JPS5997398A - Low temperature liquid container - Google Patents

Abstract

PURPOSE:To reduce evaporation loss of expensive low temperature liquid at initial filling, by providing heat transmission members in inner and outer storage tanks while encapsulating gas having lower boiling point than the temperature of storage liquid in inner tank in a bellows between said tanks. CONSTITUTION:A radiation shielding board 12 to be arranged adjacent to a low temperature storage tank 13 is formed with a vacuum insulating section 14 against the inner tank 11 while a gas encapsulating section 15 is filled with gas having lower boiling point than the temperature of low temperature liquid in the inner tank 11 and relatively high heat conductivity. In order to block leakage of gas in said section 15 to vacuum insulating section 14 and to absorb thermal shrinkage between inner tank and radiation shielding board, heat transmission members 16, 16' and bellows 24 are provided. Heat transmission members 16, 16' are made of metal having high heat conductivity, and fixed with interval to contact thermally with inner tank 11 and radiation shielding board 12. Then adsorbent having high adsorption under low temperature is filled in a space 19 provided in the heat transmission member 16 contacting with the inner tank 11. Prior to filling low temperature liquid in the inner tank 11, liquid nitrogen is filled in low temperature storage tank 13 to pre-cool the inner tank 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for storing low-temperature liquids such as liquid helium and liquid hydrogen.
The present invention also relates to improvements in containers for cryogenic liquids used when transporting low-temperature liquids.

Figure 1 shows a conventional container for cryogenic liquids of this type, (1)
(2) is a first storage tank for storing a low-temperature liquid (α) such as liquid helium, and (2) is made of a metal such as copper with good thermal conductivity and surrounds the storage tank (1) with a gap. The radiation shield plate (3) is a second plate that stores an inexpensive low-temperature liquid (751) such as liquid nitrogen, which has a higher boiling point than the low-temperature liquid (α), which is placed on the outside in contact with the radiation shield plate (2). Storage tank, (4
) are the storage tank (3) and the radiation shield plate (an outer tank disposed at a distance from each other so as to surround them), and (5H6) are the first storage tank (1) and the radiation shield plate (2), respectively. A solid-wall insulation board formed between the radiation shield plate (2) and between the radiation shield plate (2) and the outer tank (4) (the port is for supplying and discharging the low temperature liquid (α) , (8) is a low temperature liquid (h
) is a port for supplying and discharging.

The radiation shield plate (2) is cooled to near its boiling point using an inexpensive low-temperature liquid (&l), and is placed in the first storage tank (1).
The vacuum insulation section (
Compared to the case of only 5), the amount of radiant heat that enters from the outer tank (4) can be reduced, and the amount of evaporation of the expensive low-temperature liquid (a) can be reduced.

However, in the conventional container for cryogenic liquid, the first storage tank (1) contains the cryogenic liquid (3) which is still at room temperature.
At the initial stage of filling, it is necessary to cool down 4(1) to the boiling point temperature of the low temperature liquid (α), and as a result, the low temperature liquid (α)
There is an evaporation loss of α).

The present invention has been proposed in order to eliminate such drawbacks, and includes a first storage tank for storing a cryogenic liquid to be stored, which is surrounded by nine radiation shields with a gap between them, and which is in contact with the radiation shield plate and has a shield on the outside thereof. A second storage tank for storing a low-temperature liquid for reducing radiant heat is disposed in a container for low-temperature liquid, and the radiation shield plate and the second storage tank are surrounded by an external phase with a gap between the first storage tank and the second storage tank. A heat transfer member is fixedly installed on the outside, the outer surface of the first storage tank wall and the inner surface of the radiation shield plate are connected via a bellows surrounding the heat transfer member, and the first storage tank is installed inside the bellows. The present invention relates to a container for low-temperature liquid, characterized in that a gas having a boiling point lower than that of the liquid to be stored is sealed therein, and an adsorbent having strong gas adsorption properties at low temperatures is sealed in the heat transfer member.

Since the present invention is configured as described above, before filling the first storage tank with the low temperature liquid to be stored, the second storage tank is filled with the low temperature liquid for reducing radiant heat, and the second storage tank is precooled. Then, the radiation shield plate that is in contact with the storage tank and surrounds the first storage tank with a gap therebetween is cooled, and the heat transfer member fixedly installed outside the first storage tank is cooled. As a result, the liquid to be stored in the first storage tank is sealed in a bellows that connects the outer surface of the first storage tank wall and the inner surface of the radiation shield plate through the bellows that surrounds the heat transfer member. The heat transfer member is cooled by the heat transfer action of the gas with a lower boiling point, and the first
storage tank is cooled.

After the first storage tank has thus been cooled to the same temperature as the second storage tank, the first storage tank is filled with the cryogenic liquid to be stored.

Since the temperature of the stored low-temperature liquid is lower than the temperature of the second storage tank, the first storage tank, the heat transfer member, and the gas adsorbent that has strong gas adsorption properties at low temperatures sealed in the heat transfer member is cooled by history. As a result, most of the sealed gas is adsorbed by the adsorbent due to its gas adsorption action at low temperatures.

As a result, the heat transfer effect of the gas decreases.

Therefore, while the stored low-temperature liquid is stored in the first storage tank, the amount of heat that enters from the second storage tank, which is higher in temperature than the first storage tank, is small, and the expensive low-temperature liquid in the first storage tank is Evaporation loss can be reduced.

Note that when the stored low-temperature liquid in the first storage tank is discharged and the temperature of the storage tank rises, the gas adsorbed by the adsorbent is released again into the gas sealing part, and the heat transfer effect of the gas becomes large. Return.

