Heat transfer medium and heat transfer system using the same

Abstract

The heat transfer system transfers the cold and heat of the refrigerant circulating in the refrigeration cycle device (10) to the electrical equipment (33-35). The heat transfer medium is used in the heat transfer system. The heat transfer medium contains a lower alcohol and water, and the lower alcohol is at least one of methanol and ethanol.

Description

[0001] Cross-references of related applications

[0002] This application is based on Japanese Patent Application No. 2019-58287 filed on March 26, 2019, Japanese Patent Application No. 2019-58288 filed on March 26, 2019, Japanese Patent Application No. 2019-58289 filed on March 26, 2019, and Japanese Patent Application No. 2019-58290 filed on March 26, 2019, and the contents thereof are cited herein. Technical Field

[0003] The present invention relates to a heat transport medium and a heat transport system for transporting heat through the heat transport medium. Background Art

[0004] Patent Document 1 describes a device for cooling low-temperature cooling water by exchanging heat between a refrigerant in a refrigeration cycle and low-temperature cooling water in a low-temperature cooling water circuit by a chiller. In this device, ethylene glycol aqueous solution or the like is used as the low-temperature cooling water.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2017-110898

[0008] However, the viscosity of the ethylene glycol aqueous solution increases at low temperatures, so the pressure loss in the low-temperature cooling water circuit increases, which leads to an increase in the pump power for circulating the low-temperature cooling water. Summary of the invention

[0009] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to suppress an increase in viscosity of a heat transfer medium at a low temperature.

[0010] In order to achieve the above-mentioned object, a heat transfer medium in one embodiment of the present invention is used in a heat transfer system which transfers heat and cold of a refrigerant circulating in a refrigeration cycle device to an electrical device, wherein the heat transfer medium contains a lower alcohol and water, wherein the lower alcohol is at least one of methanol and ethanol.

[0011] In this way, by using a heat transfer medium containing a lower alcohol such as at least one of methanol and ethanol and water, it is possible to suppress an increase in viscosity in a low-temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram showing the configuration of the heat transport system according to the first embodiment.

[0013] Figure 2 It is a front view which shows the 2nd cooler in 1st Embodiment.

[0014] Figure 3 It is a characteristic diagram showing the relationship between temperature and kinematic viscosity in Examples and Comparative Examples of the first embodiment.

[0015] Figure 4 This is a characteristic diagram showing the relationship between the pressure loss of the low-temperature-side heat transfer medium and the heat transfer coefficient ratio in the second cooler according to the first embodiment.

[0016] Figure 5 It is an explanatory diagram showing the temperature state inside the second cooler.

[0017] Figure 6 It is an explanatory diagram showing the freezing point and boiling point in Examples and Comparative Examples 1 to 3 of the second embodiment.

[0018] Figure 7 It is an explanatory diagram showing the freezing point and boiling point in Examples and Comparative Examples 1 to 3 of the third embodiment.

[0019] Figure 8 It is a characteristic diagram showing the relationship between temperature and kinematic viscosity in Example 1 and Comparative Example 1 of the fourth embodiment.

[0020] Fig. 9 It is a graph showing the electrical conductivity in Example 2 and Comparative Example 2 of the fourth embodiment. DETAILED DESCRIPTION

[0021] Hereinafter, with reference to the accompanying drawings, a plurality of methods for implementing the present invention will be described. In each embodiment, the same reference numerals may be used to mark the parts corresponding to the matters described in the previous embodiment, and repeated descriptions may be omitted. In the case where only a part of the structure is described in each embodiment, other embodiments previously described can be applied to the other parts of the structure. In addition to the combination of the parts that can be combined is specifically indicated in each embodiment, as long as there is no special obstacle to the combination, the embodiments can be partially combined with each other even if it is not indicated.

[0022] (First Embodiment)

[0023] Hereinafter, a first embodiment of the present invention will be described based on the accompanying drawings. The heat transport system of this embodiment is mounted on an electric vehicle that obtains the driving force for the vehicle from the driving motor. The heat transport system may also be mounted on a hybrid vehicle that obtains the driving force for the vehicle from the engine (in other words, the internal combustion engine) and the driving motor. The heat transport system of this embodiment functions as an air conditioning device that adjusts the temperature of the interior space of the vehicle, and also functions as a temperature control device that adjusts the temperature of the battery 33 etc. mounted on the vehicle.

[0024] like Figure 1As shown, the heat transfer system includes: a refrigeration cycle device 10, a high temperature medium circuit 20 as a high temperature side heat transfer medium circuit, and a low temperature medium circuit 30 as a heat transfer medium circuit. In the high temperature medium circuit 20 and the low temperature medium circuit 30, heat is transferred by the heat transfer medium. The temperature of the heat transfer medium of the low temperature medium circuit 30 is lower than that of the heat transfer medium of the high temperature medium circuit 20. Therefore, the heat transfer medium of the high temperature medium circuit 20 can also be referred to as the high temperature side heat transfer medium, and the heat transfer medium of the low temperature medium circuit 30 can also be referred to as the low temperature side heat transfer medium.

[0025] The refrigeration cycle device 10 is a vapor compression refrigerator, and has a refrigerant circulation flow path 11 in which a refrigerant circulates. The refrigeration cycle device 10 functions as a heat pump that extracts heat from a low-temperature side heat transfer medium of a low-temperature medium circuit 30 into the refrigerant.

[0026] In the refrigeration cycle device 10 of the present embodiment, a Freon-based refrigerant is used as a refrigerant, and a subcritical refrigeration cycle is formed in which the refrigerant pressure on the high-pressure side does not exceed the critical pressure of the refrigerant. The refrigerant circulation flow path 11 is provided with: a compressor 12, a condenser 13 as a heating heat exchanger, an expansion valve 14, and an evaporator 15 for heat transfer medium as a cooling heat exchanger.

[0027] The compressor 12 is an electric compressor driven by the power supplied from the battery 33, and sucks in the refrigerant, compresses it, and then discharges it. The condenser 13 is a high-pressure side heat exchanger that condenses the high-pressure side refrigerant by exchanging heat between the high-pressure side refrigerant discharged from the compressor 12 and the heat transfer medium of the high-temperature medium circuit 20. In the condenser 13, the heat transfer medium of the high-temperature medium circuit 20 is heated by the high-pressure side refrigerant of the refrigeration cycle device 10.

