JP2514529Y2 - Liquefied gas supply device for low temperature liquefied gas container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of a liquefied gas supply device for a low temperature liquefied gas container used for long-term storage of cells and microorganisms, superconductivity and the like.

(Prior Art) A conventional liquefied gas supply device for low-temperature liquefied gas is usually the third
As shown in the figure, a liquefied gas storage facility 1 including a low-temperature liquefied gas storage tank and a liquefied gas pressure container, a liquefied gas supply pipe 2, a source valve 4 including a solenoid valve, a low-temperature liquefied gas container 6, a liquid surface for low-temperature liquefied gas It is composed of a sensor 7, a liquid level controller 8, a flexible hose 9 for connection, a manual main valve 10 and the like, and generally, a plurality of low temperature liquefied gas containers 6 are installed.

Thus, the liquefied gas 11 such as liquid nitrogen stored in the low temperature liquefied gas container 6 evaporates little by heat entering from the outside of the container, and as a result, the liquid level in the container 6 gradually decreases. .

Lower limit liquid level of liquid level of liquefied gas 11 set in advance
When it drops to Lo, the liquid level sensor 7 detects this, and a valve opening signal is transmitted to the source valve 4 via the liquid level controller 8, and the source valve 4 is opened to liquefy the liquefied gas 11 at low temperature. It is supplied into the gas container 6.

Further, when the liquid level reaches the preset upper limit liquid level Lh by the supply of the low temperature liquefied gas 11, the liquid level sensor 7 detects it and sends a valve closing signal to the source valve 4 to close it. Then, the supply of the liquefied gas 11 is stopped.

When the cryogenic liquefied gas container 6 is a cryogenic storage container, the lowering rate of the liquid surface of the cryogenic liquefied gas varies greatly depending on the number of times the object to be preserved (for example, cells etc.) is taken in and out of the container 6, and usually 3 to 7 The liquid level of the liquefied gas decreases from the upper limit liquid level Lh to the lower limit liquid level Lo in a day.

By the way, in the low temperature liquefied gas container of FIG. 3, the source valve 4 is opened to store the low temperature liquefied gas 11 in the storage container 6.
When supplied to the inside, the vaporized gas existing in the supply pipe 2 and the vaporized gas generated by heat exchange with the supply pipe 2 pass through the supply pipe in the container 6 and the liquefied gas stored in the bottom of the low temperature liquefied gas container 6 11 After being discharged inside, passing through the liquefied gas 11 and rising to the space above the liquid surface, it is sequentially discharged outside the container 6.

As a result, every time the liquefied gas 11 is supplied into the low-temperature liquefied gas container 6, the vaporized gas formed by heat exchange with the supply pipe 2 passes through the heat exchange when passing through the low-temperature liquefied gas in the container. The low-temperature liquefied gas container 6 causes gasification of the low-temperature liquefied gas, resulting in increased wasteful consumption of the low-temperature liquefied gas.
When installed in a room, there is a problem that environmental pollution is caused by the release of vaporized gas.

Particularly, when the number of installed low temperature liquefied gas containers 6 is large, the supply of the liquefied gas 11 to each storage container 6 is unevenly carried out in a timely manner, so that the supply pipe is frequently pre-cooled by the liquefied gas. As a result, the amount of liquefied gas consumed is significantly increased.

On the other hand, in order to avoid the problems of vaporization loss of the liquefied gas in the container and indoor pollution due to the vaporized gas as described above, as shown by the dotted line in FIG. 3, the manual precooling valve 3 and the gas discharge pipe 5 are provided at the end of the supply pipe 2. When the liquid level sensor 7 detects the lower limit liquid level Lo, an alarm is issued, the pre-cooling valve 3 is manually opened by opening the source valve 4, and the vaporized gas until completion of pre-cooling is released to the outside. A method is also possible.

However, even in the system with the pre-cooling device, the supply pipe 2 must be pre-cooled by a manual operation every time the liquefied gas 11 is supplied to the low temperature liquefied gas container 6, which requires a lot of manpower. .

