JP2019173376A - Gasification tank and gasification method - Google Patents

Abstract

To provide a gasification tank and a gasification method capable of efficiently gasifying a gas-hydrate.SOLUTION: A gasification tank is provided with a breaking nozzle 10 and a thawing nozzle 11 on an upper inside of a gasification tank 1 to which gas-hydrate m in a lump is supplied together with water on a water bottom 3. A gasification method comprises: a step separating gas-hydrate m from each other by injecting water from the breaking nozzle 10 to the gas-hydrate m in a lump floating on water in the gasification tank 1; and a step thawing the gas-hydrate m by spraying water from the thawing nozzle 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a gasification tank and a gasification method for recovering and gasifying a massive gas hydrate at the bottom of the water together with water at the bottom of the water, and more specifically, a gasification tank and a gas capable of efficiently gasifying the gas hydrate. It relates to the conversion method.

  Various gasification methods have been proposed in which methane gas hydrate present at the bottom of the sea or lake (hereinafter sometimes referred to as water bottom) is recovered and melted (see, for example, Patent Document 1).

  Patent Document 1 proposes a gasification method in which massive gas hydrate and surface layer water are supplied to a separator tank, and the gas hydrate is melted by the heat of surface layer water to extract gas.

  Since melting of gas hydrate is an endothermic reaction, the molten water of gas hydrate and surrounding seawater may be frozen. Along with this, the massive gas hydrates sometimes adhered to each other and grew into a relatively large plate shape. Compared with a plurality of massive gas hydrates, the plate-shaped gas hydrate has a significantly smaller contact area with surface water. Heat exchange between the gas hydrate and the surface water could not be performed efficiently. Therefore, the gas hydrate could not be efficiently gasified.

  The plate-like gas hydrate stays in the separator tank and grows further. In such a case, it is necessary to suppress or stop the inflow of gas hydrate that is excavated at the bottom of the water and collected in a separate tank. Therefore, there has been a problem that the gas production efficiency is remarkably lowered.

Japanese Unexamined Patent Publication No. 2015-031097

  This invention is made | formed in view of said problem, The objective is to provide the gasification tank and gasification method which can gasify gas hydrate efficiently.

  A gasification tank for achieving the above object is a gasification tank that collects and gasifies a massive gas hydrate collected from the bottom of the water together with water at the bottom of the water. A crushing nozzle for separating water from the bulk gas hydrate by spraying water from above the bulk gas hydrate, and spraying water from above the bulk gas hydrate to form the bulk gas hydrate. And a melting nozzle for melting.

A gasification method for achieving the above object is a gasification method in which a massive gas hydrate recovered from the bottom of the water together with the water at the bottom is recovered and gasified in a gasification tank. A crushing step of separating the bulk gas hydrate by spraying water from above the bulk gas hydrate floating on the water surface, and spraying water from above the bulk gas hydrate to spray the gas And a melting step for melting the hydrate.

  According to the gasification tank and the gasification method of the present invention, it is possible to prevent the gas hydrates in a lump form from adhering to each other and growing into a large lump by water sprayed from the crushing nozzle. Since it becomes easy to maintain a state where a plurality of massive gas hydrates are separated from each other, it is advantageous to efficiently gasify the gas hydrate.

It is explanatory drawing which illustrates a gas hydrate collection | recovery apparatus provided with the gasification tank of this invention. It is explanatory drawing which illustrates the gasification tank of this invention. It is explanatory drawing which illustrates the gasification tank of FIG. 2 by planar view. FIG. 3 is an explanatory view illustrating the nozzle unit of FIG. 2 in perspective. It is explanatory drawing which illustrates the modification of the gasification tank of FIG. It is explanatory drawing which illustrates the modification of the gasification tank of FIG. It is explanatory drawing which illustrates the state of the crushing process in the gasification tank of FIG. It is explanatory drawing which illustrates the modification of the gasification tank of FIG. It is explanatory drawing which illustrates the modification of the gasification tank of FIG.

  Hereinafter, a gasification tank and a gasification method of the present invention will be described based on the embodiments shown in the drawings.

  As illustrated in FIG. 1, the gasification tank 1 of the present invention is an apparatus incorporated in a gas hydrate recovery apparatus 2. The gas hydrate recovery device 2 excavates a gas hydrate m such as methane existing in the bottom 3 of the sea or lake, and collects a massive gas hydrate m, and the excavation mechanism 4 collects the gas hydrate m. And a riser pipe 5 that conveys the gas hydrate m that has been conveyed upward from the vicinity of the water bottom 3.