[0028] The expansion valve 14 is a decompression unit that decompresses and expands the liquid-phase refrigerant flowing out of the condenser 13. The expansion valve 14 is a mechanical temperature-type expansion valve that has a temperature sensing unit and drives a valve element by a mechanical mechanism such as a diaphragm.

[0029] The heat transfer medium evaporator 15 is a low-pressure side heat exchanger that evaporates the low-pressure refrigerant flowing out of the expansion valve 14 by exchanging heat with the heat transfer medium of the low-temperature medium circuit 30. The gas-phase refrigerant evaporated in the heat transfer medium evaporator 15 is sucked into the compressor 12 and compressed.

[0030] The heat transfer medium evaporator 15 is a refrigerator for cooling the heat transfer medium of the low temperature medium circuit 30 by the low pressure refrigerant of the refrigeration cycle device 10. In the heat transfer medium evaporator 15, the refrigerant of the refrigeration cycle device 10 absorbs heat from the heat transfer medium of the low temperature medium circuit 30.

[0031] The high temperature medium circuit 20 has a high temperature side circulation flow path 21 for circulating the high temperature side heat transfer medium. As the high temperature side heat transfer medium, an ethylene glycol-based antifreeze (LLC) or the like can be used. The high temperature side heat transfer medium is sealed in the piping constituting the high temperature side circulation flow path 21. The high temperature medium circuit 20 of this embodiment is a closed type without a pressure regulating valve that opens when the pressure of the high temperature side heat transfer medium exceeds a specified value. That is, the high temperature medium circuit 20 of this embodiment is closed.

[0032] A high temperature side pump 22 , a heater core 23 , and a condenser 13 are arranged in the high temperature side circulation flow path 21 .

[0033] The high temperature side pump 22 sucks and discharges the heat transfer medium circulating in the high temperature side circulation flow path 21. The high temperature side pump 22 is an electric pump. The high temperature side pump 22 adjusts the flow rate of the heat transfer medium circulating in the high temperature medium circuit 20.

[0034] The heater core 23 is an air heating heat exchanger that heats the air blown into the vehicle interior by exchanging heat between the heat transfer medium in the high temperature medium circuit 20 and the air blown into the vehicle interior. In the heater core 23, the air blown into the vehicle interior is heated by the heat transfer medium.

[0035] The air heated by the heater core 23 is supplied to the vehicle interior, thereby heating the vehicle interior. Heating by the heater core 23 is mainly performed in winter. In the heat transfer system of this embodiment, the heat of the outside air absorbed by the low-temperature side heat transfer medium of the low-temperature medium circuit 30 is absorbed by the high-temperature side heat transfer medium of the high-temperature medium circuit 20 through the refrigeration cycle device 10 and used for indoor heating.

[0036] The low temperature medium circuit 30 has a low temperature side circulation flow path 31 for circulating the low temperature side heat transfer medium. The low temperature side heat transfer medium is sealed in the piping constituting the low temperature side circulation flow path 31. The low temperature medium circuit 30 of this embodiment is a closed type without a pressure regulating valve that opens when the pressure of the low temperature side heat transfer medium exceeds a specified value. That is, the low temperature medium circuit 30 of this embodiment is closed. In addition, the low temperature side heat transfer medium will be described later.

[0037] The low temperature side circulation flow path 31 is provided with a low temperature side pump 32, a heat transfer medium evaporator 15, a battery 33, an inverter (INV) 34, a motor generator (MG) 35, and an outdoor heat exchanger 36. Figure 1 In the example shown, the battery 33, the inverter 34, the motor generator 35, the outdoor heat exchanger 36, and the low temperature side pump 32 are connected in sequence in the flow direction of the low temperature side heat transfer medium, but the connection order is not limited to this. Figure 1In the example shown, the battery 33, the inverter 34, the motor generator 35, the outdoor heat exchanger 36, and the low-temperature side pump 32 are connected in series, but one or more of these devices may be connected in parallel with the other devices.

[0038] The low temperature side pump 32 sucks and discharges the heat transfer medium circulating in the low temperature side circulation flow path 31. The low temperature side pump 32 is an electric pump. The low temperature side pump 32 adjusts the flow rate of the heat transfer medium circulating in the low temperature medium circuit 30.

[0039] The battery 33 is a secondary battery that can be charged and discharged, and a lithium ion battery can be used, for example. As the battery 33, a battery pack composed of a plurality of battery elements can be used.

[0040] The battery 33 can be charged with power supplied from an external power source (in other words, a commercial power source) when the vehicle is parked. The power stored in the battery 33 is supplied not only to the travel motor but also to various vehicle-mounted devices represented by electric structural devices constituting the heat transport system.

[0041] The inverter 34 converts the DC power supplied from the battery 33 into AC power and outputs the AC power to the motor generator 35. The motor generator 35 generates a driving force for running using the power output from the inverter 34, and generates regenerative power during deceleration or downhill driving.

[0042] The outdoor heat exchanger 36 exchanges heat between the heat transfer medium in the low-temperature medium circuit 30 and the outside air. The outside air is blown to the outdoor heat exchanger 36 by an outdoor blower (not shown).

[0043] The battery 33, the inverter 34, and the motor generator 35 are electrical devices that use electricity to operate and generate heat when operating. The battery 33, the inverter 34, and the motor generator 35 are cooling target devices that are cooled by the low-temperature side heat transfer medium.

[0044] The low temperature side circulation flow path 31 of the present embodiment is provided with coolers 37 to 39 corresponding to the electric devices 33 to 35 . The first cooler 37 corresponds to the battery 33 , the second cooler 38 corresponds to the inverter 34 , and the third cooler 39 corresponds to the motor generator 35 .

[0045] The low-temperature-side heat transfer medium flows through the coolers 37 to 39. The electrical devices 33 to 35 are cooled by the low-temperature-side heat transfer medium flowing through the coolers 37 to 39.

[0046] In the first cooler 37 and the second cooler 38, the battery 33 and the inverter 34 are cooled by the low temperature side heat transfer medium without passing through other heat transfer media. The third cooler 39 is an oil cooler that cools the oil circulating in the oil circuit 40 by the low temperature side heat transfer medium. The oil flows inside the motor generator 35, thereby lubricating and cooling the motor generator 35.

[0047] In the coolers 37 to 39, heat is absorbed from the battery 33, the inverter 34, and the motor generator 35, which are cooling target devices, to the low-temperature side heat transfer medium. In the outdoor heat exchanger 36, heat is absorbed from the outside air to the low-temperature side heat transfer medium. That is, the battery 33, the inverter 34, the motor generator 35, and the outdoor heat exchanger 36 are heat-absorbing devices that absorb heat to the low-temperature side heat transfer medium.

