JP3148012B2 - Refrigeration equipment for superconducting magnetic levitation vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system for a superconducting magnetic levitation vehicle.

[0002]

2. Description of the Related Art In a helium liquefaction circuit, helium gas as a working medium is precooled by a multi-stage heat exchanger or a cold head of another refrigerator, and then expanded and liquefied by a JT valve. However, if impurities such as water and other gases are contained in helium gas, the freezing point of the impurities is higher than that of helium, so the impurities are also cooled and solidified during precooling or liquefaction of the helium gas. This causes clogging of the piping in the helium liquefaction circuit. Therefore, in a refrigeration circuit used in a cryogenic region such as a helium liquefaction circuit,
It is necessary to sufficiently remove impurities in the working gas and to keep the working gas highly pure at all times.

Therefore, a gas purifier 100 as shown in FIG. 5 is sometimes inserted in a helium liquefaction circuit. Here, in the housing 101, a pair of holding plates with filters 102 and 103 are disposed in a sealed state on the housing 101, and a particulate gas purification filler 104 having a catalytic / adsorbing action is held between the two. Is done. Then, when the gas to be treated passes through the filler 104 from the holding plate 102 side and flows out from the holding plate 103 side, it is purified to become a high-purity gas.

Meanwhile, the above-described helium liquefaction circuit is used to cool the superconducting magnet of the superconducting magnetic levitation vehicle. A superconducting magnetic levitation vehicle travels by using the repulsion / attractive force of a ground coil and a superconducting magnet, and a force acts on the ground coil and the superconducting magnet so as to maintain a constant distance from each other. . Therefore, if the XYZ alignment of the ground side coil in the three directions is low, the superconducting magnet also moves so as to maintain a constant interval according to the position of the ground side coil in the XYZ direction, so that the superconducting magnet receives large vibration.

[0005] When such a large vibration is received, the vibration and acceleration reach not only the helium liquefaction circuit but also the gas purification device. As a result, the filler filled in the gas purifier moves, and the packing density changes, so that voids are generated in the gas purifier. Then, abrasion between the fillers and between the filler and the inner wall surface of the housing of the gas purification apparatus, mutual destruction due to collision, and the like occur, and a part of the filler is powdered, and helium gas and the downstream side of the gas purification apparatus. There was a risk of spills.

[0006]

Accordingly, an object of the present invention is to improve the performance of a refrigeration system for a superconducting magnetic levitation vehicle by enhancing the vibration resistance of a gas purification apparatus.

[0007]

Configuration of the Invention

[0008]

The technical means of the present invention taken to solve the above-mentioned technical problem of the present invention includes a base connected to a superconducting magnetic levitation vehicle, and a vibration damping mechanism provided on the base. A cryogenic refrigerator disposed on a base and having a cold head, a cryogenic refrigerator disposed on a base, a refrigerator, a gas purification device, and a refrigeration unit thermally coupled to the cold head;
A helium liquefaction circuit for generating liquid helium for cooling the superconducting magnet, comprising a JT valve and a countercurrent heat exchanger, constitutes a refrigeration system for a superconducting magnetically levitated vehicle. It is composed of the filler filled in between, and a biasing means for biasing the movable holding plate toward the fixed holding plate to press the filler, and is arranged on the base.

[0009]

According to the above-mentioned technical means of the present invention, the large vibration generated by the superconducting magnet is attenuated by the vibration damping mechanism, and the vibration transmitted to the base is reduced. On the other hand, in the gas purification device in the liquefied helium circuit connected to the cold head of the cryogenic refrigerator disposed on the base, the filler is pressed by the urging means, and the internal movement amount is extremely small.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the technical means of the present invention will be described below with reference to the accompanying drawings.

Referring to FIG. 1, a superconducting magnetic levitation vehicle 10 mainly includes a vehicle body 11 and a mechanism 12, both of which are integrally connected and connected at a portion (not shown) via a vibration damping mechanism (not shown). A passenger seat 13 and a door 14 for moving to and from another vehicle are arranged in the body 11. The superconducting magnets 32 disposed on both sides of the mechanism section 12 face the ground-side coils 16 disposed on the track 15.

