JP4274817B2 - Gas hydrate storage tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas hydrate storage tank for storing a so-called gas hydrate composed of a gas mainly composed of methane such as natural gas and water.
[0002]
[Prior art]
Conventionally, natural gas is transported and stored in the form of liquefied natural gas (LNG) or compressed natural gas (CHG).
[0003]
By the way, since LNG needs to be transported or stored while keeping the cargo temperature at minus 162 ° C., an expensive tank is required for transport and storage. In addition, it requires a lot of energy for its manufacture, and if the temperature control is not good, it rapidly vaporizes, which is very dangerous. Furthermore, as described above, since the temperature is extremely low, the vaporization rate is high and it is not suitable for long-term storage.
[0004]
Therefore, in recent years, gas hydrate (hereinafter referred to as NGH) composed of a gas mainly composed of methane such as natural gas and water has attracted attention as a clean energy source and raw materials of various structures. Means for manufacturing and transportation have been proposed (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
JP 2000-304196 A (page 2-3, FIG. 1)
[0006]
[Problems to be solved by the invention]
By the way, it is necessary to store NGH once in the manufacturing site of NGH, a transit route, or a consumption place. A storage tank for storing NGH needs to be large and economical to manufacture from an economical aspect. Recently, development of an NGH storage tank considering this point has been strongly desired by the industry. is there.
[0007]
[Means for Solving the Problems]
The present invention has been made in view of such a situation, and a plurality of partition walls are arranged in a tank body covered with a heat insulating material so as to have a predetermined interval to constitute a plurality of unit tanks. The bottom of the unit tank has a funnel shape, and a discharge port connected to the discharge device is provided below the unit tank. Further, a temperature sensor is provided in each unit tank, and a cooling / heating medium and gas hydrate carry-in port is provided. In the gas hydrate storage tank that controls the supply amount of the cooling / heating medium by introducing a temperature signal of the sensor into the control device, each partition wall is provided with a communication hole having an opening / closing valve, and a predetermined unit tank is cooled. - connected to the temperature medium supply system, the gas hydrate storage tank, characterized in that for supplying the cold-temperature medium supplied to the unit tank to another unit tank through the communication hole It is an do subjected.
[0008]
Thus, according to the present invention, since a plurality of unit tanks are formed in the tank main body and the bottom surface thereof is configured in a funnel shape, not only can the NGH be easily discharged, but also the dead at the bottom of the tank main body. Space can be reduced. As a result, the storage amount in the NGH in the storage tank can be increased.
[0009]
A plurality of unit tanks are configured to be supplied with a gas hydrate and a cooling / heating medium, respectively, and a supply amount of the cooling / heating medium is provided by a temperature sensor disposed in each unit tank. Since each unit tank is maintained at a predetermined temperature, workability when carrying in gas hydrate can be improved, and stable storage of gas hydrate over a long period of time is possible. Become.
[0011]
In addition, as described above, the present invention is provided with a communication hole having an on-off valve in each partition wall, and a predetermined unit tank is connected to a cooling / heating medium supply facility so that the cooling / heating temperature supplied to the unit tank is reduced. In order to supply the medium to the other unit tank via the communication hole , the predetermined unit tank is first brought to a predetermined temperature, for example, about minus 25 ° C. by the cold / hot medium supplied from the cold / hot medium supply facility. After cooling, an on-off valve provided in a partition wall between the unit tank and the adjacent unit tank is opened to supply a cooling / heating medium to the adjacent unit tank. Thereafter, this operation is sequentially repeated to sequentially cool the unit tanks to a predetermined temperature. As a result, since the NGH can be loaded into the predetermined unit tank when the predetermined unit tank is cooled to the predetermined temperature, the efficiency of the NGH loading work can be improved.
[0012]
(2) Further , the gas hydrate storage tank of the present invention includes a cold / hot medium supply pipe having one end connected to the cold / hot medium supply facility so as to be positioned in each unit tank, and · the temperature medium feed pipe provided with a discharge port having an on-off valve in each unit tank, further, the feature that by controlling the opening and closing valve by the control signal of the control device supplying a heating medium to the predetermined unit tank To do.
[0013]
According to such a configuration, the selected unit tank among the plurality of unit tanks constituting the storage tank main body is cooled as the first unit tank, and NGH is carried into the selected arbitrary unit tank. Therefore, the workability of the NGH loading work can be further improved.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a gas hydrate storage tank according to the present invention, and FIG. 2 is a view taken along the line AA ′ of FIG.
