JP5091746B2 - Gas hydrate gasifier - Google Patents

Description

  In the present invention, granular gas hydrate stored at low pressure such as under atmospheric pressure is transferred into a high-pressure gasification tank containing a liquid such as water, and the hydrate is decomposed and gasified. The present invention relates to a gas hydrate gasifier.

Gas hydrates such as natural gas hydrate are pelletized (granular) and are usually stored under atmospheric pressure.
As a main utilization method of the gas hydrate after gasification, a fuel for power generation and a city gas raw material are considered, and a high pressure of 3.5 MPa or more is required for the power generation fuel and 5.0 MPa or more is required for the city gas raw material. Since the gas hydrate has a characteristic that a high-pressure gas can be obtained without relying on a power machine for its physical properties, high-pressure gasification utilizing the characteristic is possible.

  In order to gasify this gas hydrate, it is necessary to transfer the gas hydrate stored under the atmospheric pressure into a gasification tank under high pressure. Examples of conventional techniques for press-fitting into a high-pressure gasification tank include a ball batch system (Patent Document 1 and the like) and a high-pressure seal type rotary feeder system.

  However, the conventional press-fitting method has a structure in which gas hydrate is introduced from the gas phase side above the gasification tank. Therefore, it is necessary to transfer the gas hydrate under atmospheric pressure to the intermediate container once and pressurize the intermediate container to the same level or higher as in the gasification tank in a state where the intermediate container is pressure-blocked from the outside. In that case, since the inside of the intermediate container is in a state where gas exists in the gaps between the granular gas hydrates, there is a problem that a large amount of power is required for pressurization. Further, since the intermediate vessel that has become high pressure must be lowered to atmospheric pressure when the gas guide rate is put in again, there has been a problem that the pressure increase is wasted.

Therefore, in order to solve the above problems, gas hydrate gasification apparatuses having a structure in which gas hydrate is introduced from the liquid phase side of the gasification tank (for example, the bottom of the gasification tank) have been used.
JP 2004-75849 A

  However, in a gas hydrate gasifier having a structure in which gas hydrate is introduced from the liquid phase side of the gasification tank (for example, the bottom of the gasification tank), the gas hydrate has a lower density than the liquid. At the same time as the hydrate is introduced, it immediately rises due to buoyancy and stays in a lump on the liquid surface.

  And since the gasification (decomposition) reaction of gas hydrate is an endothermic reaction, if gas hydrate lumps stay on the liquid surface, they take heat away from the surrounding liquid, so the gas hydrate itself freezes. As a result, gasification is hindered, and the gasification efficiency in the gasification tank becomes very poor.

  The present invention has been made in view of such circumstances, and the problem to be solved by the present invention is that when the gas hydrate is supplied from the liquid phase side of the gasification tank (for example, the bottom of the gasification tank), It is an object to provide a gas hydrate gasifier for efficiently gasifying a gas hydrate while suppressing an abrupt rise of the gas hydrate to the liquid surface.

  In order to achieve the above object, a gas hydrate gasification apparatus according to a first aspect of the present invention includes a gasification tank for gasifying a gas hydrate, and a gas hydrate provided at a lower portion of the gasification tank. And a submerged retaining member that is provided in the liquid of the gasification tank and retains a gas hydrate having a particle size of a certain size or more in the liquid.

  According to this aspect, the gas hydrate is supplied from the liquid phase side of the gasification tank (for example, the bottom of the gasification tank) by providing the liquid retaining member that retains the gas hydrate having a certain particle size or more in the liquid. At this time, the sudden rise of the gas hydrate to the liquid surface can be suppressed by the liquid retaining member.

  Because of this action, the gas hydrate having a large particle size reacts with the liquid in the submerged retaining member, reduces the particle size while generating gas, and rises through the submerged retaining member. When reaching the liquid surface, most of it is gasified and does not stay on the liquid surface. Therefore, the efficiency of hydrate gasification can be increased.

  In addition, since the particle size of the gas hydrate passing through the liquid retaining member from the beginning is not so large, it is already gasified when it reaches the liquid surface.

