JP4065265B2 - Carbon dioxide discharge apparatus and carbon dioxide discharge method - Google Patents

Description

  The present invention relates to a carbon dioxide discharge device and a carbon dioxide discharge method.

In recent years, global warming has become a major social problem. Accordingly, it has become particularly important to suppress an increase in the concentration of carbon dioxide (CO ₂ ) having a greenhouse effect, which has been pointed out to cause global climate change, in the atmosphere.
From such a background, as one of the measures to suppress the increase in carbon dioxide concentration, after recovering the carbon dioxide in the combustion exhaust gas discharged from a thermal power plant, etc., and liquefying it into liquefied carbon dioxide, There has been proposed a concept of isolating carbon dioxide from the atmosphere over a long period of time by sending it into deep seawater at a depth of about 1000 m or more.
As an apparatus for sending liquid carbon dioxide into deep seawater, for example, as described in Patent Documents 1 and 2 below, there is an apparatus for sending liquid carbon dioxide into deep seawater through a conduit suspended from the sea.

Since this conduit has a total length of 1000 m or more, it is formed by newly adding a pipe to this pipe while sinking a pipe having a length that is easy to handle.
Specifically, the pipe is connected to the upper end of this pipe while the pipe is filled and submerged with seawater, or the lower end of the pipe constituting the lowermost end of the pipe is closed to close the seawater into the pipe. It is formed by sequentially connecting a pipe to the upper end of this pipe while preventing intrusion.

Japanese Patent Laying-Open No. 2002-85958 (paragraph [0008] and FIG. 1 etc.) Japanese Unexamined Patent Publication No. 2003-1101 (paragraph [0024] and FIG. 1 etc.)

In the method of connecting pipes while filling the pipes with seawater, seawater enters the pipes. Since liquid carbon dioxide is kept at a low temperature of about −20 ° C. to −50 ° C. in order to maintain a liquid phase, when liquid carbon dioxide is supplied into a conduit in which seawater has entered, liquid carbon dioxide and sea water Hydrate is formed at the boundary surface of the tube and the conduit is clogged.
In the method of connecting the pipes by closing the lower end of the lowermost pipe, it is possible to prevent the intrusion of seawater into the inside of the conduit, but the conduit contains moist air that has been connected. ing. For this reason, when liquid carbon dioxide is supplied into the conduit, the moisture in the humid air and the liquid carbon dioxide are mixed with each other to form a hydrate, and the conduit is clogged.
Therefore, in any of the above methods, prior to the supply of liquid carbon dioxide, the seawater or wet air in the conduit is replaced with a purge gas, and then the purge gas and liquid carbon dioxide are replaced, and then the liquid dioxide is supplied to the conduit. It is necessary to supply carbon.

However, the lower end of the conduit reaches a depth of 1000 m or more, and receives a huge seawater pressure (about 100 atm).
For this reason, in order to discharge seawater, humid air, or used purge gas in the conduit from the lower end, it is necessary to apply a back pressure that exceeds the seawater pressure applied to the lower end of the conduit. Since it is necessary to drive the power source, carbon dioxide is further generated.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a carbon dioxide discharge device and a carbon dioxide discharge method that require less power and can suppress further generation of carbon dioxide. And

In order to solve the above-mentioned problems, the carbon dioxide discharge apparatus and the carbon dioxide discharge method of the present invention employ the following means.
That is, the carbon dioxide discharge apparatus according to the present invention is a carbon dioxide discharge apparatus that discharges liquid carbon dioxide supplied from a liquid carbon dioxide supply apparatus on the sea into the sea, and is suspended from the sea to supply the liquid carbon dioxide. A conduit for supplying the liquid carbon dioxide from the upper end of the apparatus; a nozzle connected to the lower end of the conduit; and a fluid interposed between the lower end of the conduit and the nozzle to flow into the conduit from the nozzle A non-return valve for preventing the backflow of the gas, and the conduit is constituted by a plurality of conduits. As the conduit, an inner conduit is provided on the radially inner side, and an outer tube is disposed on the radially outer side. Double pipes with passages are used, and some of the pipes have lower ends connected to other pipes, and exhaust pipes are connected to the upper ends of the other pipes. A carbon discharge apparatus is provided.

In the carbon dioxide discharge device configured as described above, when the unnecessary gas (wet air or used purge gas) in the conduit is replaced with a fluid such as purge gas or liquid carbon dioxide, a part of the pipelines constituting the conduit is included. When a fluid is supplied into the pipe line from the upper end, unnecessary fluid that has been in the pipe line is pushed out from the lower end of the pipe line by the fluid, and in the pipe line. Is filled with the fluid.
Seawater pressure is applied to the check valve at the lower end of the conduit, and fluid is not discharged from the lower end of the conduit until the pressure in the conduit exceeds the seawater pressure. For this reason, the unnecessary gas pushed out from some pipes is sent into other pipes.

  Furthermore, if the supply of fluid into some pipelines is continued, the fluid is also fed into the other pipelines from the lower ends of some pipelines and fills the other pipelines from the lower end side. The unnecessary gas fed into the other pipe is pushed out toward the upper end. In particular, when the fluid supplied into some of the pipes is liquid carbon dioxide, the density of the liquid carbon dioxide is higher than that of the gas. Since it accumulates at the lower end side of the path, unnecessary gas in other pipes is surely pushed out to the upper end side.