(Problems to be Solved by the Invention) The present invention has the above-mentioned problems in the conventional liquefied gas supply device for a low-temperature liquefied gas container, that is, (a) liquefied gas to various low-temperature liquefied gas containers 6 Of the liquefied gas 11 due to heat exchange with the supply pipe 2 is increased, and (b) when the liquefied gas is released indoors, the indoor environment is polluted. (C) It is intended to solve problems such as inability to automate the operation control of the liquefied gas supply device for the low-temperature liquefied gas container including the pre-cooling valve.
By making the supply timing of 11 uniform, the number of pre-cooling of the supply pipe 2 can be significantly reduced, and the amount of low temperature liquefied gas consumed by the cooling of the pipe 2 and the gasification of the low temperature liquefied gas in the container can be significantly reduced. Provide a liquefied gas supply device for a low-temperature liquefied gas container that enables automatic operation control and a significant reduction in running cost by automatically precooling the supply pipe 2 and discharging the vaporized gas to the outside. It is a thing.

(Means for Solving the Problem) In the present invention, in order to minimize the number of times of supplying the liquefied gas 11 to the low temperature liquefied gas container 6, one of the low temperature liquefied gas containers 6
When the level of the liquefied gas inside becomes the lower limit liquid level Lo, the liquefied gas 11 is forcibly supplied to other low temperature liquefied gas containers 6 whose liquid level is less than the upper limit liquid level Lh until the liquid level reaches the upper limit liquid level Lh. At the same time, the supply pipe 2 is automatically pre-cooled to release the vaporized gas to the outside.

That is, the present invention has an automatic opening / closing precooling valve 3 provided at the end of the supply pipe 2 communicating with the low temperature liquefied gas storage facility 1.
An automatic opening / closing type source valve 4 provided in a plurality of branch pipes 2a communicating with the supply pipe 2; a temperature detection sensor 15 of the supply pipe 2 provided near the outlet side of the precooling valve 3; the automatic opening / closing type use A plurality of low temperature liquefied gas containers 6 communicating with each outlet side of the main valve 4; a liquid level sensor 7 provided in each of the low temperature liquefied gas containers 6 for detecting the liquid level of an internal low temperature liquefied gas container 11; Any one of the liquid level sensors 7 has the lower limit liquid level Lo.
When the temperature sensor 15 detects the temperature, the valve opening signal 14a is transmitted to the pre-cooling valve 3, and when the input temperature signal 16 from the temperature sensor 15 is below the set temperature, the valve closing signal 14b is transmitted to the pre-cooling valve 3 and the low temperature liquefaction is performed. A valve open signal 17 to the source valve 4 of the low temperature liquefied gas container 6 whose liquid level of the gas 11 is less than the upper limit liquid level Lh
When the liquid level of the low temperature liquefied gas container 6 reaches the upper limit liquid level Lh, a valve closing signal 17b is transmitted to the source valve 4 of the low temperature liquefied gas container 6 and the liquid level is lower than the upper limit liquid level Lh. A control device 12 for transmitting a valve opening signal 17a to the source valve 4 of any one of the low temperature liquefied gas containers 6 is a basic configuration of the invention.

(Operation) When the liquid level of the low temperature liquefied gas 11 in any one of the low temperature liquefied gas containers 6 becomes equal to or lower than the preset lower limit liquid level Lo, it is detected by the liquid level sensor 7 and the liquefied gas is supplied to the control device 12. The supply request signal 13 is input. As a result, the control device 12 outputs the valve opening signal 14a to the pre-cooling valve 3 to open the pre-cooling valve 3.

As a result, the low-temperature liquefied gas flows through the supply pipe 2, exchanges heat with the pipe 2 to cool it, vaporize it sequentially, and is discharged to the outside through the precooling gas discharge pipe 5. Also, the supply pipe 2 is cooled, and the input temperature signal from the temperature sensor 15
When the temperature of 16 becomes equal to or lower than the set temperature, the control device 12 sends a valve closing signal 14b to the pre-cooling valve 3, and the position is closest to the pre-cooling valve 3 and the liquid level is lower than the upper limit liquid level Lh. The valve opening signal 17a is transmitted to the source valve 4 of the low temperature liquefied gas container 6 and the supply of the low temperature liquefied gas is started.

