JP6420201B2 - Air separation device - Google Patents

Description

  The present invention relates to an air separation device for separating raw material air by a cryogenic separation method.

  In the case of producing oxygen and nitrogen on a large scale by separating air, a cryogenic separation method is currently widely used. In the cryogenic separation method, air is liquefied and distilled (rectification) using a difference in boiling points between oxygen and nitrogen to separate air into oxygen and nitrogen. The reason for the cryogenic separation is that the liquefaction temperature of air is around -170 to -190 ° C., and the cryogenic separation method is carried out in an insulated cryogenic system.

  The air separation apparatus using the cryogenic separation method includes a rectifying column, and the rectifying column is purified by gas-liquid separation by cooling the raw air to the liquefaction temperature of nitrogen and oxygen which are the composition of the raw air. Produces high nitrogen and oxygen.

  As an air separation device using a cryogenic separation method, there is an air separation device provided with a condensing circuit for refluxing nitrogen (see, for example, Patent Documents 1 and 2). The condensing circuit liquefies part of the nitrogen (product nitrogen) extracted from the rectification column and returns it to the rectification column. According to this air separation device, it is provided with a nitrogen condensing circuit, thereby giving the heat of nitrogen condensation as the heat of evaporation of oxygen, so that the amount of heat circulation increases, so compared to an air separation device without a condensing circuit, It is known that the energy consumption of air separation devices can be reduced by 20-30%.

Japanese Patent No. 5415192 Japanese Patent No. 5684058

  In recent years, there has been a strong demand for energy saving due to suppression of global warming and rising energy prices, and air separation devices are no exception.

  An object of the present invention is to save energy with respect to an air separation apparatus including a condensing circuit that liquefies a part of nitrogen in a gaseous state taken out from a rectification column and returns it to the rectification column.

  An air separation apparatus according to the present invention includes a rectifying column that cryogenically separates raw material air in a liquid state to generate gaseous nitrogen, and a part of the gaseous nitrogen extracted from the rectifying column. A condensing circuit for supplying nitrogen, changing the supplied nitrogen from a gaseous state to a liquid state and returning the nitrogen to the rectification column, and a cooling circuit, the condensing circuit having a critical temperature higher than the boiling point of liquid nitrogen. A superconducting motor including a superconducting magnet composed of a superconducting material, and a compression unit that is driven by the superconducting motor and compresses nitrogen in a gas state flowing through the condensing circuit, and the cooling circuit includes the condensing circuit. The superconducting magnet is cooled to the critical temperature or lower using flowing nitrogen in the liquid state or nitrogen in the gas state before flowing through the condensation circuit and being led to the compression unit.

  The superconducting motor is used in a state where the superconducting magnet is cooled below the critical temperature of the superconducting material constituting the superconducting magnet. For cooling the superconducting magnet, a refrigerant having a temperature lower than the critical temperature is used. In order to make the temperature of the refrigerant below the critical temperature, a refrigerator is required, but this increases the energy consumption of the air separation device.

  In the air separation device according to the present invention, liquid or gaseous nitrogen flowing in a condensing circuit for refluxing nitrogen is used as a refrigerant for cooling the superconducting magnet to a critical temperature or lower. Therefore, according to the air separation device of the present invention, since a refrigerator is not required, energy saving of the air separation device can be achieved.

  When nitrogen in the gaseous state is used as the refrigerant, the nitrogen in the gaseous state before being introduced to the compression unit is because this nitrogen is a boil-off gas and has a temperature of 77 K (the boiling point of liquefied nitrogen).

  In the above-described configuration, the condensing circuit further includes a first flow path that connects the rectification column and the compression unit and guides nitrogen in a gaseous state supplied from the rectification column to the compression unit, The cooling circuit is connected to the first flow path, and a second flow path for supplying a part of the gaseous nitrogen flowing through the first flow path to the superconducting magnet; the first flow path; A third flow path that is connected and returns the nitrogen in the gaseous state supplied to the superconducting magnet by the second flow path to the first flow path.

  In this configuration, the superconducting magnet is cooled to a critical temperature or lower using nitrogen in a gas state before flowing into the condensing circuit and being led to the compression unit.

  In the above configuration, the condensing circuit expands the nitrogen in a gas state compressed by the compression unit, thereby expanding an expansion unit that changes nitrogen from a gas state to a liquid state, the expansion unit, and the rectification tower. And a fourth flow path for guiding nitrogen in a liquid state to the rectification tower, wherein the cooling circuit is connected to the fourth flow path and flows in the fourth flow path A fifth flow path for supplying a part of the nitrogen to the superconducting magnet and the fourth flow path, and the liquid nitrogen supplied to the superconducting magnet by the fifth flow path is supplied to the superconducting magnet. A sixth flow path returning to the fourth flow path.

  When a sudden load change or the like occurs during operation of the superconducting motor, the superconducting motor generates heat due to eddy current. If the superconducting state is broken at a minute portion of the superconducting magnet due to this heat generation, heat is locally generated from the superconducting magnet, which may cause damage to the superconducting motor.

  Therefore, when heat generation due to the eddy current occurs, it is necessary to quickly cool the heat generation. Liquid has a larger heat transfer coefficient than gas. According to this configuration, since the superconducting magnet is cooled using liquid nitrogen (that is, liquefied nitrogen), even if heat is generated by the eddy current, the heat can be quickly cooled.

  In the above configuration, the cooling circuit is connected to the rectifying column instead of the sixth flow channel, and the nitrogen in the liquid state supplied to the superconducting magnet by the fifth flow channel is used as the rectifying column. A seventh flow path leading to

  Since the pressure in the rectifying column is lower than that in the fourth channel, the liquid nitrogen supplied to the superconducting coil by the fifth channel is returned to the rectifying column rather than returning to the fourth channel. Returning can return nitrogen in a liquid state to the rectification column more quickly. Therefore, according to this configuration, the cooling efficiency of the superconducting magnet can be increased.

  In the above configuration, the cooling circuit includes a first valve unit that adjusts a flow rate of nitrogen in a liquid state flowing through the fifth channel or the seventh channel, and a first temperature that measures the temperature of the superconducting magnet. When the temperature measured by the first measurement unit and the temperature measured by the first measurement unit is smaller than a predetermined value equal to or lower than the critical temperature, the flow rate of liquid nitrogen supplied to the superconducting magnet decreases, and the first When the temperature measured by one measuring unit is larger than the predetermined value, the flow rate of liquid nitrogen supplied to the superconducting magnet increases, and the temperature measured by the first measuring unit is And a first control unit that controls an opening / closing amount of the first valve unit so that a flow rate of liquid nitrogen supplied to the superconducting magnet does not change at a predetermined value.

