JP3332574B2 - Low-temperature fluid deep-sea charging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature fluid deep-sea charging device for charging a low-temperature fluid into the deep sea, and more particularly to a low-temperature fluid suitable for charging a liquefied carbon dioxide gas into the deep sea as a carbon dioxide gas storage site. It relates to a deep-sea input device.

[0002]

2. Description of the Related Art There has been proposed a method of liquefying carbon dioxide contained in exhaust gas from a thermal power plant or an industrial furnace and storing the liquefied carbon dioxide in, for example, an ocean at a depth of more than 700 m below the sea level. JP-A-2-80316). By the way, this liquefied carbon gas (hereinafter sometimes referred to as “liquid CO ₂ ”)
Storage in the deep sea where the density of liquid CO ₂ is greater than that of CO ₂ saturated seawater (eg, 3000 m or less).
The CO ₂ dissolved from O ₂ can be formed stratified consisting CO ₂ saturated seawater layer on top of the liquid CO _2, liquid C
It was found in the deep sea storage of O ₂ is preferred.

[0005] As an apparatus for introducing liquid CO ₂ in the deep sea of 3000~4000m deeper, it is possible to tentatively assumed deepwater dosing device shown in FIG. That is, in FIG. 4, reference numeral 1 indicates an offshore base, and approximately 30
The charging pipe 2 is provided up to the deep sea of 00 to 4000 m, and the liquid CO ₂ (low-temperature fluid 3) can be circulated through the charging pipe 2 and charged into the deep sea. In FIG. 4, reference symbol A indicates a sea surface position, reference symbol B indicates an input position, and reference symbol 2a indicates an opening at the lower end of the input pipe 2.

[0004]

The temperature distribution of seawater varies depending on the sea area, but usually, as shown in FIG. It is said that the seawater temperature decreases with increasing depth above the boundary layer water depth, and that the seawater temperature is constant (about 2 ° C.) below the temperature boundary layer water depth.

By the way, the input pipe 2 is arranged from the offshore base 1 to the deep sea (3000 to 4000 m), and when the low temperature fluid 3 such as liquefied carbon dioxide is circulated through the input pipe 2 and charged into the deep sea, The temperature of the low-temperature fluid 3 is gradually increased by receiving heat from seawater at a temperature higher than the solidification temperature T (−2 ° C.) of
(The lower end opening 2a of the charging pipe 2). And during this time,
The temperature of the low-temperature fluid 3 changes as shown by a curve a in FIG.

In this case, there is no problem if the temperature of the low-temperature fluid 3 is higher than the freezing temperature T of the seawater at the charging position B. However, if the temperature of the low-temperature fluid 3 at the charging position B is lower than the freezing temperature T of the seawater. The seawater around the lower end opening 2a of the input pipe 2 is solidified, and the lower end opening 2 of the input pipe 2 is solidified.
There is a problem that blockage a may occur, or that the solidified seawater rises by buoyancy and diffuses the supplied low-temperature fluid 3 into the seawater.

Normally, the seawater temperature in the deep sea is about 2 ° C. as described above, and the flow velocity of the seawater in the deep sea is as slow as about 0.02 m / sec as shown in FIG. 6 (that is, heat transfer is poor).
Therefore, in the deep sea, the rate of temperature rise of the low-temperature fluid is small, and the seawater temperature is close to the seawater solidification temperature T, so that the above-described problem is likely to occur. It is an object of the present invention to provide a low-temperature fluid deep-sea charging device that solves such a problem.

[0008]

According to a first aspect of the present invention, there is provided a low-temperature fluid deep-sea charging apparatus, wherein an upper end is attached to an offshore base and a lower end is mounted. It is equipped with a low-temperature fluid inlet pipe that opens at the deep-sea inlet position, and a cylinder is attached with a space around the outer periphery of the inlet pipe to pump seawater near the sea surface.
A seawater circulation means for heating provided with a pump and piping for raising and pressurizing and forcibly flowing the space from above is provided.

According to a second aspect of the present invention, there is provided the low-temperature fluid deep-sea charging apparatus according to the first aspect, wherein the outlet temperature of the low-temperature fluid at the charging position of the charging pipe is equal to the surrounding seawater. The position of the lower end opening of the cylindrical body is set so as to be equal to or higher than the freezing temperature.