When the liquid level in the low temperature liquefied gas container 6 rises and reaches the preset upper limit liquid level Lh, this is detected by the liquid level sensor 7, and a valve closing signal is sent to the source valve 4 via the control device 12. 17b is transmitted, and the valve opening signal 17a is transmitted to the source valve 4 of another low temperature liquefied gas container 6 which is next next to the precooling valve 3 and whose liquid level is below the upper limit liquid level Lh. .

In the same manner, the liquefied gas 11 is continuously supplied to all the low temperature liquefied gas containers 6 whose liquid level is below the upper and lower liquid levels Lh in order from the one close to the precooling valve 3, and the liquid in all the containers 6 is discharged. The surface level is maintained at the upper limit liquid level Lh.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall system diagram of a precooling device for a liquefied gas supply pipe according to the present invention, and FIG. 2 is an operation explanatory diagram of the precooling device according to the present invention.

In the figure, 1 is a low-temperature liquefied gas storage facility consisting of a low-temperature liquefied gas storage tank such as nitrogen and a liquefied gas pressure vessel, 2 is a low-temperature liquefied gas supply pipe such as vacuum insulation pipe, 3 is an ultra-low temperature solenoid valve and ultra-low temperature Automatic opening / closing pre-cooling valve consisting of pilot type control valve etc., 4 is an automatic opening / closing source valve consisting of ultra-low temperature solenoid valve etc. attached to each branch pipe 2a of the supply pipe 2, 5 is a vaporized gas discharge pipe, and 6 is Open low temperature liquefied gas container, 7 is a liquid level sensor for low temperature liquefied gas provided in the storage container 6,
8 is a liquid level controller provided in the control device, 9 is a flexible hose that connects the source valve 4 and the low temperature liquefied gas container 6, 10 is a manual source valve provided in each branch pipe 2a, 11 is low temperature liquefied gas , 12 is a control device including a liquid level controller 8, relays, a programmable controller, etc., 13 is a liquefied gas supply request signal transmitted from the control device 12 via the liquid level sensor 7 and the liquid level controller 8, 14a And 14b are opening and closing signals of the precooling valve 3, 15 is a temperature sensor provided near the outlet side of the precooling valve 3, 16 is a temperature signal input from the temperature sensor 15 to the controller 12, and 17a and 17b are used. An open signal and a close signal of the main valve 4, 18 is a tank main valve, and 19 is a discharge gas obtained by vaporizing the low temperature liquefied gas.

When the low-temperature liquefied gas 11 is not supplied to the low-temperature liquefied gas container 6, the pre-cooling valve 3 and the source valve 4 are kept closed. Further, the tank main valve 4 is normally open.

Now, the liquid level in any of the low temperature liquefied gas containers 6 is the lower limit liquid level.
When it reaches Lo and the liquid level sensor 7 detects it, the low temperature liquefied gas supply request signal 13 is sent to the control device via the liquid level controller 8.
Entered into 12.

As shown in FIG. 2, the control device 12 first determines whether or not the liquefied gas supply request signal 13 is present (step A), and when the input of the signal 13 is confirmed, a valve opening signal 14a is transmitted to the precooling valve 3 to precool. The valve is opened (step B). This allows
Liquefied gas storage facility 1 to supply pipe 2 Low temperature liquefied gas 11
Flows in, heat exchanges with the pipe 2 and vaporizes,
It is released to the outside as the release gas 19 (step C).

On the other hand, a temperature sensor 15 provided near the outlet side of the precooling valve 3
By this, the temperature of the supply pipe 2 (or the temperature of the discharge gas 19) is detected, the detected temperature signal 16 is input to the control device 12, and the detected temperature of the supply pipe 2 is set to a set temperature (for example, When the liquefied gas 11 is nitrogen gas, it is determined whether or not the set temperature is equal to or lower than a certain temperature of about -150 ° C to -190 ° C (step D).