In this way, the unnecessary gas pushed out to the upper end side of the other pipeline is discharged out of the conduit by the exhaust device connected to the upper end of the other pipeline. Here, for example, a gas venting valve or an exhaust pump is used as the exhaust device.
As described above, in this carbon dioxide discharge device, since unnecessary gas in the conduit can be taken out from the upper end, it is used for replacement of unnecessary gas in the conduit as compared with the case where the unnecessary gas in the conduit is pushed out from the lower end of the conduit. The supply pressure of the fluid can be significantly reduced. For this reason, less power is required to replace the unnecessary gas in the conduit.

In this carbon dioxide discharge device, wherein the conduit, an internal conduit is provided radially inwardly, that is composed by a double pipe outer pipe is provided radially outward.

In the carbon dioxide discharge device configured as described above, either one of the internal pipe and the external pipe of the double pipe is the partial pipe, and the other is the other pipe.
That is, since the conduit can be constituted by a single double tube, the resistance generated in the conduit during towing can be reduced.

  In this carbon dioxide discharge device, the conduit may be constituted by an outer tube and an inner tube that is inserted into the outer tube so as to be extractable.

In the carbon dioxide discharge apparatus configured as described above, the inner pipe itself constitutes one of the partial pipe and the other pipe, and the outer pipe and the inner pipe also form the one pipe. The other of the pipe and the other pipe is configured.
As a result, only the outer pipe is exposed to the sea, and the resistance generated in the pipe during towing is small, and seawater pressure is not applied to the inner pipe, so the strength level required for the pipe is low, and the manufacturing cost is low. Is low.
Furthermore, since the inner pipe can be extracted from the sea to the outside of the outer pipe, maintenance is easy when the inner pipe is clogged.

In the carbon dioxide discharge device, wherein the lower end part of the conduit, the internal pressure of the portion of the conduit said, may be a pressure maintenance device for maintaining the pressure on the vapor pressure of carbon dioxide provided.

In the carbon dioxide discharge device configured as described above, the internal pressure of some of the pipes is maintained at a pressure higher than the pressure at which carbon dioxide does not vaporize (70 to 80 kg / cm ² abs or higher near 20 ° C.). Even if liquid carbon dioxide is supplied into some pipelines , the liquid carbon dioxide is not vaporized and filled in some pipelines in the liquid phase, so the supply efficiency is good and the flow meter The supply of liquid carbon dioxide can be satisfactorily performed, for example, the supply amount of liquid carbon dioxide can be measured.
Also, under this pressure, clogging due to carbon dioxide dry ice does not occur, and liquid carbon dioxide can be supplied satisfactorily.
Here, for example, a back pressure valve is used as the pressure maintaining device.

  In this carbon dioxide discharge device, the part of the pipes includes a plug that partitions the inside of the part of the pipes in an airtight and liquid-tight manner and is movable to the lower end side, and a portion near the lower end of the part of the pipes. A plug recovery portion that is provided and has an inner diameter larger than the diameter of the plug may be provided.

Plug In thus configured carbon dioxide discharge apparatus, when performing the replacement of unnecessary gas and fluid part of the conduit, inserting the plug from the top part of the conduit, the fluid wherein the substituent By applying the back pressure to the plug, the plug moves to the lower end and pushes unnecessary gas in a part of the pipe line to the lower end.
In other words, the unnecessary gas in some pipes and the fluid to be replaced are separated, and the unnecessary gas and fluid in some pipes are replaced, so that the replacement can be performed efficiently. it can.
Further plug is moved and reaches the plug collecting portion provided in the vicinity of the lower end of a portion of the conduit, since the plug is released from the restriction by the internal surface of the portion of the conduit, more of the plug descends In addition, the fluid is supplied to the lower ends of some pipes through the gap between the plug and the inner surface of the plug recovery part.
Here, when the conduit is composed of an outer tube and an inner tube that is inserted into the outer tube so as to be extractable, and the inner tube is the partial conduit , the inner tube is By pulling out from the outer tube to the sea, the plug recovered by the plug recovery unit can be recovered and the inner tube and plug can be reused.

  In the carbon dioxide discharge device, the exhaust device may include a purge gas recovery device that recovers unnecessary gas discharged from the conduit.

  In the carbon dioxide discharge device configured as described above, when the purge gas in the conduit is replaced with liquid carbon dioxide, the purge gas taken out from the conduit can be recovered and reused.

In the carbon dioxide discharge method according to the present invention, liquid carbon dioxide is supplied from a liquid carbon dioxide supply device on the sea to a conduit suspended from the sea into the sea, and the liquid carbon dioxide is introduced into the sea from a nozzle provided at the lower end of the conduit. A carbon dioxide discharge method for discharging, wherein the conduit is constituted by a plurality of conduits, and the conduit is provided with an internal conduit radially inward and an external conduit radially outward. constituted by a tube, prior to the discharge working of the liquid carbon dioxide, wherein a portion of the conduit, by supplying fluid from the upper end, the part of the conduit and the other conduit The unnecessary gas is replaced with the fluid.

In this carbon dioxide discharge method, unnecessary gases (wet air and used purge gas) that existed in some pipes are partly caused by a fluid such as purge gas or liquid carbon dioxide supplied in some pipes. This part of the pipeline is filled with the fluid.
Seawater pressure is applied to the check valve at the lower end of the conduit, and fluid is not discharged from the lower end of the conduit until the pressure in the conduit exceeds the seawater pressure. For this reason, the unnecessary gas pushed out from some pipes is sent into other pipes.

  Furthermore, if the supply of fluid into some pipelines is continued, the fluid is also fed into the other pipelines from the lower ends of some pipelines and fills the other pipelines from the lower end side. The unnecessary gas fed into the other pipe is pushed out toward the upper end. In particular, when the fluid supplied into some of the pipes is liquid carbon dioxide, the density of the liquid carbon dioxide is higher than that of the gas. Since it accumulates at the lower end side of the path, unnecessary gas in other pipes is surely pushed out to the upper end side.

