JP4507561B2 - Cooling system for superconducting motor vehicle - Google Patents

Description

  The present invention relates to a cooling system for a superconducting motor vehicle, and more particularly, to prevent a refrigerant such as liquid hydrogen or liquid nitrogen used for cooling a superconducting motor from running out.

  2. Description of the Related Art In recent years, in order to improve the concern about exhaustion of fuel resources such as gasoline and environmental deterioration due to exhaust gas exhausted from an internal combustion engine, development of an electric vehicle that runs by driving a motor with electricity has been advanced. When a normal conducting motor is used as the motor, there is a problem that copper loss occurs due to electrical resistance, resulting in low efficiency, and an induced current is attenuated, resulting in low output. Therefore, as disclosed in Japanese Patent Laid-Open No. 6-6907, if a superconducting motor is adopted, copper loss in the superconductor portion can be eliminated and high efficiency can be achieved, and the motor itself can be reduced in size and output. There is an advantage that can be realized.

  In order to exhibit the superconducting characteristics of the superconducting motor, it is necessary to cool to a very low temperature, and the use of liquid hydrogen, liquid nitrogen, various coolers, and the like has been studied.

However, when liquid hydrogen or liquid nitrogen is used as a refrigerant for cooling the superconducting motor, the refrigerant is vaporized by heat exchange with the superconducting motor. When liquid hydrogen is used as a refrigerant, the vaporized hydrogen is supplied to a fuel cell mounted on an electric vehicle and converted into electric energy. On the other hand, when liquid nitrogen is used as the refrigerant, the vaporized nitrogen is released to the outside as it is.
Therefore, when the superconducting motor is cooled by a liquid hydrogen or liquid nitrogen refrigerant, the refrigerant decreases, and therefore the refrigerant must be replenished.

On the other hand, when a cooler is used for cooling the superconducting motor, the cooler takes time to cool the superconducting motor, and there is a problem that a large amount of power is consumed to operate the cooler.
JP-A-6-6907

  The present invention has been made in view of the above problems, and it is an object of the present invention to display the remaining amount of refrigerant used for cooling the superconducting motor to the driver to prevent the refrigerant from running out.

To solve the above problems, the present invention includes a superconducting motor, a tank that the refrigerant for cooling the superconducting motor to savings reservoir, the coolant remaining amount measuring means mounted on the tank, and,
Monitoring means for notifying the driver's seat side of the remaining amount of refrigerant in the tank measured by the refrigerant remaining amount measuring means ;
When the refrigerant remaining amount measuring means detects that the remaining amount of refrigerant in the tank is below a certain amount, a backup cooler installed separately is operated and the superconducting motor is cooled below the set value by the cooler. There is provided a cooling system in a superconducting motor vehicle characterized by comprising means for switching to a backup mode .

  With the above configuration, since the driver is informed of the remaining amount of the refrigerant that cools the superconducting motor by the monitoring means, the driver can always know the remaining amount of the refrigerant, so that it can be used as a guide for replenishing the refrigerant. It is possible to prevent the refrigerant from running out. Examples of means for notifying the driver of the remaining amount of refrigerant include a meter display and a voice means.

  When the refrigerant remaining amount measuring means detects that the remaining amount of refrigerant in the tank is below a certain amount, a warning signal is transmitted to a display panel of the instrument panel or / and an audio output device to display a warning or / and It is preferable to provide warning means for generating an alarm sound.

  With the above configuration, when the remaining amount of the refrigerant becomes a certain amount or less, a warning is issued to the driver, and it is possible to prevent the refrigerant from running out by urging the driver to replenish the refrigerant.

Furthermore, in the present invention, as described above, when the refrigerant remaining amount measuring means detects that the refrigerant remaining amount in the tank is equal to or less than a predetermined amount, a separately mounted backup cooler is operated, and the cooling vessels by that equipped with means for switching to the backup mode to cool to below the set value the superconducting motor.

With the above configuration, when there is little remaining refrigerant for cooling the superconducting motor, a separately mounted backup cooler can be operated and the superconducting motor can be cooled by the cooler.
The cooling method of the superconducting motor with the cooler for backup is to collect again the refrigerant such as gaseous hydrogen and gaseous nitrogen that is vaporized by cooling the superconducting motor, and the refrigerant is cooled and liquefied by the cooler. The method of cooling the superconducting motor with the cooled refrigerant, or the method of cooling the superconducting motor with the liquefied refrigerant by cooling the backup cooler with helium or the like, liquefying the gaseous hydrogen or gaseous nitrogen contacting the cooler Etc.
Here, the set value is preferably 20 Kelvin or more and 77 Kelvin or less. This is because if it is higher than 77 Kelvin, the superconducting motor cannot be sufficiently cooled, and the coil of the superconducting motor cannot be brought into the superconducting state. On the other hand, if the temperature is lower than 20 Kelvin, the superconducting motor is cooled more than necessary, and power is wasted.

