JP2011021789A - Evaporative cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaporative cooling device separating a mixed refrigerant into a mixed refrigerant having a high ratio of a high boiling point refrigerant and a mixed refrigerant having a high ratio of a low boiling point refrigerant, even when the mixed refrigerant is forcedly circulated. <P>SOLUTION: The evaporative cooling device 10 is equipped with: a heat exchanger 11; a first tank 12; and a second tank 13. The first tank 12 is equipped with a first condensation part 21a, and a second tank 13 with a second condensation part 21b. The first condensation part 21a is adjusted to be a boiling point or higher and a condensation point or lower of a two-component refrigerant by a heater H. The second condensation part 21b is adjusted to be the boiling point or lower of the two-component refrigerant by a radiator 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a boiling cooling device.

  As the refrigerant used in the boiling cooling device, water having large latent heat and excellent cooling performance is used. However, since water freezes in an environment where the temperature is below freezing, water cannot be used in a boiling cooling device that is assumed to be used in an environment where the temperature is below freezing. Therefore, by mixing ethyl alcohol with water to make a two-component refrigerant (mixed refrigerant) and increasing the ratio of ethyl alcohol to lower the freezing point of the two-component refrigerant, water can be used as a refrigerant even in environments where the temperature is below freezing point. The boiling cooling system that had been used is made available. However, since ethyl alcohol has a small latent heat, if the ratio of ethyl alcohol in the two-component refrigerant is increased, it becomes smaller than the amount of latent heat when only water is used as the refrigerant, and the boiling cooling performance is lowered.

  Thus, for example, Patent Document 1 discloses a technique in which boiling cooling performance is not lowered while using a two-component refrigerant. In the refrigerator of Patent Document 1, when the refrigerator is operated, in the high-temperature side secondary refrigerant circulation circuit, in the high-temperature side evaporator (heat exchanger), the low-boiling point refrigerant boils and evaporates before the high-boiling point refrigerant, The evaporated low boiling point refrigerant rises toward the high temperature side condenser (condensing part) by natural circulation, and is condensed and liquefied by the high temperature side condenser. Furthermore, the liquefied low boiling point refrigerant tends to return from the high temperature side condenser to the high temperature side evaporator by natural circulation, but is stored in the isolation tank (storage part) through the communication port. As the amount of low-boiling refrigerant stored in the isolation tank increases, the two-component refrigerant in the high-temperature side secondary refrigerant circulation circuit has a high ratio of high-boiling refrigerant and excellent cooling efficiency. Thereby, the amount of latent heat released by the high temperature side evaporator is increased, and the boiling cooling performance is improved. On the other hand, after the operation of the refrigerator is stopped, the low-boiling point refrigerant stored in the isolation tank is mixed with the high-boiling point refrigerant to obtain a two-component refrigerant with an increased ratio of the low-boiling point refrigerant. However, it is possible to make the two-component refrigerant difficult to freeze.

JP 2006-349233 A

  However, in the refrigerator of Patent Document 1, in the high temperature side secondary refrigerant circulation circuit, the two-component refrigerant undergoes a phase change and naturally circulates in the high temperature side secondary refrigerant circulation circuit. For this reason, the circulation speed of the two-component refrigerant in the high-temperature side secondary refrigerant circulation circuit is slow, and the cooling efficiency is low. In order to improve the cooling efficiency, it is conceivable to forcibly circulate the two-component refrigerant in the high temperature side secondary refrigerant circulation circuit.

  When the two-component refrigerant is forcibly circulated in the high-temperature side secondary refrigerant circulation circuit, a part of the two-component refrigerant supplied to the high-temperature side evaporator passes through the high-temperature side evaporator without being boiled. . Then, the two-component refrigerant that has passed through the high-temperature side evaporator in the liquid state flows into the isolation tank in which the low-boiling point refrigerant is stored, and the high-temperature side evaporator remains in the liquid state with the low-boiling point refrigerant stored in the isolation tank. The two-component refrigerant that has passed through is mixed. As a result, while the low boiling point refrigerant is stored in the isolation tank, the two component refrigerant in the high temperature side secondary refrigerant circulation circuit cannot be changed to a two component refrigerant having a high ratio of the high boiling point refrigerant. It becomes impossible to separate the two-component refrigerant having a high ratio and the two-component refrigerant having a high ratio of the low boiling point refrigerant.

  An object of the present invention is to provide a boiling cooling device capable of separating a mixed refrigerant having a high ratio of high boiling point refrigerant and a mixed refrigerant having a high ratio of low boiling point refrigerant even if the mixed refrigerant is forcedly circulated. is there.