The mechanism section 12 will be described in detail in FIG. 2. However, since the mechanism section 12 is symmetrical in FIG. 1, only the left side thereof will be described. A superconducting magnet 32 is indirectly connected to the base 30 via a vibration damping mechanism 31 such as a damper. That is, the superconducting magnet 32 is accommodated below a liquid helium container 34 disposed in the cryostat 33, and the outer wall of the cryostat 33 and the base 30 are connected via the vibration damping mechanism 31. Above the liquid helium container 34, a discharge port 36 and a return port 37 of a helium liquefaction circuit 35 are opened. In the helium liquefaction circuit 35, downstream of the discharge side of the gas compressor 44, the first gas purification device 38, the high pressure side of the first countercurrent heat exchanger 39,
Refrigeration unit 40, second gas purification device 41, high pressure side of second countercurrent heat exchanger 42, second refrigeration unit 43, third countercurrent heat exchanger 45
High-pressure side, the third refrigeration section 46, the third gas purifier 47, the high-pressure side of the fourth countercurrent heat exchanger 48 and the JT (Jule-
Thomson) valves 49 are sequentially connected to the discharge port 36. On the other hand, downstream of the return port 37, the low pressure side of the fourth countercurrent heat exchanger 48, the low pressure side of the third countercurrent heat exchanger 45,
Low pressure side of countercurrent heat exchanger 42 and first countercurrent heat exchanger 39
Are sequentially connected to the suction side of the gas compressor 44. Then, the first, second, and third refrigeration units 40, 43,
Reference numerals 46 denote first and second cryogenic refrigerators (for example, refrigerators that can reach up to about several K, such as reverse Stirling refrigerators) 50.
It is thermally coupled to the second and third cold heads 51, 52, 53. The first, second and third gas purifiers 38,
Both 41 and 47 are arranged on the base 30.

Here, the liquid helium container 34 is disposed in the cryostat 33 as described above, but the portion of the helium liquefaction circuit 35 except for the normal temperature part (the gas compressor 44 and the first gas purifier 38) is connected to the liquid helium container 34. The first, second, and third cold heads 51, 52, and 53 of the low-temperature refrigerator 50 are also accommodated in the cryostat 33, and the cryostat 3 is provided.
The inside of 3 is kept in a vacuum state. The cryostat 33 is largely divided into a first portion 54 and a second portion 55, and the two are connected by a flexible tube portion 56. The flexible tube section 56 does not directly transmit the vibration of the first section 54 to the second section 55.

Next, the first, second and third gas purifiers 3
The configurations of 8, 41, and 47 will be described. The difference between them is only the size, and the configurations are all the same. A gas inlet 61 and a gas outlet 62 are formed at both ends of the cylindrical housing 60, and a chemical adsorbent 63 and a physical adsorbent 64 as fillers are formed therein.
Is stored.

In the housing 60, each adsorbent 6
The movable holding plate 65 and the fixed holding plate 6
The movable holding plate 65 is urged toward the fixed holding plate 66 by a spring 67 as an urging means. That is, the movable holding plate 65 is slidable in the axial direction within the housing 60, and the fixed holding plate 66 is fixed to the inner wall of the housing 60 at the peripheral edge thereof by welding or the like. Here, each of the holding plates 65 and 66 is attached to each of the adsorbents 6.
From the side adjacent to the glass wool layers 65a, 65
6a, stainless steel metal filters 65b and 66b and metallic holding plates 65c and 66c. Further, the metal filters 65b, 66b and the metal holding plate 65
c and 66c are welded and fixed at the periphery of the metal filters 65b and 66b. In addition, since the trapping rate of particles in the metal filters 65b and 66b is low, the trapping rate of particles is increased by the glass wool layers 65a and 66a.