  The gas hydrate recovery device 2 includes a structure 6 such as a ship or a floating body arranged near the water surface. The gasification tank 1 is arranged in this structure 6. The upper end of the riser pipe 5 is connected to the gasification tank 1 directly or indirectly. The structure 6 in which the gasification tank 1 is installed is not limited to a ship or the like arranged near the water surface, but may be composed of a land structure or a floating body arranged in water.

  The gas hydrate recovery device 2 includes a gas supply line 7 having one end connected to the gasification tank 1. The other end of the gas supply line 7 is connected to a storage tank that stores the gas g, a device that transports the gas g, and a pipeline that transports the gas g to a consumption place.

  Further, the gas hydrate recovery device 2 includes a discharge pipe 8 whose one end is directly or indirectly connected to the gasification tank 1. The discharge pipe 8 has a structure for discharging water and earth and sand in the gasification tank 1 to the vicinity of the bottom 3.

  When the gas g is produced by the gas hydrate recovery device 2, the bottom 3 is first excavated by the excavating mechanism 4 constituted by a drill bit, an underwater heavy machine, etc., and the massive gas hydrate m is collected. Since the gas hydrate m contains gas resources such as methane gas and has a relatively small specific gravity, the gas hydrate m moves upward in the riser pipe 5 by buoyancy.

Since the water pressure becomes lower and the temperature becomes higher as it approaches the water surface, the gas hydrate m rising in the riser pipe 5 may melt and generate gas g bubbles. Since the amount of bubbles increases as it approaches the upper end of the riser tube 5, the density of the fluid in the riser tube 5 decreases as it approaches the upper end.

  Since the specific gravity difference between the lower end and the upper end of the riser pipe 5 becomes large, an upward flow is generated in the riser pipe 5 due to this specific gravity difference. The same effect as a so-called air lift pump occurs. By this upward flow, water and earth and sand (hereinafter sometimes referred to as slurry) in the vicinity of the bottom 3 together with the massive gas hydrate m are sucked up by the riser pipe 5 and collected in the gasification tank 1.

  In the gasification tank 1, the massive gas hydrate m is melted and gasified. The gas g inside the gasification tank 1 is taken out from the gasification tank 1 via the gas supply line 7.

  Water and earth and sand inside the gasification tank 1 are discharged to the outside via the discharge pipe 8. In this specification, the earth and sand refers to solids such as gravel and sand mud collected from the bottom 3 together with the gas hydrate m.

  By repeating the above, the gas hydrate recovery device 2 produces gas g. The configuration of the gas hydrate recovery device 2 is not limited to the above. It suffices to have at least a configuration in which the massive gas hydrate m is collected from the bottom 3 and supplied to the gasification tank 1.

  As illustrated in FIGS. 2 and 3, the gasification tank 1 is composed of an ellipsoidal tank. The shape of the gasification tank 1 is not limited to this, and may be a rectangular parallelepiped or a sphere. The gasification tank 1 can be configured, for example, so that the length in the longitudinal direction x is about 10 to 30 m, the length in the short direction y is about 5 to 15 m, and the length in the vertical direction z is about 5 to 15 m. The size of the tank is not limited to the above, and can be appropriately changed according to the scale of the gas hydrate recovery device 2.

  The gasification tank 1 includes a supply port 9 for introducing the slurry sent from the riser pipe 5 into the gasification tank 1, a crushing nozzle 10 and a melting nozzle 11 disposed above the gasification tank 1. It has.

  In the embodiment illustrated in FIG. 2, the supply port 9 is disposed at a position higher than the water level in the gasification tank 1, but the present invention is not limited to this configuration. The supply port 9 may be arranged at a position lower than the water surface. In the embodiment illustrated in FIG. 2, the crushing nozzle 10 and the melting nozzle 11 are arranged on the upper surface inside the gasification tank 1, but the present invention is not limited to this configuration. The crushing nozzle 10 and the melting nozzle need only be arranged at a position higher than the water level in the gasification tank 1.

  In this specification, the crushing nozzle 10 refers to a water flow that gives impact to the massive gas hydrate m floating in the water in the gasification tank 1 and prevents the massive gas hydrate m from sticking together. It is a nozzle that generates Alternatively, the crushing nozzle 10 is a nozzle that generates a water flow that separates the massive gas hydrates m fixed to each other.