The refrigerant stored in the tank is preferably made of liquid nitrogen or liquid hydrogen.
By using cryogenic liquid hydrogen or liquid nitrogen as the refrigerant, the superconducting motor can be sufficiently cooled to maintain the optimum operating temperature of the superconducting material.
In addition, when liquid hydrogen is used as a refrigerant, it can be shared with the fuel source of the fuel cell, which is preferable.

  An electric vehicle or a hybrid vehicle including the superconducting motor as a driving motor, the tank including liquid nitrogen or liquid hydrogen for a fuel cell, the liquid nitrogen or liquid hydrogen in the tank It is preferably used as a cooling refrigerant for the superconducting motor and circulated from the tank to the refrigerant jacket of the superconducting motor via a pipe.

  If it is set as the said structure, since the motor for driving | running | working driving | running | working of an electric vehicle or a hybrid vehicle is made into the superconducting motor, driving | running | working of a motor vehicle can be made efficient. In addition, by providing a cooling system in the superconducting motor as the driving motor, it is possible to prevent the refrigerant that cools the superconducting motor from running out, and the refrigerant runs out during running, making the vehicle unable to run. Can be prevented.

  As is clear from the above description, according to the present invention, the remaining amount of the refrigerant that cools the superconducting motor is notified to the driver. Therefore, the driver always knows the remaining amount of the refrigerant so that the refrigerant can be replenished. It can be used as a guide, and the refrigerant can be prevented from running out.

  Further, if the driver is warned by voice or / and display when the remaining amount of the refrigerant becomes a certain amount or less, the refrigerant may run out by prompting the driver to replenish the refrigerant. Can be prevented.

Furthermore, when the remaining amount of the refrigerant becomes a certain amount or less, a backup cooler is operated and the superconducting motor is cooled by the cooler. Therefore, by cooling the superconducting motor, The vaporized refrigerant can be liquefied again by the cooler, and the superconducting motor can be cooled by the refrigerant.

Embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a reference embodiment of the present invention.

Figure 1 is a schematic diagram of an electric vehicle 10 equipped with a cooling system 100 of the referential embodiment, the electric vehicle 10 and the superconducting motor 30 as a drive source which is superconducting coils are used to drive the superconducting motor 30 And a fuel cell 12 that generates electricity by reacting hydrogen and oxygen. The cooling system 100 includes a refrigerant remaining amount measuring unit 22, a monitoring unit, and a warning unit, which will be described later.

The fuel cell 12 is supplied with hydrogen and oxygen, and generates electricity by reacting the hydrogen and oxygen. This electric power is converted from a direct current to an alternating current by a power converter (not shown), and the superconducting motor 30 is operated. Driving.
The supply of hydrogen to the fuel cell 12 will be described later.

  As shown in FIG. 2, the superconducting motor 30 has a first coil 32A, a second coil 32B, and a third coil 32C, which are superconducting coils 32 on the armature side, arranged in the circumferential direction on the inner peripheral surface of a stator 31 serving as a housing. It is installed at regular intervals of 120 °. Three-phase alternating current is supplied to the first to third coils 32A to 32C from the fuel cell 12 via the electric wires 11, respectively. The electric wires 11 are divided into three branch lines 11a and are fed to the coils 32A to 32C. ing.

In the stator 31, a field-side superconducting coil 34 is fixed to the rotational drive shaft 33 of the superconducting motor 30, and one end side of the rotational drive shaft 33 extends to drive transmission means (not shown).
The superconducting coils 32 and 34 use bismuth-based superconducting wires, but ceramic materials such as yttrium-based, thallium-based, and bismuth-based oxides may be used.

  The superconducting motor 30 is operated by a three-phase alternating current supplied from the fuel cell 12 to the first coil 32A, the second coil 32B, and the third coil 32C. A rotating magnetic field is generated in 31 and the rotation drive shaft 33 is rotated. And the rotational power of the wheel of the electric vehicle 10 is obtained by the torque of the rotational drive shaft 33 being transmitted to the drive transmission means.

  The superconducting motor 30 is disposed in a heat-insulating refrigerant jacket 13, and a liquid hydrogen pipe 14 for supplying liquid hydrogen from a liquid hydrogen tank 20 is connected to the refrigerant jacket 13. The liquid hydrogen tank 20 is disposed in a cooling device 21, and the cooling device 21 cools the liquid hydrogen in the liquid hydrogen tank 20 to a cryogenic temperature of about 20 Kelvin. The liquid hydrogen cooled to a very low temperature by the cooling device 21 is supplied to the refrigerant jacket 13 through the liquid hydrogen pipe 14 and used to cool the superconducting motor 30.