The gas inlet 61 and the gas outlet 62 are connected to the helium liquefaction circuit 35 via a self-sealing coupling 70 as shown in FIG. A primary side 71 of a self-sealing coupling 70 is connected to the gas inlet 61 (gas outlet 62), and the helium liquefaction circuit 35
The secondary side 72 of the self-sealing coupling 70
Is connected. Now, in the state shown in FIG. 4, the primary side 71 and the secondary side 72 are connected, and the gas inlet 61
The (gas outlet 62) communicates with the pipe of the helium liquefaction circuit 35. Then, when the primary side 71 and the secondary side 72 are separated, the seal member 73 is seated on the seat surface 74 of the primary side 71 and the seal member 75 is seated on the seat surface 76 of the secondary side 72. As a result, both the gas inlet 61 (gas outlet 62) and the piping of the helium liquefaction circuit 35 are closed at their open ends so that they do not communicate with the atmosphere. It should be noted that an external helium supply device (not shown) is provided in the helium liquefaction circuit 35 and controls the helium liquefaction circuit 35 to keep the helium amount constant.

The operation of the refrigeration system for a superconducting magnetic levitation vehicle having the above configuration will be described.

The superconducting magnetic levitation vehicle 10 is provided with a magnetic attraction / acting force acting between the superconducting magnet 32 and the ground coil 16.
It rises and runs using repulsion. Then, in order to generate a superconducting action in the superconducting magnet 32, liquid helium generated in the helium liquefaction circuit 35 (temperature about 4.2K)
Is used to cool the superconducting magnet 32 to a cryogenic temperature region.

That is, the gaseous helium discharged from the compressor 44 is subjected to the removal of impurities in the first gas purifier 38,
After flowing through the high-pressure side of the countercurrent heat exchanger 39, it is cooled by the low-temperature gas helium flowing through the low-pressure side, and then reaches the first freezing section 40. In the first refrigeration section 40, the cryogenic refrigerator 5
The 0 first cold head 51 cools gaseous helium to a low temperature region. Thereafter, the gas helium is supplied to the second gas purifier 41, the high pressure side of the second countercurrent heat exchanger 42,
The high-purity side of the refrigeration unit 43 and the third countercurrent heat exchanger 45 and the high-pressure side of the third refrigeration unit 46, the third gas purification device 47 and the fourth countercurrent heat exchanger 48 are purified to high purity. On
It is further cooled stepwise to a low temperature region.

The gas helium is partially liquefied by expansion at the JT valve 49, and gas-liquid mixed (mist) helium is discharged from the discharge port 36 to the liquid helium container 34. Here, only the liquid helium falls below the liquid helium container 34 to cool the superconducting magnet 32, and the gaseous helium returns from the return port 37 to the suction side of the compressor 44.

Since the gas helium returning from the return port 37 to the compressor 44 is sufficiently low in temperature, the fourth countercurrent heat exchanger 48
When flowing on the low pressure side of the third countercurrent heat exchanger 45, the low pressure side of the second countercurrent heat exchanger 42, and the low pressure side of the first countercurrent heat exchanger 39, 48, 45, 42, 3
The gas helium flowing on the high pressure side of 9 is cooled.

The gas purification in the helium liquefaction circuit 35 will be described. In the first gas purifier 38 disposed at the room temperature, oxygen, carbon monoxide, carbon dioxide, water, hydrogen and the like are to be removed, and are disposed at the low temperature. In the second gas purification device 41 and the third gas purification device 47,
Methane, carbon dioxide, water, etc. can be removed.

Here, the second gas refining device 41 and the third gas refining device 41
Since the gas purifier 47 is installed near the cryogenic refrigerator 50, the volume of each gas purifier 47 is reduced so that the amount of adsorbent to be charged is limited and the respective adsorption capacities are also limited. Therefore, in the first gas purifier 38, the volume is increased to remove impurities other than methane as much as possible.

