can be avoided, and inflow of the natural refrigerant into the temperature controlled side can be avoided. As a result, even if the natural refrigerant has concerns such as toxicity, combustibility, and high pressure, it is possible to cool the object of temperature control while suppressing the effects of the concerns.
Therefore, the cooling liquid cooled by the natural refrigerant circulated by the refrigeration cycle device can effectively cool the object to be temperature controlled.

The type of the first cooling liquid and the type of the second cooling liquid may be different.
In this case, for example, a cooling liquid that is desirable for cooling by a natural refrigerant, for example, that does not interfere with the operation or the like is selected as the first cooling liquid, and a cooling liquid that is desirable for the temperature control object, unlike the first cooling liquid, is selected as the first cooling liquid. By selecting the two cooling liquids, it is possible to effectively cool the object of temperature control.

The refrigeration cycle device and the first coolant circulation device are connected by a first heat exchanger, the first coolant is cooled by the natural refrigerant in the first heat exchanger, and the first coolant circulation device and the second coolant circulation device are connected by a second heat exchanger, the second coolant is cooled by the first coolant in the second heat exchanger, and the first coolant circulation device is a first flow path connecting an outlet of the first heat exchanger that discharges the first cooling liquid and an inlet of the second heat exchanger that receives the first cooling liquid; and a second flow path connecting the discharge port of the second heat exchanger for discharging liquid and the receiving port of the first heat exchanger for receiving the first cooling liquid; and for circulating the first cooling liquid. and a pump that generates a driving force of
In this case, the very simple first cooling liquid circulating device can effectively cool the temperature controlled object while suppressing the manufacturing cost.

The first flow path and the second flow path are connected by an internal heat exchanger, and in the internal heat exchanger, the heat is discharged from the discharge port of the first heat exchanger to the reception port of the second heat exchanger. The first cooling liquid before being received may be heat-exchanged with the first cooling liquid discharged from the discharge port of the second heat exchanger and before being received by the receiving port of the first heat exchanger. .
In this case, by suppressing the temperature difference between the natural refrigerant and the first coolant in the first heat exchanger, the load on the first heat exchanger can be reduced, and highly reliable operation can be performed.

The first cooling liquid circulation device may further include a bypass flow path connecting the first flow path and the second flow path and allowing the first cooling liquid to flow.
In this case, by suppressing the temperature difference between the first cooling liquid and the second cooling liquid in the second heat exchanger, the load on the second heat exchanger can be reduced, and highly reliable operation can be performed. In addition, the cooling efficiency of the second cooling liquid by the natural refrigerant can be lowered more easily than when the second cooling liquid is directly cooled by the natural refrigerant. This can improve the degree of freedom in selecting the type of the second cooling liquid.

The first cooling liquid circulation device includes a branch flow path branched from the second flow path and connected to the second flow path at a position upstream of the branched position, and a second flow path provided on the branch flow path. 3 heat exchangers.
In this case, the third heat exchanger can perform cooling in a temperature zone higher than that of the second heat exchanger. This can expand the application pattern and application range of the cooling system.

A third coolant flow device is connected to the third heat exchanger, and the third coolant is cooled by the first coolant in the third heat exchanger. good too.
The cooling temperature of natural refrigerants with extremely low boiling points, such as air, carbon dioxide, and oxygen, may be over-specified for temperature control targets. In such a case, in this configuration, by distributing the refrigerating capacity between the second heat exchanger and the third heat exchanger, it is possible to effectively utilize the refrigerating capacity while avoiding excessive cooling.

The second coolant flow device is connected to the third heat exchanger, and the second coolant is cooled by the third heat exchanger and then cooled by the second heat exchanger. good.
In this case, the temperature difference between the first cooling liquid and the second cooling liquid in the second heat exchanger can be suppressed by cooling the second cooling liquid in stages in the third heat exchanger and the second heat exchanger. Therefore, the load on the second heat exchanger can be reduced, and highly reliable operation can be performed.

The first cooling liquid may be silicone oil, and the second cooling liquid may be an ether-based liquid.

The refrigeration cycle device may be an air refrigeration cycle device.

According to the present invention, the temperature control target can be effectively cooled by the cooling liquid cooled by the natural refrigerant circulated by the refrigeration cycle device.