[0048] Next, the specific structure of the second cooler 38 will be described. Figure 2 As shown, the second cooler 38 of the present embodiment is a stacked heat exchanger that cools the plurality of electronic components 340 constituting the inverter 34 from both sides.

[0049] The electronic component 340 of this embodiment has a double-sided heat dissipation structure that dissipates heat from both sides. As the electronic component 340, a semiconductor module having a semiconductor element such as an IGBT and a diode built therein can be used.

[0050] The second cooler 38 includes a flow tube 381 and a communication portion 382. The flow tube 381 is formed in a flat shape and constitutes a low-temperature heat transfer medium flow path for flowing the low-temperature heat transfer medium of the low-temperature medium circuit 30. A plurality of flow tubes 381 are stacked so as to sandwich the electronic component 340 from both sides.

[0051] The communication portion 382 allows the plurality of flow tubes 381 to communicate with each other. The communication portion 382 is connected to both ends of the flow tube 381 in the longitudinal direction.

[0052] In the present embodiment, two electronic components 340 are provided for each flat surface of the flow tube 381. The two electronic components 340 provided on each flat surface are arranged in series in the flow direction of the low temperature side heat transfer medium.

[0053] Here, the outermost flow pipe 381 in the stacking direction among the plurality of flow pipes 381 is referred to as an outer flow pipe 3810. One of the two outer flow pipes 3810 in the second cooler 38 has an inlet 383 and an outlet 384 at both ends in the longitudinal direction.

[0054] The inlet 383 is an inlet portion for introducing the low temperature side heat transfer medium into the second cooler 38. The outlet 384 is an outlet portion for discharging the low temperature side heat transfer medium from the second cooler 38. The inlet 383 and the outlet 384 are joined to one of the outer flow pipes 3810 by brazing. The flow pipe 381, the connecting portion 382, ​​the inlet 383 and the outlet 384 of this embodiment are respectively made of aluminum.

[0055] The low-temperature side heat transfer medium introduced from the inlet 383 flows into each flow tube 381 from one end in the longitudinal direction of the flow tube 381 through the one connecting portion 382, ​​and flows toward the other end in each flow tube 381. Then, the low-temperature side heat transfer medium passes through the other connecting portion 382 and is discharged from the discharge port 384. Thus, while the low-temperature side heat transfer medium flows in the flow tube 381, heat exchange is performed between the low-temperature side heat transfer medium and the electronic component 340, thereby cooling the electronic component 340.

[0056] Next, the low temperature side heat transfer medium will be described. The low temperature side heat transfer medium preferably has a low viscosity at low temperatures and high cooling performance.

[0057] In this embodiment, a methanol aqueous solution containing methanol and water is used as the low temperature side heat transfer medium. In this embodiment, the amount of water in the low temperature side heat transfer medium is greater than the amount of methanol. That is, the proportion of water in the methanol aqueous solution is greater than 50%.

[0058] Specifically, the weight ratio of methanol to water in the low temperature side heat transfer medium is methanol:water=35:65 to 50:50. That is, the weight ratio of methanol to water in the low temperature side heat transfer medium is set to a range of 35:65 or more and 50:50 or less.

[0059] Here, in Figure 3 1 and 2 show the relationship between temperature and kinematic viscosity in a methanol aqueous solution (methanol:water=35:65 to 50:50) as an example and an ethylene glycol antifreeze solution (LLC) as a comparative example.

[0060] like Figure 3 As shown by the solid line, the dynamic viscosity of the methanol aqueous solution as an example at -20°C is 10.0 mm 2 / s, the dynamic viscosity at -35℃ is 24.2mm 2 / s. Figure 3 As shown by the dotted line, the ethylene glycol antifreeze liquid as a comparative example has a kinematic viscosity of 29.6 mm at -20°C. 2 / s, the dynamic viscosity at -35℃ is 89.5mm 2 / s. In this way, the methanol aqueous solution can ensure low viscosity at low temperatures.

[0061] Here, in Figure 4 Graph 2 shows the relationship between the pressure loss of the low-temperature side heat transfer medium in the second cooler 38 and the heat transfer coefficient ratio when the temperature of the low-temperature side heat transfer medium is 25° C. Figure 4 The heat transfer ratio shown on the vertical axis is a value of the heat transfer ratio when the ethylene glycol antifreeze of the comparative example is used as the low-temperature side heat transfer medium and the heat transfer ratio when the pressure loss of the low-temperature side heat transfer medium in the second cooler 38 is 35 kPa is expressed as 1.0.

[0062] exist Figure 4 In FIG. 1 , the solid line shows the relationship between the pressure loss and the heat transfer rate ratio when the methanol aqueous solution of the embodiment is used as the low temperature side heat transfer medium. Figure 4 In FIG. 1 , the relationship between the pressure loss and the heat transfer rate ratio when the ethylene glycol antifreeze liquid of the comparative example is used as the low-temperature-side heat transfer medium is indicated by a dotted line.

[0063] like Figure 4 As shown, under the condition that the low-temperature side heat transfer medium is 25°C, when a methanol aqueous solution is used as the low-temperature side heat transfer medium, the pressure loss can be reduced by 50% under the same performance (i.e., the same heat transfer rate) compared to the case of using an ethylene glycol antifreeze liquid as the low-temperature side heat transfer medium.

[0064] Here, if Figure 3 As shown in Figure 1, at 25°C, the kinematic viscosity of the methanol aqueous solution is about 1 / 2 of that of the ethylene glycol antifreeze solution. On the other hand, at -35°C, the kinematic viscosity of the methanol aqueous solution is about 1 / 4 of that of the ethylene glycol antifreeze solution.

[0065] Therefore, it can be considered that when methanol aqueous solution is used as the low temperature side heat transfer medium at -35°C, the pressure loss can be further reduced by 50% compared with the case where ethylene glycol antifreeze is used as the low temperature side heat transfer medium. In this way, when methanol aqueous solution is used as the low temperature side heat transfer medium, the pressure loss in low temperature can be suppressed to a low level.

