JP3818328B2 - Cryogenic cable cooling apparatus and cooling method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling device and a cooling method for a cryogenic cable.
[0002]
[Prior art]
A technique for cooling a cryogenic cable is shown in FIG.
This apparatus includes a refrigerant supply tank 1, a storage tank 2, a refrigerator 3, a cooling unit having pipes connecting these and the cables 4, and a cable 4 serving as a cooled part. The refrigerant in the storage tank 2 is sent to the cable 4 through the refrigerator 3, and the cable 4 is cooled, and then the circulation cooling is performed to collect it in the storage tank 2. The refrigerant is supplied from the refrigerant supply tank 1 to the storage tank 2 and is pumped to the refrigerator by the pump 6. The refrigerator is provided with a refrigerant flow meter 9.
[0003]
When starting the cooling, first, the valve 5 is operated to store the refrigerant in the storage tank 2. Next, the pump 6 is operated with the valve 8 closed. Subsequently, the valve 8 is opened to adjust the flow rate of the refrigerant, and the refrigerant is circulated within a range not exceeding the allowable value of the flow meter 9 to cool the cooling unit and the cable 4. When the cooling of the cooling unit and the cable 4 is completed, the valve 8 is fully opened, and the cooling of the storage tank 2 → the refrigerator 3 → the cable 4 → the storage tank 2 is performed.
Note that terminal portions 13A and 13B are formed at both ends of the cable 4, and refrigerant is stored inside the terminal portions 13A and 13B.
[0004]
[Problems to be solved by the invention]
However, the above technique has the following drawbacks.
(1) Normally, the flow meter of a refrigerator has a turbine and has a structure that is vulnerable to sudden refrigerant pressure fluctuations. Therefore, if the cooling unit and the cable having a large heat capacity are cooled together, the flow meter may be damaged due to a rapid pressure fluctuation due to evaporation of the refrigerant. On the other hand, in order to cool the flow meter so as not to be damaged, the initial cooling speed must be slowed down, and it takes a long time to operate the cooling device.
[0005]
{Circle around (2)} The above cooling device needs to fill the cooling part and the cable with the refrigerant, and the ratio of the volume of the refrigerant in these is much larger in the cable than in the cooling part. If a failure occurs in the cooling unit during operation, it is necessary to raise the temperature by temporarily removing not only the refrigerant in the cooling unit but also the refrigerant in the cable not related to repair. Therefore, the temperature rise time and the loss of the refrigerant are problematic.
[0006]
Therefore, the main object of the present invention is to prevent the cooling part from being damaged due to a sudden refrigerant pressure fluctuation during the initial cooling, and to facilitate the maintenance of the cooling device.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention makes cooling of the cooling part and cooling of the cable independent.
That is, the cooling device of the present invention is provided with a cooling unit having a storage tank, a refrigerator, and a circulation path that sends the refrigerant of the storage tank to the refrigerator and returns the refrigerant to the storage tank, and the refrigerant is supplied via the refrigerator. The cable connected to the cooling unit to collect the refrigerant in the storage tank, the auxiliary refrigerant tank connected to the cable and the cooling unit, the refrigerant circulation of the cooling unit and the refrigerant supply from the auxiliary refrigerant tank to the cable are independent. It is characterized by comprising a valve to be operated.
[0008]
Further, the cooling method of the present invention independently performs cooling of the cooling unit that sends the refrigerant in the storage tank to the refrigerator and collects the refrigerant in the storage tank again, and cooling of the cable that supplies the refrigerant from the auxiliary refrigerant tank to the cable. After that, the coolant is supplied to the cable from the cooling unit, and the circulating cooling is performed to collect the coolant of the cable in the storage tank.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
FIG. 1 is a schematic view showing an embodiment of the present invention.
This apparatus includes a refrigerant supply tank 1, a storage tank 2, a refrigerator 3, a cooling unit having pipes connecting these and the cables 4, and a cable 4 serving as a cooled part.
[0010]
The refrigerant supply tank 1 is connected to the storage tank 2 and supplies refrigerant (for example, liquid nitrogen) thereto. A valve 5 is provided between the tanks 1 and 2 so that the flow rate of the supplied refrigerant can be adjusted.
The storage tank 2 includes a pump 6 and pressure-feeds the refrigerant sent from the refrigerant supply tank 1 to the refrigerator. In addition, the storage tank 2 can adjust the internal pressure by a leak valve 7. Furthermore, a valve 8 is provided in the piping from the storage tank 2 to the refrigerator 3 so that the flow rate of the refrigerant to the refrigerator 3 can be adjusted.
[0011]
The refrigerator 3 cools the refrigerant sent from the storage tank 2. A flow meter 9 is provided inside the refrigerator, and the flow rate of the refrigerant sent to the cable side can be monitored. The piping drawn out from the refrigerator 3 is branched into two branches, one connected to the storage tank 2 and the other extended to the cable side. That is, a circulation path of the storage tank 2 → the refrigerator 3 → the storage tank 2 is formed by one pipe connected to the storage tank 2. A valve 10 is provided in the middle of the piping from the refrigerator 3 to the storage tank 2.
[0012]