[0019]
As shown in FIG. 1, the tank body 1 of the gas hydrate storage tank 100 includes an inner wall 2, a heat insulating material 3 covering the inner wall 2, and an outer wall 4 surrounding the heat insulating material 3. In the interior, a plurality of partition walls 5a, 5b, 5c are arranged at predetermined intervals, and a plurality of unit tanks (unit tanks) 6a, 6b, 6c, 6d are formed. The upper parts of the unit tanks 6a, 6b, 6c, 6d are supported by the support column 30. The support column 30 is connected to the inner wall 2 and the partition wall 5 by a fastener 31 such as a tie rod.
[0020]
The bottom surface 7 constituting a part (bottom part) of the unit tanks 6a, 6b, 6c, 6d is formed in a funnel shape having an inclination angle equal to or larger than the angle of repose of NGH. Discharge ports 9 a, 9 b, 9 c, 9 d ˜ having opening / closing valves (not shown) are provided at the bottom of the bottom surface 7. The inclination angle of the funnel-shaped bottom surface 7 is appropriately set according to the state of the NGH so that the stored NGH is automatically discharged from the discharge ports 9a, 9b, 9c, 9d when the on-off valve is opened. . That is, NGH may be stored in the form of a sherbet, powder, pellet, or slurry using antifreeze, and these NGHs have different repose angles.
[0021]
The partition walls 5a, 5b, 5c˜ have communication holes 10a, 10b, 10c˜ having opening / closing valves 11a, 11b, 11c˜ at their upper portions, and the unit tanks are opened by opening the opening / closing valves 11a, 11b, 11c˜. 6a, 6b, 6c, 6d are communicated. For example, cold air or hot air A is supplied to the most upstream unit tank 6a from a cold / hot medium supply facility 12 such as an air conditioner.
[0022]
In the figure, 14a, 14b, 14c, 14d~ the unit tank 6a, 6b, 6c, a temperature sensor is disposed within 6D～, the temperature signal _{V 1, V 2, V 3} , V 4 ~ control The on / off valves 11a, 11b, and 11c are respectively controlled by control signals V ₁₁ , V ₁₂ , V ₁₃ ,. Each of the unit tanks 6a, 6b, 6c, 6d is provided with a pressure adjusting discharge valve (not shown) at the top thereof.
[0023]
In the figure, 16 is an NGH supply pipe, and NGH 18 can be carried into predetermined unit tanks 6a, 6b, 6c, 6d˜ by opening / closing on-off valves 17a, 17b, 17c, 17d˜. Reference numeral 19 denotes a carry-out device disposed below the unit tanks 6a, 6b, 6c, and 6d. Depending on the state of the NGH, for example, a belt conveyor, a screw conveyor, a slurry pipe, or the like is used. Moreover, the carrying-out apparatus 19 is coat | covered with the heat insulating material 3 as needed.
[0024]
Next, the case where NGH is carried into a gas hydrate storage tank and stored will be described.
[0025]
As shown in FIG. 3, first, the cold / hot medium supply facility 12 is activated to supply, for example, cold air A of −25 ° C. to −10 ° C. into the uppermost unit tank 6a. At this time, the on-off valve (not shown) of the discharge port 9a and the on-off valve 11a of the partition wall 5a are closed. In this case, the pressure in the unit tank 6a increases, but the pressure increase can be prevented by the action of a discharge valve (not shown).
[0026]
When the inside of the unit tank 6a reaches a predetermined temperature (for example, minus 20 ° C.), the opening / closing valve 17a of the NGH supply pipe 16 is opened, and the NGH 18 is carried into the unit tank 6a, and at the same time, the opening / closing valve 11b of the partition wall 5b is opened. The unit tank 6b is opened and cool air A is introduced into the unit tank 6b to cool the inside of the unit tank 6b to a predetermined temperature.
[0027]
When a predetermined amount of NGH 18 is carried into the unit tank 6a, the on-off valve 17a is closed and the on-off valve 17b is opened to carry the NGH 18 into the unit tank 6b.
[0028]
Thereafter, the NGH 18 is sequentially carried into the unit tanks 6c, 6d to be stored by the same method. In this case, the control of the on-off valves 17a, 17b, 17c, and 17d is performed by a control signal from the control device 15.