  In order to achieve the above object, the invention according to claim 1 is characterized in that a mixed refrigerant in which at least two kinds of a high-boiling point refrigerant and a low-boiling point refrigerant are mixed is forcedly circulated through a circulation channel by a refrigerant transfer means, A boiling cooling device in which heat is exchanged between the mixed refrigerant and an object to be cooled in a heat exchanger provided on a circulation channel, wherein the first storage unit is disposed on the circulation channel, and the first A first condensing unit disposed in the storing unit, a first temperature adjusting unit that adjusts the temperature of the first condensing unit to a boiling point of the mixed refrigerant and lower than a condensing point, and the first storing unit And adjusting the temperature of the second condensing part connected to the steam passage, the second condensing part arranged in the second accumulating part, and the temperature of the second condensing part to be lower than the temperature of the first condensing part. Stored in the second temperature adjustment unit and the second storage unit. The mixed refrigerant is summarized as further comprising a, a recirculation passage that recirculates into the circulation flow path.

  According to this invention, the temperature of the 1st condensation part arrange | positioned at a 1st storage part is more than the boiling point of a mixed refrigerant by the 1st temperature adjustment part, and is adjusted below the condensation point. For this reason, the mixed refrigerant that has passed through the heat exchanger and has flowed into the first storage section is condensed by the first condensed section and the liquid mixed refrigerant containing a large amount of high-boiling refrigerant condensed and liquefied by the first condensing section. It is separated into a gaseous mixed refrigerant containing a large amount of low-boiling-point refrigerant. And the mixed refrigerant | coolant which contains many high boiling-point refrigerant | coolants is stored in a 1st storage part. Moreover, the temperature of the 2nd condensation part arrange | positioned at a 2nd storage part is adjusted to the temperature lower than the temperature of a 1st condensation part by the 2nd temperature adjustment part. For this reason, the gaseous mixed refrigerant | coolant which contains many low boiling-point refrigerant | coolants which flowed into the 2nd storage part from the 1st storage part is condensed and liquefied by the 2nd condensation part, and is stored by the 2nd storage part. Therefore, while the mixed refrigerant with a high ratio of a high boiling point refrigerant is stored in the 1st storage part, the mixed refrigerant with a high ratio of a low boiling point refrigerant is stored in the 2nd storage part. Therefore, even if the mixed refrigerant is forcibly circulated through the circulation channel using the refrigerant transfer means, the mixed refrigerant can be separated into a mixed refrigerant having a high ratio of high boiling point refrigerant and a mixed refrigerant having a high ratio of low boiling point refrigerant. it can.

  According to a second aspect of the present invention, in the first aspect of the present invention, a first control valve is provided downstream of the first storage section on the circulation flow path and upstream of the heat exchanger. And a second control valve is disposed on the reflux path, and a controller for controlling opening and closing of the first control valve and the second control valve is further provided, and the operation of the boiling cooling device At the time, at least the first control valve is opened and the second control valve is closed by the control unit, and before the boiling cooling device is stopped, at least the second control valve is The gist is that the control to be opened is performed by the control unit.

  According to the present invention, during the operation of the boiling cooling device, while the mixed refrigerant is forcedly circulated, the mixed refrigerant having a high ratio of the high boiling point refrigerant is supplied to the first storage part and the mixed refrigerant having the high ratio of the low boiling point refrigerant is set. It isolate | separates into a 2nd storage part, respectively. And the mixed refrigerant | coolant with a high ratio of the high boiling point refrigerant | coolant isolate | separated by the 1st storage part can be circulated to a circulation flow path. Therefore, the mixed refrigerant having high latent heat can be supplied into the heat exchanger, and the cooling performance can be improved as compared with the boiling cooling by the mixed refrigerant having a high ratio of the low boiling point refrigerant. In addition, before the boiling cooling device is stopped, the mixed refrigerant having a high ratio of the low boiling point refrigerant stored in the second storage unit is all returned to the circulation channel via the reflux channel. Thereby, since the composition ratio of the low boiling point refrigerant in the mixed refrigerant flowing in the circulation channel becomes the same composition ratio as the state before the operation, it can be a mixed refrigerant having a high ratio of the low boiling point refrigerant. It is possible to prevent the mixed refrigerant from freezing.

  According to a third aspect of the present invention, there is provided the control according to the second aspect, wherein the first control valve is closed and the second control valve is opened before the boiling cooling device is stopped. The gist is to be performed by the control unit.

  According to the present invention, the mixed refrigerant having a high ratio of the low boiling point refrigerant stored in the second storage unit is recirculated to the circulation channel via the reflux path, and the low boiling point refrigerant stored in the second storage unit is recirculated. A mixed refrigerant having a high ratio can be caused to flow into the first storage part, and can be mixed with a mixed refrigerant having a high ratio of the high boiling point refrigerant stored in the first storage part. Thereby, since the composition ratio of the low boiling point refrigerant in the mixed refrigerant stored in the first storage unit becomes the same composition ratio as that before the operation, the mixed refrigerant having a high ratio of the low boiling point refrigerant can be obtained.

  According to a fourth aspect of the invention, in the invention of the second or third aspect, when the boiling cooling device is in operation, the first control valve and the second control valve are opened at the start of the operation. When the composition ratio of the low-boiling-point refrigerant with respect to the entire refrigerant mixture stored in the first storage section reaches a predetermined composition ratio, the control section performs control for closing the second control valve. Is the gist.