On the other hand, the other pipe extended to the cable side is further bifurcated through the valve 11, one connected to the auxiliary refrigerant tank 12 and the other connected to the cable end portion 13A. The auxiliary refrigerant tank 12 stores the refrigerant and supplies the refrigerant to the cable 4 through the valve 14 and the terminal portion 13A.
[0013]
The terminal portions 13A and 13B are places where electric power is taken out from both ends of the cable 4. The terminal portions 13A and 13B contain a refrigerant, and the conductor 15 is immersed therein. The terminal portions 13A and 13B and the cable 4 are separated by a partition wall (for example, FRP resin), and have a structure that does not communicate with each other.
[0014]
The cable 4 has a conductor 15 disposed at the center and a pipe line 16 covering the outer periphery thereof. A refrigerant flow path is formed inside the conductor of the cable, and the refrigerant introduced into the conductor from one end portion 13A is discharged to the outer periphery of the conductor 15 on the other end portion 13B side and turned back, and the conductor 15 and the conduit are connected. 16 is led to a return pipe 17 connected to the cable 4. The return pipe 17 is connected to a circulation path from the refrigerator 3 to the storage tank 2. That is, a circulation path of the storage tank 2 → the refrigerator 3 → the valve 11 → the terminal portion 13A → the cable 4 → the return pipe 17 → the storage tank 2 is formed. Here, a valve 18 is provided in the middle of the return pipe 17, and a pressure adjusting valve 19 is also provided in the branch pipe of the return pipe 17.
[0015]
Cooling by the above apparatus is performed as follows.
First, the valve 5 is opened to supply the refrigerant from the refrigerant supply tank 1 to the storage tank 2.
[0016]
Next, the valves 8 and 10 are opened, the valves 11 and 18 are closed, and the pump and the refrigerator are started. Thereby, the circulation path of the storage tank 2 → the refrigerator 3 → the storage tank 2 is filled with the refrigerant and cooled. At this time, the refrigerant flow rate is monitored by a flow meter.
[0017]
On the other hand, the valve 14 is opened to supply the refrigerant from the auxiliary refrigerant tank to the cable. Thereby, the cable 4 and the piping up to that are cooled. At this time, gas generated by vaporization of the refrigerant is discharged to the outside from the pressure adjustment valve.
[0018]
Then, after the cooling of the cooling section and the cable is completed, the valves 10 and 14 are closed, the valves 11 and 18 are opened, the storage tank 2 → the refrigerator 3 → the valve 11 → the terminal section 13A → the cable 4 → the return piping 17 → Circulating cooling of the storage tank 2 is performed.
[0019]
In this way, cooling of the cooling section (reservoir tank 2 → refrigerator 3 → reservoir tank 2 circulation path) and cooling of the cable are performed separately to reduce the load during the initial cooling of the cooling section, and abrupt pressure Prevent damage to equipment (especially flow meters) caused by fluctuations.
[0020]
In the case of failure and maintenance, the operation of the valves 10, 11 and 18 can be performed by dividing the refrigerant flow path between the cooling unit and the cable and performing the inspection work independently of each other. In particular, the cooling unit needs to be periodically inspected, and if the cable and the refrigerant flow path can be divided at the time of the temperature rise accompanying the inspection, the temperature raising time can be shortened and the cooling time at the time of restart can be shortened.
[0021]
【The invention's effect】
As described above, according to the apparatus and method of the present invention, the cooling unit and the cable can be independently cooled, so that the thermal load on the cooling unit during the initial cooling can be reduced. Therefore, it is possible to prevent a device such as a flow meter from being damaged due to a rapid pressure fluctuation due to the vaporization of the refrigerant.
Moreover, since the cooling unit and the cable can be maintained independently, the temperature raising time during the inspection work can be shortened. Moreover, the loss of the refrigerant can also be suppressed.
[Brief description of the drawings]
FIG. 1 is a schematic view of a cooling device of the present invention.
FIG. 2 is a schematic view of a conventional cooling device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Refrigerant supply tank 2 Storage tank 3 Refrigerator 4 Cable 5 Valve 6 Pump 7 Leak valve 8 Valve 9 Flow meter
10 Valve 11 Valve 12 Auxiliary refrigerant tank 13A, 13B Terminal 14 Valve
15 Conductor 16 Pipe line 17 Return line 18 Valve 19 Pressure adjustment valve

Claims (2)

A cooling unit having a storage tank, a refrigerator, and a circulation path for sending the refrigerant of the storage tank to the refrigerator and returning it to the storage tank again;
A cable through which a refrigerant is supplied and connected to a cooling unit so as to collect the refrigerant in a storage tank;
An auxiliary refrigerant tank connected to the cable and cooling section;
A cryogenic cable cooling apparatus comprising: a valve that makes independent the refrigerant circulation in the cooling section and the refrigerant supply from the auxiliary refrigerant tank to the cable. Cooling of the cooling part that sends the refrigerant in the storage tank to the refrigerator and recovering this refrigerant to the storage tank again and cooling of the cable that supplies the refrigerant from the auxiliary refrigerant tank to the cable are performed independently, and then from the cooling part A cooling method for a cryogenic cable, characterized in that a refrigerant is supplied to the cable and circulating cooling is performed to collect the refrigerant in the cable in a storage tank.

Images