  According to this configuration, it is possible to automatically control the temperature of the superconducting coil to a predetermined value while minimizing the amount of nitrogen in the liquid state supplied to the superconducting magnet.

  Further, according to this configuration, since the temperature of the superconducting magnet is directly measured, the temperature of the superconducting magnet can be accurately controlled.

  In the above-described configuration, the cooling circuit measures the temperature of the liquid nitrogen flowing through the seventh flow path, and the second valve unit that adjusts the flow rate of liquid nitrogen flowing through the fifth flow path. When the temperature measured by the second measuring unit and the second measuring unit is smaller than a predetermined value below the critical temperature, the flow rate of liquid nitrogen supplied to the superconducting magnet is reduced, When the temperature measured by the second measuring unit is larger than the predetermined value, the flow rate of liquid nitrogen supplied to the superconducting magnet increases, and the temperature measured by the second measuring unit is A second control unit that controls an opening / closing amount of the second valve unit so that a flow rate of liquid nitrogen supplied to the superconducting magnet does not change at the predetermined value.

  According to this configuration, it is possible to automatically control the temperature of the superconducting magnet to a predetermined value while minimizing the amount of liquid nitrogen supplied to the superconducting magnet.

  Further, according to this configuration, when the temperature of the superconducting magnet cannot be directly measured for some reason, the temperature of the superconducting magnet is estimated by indirectly estimating the temperature of the superconducting magnet from the temperature of nitrogen in the liquid state flowing through the seventh flow path. To control.

  In the above configuration, the cooling circuit is provided downstream of a connection portion between the fourth flow path and the fifth flow path, and adjusts a flow rate of nitrogen in a liquid state flowing through the fourth flow path. 3, and the first control unit controls the opening / closing amount of the first valve unit in a state where the third valve unit is opened, and the first valve unit When the temperature measured by the first measuring unit is larger than the predetermined value in a fully open state, the third valve unit is controlled to close by a predetermined amount.

  According to this configuration, when the first valve unit is fully open and the temperature measured by the first measurement unit is greater than a predetermined value, the first control unit turns the third valve unit on. Control to close a predetermined amount. As a result, the amount of nitrogen in the liquid state flowing through the fourth flow path can be reduced and the amount of nitrogen in the liquid state flowing through the fifth flow path can be increased, so that the superconducting magnet can be further cooled.

  In the above configuration, the cooling circuit is provided downstream of a connection portion between the fourth flow path and the fifth flow path, and adjusts a flow rate of nitrogen in a liquid state flowing through the fourth flow path. 3, and the second control unit controls the opening / closing amount of the second valve unit with the third valve unit opened. The second valve unit When the temperature measured by the second measuring unit is larger than the predetermined value in a fully open state, the third valve unit is controlled to be closed by a predetermined amount.

  According to this configuration, the second control unit moves the third valve unit when the second valve unit is fully opened and the temperature measured by the second measurement unit is greater than a predetermined value. Control to close a predetermined amount. As a result, the amount of nitrogen in the liquid state flowing through the fourth flow path can be reduced and the amount of nitrogen in the liquid state flowing through the fifth flow path can be increased, so that the superconducting magnet can be further cooled.

  In the above configuration, the rectification column cryogenicly separates the raw material air in a liquid state to generate liquid oxygen, and the condensing circuit includes the liquid oxygen extracted from the rectification column and the compression It further includes a heat exchanging unit that cools the gaseous nitrogen and changes the liquid oxygen to the gaseous state by exchanging heat with the gaseous nitrogen compressed by the unit.

  According to this configuration, since the compressed gaseous nitrogen is cooled using the liquid oxygen stored in the rectification column, a new refrigerant for cooling the compressed gaseous nitrogen is prepared. There is no need to do.

  The said structure WHEREIN: The heat insulation airtight container which accommodates the said superconducting motor and the said compression part is further provided.

  According to this configuration, the superconducting motor and the compression unit are accommodated in the heat-insulated sealed container, thereby unitizing them. Therefore, the assembly work of the condensation circuit can be facilitated.

  ADVANTAGE OF THE INVENTION According to this invention, energy saving can be achieved regarding an air separation apparatus provided with the condensation circuit which liquefies some nitrogen among the gaseous nitrogen taken out from the rectification tower, and returns it to a rectification tower.

It is a block diagram which shows the structure of the air separation apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure of the air separation apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the air separation apparatus which concerns on 3rd Embodiment. It is a block diagram which shows the structure of the air separation apparatus which concerns on 4th Embodiment. In 4th Embodiment, it is a block diagram which shows the relationship between a 1st valve part, a 1st measurement part, and a 1st control part. In 4th Embodiment, it is a flowchart explaining control of the 1st valve part. It is a block diagram which shows the structure of the air separation apparatus which concerns on 5th Embodiment. In 5th Embodiment, it is a block diagram which shows the relationship between a 2nd valve part, a 2nd measurement part, and a 2nd control part. It is a block diagram which shows the structure of the air separation apparatus which concerns on 6th Embodiment. In 6th Embodiment, it is a block diagram which shows the relationship between a 1st valve part, a 3rd valve part, a 1st measurement part, and a 1st control part. In 6th Embodiment, it is a flowchart explaining control of the 1st valve part and the 3rd valve part. It is a block diagram which shows the structure of the air separation apparatus which concerns on 7th Embodiment. In 7th Embodiment, it is a block diagram which shows the relationship between a 2nd valve part, a 3rd valve part, a 2nd measurement part, and a 2nd control part. It is a schematic diagram of the heat insulation airtight container which accommodates the superconducting motor and the compression part. It is sectional drawing which shows the structure of a superconducting motor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the structure which attached | subjected the same code | symbol shows that it is the same structure, The description is abbreviate | omitted about the content which has already demonstrated the structure.

  FIG. 1 is a configuration diagram showing a configuration of an air separation device 1a according to the first embodiment. The air separation device 1 a includes a compression unit 2, a heat exchange unit 3, an expansion unit 4, a rectification tower 5, a condensation circuit 6, and a cooling circuit 7. The first embodiment and the second to seventh embodiments described later are different in the configuration of the cooling circuit 7. The cooling circuit 7 of the first embodiment cools the superconducting coil 601 provided in the superconducting motor 60 using, for example, nitrogen in a gaseous state having a temperature of 77K.