  The crushing nozzle 10 has a configuration capable of injecting water at a flow rate necessary for separating the massive gas hydrates m. In this specification, the flow rate required to separate the massive gas hydrates m means, for example, a flow rate of 4 m / sec or more when colliding with the gas hydrate m. When the crushing nozzle 10 is installed, for example, at a position 2 m above the water surface in the gasification tank 1, the water sprayed at the discharge port of the crushing nozzle 10 is set to about 2 m / sec.

  The crushing nozzle 10 only needs to have at least one of the function of suppressing the sticking of the massive gas hydrates m or separating the already stuck ones. Therefore, the temperature of the water sprayed from the crushing nozzle 10 may be any temperature, for example, a relatively low temperature such as 5 ° C. or less.

  The crushing nozzle 10 is a nozzle that generates a straight flow with a spray angle of, for example, 0 degrees. The spray angle refers to the range in which the fluid ejected from the nozzle spreads.

  The spray angle of the crushing nozzle 10 is not limited to the above, and it is sufficient that an impact can be given to the massive gas hydrate m floating in the water. For example, it can be configured by a nozzle having a spray angle of 150 degrees and a spray pattern having a flat shape (substantially rectangular shape). A spray pattern means the shape of the cross section orthogonal to the injection direction of a fluid.

  In the present specification, the melting nozzle 11 is a nozzle that generates a water flow that melts the massive gas hydrate m by supplying heat to the massive gas hydrate m floating in the water in the gasification tank 1. is there. Therefore, the temperature of the water sprayed from the melting nozzle 11 is preferably as high as possible, and can be set to, for example, about 5 to 40 ° C. The temperature of the water sprayed from the melting nozzle 11 is not limited to the above, and any temperature higher than 0 ° C. may be used as long as the massive gas hydrate can be melted.

  The melting nozzle 11 has a configuration capable of spraying water at a flow rate necessary for melting the massive gas hydrate m. In the present specification, the flow rate necessary for melting the massive gas hydrate m means a flow rate of, for example, 0.2 m / sec or more when colliding with the gas hydrate m. This flow velocity may be 2 m / sec, for example. The faster the flow rate of water sprayed from the melting nozzle 11, the greater the pressure when colliding with the gas hydrate m. Since the pressure on the surface of the gas hydrate m is increased, the temperature of the gas hydrate m is likely to rise, and as a result, the gas hydrate m is easily melted.

  The melting nozzle 11 only needs to have a function of applying heat to the massive gas hydrate floating in water. Therefore, any spray angle and spray pattern of the melting nozzle 11 may be used. In order to efficiently supply heat to the massive gas hydrate distributed in a relatively wide range in the gasification tank 1, it is desirable that the melting nozzle 11 has a configuration capable of spraying water over a wide range. For example, the melting nozzle 11 can be configured by a nozzle having a spray angle of 15 to 170 degrees and a spray pattern having a full cone shape (circular shape).

  It is desirable that the particle diameter of water sprayed from the melting nozzle 11 is, for example, 300 μm or less. This is because the water sprayed from the melting nozzle 11 can be prevented from exchanging heat with the surrounding water before transferring the heat to the massive gas hydrate m.

  The range of water sprayed by the crushing nozzle 10 is configured to be smaller than the range of water sprayed by the melting nozzle 11. In the present specification, the range of water refers to a range of spread in the horizontal direction when water discharged from the crushing nozzle 10 or the melting nozzle 11 reaches the water level in the gasification tank 1.

  Further, the impact force per unit area when reaching the water surface in the gasification tank 1 is larger for the water discharged from the crushing nozzle 10 than for the water discharged from the melting nozzle 11.

As illustrated in FIG. 4, a nozzle unit 12 including one crushing nozzle 10 and a plurality of melting nozzles 11 arranged around the crushing nozzle 10 is configured, and the nozzle unit 12 is gasified. You may make it the structure arrange | positioned on the upper surface inside the tank 1. FIG. In this embodiment, six melting nozzles 11 are arranged at equal intervals around one crushing nozzle 10.

  As illustrated in FIG. 2, the gasification tank 1 includes a water intake 13 for taking water inside, a pipe 14 that communicates the water intake 13 and the nozzle unit 12, and a pump that is installed in the middle of the pipe 14. 15.

  As illustrated in FIGS. 2 and 3, slurry is supplied to the gasification tank 1 from a supply port 9. The slurry contains water at the bottom 3, a massive gas hydrate m having a diameter of, for example, about 20 to 30 mm, and earth and sand having a diameter of, for example, about 2 μm to 30 mm. The massive gas hydrate m has a specific gravity smaller than that of water, and thus floats on the water surface. Since earth and sand have a higher specific gravity than water, they will sink to the bottom of the gasification tank 1.