1 is a diagram schematically showing a cooling system according to a first embodiment; FIG. FIG. 5 is a diagram schematically showing a cooling system according to a second embodiment; FIG. FIG. 5 is a diagram schematically showing a cooling system according to a third embodiment; FIG. FIG. 12 is a diagram schematically showing a cooling system according to a fourth embodiment; FIG. FIG. 11 is a diagram schematically showing a cooling system according to a fifth embodiment; FIG. FIG. 11 is a diagram schematically showing a cooling system according to another embodiment; FIG. 11 is a diagram schematically showing a cooling system according to another embodiment;

Each embodiment will be described in detail below with reference to the accompanying drawings.

<First embodiment>
FIG. 1 is a diagram schematically showing a cooling system S1 according to the first embodiment. A cooling system S1 shown in FIG. a flow device 30;

The refrigeration cycle device 10 and the first coolant circulation device 20 are connected by a first heat exchanger 40 . The first coolant circulation device 20 and the second coolant circulation device 30 are connected by a second heat exchanger 50 .

The natural refrigerant circulated by the refrigeration cycle device 10 cools the first coolant circulated by the first coolant circulation device 20 in the first heat exchanger 40 . The first coolant circulated by the first coolant circulation device 20 cools the second coolant circulated by the second coolant circulation device 30 in the second heat exchanger 50 .

After being cooled by the first cooling liquid in the second heat exchanger 50, the second cooling liquid is sent to a temperature control target (not shown). Then, the second cooling liquid returns to the second heat exchanger 50 after cooling the temperature controlled object.

The object of temperature control may be, for example, a wafer. In this case, the second cooling liquid may pass through the stage on which the wafer is placed and cool the wafer via the stage. The second coolant may then return to the second heat exchanger 50 after passing through the stages. However, the object of temperature control is not particularly limited, and may be, for example, the space inside the chamber.

The refrigeration cycle device 10 circulates air as a natural refrigerant in this embodiment. That is, the refrigeration cycle device 10 is an air refrigerant cycle device.

The refrigeration cycle device 10 connects the compressor 11, the cooler 12, the heat recovery exchanger 13, and the expander 14 with a refrigerant circulation path 15 so that air circulates in this order. After being compressed by the compressor 11 , the air is stepwise cooled by the cooler 12 and the heat recovery exchanger 13 and then flows into the expander 14 . The air is then expanded by expander 14 and flows out of expander 14 . The refrigerating cycle device 10 is capable of lowering the temperature of the air expanded by the expander 14 to −70° C. or lower, more specifically −70° C. to −110° C., and allowing the air to flow into the first heat exchanger 40 . However, the refrigeration cycle device 10 can also lower the temperature of the air to a range of -10°C or higher and -70°C or lower.

The above-described first heat exchanger 40 is connected to a portion of the refrigerant circuit 15 downstream of the expander 14 , and the air that has been expanded by the expander 14 and cooled to a low temperature flows into the first heat exchanger 40 . . After the air cools the first coolant in the first heat exchanger 40 , the air exits the first heat exchanger 40 toward the compressor 11 .

The air that has flowed out of the first heat exchanger 40 exchanges heat with the air that has flowed out of the cooler 12 in the recovery heat exchanger 13 before returning to the compressor 11 . Thereby, the air before flowing into the expander 14 is cooled in stages by the cooler 12 and the heat recovery exchanger 13 . Cooler 12 may cool the high pressure air exiting compressor 11, for example, by means of cooling water. The cooler 12 may be a liquid-cooled cooler or an air-cooled cooler, and is not particularly limited.

The compressor 11 and the expander 14 are connected to a drive shaft 16A of a common motor 16. As a result, the compressor 11 and the expander 14 are interlocked and rotated by the rotation of the drive shaft 16A.

Also, a portion of the refrigerant circuit 15 downstream of the compressor 11 and upstream of the cooler 12 and a portion of the refrigerant circuit 15 downstream of the expander 14 and connected to the recovery heat exchanger 13 It is connected to the upstream portion of the position by a hot bypass passage 17 that allows air to flow, and the hot bypass passage 17 is provided with a control valve 18 that controls the flow of air. Accordingly, by opening the adjustment valve 18 , high-temperature air can be mixed with the air flowing out of the first heat exchanger 40 through the hot bypass passage 17 . By such operation, freezing of the air on the downstream side of the first heat exchanger 40 can be suppressed.