  The gas hydrate gasifier according to a second aspect of the present invention is characterized in that, in the first aspect, the liquid retaining member is constituted by a flow path of a heat medium.

  According to this aspect, even if the gas hydrate stays in the liquid retaining member and the gas hydrate freezes due to the endothermic reaction, the gas hydrate is melted by flowing the heat medium through the liquid retaining member. Then, by reacting with the liquid, gasification can be promoted, and further the retention of the gas hydrate in the submerged retaining member can be eliminated.

  The gas hydrate gasifier according to a third aspect of the present invention is characterized in that, in the first aspect, the submerged member includes a heat generating portion. According to this aspect, the same effect as the second aspect can be obtained.

  A gas hydrate gasification apparatus according to a fourth aspect of the present invention is the gas hydrate gasification apparatus according to any one of the first to third aspects, wherein the gas hydrate is atomized below the submerged member. It is characterized in that a means for reducing the size is provided.

  According to this aspect, since there are many gas hydrates having a particle size that has already been reduced by the action of the atomizing means below the submerged member, the surface area of the gas hydrate is increased and the reactivity with the liquid is also increased. Gasification is promoted and gasification is promoted, and the retention of gas hydrate in the liquid retaining member can be reduced.

  The gas hydrate gasifier according to a fifth aspect of the present invention is the gas hydrate gasifier according to the fourth aspect, wherein the atomizing means is constituted by a wake-up device that causes a swirl flow in the liquid in the gasification tank. It is characterized by.

  In this aspect, the effect similar to the effect of the fourth aspect can be obtained by increasing the reactivity between the gas hydrate and the liquid by the swirling flow and making the gas hydrate smaller.

  The gas hydrate gasifier according to a sixth aspect of the present invention is the gas hydrate gasifier according to the fifth aspect, wherein the wake flow device is configured in multiple stages, and the swirl flow created by the single wake flow device is the wake flow of the other stage. It is comprised so that it may become reverse direction with the swirl flow made with an apparatus.

  According to the main body, by creating a swirl flow with different swirl directions, the gas hydrate comes into contact with the liquid in a state where the gas hydrate is caught between the swirl flows. This is further promoted than in the embodiment.

  The gas hydrate gasifier according to a seventh aspect of the present invention is characterized in that, in the fourth aspect, the atomizing means is constituted by a crushing device for mechanically crushing the gas hydrate. .

  According to this aspect, since the gas hydrate is mechanically crushed by the pulverizer, the particle size of the gas hydrate can be crushed to a considerably small state (fine graining).

  A gas hydrate gasifier according to an eighth aspect of the present invention is characterized in that, in the fifth or sixth aspect, the wake-up device includes a crushing unit that mechanically crushes the gas hydrate. To do.

  Gasification is further promoted by increasing the reactivity of gas hydrate and liquid by swirling flow, and by further refinement of gas hydrate by the pulverization part. Can be significantly increased.

  A gas hydrate gasification apparatus according to a ninth aspect of the present invention is the gas hydrate gasification apparatus according to any one of the first to eighth aspects, wherein a stirring blade is provided above the liquid retaining member. Features.

  According to this aspect, the gas hydrate having a small particle diameter that has passed through the submerged retaining member is further gasified by further increasing the reaction with the liquid while being stirred by the stirring blade, so that the gasification efficiency is good and the liquid Almost no gas hydrate stays on the surface.

  According to the present invention, when the gas hydrate is supplied from the liquid phase side of the gasification tank (for example, the gasification tank bottom), the gas hydrate in the liquid phase is prevented from rapidly rising to the liquid surface, and the efficiency. Gas hydrate can be gasified well.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments.

[First embodiment]
A first embodiment will be described with reference to FIGS. 1 and 2.
In FIG. 1, the gasification tank 1 has a liquid phase L in which water to be reacted with gas hydrate is stored and a gas phase G in which gas generated by the reaction between the gas hydrate and water is stored. Here, the inside of the gasification tank 1 is maintained in a high pressure state (1 to 3 MPa), and the water temperature is set to 5 to 30 ° C.

