JPS6032099B2 - Supercooled liquefied gas supply equipment - Google Patents

Description

Detailed Description of the Invention The present invention provides a supercooled liquefied gas supply device that supercools a liquefied gas such as liquid helium to below the saturation temperature and continuously supplies the supercooled liquefied gas to an object to be cooled, such as a superconducting coil. It is related to.

FIG. 1 is a system block diagram showing a schematic configuration of a subcooled liquefied gas supply device.

In the figure, 1 is a liquefied gas tank, and when this liquefied gas tank 1 is filled with liquefied gas, a liquid phase part la and a gas phase part lb are formed in the tank. 2A is a supercooler, which is provided in the space of the gas phase section lb.

There are two flow paths in the supercooler 2A, and the fluids in the flow paths exchange heat with each other. Reference numeral 3 denotes a liquefied gas pressurizing system line, and this liquefied gas pressurizing system 3 leads the liquefied gas in the liquefied gas tank 1 to the outside of the tank while maintaining the pressure inside the tank through a subcooler 2A. Liquefied gas pressurization system 3
The open end in the tank is configured to be below the liquid level of the liquefied gas.

4 is a liquefied gas pressure reduction system, and this liquefied gas pressure reduction system 41 is provided with a pressure reduction device 5 and a gas-liquid separator 6, which reduces the pressure of the liquefied gas in the liquefied gas tank 1 to a predetermined temperature, and lowers the pressure to a low temperature. After passing through the supercooler 2A, the liquefied gas is led out of the tank through the reduced pressure gas system 8 of the condenser 7A.

Reference numeral 9 denotes a pressure reduction system pressure control valve for controlling the pressure of the gas discharged through the liquefied gas pipe 10' through the liquefied gas pressure reduction system 4, and a pressure reduction vessel 11 is provided to compensate for the operating characteristics of this pressure control valve 9.

Reference numeral 13 denotes a gas pressurizing device for compressing and purifying the gas discharged from the liquefied gas tank 1 by the exhaust device 12 and returning it to the liquefied gas tank 1 again. A protection tank 14 is provided on the side to keep the pressure on the suction side of the gas pressurization device 13 constant.

Further, the gas returned to the liquefied gas tank 1 by the gas pressurizing device 13 is precooled by the exhaust gas from the liquefied gas tank 1 in the reliquefaction system 15 of the condenser 7A, and is partially liquefied. Reference numeral 16 indicates a pressure regulating valve for discharging surplus gas in the system to adjust the pressure of the gas supplied to the reliquefaction system 15.

A case in which supercooled liquefied gas is obtained in the above configuration will be specifically described.

In the following, a case will be described in which liquid helium is used as the liquefied gas. First, from the liquefied gas supply tank 17 to the liquefied gas tank 1 through the supply transfer pipe 18, a pressure of 1
．． 2tm temperature 4. Inject liquid helium into the tank.

When supplying supercooled liquid helium to the object to be cooled 19A, 1. After t
When a gas pressure of m is applied, the liquefied gas is led out of the tank via the liquefied gas pressurization system 3 and the liquefied gas depressurization system 4. In this derivation process, the liquid helium flowing through the liquefied gas decompression system 4 passes through the decompression device 5 and flows into the supercooler 2A,
It evaporates here. For example, in the pressure reducing device 5, 0.1at
When the pressure is reduced to m, the temperature drops to 2.5K. The liquid helium flowing through the liquefied gas pressurization system 3 enters the supercooler 2A, exchanges heat with the liquid helium flowing through the liquefied gas depressurization system 4, and is supercooled to about 100% at 1.2 tm. 20 to the object to be cooled 19A. In the liquefied gas decompression system 4 in the above case, for example, 30
When liquid helium is supplied to the object to be cooled 19A at the rate of 9.1 times per hour, the liquid helium evaporates in the supercooler 2A. The helium gas evaporated in the supercooler 2A enters the decompression system 8 of the condenser 7A, leaving a liquid phase in the gas-liquid separator 6, and cools the pressurized gas entering the reliquefaction system 15 by heat exchange. Pressure 1.2tm, temperature 4. During the cycle, 4.9 so/h of helium, which corresponds to 10% of the decompression system flow rate, is condensed and liquefied. For this reason, 46% of the gas that cannot be liquefied in the reliquefaction system is released into the atmosphere from the pressure regulating valve 16. Next, a method of cooling the object to be cooled 19A using supercooled liquid helium will be explained.

In the following, a superconducting rotor as the object to be cooled 19A will be explained. The object to be cooled 19A is a superconducting coil 21 and a power lead 22 that supplies current to the superconducting coil.
, a torque tube 23 that transmits rotational force, an electromagnetic damper 24 that relieves electromagnetic force, a helium supply V port 25 that introduces liquid helium, a normal temperature gas discharge port 26 that discharges helium gas that has cooled the power lead, and a torque tube. It is composed of a low-temperature discharge port 27 that discharges helium gas that has cooled the electromagnetic damper.