Although the refrigeration cycle device 10 is an air refrigerant cycle device in this embodiment, it may be another type of device. The refrigeration cycle device 10 may be a refrigeration cycle device using carbon dioxide, oxygen, nitrogen, butane, propane, isobutane, propylene, or the like as a natural refrigerant.

The first cooling liquid circulation device 20 has a first flow path 21 , a second flow path 22 and a first cooling liquid pump 23 . The first flow path 21 connects the discharge port of the first heat exchanger 40 that discharges the first cooling liquid and the receiving port of the second heat exchanger 50 that receives the first cooling liquid. The second flow path 22 connects the discharge port of the second heat exchanger 50 that discharges the first cooling liquid and the receiving port of the first heat exchanger 40 that receives the first cooling liquid.

The first cooling liquid pump 23 generates driving force for circulating the first cooling liquid. The first cooling liquid pump 23 is provided on the second flow path 22, but its arrangement position is not particularly limited. After being discharged from the first coolant pump 23, the first coolant flows into the first heat exchanger 40 and is cooled by low-temperature air. After that, the first coolant that has flowed out of the first heat exchanger 40 flows into the second heat exchanger 50 to cool the second coolant. The second coolant that has flowed out of the second heat exchanger 50 circulates through the first coolant pump 23 to the first heat exchanger 40 .

In the present embodiment, the air expanded by the expander 14 as described above can flow into the first heat exchanger 40 after being cooled to -70°C or lower, more specifically -70°C to -110°C. Therefore, the first cooling liquid is not particularly limited as long as it is a heat medium that does not cause problems even when cooled in a temperature range of -70°C to -110°C. In this embodiment, silicone oil is used as an example. Silicone oil can be used in a temperature range as low as -120°C by mixing it with a hydrocarbon additive.

The second coolant circulation device 30 has a supply side channel 31 , a return side channel 32 and a second coolant pump 33 . The supply-side channel 31 is connected to a discharge port of the second heat exchanger 50 that discharges the second cooling liquid, and sends the second cooling liquid to the temperature control side. The return-side flow path 32 is connected to a receiving port of the second heat exchanger 50 that receives the second cooling liquid, and sends the second cooling liquid that has cooled the temperature controlled object to the second heat exchanger 50 .

The second cooling liquid pump 33 generates driving force for causing the second cooling liquid to flow. The second coolant pump 33 is provided on the return-side flow path 32, but its arrangement position is not particularly limited. After being discharged from the second coolant pump 33, the second coolant flows into the second heat exchanger 50 and is cooled by the first coolant. After that, the second coolant that has flowed out of the second heat exchanger 50 cools the temperature controlled object, and then flows into the second heat exchanger 50 via the second coolant pump 33 .

　In the present embodiment, the type of the second cooling liquid is different from the type of the first cooling liquid. Specifically, an ether-based liquid is used as the second cooling liquid. For example, the freezing point of the first coolant is lower than the freezing point of the second coolant. For example, the kinematic viscosity of the first coolant is lower than the kinematic viscosity of the second coolant. For example, at −70° C. or below, the kinematic viscosity of the first cooling liquid is lower than that of the second cooling liquid.

As described above, the first coolant can be cooled in the temperature range of -70°C to -110°C. In this case, the second cooling liquid is also cooled by the first cooling liquid in a temperature range ranging from -70°C to -110°C or a temperature range close thereto. However, the second coolant is not directly cooled by low temperature air of -70°C to -110°C. Therefore, the second cooling liquid can be tolerated with less low temperature characteristics than required for the first cooling fluid, which is directly cooled by cold air. As a result, in the present embodiment, it is possible to select a heat medium other than silicone oil, which has excellent low-temperature characteristics, as a candidate for the second coolant, and an ether-based liquid is selected as the second coolant. there is The second coolant may be a fluorine-based liquid, a fluorine-ether-based liquid, an ethylene glycol aqueous solution, or the like.

The second coolant may be a liquid containing hydrofluoroether or a liquid containing perfluoropolyether. However, the second coolant is not particularly limited. For example, the second coolant may be silicone oil. However, the use of silicone oils may be avoided due to possible siloxane problems. Ether-based or fluorine-based liquids, on the other hand, are generally chemically inert and do not have the problems of forming siloxanes. By using an ether-based or fluorine-based liquid as the second cooling liquid, it is possible to expand the application range of the cooling system S1 capable of ultra-low temperature cooling.