  In the liquid phase L, a liquid retaining member 3 for retaining the gas hydrate P supplied from the supply unit 2 in the liquid phase L is fixed in the liquid phase L by a locking member 4 and a bolt 5. Yes. The fixing position of the submerged retaining member 3 may be anywhere as long as it is below the liquid level, but is preferably an intermediate position between the liquid level and the bottom of the gasification tank 1. In addition, any fixing member and fixing method for the submerged retaining member 3 can be used as long as they are known.

  FIG. 2 shows the type of the submerged retaining member 3. In (A), a hole is provided in a circular dish-shaped board, and gas hydrate can pass through this hole. (B) is a network having a circular shape and a portion through which gas hydrate can pass.

  Although the circular thing was mentioned as a shape of the submerged member 3, it is not limited to this, The shape of the submerged member 3 is the shape of the gasification tank 1, the shape of gas hydrate, etc. It can be selected as appropriate. The size of the holes and meshes can also be set freely depending on the particle size or shape of the gas hydrate. Moreover, it is also possible to provide a hole for penetrating a drive shaft 20 described later (for example, FIG. 2 (A) a1).

  The material of the liquid retaining member 3 is not particularly limited as long as it can withstand the pressure because the gasification tank 1 is in a high pressure state.

  Since the gas hydrate gasifier according to the present invention has the above-described structure, the gas hydrate P supplied from the supply port 2 does not rise to the liquid level at a stretch, and the submerged retaining member 3 In the portion, it once stays in the liquid (water) and reacts with the liquid (water) to gasify to form a gas hydrate with a small particle size. Then, it passes through the holes of the submerged member 3 and further rises to the liquid level while reacting with the liquid (water). Therefore, when it reaches the liquid level, it is already gasified or is gasified and decomposed. Since the gas hydrate has a very small particle size (in this state, it is immediately gasified), the gas hydrate lump does not stay on the liquid surface. Therefore, the gas hydrate can be efficiently gasified.

  In addition, when supplying the gas hydrate P into the liquid phase L (water), the supply method is not particularly limited. However, when the gas hydrate P is supplied together with the liquid (water), the liquid phase L (water) is supplied. Liquid (water) in) can be used. That is, it is also possible to suck the liquid (water) from the liquid phase L (water) with the pump P, warm it with the heat exchanger, and supply it from the supply unit 2 together with the gas hydrate P.

[Second Embodiment]
A second embodiment will be described with reference to FIGS. 3, 4 and 18.
Note that the description of the same parts as those in the first embodiment will be omitted, and different parts will be described.

  FIG. 18 shows the relationship between the submerged retaining member 3 and the gas hydrate P when the supply of the gas hydrate P is increased in the first embodiment. In the state of FIG. 12, a lump of gas hydrate P remains below the submerged retaining member 3.

  In this state, since the gasification (decomposition) reaction of the gas hydrate P is an endothermic reaction, the mass of the gas hydrate P takes heat from the surrounding liquid (water) below the submerged retaining member 3, and the gas Hydrate P itself freezes. For this reason, the gasification is hindered and the submerged retaining member 3 is clogged to prevent the gas hydrate from rising, and the gasification efficiency in the gasification tank 1 becomes very poor. Have.

  Here, FIG. 3A shows an embodiment of the present invention in which the heat medium flow path 6 is provided in the gasification tank 1 as the liquid retaining member 3. FIG. 4A shows a top view when the tube has a circular network structure (hereinafter “tube”) as an embodiment of the flow path 6 of the heat medium.

  When the heat medium is injected from the outside of the gasification tank 1 from the inlet, the tube moves while warming the tube when passing through the tube, and is discharged from the outlet.

  For this reason, when the tube acting as the submerged member 3 is warmed, the gas hydrate P below the tube is melted, and gasification of the melted gas hydrate begins. Since the particle size is reduced and the gas goes up through the network of the tube, the gasification efficiency of the gas hydrate can be increased.

  About the shape of a tube, it is not limited to the shape of this embodiment, According to the shape of the gasification tank 1, etc., it can select suitably.