  The liquid hydrogen tank 20 is equipped with a refrigerant remaining amount measuring means 22 for measuring the remaining amount of liquid hydrogen, and the refrigerant remaining amount measuring means 22 is connected to a pressure detector 40 as shown in FIG. , A repeater 41 and a converter 42. The pressure detector 40 is mounted in the liquid hydrogen tank 20, while the relay 41 and the converter 42 are disposed in the vicinity outside the liquid hydrogen tank 20.

  The pressure detector 40 is provided with a differential pressure detection sensor 48 facing the pressure introduction port 43 a provided in the case 43, and the differential pressure detection sensor 48 includes a bellows 44, a pressure measurement spring 45, an iron core 46, and a coil 47. I have. In the differential pressure sensor 48, the iron core 46 moves against the urging force of the pressure measuring spring 45 in accordance with the difference in pressure acting on the case 43 outside the case 43 and the inside of the case 43, and the coil 47 generated by this movement. The pressure difference between the inside and outside of the bellows 44 is detected from the change in output.

  The pressure detector 40 is connected via a single hollow cable 51 including signal lines 49a and 49b for transmitting an output signal of the differential pressure detection sensor 48 and an atmospheric pressure introduction pipe 50 made of a flexible pipe member. It is connected to the repeater 41. One end of the atmospheric pressure introduction pipe 50 opens in the case 43 of the pressure detector 40, and the other end opens in the case 52 of the repeater 41, and the atmosphere 52 is introduced into the case 52 of the repeater 41. A mouth 53 is provided. Therefore, atmospheric pressure is introduced into the case 43 of the pressure detector 40 through the atmospheric pressure introduction port 53, the inside of the case 52 of the relay 41, and the atmospheric pressure introduction pipe 50.

  The signal lines 49 a and 49 b of the differential pressure detection sensor 48 are connected to a substrate 54 in the case 52 of the repeater 41, and a circuit (not shown) provided on the substrate 54 outputs an output signal of the differential pressure detection sensor 48. Outputs the current according to. The substrate 54 is connected to the converter 42 that supplies power by a cable 56 including signal lines 55a and 55b. The converter 42 is connected to the display panel 23 of the instrument panel and the sound output device 24 for displaying the remaining amount of liquid hydrogen derived from the measured water pressure via the transmission line w.

  The remaining amount of liquid hydrogen in the liquid hydrogen tank 20 measured by the refrigerant remaining amount measuring means 22 is transmitted to the display plate 23 via the transmission line w and provided on the display plate 23 of the instrument panel shown in FIG. The liquid hydrogen refrigerant remaining amount meter 25 (monitoring means) displays the remaining amount of liquid hydrogen and the distance the vehicle can travel with the remaining liquid hydrogen.

The cooling system according to this reference embodiment includes a warning means comprising warning lamp 26 and audio output device 24 provided in the display panel 23. When the remaining amount of liquid hydrogen in the liquid hydrogen tank 20 falls below a certain amount, a warning signal is transmitted from the refrigerant remaining amount measuring means 22 to the display board 23 and the audio output device 24 via the transmission line w, and the warning lamp 26 Flashes and displays a warning, and the audio output machine 24 emits a warning sound to warn the driver that the remaining amount of liquid hydrogen is small.

  The refrigerant jacket 13 containing the superconducting motor 30 is provided with a vaporized refrigerant extraction port 15, and the vaporized refrigerant extraction port 15 is connected to the fuel cell 12 through a hydrogen gas pipe 16. . The liquid hydrogen supplied from the liquid hydrogen tank 20 to the refrigerant jacket 13 is vaporized by cooling the superconducting motor 30, and the vaporized hydrogen is extracted from the vaporized refrigerant extraction port 15, and is passed through the hydrogen gas pipe 16 to the fuel cell 12. To be used as fuel for power generation.

With the above configuration, the remaining amount of liquid hydrogen used as the refrigerant for cooling the superconducting motor 30 is displayed to the driver by the refrigerant remaining amount meter 25, so that the driver can always grasp the remaining amount of liquid hydrogen. If the remaining amount of liquid hydrogen falls below a certain level, a warning is issued to the driver by the warning lamp 26 and voice, and the liquid hydrogen is cut off by urging the driver to replenish liquid hydrogen. It can be prevented in advance.
In addition, the vehicle equipped with the cooling system is not limited to an electric vehicle but may be a hybrid vehicle.
Further, the superconducting motor cooled by the cooling system is not limited to a motor for driving the automobile, but may be used as a motor for operating equipment in the automobile.

Figure 5 shows an implementation form of the present invention.
Cooling system 100 'of the present embodiment, the reference first embodiment and similar to the refrigerant amount measuring means 22', the monitoring means, in addition to the warning means, and a condenser 27 for backup.