  According to this invention, when the composition ratio of the low-boiling-point refrigerant with respect to the entire mixed refrigerant stored in the first storage unit reaches a predetermined composition ratio, the control unit closes the second control valve, and the first storage unit It is possible to supply only the mixed refrigerant having a high ratio of the high boiling point refrigerant stored in the heat exchanger to the heat exchanger via the circulation line. Here, the “predetermined composition ratio” is a composition ratio of the low boiling point refrigerant to the whole mixed refrigerant that can be determined that the mixed refrigerant stored in the first storage unit is a two-component refrigerant having a high ratio of the high boiling point refrigerant. Say.

The invention according to claim 5 is the invention according to any one of claims 1 to 4,
The gist of the second temperature adjusting unit is to adjust the temperature of the second condensing unit below the boiling point of the mixed refrigerant.

  According to the present invention, the gaseous mixed refrigerant containing a large amount of the low-boiling-point refrigerant that has flowed into the second reservoir from the first reservoir is condensed and liquefied by the second condenser, and is stored in the second reservoir. . Therefore, it can suppress that the gaseous mixed refrigerant | coolant remains in the 2nd storage part, without being condensed by the 2nd condensation part.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the first temperature adjustment unit uses heat received by heat exchange with the heat exchanger. This is the gist.

  According to the present invention, for example, when a heater is used as the first temperature adjustment unit, it is not necessary to secure electric power for operating the heater. Therefore, electric power is required to operate the first temperature adjustment unit. Compared with the required configuration, the entire boiling cooling device can be saved.

  According to this invention, even if the mixed refrigerant is forcibly circulated, it can be separated into a mixed refrigerant having a high ratio of high boiling point refrigerant and a mixed refrigerant having a high ratio of low boiling point refrigerant.

The schematic block diagram of the boiling cooling device in this embodiment. The characteristic view which shows the gas-liquid equilibrium relationship of a two-component refrigerant | coolant. The schematic block diagram of the boiling cooling device in another embodiment. The schematic block diagram of the boiling cooling device in another embodiment.

  Hereinafter, an embodiment in which the boiling cooling device of the present invention is embodied in an EGR gas cooling device (EGR cooler) provided in an exhaust gas recirculation (EGR) of a vehicle according to FIGS. 1 and 2. explain. In the boiling cooling device 10, a two-component refrigerant is circulated and used as a mixed refrigerant, and heat is exchanged between the EGR gas as the cooled object and the two-component refrigerant in the heat exchanger 11, and a part of the two-component refrigerant is boiled. To cool the EGR gas. Although not shown in FIG. 1, an EGR passage through which EGR gas flows passes through the heat exchanger 11 of the boiling cooling device 10. The two-component refrigerant in the present embodiment is a mixture of water as a high boiling point refrigerant and ethyl alcohol as a low boiling point refrigerant.

  As shown in FIG. 1, the heat exchanger 11 of the boiling cooling device 10 is connected to the first tank 12 via a first pipe 14, and the first tank 12 has a second pipe 15 as a steam passage. The second tank 13 is connected to the second tank 13. In addition, a third pipe 16 is provided so as to connect the first tank 12 and the heat exchanger 11, and a fourth as a reflux path so as to connect the second tank 13 and the third pipe 16. A pipe 17 is provided. The third pipe 16 is provided with a pump P1 as a refrigerant transfer means. The pump P1 is connected to a drive source (not shown) provided in the vehicle.

  And in the boiling cooling device 10 in this embodiment, when a drive source is driven with driving | running | working of a vehicle and the pump P1 drives, a two-component refrigerant | coolant is heat-exchanged by the pump P1, the 1st piping 14, 1st. The tank 12 and the third pipe 16 are forcibly circulated. In other words, in the present embodiment, the heat exchanger 11, the first pipe 14, the first tank 12, and the third pipe 16 constitute a circulation channel through which the two-component refrigerant is forcedly circulated.

  Further, in the third pipe 16, a first control valve 18 is disposed in a part closer to the first tank 12 than the connection part S between the third pipe 16 and the fourth pipe 17. Further, a second control valve 19 is disposed in the fourth pipe 17. Each of the control valves 18 and 19 is driven to open and close in response to a command from an ECU (electronic control unit) 31 as a control unit.

  The boiling cooling device 10 is provided with a circulation line 21 for circulating a refrigerant different from the two-component refrigerant in a direction indicated by an arrow R shown in FIG. A part of the circulation pipe 21 passes through the radiator 20 mounted on the vehicle, and the refrigerant circulating through the circulation pipe 21 is cooled by the radiator 20. A pump P <b> 2 for forcibly circulating the refrigerant in the circulation line 21 is disposed on the downstream side of the radiator 20 in the circulation line 21. The pump P2 is connected to a drive source (not shown) provided in the vehicle.