If the detected temperature of the supply pipe 2 is equal to or lower than the set temperature, the closing signal 14b is transmitted to the automatic opening / closing precooling valve 3 to close it (step E), and subsequently, the low temperature liquefaction at the position closest to the precooling valve 3 is continued. Whether the output signal value of the liquid level sensor 7 from the gas container 6 is different from the value corresponding to the preset upper limit liquid level Lh (that is, the liquid level is the upper limit liquid level).
If the liquid level is less than the upper limit liquid level Lh, a valve opening signal 17a is sent to the automatic open / close type master valve 4 of the low temperature liquefied gas container 6 concerned. Then, the source valve 4 is opened (step G). Further, when the source valve 4 is opened and the liquid level in the container rises due to the supply of the low temperature liquefied gas 11, it is determined from the output signal of the liquid level sensor 7 whether the liquid level of the low temperature liquefied gas has reached the upper limit liquid level Lh. When it is determined (step H) and the upper limit liquid level Lh is reached, the valve closing signal 17b is transmitted to the source valve 4 and the valve is closed (step I).

Subsequently, with respect to the low-temperature liquefied gas container 6 next to the precooling valve 3, it is judged whether the liquid level is less than the upper limit liquid level Lh as in the step A, and if the upper limit liquid level is lower than the upper limit liquid level Lh.
If it is less than Lh, the control operation from step G to step I is performed.

In this way, the internal liquid level of all the low temperature liquefied gas containers 6 is determined, and when the liquid level is less than the upper limit liquid level Lh, the low temperature liquefied gas 11 is sequentially supplied and the supply pipe 2 is pre-cooled once. When performed, the liquid level of all the low temperature liquefied gas containers 6 is maintained at the level of the upper limit liquid level Lh.

In the present embodiment, the control device 12 is configured to supply the low temperature liquefied gas 11 in order from the low temperature liquefied gas container 6 closest to the precooling valve 3, but the mounting intervals of the respective branch pipes 2a are different. When the length is short or the number of the installed containers 6 is small, the supply order of the low temperature liquefied gas 11 may be slightly changed.

Further, in the present embodiment, the control device 12 is configured to sequentially supply the low temperature liquefied gas 11 to the low temperature liquefied gas containers 6 one by one, but when the number of the low temperature liquefied gas containers 6 is small, It is also possible to simultaneously supply the low temperature liquefied gas 11 to the plurality of containers 6.

Further, in this embodiment, the supply pipe 2 is pre-cooled by opening and closing the pre-cooling valve 3 only once. However, when the supply pipe 2 is long or the pipe diameter is large, the pre-cooling valve 3 is kept constant. Piping 2 opened and closed multiple times at time intervals
It is desirable to carry out cooling in multiple stages.

In addition, in this embodiment, a direct-acting type ultra-low temperature solenoid valve is used as the automatic opening / closing precooling valve 3, but when the supply pipe 2 has a large diameter exceeding 1 ″, the direct-acting type is used. Instead of the solenoid valve, a pneumatic control valve using a so-called pilot solenoid valve may be used.

(Effect of the Invention) In the present invention, when the liquid level sensor 7 detects that the liquid level of the liquefied gas 11 in any one of the low temperature liquefied gas containers 6 is equal to or lower than the lower limit liquid level Lo. , The precooling valve 3 is opened to automatically precool the supply pipe 2 to the set temperature, and the low temperature liquefied gas 11 is sequentially supplied to all other low temperature liquefied gas containers 6 whose liquid level is less than the upper limit liquid level Lh. However, the liquid surfaces of all the low-temperature liquefied gas containers 6 are kept at the upper limit liquid surface Lh.

As a result, the number of times of supplying liquefied gas can be reduced,
It is possible to significantly reduce the amount of vaporization loss of the liquefied gas 11 that occurs with the supply of the liquefied gas.