[0029]
As described above, in carrying in and storing NGH, the carrying-in work can be started by cooling only the uppermost unit tank 6a to a predetermined temperature without cooling the entire tank main body 1. Work efficiency can be improved.
[0030]
The NGH 18 stored in the unit tank bodies 6a, 6b, 6c, 6d is stored while being cooled to a certain temperature for a predetermined period. The cooling temperature (cold temperature) is preferably -25 ° C to -10 ° C. That is, it is known that natural gas hydrate (NGH) containing methane as a main component is usually stable at normal pressure by setting the temperature to -25 ° C to -10 ° C.
[0031]
Therefore, the inside of each unit tank main body 6a, 6b, 6c, 6d-can be made into a normal pressure by cooling and storing to the said temperature. This means that the unit tank bodies 6a, 6b, 6c, 6d, in other words, the tank body 1 does not need to be a pressure-resistant shell, and the structure can be light. As a result, the tank body 1 can be manufactured at low cost. Of course, when the temperature in each unit tank 6a, 6b, 6c, 6d ~ comes out of a predetermined range during the storage process, the temperature is detected by the temperature sensors 14a, 14b, 14c, 14d ~ The hot medium supply facility 12 is controlled.
[0032]
Next, the case where the NGH 18 stored in the unit tanks 6a, 6b, 6c, 6d is carried out will be described.
[0033]
When carrying out the NGH 18 in the unit tank 6a, as shown in FIG. 4, when the opening / closing valve (not shown) of the discharge port 9a is opened, the NGH 18 in the unit tank 6a is discharged from the discharge port 9a by its own weight. It falls down and is discharged. At this time, by supplying the cool air A into the unit tank 6a by the heat medium supply facility 12, it is possible to prevent the internal pressure from decreasing and maintain the cooling temperature.
[0034]
The NGH 18 can be carried out arbitrarily from any of the unit tanks 6a, 6b, 6c, 6d. In that case, the on / off valves 11a, 11b, and 11c may be appropriately operated to supply the cold air A to the selected unit tanks 6a, 6b, 6c, and 6d.
[0035]
FIG. 5 is a cross-sectional view of the second embodiment of the gas hydrate storage tank. The same components as those of the first embodiment already described are denoted by the same reference numerals and detailed description thereof is omitted.
[0036]
In this embodiment, a cold / hot medium supply pipe 20 connected to the cold / hot medium supply facility 12 is disposed at the lower part of the tank body 1. The cold / hot medium supply pipe 20 is provided with discharge ports 22a, 22b, 22c, 22d˜ having opening / closing valves 21a, 21b, 21c, 21d˜ for each unit tank 6a, 6b, 6c, 6d˜. ing.
[0037]
On the other hand, an NGH supply pipe 23 is provided above the unit tanks 6a, 6b, 6c, 6d,. The NGH supply pipe 23 is also provided with supply ports 25a, 25b, 25c, 25d˜ having opening / closing valves 24a, 24b, 24c, 24d˜ for each unit tank 6a, 6b, 6c, 6d˜. Here, 26a, 26b, and 26c are fans provided in the communication holes 10a, 10b, and 10c.
[0038]
In the case of this example, one or more of the selected unit tanks 6a, 6b, 6c, 6d can be simultaneously cooled by opening any of the on-off valves 21a, 21b, 21c, 21d. . Then, by opening the on-off valves 24a, 24b, 24c, 24d˜ of the corresponding unit tanks 6a, 6b, 6c, 6d˜, the NGH 18 is carried in and stored in the cooled unit tanks 6a, 6b, 6c, 6d˜. can do. Further, by operating the fans 26a, 26b, 26c˜ as necessary, the unit tanks 6a, 6b, 6c, 6d˜ can be ventilated quickly.
[0039]
When cracked gas is generated, a pressure sensor (not shown) is installed for each unit tank 6a, 6b, 6c, 6d, and each unit tank 6a, 6b is based on a signal from each pressure sensor. , 6c, 6d, etc. are operated to release on-off valves (not shown) from the unit tanks 6a, 6b, 6c, 6d to the outside of the unit tanks. Of course, the cracked gas may be led to an NGH production apparatus (not shown) if necessary, and stored again as NGH 18.