  In the circulation pipe 21, a part of the upstream side of the radiator 20 in the refrigerant flow direction is drawn into the first tank 12, and the two-component refrigerant is condensed in the first tank 12 by the drawn part. A first condensing part 21a is formed. Further, in the circulation pipe 21, a part of the downstream side of the pump P <b> 2 in the refrigerant flow direction is drawn into the second tank 13, and the two-component refrigerant in the second tank 13 is drawn by this drawn part. The 2nd condensation part 21b which condenses is formed. Further, in the circulation pipe 21, a heater H is provided on the downstream side of the second condensing part 21b in the refrigerant flow direction and on the upstream side of the first condensing part 21a.

  The heater H operates by being supplied with electric power from a power supply source (not shown), and the heater H has a temperature of the refrigerant flowing through the first condensing unit 21a equal to or higher than the boiling point of the two-component refrigerant. The heater H functions as a first temperature adjusting unit. Note that power supply control and temperature adjustment control from the power supply source to the heater H are performed by the ECU 31.

  When the refrigerant circulating in the circulation line 21 passes through the radiator 20, the refrigerant is cooled so as to have a temperature equal to or lower than the boiling point of the two-component refrigerant, which is lower than the temperature of the refrigerant flowing in the first condenser 21 a. Thus, the temperature of the refrigerant flowing in the second condensing unit 21b is adjusted so as to be equal to or lower than the boiling point of the two-component refrigerant, and the radiator 20 functions as a second temperature adjusting unit.

  Here, in the case of a two-component refrigerant in which water and ethyl alcohol are mixed, a vapor-liquid equilibrium relationship as shown in FIG. 2 is theoretically obtained when the pressure in phase change is constant. In FIG. 2, the horizontal axis represents the composition ratio X of ethyl alcohol with respect to the entire two-component refrigerant, and the vertical axis represents temperature. That is, in FIG. 2, the composition ratio X = 0 represents the composition characteristic of only water, and the composition ratio X = 1.0 represents the composition characteristic of only ethyl alcohol. Further, when the initial composition ratio of the two-component refrigerant is determined, as shown in FIG. 2, the liquidus line L1 and the gas phase line L2 for each temperature and pressure are determined, and the region below the liquidus line L1 is excessive. In the cooling state, the region above the gas phase line L2 is determined as an overheated state, and the region surrounded by the liquid phase line L1 and the gas phase line L2 is determined as a gas-liquid two-phase state. That is, the temperature on the liquidus line L1 is the boiling point of the two-component refrigerant corresponding to the composition ratio X of ethyl alcohol. Further, the temperature on the gas phase line L2 becomes a condensation point of the two-component refrigerant corresponding to the composition ratio X of ethyl alcohol.

  In FIG. 2, for example, a case where a two-component refrigerant having an initial composition ratio of ethyl alcohol with a composition ratio X = X1 is condensed at a temperature T1 that is equal to or higher than the boiling point of the two-component refrigerant and equal to or lower than the condensation point. The two-component refrigerant is a liquid two-component refrigerant having a composition ratio X = X2 containing a lot of water on the liquidus line L1, and a gas two-component refrigerant containing a composition ratio X = X3 containing a lot of ethyl alcohol on the gas phase line L2. Separated into refrigerant. Among the gas-liquid two-phase two-component refrigerant, the liquid two-component refrigerant has a high water concentration, and the gas two-component refrigerant has a high ethyl alcohol concentration.

  Since the boiling cooling device 10 of the present embodiment uses the above-described vapor-liquid equilibrium relationship of the two-component refrigerant, the temperature of the refrigerant flowing in the first condensing unit 21a is equal to or higher than the boiling point of the two-component refrigerant by the heater H. And it is adjusted to be below the condensation point.

Next, the operation in the boiling cooling device 10 having the above configuration will be described.
First, in a state where the vehicle is stopped, all of the two-component refrigerant is stored in the first tank 12. When the operation of the vehicle is started, the pump P2 is driven and the refrigerant circulates through the circulation line 21. And while the temperature of the refrigerant | coolant which flows through the inside of the 1st condensation part 21a is more than the boiling point of a two-component refrigerant | coolant by the heater H, and is adjusted below a condensation point, the temperature of the refrigerant | coolant which flows through the inside of the 2nd condensation part 21b is It is adjusted below the boiling point of the two-component refrigerant by the radiator 20. Further, the ECU 31 opens the first control valve 18 and the second control valve 19. At this time, the ECU 31 controls the first control valve 18 and the second control valve 19 so that the opening degree of the first control valve 18 is larger than the opening degree of the second control valve 19. Further, the drive source is driven as the vehicle is driven, and the pump P1 is driven by the power from the drive source, and the two-component refrigerant stored in the first tank 12 is driven by the pump P1. 3 is supplied to the heat exchanger 11 through the three pipes 16.

  In the heat exchanger 11, heat exchange is performed between the EGR gas flowing into the heat exchanger 11 from the EGR passage and the two-component refrigerant, and the EGR gas is cooled by latent heat as the two-component refrigerant boils. As a result of heat exchange between the EGR gas and the two-component refrigerant, the two-component refrigerant is heated and boiled to become a vaporized two-component refrigerant, and a two-component refrigerant that passes through the heat exchanger 11 in a liquid state. It becomes a gas-liquid two-phase state where these two types are mixed. The two-component refrigerant in the gas-liquid two-phase state passes through the heat exchanger 11 and then flows into the first tank 12 through the first pipe 14.