[0066] In addition, if Figure 4 As shown, under the condition that the low temperature side heat transfer medium is 25°C, when the methanol aqueous solution is used as the low temperature side heat transfer medium, the heat transfer rate can be increased by 20% under the same pressure loss compared with the case where the ethylene glycol antifreeze liquid is used as the low temperature side heat transfer medium. In this way, when the methanol aqueous solution is used as the low temperature side heat transfer medium, the heat transfer rate of the low temperature side heat transfer medium can be improved, and the cooling performance in the coolers 37 to 39 can be improved.

[0067] The low temperature side heat transfer medium of this embodiment contains a rust inhibitor in addition to water and methanol. The rust inhibitor is used to prevent corrosion of the pipes through which the low temperature side heat transfer medium flows. The concentration of the rust inhibitor in the low temperature side heat transfer medium can be appropriately set, and can be set to, for example, several percent.

[0068] As the rust inhibitor, at least one selected from aliphatic monocarboxylic acids, aromatic monocarboxylic acids, aromatic dicarboxylic acids or salts thereof, borates, silicates, silicic acid, phosphates, phosphoric acid, nitrites, nitrates, molybdates, triazoles and thiazoles can be used.

[0069] As described above, in this embodiment, a methanol aqueous solution containing methanol and water is used as the low-temperature side heat transfer medium. As a result, compared with ethylene glycol antifreeze, the viscosity increase in a low-temperature environment can be suppressed. Therefore, even in a low-temperature environment, the increase in pressure loss in the low-temperature medium circuit 30 can be suppressed, and the increase in power of the low-temperature side pump 32 can be suppressed.

[0070] In addition, in the outdoor heat exchanger 36, the flow path of the low temperature side heat transfer medium is set narrow and the outdoor heat exchanger 36 can be easily miniaturized, which can increase the degree of freedom in design. In addition, since the flow rate of the low temperature side heat transfer medium passing through the outdoor heat exchanger 36 is increased, frost on the outdoor heat exchanger 36 can be suppressed.

[0071] In addition, since the viscosity increase of the low-temperature side heat transfer medium in a low-temperature environment can be suppressed, the flow rate of the low-temperature side heat transfer medium can be increased compared to the glycol-based antifreeze. As a result, the flow rate of the low-temperature side heat transfer medium can be increased, and the heat transfer rate of the low-temperature side heat transfer medium can be further increased. Moreover, by increasing the heat transfer rate of the low-temperature side heat transfer medium, the heat transfer rate of the entire device including the outdoor heat exchanger 36 can be increased.

[0072] In addition, in this embodiment, the amount of water contained in the low temperature side heat transfer medium is set to be greater than the amount of methanol. Compared with ethylene glycol antifreeze, the methanol aqueous solution can maintain a lower freezing point and increase the proportion of water. Therefore, in the methanol aqueous solution, by increasing the proportion of water with a larger heat capacity, the heat capacity of the low temperature side heat transfer medium can be increased, and the thermal conductivity can be further improved.

[0073] In addition, by increasing the proportion of water in the methanol aqueous solution, the viscosity of the low temperature side heat transfer medium can be further reduced. Furthermore, by increasing the proportion of water in the methanol aqueous solution, the cost of the low temperature side heat transfer medium can be reduced.

[0074] However, when the pipes through which the low-temperature side heat transfer medium flows are made of aluminum, the methanol contained in the low-temperature side heat transfer medium may chemically react with the aluminum constituting the pipes to generate aluminum alcohol. As a result, the amount of methanol contained in the low-temperature side heat transfer medium may decrease, thereby reducing the effect of suppressing the viscosity increase in a low-temperature environment. In other words, the freezing temperature may rise.

[0075] In contrast, by making the amount of water contained in the low-temperature side heat transfer medium greater than the amount of methanol as in the present embodiment, the proportion of water contained in the low-temperature side heat transfer medium is increased, and thus the generation of aluminum alcoholate can be suppressed. Thus, even when the pipes through which the low-temperature side heat transfer medium flows are made of aluminum, the increase in viscosity in a low-temperature environment can be reliably suppressed. That is, the rise in the freezing temperature can be suppressed.

[0076] Furthermore, by setting the weight ratio of methanol to water in the low temperature side heat transfer medium to 35:65 to 50:50, the freezing point of the low temperature side heat transfer medium can be set to -35°C or less. Therefore, freezing of the low temperature side heat transfer medium in a low temperature environment such as winter can be suppressed.

[0077] Furthermore, by making the low-temperature-side heat transfer medium contain a rust inhibitor, corrosion of the pipes through which the low-temperature-side heat transfer medium flows can be suppressed, thereby improving the durability of the heat transfer system.

[0078] (Second Embodiment)

[0079] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. The low-temperature-side heat transfer medium of the second embodiment preferably has a low viscosity at low temperatures and a high boiling point.

[0080] In this embodiment, a methanol aqueous solution containing methanol, water and a boiling point increasing agent is used as the low temperature side heat transfer medium. In this embodiment, the proportion of the boiling point increasing agent in the methanol aqueous solution is less than 50%.

[0081] As the boiling point raising agent, a substance which is compatible with both water and methanol and has a boiling point higher than that of a mixture of water and methanol can be used. Specifically, as the boiling point raising agent, at least any one of alcohol, amine, ether, and carboxylic acid can be used.

[0082] As the alcohol, at least one of an alcohol having one hydroxyl group and three or more carbon atoms and an alcohol having two or more hydroxyl groups and two or more carbon atoms can be used. As the alcohol having two or more hydroxyl groups and two or more carbon atoms, for example, at least one of ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol can be used.

[0083] As the amine, at least one of formamide and methylamine can be used. As the ether, at least one of dimethyl ether, ethyl methyl ether, diethyl ether, and ethylene glycol ether can be used. As the carboxylic acid, at least one of formic acid and acetic acid can be used.

[0084] like Figure 5 As shown, the heat generated by the electronic components 340 of the inverter 34 flows through the inner wall surface 381a of the flow pipe 381 and is transferred to the low-temperature side heat transfer medium. As a result, the temperature of the low-temperature side heat transfer medium flowing into the flow pipe 381 rises.

[0085] At this time, the temperature of the portion of the low-temperature side heat transfer medium flow path in the flow tube 381 that is opposite to the inner wall surface 381a becomes higher than the temperature of other portions. That is, the temperature of the portion of the low-temperature side heat transfer medium flow path in the flow tube 381 that is opposite to the inner wall surface 381a becomes the highest. Therefore, the temperature of the inner wall surface 381a of the flow tube 381 actually becomes the highest temperature of the low-temperature side heat transfer medium. Therefore, by making the boiling point of the low-temperature side heat transfer medium higher than the temperature of the inner wall surface 381a of the flow tube 381, it is possible to suppress the low-temperature side heat transfer medium from boiling in the flow tube 381.