  The compression unit 2 is a compressor that adiabatically compresses raw material air at room temperature. Thereby, the temperature of raw material air becomes higher than room temperature. The raw material air adiabatically compressed by the compression unit 2 flows through the flow path 8 a and is sent to the heat exchange unit 3. The flow path 8a, and the flow paths 8b to 8o and the flow paths 70a to 70e, which will be described later, are also referred to as pipes or lines.

  The heat exchange unit 3 is connected to a flow path 8a, a flow path 8b, a flow path 8c, a flow path 8d, a flow path 8e, and a flow path 8f. As described above, the raw material air adiabatically compressed by the compression unit 2 flows through the flow path 8 a and is sent to the heat exchange unit 3. The product nitrogen taken out from the rectification column 5 flows through the flow path 8b and is sent to the heat exchange unit 3. The product oxygen taken out from the rectification column 5 flows through the flow path 8 c and is sent to the heat exchange unit 3.

  The heat exchange unit 3 is a heat exchanger that performs the following two heat exchanges. The heat exchanging unit 3 performs heat exchange between the raw material air that has been adiabatically compressed in the compressing unit 2 and the raw material air having a temperature of, for example, about room temperature, and the product nitrogen in a gaseous state having a temperature of 77 K sent from the rectifying tower 5. Increase the temperature of the product nitrogen. The heat exchanging unit 3 exchanges heat between the raw material air that is adiabatically compressed by the compressing unit 2 and the raw material air having a temperature of, for example, about room temperature, and the product oxygen in a liquid state having a temperature of 90 K sent from the rectifying column 5. To increase the product oxygen temperature.

  The product nitrogen and product oxygen exchanged by the heat exchange unit 3 flow through the flow path 8d and the flow path 8e, respectively, and are sent to the next step. The raw material air adiabatically expanded in the compression unit 2 is cooled by supplying heat to the product nitrogen and product oxygen in the heat exchange unit 3, flows through the flow path 8 f, and is sent to the expansion unit 4.

  The expansion part 4 is an expansion turbine that adiabatically expands the supplied raw material air. An expansion valve can be used as the expansion unit 4 instead of the expansion turbine.

  The raw material air that has been adiabatically expanded in the expansion section 4 to be in a liquid state flows through the flow path 8 g and is sent to the rectification tower 5.

  The rectifying column 5 is a single type (one-column type), and cryogenic-separates liquid source air to generate gaseous nitrogen and liquid oxygen. Nitrogen is stored in the upper part of the rectifying column 5, and oxygen is stored in the lower part of the rectifying column 5. As the rectification column 5, a double system (two-column system) can be used instead of a single system.

  A flow path 8 h is connected to the top of the rectifying column 5. Nitrogen (boil-off gas) in a gaseous state having a temperature of 77 K taken out from the rectification column 5 flows through the flow path 8h. The flow path 8h is branched into a flow path 8b and a flow path 8i. The nitrogen in the gaseous state flowing through the flow path 8h flows through the flow path 8b and is sent to the heat exchange unit 3, or flows through the flow path 8i and is sent to the condensation circuit 6 described later.

  A flow path 8j is connected to the bottom of the rectifying column 5. The flow path 8j is branched into a flow path 8c and a flow path 8k. The liquid oxygen flowing through the flow path 8j flows through the flow path 8c and is sent to the heat exchange unit 3 or flows through the flow path 8k and is sent to the heat exchange unit 62.

  The condensing circuit 6 is a module to which a part of the nitrogen in the gaseous state taken out from the rectifying column 5 is supplied, and the supplied nitrogen is changed from the gaseous state to the liquid state and returned to the rectifying column 5. is there. Since the condensing circuit 6 makes a part of the nitrogen that has been changed from a liquid state to a gas state in the rectification column 5 again into a liquid state, the condensing circuit 6 can also be referred to as a recondensing circuit.

  The condensing circuit 6 includes a superconducting motor 60, a compression unit 61, a heat exchange unit 62, an expansion unit 63, and a flow path (flow path 8i, flow path 81, flow path 8m, flow path 8o).

  Superconducting motor 60 is a motor that rotates a rotor using a superconducting magnet. The superconducting magnet is, for example, a magnet composed of a superconducting coil 601 and a magnetic core around which it is wound, or a superconducting bulk magnet. In the present embodiment, the former magnet will be described as an example.

Superconducting coil 601 is cooled below the critical temperature of the superconducting material constituting the coil by cooling circuit 7 described later. The refrigerant for cooling the superconducting coil 601 is nitrogen having a temperature of 77K. Therefore, the superconducting material constituting the superconducting coil 601 must have a critical temperature higher than 77K. As such a superconducting material, for example, there are Bi-based (Bi ₂ Sr ₂ Ca ₂ Cu ₃ O _y ) and Y-based (YBa ₂ Cu ₃ O ₇ ). 77K is the boiling point of liquid nitrogen (ie, liquefied nitrogen).

  The flow path 8 i is connected to the compression unit 61. The nitrogen in the gas state flowing through the flow path 8 i is sent to the compression unit 61. The first flow path is configured by the flow path 8h and the flow path 8i. The first flow path connects the rectification column 5 and the compression unit 61, and guides nitrogen in the gaseous state supplied from the rectification column 5 to the compression unit 61.

  The compression unit 61 is driven by the superconducting motor 60 and adiabatically compresses gaseous nitrogen flowing in the flow path 8i (that is, flowing in the condensation circuit 6). The compression unit 61 is, for example, a screw type compressor. The rotation shaft 603 of the superconducting motor 60 is directly or indirectly connected to a screw (not shown) of the compression unit 61. The driving force of the superconducting motor 60 is transmitted to the screw via the rotating shaft 603, and the screw rotates.

  The heat exchange unit 62 is connected to a flow path 8k, a flow path 81, a flow path 8m, and a flow path 8n. The gaseous nitrogen adiabatically compressed by the compression unit 61 flows through the flow path 8 l and is sent to the heat exchange unit 62. The liquid oxygen stored in the rectification column 5 flows through the flow path 8j and the flow path 8k and is sent to the heat exchange unit 62.

  The heat exchanging unit 62 exchanges heat between nitrogen in the gas state adiabatically compressed by the compressing unit 61 and oxygen in a liquid state having a temperature of 90 K sent from the rectifying tower 5, so that the oxygen is converted from the liquid state. Change to gaseous state. Since adiabatic-compressed gaseous nitrogen exchanges heat with liquid oxygen having a temperature of 90K, the temperature of nitrogen needs to be higher than 90K by adiabatic compression.