  The two-component refrigerant that has passed through the heat exchanger 11 in a liquid state is stored in the first tank 12 as it is, and the two-component refrigerant that has boiled in the heat exchanger 11 to become a gas is stored in the first tank 12. In contact with the first condensing part 21a. Here, the temperature of the refrigerant flowing in the first condensing part 21a is not less than the boiling point of the two-component refrigerant and is adjusted by the heater H below the condensation point. Therefore, the two-component refrigerant that has boiled in the heat exchanger 11 and turned into gas contains a lot of water condensed and liquefied by the first condensing unit 21a from the gas-liquid equilibrium relationship of the two-component refrigerant shown in FIG. It is separated into a liquid two-component refrigerant and a gas two-component refrigerant that contains a large amount of ethyl alcohol that has not been condensed by the first condensing part 21a.

  The liquid two-component refrigerant containing a large amount of water is stored in the first tank 12 as it is. Therefore, the first tank 12 stores the two-component refrigerant that has passed through the heat exchanger 11 in a liquid state and the liquid two-component refrigerant that contains a large amount of water condensed and liquefied by the first condensing unit 21a. It becomes a state.

  On the other hand, the gaseous two-component refrigerant that contains a large amount of ethyl alcohol that has not been condensed by the first condensing unit 21 a flows into the second tank 13 through the second pipe 15 without being stored in the first tank 12. And the gaseous two-component refrigerant | coolant which contains many ethyl alcohol which flowed in in the 2nd tank 13 contacts the 2nd condensing part 21b in the 2nd tank 13. FIG. Here, since the refrigerant flowing in the second condensing part 21b is cooled to a temperature below the boiling point of the two-component refrigerant by the radiator 20, the gaseous two-component refrigerant containing a large amount of ethyl alcohol flowing into the second tank 13 is The second condensing unit 21 b condenses and liquefies all of the water and is stored in the second tank 13.

  Therefore, the two-component refrigerant having a high water ratio is stored in the first tank 12, and the two-component refrigerant having a high ethyl alcohol ratio is stored in the second tank 13, and the two-component refrigerant is forcibly circulated. Alternatively, it can be separated into a two-component refrigerant having a high water ratio and a two-component refrigerant having a high ethyl alcohol ratio.

  When the composition ratio of ethyl alcohol to the entire two-component refrigerant stored in the first tank 12 reaches a predetermined composition ratio (for example, composition ratio X = 5% or less), the ECU 31 opens the first control valve 18. While maintaining the state, the second control valve 19 is closed. As a result, only the two-component refrigerant having a high ratio of water stored in the first tank 12 can be supplied to the heat exchanger 11, and the two-component refrigerant having high latent heat is supplied into the heat exchanger 11. be able to. Here, the “predetermined composition ratio” is a composition ratio of ethyl alcohol to the entire two-component refrigerant that can be determined that the two-component refrigerant stored in the first tank 12 is a two-component refrigerant having a high ratio of water. Say.

  When stopping the vehicle, the ECU 31 closes the first control valve 18 and opens the second control valve 19. Then, the two-component refrigerant having a high ratio of ethyl alcohol stored in the second tank 13 passes through the fourth pipe 17, the third pipe 16, the heat exchanger 11, and the first pipe 14. All are refluxed in. As a result, the composition ratio of ethyl alcohol in the two-component refrigerant stored in the first tank 12 is the same as the composition ratio before the vehicle operation is started, so the two-component refrigerant having a high ethyl alcohol ratio. It is possible to prevent the two-component refrigerant from freezing in a cold region.

In the above embodiment, the following effects can be obtained.
(1) The 1st condensation part 21a is provided in the 1st tank 12 which constitutes the circulation channel of boiling cooling device 10, and the 2nd condensation part 21b is provided in the 2nd tank 13. The first condensing unit 21 a is adjusted to be equal to or higher than the boiling point of the two-component refrigerant by the heater H and below the condensing point, and the second condensing unit 21 b is adjusted to be equal to or lower than the boiling point of the two-component refrigerant by the radiator 20. Therefore, the two-component refrigerant that has flowed into the first tank 12 is a liquid two-component refrigerant that contains a large amount of water condensed and liquefied by the first condensing unit 21a, and ethyl that has not been condensed by the first condensing unit 21a. Separated into gaseous two-component refrigerant rich in alcohol. Further, the gaseous two-component refrigerant containing a large amount of ethyl alcohol that has flowed into the second tank 13 from the first tank 12 is all condensed and liquefied by the second condensing part 21 b and stored in the second tank 13. . Therefore, in the circulation direction of the two-component refrigerant in the circulation channel, the second tank 13 having the second condensing part 21b is provided downstream of the first tank 12 in which the first condensing part 21a is arranged. While the two-component refrigerant is forcibly circulated through the flow path, the two-component refrigerant having a high water ratio can be stored in the first tank 12 and the two-component refrigerant having a high ethyl alcohol ratio can be stored in the second tank 13.