[0040]
In the above-described embodiment, the case where the unit tanks 6a, 6b, 6c, and 6d are arranged in the horizontal direction is shown. However, the unit tank 6 may be joined in the vertical and horizontal directions as shown in FIG. . Reference numerals 6a, 6b, 6c to 60a, 60b, 60c denote unit tanks. This arrangement is particularly suitable when the tank body 1 is large.
[0041]
Further, by providing a heat insulating material in the partition walls 5a, 5b, 5c, for example, when discharging NGH 18 from a specific unit tank, only the unit tank storing NGH 18 may be cooled to a predetermined temperature. The required energy can be reduced.
[0042]
When decomposing NGH, hot air is used by switching the cold / hot medium supply facility 12. And NGH is decomposed | disassembled in the storage tank 100, and natural gas is taken out. Further, when the storage tank 100 is maintained and inspected, warm air is required to remove the remaining NGH.
[0043]
【The invention's effect】
As described above, the present invention configures a plurality of unit tanks by arranging a plurality of partition walls with a predetermined interval in a tank body covered with a heat insulating material, and the bottom surface of each unit tank has a funnel shape. In addition, a discharge port connected to the discharge device is provided at the bottom, and a temperature sensor is provided in each unit tank, and a cold / hot medium and gas hydrate carry-in port is provided. Since the introduction of the cooling / heating medium is controlled by introduction, it is easy to maintain a predetermined temperature in each unit tank, improving workability when carrying in NGH, and stable over a long period of time. NGH can be stored.
[0044]
Moreover, since temperature control in each unit tank is performed, NGH can be stored at normal pressure. As a result, the storage tank body can be lightly structured, and the storage tank body can be constructed at a low cost.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an example of a gas hydrate storage tank according to the present invention.
FIG. 2 is a cross-sectional view taken along the line AA ′ in FIG.
FIG. 3 is an explanatory diagram for carrying in gas hydrate.
FIG. 4 is an explanatory view of the discharge of gas hydrate.
FIG. 5 is a schematic sectional view showing another example of the gas hydrate storage tank according to the present invention.
FIG. 6 is a perspective view showing still another example of the gas hydrate storage tank according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tank main body 2 Inner wall 3 Heat insulating material 4 Outer wall 5a, 5b, 5c Partition wall 6a, 6b, 6c, 6d Unit tank 7 Bottom surface 9a, 9b, 9c, 9d Discharge port 10a, 10b, 10c Communication hole 11a, 11b, 11c, 17a , 17b, 17c, 17d, 21a, 21b, 21c, 21d On-off valve 12 Heat medium supply equipment 14a, 14b, 14c, 14d Temperature sensor 15 Controller 16 NGH supply pipe 18 NGH
19 Discharge device 20 Heat medium supply pipe 22a, 22b, 22c, 22d Discharge port 23 Supply pipe 30 Strut 31 Fastening material

Claims (2)

A plurality of partition tanks are arranged in a tank body covered with a heat insulating material so as to have a predetermined interval, and a plurality of unit tanks are formed. A bottom surface of each unit tank is formed in a funnel shape and is connected to a discharge device at a lower portion thereof In addition, a temperature sensor is disposed in each unit tank, and a cooling / heating medium and gas hydrate carry-in port is provided. A temperature signal of the temperature sensor is introduced into the control device, and the cooling / heating medium In the gas hydrate storage tank for controlling the supply amount, each of the partition walls is provided with a communication hole having an opening / closing valve, and a predetermined unit tank is connected to a cooling / heating medium supply facility so that the cooling water supplied to the unit tank can be controlled. A gas hydrate storage tank , wherein a warm medium is supplied to another unit tank through the communication hole . A plurality of partition tanks are arranged in a tank body covered with a heat insulating material so as to have a predetermined interval, and a plurality of unit tanks are formed. A bottom surface of each unit tank is formed in a funnel shape and is connected to a discharge device at a lower portion thereof In addition, a temperature sensor is disposed in each unit tank, and a cooling / heating medium and gas hydrate carry-in port is provided. A temperature signal of the temperature sensor is introduced into the control device, and the cooling / heating medium In the gas hydrate storage tank for controlling the supply amount, a cold / hot medium supply pipe having one end connected to a cold / hot medium supply facility is extended so as to be located in each unit tank, and the cold / hot medium is the supply pipe provided with a discharge port having an on-off valve in each unit tanks, further to said the supplies heat medium by controlling the on-off valve to a predetermined unit tank by the control signal of the control device Ruga Suhai Rate storage tank.

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