In this way, the unnecessary gas pushed out to the upper end side of the other pipeline is discharged out of the conduit by the exhaust device connected to the upper end of the other pipeline.
Thus, in this carbon dioxide discharge method, unnecessary gas in the conduit can be taken out from the upper end. Therefore, in the replacement operation of unnecessary gas in the conduit prior to the discharge of liquid carbon dioxide, unnecessary gas in the conduit is performed. Compared with the case where the pressure is pushed out from the lower end of the conduit, the supply pressure of the fluid to be replaced can be significantly reduced. For this reason, less power is required to replace the unnecessary gas in the conduit.

In the carbon dioxide discharge method according to the present invention, liquid carbon dioxide is supplied from a liquid carbon dioxide supply device on the sea to a conduit suspended from the sea into the sea, and the liquid carbon dioxide is introduced into the sea from a nozzle provided at the lower end of the conduit. A carbon dioxide releasing method for discharging, wherein the conduit is constituted by a plurality of conduits, and the conduit includes an outer tube forming the conduit, and the conduit inserted into the outer tube so as to be extractable. An inner pipe is used, and a part of the pipes is configured such that a lower end is connected to the other pipes, and the upper end is placed in the part of the pipes before the liquid carbon dioxide is discharged. By supplying the fluid from the above, unnecessary gas in the part of the pipes and the other pipes is replaced with the fluid.

  In the carbon dioxide discharge apparatus and the carbon dioxide discharge method configured as described above, since the power required for replacing the unnecessary gas in the conduit is small, the amount of carbon dioxide generated during the carbon dioxide discharge operation can be small.

Embodiments according to the present invention will be described below with reference to the drawings.
[First embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIG.
A carbon dioxide discharge apparatus 1 according to the present embodiment is provided in a ship that sails on the sea, and includes a liquid carbon dioxide supply apparatus 2 provided on the ship, and a liquid carbon dioxide supply apparatus that is suspended from the ship. 2 has a conduit 3 to which liquid carbon dioxide is supplied from the upper end, and a nozzle 4 connected to the lower end of the conduit 3 and held at a water depth of 1000 m to 2000 m.
A check valve 5 is interposed between the lower end of the conduit 3 and the nozzle 4 to prevent the backflow of fluid from the nozzle 4 into the conduit 3.

The liquid carbon dioxide supply device 2 is provided and stored on a storage tank 11 in which liquid carbon dioxide is stored, a carbon dioxide supply pipe 12 connecting the storage tank 11 and the conduit 3, and a carbon dioxide supply pipe 12. And an LCO ₂ pump 13 for pumping liquid carbon dioxide supplied from the tank 11 into the conduit 3.
In the present embodiment, as the LCO ₂ pump 13, a large-capacity LCO ₂ pump 13 a used during the discharge operation of liquid carbon dioxide, and the filling operation of liquid carbon dioxide into the conduit 3 performed prior to the discharge operation of liquid carbon dioxide The small-capacity LCO ₂ pump 13b used in the above is provided in parallel between the storage tank 11 and the conduit 3, and these LCO ₂ pumps 13 can be used properly according to work.
A flow meter 14 for measuring the amount of liquid carbon dioxide supplied from the small-capacity LCO ₂ pump 13b to the conduit 3 is provided between the small-capacity LCO ₂ pump 13b and the conduit 3 in the carbon dioxide supply line 12. Yes.

The conduit 3 is composed of a plurality of conduits, and some of the conduits are connected to other conduits at the lower ends.
In the present embodiment, the conduit 3 includes an outer tube 16 and an inner tube 17 that can be extracted into the outer tube 16 and is inserted to the vicinity of the lower end thereof. Specifically, the inner pipe W1 is constituted by the inner pipe 17, and the outer pipe W2 is constituted by the pipe constituted by the outer pipe 16 and the inner pipe 17.
Further, each of the inner pipe line W1 and the outer pipe line W2 has a configuration in which a plurality of pipes are connected in series.
Here, a small-capacity LCO ₂ pump 13b is connected to the upper end of the inner conduit W1, and a large-capacity LCO ₂ pump 13a is connected to the upper end of the outer conduit W2.

A purge gas supply device 21 for supplying a purge gas used for purging in the conduit 3 is connected to the upper end of the conduit 3.
The purge gas supply device 21 includes a storage tank 22 that stores a purge gas made of an inert gas such as nitrogen (N ₂ ) gas, a purge gas supply line 23 that connects the storage tank 22 and the conduit 3, and a purge gas supply line 23 and a compressor 24 that pumps the purge gas in the storage tank 22 into the conduit 3.

In the present embodiment, the purge gas supply line 23 is connected to a portion of the carbon dioxide supply line 12 between the small-capacity LCO ₂ pump 13b and the flow meter 14 on the downstream side of the compressor 24. The purge gas can be supplied into the inner pipe W1 through the pipe 23 and the carbon dioxide supply pipe 12.
In the purge gas supply line 23, a first valve 26 is provided between the compressor 24 and the carbon dioxide supply line 12. By operating the first valve 26, the purge gas supply line 23 can be opened and closed. To be done.

Further, the purge gas supply pipe 23 is connected to the upper end of the outer pipe W2 on the downstream side of the compressor 24, and the purge gas can be supplied into the outer pipe W2 from the upper end.
In the purge gas supply pipe 23, a second valve 27 is provided between the compressor 24 and the outer pipe W2. By operating the second valve 27, the purge gas supply pipe 23 is opened and closed. It is like that.