Furthermore, the cryogenic fluid deepwater dosing device according to claim 3, in cryogen deepwater dosing device according to claim 1 or 2, heated by the seawater flowing through the space during flow down the injection tube The position of the upper end opening of the cylindrical body is set such that the temperature of the low-temperature fluid is not higher than the saturation temperature at the pressure in the depth direction position in the charging pipe. I have.

[0011]

In the low-temperature fluid deep-sea charging apparatus of the present invention, the low-temperature fluid flowing down the injection pipe is heated by the seawater flowing through the space formed between the outer peripheral portion of the injection pipe and the cylindrical body. This is performed, and the temperature of the inlet pipe of the low-temperature fluid can be increased. Also, by appropriately selecting the positions (depths) of the upper end opening and the lower end opening of the cylindrical body, it is possible to prevent the low temperature fluid from being gasified in the middle of the charging pipe, and to control the outlet temperature of the low temperature fluid around. The action of heating above the freezing temperature of seawater is performed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A low-temperature fluid deep-sea charging apparatus as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side sectional view, FIG. 2 is a graph showing the results of the experiment, and FIG. FIG. 4 is a perspective view of a double tube portion used for the first embodiment. The same reference numerals in FIGS. 1 to 3 as those in FIGS. 4 to 7 indicate almost the same contents.

Also in the case of this embodiment, in order to introduce the low-temperature fluid (liquid CO ₂ ) 3 into the offshore base 1 into the deep sea (depth of 3000 to 4000 m), a cylindrical inlet pipe whose lower end opening is opened into the deep sea. 2 are provided. Further, a cylindrical tubular body 4 is attached to a part of the outer peripheral portion of the input pipe 2 concentrically with the input pipe 2 with an annular space 7 provided between the cylindrical body 4 and the outer peripheral portion of the input pipe 2. Part 2 is formed in a double tube structure.

A pump 5 for pumping seawater near the sea surface, pressurizing the seawater and supplying it to the space 7 from above.
Is provided at the offshore base 1, and a pipe 6 connecting the discharge port of the pump 5 to the upper end opening of the space 7 is provided. The low-temperature fluid 3 flowing down the input pipe 2 is relatively near the sea surface position A. It is configured to be heated by hot seawater. Here, the positions of the upper end opening and the lower end opening of the cylindrical body 4 are determined as follows.

That is, the charging position B (for example, a water depth of 3000
The position (water depth) of the lower end opening of the cylinder 4 is determined so that the outlet temperature of the low-temperature fluid 3 in m) can be higher than the seawater freezing temperature (for example, 0 ° C.). In the case of liquid CO ₂ , since the density at 0 ° C. is larger than the density of seawater,
There is no problem because the liquid CO ₂ flowing out from the lower end opening 2a of the charging pipe 2 settles in the seawater, but when determining the position of the lower opening of the cylindrical body 4, in addition to the outlet temperature of the charging pipe 2,
In some cases, it is necessary to consider the condition that the density of the low-temperature fluid is higher than the seawater density at that time.

When the low-temperature fluid 3 is heated by seawater flowing through the space 7 in the cylindrical body 4, the temperature of the low-temperature fluid 3 is increased by the pressure at the position in the depth direction in the inlet pipe 2 (this pressure increases as the depth increases). It is necessary to prevent the temperature from becoming higher than the saturation temperature (in order to prevent gasification in the middle), and in consideration of this point, the position of the upper end opening of the cylindrical body 4 is determined.

Incidentally, when the upper end opening of the cylinder 4 is located near the sea surface, or when the entire length of the cylinder 4 is set to be longer than an appropriate length, carbon dioxide gas may be introduced into the injection pipe 2 depending on conditions. And the introduction of the low-temperature fluid 3 may become difficult, and when the entire length of the cylindrical body 4 is set shorter than an appropriate length, the outlet temperature of the low-temperature fluid 3 introduction pipe 2 becomes low. As a result, the above problem cannot be solved.