To cool the object to be cooled 19A, first, the supercooled liquid helium that enters from the helium supply port 25 through the supercooled liquid transfer pipe 20 is subjected to centrifugal force due to rotation within the object to be cooled 19A.
The superconducting coil 21 flows into the superconducting coil 21 portion, becomes immersed, and is cooled. If there is a heat load on the superconducting coil 21 part,
The temperature of the supercooled liquid helium increases, and after reaching the saturation temperature, it evaporates and becomes a gas. A part of the supercooled liquid helium cools the power lead 22 and is discharged into the atmosphere from the normal temperature gas outlet 26. Further, other gases that do not flow to the power lead 22 cool the torque tube 23 and the electromagnetic damper in the low-temperature portion, and then are discharged into the atmosphere from the low-temperature gas outlet 27 in a low-temperature state. As mentioned above, the IJum evaporated in the reduced pressure gas system 4 of the supercooler 2A is pressurized and returns to the reliquefaction system 15, where about 1/2 is condensed and liquefied in the supercooler, but the remaining gas is liquefied. was released into the atmosphere from the pressure regulating valve 16 without being released.

In addition, most of the helium evaporated in the cooled body 19A is released into the atmosphere from the low temperature gas exhaust port at a low temperature of 30 to 10 cm, and a portion is also released into the atmosphere from the room temperature gas exhaust port. Ta. This has the disadvantage that the amount of helium gas consumed increases, making continuous operation difficult and increasing operating costs.Also, since freezing of low-temperature gas is not regenerated, the gas liquefaction equipment required to supply liquid helium becomes large. Ta. This invention was made in order to eliminate the above-mentioned drawbacks, and aims to provide a supercooled liquefied gas supply device that consumes almost no helium gas and can be configured with a gas liquefier having a small capacity. be.

The present invention will be explained below with reference to the drawings.

FIG. 2 is a system block diagram showing the configuration of an embodiment of the supercooled liquefied gas supply system of the present invention.

In the figure, reference numeral 1 denotes a liquefied gas tank, which includes a supercooled liquid transfer pipe 20, a pressure reducing device 5, a supercooler 2A, a gas-liquid gas tank, and a pressure reducing device 5, a supercooler 2A, and a supercooled liquid transfer pipe 20 to combine the supercooled liquefied gas through the supercooler 2A and into the object to be cooled 19A. A reduced pressure gas pipe 10 for sending evaporated gas to the exhaust device 12 through the separator 6 and the condenser 7A, and a pressurized gas introduction pipe 116 for introducing pressurized gas from the gas pressurization device 13 for reliquefaction. , and a replenishment liquid transfer pipe 18 for transferring liquefied gas from the liquefied gas replenishment tank 17.

28A is a gas recovery device, which includes a gas compressor 29, a low-pressure gas container 30, a first expander 31, a second expander 32, and a first heat exchanger 33 and a second heat exchanger 34 from room temperature to low temperature. ,
Third heat exchanger 35, fourth heat exchanger 36, fifth heat exchanger 3
It consists of five heat exchanger groups (No. 7) and piping connecting them.

Here, the system connected to the gas discharge pipe 38 of the gas compressor 29 is called a high pressure system, and the system connected to the gas suction pipe 39 is called a low pressure system. The gas recovery device 28A includes a room-temperature gas recovery pipe a41 for recovering gas from the low-pressure gas container 301 from the room-temperature gas outlet 26 of the object to be cooled 19A via the gas recovery valve 40, and a gas recovery system from the gas pressurizing device 13. Room temperature gas recovery piping b that recovers gas to the low pressure gas container 30 via the pressure control valve 42
43, low temperature gas is supplied to the third heat exchanger 35, the second heat exchanger 34, or the first heat exchanger 33 from the low temperature gas discharge port 27 of the object to be cooled 19A via the low temperature valve a44, the low temperature valve b45, or the low temperature valve c46. A low-temperature gas recovery pipe 47 for recovering gas is connected to each.

In addition, there are a branch pipe a144, a branch pipe b145, and a branch pipe c146 at the low-pressure system inlet of the heat exchanger group, and the object to be cooled 19
A low-temperature exhaust gas is introduced. The low-temperature high-pressure gas that has passed through the fifth heat exchanger 37 is
Thomson) Liquefied gas supply tank 1 through high pressure pipe 48
The liquid reaches the J-T valve (Joule-Thomson) 49 in 7, undergoes isenthalpic expansion, and a part of the liquid is liquefied. The low-temperature, low-pressure gas that did not liquefy during this expansion process is stored in the J-T low-pressure pipe 50.
and returns to the low pressure side of the fifth heat exchanger 37 via the low temperature valve d51. Next, a series of operations of the supercooled liquefied gas supply device having the above-described configuration will be explained.