Moreover, the pressure maintenance apparatus 31 which maintains the internal pressure of the inner side pipeline W1 is provided in the lower end of the inner side pipeline W1. The pressure maintaining device 31 maintains the internal pressure of the inner pipe line W1 above the set value by restricting the discharge of the fluid from the lower end of the inner pipe line W1 until the internal pressure of the inner pipe line W1 exceeds the set value. For example, it is constituted by a back pressure valve.
In this embodiment, the set value of the pressure maintaining device 31 is set to be equal to or higher than the vapor pressure of carbon dioxide (70 to 80 kg / cm ² abs or higher near 20 ° C.).

In addition, an exhaust device 36 is connected to the upper end of the outer duct W2.
In the present embodiment, the exhaust device 36 includes an exhaust passage 37 connected to the upper end of the outer pipe W2 and an exhaust pump 38 that sucks the gas in the conduit 3 through the exhaust passage 37. Further, in the exhaust passage 37, a vent valve 39 that opens the exhaust passage 37 to a marine atmosphere is provided between the outer pipe W2 and the exhaust pump 38.
Here, in the present embodiment, a vacuum pump is used as the exhaust pump 38 so that the gas in the conduit 3 is reliably exhausted.

  In the carbon dioxide discharge device 1 configured as described above, the assembly of the conduit 3 is performed at sea.

  Hereinafter, the carbon dioxide emission when the pipe constituting the inner pipe W1 and the pipe constituting the outer pipe W2 of the conduit 3 are sequentially connected with the lower end of the lowermost pipe closed. The operation of the device 1 will be described.

Since the inside of the conduit 3 assembled in this manner is filled with wet air at sea, a purge operation in the conduit 3 is performed prior to the supply of liquid carbon dioxide into the conduit 3.
Hereinafter, the purge operation in the conduit 3 in this case will be described.
First, the operation of discharging wet air in the conduit 3 is performed. Specifically, the first valve 26 and the second valve 27 of the purge gas supply device 21 and the vent valve 39 of the exhaust device 36 are closed to make the exhaust of the exhaust device 36 in a state where the space in the conduit 3 is a sealed space. The pump 38 is activated to exhaust the humid air in the conduit 3.

Next, a purge gas filling operation into the conduit 3 is performed. Specifically, with the exhaust pump 38 stopped, the first valve 26 and the second valve 27 are opened to fill the conduit 3 with the purge gas. The filling pressure of the purge gas at this time is set to a pressure exceeding the pressure range (4.25 kg / cm ^{2 in} gauge pressure) where carbon dioxide is converted to dry ice. In the present embodiment, the purge gas filling pressure is 10 kg / cm ² .

Finally, a replacement operation of the purge gas in the conduit 3 and liquid carbon dioxide is performed. Specifically, with the first valve 26 and the second valve 27 of the purge gas supply device 21 closed, the small-capacity LCO ₂ pump 13b of the liquid carbon dioxide supply device 2 is operated, and the pressure of the purge gas in the conduit 3 Liquid carbon dioxide is supplied to the inner pipe W1 of the conduit 3 from the upper end side.

  By supplying liquid carbon dioxide from the upper end into the inner pipe W1 in this way, the purge gas that has been in the inner pipe W1 is pushed out from the lower end of the inner pipe W1 by the liquid carbon dioxide, The inside of the pipe line W1 is filled with liquid carbon dioxide.

  Here, as described above, the internal pressure of the inner pipe W1 is maintained by the pressure maintaining device 31 to be equal to or higher than the vapor pressure of carbon dioxide. Thereby, even if liquid carbon dioxide is supplied into the inner pipe line W1, the liquid carbon dioxide is kept in a liquid phase and does not become dry ice, and the inner pipe line W1 is not easily clogged. Further, since the liquid carbon dioxide is not vaporized in this way and is filled in the inner pipe line W1 in a liquid phase, the liquid carbon dioxide supply efficiency by the liquid carbon dioxide supply device 2 is good, and the liquid by the flow meter 14 The supply of liquid carbon dioxide can be satisfactorily performed, such as the measurement of the supply amount of carbon dioxide.

Seawater pressure is applied to the check valve 5 at the lower end of the conduit 3, and the purge gas is not discharged from the lower end of the conduit 3 until the pressure in the conduit 3 exceeds the seawater pressure. For this reason, the purge gas pushed out from the inner pipe W1 is sent into the outer pipe W2.
When the supply of liquid carbon dioxide into the inner pipeline W1 is continued, liquid carbon dioxide is also fed into the outer pipeline W2 from the lower end of the inner pipeline W1, and fills the outer pipeline W2 from the lower end side. Therefore, by opening the vent valve 39 of the exhaust device 36, the purge gas sent into the outer conduit W2 is pushed out toward the upper end and is released to the atmosphere through the vent valve 39.

Here, since the inside of the outer conduit W2 is pressurized by the purge gas to a pressure exceeding the pressure range in which carbon dioxide is dry iced, clogging due to carbon dioxide dry ice does not occur in the outer conduit W2, Liquid carbon dioxide can be supplied satisfactorily.
Further, since the seawater temperature in the region where the lower end of the conduit 3 is located is sufficiently low, about 5 ° C., the liquid carbon dioxide supplied from the lower end of the inner conduit W1 to the outer conduit W2 is in a liquid phase. It is kept. Since the liquid carbon dioxide has a higher density than the purge gas, the liquid carbon dioxide wraps around the lower side of the purge gas in the outer pipe W2, and accumulates on the lower end side of the outer pipe W2. The purge gas in the pipe line W2 is effectively pushed out to the upper end side.