[0086] In particular, in a high temperature environment such as summer, the temperature of the inverter 34 tends to rise, and the temperature of the inner wall surface 381a of the flow pipe 381 in the second cooler 38 becomes high. Therefore, the boiling point of the low temperature side heat transfer medium is preferably higher than the temperature of the inner wall surface 381a of the flow pipe 381 in summer (in this example, about 90°C). In addition, in order to suppress freezing in a low temperature environment such as winter, the freezing point of the low temperature side heat transfer medium is preferably -35°C or lower.

[0087] like Figure 6 As shown, the freezing point of anhydrous methanol as Comparative Example 1 is -95°C and the boiling point is 65°C. The freezing point of the methanol aqueous solution containing methanol and water (methanol:water=35:65) as Comparative Example 2 is -35°C and the boiling point is 82°C.

[0088] In contrast, in the methanol aqueous solution containing methanol, water and a boiling point increasing agent (methanol: water: boiling point increasing agent = 10:50:40) as an example, the freezing point is -35°C and the boiling point is 100°C. In this way, the methanol aqueous solution containing methanol, water and a boiling point increasing agent can ensure a high boiling point and a low freezing point. In addition, when the methanol aqueous solution containing methanol, water and a boiling point increasing agent as an example is sealed in the low-temperature medium circuit 30 at a high pressure, the boiling point of the methanol aqueous solution can be further increased.

[0089] The ethylene glycol antifreeze liquid (ethylene glycol: water = 50:50) of Comparative Example 3 has a freezing point of -35°C and a boiling point of 107°C. However, the ethylene glycol antifreeze liquid has a higher kinematic viscosity at -35°C than the methanol aqueous solution, and therefore cannot ensure a low viscosity at low temperatures.

[0090] The low temperature side heat transfer medium of this embodiment contains a rust inhibitor in addition to water, methanol and a boiling point raising agent. The concentration of the rust inhibitor in the low temperature side heat transfer medium can be appropriately set, but can be set to, for example, several percent. As the rust inhibitor, the same rust inhibitor as in the first embodiment can be used.

[0091] As described above, in this embodiment, a methanol aqueous solution containing methanol, water and a boiling point raising agent is used as a low temperature side heat transfer medium. Thus, compared with an ethylene glycol antifreeze solution, an increase in viscosity under a low temperature environment can be suppressed. Therefore, the same effect as the first embodiment can be obtained.

[0092] In addition, by making the low-temperature side heat transfer medium contain a boiling point raising agent, the boiling point of the low-temperature side heat transfer medium can be raised. Thus, even if the low-temperature side heat transfer medium is heated due to the heat load, boiling of the low-temperature side heat transfer medium in the low-temperature medium circuit 30 can be suppressed. Therefore, the state in which the low-temperature side heat transfer medium in the liquid phase does not exist in a part of the low-temperature medium circuit 30, that is, the occurrence of premature drying can be suppressed. Thus, in the heat transfer medium evaporator 15, heat exchange between the low-pressure refrigerant and the low-temperature side heat transfer medium can be stably performed.

[0093] In addition, in the present embodiment, the low temperature medium circuit 30 is a closed type. This allows the low temperature side heat transfer medium to be sealed in the low temperature medium circuit 30 at a high pressure, so that the boiling point of the low temperature side heat transfer medium can be further increased.

[0094] In addition, in this embodiment, the low temperature side heat transfer medium contains a rust inhibitor. This can suppress the corrosion of the pipes through which the low temperature side heat transfer medium flows, thereby improving the durability of the heat transfer system. Furthermore, the boiling point of the low temperature side heat transfer medium can be raised by the boiling point rise effect.

[0095] (Third Embodiment)

[0096] Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. The low-temperature-side heat transfer medium of the third embodiment preferably has a low viscosity at low temperatures and a high boiling point.

[0097] In this embodiment, an ethanol aqueous solution containing ethanol and water is used as the low temperature side heat transfer medium. In this embodiment, the amount of water in the low temperature side heat transfer medium is set to be greater than the amount of ethanol. That is, the proportion of water in the ethanol aqueous solution is greater than 50%.

[0098] Specifically, the ratio of ethanol to water in the low temperature side heat transfer medium is set to ethanol:water=35:65 to 50:50 by weight. That is, the ratio of ethanol to water in the low temperature side heat transfer medium is set to a range of 35:65 or more and 50:50 or less by weight. In addition, it is preferred that the ratio of ethanol to water in the low temperature side heat transfer medium is set to ethanol:water=43:57 to 50:50 by weight.

[0099] like Figure 7 As shown, the freezing point of anhydrous methanol as Comparative Example 1 is -95°C and the boiling point is 65°C. The freezing point of the methanol aqueous solution containing methanol and water (methanol:water=35:65) as Comparative Example 2 is -35°C and the boiling point is 82°C.

[0100] In contrast, the ethanol aqueous solution containing ethanol and water (ethanol:water=45:55) as an example has a freezing point of -35°C and a boiling point of 82°C. Thus, the ethanol aqueous solution can ensure the same high boiling point and low freezing point as those of Comparative Example 2.

[0101] Furthermore, according to this embodiment, since ethanol is used as the freezing point depressant, the safety is higher than that of Comparative Example 2. Therefore, in the scenario of cooling water delivery / replenishment, the cooling water can be easily processed compared to Comparative Example 2. In addition, when the ethanol aqueous solution is sealed in the low-temperature medium circuit 30 at a high pressure, the boiling point of the ethanol aqueous solution can be further increased.

[0102] The ethylene glycol antifreeze liquid (ethylene glycol (EG): water = 50:50) of Comparative Example 3 has a freezing point of -35°C and a boiling point of 107°C. However, the kinetic viscosity of the ethylene glycol antifreeze liquid at -35°C is higher than that of the ethanol aqueous solution, so low viscosity at low temperatures cannot be ensured.

[0103] The low temperature side heat transfer medium of this embodiment contains a rust inhibitor in addition to water and ethanol. The concentration of the rust inhibitor in the low temperature side heat transfer medium can be appropriately set, but can be set to, for example, several percent. As the rust inhibitor, the same rust inhibitor as in the first embodiment can be used.