  The water collected at the water intake 13 is pressurized by the pump 15 and sent to the nozzle unit 12. A part of the water sent to the nozzle unit 12 is jetted from the crushing nozzle 10 and the rest is sprayed from the melting nozzle 11. Due to the impact of water sprayed from the crushing nozzle 10, the massive gas hydrates m floating on the water surface and fixed to each other are separated (crushing step). By the water sprayed from the crushing nozzle 10, the massive gas hydrates m floating on the water surface and approaching each other are dispersed (crushing step). Moreover, since the floating water of the massive gas hydrate m is agitated by the water sprayed from the crushing nozzle 10, the massive gas hydrates m can be prevented from sticking to each other.

  On the other hand, water sprayed from the melting nozzle 11 adheres to the massive gas hydrate m floating on the water surface, and heat is supplied (melting step). As the gas hydrate m is melted, gas g is generated.

  The gas g is sent from the gasification tank 1 to the gas supply line 7 and collected. Water and earth and sand are sent from the gasification tank 1 to the discharge pipe 8 and returned to the bottom 3.

  As illustrated in FIG. 3, in this embodiment, four nozzle units 12 are arranged inside the gasification tank 1. In FIG. 3, the wall surface of the gasification tank 1 is indicated by a broken line for the sake of explanation. The number of nozzle units 12 installed in the gasification tank 1 is not limited to this, and can be appropriately changed according to the size of the gasification tank 1 and the amount of gas hydrate m to be supplied.

  The gasification tank 1 of the present invention can suppress the growth of the gas hydrate m in the form of a plate due to the configuration provided with the crushing nozzle 10 and sticking together. By dispersing the massive gas hydrate m, the gas hydrate m can maintain a large contact area with surrounding water or water sprayed from the melting nozzle 11. It is advantageous for efficiently gasifying the gas hydrate m.

  Moreover, the gasification tank 1 becomes easy to supply heat to the block-shaped gas hydrate m by the structure provided with the nozzle 11 for melting which sprays water in a wide range. It is advantageous for efficiently gasifying the gas hydrate m.

With the configuration in which the water collected at the water intake 13 is supplied to the crushing nozzle 10 and the melting nozzle 11, the gasification tank 1 suppresses the gas hydrates m from sticking to each other without changing the amount of water in the tank. It can be efficiently melted. The total amount of fluid in the gasification tank 1 can be managed by controlling the flow rate of the slurry supplied from the riser pipe 5 and the flow rate of water discharged from the discharge pipe 8. Therefore, production management of gas g in the gasification tank 1 can be performed relatively easily. For example, even if the flow rate of the slurry supplied from the riser pipe 5 is higher than expected and the total amount of fluid in the gasification tank 1 is excessively increased, the crushing nozzle 10 is not affected by this. The water can be jetted to separate the gas hydrates m to promote melting.

  The configuration of the gasification tank 1 is not limited to the above, and surface water having a relatively high temperature may be supplied from the crushing nozzle 10 or the melting nozzle 11.

  The jet of water from the crushing nozzle 10 can be configured to always be performed while the gas hydrate recovery device 2 is in operation. In this case, the gas hydrates m can be prevented from sticking to each other. Since the water in the gasification tank 1 is constantly stirred by the jet of water from the crushing nozzle 10, it is advantageous for promoting the melting of the gas hydrate m.

  The jet of water from the crushing nozzle 10 can be intermittently performed every predetermined time. For example, a predetermined amount of water may be ejected from the crushing nozzle 10 every 5 minutes. In this case, the water injection amount per time can be determined as appropriate.

  The pump 15 can be appropriately stopped by a configuration in which water is jetted intermittently from the crushing nozzle 10. This is advantageous for improving the energy efficiency of the entire gasification tank 1.

  It is good also as a structure which heats the water supplied to the nozzle 11 for a fusion | melting with a heat exchanger, a heater, etc. Since the temperature of the water sprayed from the melting nozzle 11 is increased, it is advantageous for promoting the melting of the gas hydrate m. For example, in the embodiment illustrated in FIG. 2, a heater may be installed on the upstream side of the nozzle unit 12. Since the temperature of the water sprayed from the crushing nozzle 10 also becomes high, the temperature of the water in the gasification tank 1 can be raised. It is advantageous for promoting the melting of the gas hydrate m.