By performing the above operation, the indicated value of the flow meter 14 reaches the volume of the conduit 3 or the exhaust from the vent valve 39 contains dry ice snow, etc. When it can be confirmed that the gas is charged, the operation moves to the discharge operation of liquid carbon dioxide by the carbon dioxide discharge device 1 as described below.
Specifically, the vent valve 39 of the exhaust device 36 is closed to restrict the discharge of the fluid in the conduit 3 through the exhaust passage 37, and in this state, the large-capacity LCO ₂ pump 13a of the liquid carbon dioxide supply device 2 is turned on. By operating, liquid carbon dioxide is supplied into the outer pipe W2 and discharged from the nozzle 3.
Here, the liquid carbon dioxide supply device 2 may supply the liquid carbon dioxide to the nozzle 3 not only through the outer pipe W2 but also through the inner pipe W1.

On the other hand, when each pipe constituting the inner pipe W1 of the conduit 3 and each pipe constituting the outer pipe W2 are sequentially connected while being filled with seawater, Since seawater has invaded, a purge operation in the conduit 3 is performed prior to the supply of liquid carbon dioxide into the conduit 3.
Hereinafter, the purge operation in the conduit 3 in this case will be described.

  First, the seawater in the conduit 3 is discharged. Specifically, with the exhaust pump 38 of the exhaust device 36 stopped and the vent valve 39 closed, the first valve 26 and the second valve 27 of the purge gas supply device 21 are opened, and the compressor 3 causes the conduit 3 to open. The purge gas is supplied from the upper end into the inner pipe W1 and the outer pipe W2. The supply pressure of the purge gas at this time is a pressure equal to or higher than the seawater pressure (about 100 atm) applied to the lower end of the conduit 3.

  By supplying the purge gas into the conduit 3 from the upper end in this way, the seawater in the conduit 3 is pushed down by the purge gas and pushed out from the lower end of the conduit 3. As a result, the inside of the conduit 3 is replaced with a high-pressure purge gas of about 100 atm.

Next, the purge gas in the conduit 3 is replaced with liquid carbon dioxide.
Specifically, first, the first valve 26 and the second valve 27 of the purge gas supply device 21 are closed to prevent the reverse flow of the purge gas from the conduit 3 to the purge gas supply line 23, and then the vent valve 39 of the exhaust device 36. And the internal pressure of the outer pipe W2 is reduced to a pressure slightly exceeding the pressure range in which carbon dioxide is converted to dry ice. In the present embodiment, the internal pressure of the outer conduit W2 is reduced to 10 kg / cm ² .
Thereafter, by supplying liquid carbon dioxide from the upper end into the inner pipe line W1 at a pressure exceeding the internal pressure of the outer pipe line W2, the purge gas in the conduit 3 is replaced with liquid carbon dioxide.

  As described above, in the carbon dioxide discharge apparatus 1, the purge gas in the conduit 3 can be taken out from the upper end, so that the liquid dioxide used for the replacement of the purge gas in the conduit 3 can be compared with the case where the purge gas is pushed out from the lower end of the conduit 3. The supply pressure of carbon can be significantly reduced. For this reason, less power is required to replace the purge gas in the conduit 3, and further generation of carbon dioxide can be suppressed.

Further, in the present embodiment, the conduit 3 towed by the ship is configured such that the inner tube 17 is inserted into the outer tube 16.
As a result, only the outer pipe 16 is exposed to the sea, and the resistance generated in the pipe 3 during towing can be reduced, and seawater pressure is not applied to the inner pipe 17, so that the outer pipe 16 and the inner pipe 17 are required. The strength level produced is low and the manufacturing cost is low.
Furthermore, since the inner tube 17 can be extracted from the sea to the outside of the outer tube 16, maintenance is easy when the inner tube 17 is clogged.

  Here, at a depth of several hundred meters, the seawater temperature is about 5 ° C., which is close to the seawater temperature around the lower end of the conduit 3. For this reason, in the carbon dioxide discharge apparatus 1 shown in the present embodiment, as shown in FIG. 2, the inner pipe 17 is not provided up to the lower end of the outer pipe 16, and the inner pipe has a length reaching several hundreds of meters. The same effect as when 17 is provided up to the lower end of the outer tube 16 can be expected.

Further, in the present embodiment, when the used purge gas in the conduit 3 is removed, the pressure of the purge gas in the outer pipe line W2 is set to a pressure range in which carbon dioxide is converted to dry ice (4.25 kg / cm in gauge pressure). ² ) Although the pressure is higher than that, the inner pressure of the outer pipe W2 is kept slightly higher than the vapor pressure of carbon dioxide (70 to 80 kg / cm ² abs near 20 ° C) without being limited thereto. Thus, since the liquid carbon dioxide supplied into the conduit 3 is kept in a liquid phase, the pressure maintaining device 31 can be omitted.

  Moreover, in the said embodiment, although the example which used the conduit | pipe 3 comprised by the outer tube | pipe 16 and the inner tube | pipe 17 as a conduit | pipe which supplies liquid carbon dioxide to the nozzle 4 was shown, it is not restricted to this, A conduit | pipe Instead of 3, a double pipe (that is, an internal pipe W1 and an external pipe W2 are integrally formed with an internal pipe W1 provided radially inside and an external pipe W2 provided radially outside. May be used.