The cooling system S1 according to the present embodiment described above includes the refrigeration cycle device 10 that circulates the natural refrigerant, the first coolant circulation device 20 that circulates the first coolant cooled by the natural coolant, the first and a second cooling liquid flow device 30 for passing a second cooling liquid cooled by the first cooling liquid circulated by the cooling liquid circulation device 20 .

In this cooling system S1, the first cooling liquid circulation device 20 is intentionally provided between the refrigerating cycle device 10 and the second cooling liquid circulation device 30, so that the cooling efficiency of the second cooling liquid by the natural refrigerant can be directly In comparison with the case where the second coolant is cooled by the natural refrigerant, it is intentionally dropped. As a result, it is possible to alleviate the restriction on the degree of freedom in selecting the type of the second cooling liquid that occurs when the second cooling liquid is cooled directly by the natural refrigerant. Therefore, while selecting the type of the first coolant from the viewpoint of being desirable when directly cooled by the natural refrigerant, for example, the second coolant selected from the viewpoint of being desirable for the temperature control target can be used to control the temperature. Cooling becomes possible. In the present embodiment, silicone oil is specifically selected as the first cooling liquid, but an ether-based liquid, which is generally desirable for the temperature control object, may be inferior to silicone oil in low-temperature characteristics. , is selected as the second coolant.

In addition, by intentionally lowering the cooling efficiency of the second cooling liquid by the natural refrigerant compared to the case where the second cooling liquid is cooled directly by the natural refrigerant, the temperature of the second cooling liquid can be adjusted without using a heater. The zone can be adjusted to the desired temperature zone. As a result, it becomes possible to cool the object to be temperature-controlled in a desired temperature range while suppressing energy consumption. That is, many natural refrigerants have very low boiling points, and the refrigerating capacity output by the natural refrigerant may be overspecified for the temperature control target. The reduced efficiency allows the temperature of the second coolant to match the temperature range required by the temperature controlled object without using a heater.

Also, the physical distance between the refrigeration cycle device 10 and the second cooling liquid circulation device 30 can be increased. In addition, exposure of the natural refrigerant to the second coolant can be avoided, and inflow of the natural refrigerant into the temperature controlled side can be avoided. As a result, even if the natural refrigerant has concerns such as toxicity, combustibility, and high pressure, it is possible to cool the object of temperature control while suppressing the effects of the concerns.

Therefore, according to the cooling system S1 according to the present embodiment, the cooling liquid cooled by the natural refrigerant circulated by the refrigeration cycle device 10 can effectively cool the temperature controlled object.

Also, the first coolant circulation device 20 in the present embodiment has a first flow path 21, a second flow path 22, and a first coolant pump 23. , the second flow path 22 and the first coolant pump 23 only. As a result, the very simple first coolant circulation device 20 can effectively cool the object to be temperature-controlled while suppressing the manufacturing cost.

<Second Embodiment>
Next, a second embodiment will be described. Components of the present embodiment that are the same as those of the first embodiment are denoted by the same reference numerals, and overlapping descriptions are omitted. FIG. 2 is a diagram schematically showing a cooling system S2 according to a second embodiment. In the cooling system S2 shown in FIG. 2, the structure of the first coolant circulation device 20 is different from that of the first embodiment.

Specifically, the first flow path 21 and the second flow path 22 are connected by the internal heat exchanger 24 . Then, in the internal heat exchanger 24, the first cooling liquid discharged from the discharge port of the first heat exchanger 40 and before being received by the receiving port of the second heat exchanger 50 and the discharge port of the second heat exchanger 50 heat exchange with the first coolant discharged from the first heat exchanger 40 before being received in the receiving port of the first heat exchanger 40 .

In the second embodiment described above, by suppressing the temperature difference between the natural refrigerant and the first cooling liquid in the first heat exchanger 40, the load on the first heat exchanger 40 can be reduced and reliability can be improved. high operating speed.

<Third Embodiment>
Next, a third embodiment will be described. Components in this embodiment that are the same as those in the first and second embodiments are denoted by the same reference numerals, and overlapping descriptions are omitted. FIG. 3 is a diagram schematically showing a cooling system S3 according to a third embodiment. In the cooling system S3 shown in FIG. 3, the structure of the first coolant circulation device 20 is different from that of the first and second embodiments.