[0104] As described above, in this embodiment, an ethanol aqueous solution containing ethanol and water is used as the low-temperature side heat transfer medium. Thus, compared with ethylene glycol antifreeze, the viscosity increase under low-temperature environment can be suppressed. Therefore, the same effect as the first embodiment can be obtained.

[0105] Furthermore, by using ethanol aqueous solution as the low temperature side heat transfer medium, the boiling point of the low temperature side heat transfer medium can be increased. Specifically, the boiling point of the low temperature side heat transfer medium can be made higher than the temperature of the inner wall surface 381a of the flow tube 381 in summer.

[0106] Thus, even if the low-temperature side heat transfer medium is heated by the heat load, boiling of the low-temperature side heat transfer medium in the low-temperature medium circuit 30 (specifically, the flow pipe 381 of the second cooler 38) can be suppressed. Therefore, the state in which the low-temperature side heat transfer medium in liquid phase does not exist in a part of the low-temperature medium circuit 30, that is, the occurrence of premature drying can be suppressed. Thus, in the heat transfer medium evaporator 15, heat exchange between the low-pressure refrigerant and the low-temperature side heat transfer medium can be stably performed.

[0107] In addition, in this embodiment, the amount of water contained in the low temperature side heat transfer medium is set to be greater than the amount of ethanol. Compared with the ethylene glycol antifreeze, the ethanol aqueous solution can maintain a lower freezing point and increase the proportion of water. Therefore, in the ethanol aqueous solution, the proportion of water with a larger heat capacity can be increased, the heat capacity of the low temperature side heat transfer medium can be increased, and the thermal conductivity can be further improved.

[0108] In addition, by increasing the proportion of water in the ethanol aqueous solution, the viscosity of the low-temperature side heat transfer medium can be further reduced. In addition, by increasing the proportion of water in the ethanol aqueous solution, the cost of the low-temperature side heat transfer medium can be reduced.

[0109] However, when the pipes through which the low-temperature side heat transfer medium flows are made of aluminum, the ethanol contained in the low-temperature side heat transfer medium may chemically react with the aluminum constituting the pipes to generate aluminum alcohol. As a result, the amount of ethanol contained in the low-temperature side heat transfer medium may decrease, thereby reducing the effect of suppressing the viscosity increase in a low-temperature environment. In other words, the freezing temperature may rise.

[0110] In contrast, by setting the amount of water contained in the low-temperature side heat transfer medium to be greater than the amount of ethanol as in the present embodiment, the proportion of water contained in the low-temperature side heat transfer medium is increased, and the generation of aluminum alcoholate can be suppressed. Thus, even when the pipe through which the low-temperature side heat transfer medium flows is composed of aluminum, the increase in viscosity in a low-temperature environment can be reliably suppressed. That is, the rise in the freezing temperature can be suppressed.

[0111] Furthermore, by setting the weight ratio of ethanol to water in the low temperature side heat transfer medium to 43:57 to 50:50, the freezing point of the low temperature side heat transfer medium can be set to -35°C or lower. Therefore, freezing of the low temperature side heat transfer medium in a low temperature environment such as winter can be suppressed.

[0112] In addition, in this embodiment, the low-temperature side heat transfer medium contains a rust inhibitor. This can suppress the corrosion of the pipes through which the low-temperature side heat transfer medium flows, thereby improving the durability of the heat transfer system. Furthermore, the boiling point of the low-temperature side heat transfer medium can be raised by the boiling point rise effect.

[0113] In addition, in the present embodiment, the low temperature medium circuit 30 is a closed type. This allows the low temperature side heat transfer medium to be sealed in the low temperature medium circuit 30 at a high pressure, so that the boiling point of the low temperature side heat transfer medium can be further increased.

[0114] (Fourth Embodiment)

[0115] Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. The low-temperature-side heat transfer medium of the fourth embodiment preferably has low viscosity at low temperatures and low electrical conductivity.

[0116] The low temperature side heat transfer medium of this embodiment contains a lower alcohol which is at least one of methanol and ethanol, water, and a nonionic rust inhibitor. Hereinafter, in this specification, at least one of methanol and ethanol is referred to as a lower alcohol.

[0117] Here, methanol has a melting point of -97° C. and a boiling point of 64.5° C. Ethanol has a melting point of -114° C. and a boiling point of 78.3° C. As the lower alcohol, an alcohol having appropriate properties may be appropriately selected from methanol and ethanol depending on the use environment and the like.

[0118] In this embodiment, the amount of water in the low temperature side heat transfer medium is set to be equal to or greater than the amount of lower alcohol. That is, the ratio of water in the low temperature side heat transfer medium is set to be equal to or greater than 50%.

[0119] Specifically, the weight ratio of the lower alcohol to water in the low temperature side heat transfer medium is set to lower alcohol:water=35:65 to 50:50. That is, the weight ratio of the lower alcohol to water in the low temperature side heat transfer medium is set to be greater than 35:65 and less than 50:50.

[0120] Here, in Figure 8 The relationship between temperature and kinematic viscosity in a methanol aqueous solution (methanol:water=35:65 to 50:50) as Example 1 and an ethylene glycol antifreeze liquid (LLC) as Comparative Example 1 is shown in FIG.

[0121] like Figure 8 As shown by the solid line, the dynamic viscosity of the methanol aqueous solution of Example 1 at -20°C is 10.0 mm 2 / s, dynamic viscosity at -35°C is 24.2mm 2 / s. Figure 8As shown by the dotted line, the ethylene glycol antifreeze liquid of Comparative Example 1 has a kinematic viscosity of 29.6 mm at -20°C. 2 / s, dynamic viscosity at -35°C is 89.5mm 2 / s. In this way, the methanol aqueous solution can ensure low viscosity at low temperatures. Similarly, even the ethanol aqueous solution can ensure low viscosity at low temperatures.

[0122] The nonionic rust inhibitor contained in the low temperature side heat transfer medium is used to prevent corrosion of the pipes through which the low temperature side heat transfer medium flows. The concentration of the nonionic rust inhibitor in the low temperature side heat transfer medium can be appropriately set, but can be set to, for example, several percent. Furthermore, the nonionic rust inhibitor does not exhibit ionicity even when dissolved in water, and thus can suppress the increase in the conductivity of the low temperature side heat transfer medium.

[0123] As the nonionic rust inhibitor, Si ether and / or triazole-based rust inhibitors can be used. By using Si ether as the nonionic rust inhibitor, a film can be formed on the surface of aluminum. By using triazole as the nonionic rust inhibitor, a film can be formed on the surface of copper.