In the following, a case will be explained in which liquid helium is used as the liquefied gas. First, gas recovery device 28A
The helium gas in the low-pressure gas container 30 is sucked into the gas compressor 29 from the gas suction pipe 39, compressed to about 1 tm, and enters the high-pressure system of the first heat exchanger 33 from the gas discharge pipe 38.

Here, it is cooled by the gas in the low pressure system and becomes about 13011, reaches the outlet of the first heat exchanger 34, a part of which enters the first expander 31, expands, and becomes about 8 low-temperature low-pressure gases. 2 Return to the low pressure system inlet of the heat exchanger 34. The gas separated at the high pressure system outlet of the first heat exchanger 34 is transferred to the second heat exchanger 34.
It exchanges heat with the gas flowing through the low-pressure system of the third heat exchanger 35 and is cooled down to about 2 degrees, reaching the outlet of the third heat exchanger 35. A part of it enters the second expander 32 and expands to about It becomes one shoe of low-temperature, low-pressure gas and returns to the low-pressure system inlet of the fourth heat exchanger 36. The gas separated at the high-pressure system outlet of the third heat exchanger 35 exchanges heat with the gas flowing through the low-pressure system of the fourth heat exchanger 36 and the fifth heat exchanger 37, and is cooled to a certain temperature. It reaches the outlet of the exchanger 37, flows through the J-T high pressure pipe 48 into the J-T valve 49 in the liquefied gas replenishment tank 17, expands, and is partially liquefied and stored in the liquefied gas replenishment tank 17. The remaining gas that was not liquefied in step 17 passes through the low-temperature gas recovery pipe 50 and returns to the low-pressure system of the J-T heat exchanger 37 via the low-temperature valve c51, cooling the gas in the high-pressure system. The gas flows through the low-pressure system of the heat exchanger 36, the third heat exchanger 35, the second heat exchanger 34, and the first heat exchanger 33, reaches room temperature, and returns to the gas suction pipe 39.

The liquid helium stored in the liquefied gas supply tank 17 is
The liquefied gas tank 1 is filled with the replenishing liquid through the replenishment liquid transfer pipe 18.

Supercooled liquid helium is transferred from the liquefied gas tank 1 to the object to be cooled 19A.
The configuration for connecting to is the same as that shown in FIG. That is, when a gas pressure of, for example, 1.2 tm is applied to the gas phase portion lb of the liquefied gas tank 1, the liquid helium flowing through the liquefied gas pressure reduction system flows through the pressure reduction device 5 into the supercooler 2A, where the pressure is, for example, 0.2 tm.
2. The pressure is reduced to 1 atm. The temperature drops until the song. The liquid helium flowing into the liquefied gas pressurization system enters the supercooler 2A, exchanges heat with the liquid helium flowing through the liquefied gas depressurization system 4, and is supercooled to about 1 trillion at 1.2 tm' before being transferred to the low-temperature supply pipe. 20 to be cooled 19A. Cooling of the object to be cooled 19A by supercooled helium is the same as the explanation in FIG. The gas passes through the room temperature gas recovery pipe a41 from the exhaust port 26 and is recovered as room temperature exhaust gas through the gas recovery valve 40 into the low pressure gas container 30'.

In addition, the remaining gas that does not flow to the power lead 22 cools the torque tube 23 and electromagnetic damper 24 in the low-temperature portion, and then passes through the low-temperature gas exhaust port 27 through the low-temperature gas recovery pipe 46 in a low-temperature state, and is heated by the gas recovery device 28A. It is recovered to the low pressure system of exchanger group 35, 34 or 33. At this time, the temperature of the low-temperature recovered gas is the inlet temperature of the second expander, for example, 2
When the temperature is lower than the arc, the water flows to the low pressure system inlet of the third heat exchanger 35. When the temperature is from 2 arc to 8 blood, it flows to the low pressure system inlet of the second heat exchanger 34, and when the temperature is from 8 to 13, the water flows to the low pressure system inlet of the third heat exchanger 35. 1 to the low pressure system inlet of the heat exchanger 33. In this way, the object to be cooled 1
Gas recovery device 2 depending on the temperature of the low temperature recovery gas from 9A.
If the low-temperature valve 44, 45 or 46 which is recovered to the low pressure system of the 8A heat exchanger 35, 34 or 33 is opened,
Freezing of low-temperature gas can be efficiently recovered. On the other hand, the helium gas evaporated in the supercooler 2A enters the decompression gas system 8 of the condenser 7A and "cools the newly incoming gas in the reliquefaction system 15 in order to increase the pressure in the liquefied gas tank 1. After that, the reduced pressure gas piping 10, the reduced pressure system pressure control valve 9
and reaches the exhaust device 12.