  (2) A first control valve 18 is disposed on the refrigerant flow path on the downstream side of the first tank 12 and on the upstream side of the heat exchanger 11, and the fourth pipe 17 has a second control. A valve 19 is provided. When the composition ratio of ethyl alcohol with respect to the entire two-component refrigerant stored in the first tank 12 reaches a predetermined composition ratio, the first control valve 18 is open and the second control valve 19 is When the valve is closed, only the two-component refrigerant having a high ratio of water stored in the first tank 12 can be supplied to the heat exchanger 11. Therefore, a two-component refrigerant having a high latent heat can be supplied into the heat exchanger 11, and the cooling performance can be improved as compared with boiling cooling using a two-component refrigerant having a high ethyl alcohol ratio.

  (3) When stopping the vehicle, the first control valve 18 is closed and the second control valve 19 is opened, so that the two-component refrigerant having a high ratio of ethyl alcohol stored in the second tank 13 is supplied. All are recirculated into the first tank 12 through the fourth pipe 17, the third pipe 16, the heat exchanger 11, and the first pipe 14. As a result, the composition ratio of ethyl alcohol in the two-component refrigerant stored in the first tank 12 is the same as the composition ratio before the vehicle operation is started, so the two-component refrigerant having a high ethyl alcohol ratio. It is possible to prevent the two-component refrigerant from freezing in a cold region.

  (4) The second condensing part 21b is adjusted by the radiator 20 below the boiling point of the two-component refrigerant. Therefore, the gaseous two-component refrigerant containing a large amount of ethyl alcohol flowing into the second tank 13 from the first tank 12 is all condensed and liquefied by the second condensing part 21 b and stored in the second tank 13. Therefore, the gaseous two-component refrigerant containing a large amount of ethyl alcohol flowing into the second tank 13 from the first tank 12 is prevented from remaining in the second tank 13 without being condensed by the second condensing unit 21b. Can do.

  (5) The boiling cooling device 10 includes a first tank 12 provided with a first condensing part 21a and a second tank 13 provided with a second condensing part 21b. Therefore, even if the temperature suddenly rises in the heat exchanger 11 and the two-component refrigerant having a high water ratio and the two-component refrigerant having a high ethyl alcohol ratio boil synchronously, the first tank 12 can store a two-component refrigerant having a high water ratio, and the second tank 13 can store a two-component refrigerant having a high ethyl alcohol ratio.

  (6) The boiling cooling device 10 is provided with a circulation line 21, and the circulation line 21 passes through the first tank 12 and the second tank 13, respectively. Accordingly, separate circulation pipes are provided in the first tank 12 and the second tank 13, respectively, and a part of the circulation pipe corresponding to the first tank 12 is used as the first condensing part, and the circulation pipe corresponding to the second tank. Compared with the case where a part of the path is the second condensing part, the entire configuration of the boiling cooling device 10 can be simplified.

  (7) Since the radiator 20 mounted on the vehicle is used as the second temperature adjusting unit, it is possible to reduce the size of the vehicle itself as compared with a case where another device is mounted as the second temperature adjusting unit. it can.

In addition, you may change the said embodiment as follows.
In the embodiment, as shown in FIG. 3, the refrigerant flow direction in the circulation pipe 21 may be reversed, and the first temperature adjustment unit may be a heat receiving unit 41 provided on the upstream side of the first tank 12. The heat receiving part 41 directly receives the heat of the EGR gas flowing into the heat exchanger 11 from the EGR passage. Note that the circulation pipe 21 is partially pulled into the second tank 13 after passing through the radiator 20. In this case, the flow rate of the refrigerant flowing in the circulation pipe 21 is adjusted by the pump P2 in accordance with the amount of heat from the EGR gas received by the heat receiving unit 41, so that the temperature of the refrigerant flowing in the first condensing unit 21a is two-component The temperature is adjusted to be equal to or higher than the boiling point of the refrigerant and equal to or lower than the condensation point. According to this, since it is not necessary to secure the electric power for operating the heater H, the entire boiling cooling device 10 can be energy-saving compared with the case where the heater H is provided in the circulation line 21.

  In the embodiment, the first control valve 18 and the second control valve 19 may be omitted. For example, as shown in FIG. 4, the first tank 12 is joined to the lower surface of the second tank 13 so as to be positioned below the second tank 13 in the direction of gravity (the direction of arrow G shown in FIG. 4). . One end side of the third pipe 16 is drawn into the first tank 12 and the other end is connected to the heat exchanger 11. Further, the pump P <b> 1 provided in the third pipe 16 is disposed in the first tank 12. The first pipe 14 connects the heat exchanger 11 and the first tank 12. Therefore, the heat exchanger 11, the first pipe 14, the first tank 12, and the third pipe 16 constitute a circulation passage through which the two-component refrigerant is forcedly circulated.