[0124] As the Si ether, those represented by the following general formula (1) can be used.

[0125] [Chemistry 1]

[0126]

[0127] In the general formula (1), R 1 ~R 4 R each independently represents a substituent. 1 ~R 4 A water-insoluble substituent is preferred. This allows the film formed by Si ether to have water-repellent properties and prevents water from being adsorbed on the surface of the aluminum pipe. Therefore, corrosion of the pipe can be effectively suppressed. In the general formula (1), R 1 ~R 4 For example, a hydrocarbon group or a halogenated hydrocarbon group in which a hydrogen atom of the hydrocarbon group is replaced by a halogen atom can be used.

[0128] Fig. 9 Graph showing the electrical conductivity in the low temperature side heat transfer medium of Example 2 and Comparative Example 2. In Example 2, the nonionic rust inhibitor of the present embodiment (i.e., Si ether and / or triazole-based rust inhibitor) was used as the rust inhibitor. In Comparative Example 2, sebacic acid, which is an ionic rust inhibitor, was used as the rust inhibitor.

[0129] like Fig. 9 As shown, when a nonionic rust inhibitor is used as a rust inhibitor, lower electrical conductivity can be obtained compared to when an ionic rust inhibitor is used as a rust inhibitor.

[0130] As described above, in this embodiment, as the low-temperature side heat transfer medium, a low-alcohol aqueous solution containing at least one of methanol and ethanol, water, and a non-ionic rust inhibitor is used. Thus, compared with an ethylene glycol antifreeze solution, an increase in viscosity under a low-temperature environment can be suppressed. Therefore, the same effect as the first embodiment can be obtained.

[0131] In addition, in this embodiment, the low temperature side heat transfer medium contains a nonionic rust inhibitor. By containing the low temperature side heat transfer medium, corrosion of the pipes through which the low temperature side heat transfer medium flows can be suppressed. Thus, the durability of the heat transfer system can be improved.

[0132] Furthermore, by using a nonionic rust inhibitor as the rust inhibitor, it is possible to ensure lower conductivity of the heat transfer medium than when using an ionic rust inhibitor as the rust inhibitor. As a result, it is not necessary to implement large-scale insulation measures on the heat transfer system.

[0133] In addition, in this embodiment, the amount of water contained in the low temperature side heat transfer medium is made to be greater than the amount of lower alcohol. Compared with ethylene glycol antifreeze, methanol aqueous solution and ethanol aqueous solution can maintain a lower freezing point and increase the proportion of water. Therefore, in the low temperature side heat transfer medium, by increasing the proportion of water with a larger heat capacity, the heat capacity of the low temperature side heat transfer medium can be increased, and the thermal conductivity can be further improved.

[0134] In addition, by increasing the proportion of water in the low temperature side heat transfer medium, the viscosity of the low temperature side heat transfer medium can be further reduced. In addition, by increasing the proportion of water in the low temperature side heat transfer medium, the cost of the low temperature side heat transfer medium can be reduced.

[0135] However, when the pipes through which the low-temperature side heat transfer medium flows are made of aluminum, the methanol and ethanol contained in the low-temperature side heat transfer medium may chemically react with the aluminum constituting the pipes to generate aluminum alcohol. As a result, the amount of lower alcohol contained in the low-temperature side heat transfer medium may decrease, thereby reducing the effect of suppressing the viscosity increase in a low-temperature environment. In other words, the freezing temperature may rise.

[0136] In contrast, by setting the amount of water contained in the low-temperature side heat transfer medium to be greater than the amount of lower alcohol as in the present embodiment, the proportion of water contained in the low-temperature side heat transfer medium is increased, and the generation of aluminum alcoholate can be suppressed. Thus, even when the pipe through which the low-temperature side heat transfer medium flows is composed of aluminum, the increase in viscosity in a low-temperature environment can be reliably suppressed. That is, the rise in the freezing temperature can be suppressed.

[0137] Furthermore, by setting the weight ratio of the lower alcohol to water in the low temperature side heat transfer medium to 35:65 to 50:50, the freezing point of the low temperature side heat transfer medium can be lower than the lowest temperature in the use environment. Therefore, freezing of the low temperature side heat transfer medium in a low temperature environment such as winter can be suppressed.

[0138] The present invention is not limited to the above-described embodiment, and various modifications, for example, as follows, are possible without departing from the gist of the present invention.

[0139] For example, in the first embodiment, methanol aqueous solution is used as the low-temperature side heat transfer medium of the low-temperature medium circuit 30, but the invention is not limited thereto, and methanol aqueous solution may be used as the high-temperature side heat transfer medium of the high-temperature medium circuit 20. In this case, the heat transfer medium can be shared in the high-temperature medium circuit 20 and the low-temperature medium circuit 30.

[0140] In the second embodiment, the methanol aqueous solution containing methanol, water, and a boiling point raising agent is used as the low-temperature side heat transfer medium of the low-temperature medium circuit 30, but the invention is not limited thereto, and the methanol aqueous solution may be used as the high-temperature side heat transfer medium of the high-temperature medium circuit 20. In this case, the heat transfer medium can be made common in the high-temperature medium circuit 20 and the low-temperature medium circuit 30.

[0141] In the third embodiment, an ethanol aqueous solution containing ethanol and water is used as the low-temperature side heat transfer medium of the low-temperature medium circuit 30, but the present invention is not limited thereto, and an ethanol aqueous solution may be used as the high-temperature side heat transfer medium of the high-temperature medium circuit 20. In this case, the heat transfer medium can be shared in the high-temperature medium circuit 20 and the low-temperature medium circuit 30.

[0142] In the fourth embodiment, a lower alcohol aqueous solution containing a lower alcohol, water, and a nonionic rust inhibitor is used as the low-temperature side heat transfer medium of the low-temperature medium circuit 30, but the invention is not limited thereto, and a lower alcohol aqueous solution may be used as the high-temperature side heat transfer medium of the high-temperature medium circuit 20. In this case, the heat transfer medium can be made common in the high-temperature medium circuit 20 and the low-temperature medium circuit 30.

[0143] In addition, in the above-mentioned embodiments, the third cooler 39 is described as an example of an oil cooler that cools the oil circulating in the oil circuit 40 by means of a low-temperature side heat transfer medium, but the present invention is not limited to this mode. For example, the third cooler 39 may be configured to cool the motor generator 35 by means of a low-temperature side heat transfer medium without using other heat transfer media (such as oil).