Further, in the present invention, the pre-cooling valve 3 is an automatic opening / closing ultra-low temperature valve, the pre-cooling valve 3 is opened by the liquefied gas supply request signal 13, and the temperature sensor 15 disposed near the outlet thereof.
Detects the temperature of the supply pipe 2 during precooling by
When the detected temperature becomes less than the set value, the precooling valve 3 is automatically closed and the source valve 4 is automatically opened via the control device 12. As a result, the completion of precooling can be more accurately determined, and the system for supplying the low-temperature liquefied gas 11 can be completely automated, which can reduce the number of workers and improve work efficiency.

Further, in the present invention, the low temperature liquefied gas 11 is not supplied to the plurality of low temperature liquefied gas containers 6 at the same time, and the low temperature liquefied gas 11 is supplied one by one in sequence.
Is configured to be supplied.

As a result, the instantaneous generation amount of vaporized gas is limited to only one unit, and even when a large number of low temperature liquefied gas containers 6 are installed in the room, it is possible to prevent a decrease in the oxygen concentration in the room air with a smaller ventilation capacity. it can.

In addition, in the present invention, the low-temperature liquefied gas 11 is supplied one by one in order from the low-temperature liquefied gas container 6 located near the precooling valve 3. As a result, even when the number of installed low-temperature liquefied gas containers 6 is large, the first pre-cooling of the supply pipe 2 is sufficient, and the second pre-cooling is completely unnecessary.

As described above, the present invention has excellent practical utility.

[Brief description of drawings]

FIG. 1 is an overall system diagram of a liquefied gas supply device for a low temperature liquefied gas container according to the present invention. FIG. 2 is an operation explanatory view of the present invention. FIG. 3 is an overall system diagram of a conventional liquefied gas supply device for a low temperature liquefied gas container. Lo ...... Lower liquid level Lh ...... Upper liquid level 1 ...... Liquefied gas storage facility 2 ...... Liquefied gas supply pipe 3 ...... Precooling valve 3a …… Branch pipe 4 …… Original valve 5 …… Gas discharge pipe 6 …… Low temperature liquefied gas container 7 Liquid level sensor 8 Liquid level controller 9 Flexible hose 10 Manual source valve 11 Low temperature liquefied gas 12 Controller 13 liquefied gas supply request signal 14a … Precooling valve open signal 14b …… Precooling valve closing signal 15 …… Temperature sensor 16 …… Input temperature signal 17a …… Source valve opening signal 17b …… Source valve closing signal 18 …… Tank source valve 19 …… Outgassing gas

Claims (2)

(57) [Scope of utility model registration request] 1. An automatic opening / closing precooling valve (3) provided at the end of a supply pipe (2) communicating with a liquefied gas storage facility (1);
An automatic opening / closing type main valve (4) provided in a plurality of branch pipes (2a) communicating with the supply pipe (2); a temperature of a supply pipe (2) provided near an outlet side of the precooling valve (3) A detection sensor (15); a plurality of low temperature liquefied gas containers (6) communicating with each outlet side of the automatic opening / closing type source valve (4); Liquefied gas (11)
A liquid level sensor (7) for detecting the liquid level of the liquid; a valve open signal (14a) to the pre-cooling valve (3) when any of the liquid level sensors (7) detects the lower limit liquid level (Lo). Of the liquefied gas (11) while transmitting the valve closing signal (14b) to the pre-cooling valve (3) when the input temperature signal (16) from the temperature sensor (15) is below the set temperature. Any low temperature liquefied gas container whose surface is less than the upper limit liquid level (Lh) (6)
The valve opening signal (17a) is transmitted to the source valve (4) of the above, and the liquid level of the low temperature liquefied gas container (6) is the upper limit liquid level (L
When it reaches h), the valve closing signal (17b) is sent to the original valve (4).
And a liquid level lower than the upper limit liquid level (Lh), and a valve opening signal (17a) to the source valve (4) of any other low temperature liquefied gas container (6). (12) A liquefied gas supply device for a low-temperature liquefied gas container composed of (12). 2. A control device (12) is provided with a valve opening signal (17) in order from a source valve (4) of a branch pipe (2a) close to a precooling valve (3).
Claim (1) configured to send a) and release it
Liquefied gas supply device to the low temperature liquefied gas container according to.