  Oxygen is changed from a liquid state to a gaseous state using nitrogen whose temperature has been increased by adiabatic compression. For this reason, when the difference between the temperature of the gaseous nitrogen flowing through the flow path 8l and the temperature of the liquid oxygen flowing through the flow path 8k is large, the amount of increase in the temperature of the gaseous nitrogen must be large. The power to compress the nitrogen in the state increases. Conversely, when the temperature difference between them is small, the amount of increase in the temperature of the gaseous nitrogen may be small, so that the power for compressing the gaseous nitrogen can be reduced.

  Since the compressed gaseous nitrogen is cooled using the liquid oxygen stored in the rectifying column 5, it is not necessary to prepare a new refrigerant for cooling the compressed gaseous nitrogen.

  The nitrogen in the gas state adiabatically compressed by the compression unit 61 is lowered in temperature by supplying heat to oxygen by the heat exchange unit 62, flows through the flow path 8 m, and is sent to the expansion unit 63.

  The expansion part 63 is an expansion valve that adiabatically expands the sent nitrogen. An expansion turbine can be used as the expansion unit 63 instead of the expansion valve.

  The nitrogen condensed and liquefied in the heat exchange section 62 flows through the flow path 8m and is sent to the expansion section 63. The nitrogen is adiabatically expanded in the expansion section 63, the temperature is lowered, and flows through the flow path 8o. Returned to

  Thus, the nitrogen in the gas state adiabatically compressed by the compression unit 61 is condensed and liquefied by being cooled by the liquid state oxygen supplied from the rectification tower 5 in the heat exchange unit 62, and then The temperature is lowered by adiabatic expansion at the expansion portion 63. Therefore, nitrogen can be made into a liquid state without newly providing a cold heat source.

  Oxygen that has been changed to a gas state in the heat exchange section 62 flows through the flow path 8 n and is sent to the rectification column 5. This gaseous oxygen is reliquefied in the rectification column 5.

  The air separation device 1a produces product nitrogen and product oxygen from the raw air by repeating the above processing.

  The cooling circuit 7 cools the superconducting coil 601 included in the superconducting motor 60 below the critical temperature of the superconducting material constituting the coil. The cooling circuit 7 includes a flow path 70a (second flow path) and a flow path 70b (third flow path).

  The flow path 70 a is connected to the flow path 8 i (first flow path), and supplies a part of nitrogen in a gaseous state having a temperature of 77 K flowing through the flow path 8 i to the superconducting coil 601 of the superconducting motor 60. Thereby, the superconducting coil 601 is cooled below the critical temperature. When nitrogen in the gaseous state is used as the refrigerant, the nitrogen in the gaseous state before being introduced to the compressing unit 61 is because this nitrogen is a boil-off gas and has a temperature of 77 K (the boiling point of liquefied nitrogen).

  The flow path 70b is connected to the flow path 8i downstream from the flow path 70a, and returns nitrogen in the gaseous state supplied to the superconducting coil 601 by the flow path 70a to the flow path 8i. The nitrogen flows through the flow path 8 i and is sent to the compression unit 61.

  The main effects of the first embodiment will be described. The air separation device 1a according to the first embodiment can save energy from the following viewpoints.

  When the motor that drives the screw of the compression unit 61 is a normal conducting motor, a thermal load is generated due to copper loss in the coil of the normal conducting motor. For example, when the rotating shaft of the normal conducting motor is directly connected to the screw of the compression unit 61, the normal conducting motor must be installed in the same environment as the condensing circuit 6 (an environment where 77K of nitrogen exists). The heat load caused by the motor raises the temperature of the environment. When a normal conducting motor is installed in a room temperature environment and the rotating shaft of the normal conducting motor and the screw of the compression unit 61 are connected by a shaft through a heat insulating layer, the heat load caused by the heat entering from this shaft is reduced. Increase the temperature of the environment.

  Since this heat input needs to be supplemented by the compression work of the raw material air, even if the condensing circuit 6 is provided, the effect of reducing the energy consumption of the air separation device 1a is reduced.

  In the first embodiment, the motor that drives the screw of the compression unit 61 is the superconducting motor 60. The superconducting coil 601 in the superconducting state does not generate heat because its resistance is zero. For this reason, the loss generated in the condensing circuit 6 includes the mechanical loss generated in the compression unit 61 and the like, the fluid (nitrogen, oxygen) flowing through the flow path (for example, the flow path 8i, the flow path 8k) of the condensing circuit 6 and these. Only the fluid loss due to the friction with the flow path. For this reason, the heat load which arises when the air separation apparatus 1a is provided with the condensation circuit 6 can be reduced significantly.

  Superconducting motor 60 is used in a state where superconducting coil 601 is cooled below the critical temperature of the superconducting material constituting superconducting coil 601. For cooling the superconducting coil 601, a refrigerant having a boiling point below the critical temperature is used.

  In the air separation device 1a according to the first embodiment, nitrogen flowing through the condensing circuit 6 that circulates nitrogen is used as a refrigerant for cooling the superconducting coil 601 to a critical temperature or lower. Therefore, according to the air separation device 1a according to the first embodiment, the amount of heat input is reduced as compared with the case where the normal conducting motor is used, so that energy saving can be achieved.

  The second embodiment will be described with a focus on differences from the first embodiment shown in FIG. FIG. 2 is a configuration diagram illustrating a configuration of an air separation device 1b according to the second embodiment. The cooling circuit 7 of the second embodiment cools the superconducting coil 601 by using liquid nitrogen having a temperature of 77K.

  The flow path 8 o is a fourth flow path that connects the expansion unit 63 and the rectifying tower 5 and guides liquid nitrogen to the rectifying tower 5.

  The cooling circuit 7 includes a flow path 70c (fifth flow path) and a flow path 70d (sixth flow path). The flow path 70c is connected to the flow path 8o, and supplies a part of the liquid nitrogen having a temperature of 77K flowing through the flow path 8o to the superconducting coil 601. Thereby, the superconducting coil 601 is cooled below the critical temperature.

  The flow path 70d is connected to the flow path 8o downstream from the flow path 70c, and returns nitrogen in the gaseous state supplied to the superconducting coil 601 by the flow path 70c to the flow path 8o. This nitrogen flows through the flow path 8 o and is sent to the rectification column 5.