Next, an experimental example (specific demonstration example) will be described. As the input pipe 2, the lower end opening 2a has a water depth of about 3000.
In order to form a section (section length: 150m) from 100m to 250m below the sea surface of the input pipe 2 using a thick-walled cylindrical pipe with an outer diameter of 300mm and an inner diameter of 280mm A cylindrical body 4 composed of a thick cylindrical body having an outer diameter of 560 mm and an inner diameter of 540 mm was concentrically attached to the outside of the charging pipe 2. FIG. 3 shows the structure of the double pipe portion.

Then, the liquid C is passed through the opening at the upper end of the charging pipe 2.
O ₂ was introduced under the conditions of -55 ° C / 0.5 MPa / 186.4 kg / sec.
It was put in under. Further, seawater at 15 ° C. was circulated from above in the annular space of the double pipe at a flow rate of 0.88 m / sec. When the temperature of the liquefied carbon dioxide gas flowing down the charging pipe 2 was measured under the above conditions, the result indicated by the dotted line X in FIG. 2 was obtained.

That is, the outlet temperature of the liquid CO ₂ inlet pipe 2 could be raised to about 0 ° C. The temperature of the seawater flowing out of the annular space was 10 ° C. The solid line Y in FIG. 2 shows the measurement result of the temperature of the liquid CO ₂ flowing down the charging pipe 2 when the cylindrical body 4 is not attached. In this case, the outlet temperature of the liquid CO ₂ charging pipe 2 is about −22. ° C. Thus, in the experimental example, the outlet temperature of the inlet of the liquefied carbon dioxide gas was set to about 0 ° C. higher than the freezing temperature of the surrounding seawater.
And freezing in the vicinity of the lower end opening (outlet) 2a of the charging pipe 2 can be prevented.

[0021]

As described above in detail, according to the low-temperature fluid deep-sea charging apparatus of the present invention, when the low-temperature fluid is injected into the deep sea by the input pipe having a lower end opening in the deep sea, the outlet temperature of the low-temperature fluid is controlled by: It can be heated to a solidification temperature or more peripheral seawater, thereby can prevent from degradation of the seawater at the loading position of the deep sea occlude the distal end of the solidified injection tube Ruhoka, further feeding pipe The advantage is that the disadvantage that the low-temperature fluid is gasified in the middle of the process and it becomes difficult to supply the low-temperature fluid can be solved.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view of a low-temperature fluid deep-sea charging apparatus as one embodiment of the present invention.

FIG. 2 is a graph showing the results of the same experiment.

FIG. 3 is a perspective view of a double pipe structure of a charging pipe used in the experiment.

FIG. 4 is a schematic side sectional view of an imaginary low-temperature fluid deep-sea charging device.

FIG. 5 is a graph showing a relationship between seawater temperature and a position (depth) from the sea surface.

FIG. 6 is a graph showing a relationship between a seawater velocity and a position (depth) from the sea surface.

FIG. 7 is a graph showing a change in temperature of the low-temperature fluid when the low-temperature fluid is introduced into the deep sea using the apparatus of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Offshore base 2 Input pipe 2a Lower end opening 3 Low-temperature fluid 4 Cylindrical body 5 Pump 6 Piping 7 Annular space A Sea level position B Input position

Continuation of the front page (56) References JP-A-5-4043 (JP, A) JP-A-4-290541 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 19 / 00-19/32

Claims (3)

(57) [Claims] 1. A low-temperature fluid deep-sea charging device, comprising: a low-temperature fluid charging pipe whose upper end is attached to an offshore base and whose lower end is opened to a deep-sea charging position, and a space is provided around the outer periphery of the charging pipe. A cylinder is attached and the seawater near the sea surface is pumped up and pressurized.
Equipped with pump and piping for forced circulation from above
A low-temperature fluid deep-sea charging device, further comprising heating seawater circulation means. 2. The low-temperature fluid deep-sea charging device according to claim 1, wherein the outlet temperature of the low-temperature fluid at the charging position of the charging tube is equal to or higher than the freezing temperature of the surrounding seawater. The position of the lower end opening is set,
Low-temperature fluid deep-sea charging device. 3. The low-temperature fluid deep-sea charging apparatus according to claim 1 or 2, wherein the temperature of the low-temperature fluid heated by the seawater flowing through the space while flowing down the input pipe is set in the input pipe. A low-temperature fluid deep-sea charging apparatus, wherein the position of the upper end opening of the cylindrical body is set so as not to exceed the saturation temperature at the pressure in the depth direction.