  A steam passage formed on the joint surface between the first tank 12 and the second tank 13 so as to allow the inside of the first tank 12 and the inside of the second tank 13 to communicate with each other and protrude toward the inside of the second tank 13. 15a is provided. The length of the vapor passage 15a in the protruding direction is higher in the opening surface of the vapor passage 15a that opens in the second tank 13 than in the storage surface of the liquid two-component refrigerant stored in the second tank 13. Is set to Further, the joint surface between the first tank 12 and the second tank 13 is formed so as to allow the inside of the first tank 12 and the inside of the second tank 13 to communicate with each other and protrude toward the inside of the first tank 12. A reflux path 17a is provided. The diameter of the reflux path 17a is much smaller than the diameter of the steam path 15a.

  The circulation conduit 21 is drawn so as to pass through the first tank 12 after passing through the heater H, and a first condensing portion 21a is formed by the drawn portion. The circulation line 21 is drawn so as to pass through the second tank 13 after passing through the radiator 20, and a second condensing part 21 b is formed by the drawn part.

  When the pump P1 is driven, the two-component refrigerant stored in the first tank 12 is forced to circulate through the circulation flow path via the tip of the third pipe 16, and at the first condensing unit 21a. The gaseous two-component refrigerant containing a large amount of ethyl alcohol that has not been condensed flows into the second tank 13 through the vapor passage 15a. Here, since the diameter of the reflux path 17a is much smaller than the diameter of the steam path 15a, the two-component refrigerant that has been completely condensed and liquefied by the second condensing part 21b passes through the first reflux path 17a. The recirculation of the tank 12 at a stretch is suppressed. Therefore, in the boiling cooling device 10 in which the first control valve 18 and the second control valve 19 are omitted, even if the two-component refrigerant is forcibly circulated, the two-component refrigerant having a high water ratio is supplied to the first tank 12. Two-component refrigerant having a high ratio of ethyl alcohol can be stored in the two tanks 13.

  In the embodiment, when the operation of the vehicle is started, the ECU 31 controls the first control valve 18 and the second control so that the opening degree of the first control valve 18 is larger than the opening degree of the second control valve 19. Although the opening degree of the valve 19 is controlled, the present invention is not limited to this. For example, when the operation of the vehicle is started, the ECU 31 may control to open the first control valve 18 and close the second control valve 19. According to this, since it is not necessary to adjust the opening degree of the first control valve 18 and the second control valve 19, it is possible to use a simplified opening / closing valve having a structure capable of only opening and closing that cannot be adjusted. .

  In the embodiment, when the vehicle is stopped, the first control valve 18 is closed and the second control valve 19 is opened, but the present invention is not limited to this. For example, when the vehicle is stopped, the first control valve 18 and the second control valve 19 are once opened, and the two-component refrigerant in the first tank 12 and the two-component refrigerant in the second tank 13 are The first control valve 18 may be closed after mixing in the circulation flow path so that all the two-component refrigerants are recirculated into the first tank 12.

  In the embodiment, the temperature of the second condensing unit 21b is adjusted to be equal to or lower than the boiling point of the two-component refrigerant by the radiator 20, but not limited to this, the temperature of the second condensing unit 21b is the first condensing unit. You may make it adjust to temperature lower than the temperature of 21a. Even in this case, the gaseous two-component refrigerant containing a large amount of ethyl alcohol flowing into the second tank 13 from the first tank 12 is condensed and liquefied by the second condensing unit 21 b and stored in the second tank 13. Is done. However, in order to condense and liquefy the gaseous two-component refrigerant containing a large amount of ethyl alcohol flowing into the second tank 13 from the first tank 12, the temperature of the second condensing unit 21b is adjusted to be equal to or lower than the boiling point of the two-component refrigerant. Is preferred.

  In the embodiment, the circulation conduit 21 passes through the first tank 12 and the second tank 13, respectively, but is not limited thereto. For example, the first tank 12 and the second tank 13 are provided with separate circulation lines, respectively, and a part of the circulation line corresponding to the first tank 12 is used as the first condensing unit, and the circulation corresponding to the second tank 13 is performed. It is good also considering a part of pipe line as a 2nd condensation part. In this case, the first temperature adjustment unit is provided in the circulation line corresponding to the first tank 12, and the second temperature adjustment unit is provided in the circulation line corresponding to the second tank 13.

  In the embodiment, the first condensing unit 21a and the second condensing unit 21b are provided by drawing a part of the circulation conduit 21 into the first tank 12 and the second tank 13, respectively. Not exclusively. For example, while providing the 1st condensing part which can cool the outer wall of the 1st tank 12, you may make it provide the 2nd condensing part which can cool the outer wall of the 2nd tank 13. In such a case, the first condensing unit and the second condensing unit are not limited to liquid cooling but may be air cooling.

  In the embodiment, the two-component refrigerant stored in the second tank 13 is returned to the third pipe 16 via the fourth pipe 17, but is not limited thereto. For example, the two-component refrigerant stored in the second tank 13 may be directly flowed into the first tank 12 or directly flowed into the heat exchanger 11.