Further, instead of using the conduit 3 constituted by the outer pipe 16 and the inner pipe 17, as shown in FIG. 3, it is constituted by a first pipe W3 and a second pipe W4 provided independently of each other. A conduit 40 is provided, the liquid carbon dioxide supply device 2 and the purge gas supply device 21 are connected to the upper end of the first pipe W3, and the exhaust device 36 is connected to the upper end of the second pipe W4. .
Here, the first pipeline W3 may be connected to the vicinity of the lower end of the second pipeline W4 as shown by a solid line in FIG. 3, and the depth number as shown by a two-dot chain line in FIG. It may be connected to the second pipe line W4 at a position of 100 m.

Moreover, in the said embodiment, although the structure which uses the purge gas in the storage tank 22 was shown as purge gas, it is not restricted to this, For example, dry air obtained by dehumidifying a marine atmosphere as purge gas is shown. It is good also as a structure to use.
In this case, instead of the purge gas supply device 21, a purge gas supply device 41 shown in FIG. The purge gas supply device 41 includes, on the purge gas supply path 23, a compressor 24 that compresses outside air (sea atmosphere), and a dehumidification device 42 that removes moisture from the compressed air compressed by the compressor 24 to obtain dry air. It is set as the provided structure. For example, a heater or a dryer is used as the dehumidifying device 42.
Thus, by using the dry air obtained from the marine atmosphere as the purge gas, the storage tank 22 becomes unnecessary, and the equipment can be downsized. Further, the use amount of the purge gas due to the capacity of the storage tank 22 is eliminated.

Moreover, you may use the carbon dioxide gas obtained by vaporizing the liquid carbon dioxide in the storage tank 11 of the liquid carbon dioxide supply apparatus 2 as purge gas.
In this case, instead of the purge gas supply device 21, a purge gas supply device 46 shown in FIG. The purge gas supply device 46 has a heater 47 for heating and vaporizing the liquid carbon dioxide supplied from the storage tank 11 on the purge gas supply path 23, and a compressor 24 for compressing the carbon dioxide gas vaporized by the heater 47. It is set as the structure provided.
Thus, by using the carbon dioxide gas obtained by vaporizing the liquid carbon dioxide in the storage tank 11 as the purge gas, the storage tank 22 becomes unnecessary, and the equipment can be small. Further, the use amount of the purge gas due to the capacity of the storage tank 22 is eliminated.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The carbon dioxide discharge device 51 according to the present embodiment is provided with a purge gas recovery device 52 for recovering the purge gas supplied into the conduit 3 in addition to the configuration of the carbon dioxide discharge device 1 shown in the first embodiment. Is the main feature.
Hereinafter, the same or the same configuration as that of the carbon dioxide discharge apparatus 1 shown in the first embodiment is indicated by the same reference numeral, and detailed description thereof is omitted.

  The purge gas recovery device 52 includes a recovery conduit 53 that connects the upper end of the outer conduit W2 and the storage tank 22 of the purge gas supply device 21, a valve 54 provided on the recovery conduit 53, a valve 54, and the storage tank 22. And a compressor 55 provided between the two.

In the carbon dioxide discharge device 51 configured as described above, the valve 54 is normally closed, and when the purge gas used for purging in the conduit 3 is replaced with liquid carbon dioxide, the vent valve 39 is not opened. 54 is opened, and the purge gas in the conduit 3 is fed into the recovery conduit 53 instead of the exhaust passage 37.
The purge gas sent into the recovery line 53 is sent into the storage tank 22 in a state of being pressurized to a pressure higher than the internal pressure of the storage tank 22 by being compressed by the compressor 55, and used for the next use. The

  In the liquid carbon dioxide supply device 51 configured as described above, since the purge gas can be reused, the cost required for the carbon dioxide discharge operation can be reduced. Further, the use amount of the purge gas due to the capacity of the storage tank 22 is eliminated.

[Third embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS.
The carbon dioxide discharge device 61 according to this embodiment is the same as the carbon dioxide discharge device 1 shown in the first embodiment, except that the plug insertion portion 62 is provided in the carbon dioxide supply path 12 of the liquid carbon dioxide supply device 2, and Instead, the main feature is that a conduit 64 having a plug recovery part 63 is provided.
Hereinafter, the same or the same configuration as that of the carbon dioxide discharge apparatus 1 shown in the first embodiment is indicated by the same reference numeral, and detailed description thereof is omitted.

  The plug insertion portion 62 is provided on the downstream side of the flow meter 14 in the carbon dioxide supply path 12, and as shown in FIG. 8, the first unit constituting the flow meter 14 side in the carbon dioxide supply path 12. 66, the second unit 67 that constitutes the connection end side of the carbon dioxide supply path 13 to the conduit 64 and is detachably connected to the first unit 66, and the second unit 67 and the conduit 64 are connected. In addition, it has a connecting pipe line 68 whose inner diameter is substantially the same as the inner diameter of the inner pipe 71 described later.

The first unit 66 has an enlarged diameter portion 66a at the connection end with the second unit 67, and a flange 66b is provided on the periphery of the open end of the enlarged diameter portion 66a.
The second unit 67 has an enlarged diameter portion 67a at the connection end with the first unit 66, and a flange 67b is provided on the periphery of the open end of the enlarged diameter portion 67a.
The first unit 66 and the second unit 67 are detachably connected by bolting the flanges 66b and 67b in a state where the opening ends of each other are abutted. In a state in which the first unit 66 and the second unit 67 are connected, these connecting portions are hermetically and liquid-tightly sealed.