  Furthermore, instead of the heat medium flow path 6, the submerged member 3 may be provided with a heat generating portion 6 ′ as shown in FIG. For example, as shown in FIG. 4 (B), if the heating wire is configured in a mesh shape and provided in the gasification tank 1 and the heat source is supplied from the outside of the gasification tank 1, a heat medium is provided in the liquid retaining member 3. The same effect as when using the flow path 6 is obtained.

[Third embodiment]
A third embodiment will be described with reference to FIG.
In addition, description is abbreviate | omitted about the part which overlaps with the 1st and 2nd embodiment, and will suppose that a different part is demonstrated.

  In FIG. 5 (A), the atomizing means 7 for atomizing the gas hydrate is provided below the liquid retaining member 3 (6, 6 '). The granulating means 7 is supported by a drive shaft 20 that passes through the submerged member 3 (6, 6 ′) and is driven using the power of the motor M, and is driven in conjunction with the movement of the drive shaft 20.

  For example, when the drive shaft 20 rotates, the atomizing means 7 also rotates. Then, the gas hydrate P supplied in the liquid phase L is agitated by the rotation of the atomizing means 7, the reactivity with the liquid (water) is increased and gasification is promoted, and the particle size of the gas hydrate P is increased. Can be reduced. Accordingly, the gas hydrate staying below the submerged retaining member 3 (6, 6 ′) is reduced, and the atomized gas hydrate passing through the submerged retaining member 3 (6, 6 ′) Since it reacts with the liquid (water) until it reaches gasification, the gasification efficiency can be further increased.

  The driving mode of the granulating means 7 may be not only rotation but also driving in the vertical direction or driving in the left and right front-rear direction. In order to secure each drive, the drive shaft 20 may be added if necessary.

  FIG. 5B shows an embodiment of the atomization means 7. In this embodiment, eight blades are used, but the number of blades is not particularly limited and can be changed depending on the shape and size of the gas hydrate.

  Further, the shape of the atomizing means 7 is not limited to the blade shape, and may be, for example, a rod shape. As shown in FIG. 5C, a rod-shaped member can be provided directly in a direction perpendicular to the drive shaft.

[Fourth Embodiment]
A fourth embodiment will be described with reference to FIG.
Note that the description of the same parts as those in the first to third embodiments will be omitted, and different parts will be described.

FIG. 6 shows a wake device 7 ′ for generating a swirl flow in the liquid phase L.
In this embodiment, since the swirl flow is generated, the drive shaft 20 performs a rotational motion. As shown in FIG. 6, the wake device 7 ′ is configured with an inclination (angle) with respect to the vertical direction of the drive shaft 20 in order to generate a swirling flow in the liquid.

  In the fourth embodiment, in order to further enhance the effect of the third embodiment, the wake device 7 ′ is configured to have an inclination (angle) with respect to the vertical direction of the drive shaft 20. As a result, the gas hydrate rides on the swirling flow and reacts with the liquid (water) in the liquid, so that gasification and atomization are further promoted than in the third embodiment.

[Fifth Embodiment]
A fifth embodiment will be described with reference to FIG.
It should be noted that the description overlapping with the first to fourth embodiments will be omitted, and different parts will be described.
In the fifth embodiment, the wake device 7 ′ of the fourth embodiment and the wake device 7 ″ in which the inclination (angle) of the drive shaft 20 with respect to the vertical direction is opposite to each other are further provided. It is the aspect which provided.

  By adopting the structure as in the present embodiment, the direction of the swirling flow generated by the current generating devices 7 ′ and 7 ″ is reversed, and the gas hydrate P is caught between the swirling flows. Therefore, the atomization of the gas hydrate P is further promoted than in the third and fourth modes.

  In the present embodiment, the two-stage configuration of the current raising devices 7 ′ and 7 ″ is used, but the effect of the present invention can be obtained even with a structure of two or more stages.

[Sixth Embodiment]
A sixth embodiment will be described with reference to FIGS.
In addition, description is abbreviate | omitted about the part which overlaps with the 1st and 2nd embodiment, and will suppose that a different part is demonstrated.