  The main effects of the second embodiment will be described. The temperature of the nitrogen in the gas state that is taken out from the rectification column 5 and flows through the flow path 8i is approximately the same as the temperature of the nitrogen in the liquid state that flows through the flow path 8o. It can be cooled below the critical temperature.

  When a sudden load change or the like occurs during operation of the superconducting motor 60, the superconducting motor 60 generates heat due to eddy current. If the superconducting state is broken at a minute portion of the superconducting coil 601 due to this heat generation, heat is generated locally from this, and the superconducting motor 60 may be damaged due to this.

  Therefore, when heat generation due to the eddy current occurs, it is necessary to quickly cool the heat generation. Liquid has a larger heat transfer coefficient than gas. In the second embodiment, since the superconducting coil 601 is cooled using nitrogen in a liquid state (that is, liquefied nitrogen), even if heat generation due to the eddy current occurs, the heat generation can be quickly cooled.

  The third embodiment will be described with a focus on differences from the second embodiment shown in FIG. FIG. 3 is a configuration diagram showing a configuration of an air separation device 1c according to the third embodiment. The cooling circuit 7 of the third embodiment includes a flow path 70e (seventh flow path) instead of the flow path 70d (sixth flow path) shown in FIG. The flow path 70 e is connected to the rectification column 5, and guides liquid nitrogen supplied to the superconducting coil 601 through the flow path 70 c (fifth flow path) to the rectification column 5.

  The main effects of the third embodiment will be described. Since the pressure in the rectifying column 5 is lower than that in the flow path 8o, the liquid state nitrogen supplied to the superconducting coil 601 by the flow path 70c is returned to the flow path 8o depending on the shape of the flow path in the middle. However, returning to the rectification column 5 can quickly return liquid nitrogen to the rectification column 5.

  The fourth embodiment will be described with a focus on differences from the third embodiment shown in FIG. FIG. 4 is a configuration diagram showing a configuration of an air separation device 1d according to the fourth embodiment. FIG. 5 is a block diagram illustrating a relationship among the first valve unit 71, the first measurement unit 72, and the first control unit 73 in the fourth embodiment. The cooling circuit 7 of the fourth embodiment includes a first valve unit 71, a first measurement unit 72, and a first control unit 73.

  Referring to FIGS. 4 and 5, the first valve portion 71 is an electromagnetic valve that adjusts the flow rate of nitrogen in a liquid state that flows through the flow path 70 e (seventh flow path). The first valve portion 71 may be installed in the flow path 70c (fifth flow path) to adjust the flow rate of liquid nitrogen flowing through the flow path 70c.

  The first measurement unit 72 is a temperature sensor that measures the temperature of the superconducting coil 601. The measuring element 721 of the first measuring unit 72 may be in contact with the superconducting coil 601 or may not be in contact.

  The first control unit 73 includes a CPU, a RAM, and a ROM, and realizes the following functions. A predetermined value below the critical temperature of the superconducting material constituting the superconducting coil 601 is set as a reference value. When the temperature measured by the first measurement unit 72 is equal to or lower than a reference value (that is, a predetermined value), the first control unit 73 reduces the flow rate of liquid nitrogen supplied to the superconducting coil 601. When the temperature measured by the first measuring unit 72 is larger than the reference value, the flow rate of liquid nitrogen supplied to the superconducting coil 601 increases, and the temperature measured by the first measuring unit 72 is the reference value. At this time, the opening / closing amount of the first valve portion 71 is controlled so that the flow rate of liquid nitrogen supplied to the superconducting coil 601 does not change.

  The reference value may be a pinpoint value (for example, 77K) or a value having a range (for example, 70K to 77K).

  FIG. 6 is a flowchart illustrating control of the first valve unit 71 in the fourth embodiment. The first measurement unit 72 measures the temperature of the superconducting coil 601 and sends data indicating the temperature to the first control unit (step S1). The first controller 73 determines whether or not the temperature of the superconducting coil 601 measured in step S1 is the same as the reference value (step S2).

  When the first control unit 73 determines that the temperature of the superconducting coil 601 is the same as the reference value (Yes in step S2), the process returns to step S1.

  When the first controller 73 determines that the temperature of the superconducting coil 601 is not the same as the reference value (No in step S2), the first controller 73 determines that the temperature of the superconducting coil 601 measured in step S1 is Then, it is determined whether or not it is larger than the reference value (step S3).

  When the first control unit 73 determines that the temperature of the superconducting coil 601 is lower than the reference value (No in step S3), the first control unit 73 controls the first valve unit 71 to perform the first operation. Is closed by a predetermined amount to reduce the flow rate of nitrogen in the liquid state flowing through the flow path 70c and the flow path 70e (step S4). Then, the process returns to step S1.

  When the first control unit 73 determines that the temperature of the superconducting coil 601 is higher than the reference value (Yes in step S3), the first control unit 73 determines whether or not the first valve unit 71 is fully opened. (Step S5).

  When the first control unit 73 determines that the first valve unit 71 is not fully open (No in step S5), the first control unit 73 controls the first valve unit 71 to perform the first operation. The valve portion 71 is opened by a predetermined amount, and the flow rate of liquid nitrogen flowing through the flow path 70c and the flow path 70e is increased (step S6). Then, the process returns to step S1.

  When the first control unit 73 determines that the first valve unit 71 is fully open (Yes in step S5), the first control unit 73 operates a predetermined notification unit (for example, a lamp or a speaker). The person who manages the operation of the air separation device 1d is notified that the temperature of the superconducting coil 601 is higher than the reference value (step S7).

  According to the fourth embodiment, the temperature of the superconducting coil 601 is automatically controlled to the reference value (predetermined value) while the amount of liquid nitrogen supplied to the superconducting coil 601 is minimized. it can.

  Further, according to the fourth embodiment, since the temperature of the superconducting coil 601 is directly measured, the temperature of the superconducting coil 601 can be accurately controlled.

  The fifth embodiment will be described with a focus on differences from the fourth embodiment shown in FIGS. 4 and 5. FIG. 7 is a configuration diagram showing a configuration of an air separation device 1e according to the fifth embodiment. FIG. 8 is a block diagram illustrating a relationship among the second valve unit 74, the second measurement unit 75, and the second control unit 76 in the fifth embodiment. The cooling circuit 7 of the fifth embodiment includes a second valve unit 74, a second measurement unit 75, and a second control unit 76.