When the superconducting magnetic levitation vehicle 10 travels, very large vibration and acceleration occur in the superconducting magnet 32, but the amount of vibration transmitted to the base 30 is suppressed by the action of the vibration damping mechanism 31 and the flexible tube 56. Can be In addition, in the first, second, and third gas purifiers 38, 41, and 47, the movable holding plate 65 is urged toward the fixed holding plate 66 by the spring 67, so that the light is transmitted from the base 30. Even if the gas purification devices 38, 41, 47 receive the vibration of the superconducting magnet 32, the internal movement of the adsorbents 63, 64 is extremely small. Therefore, the generation of powder due to the internal movement of the adsorbents 63 and 64 is extremely small. Also, in the unlikely event that each adsorbent 63,
Even if the powder 64 is powdered, it is trapped by the glass wool layers 65a and 66a and the metal filters 65b and 66b, and therefore does not flow to the downstream side of the helium liquefaction circuit 35.

[0025]

As described above, in the refrigeration system for a superconducting magnetic levitation vehicle according to the present invention, since the vibration damping mechanism is interposed between the base and the superconducting magnet, large vibration of the superconducting magnet can be obtained.
The acceleration is attenuated and transmitted to the base. The base is provided with a gas purification device for the helium liquefaction circuit. The filler is sandwiched between the fixed holding plate and the movable holding plate, and the movable holding plate is biased. Due to the means being urged toward the fixed holding plate, the amount of internal movement of the filler becomes extremely small. Therefore, powdering due to the internal movement of the filler is minimized, and contamination and clogging of the helium liquefaction circuit can be prevented, so that its performance is improved and the helium liquefaction circuit is stably operated. As a result, the superconducting magnet is surely cooled, and a stable and safe operation of the superconducting magnetic levitation vehicle becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration system for a superconducting magnetically levitated vehicle according to an embodiment of the present invention.

FIG. 2 is an enlarged configuration diagram of a main part in FIG.

FIG. 3 is an enlarged sectional view of a main part in FIG. 2;

FIG. 4 is an enlarged sectional view of a main part in FIG.

FIG. 5 shows a sectional view of a prior art gas purifier.

[Explanation of symbols]

 Reference Signs List 10 superconducting magnetic levitation vehicle, 30 base, 31 vibration damping mechanism, 32 superconducting magnet, 35 helium liquefaction circuit, 38 first gas purification device (gas purification device), 39 first countercurrent heat exchanger (countercurrent heat exchanger) ), 40 first refrigeration unit (refrigeration unit), 41 second gas purification unit (gas purification unit), 42 second countercurrent heat exchanger (counterflow heat exchanger), 43 second refrigeration unit (refrigeration unit), 44 Compressor, 45 3rd Countercurrent Heat Exchanger (Counterflow Heat Exchanger), 46 3rd Refrigeration Unit (Refrigeration Unit), 47 3rd Gas Purifier (Gas Purifier), 48 4th Countercurrent Heat Exchanger (Counterflow heat exchanger), 49 JT valve, 50 cryogenic refrigerator, 51, 52, 53 cold head, 63 chemical adsorbent (filler), 64 physical adsorbent (filler), 65 movable holding plate, 66 Fixed holding plate, 67 spring (biasing means),

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Motoaki Terai 1-1-1 Meiji Station, Nakamura-ku, Nagoya-shi, Aichi Examiner at Tokai Railway Company Shinji Uematsu (58) Field surveyed (Int.Cl . ^7, DB name) H01F 6/04 ZAA

Claims (1)

(57) [Claims] 1. A cryogenic refrigerator having a base connected to a superconducting magnetic levitation vehicle, a superconducting magnet connected to the base via a vibration damping mechanism, and a cold head disposed on the base. And a helium liquefaction circuit comprising a compressor, a gas purification device, a refrigeration unit thermally coupled to the cold head, a JT valve, and a counter-current heat exchanger for generating liquid helium for cooling the superconducting magnet. The gas purification device includes a filler filled between a fixed holding plate and a movable holding plate, and biasing means for biasing the movable holding plate toward the fixed holding plate and pressing the filler. A refrigeration system for a superconducting magnetic levitation vehicle, which is disposed on the base.