Specifically, the first coolant circulation device 20 further has a bypass channel 25 that connects the first channel 21 and the second channel 22 and allows the first coolant to flow. In such a configuration, the first cooling liquid returning from the second heat exchanger 50 to the first heat exchanger 40 branches to the first heat exchanger 40 side and the bypass flow path 25 . Then, the first coolant cooled by the first heat exchanger 40 and the first coolant bypassing the first heat exchanger 40 join on the downstream side of the first heat exchanger 40 . As a result, the temperature of the first coolant flowing into the second heat exchanger 50 rises.

In the third embodiment described above, by suppressing the temperature difference between the first cooling liquid and the second cooling liquid in the second heat exchanger 50, the load on the second heat exchanger 50 can be reduced and reliability can be improved. It is possible to perform high-performance driving. In addition, the cooling efficiency of the second cooling liquid by the natural refrigerant can be lowered more easily than when the second cooling liquid is directly cooled by the natural refrigerant. This can improve the degree of freedom in selecting the type of the second cooling liquid.

<Fourth Embodiment>
Next, a fourth embodiment will be described. Components in this embodiment that are the same as those in the first to third embodiments are denoted by the same reference numerals, and overlapping descriptions are omitted. FIG. 4 is a diagram schematically showing a cooling system S4 according to a fourth embodiment. In the cooling system S4 shown in FIG. 4, the structure of the first coolant circulation device 20 is different from that of the first to third embodiments.

Specifically, the first coolant circulation device 20 includes a branch flow path 26 branched from the second flow path 22 and connected to the second flow path 22 at a position P2 upstream of the branched position P1; and a third heat exchanger 60 provided on the channel 26 .

The third heat exchanger 60 is connected to a third cooling liquid circulation device 70 that allows the third cooling liquid to flow. Then, in the third heat exchanger 60, the third cooling liquid is cooled by the first cooling liquid. Since the third coolant is cooled by the first coolant that does not pass through the first heat exchanger 40, the restrictions on low-temperature characteristics are further relaxed than with the second coolant. Therefore, as the third cooling liquid, a heat medium of a different type from that of the second cooling liquid may be selected. For example, the third coolant may be an ethylene glycol aqueous solution. However, the third coolant may be silicone oil, an ether-based liquid, or a fluorine-based liquid.

In the fourth embodiment described above, it is possible for the third heat exchanger 60 to perform cooling in a temperature range higher than that of the second heat exchanger 50 . This can expand the application pattern and application range of the cooling system.

In addition, the cooling temperature of natural refrigerants with extremely low boiling points such as air, carbon dioxide, and oxygen may be over-specified for temperature control targets. In such a case, in this configuration, by distributing the refrigerating capacity between the second heat exchanger 50 and the third heat exchanger 60, it is possible to effectively utilize the refrigerating capacity while avoiding excessive cooling.

<Fifth Embodiment>
Next, a fifth embodiment will be described. Components in this embodiment that are the same as those in the first to fourth embodiments are denoted by the same reference numerals, and overlapping descriptions are omitted. FIG. 5 is a diagram schematically showing a cooling system S5 according to a fifth embodiment. In the cooling system S5 shown in FIG. 5, the structure of the first coolant circulation device 20 is different from that of the first to fourth embodiments.

Specifically, in this embodiment, the second coolant flow device 30 is connected to the second heat exchanger 50 and the third heat exchanger 60 . After being cooled by the first cooling liquid in the third heat exchanger 60 , the second cooling liquid is further cooled by the first cooling liquid in the second heat exchanger 50 . As in the fourth embodiment, the third heat exchanger 60 branches from the second flow path 22 and connects to the second flow path 22 at a position P2 upstream of the branched position P1. It is provided on the branch channel 26 .

The first coolant circulation device 20 has a tank 27 in the middle of the second flow path 22 that can store a certain amount of the first coolant, and the first coolant pump 23 sucks the first coolant in the tank 27. to dispense. A downstream end of the branch channel 26 is fluidly connected to the tank 27 .

Also, the first flow path 21 is provided with a first distribution control valve 21A. The branch flow path 26 is provided with a second distribution control valve 26A. By adjusting the respective opening degrees of the first distribution control valve 21A and the second distribution control valve 26A, the flow rate of the first coolant flowing into the second heat exchanger 50 and the flow rate of the first cooling liquid flowing into the third heat exchanger 60 The flow rate of the second coolant can be adjusted.