[0144] The present invention is described based on the embodiments, but it should be understood that the present invention is not limited to the embodiments and structures. The present invention also includes various modifications and variations within the scope of equality. In addition, various combinations and modes, and other combinations and modes that further include only one element, above or below it, are also included in the scope and thought range of the present invention.

[0145] (Overview of Embodiments of the Invention)

[0146] A heat transfer medium according to a first aspect of the present invention is used in a heat transfer system for transferring heat or cold of a refrigerant circulating in a refrigeration cycle device to an electric device, and contains a lower alcohol and water, wherein the lower alcohol is at least one of methanol and ethanol.

[0147] The heat transfer system of the second embodiment of the present invention comprises: a refrigeration cycle device, which circulates a refrigerant; a heat transfer medium circuit, which circulates a heat transfer medium; a cooling heat exchanger, which exchanges heat between the refrigerant and the heat transfer medium to cool the heat transfer medium; and an electrical device, which is arranged in the heat transfer medium circuit and absorbs heat from the heat transfer medium, and the heat transfer medium contains methanol and water.

[0148] According to the second aspect, by using a methanol aqueous solution containing methanol and water as the heat transfer medium, it is possible to suppress an increase in viscosity in a low-temperature environment.

[0149] The heat transfer system of the third embodiment of the present invention comprises: a refrigeration cycle device, which circulates a refrigerant; a heat transfer medium circuit, which circulates a heat transfer medium; a cooling heat exchanger, which exchanges heat between the refrigerant and the heat transfer medium to cool the heat transfer medium; and an electrical device, which is arranged in the heat transfer medium circuit and absorbs heat from the heat transfer medium, and the heat transfer medium is a methanol aqueous solution containing methanol, water and a boiling point raising agent.

[0150] According to the third aspect, by using a methanol aqueous solution containing methanol, water, and a boiling point increasing agent as the heat transfer medium, it is possible to suppress an increase in viscosity in a low temperature environment and also suppress boiling of the heat transfer medium.

[0151] A heat transfer system of a fourth embodiment of the present invention comprises: a refrigeration cycle device for circulating a refrigerant; a heat transfer medium circuit for circulating a heat transfer medium; a cooling heat exchanger for exchanging heat between the refrigerant and the heat transfer medium, thereby cooling the heat transfer medium; and an electrical device, which is arranged in the heat transfer medium circuit and causes the heat transfer medium to absorb heat, and the heat transfer medium is an ethanol aqueous solution containing ethanol and water.

[0152] According to the fourth aspect, by using an ethanol aqueous solution containing ethanol and water as the heat transfer medium, it is possible to suppress an increase in viscosity in a low-temperature environment and also suppress boiling of the heat transfer medium.

[0153] A fifth aspect of the heat transfer system of the present invention comprises: a refrigeration cycle device for circulating a refrigerant; a heat transfer medium circuit for circulating a heat transfer medium; a cooling heat exchanger for exchanging heat between the refrigerant and the heat transfer medium, thereby cooling the heat transfer medium; and an electrical device, which is arranged in the heat transfer medium circuit and absorbs heat from the heat transfer medium, wherein the heat transfer medium contains a lower alcohol such as at least one of methanol and ethanol, water, and a non-ionic rust inhibitor.

[0154] According to the fifth aspect, by using a lower alcohol aqueous solution containing at least one of methanol and ethanol, water, and a nonionic rust inhibitor as a heat transfer medium, the viscosity increase in a low temperature environment can be suppressed. In addition, by using a nonionic rust inhibitor as a rust inhibitor, the low conductivity of the heat transfer medium can be ensured.

Claims

1. A heat transfer medium, characterized in that: Used in heat transfer systems, which transfer the cold and heat of the refrigerant circulating in the refrigeration cycle device to electrical equipment, The heat transfer medium contains methanol, water and a boiling point raising agent to suppress the viscosity increase at -20°C to -35°C. The boiling point raising agent is a substance that is compatible with both water and methanol and has a higher boiling point than a mixture of water and methanol.

2. The heat transport medium according to claim 1, characterized in that The amount of water is greater than that of methanol.

3. The heat transport medium according to claim 1, characterized in that The weight ratio of methanol to water is 35:65 to 50:

50.

4. The heat transport medium according to claim 1, characterized in that The boiling point raising agent is at least one of alcohol, amine, ether and carboxylic acid.

5. The heat transport medium according to claim 1, characterized in that The proportion of the boiling point raising agent is less than 50%.

6. The heat transfer medium according to any one of claims 1 to 5, characterized in that Contains rust inhibitor.

7. The heat transport medium according to claim 1, characterized in that Contains non-ionic rust inhibitor.

8. The heat transport medium according to claim 7, characterized in that The nonionic rust inhibitor is Si ether and / or triazole.

9. A heat transfer system for transferring the heat and cold of a refrigerant circulating in a refrigeration cycle device to an electrical device, characterized in that: have: The refrigeration cycle device; a heat transport medium circuit for circulating a heat transport medium; and a cooling heat exchanger for exchanging heat between the refrigerant and the heat transfer medium to cool the heat transfer medium, The electrical device is arranged in the heat transfer medium circuit and absorbs heat from the heat transfer medium. As the heat transfer medium, the heat transfer medium according to any one of claims 1 to 8 is used.

10. The heat transport system according to claim 9, characterized in that The heat transport medium circuit is closed.

11. A heat transfer system for transferring the heat and cold of a refrigerant circulating in a refrigeration cycle device to an electrical device, characterized in that: have: The refrigeration cycle device; a heat transport medium circuit for circulating a heat transport medium; and a cooling heat exchanger for exchanging heat between the refrigerant and the heat transfer medium to cool the heat transfer medium, The electrical device is arranged in the heat transfer medium circuit and absorbs heat from the heat transfer medium. The heat transport system comprises: a high-temperature side heat transfer medium circuit, wherein the high-temperature side heat transfer medium circuit circulates a high-temperature side heat transfer medium having a higher temperature than the heat transfer medium; and a heating heat exchanger for exchanging heat between the refrigerant and the high-temperature-side heat transfer medium to heat the high-temperature-side heat transfer medium, As the heat transfer medium and the high temperature side heat transfer medium, the heat transfer medium according to any one of claims 1 to 8 is used.

12. The heat transport system according to claim 11, characterized in that The high-temperature side heat transfer medium circuit is sealed.

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