  In this embodiment, liquid nitrogen is used as a refrigerant for cooling the superconducting motor 30, and the power source for driving the superconducting motor 30 is not a fuel cell but a conventionally used battery 17. Also, the backup cooler 27 is mounted in the refrigerant jacket 13 ', and the cooler 27 is connected to the refrigerant remaining amount measuring means 22' in the liquid nitrogen tank 20 'by a transmission line w'. Yes. Further, no piping is connected to the vaporized refrigerant extraction port 15 ′ of the refrigerant jacket 13 ′, and the nitrogen vaporized by cooling of the superconducting motor 30 is the vaporized refrigerant extraction port until the remaining amount of liquid nitrogen becomes a certain amount or less. 15 'is discharged to the outside as it is.

Similar to the reference embodiment, the remaining amount of liquid nitrogen in the liquid nitrogen tank 20 ′ is measured by the refrigerant remaining amount measuring means 22 ′ and displayed by the refrigerant remaining amount meter 25. When the remaining amount of liquid nitrogen falls below a certain level, the warning lamp 26 blinks and displays a warning, and the sound output device 24 'emits a warning sound and the remaining amount of liquid nitrogen is small for the driver. Warning. In the present embodiment, when the remaining amount of liquid nitrogen becomes a certain amount or less, a signal is transmitted from the refrigerant remaining amount measuring means 22 ′ to the cooler 27 in the refrigerant jacket 13 ′, and the cooler 27 starts to operate. Nitrogen vaporized by the vessel 27 is collected, cooled to 20 Kelvin, liquefied again, and switched to a backup mode in which the superconducting motor 30 is cooled by the liquid nitrogen. Therefore, even if the liquid nitrogen supplied from the liquid nitrogen tank 20 ′ runs out, the superconducting motor 30 can be cooled by the liquefied liquid nitrogen again, so that the driving of the electric vehicle 10 ′ can be continued. At this time, the vaporized refrigerant extraction port 15 'is closed so that the vaporized nitrogen is not released to the outside.
Note that the backup cooler 27 may be cooled with helium or the like, gaseous nitrogen in contact with the cooled cooler 27 may be liquefied, and the superconducting motor may be cooled with the liquefied liquid nitrogen.
In addition, since other configurations and functions and effects are the same as those of the reference embodiment, the same reference numerals are given and description thereof is omitted.

It is a schematic diagram of an electric vehicle reference implementation of the invention. It is drawing which shows the superconducting motor for an electric vehicle drive. It is drawing which shows a refrigerant | coolant residual amount measurement means. It is drawing which shows a display board. It is a schematic diagram of an electric vehicle of the implementation of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electric vehicle 11 Electric wire 11a Branch line 12 Fuel cell 13 Refrigerant jacket 14 Liquid hydrogen piping 15 Vaporized refrigerant extraction port 16 Hydrogen gas piping 17 Battery 20 Liquid hydrogen tank 21 Liquid hydrogen cooling device 22 Refrigerant remaining amount measuring means 23 Display Plate 24 Audio output machine 25 Refrigerant remaining amount meter 26 Warning lamp 27 Backup cooler 30 Superconducting motor 31 Stator 32 Superconducting coil 34 on the element side Superconducting coil 33 on the field side Rotation drive shaft 100 Cooling system

Claims (4)

Comprising a superconducting motor, a tank that the refrigerant for cooling the superconducting motor to savings reservoir, the coolant remaining amount measuring means mounted on the tank, and,
Monitoring means for notifying the driver's seat side of the remaining amount of refrigerant in the tank measured by the refrigerant remaining amount measuring means ;
When the refrigerant remaining amount measuring means detects that the remaining amount of refrigerant in the tank is below a certain amount, a backup cooler installed separately is operated and the superconducting motor is cooled below the set value by the cooler. A cooling system for a superconducting motor vehicle characterized by comprising means for switching to a backup mode .   When the refrigerant remaining amount measuring means detects that the remaining amount of refrigerant in the tank is below a certain amount, a warning signal is transmitted to a display panel of the instrument panel or / and an audio output device to display a warning or / and The cooling system for a superconducting motor vehicle according to claim 1, further comprising warning means for generating an alarm sound. The cooling system for a superconducting motor vehicle according to claim 1 or 2, wherein the refrigerant stored in the tank comprises liquid nitrogen or liquid hydrogen . An electric vehicle or a hybrid vehicle including the superconducting motor as a driving motor, the tank including liquid nitrogen or liquid hydrogen for a fuel cell, the liquid nitrogen or liquid hydrogen in the tank The cooling system for a superconducting motor vehicle according to any one of claims 1 to 3 , wherein the cooling system is used as a cooling refrigerant for a superconducting motor and is circulated from the tank to a refrigerant jacket of the superconducting motor via a pipe .

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