In addition, the second cooling liquid circulation device 30 includes a tank 34 in the middle of the return-side flow path 32 that stores a certain amount of the second cooling liquid, and a second cooling liquid that sucks and discharges the second cooling liquid in the tank 34 . and a liquid pump 33 . The return-side flow path 32 is connected to the third heat exchanger 60 at a portion between the second coolant pump 33 and the second heat exchanger 50 . The tank 34 is also connected to a high-temperature flow path 35 through which the second cooling liquid in the tank 34 flows, and the high-temperature flow path 35 has a heater 36 that heats the second cooling liquid to flow through.

On the other hand, the supply-side channel 31 is provided with a low-temperature control valve 31A. The low-temperature control valve 31A controls flow rate control and blockage of the second coolant flowing through the supply-side channel 31 toward the temperature controlled object. Further, the intermediate temperature flow path 37 is connected to a position in the return side flow path 32 on the downstream side of the third heat exchanger 60 and on the upstream side of the second heat exchanger 50 . An intermediate temperature control valve 38 is provided in the intermediate temperature flow path 37 . In the present embodiment, by providing the plurality of flow paths and valves described above, for example, a pattern in which the low-temperature second cooling liquid is supplied from the supply-side flow path 31 to the temperature control target, and a pattern in which the low-temperature second cooling liquid is supplied from the medium-temperature flow path 37 A pattern of supplying a second cooling liquid having a higher temperature than the low temperature second cooling liquid to a temperature controlled object, and a second cooling liquid flowing from a high temperature flow path 35 to an intermediate temperature flow path 37 to a temperature controlled object. It is possible to switch between a pattern of supplying the second cooling liquid having a higher temperature.

In the fifth embodiment described above, the second coolant is cooled in stages by the third heat exchanger 60 and the second heat exchanger 50, so that the first coolant in the second heat exchanger 50 By suppressing the temperature difference between the second cooling liquid and the second cooling liquid, the load on the second heat exchanger 50 can be reduced, and highly reliable operation can be performed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, the embodiments described below can also be adopted.

<Other embodiments>
In the embodiment shown in FIG. 6, the first cooling liquid circulating device 20 in the cooling system S2 according to the second embodiment includes a flow control passage 28 and a flow control valve 29 provided in the flow control passage 28. It is different from the second embodiment in that it further includes The flow control flow path 28 is connected to the upstream side and the downstream side of the portion of the second flow path 22 connected to the internal heat exchanger 24 . The flow rate control valve 29 adjusts the flow rate of the first coolant discharged from the second heat exchanger 50 and flowing through the flow rate control channel 28 . The opening degree of the flow control valve 29 is controlled by a controller (not shown). The controller may be configured by a computer having a CPU, ROM, and the like.

Further, in the embodiment shown in FIG. 6, the temperature of the first coolant flowing through the portion of the first flow path 21 downstream of the internal heat exchanger 24 and upstream of the second heat exchanger 50 is A first temperature sensor 71 is provided for detection. In addition, the second coolant flowing device 30 is provided with a second coolant flowing through a portion of the supply-side channel 31 downstream of the connection with the second heat exchanger 50 and upstream of the temperature controlled target. A second temperature sensor 72 is provided to detect the temperature of the .

In the embodiment shown in FIG. 6, when the temperature of the first coolant detected by the first temperature sensor 71 is higher than the predetermined first coolant target temperature, the opening degree of the flow control valve 29 is increased. When the temperature of the first coolant detected by the first temperature sensor 71 is lower than the first coolant target temperature, the degree of opening of the flow rate control valve 29 is reduced. Thus, the flow control valve 29 can be controlled. Alternatively, in the embodiment shown in FIG. 6, when the temperature of the second coolant detected by the second temperature sensor 72 is higher than the predetermined second coolant target temperature, the opening degree of the flow control valve 29 is increased. When the temperature of the second coolant detected by the second temperature sensor 72 is lower than the second coolant target temperature, the opening degree of the flow rate control valve 29 is reduced. It is also possible to control the flow control valve 29 in this manner. This makes it easier to control the temperature of the object to be temperature-controlled at a desired temperature while suppressing energy consumption. In particular, according to the latter, when the temperature of the second coolant that has exchanged heat with the object to be temperature-controlled undergoes large temperature fluctuations, it is possible to effectively improve the responsiveness of the temperature control.