  In the embodiment, the first control valve 18 may be omitted. In this case, for example, when the first tank 12 is disposed below the heat exchanger 11 in the direction of gravity, and when the boiling cooling device 10 (pump P1) is stopped, the two-component refrigerant flowing through the circulation channel is changed by gravity. The two-component refrigerant is stored in the first tank 12 by falling naturally toward the one tank 12.

  In the embodiment, the two-component refrigerant is a mixture of water as a high-boiling point refrigerant and ethyl alcohol as a low-boiling point refrigerant, but is not limited to this. If it is a component refrigerant | coolant, the kind of a high boiling point refrigerant | coolant and a low boiling point refrigerant | coolant will not be specifically limited.

  In the embodiment, a two-component refrigerant consisting of two types of high-boiling point refrigerant and low-boiling point refrigerant is used as the mixed refrigerant. However, the present invention is not limited to this, and at least two types of high-boiling point refrigerant and low-boiling point refrigerant are mixed. In addition, a mixed refrigerant in which several kinds of refrigerants are mixed may be used.

  In the embodiment, the boiling cooling device 10 is embodied as an EGR gas cooling device (EGR cooler). However, the boiling cooling device 10 is not limited thereto, and the boiling cooling device 10 is, for example, a cooling device for an in-vehicle device, a refrigerator, a freezer, or the like. It may be embodied in.

In the embodiment, the object to be cooled is EGR gas. However, the present invention is not limited to this, and the object to be cooled may be gas, liquid, or solid other than EGR gas.
Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.

(A) The high-boiling point refrigerant is water, and the low-boiling point refrigerant is ethyl alcohol. The boiling cooling device according to any one of claims 1 to 6, wherein the low-boiling point refrigerant is ethyl alcohol.
(B) The boiling cooling device according to any one of claims 1 to 6, and the technical idea (a), which is mounted on a vehicle.

  H: Heater as first temperature adjustment unit, P1: Pump as refrigerant transfer means, 10: Boiling cooler, 11 ... Heat exchanger, 12 ... First tank as first storage unit, 13 ... Second storage unit As a second tank, 14 ... a first pipe constituting a circulation passage, 15 ... a second pipe as a steam passage, 15a ... a steam passage, 16 ... a third pipe constituting a circulation passage, 17 ... 4th piping as a reflux path, 17a ... reflux path, 18 ... 1st control valve, 19 ... 2nd control valve, 20 ... Radiator as 2nd temperature control part, 21a ... 1st condensation part, 21b ... 2nd Condensing part, 31 ... ECU (electronic control unit) as a control part, 41 ... Heat receiving part.

Claims (6)

A mixed refrigerant in which at least two kinds of a high-boiling point refrigerant and a low-boiling point refrigerant are mixed is forcibly circulated in the circulation channel by the refrigerant transfer means, and the mixed refrigerant and the object to be cooled in the heat exchanger provided on the circulation channel A boiling cooling device in which heat is exchanged with
A first reservoir disposed on the circulation channel;
A first condensing unit disposed in the first storage unit;
A first temperature adjusting unit that adjusts the temperature of the first condensing unit to be equal to or higher than the boiling point of the mixed refrigerant and lower than the condensation point;
A second reservoir connected to the first reservoir by a steam passage;
A second condensing unit disposed in the second storage unit;
A second temperature adjusting unit for adjusting the temperature of the second condensing unit to a temperature lower than the temperature of the first condensing unit;
A boiling cooling device comprising: a reflux path for refluxing the mixed refrigerant stored in the second storage section to the circulation path. A first control valve is disposed on the circulation flow path downstream of the first reservoir and upstream of the heat exchanger, and a second control valve is disposed on the reflux path. And a control unit for controlling the opening and closing of the first control valve and the second control valve is further provided,
During the operation of the boiling cooling device, at least the first control valve is opened and the second control valve is closed by the control unit.
2. The boiling cooling device according to claim 1, wherein at least the second control valve is controlled by the control unit before the boiling cooling device is stopped. 3.   3. The boiling according to claim 2, wherein, before the boiling cooling device is stopped, the control is performed so that the first control valve is closed and the second control valve is opened. Cooling system.   During the operation of the boiling cooling device, at the start of the operation, the first control valve and the second control valve are opened, and the composition ratio of the low boiling point refrigerant to the entire mixed refrigerant stored in the first storage unit is The boiling cooling device according to claim 2 or 3, wherein the control unit performs control for closing the second control valve when a predetermined composition ratio is reached.   The said 2nd temperature adjustment part adjusts the temperature of a said 2nd condensation part to below the boiling point of the said mixed refrigerant, The boiling cooling device as described in any one of Claims 1-4 characterized by the above-mentioned.   The said 1st temperature adjustment part utilizes the heat received by the heat exchange with the said heat exchanger, The boiling cooling device as described in any one of Claims 1-5 characterized by the above-mentioned.

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