  In the present invention, the nozzle unit 12 is not an essential component. The crushing nozzle 10 and the melting nozzle 11 may be arranged in the gasification tank 1 independently without being unitized.

  As illustrated in FIG. 5, the water intake 13 can be arranged at the bottom of the gasification tank 1. In this embodiment, the water intake 13 and the crushing nozzle 10 are communicated with each other by a pipe 14. Since the water intake 13 is installed at the bottom of the gasification tank 1, the earth and sand can be collected together with the water in the gasification tank 1 and sent to the crushing nozzle 10.

  The bottom surface of the gasification tank 1 may be inclined downward from the supply port 9 side toward the discharge pipe 8 side. It is advantageous to make it easy to collect earth and sand at the water intake 13 installed in the vicinity of the discharge pipe 8. A pump 15 is installed in the middle of the pipe 14.

  Since crushing nozzle 10 injects solid earth and sand together with water, it is possible to increase the impact force exerted on massive gas hydrate m floating in water. Therefore, it becomes easy to separate the gas hydrates m adhering to each other. Moreover, since the water in the gasification tank 1 is agitated by the injection of earth and sand, it is advantageous to further suppress the sticking of the massive gas hydrates m.

  In the embodiment illustrated in FIG. 2, fine earth and sand having a particle diameter of, for example, about 2 μm to 1 mm may be collected from the water intake 13 and sent to the nozzle unit 12 together with water. At this time, solid earth and sand are sprayed together with water from the crushing nozzle 10 and the melting nozzle 11.

  It is desirable to install a filter 16 that allows only soil and sand of a size that can be ejected from the crushing nozzle 10 to pass through the water inlet 13. It can suppress that the nozzle 10 for crushing obstruct | occludes with earth and sand.

  Although the pipe 14 may be connected to the melting nozzle 11 together with the crushing nozzle 10, it is desirable to connect the pipe 17 configured in a system different from the pipe 14 to the melting nozzle 11. According to this configuration, since earth and sand are not supplied to the melting nozzle 11, problems such as blockage due to earth and sand do not occur even if the opening of the melting nozzle 11 is formed to be relatively small.

  With the configuration of the two flow paths of the pipe 14 and the pipe 17, the start and stop of the water supplied to the crushing nozzle 10 and the melting nozzle 11, the water temperature, the flow rate, and the like are independent of each other. Can be controlled. It is advantageous for efficiently gasifying the gas hydrate m.

  The pipe 17 connected to the melting nozzle 11 may be configured to be supplied with surface water having a relatively high temperature, for example.

  Alternatively, a separate water intake may be installed at a position above the bottom of the gasification tank 1 so that water that does not contain earth and sand is supplied to the pipe 17. At this time, a heater may be installed in the middle portion of the pipe 17 to heat the water passing therethrough and then supply it to the melting nozzle 11. It is good also as a structure which installs a heat exchanger instead of a heater and heats the water which passes with the heat of surface water.

  In this case, since the water collected from the bottom 3 and supplied to the gasification tank 1 is not mixed with the surface water, the movement of microorganisms and the like between the bottom 3 and the surface can be suppressed.

  As illustrated in FIG. 6, the gasification tank 1 includes a measurement sensor 18 that measures the presence or absence of sticking between the massive gas hydrates m, and a control mechanism 19 that is connected to the measurement sensor 18 by a signal line. It may be. In FIG. 6, the signal lines are indicated by alternate long and short dash lines for explanation. In this embodiment, a valve 20 is arranged on the upstream side of the crushing nozzle 10. Each valve 20 is connected to the control mechanism 19 by a signal line. The control mechanism 19 controls the start and stop of water injection from the crushing nozzle 10 by controlling the opening and closing of the valve 20.

  The measurement sensor 18 can be composed of, for example, a camera and a device that processes an image acquired by the camera. In this case, the state of the water surface in the gasification tank 1 is first photographed with a camera installed inside the gasification tank 1. When there is a portion where a plurality of massive gas hydrates m are gathered, the measurement sensor 18 determines that the gas hydrates m are fixed, and outputs the fact to the control mechanism 19. The control mechanism 19 opens the valve 20 according to the output from the measurement sensor 18. Thereby, the injection of water from the crushing nozzle 10 is started, and the massive gas hydrate m is separated and dispersed.

  As illustrated in FIG. 7, when the portion where the massive gas hydrates m are gathered by the jet of water from the crushing nozzle 10, the measurement sensor 18 determines that the gas hydrates m are not fixed to each other. Then, this is output to the control mechanism 19. The control mechanism 19 closes the valve 20 according to the output from the measurement sensor 18. Thereby, the injection of water from the crushing nozzle 10 is stopped.