In the embodiment shown in FIG. 7, the first coolant circulation device 20 in the cooling system S3 according to the third embodiment further includes a flow control valve 25A provided in the bypass flow path 25. 3 embodiment. The flow control valve 25A adjusts the flow rate of the first cooling liquid that flows through the bypass flow path 25. As shown in FIG. The opening degree of the flow control valve 25A is controlled by a controller (not shown). The controller may be configured by a computer having a CPU, ROM, and the like.

Also, in the embodiment shown in FIG. 7, a first temperature sensor 71 and a second temperature sensor 72 are provided in the same manner as in the configuration shown in FIG. However, the first temperature sensor 71 detects the temperature of the first coolant flowing through a portion of the first flow path 21 downstream of the connection position with the bypass flow path 25 .

In the embodiment shown in FIG. 7, when the temperature of the first coolant detected by the first temperature sensor 71 is higher than the predetermined first coolant target temperature, the opening degree of the flow control valve 25A is reduced. When the temperature of the first coolant detected by the first temperature sensor 71 is lower than the first coolant target temperature, the opening degree of the flow rate control valve 25A is increased. Thus, the flow control valve 25A can be controlled. Alternatively, in the embodiment shown in FIG. 7, when the temperature of the second coolant detected by the second temperature sensor 72 is higher than the predetermined second coolant target temperature, the opening degree of the flow control valve 25A is reduced. When the temperature of the second coolant detected by the second temperature sensor 72 is lower than the second coolant target temperature, the opening degree of the flow rate control valve 25A is increased. It is also possible to control the flow control valve 25A in this manner. This makes it easier to control the temperature of the object to be temperature-controlled at a desired temperature while suppressing energy consumption. In particular, according to the latter, the responsiveness of the temperature control can be effectively improved when the temperature of the second coolant that has exchanged heat with the object to be temperature-controlled undergoes large temperature fluctuations.

Claims

a refrigeration cycle device that circulates a natural refrigerant;
a first cooling liquid circulation device for circulating a first cooling liquid cooled by the natural refrigerant;
and a second cooling liquid flow device for causing flow of a second cooling liquid cooled by the first cooling liquid circulated by the first cooling liquid circulation device.
The cooling system according to claim 1, wherein the type of the first cooling liquid and the type of the second cooling liquid are different.
The refrigeration cycle device and the first coolant circulation device are connected by a first heat exchanger, and the first coolant is cooled by the natural refrigerant in the first heat exchanger,
The first coolant circulation device and the second coolant circulation device are connected by a second heat exchanger, and the second coolant is cooled by the first coolant in the second heat exchanger,
The first cooling liquid circulation device is a first heat exchanger that connects a discharge port of the first heat exchanger that discharges the first cooling liquid and a receiving port of the second heat exchanger that receives the first cooling liquid. a second flow path connecting a flow path, a discharge port of the second heat exchanger that discharges the first cooling liquid, and a receiving port of the first heat exchanger that receives the first cooling liquid; 2. The cooling system according to claim 1, comprising a pump that generates driving force for circulating the first cooling liquid.
The first flow path and the second flow path are connected by an internal heat exchanger, and in the internal heat exchanger, the heat is discharged from the discharge port of the first heat exchanger to the reception port of the second heat exchanger. 4. The method according to claim 3, wherein heat is exchanged between the first cooling liquid before being received and the first cooling liquid discharged from the discharge port of the second heat exchanger and before being received by the receiving port of the first heat exchanger. Cooling system as described.
4. The cooling system according to claim 3, wherein the first cooling liquid circulation device further has a bypass flow path that connects the first flow path and the second flow path and allows the first cooling liquid to flow.
The first cooling liquid circulation device includes a branch flow path branched from the second flow path and connected to the second flow path at a position upstream of the branched position, and a second flow path provided on the branch flow path. 4. The cooling system of claim 3, further comprising: 3 heat exchangers.
A third cooling liquid circulation device for causing a third cooling liquid to flow is connected to the third heat exchanger,
7. The cooling system of claim 6, wherein in said third heat exchanger said third coolant is cooled by said first coolant.
The second coolant flow device is connected to the third heat exchanger,
7. The cooling system according to claim 6, wherein said second coolant is cooled by said second heat exchanger after being cooled by said third heat exchanger.
The first cooling liquid is silicone oil,
2. The cooling system of claim 1, wherein said second cooling liquid is an ether-based liquid.
The cooling system according to claim 1, wherein the refrigeration cycle device is an air refrigeration cycle device.