  In FIG. 8, a crushing device 8 is provided below the submerged retaining member 3 (6, 6 ′) for reducing the gas hydrate. The crushing device 8 is a crushing device that mechanically crushes the gas hydrate, and is supported by a drive shaft 20 that passes through the submerged retaining member 3 (6, 6 ′) and is driven using the power of the motor M. The drive shaft 20 is driven in conjunction with the movement of the drive shaft 20.

  For example, as the drive shaft 20 rotates, the crushing device 8 also rotates. Then, when the crushing device 8 rotates, the gas hydrate P supplied in the liquid phase L is crushed and atomized while being stirred, and the reactivity with the liquid (water) is increased and gasification is promoted.

  In the present embodiment, the particle size of the gas hydrate P can be reduced (reduced) by the effect of rotation and the effect of crushing by a crushing apparatus. Accordingly, the gas hydrate staying below the submerged retaining member 3 (6, 6 ′) is reduced, and the atomized gas hydrate passing through the submerged retaining member 3 (6, 6 ′) Since it reacts with the liquid (water) until it reaches gasification, the gasification efficiency can be further increased.

  The driving mode of the crushing device 8 may be not only the rotation but also the driving in the vertical direction or the driving in the left and right direction. In order to secure each drive, the drive shaft 20 may be added if necessary. It is also possible to provide a plurality of crushing devices 8.

9 to 15 show types of the crushing device 8.
FIG. 9 shows a configuration in which the crushing blades 9 are provided radially on the atomizing means 7 of FIG. 5B of the third embodiment.

  FIG. 10 to FIG. 15 describe types of the crushing device 8, and a plan view is shown in the upper part and a front view is shown in the lower part. The kind of crushing apparatus 8 is not limited to these.

  FIG. 10 is a mode in which a crushing blade b1 is provided on the stirring blade. Although this embodiment has four blades, the effect of crushing can be obtained if two or more blades are used. The crushing blade b1 is on the front surface in the rotation direction, and the crushing performance is improved by having a constant angle α (10 to 60 °).

  Further, the crushing performance is improved by folding the stirring blade at the b2 portion (0 to 80 °) and bending upward at the b3 portion (30 to 90 °). Moreover, about an upper folding part, the stirring effect improves by attaching pitch (beta) (1-30 degrees or -1-30 degrees) to a stirring blade.

  FIG. 11 is a mode in which a part of the stirring blade is folded down at the c3 portion in the mode of FIG. 10, and the crushing performance is improved by providing the stirring blade provided with the crushing blade on the upper and lower objects. It is an improvement.

  12 and 13 are embodiments in which crushing blades d1 and e1 are provided on the front surface of the flat blade in the rotational direction. In FIG. 12, the crushing blade d1 has an arc shape, and in FIG. 13, the crushing blade e1 has a linear shape.

  The crushing blades d1 and e1 have a constant angle α (10 to 60 °), so that the crushing performance is improved. Furthermore, as described in FIG. 13, the stirring effect is improved by having the pitch β (1 to 30 °). Although the number of blades is two in both FIGS. 12 and 13, it is not limited to this. Preferably 2-6 sheets are good.

  FIG. 14 shows an embodiment in which a part of the blade of the embodiment in FIG. 13 is folded upward. In this embodiment, the blade is bent upward at the f1 portion and the f2 portion, and the angle of the bent portion is α (60 °. ), Β (20 °), and γ (10 °), but are not limited to this angle. The same applies to the number of blades.

  FIG. 15 is a combination of the aspects described in FIGS. 11, 12, and 14. In addition, about a combination, it can change suitably with the magnitude | size and shape of a gas hydrate. Moreover, when the crushing apparatus 8 crushes the gas hydrate by rotation, the number of revolutions is about 50 to 1000 rpm although it depends on the size of the gasification tank 1.

[Seventh Embodiment]
A seventh embodiment will be described with reference to FIG.
In addition, description is abbreviate | omitted about the part which overlaps with other embodiment, and suppose that a different part is demonstrated.