The gas discharged from the exhaust device 12 is collected in the pressure holding tank 14, compressed and purified in the gas pressurization device 13, flows into the reliquefaction system 15 of the condenser 7A, exchanges heat with the gas in the decompression gas system 8, and depressurizes the gas. Approximately 50% of the gas flow rate is condensed and liquefied. The remaining gas that has not been liquefied in the pressurized gas introduction pipe 116 passes through the gas recovery system pressure control valve 42, flows through the normal temperature gas recovery pipe b43, and is collected in the three low pressure gas containers. Therefore, the pressure within the liquefied gas tank 1 is automatically controlled by the gas recovery pressure control valve 42, and fluctuations in the operating temperature of the supercooler 2A are prevented. In the above embodiments, liquid helium was particularly taken up for explanation, but it goes without saying that the present invention can also be applied to other liquefied gases such as hydrogen, neon, nitrogen, argon, and LNG.

Furthermore, in the above embodiment, depending on the temperature of the low-temperature recovery gas from the object to be cooled 19A, the heat exchanger 35 of the gas recovery device 28A,
Low temperature valve a44b4 connected to 34 or 33 low pressure system
5 or open the low temperature valve C44,
If the temperature of the low-temperature recovery gas from the object to be cooled 19A is known in advance, it is connected to a low-pressure system suitable for that temperature, for example, in the case of 50%, it is connected to the low-pressure system inlet of the second heat exchanger 34. It is only necessary to provide a branch pipe 145 and a low temperature valve b45.

As described above, according to the present invention, a gas recovery device is provided to recover the gas generated by cooling the object to be cooled and the gas that has not been liquefied in the condenser, so that the gas can be released outside the system. There is no need to consume a large amount of gas for liquefaction.

In addition, if the gas led to the heat exchanger is cooled by the low-temperature exhaust gas from the object to be cooled, the gas liquefaction capacity will increase and the efficiency of the system will improve. can be realized.

[Brief explanation of the drawing]

FIG. 1 is a system block diagram showing the structure of a conventional supercooled liquefied gas supply apparatus, and FIG. 2 is a system block diagram showing the structure of an embodiment of the supercooled liquefied gas supply apparatus according to the present invention. In the figure, 2A is a supercooler, 8 is a reduced pressure gas system, and 13
19A is a gas pressurization device, 19A is an object to be cooled, 20 is a supercooled liquid transfer pipe, 26 is a normal temperature gas outlet, 27 is a low temperature gas outlet,
28A is a gas recovery device, 33 is a first heat exchanger, 34 is a second heat exchanger, 35 is a third heat exchanger, 39 is a gas suction pipe,
41 is a normal temperature gas recovery pipe a, 43 is a normal temperature gas recovery pipe,
44 is a low temperature valve a, a145 is a branch pipe b, and 146 is a branch pipe c. Note that the same reference numerals in the figures indicate the same or corresponding parts.
Figure 1 Figure 2

Claims (1)

[Claims] 1. A supercooler that vaporizes a part of the liquefied gas and supercools the other liquefied gas, and an object to be cooled that is cooled by the supercooled liquefied gas from the supercooler. and condensation, in which the liquefied gas used to supercool other liquefied gases is pressurized in the supercooler, and the pressurized gas is cooled and condensed by the gas vaporized in the supercooler. The supercooled liquefied gas supply device is equipped with a gas recovery device that recovers gas generated by cooling the object to be cooled and gas that is not liquefied in the condenser through a pressure control valve. A supercooled liquefied gas supply device characterized by: 2. The gas recovery device is equipped with a pressurizer that pressurizes gases other than low-temperature gases generated by cooling the object to be cooled and gases that have not been liquefied by the condenser, and a pressurizer that pressurizes the pressurized gas from this pressurizer as described above. It consists of a heat exchanger that cools the gas generated by cooling the object to be cooled using low-temperature gas, and a Juul-Thomson (J-T) valve that performs isenthalpic expansion and liquefaction of the gas from the heat exchanger. The supercooled liquefied gas supply device according to claim 1, characterized in that: 3. Claim No. 3 characterized in that the low-temperature gas from the object to be cooled and the non-liquefied gas are sent to the heat exchanger of the gas recovery device by the Juul-Thompson valve, and the pressurizer is cooled together with the low-temperature gas. The supercooled liquefied gas supply device according to item 2. 4. Supercooled liquefied gas supply according to claim 2, characterized in that the heat exchanger is of a multi-stage type and low-temperature gas having a temperature lower than the gas temperature at the outlet of each stage is introduced into each stage. Device.