  Referring to FIGS. 7 and 8, the second valve unit 74 is an electromagnetic valve that adjusts the flow rate of nitrogen in a liquid state flowing through the flow path 70c (fifth flow path).

  The second measuring unit 75 is a temperature sensor that measures the temperature of nitrogen in a liquid state flowing through the flow path 70e (seventh flow path). A measuring element 751 of the second measuring unit 75 is in contact with liquid nitrogen flowing through the flow path 70e.

  The second control unit 76 includes a CPU, a RAM, and a ROM, and has the same function as the first control unit 73. That is, a predetermined value equal to or lower than the critical temperature of the superconducting material constituting the superconducting coil 601 is set as a reference value. When the temperature measured by the second measuring unit 75 is equal to or lower than the reference value, the second control unit 76 reduces the flow rate of nitrogen in the liquid state supplied to the superconducting coil 601 and measures the second measuring unit 75. When the measured temperature is higher than the reference value, the flow rate of nitrogen in the liquid state supplied to the superconducting coil 601 increases, and the liquid supplied to the superconducting coil 601 when the temperature measured by the second measuring unit 75 is the reference value. The opening / closing amount of the second valve portion 74 is controlled so that the flow rate of nitrogen in the state does not change.

  The reference value (predetermined value) may be a pinpoint value (for example, 77K) or a value having a range (for example, 70K to 77K), similar to the reference value described in the fourth embodiment. .

  The control of the second valve unit 74 is the same as the control of the first valve unit 71 of the fourth embodiment already described with reference to FIG.

  According to the fifth embodiment, when the temperature of the superconducting coil 601 cannot be directly measured for some reason, the temperature of the superconducting coil 601 is estimated indirectly from the temperature of nitrogen in the liquid state flowing through the flow path 70e. Control the temperature.

  According to the fifth embodiment, as in the fourth embodiment, the temperature of the superconducting coil 601 is automatically set to a predetermined value while the amount of nitrogen in the liquid state supplied to the superconducting coil 601 is minimized. Can be controlled.

  The sixth embodiment will be described focusing on differences from the fourth embodiment shown in FIGS. FIG. 9 is a configuration diagram illustrating a configuration of an air separation device 1f according to the sixth embodiment. FIG. 10 is a block diagram illustrating a relationship among the first valve unit 71, the third valve unit 77, the first measurement unit 72, and the first control unit 73 in the sixth embodiment. The cooling circuit 7 according to the sixth embodiment further includes a third valve unit 77 in addition to the first valve unit 71, the first measurement unit 72, and the first control unit 73. The sixth embodiment can cope with the case where the temperature of the superconducting coil 601 is higher than the reference value even if the first valve portion 71 is fully opened.

  Referring to FIG. 9 and FIG. 10, the third valve portion 77 is provided downstream from the connection portion between the flow path 8o (fourth flow path) and the flow path 70c (fifth flow path). This is a solenoid valve that adjusts the flow rate of nitrogen in the liquid state flowing through the passage 8o.

  The first control unit 73 is in a state where the third valve unit 77 is opened (that is, in a state where liquid nitrogen flows through the flow path 8o and is returned to the rectification column 5). The opening / closing amount of the first valve portion 71 described in the above is controlled. The first control unit 73 has a third valve unit when the first valve unit 71 is fully open and the temperature measured by the first measurement unit 73 is larger than a reference value (predetermined value). 77 is controlled to close a predetermined amount. Thereby, the amount of nitrogen in the liquid state flowing through the flow path 8o is reduced, and the amount of nitrogen in the liquid state flowing through the flow path 70c can be increased, so that the superconducting coil 601 can be further cooled.

  FIG. 11 is a flowchart illustrating control of the first valve unit 71 and the third valve unit 77 in the sixth embodiment. About the same process as the flowchart of FIG. 6, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  When the first control unit 73 determines that the first valve unit 71 is fully open (Yes in step S5), the first control unit 73 determines whether or not the third valve unit 77 is fully closed. (Step S8).

  When the first control unit 73 determines that the third valve unit 77 is not fully closed (No in step S8), the first control unit 73 performs control to close the third valve unit 77 by a predetermined amount. (Step S9). Then, the process returns to step S1.

  When the first control unit 73 determines that the third valve unit 77 is fully closed (Yes in step S8), the first control unit 73 operates a predetermined notification unit (for example, a lamp or a speaker). Then, the person who manages the operation of the air separation device 1f is notified that the temperature of the superconducting coil 601 is higher than the reference value (step S7).

  FIG. 12 is a configuration diagram showing a configuration of an air separation device 1g according to the seventh embodiment. FIG. 13 is a block diagram illustrating a relationship among the second valve unit 74, the third valve unit 77, the second measurement unit 75, and the second control unit 76 in the seventh embodiment. The seventh embodiment is characterized in that the third valve portion 77 of the sixth embodiment shown in FIGS. 9 and 10 is provided in the fifth embodiment shown in FIGS. 7 and 8. The seventh embodiment can cope with the case where the temperature of the superconducting coil 601 is higher than the reference value even when the second valve portion 74 is fully opened.

  The second control unit 76 is in a state where the third valve unit 77 is opened (that is, in a state where liquid nitrogen flows through the flow path 8o and is returned to the rectification column 5). The opening / closing amount of the second valve portion 74 described in the above is controlled. The second control unit 76 performs control to close the third valve unit 77 by a predetermined amount when the second valve unit 74 is fully opened and the temperature measured by the second measurement unit 75 is higher than the reference value. To do. Thereby, the amount of nitrogen in the liquid state flowing through the flow path 8o is reduced, and the amount of nitrogen in the liquid state flowing through the flow path 70c can be increased, so that the superconducting coil 601 can be further cooled.

  Regarding the first to seventh embodiments, a commonly applied technique will be described using the air separation device 1a according to the first embodiment shown in FIG. 1 as an example.

  FIG. 14 is a schematic view of the heat-insulated sealed container 9 that houses the superconducting motor 60 and the compression unit 61. A superconducting motor 60 and a compressing unit 61 connected to a rotating shaft 603 are disposed in the heat insulating sealed container 9. The heat insulating sealed container 9 is attached to the wall surface of the rectifying column 5, for example, in the vicinity of the top of the rectifying column 5.

  According to this configuration, the superconducting motor 60 and the compressing unit 61 are accommodated in the heat-insulated airtight container 9 to unitize them. Therefore, the assembly operation of the condensation circuit 6 can be facilitated.