The present invention will be described below with reference to embodiments shown in FIGS. 2 and 6.

The drawings show a state in which the present invention is applied to a portion corresponding to part (2) of the conventional cryogenic liquid container shown in FIG.

αυ is an inner tank constituting the first storage tank (I2 is a radiation shield plate disposed in contact with the low temperature storage tank (1, 11) constituting the second storage tank, a4 is the shield plate a and the inner tank housing (151 is a gas filling part for sealing in a gas having a relatively high thermal conductivity and a boiling point temperature lower than the temperature of the low-temperature liquid in the inner tank I; For example, when filling the inner tank αυ with liquid helium or liquid nitrogen in the low-temperature storage tank (13), hydrogen gas, helium gas, or the like is used as the sealed gas.

(16i? (16 is made of metal such as copper with high thermal conductivity, and one end is the inner tank Uυ and the radiation shield plate α.
This is a heat transfer member attached to 2 by screws αη, welding, etc. so as to be in thermal contact with it. Also, be sure to make sure that the heat transfer member (16) and the heat transfer member (16) do not come into contact with each other in the gas enclosure (I
).

A9 is a space provided inside the heat transfer member (161) that contacts the inner tank ←υ, and (to) is a molecular sieve (161) that is filled with the same space a9 and has strong gas adsorption properties at low temperatures.
It is a porous adsorbent such as artificial zeolite) or activated carbon. The space a9 is filled with the adsorbent (a) in an amount sufficient to adsorb the gas in the gas-filled portion a9.

Qυ is a gas passage connecting gas filling part aS and space agI, (2) is gas filling part QCJK space Q1, gas passage 1
2. The gas passage for filling in the gas through the phantom (to) is the gas filling tube, and after filling the gas, the gas passes through the vacuum insulation part (14).
) The tip of the trap is sealed to prevent K from leaking.

In addition, (2) is made of stainless steel or the like with low thermal conductivity, and the heat transfer member (161 and It is a joined, sealed bellows.

Similarly, the thickness of Rose C24) is as thin as possible, and the number of peaks is increased to increase the heat transfer distance, so that the amount of heat transferred by solid heat conduction is reduced.

In addition, when cooled, the inner tank 0υ and the radiation shield plate α
The thermal contraction that occurs in 3 can also be absorbed by the bellows 3.

Since the illustrated embodiment is configured as described above, the cryogenic storage tank (13
The low-temperature storage tank α is pre-cooled by filling it with a low-temperature liquid such as liquid nitrogen. As a result, the radiation shield plate a is cooled,
The heat transfer part (16') is cooled through the radiation shield plate α, and the heat transfer member a6) is cooled by the heat transfer action of the gas in the gas filled part a3, and as a result, the inner tank Uυ is cooled.

After the inner tank Uυ is cooled to the same temperature as the low temperature storage tank 03, the low temperature liquid to be stored is filled into the inner tank side.

However, since the temperature of the stored low-temperature liquid is lower than that of the low-temperature storage tank (131), the inner tank αυ, heat transfer member aθ, and adsorbent (2) are further cooled. Due to the adsorption action, most of the gas in the rice in the gas-filled portion 0 is adsorbed by the adsorbent (a), and the heat transfer action of the gas is reduced.

Therefore, while the inner tank Ql)K is storing the stored low-temperature liquid, the amount of heat that enters from the low-temperature storage tank (131) whose temperature is higher than that of the inner tank (11) is small, and the evaporation loss of the low-temperature liquid in the inner tank aυ is also small.

Then, the stored low temperature liquid in the inner tank Uυ is discharged and the inner tank (
When the temperature of 1) rises, the gas adsorbed by the adsorbent is released again into the gas-filled portion 09, returning to a state where the heat transfer effect of the gas is large.

In this way, when filling the inner tank αυ with the low temperature liquid to be stored, since the inner tank Uυ is cooled to a temperature comparable to that of the low temperature storage tank 0.1, it is possible to reduce the evaporation loss of the expensive liquid to be stored during initial filling. You can do less.

Although the present invention has been described above with reference to embodiments, the present invention is of course not limited to these embodiments, and can be modified in various ways without departing from the spirit of the invention. be.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional cryogenic liquid container, FIG. 2 is an enlarged longitudinal sectional view showing an embodiment of the cryogenic liquid container according to the present invention, and FIG. This is a meal plan. (lυ...inner tank, scream...radiation shield version, 03
...-low temperature storage tank, 15]...gas filling part, (lb
l(16')...Heat transfer member, (4)...Adsorbent,
(7! Xun... Bellows sub-agent, patent attorney Shige Okamoto, 2 people outside of the text Figure 3)

Claims (1)

[Scope of Claims] A first storage tank for storing a low-temperature liquid to be stored is surrounded by a radiation shield plate with a gap therebetween, and a second storage tank for storing a low-temperature liquid for reducing radiant heat outside the radiation shield plate is in contact with the radiation shield plate. A low temperature liquid container is provided with a storage tank, and the radiation shield plate and the second storage tank are surrounded by an outer tank with a space therebetween, in which a heat transfer member is fixed to the outside of the first storage tank, The outer surface of the first storage tank wall and the inner surface of the radiation shield plate are connected through a bellows surrounding the heat transfer member, and a gas having a boiling point lower than that of the liquid to be stored in the first storage tank is contained in the bellows. A container for low-temperature liquid, characterized in that the heat transfer member is filled with an adsorbent having a strong adsorption property for low-temperature gases.