  The present embodiment is an embodiment in which a crushing unit 9 for mechanically crushing gas hydrate is provided in the fifth embodiment. Although the crushing part 9 is a crushing blade in this embodiment, it may be other than the blade as long as the gas hydrate can be crushed.

  In this embodiment, in addition to the effects of the fifth embodiment, the gas hydrate is further granulated by the crushing unit 9, so that the efficiency of gasification can be further increased.

[Eighth embodiment]
An eighth embodiment will be described with reference to FIG.
This embodiment is an embodiment in which a stirring blade 10 is provided above the submerged retaining member 3 (6, 6 ′) in the seventh embodiment as described in FIG. By providing the stirring blade 10 above the submerged retaining member 3 (6, 6 ′), the gas hydrate that has passed through the submerged retaining member 3 (6, 6 ′) is further mixed with liquid (water) by stirring. By increasing the reactivity, gasification is promoted and the efficiency of gasification can be increased.
The stirring blade 10 can also be provided in the first to seventh embodiments.

The conceptual diagram in the 1st Embodiment of this invention. The top view of the submerged member in the 1st Embodiment of this invention. The conceptual diagram in the 2nd Embodiment of this invention. The top view of the submerged member in the 2nd Embodiment of this invention. The conceptual diagram in the 3rd Embodiment of this invention. The conceptual diagram in the 4th Embodiment of this invention. The conceptual diagram in the 5th Embodiment of this invention. The conceptual diagram in the 6th Embodiment of this invention. The top view and front view of the kind of crushing apparatus in the 6th Embodiment of this invention. The top view and front view of the kind of crushing apparatus in the 6th Embodiment of this invention. The top view and front view of the kind of crushing apparatus in the 6th Embodiment of this invention. The top view and front view of the kind of crushing apparatus in the 6th Embodiment of this invention. The top view and front view of the kind of crushing apparatus in the 6th Embodiment of this invention. The top view and front view of the kind of crushing apparatus in the 6th Embodiment of this invention. The top view and front view of the kind of crushing apparatus in the 6th Embodiment of this invention. The conceptual diagram in the 7th Embodiment of this invention. The conceptual diagram in the 8th Embodiment of this invention. The conceptual diagram when the gas hydrate is supplied in the first embodiment.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 Gasification tank, 2 Supply part, 3, 6, 6 'Submerged retaining member, 4 latching part, 5 bolt, 7 Granulating means, 7, 7' Emergence device, 8 Crushing device, 9 Crushing blade , 10 Stirring blade, G gas phase, L liquid phase, P pump, H heat source, N heat exchanger

Claims (9)

A gasification tank for gasifying the gas hydrate;
A gas hydrate supply section provided at a lower portion of the gasification tank;
A liquid retaining member that is provided in the liquid of the gasification tank and retains a gas hydrate having a particle size of a certain size or more in the liquid;
A gas hydrate gasification apparatus comprising:   2. The gas hydrate gasification apparatus according to claim 1, wherein the submerged member is constituted by a flow path of a heat medium.   2. The gas hydrate gasifier according to claim 1, wherein the liquid retaining member includes a heat generating portion.   The gas hydrate gasification apparatus according to any one of claims 1 to 3, wherein a granulating means for reducing the gas hydrate is provided below the liquid retaining member. Characterized gas hydrate gasifier.   5. The gas hydrate gasification apparatus according to claim 4, wherein the atomizing means comprises a wake-up device that causes a swirling flow in the liquid in the gasification tank. Device.   6. The gas hydrate gasifier according to claim 5, wherein the wake devices are configured in multiple stages, and the swirl flow created by one wake device is opposite to the swirl flow created by another wake device. A gas hydrate gasifier characterized by comprising:   5. The gas hydrate gasification apparatus according to claim 4, wherein the atomizing means comprises a crushing device for mechanically crushing the gas hydrate.   The gas hydrate gasification apparatus according to claim 5 or 6, wherein the wake unit is provided with a crushing unit for mechanically crushing the gas hydrate. apparatus.   The gas hydrate gasification apparatus according to any one of claims 1 to 8, wherein a stirring blade is provided above the liquid retaining member.

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