  FIG. 15 is a cross-sectional view showing the configuration of the superconducting motor 60. The superconducting motor 60 includes a rotating shaft 603, a first stator 33a, a second stator 33b, a third stator 33c, a first rotor 34a, a second rotor 34b, and a third rotor 34c. And a fourth rotor 34d. A first stator 33a, a second stator 33b, and a third stator 33c are arranged at intervals along the direction in which the rotation shaft 603 extends from the compression unit 61.

  The first stator 33a is a stator for generating a W phase. The first stator 33 a includes a heat insulating container 35, a bearing 36, a superconducting coil 601, and a partition wall 38.

  The material of the heat insulation container 35 is a nonmagnetic metal material. The heat insulation container 35 has a disk shape. A bearing 36 is disposed at the center of the heat insulating container 35. The bearing 36 holds the rotating shaft 603 rotatably.

  The heat insulating container 35 has a hollow structure. A superconducting coil 601 is disposed in the heat insulating container 35 so as to surround the bearing 36. The superconducting coil 601 is wound around a magnetic core (not shown) fixed in the heat insulating container 35. The magnetic core and the superconducting coil 601 constitute a superconducting magnet. The inside of the heat insulating container 35 is filled with the refrigerant supplied from the rectification tower 5, that is, nitrogen in a gaseous state (boil-off gas). In the second embodiment to the seventh embodiment, the inside of the heat insulating container 35 is filled with nitrogen in a liquid state generated in the condensation circuit 6.

  The heat insulating container 35 has an annular through hole at a location facing the superconducting coil 601. The through hole is closed by the partition wall 38. The partition 38 has a heat insulating property, a non-magnetic property and an insulating property, or a heat insulating property, a non-magnetic property and a high resistance property. The material of the partition wall 38 is, for example, hard glass, ceramics, or hard plastic.

  The reason why the partition wall 38 has a heat insulating property is to insulate the inside of the heat insulating container 35 filled with the refrigerant from the outside of the heat insulating container 35 which is a low-temperature atmosphere or a vacuum. The reason why the partition wall 38 is non-magnetic is to magnetically couple the superconducting coil 601 and a magnetic core (not shown) around which the superconducting coil 601 is wound to the permanent magnets 41 and 43. The reason why the partition 38 has an insulating property or a high resistance is to prevent an eddy current from being generated in the partition 38. This is because the partition wall 38 generates heat if an eddy current is generated in the partition wall 38 due to the fluctuating magnetic field generated due to the magnetic coupling.

  The second stator 33b is a stator for generating a V phase, and the third stator 33c is a stator for generating a U phase. The configurations of the second stator 33b and the third stator 33c are the same as the configuration of the first stator 33a, and thus the description thereof is omitted.

  The configuration of the superconducting coil 601 provided in each of the first stator 33a, the second stator 33b, and the third stator 33c is, for example, a coil provided in the stator disclosed in Japanese Patent Application Laid-Open No. 2014-54092. The same configuration can be adopted.

  A first rotor 34a, a second rotor 34b, a third rotor 34c, and a fourth rotor 34d are arranged at intervals along the direction in which the rotation shaft 603 extends from the compression unit 61. Yes. The first stator 33a is sandwiched between the first rotor 34a and the second rotor 34b at a predetermined interval. The second stator 33b is sandwiched between the second rotor 34b and the third rotor 34c at a predetermined interval. The third stator 33c is sandwiched between the third rotor 34c and the fourth rotor 34d at a predetermined interval.

  The rotation shaft 603 is fixed to the center of each of the first rotor 34a, the second rotor 34b, the third rotor 34c, and the fourth rotor 34d, and the first rotor 34a, As the second rotor 34b, the third rotor 34c, and the fourth rotor 34d rotate, the rotation shaft 603 rotates.

  The first rotor 34 a includes a magnetic material yoke 40 and a permanent magnet 41. The magnetic material yoke 40 has a disk shape. A permanent magnet 41 is disposed on the surface of the magnetic material yoke 40 facing the first stator 33a. The permanent magnet 41 surrounds the rotating shaft 603 and is disposed to face the partition wall 38 and the superconducting coil 601 provided in the first stator 33a.

  The second rotor 34 b includes a structural member 42 and a permanent magnet 43. The structural member 42 has a disk shape. A permanent magnet 43 is disposed on the peripheral surface of the structural member 42. The permanent magnet 43 surrounds the rotating shaft 603 and faces the partition wall 38 and the superconducting coil 601 provided in the first stator 33a and the partition wall 38 and the superconducting coil 601 provided in the second stator 33b. Has been placed.

  The third rotor 34c has the same configuration as the second rotor 34b. The permanent magnet 43 of the third rotor 34c surrounds the rotating shaft 603, and includes the partition wall 38 and the superconducting coil 601 provided in the second stator 33b, and the partition wall 38 provided in the third stator 33c and It is arranged to face the superconducting coil 601.

  The fourth rotor 34d has the same configuration as the first rotor 34a. The permanent magnet 41 of the fourth rotor 34d surrounds the rotating shaft 603 and is disposed to face the partition wall 38 and the superconducting coil 601 provided in the third stator 33c.

  The permanent magnets 41 and 43 are, for example, rare earth permanent magnets. Since the rare earth-based permanent magnet has a strong coercive force, the superconducting motor 60 having a high torque density can be realized in the first to seventh embodiments.

  In recent years, research has been conducted to realize a strong permanent magnet by confining magnetic flux inside the bulk oxide superconductor by using the pinning effect of the bulk oxide superconductor. The permanent magnet may be a superconducting bulk magnet. Since the superconducting bulk magnet has a higher coercive force than the conventional permanent magnet, a highly efficient superconducting motor 60 can be realized by replacing this with a conventional permanent magnet.

  A first tube portion 44a, a second tube portion 44b, and a third tube portion 44c are arranged along the direction of the rotation shaft 603. The 1st pipe part 44a connects the heat insulation container 35 of the 1st stator 33a, and the heat insulation container 35 of the 2nd stator 33b. The inside of the heat insulation container 35 of the first stator 33a and the inside of the heat insulation container 35 of the second stator 33b communicate with each other through the first pipe portion 44a. The second pipe portion 44b connects the heat insulating container 35 of the second stator 33b and the heat insulating container 35 of the third stator 33c. The inside of the heat insulating container 35 of the second stator 33b and the inside of the heat insulating container 35 of the third stator 33c communicate with each other through the second pipe portion 44b.