Further, in the carbon dioxide supply path 12, valves 69 are provided at positions near the upstream side of the first unit 66 and positions near the downstream side of the second unit 67, respectively. The space in the enlarged diameter portions 66 a and 67 a in the second units 66 and 67 can be isolated from the carbon dioxide supply path 12.
In the second unit 67, a plug that can move in the connection pipe 68 and the inner pipe 71 while partitioning the connection pipe 68 and the inner pipe 71 in an airtight and liquid-tight manner is connected to the connection pipe 68. 70 is inserted.

As shown in FIG. 7, the conduit 64 has an outer tube 16 and an inner tube 71 inserted into the outer tube 16. Here, the inner pipe W1 is constituted by the inner pipe 71, and the outer pipe W2 is constituted by the pipe constituted by the outer pipe 16 and the inner pipe 71.
The inner pipe 71 is formed by connecting a plug recovery portion 63 to the lower end of a pipe body 71a having the same diameter over the entire length.

  As shown in FIG. 9A, the plug recovery part 63 forms a lower end part of the first unit 72 provided on the pipe body 71a side and the inner pipe 71 and is detachably connected to the first unit 72. Second unit 73.

The first unit 72 has an enlarged diameter portion 72a having a diameter larger than that of the plug 70 at the connection end with the second unit 73, and a flange 72b is provided at the periphery of the opening end of the enlarged diameter portion 72a. Yes.
The second unit 73 has an enlarged diameter portion 73a having a diameter larger than that of the plug 70 at the connection end with the first unit 72, and a flange 73b is provided at the periphery of the opening end of the enlarged diameter portion 73a. Yes.
The first unit 72 and the second unit 73 are detachably connected by bolting the flanges 72b and 73b in a state where the opening ends of each other are abutted. In a state where the first unit 72 and the second unit 73 are connected, these connecting portions are sealed in an airtight and liquid-tight manner.

In the second unit 73, a reduced diameter portion 73 c is provided on the lower end side of the inner tube 71.
The reduced diameter portion 73c is provided with a stopper 74 that restricts passage of the plug 70 while allowing passage of fluid. In the present embodiment, as shown in FIG. 9 (b), the stopper 74 is a cross-shaped substantially cross member fixedly inserted into the reduced diameter portion 73c, and the inner peripheral surface of the reduced diameter portion 73c. A gap that is smaller than the plug 70 is formed between the two and the fluid, and the passage of fluid through the gap is allowed.

  In the carbon dioxide discharge device 61 configured as described above, the purge operation in the conduit 64 is performed in the same procedure as the carbon dioxide discharge device 1 shown in the first embodiment, but the purge gas in the conduit 64 is liquid. The operation of substituting for carbon dioxide is performed according to the following procedure.

First, in a state in which the purge gas is filled in the conduit 64, the valves 69 and 69 of the carbon dioxide supply path 12 are closed, and the diameter-expanded portions 66a and 66a in the first and second units 66 and 67 of the plug insertion portion 62 are closed. The space in 67 a is isolated from the carbon dioxide supply path 12.
In this state, the first and second units 66 and 67 are separated, and the plug 70 is inserted into the connection portion with the connection pipe line 68 in the second unit 67.

Liquid carbon dioxide is supplied into the conduit 64 from the liquid carbon dioxide supply device 2 with the first and second units 66 and 67 connected again and the valves 69 and 69 opened.
As a result, the plug 70 receives the supply pressure of liquid carbon dioxide and is moved downward in the connection pipe 68 and the inner pipe 71 of the conduit 64.
Since the plug 70 partitions the inside of the connection pipe 68 and the inside of the inner pipe 71 in an airtight / liquid tight manner, the purge gas in the inner pipe 71 is pushed downward by moving the plug 70 downward in this way. And is discharged from the lower end of the inner pipe 71.

When the plug 70 is further moved and reaches the plug collecting portion 63 provided at the lower end of the tube main body 71a, the plug 70 is discharged into the space formed by the enlarged diameter portions 72a and 73a.
In this space, the plug 70 is released from restraint by the inner surface of the pipe body 71a, so that liquid carbon dioxide is supplied to the lower end of the inner pipe 71 through the gap between the plug 70 and the enlarged diameter portions 72a and 73a. . Moreover, since the stopper 74 is provided in the reduced diameter part 73c which is an exit of this space, the plug 70 is hold | maintained in the plug collection | recovery part 73, without being lowered | hung any more.
Thereafter, by supplying liquid carbon dioxide to the inner pipe 71 by the liquid carbon dioxide supply device 2, liquid carbon dioxide is sent from the lower end of the inner pipe 71 into the outer pipe W2, and the inside of the conduit 64 is liquid. Replaced by carbon dioxide.

  As described above, in the carbon dioxide discharge device 61, the purge gas and the liquid carbon dioxide in the inner pipe 71 are replaced while the purge gas and the liquid carbon dioxide in the inner pipe 71 are separated. The liquid carbon dioxide does not flow under the purge gas in the pipe 71, and the replacement can be performed efficiently.

  Further, since the conduit 64 is constituted by the outer tube 16 and the inner tube 71 that is inserted into the outer tube 16 so that it can be pulled out, the plug 64 can be obtained by pulling the inner tube 71 from the outer tube 16 to the sea. The plug 70 collected in the collection unit 63 can be collected, and the inner pipe 71 and the plug 70 can be reused.