  One end of the third tube portion 44c is connected to the third stator 33c. The flow path 70a enters the third tube portion 44c from the other end of the third tube portion 44c, and the inside of the heat insulating container 35 of the third stator 33c, the second tube portion 44b, and the second stator 33b. Are passed through the inside of the heat insulating container 35, the first pipe portion 44a, and the heat insulating container 35 of the first stator 33a. The flow path 70b is passed from the other end of the third tube portion 44c to the third tube portion 44c. Nitrogen (refrigerant) in a gaseous state supplied from the rectification tower 5 passes through the flow path 70a and enters the heat insulating containers 35 of the first stator 33a, the second stator 33b, and the third stator 33c. Sent. The refrigerant sent to these heat insulation containers 35 returns to the flow path 8i shown in FIG. 1 through the flow path 70b. Thus, the refrigerant circulates between the condensation circuit 6 and the heat insulating containers 35 of the first stator 33a, the second stator 33b, and the third stator 33c.

  Since the first tube portion 44a, the second tube portion 44b, and the third tube portion 44c are required to be airtight, they are usually made of metal. The superconducting motor 60 is assembled in a normal temperature environment and used in an environment below a critical temperature. For this reason, in order to absorb the thermal deformation of the 1st pipe part 44a, the 2nd pipe part 44b, and the 3rd pipe part 44c, these pipe parts have a bellows structure.

1a, 1b, 1c, 1d, 1e, 1f, 1g Air separation device 5 Rectifying tower 6 Condensing circuit 7 Cooling circuit 8i Flow path (specific example of the first flow path)
8o channel (specific example of the fourth channel)
60 Superconducting motor 61 Compression unit 62 Heat exchange unit 63 Expansion unit 70a Flow path (specific example of second flow path)
70b channel (specific example of the third channel)
70c channel (specific example of the fifth channel)
70d channel (specific example of sixth channel)
70e channel (specific example of seventh channel)
71 1st valve part 72 1st measurement part 73 1st control part 74 2nd valve part 75 2nd measurement part 76 2nd control part 77 3rd valve part 601 Superconducting coil (specific of superconducting magnet) Example)

Claims (7)

A rectifying column that cryogenically separates the raw material air in the liquid state to generate nitrogen in the gaseous state;
Among the nitrogen in the gaseous state taken out from the rectification column, a part of the nitrogen is supplied, a condensation circuit for changing the supplied nitrogen from a gaseous state to a liquid state and returning the nitrogen to the rectification column,
A cooling circuit,
The condensing circuit is
A superconducting motor including a superconducting magnet composed of a superconducting material having a critical temperature higher than the boiling point of liquid nitrogen;
A compression unit that is driven by the superconducting motor and compresses nitrogen in a gas state flowing through the condensing circuit;
The cooling circuit uses the nitrogen in the liquid state through said condensing circuit, cooling the superconducting magnet below the critical temperature,
The condensing circuit is
An inflating part for changing nitrogen from a gaseous state to a liquid state by inflating nitrogen in a gaseous state compressed by the compressing part;
A fourth flow path for connecting the expansion section and the rectification column and guiding nitrogen in a liquid state to the rectification column,
The cooling circuit is
A fifth flow path connected to the fourth flow path and supplying a part of the liquid nitrogen flowing through the fourth flow path to the superconducting magnet;
An air separation device , comprising: a seventh channel connected to the rectification column and guiding nitrogen in a liquid state supplied to the superconducting magnet by the fifth channel to the rectification column . The cooling circuit is
A first valve section for adjusting a flow rate of nitrogen in a liquid state flowing through the fifth flow path or the seventh flow path;
A first measuring unit for measuring the temperature of the superconducting magnet;
When the temperature measured by the first measurement unit is smaller than a predetermined value equal to or lower than the critical temperature, the flow rate of nitrogen in a liquid state supplied to the superconducting magnet decreases, and the first measurement unit When the measured temperature is greater than the predetermined value, the flow rate of liquid nitrogen supplied to the superconducting magnet increases, and the temperature measured by the first measurement unit is the predetermined value. The air separation according to claim 1 , further comprising: a first control unit that controls an opening / closing amount of the first valve unit so that a flow rate of liquid nitrogen supplied to the superconducting magnet does not change. apparatus. The cooling circuit is
A second valve portion for adjusting a flow rate of nitrogen in a liquid state flowing through the fifth flow path;
A second measuring unit for measuring a temperature of nitrogen in a liquid state flowing through the seventh flow path;
When the temperature measured by the second measurement unit is smaller than a predetermined value not more than the critical temperature, the flow rate of liquid nitrogen supplied to the superconducting magnet decreases, and the second measurement unit When the measured temperature is greater than the predetermined value, the flow rate of liquid nitrogen supplied to the superconducting magnet is increased, and the temperature measured by the second measurement unit is equal to the predetermined value. The air separation according to claim 1 , further comprising: a second control unit that controls an opening / closing amount of the second valve unit so that a flow rate of liquid nitrogen supplied to the superconducting magnet does not change. apparatus. The cooling circuit is provided downstream of a connection portion between the fourth flow path and the fifth flow path, and a third valve portion that adjusts a flow rate of liquid nitrogen flowing through the fourth flow path. Further comprising
The first control unit controls the opening / closing amount of the first valve unit with the third valve unit opened, and the first valve unit is fully opened with the first valve unit opened. The air separation device according to claim 2 , wherein when the temperature measured by one measuring unit is larger than the predetermined value, the third valve unit is controlled to be closed by a predetermined amount. The cooling circuit is provided downstream of a connection portion between the fourth flow path and the fifth flow path, and a third valve portion that adjusts a flow rate of liquid nitrogen flowing through the fourth flow path. Further comprising
The second control unit controls the opening / closing amount of the second valve unit with the third valve unit opened, and the second valve unit is fully opened with the second valve unit opened fully. when the temperature measured by the second measurement section is greater than the predetermined value, the air separation unit according to claim 3, a predetermined amount close control the third valve portion. The rectification column is a cryogenic separation of liquid source air to produce liquid oxygen.
The condensing circuit cools the gaseous nitrogen by causing heat exchange between the liquid oxygen extracted from the rectification column and the gaseous nitrogen compressed by the compression unit, and the liquid state The air separation device according to any one of claims 1 to 5 , further comprising a heat exchanging unit that converts the oxygen of the gas into a gaseous state. The superconducting motor and the air separation unit as claimed in any one of claims 1 to 6, further comprising a heat insulating hermetic container for accommodating the compressing unit.

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