Here, in this embodiment, instead of using the conduit 64 constituted by the outer tube 16 and the inner tube 71, as shown in FIG. 10, the first conduit W5 and the second tube provided independently of each other, as shown in FIG. You may use the conduit | pipe 81 comprised by the path W6.
Specifically, as the conduit 81, a first conduit W5 to which the liquid carbon dioxide supply device 2 and the purge gas supply device 21 are connected at the upper end and a second conduit W6 to which the exhaust device 36 is connected at the upper end are provided. Then, the lower end of the first pipeline W5 is connected to the second pipeline W6, and the plug insertion portion 62 and the plug recovery portion 63 are provided in the first pipeline W5.

Also in this case, the purge gas and the liquid carbon dioxide in the first pipe line W5 are replaced while the purge gas and the liquid carbon dioxide in the first pipe line W5 are separated. It can be carried out.
Here, the first pipeline W5 may be connected to the vicinity of the lower end of the second pipeline W6 as shown by a solid line in FIG. 10, and the depth number as shown by a two-dot chain line in FIG. It may be connected to the second pipeline W6 at a position of 100 m.

It is a figure which shows the structure of the carbon dioxide discharge apparatus concerning 1st embodiment of this invention. It is a figure which shows the other structural example of the carbon dioxide discharge apparatus concerning 1st embodiment of this invention. It is a figure which shows the other structural example of the carbon dioxide discharge apparatus concerning 1st embodiment of this invention. It is a figure which shows the other structural example of the carbon dioxide discharge apparatus concerning 1st embodiment of this invention. It is a figure which shows the structure of the carbon dioxide discharge apparatus concerning 2nd embodiment of this invention. It is a figure which shows the other structural example of the carbon dioxide discharge apparatus concerning 2nd embodiment of this invention. It is a figure which shows the structure of the carbon dioxide discharge apparatus concerning 3rd embodiment of this invention. It is a figure which shows the structure of the carbon dioxide discharge apparatus concerning 3rd embodiment of this invention. It is a figure which shows the structure of the carbon dioxide discharge apparatus concerning 3rd embodiment of this invention, Comprising: (a) is a longitudinal cross-sectional view, (b) is an AA arrow directional cross-sectional view of (a). It is a figure which shows the other structural example of the carbon dioxide discharge apparatus concerning 3rd embodiment of this invention.

Explanation of symbols

1, 51, 61 Carbon dioxide discharge device 2, 46 Liquid carbon dioxide supply device 3, 40, 63 Conduit 4 Nozzle 5 Check valve 16 Outer pipe 17, 71 Inner pipe 31 Pressure maintenance device 36 Exhaust device 52 Purge gas recovery device 63 Plug Collection part 70 Plug W1 Internal pipe line W2 External pipe line W3 First pipe line W4 Second pipe line W5 First pipe line W6 Second pipe line

Claims (7)

A carbon dioxide discharge device for discharging liquid carbon dioxide supplied from a liquid carbon dioxide supply device at sea into the sea,
A conduit suspended from the sea and supplied with the liquid carbon dioxide from the upper end by the liquid carbon dioxide supply device;
A nozzle connected to the lower end of the conduit;
A check valve interposed between the lower end of the conduit and the nozzle to prevent backflow of fluid from the nozzle into the conduit;
The conduit is constituted by a plurality of pipelines,
As the conduit, a double pipe provided with an internal pipe line on the radially inner side and an external pipe line on the radially outer side is used,
Some of the pipes have lower ends connected to other pipes,
A carbon dioxide discharge device, wherein an exhaust device is connected to an upper end of the other pipe.   2. The carbon dioxide discharge device according to claim 1, wherein the conduit is constituted by an outer tube and an inner tube inserted in the outer tube so as to be able to be extracted. The lower end of the portion of the conduit may dioxide according to the internal pressure of the portion of the conduit, to claim 1 or 2, characterized in that it is configured to maintain a pressure of greater than or equal to the vapor pressure of carbon dioxide Carbon discharge device. In the part of the pipes, a plug that partitions the inside of the part of the pipes in an airtight and liquid-tight manner and is movable to a lower end side;
The carbon dioxide discharge according to any one of claims 1 to 3 , further comprising a plug recovery portion provided in the vicinity of a lower end of the part of the pipes and having an inner diameter larger than a diameter of the plug. apparatus. The carbon dioxide discharge device according to any one of claims 1 to 4 , wherein the exhaust device has a purge gas recovery device that recovers unnecessary gas discharged from the inside of the conduit. A carbon dioxide discharge method for supplying liquid carbon dioxide from a liquid carbon dioxide supply device at sea to a conduit suspended from the sea into the sea, and discharging liquid carbon dioxide from a nozzle provided at the lower end of the conduit into the sea,
The conduit is constituted by a plurality of pipelines;
The conduit is constituted by a double pipe in which an inner pipe line is provided on the radially inner side and an outer pipe line is provided on the radially outer side,
Prior to discharge working of the liquid carbon dioxide, wherein a portion of the conduit, by supplying fluid from the upper end, the unwanted gas in said portion of the conduit and the other conduit in the fluid The carbon dioxide release method characterized by substituting. A carbon dioxide discharge method for supplying liquid carbon dioxide from a liquid carbon dioxide supply device at sea to a conduit suspended from the sea into the sea, and discharging liquid carbon dioxide from a nozzle provided at the lower end of the conduit into the sea,
The conduit is constituted by a plurality of pipelines;
As the conduit, an outer tube that forms the conduit, and an inner tube that forms the conduit that is inserted into the outer tube so as to be extractable,
A part of the pipes has a lower end connected to the other pipes,
Prior to discharge working of the liquid carbon dioxide, wherein a portion of the conduit, by supplying fluid from the upper end, the unwanted gas in said portion of the conduit and the other conduit in the fluid The carbon dioxide release method characterized by substituting.

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