  The configuration of the measurement sensor 18 is not limited to the above. For example, a laser sensor that determines the presence or absence of ice from the difference in refractive index between water and ice, or an icing detection sensor that determines the presence or absence of ice from the difference in vibration frequency of the vibrator can be used.

  When the measurement sensor 18 is configured by a laser sensor, a laser sensor is disposed above the inside of the gasification tank 1 and the laser is scanned along, for example, the longitudinal direction x or the lateral direction y. If there is water between the massive gas hydrates m, this can be detected from the difference in refractive index. If the gas hydrate m is frozen, it can be detected as a continuous plate of ice.

  In the case where the measurement sensor 18 is composed of an icing detection sensor, a plurality of icing detection sensors are installed at positions near the water surface inside the gasification tank 1. When the gas hydrate m adheres to the vibrator of the icing detection sensor and freezes, the mass of the vibrator increases and the frequency of vibration changes. When the gas hydrate m is frozen and attached to the icing detection sensor, there is a high possibility that the surrounding gas hydrates m are similarly fixed to each other. Whether or not plate-like ice is generated can be detected from the difference in vibration frequency of the vibrator.

  The control method by the control mechanism 19 is not limited to the above. When the gas hydrates m are stuck to each other, the control mechanism 19 may perform control to open the valve 20 for a predetermined time such as 10 seconds and close the valve 20 after the predetermined time elapses.

  Regardless of the presence or absence of water injection from the crushing nozzle 10, the water spray from the melting nozzle 11 can be continuously performed. It is good also as a structure which stops spraying of the water from the nozzle 11 for melting, while the water is being injected from the nozzle 10 for crushing. By stopping the spraying of water from the melting nozzle 11, it is possible to improve accuracy when the measurement sensor 18 detects whether or not the gas hydrates m are fixed.

  The control mechanism 19 may control the pump 15 to control the start and stop of water injection from the crushing nozzle 10. In this case, the gasification tank 1 may not include the valve 20.

  According to the configuration including the measurement sensor 18 and the control mechanism 19, water can be jetted from the crushing nozzle 10 only when necessary. Therefore, it is advantageous to improve the energy efficiency of the entire gasification tank 1 while avoiding the problem that the gas hydrates m adhere to each other and grow into a plate shape.

  As illustrated in FIG. 8, the gasification tank 1 may be configured to include a determination mechanism 21 that determines a place where the massive gas hydrates m are stuck to each other. The determination mechanism 21 is connected between the measurement sensor 18 and the control mechanism 19 with a signal line. In FIG. 8, the signal lines are indicated by alternate long and short dash lines for explanation. In FIG. 8, the melting nozzle 11 is omitted. The determination mechanism 21 has a function of identifying the location where the gas hydrates m are stuck to each other based on the output from the measurement sensor 18.

  Based on the location information acquired from the determination mechanism 21, the control mechanism 19 injects water from the crushing nozzle 10 to the location and separates the gas hydrates m from each other.

  In this embodiment, the control mechanism 19 controls the opening and closing of the valve 20 so that water is jetted only from the corresponding crushing nozzles 10 among the plurality of crushing nozzles 10.

According to this configuration, even if there is a place where the flow of the slurry is slow in the gasification tank 1 and the gas hydrates m are likely to stick together, the gas hydrate m can be intensively separated at this place. it can. Since water can be sprayed from the crushing nozzle 10 only in a predetermined place, it is advantageous for improving the energy efficiency of the entire gasification tank 1. In particular, it is advantageous when the gasification tank 1 is large and a large number of crushing nozzles 10 such as 20 or 100 are installed.

  In this embodiment, the crushing nozzle 10 may be installed in the gasification tank 1 via a tilting mechanism. By tilting the crushing nozzle 10 with the tilting mechanism, it becomes possible to eject water toward a plurality of locations with a relatively small number of crushing nozzles 10. While suppressing the number of crushing nozzles 10 installed, water can be sprayed to a place where the gas hydrates m are stuck to each other.

  The gasification tank 1 may have a control mechanism 19 without the measurement sensor 18. At this time, the control mechanism 19 has a configuration that independently controls the start and stop of water injection from the crushing nozzle 10 without depending on the output from the measurement sensor 18. The control mechanism 19 may have a configuration that switches between a continuous operation state in which water is continuously injected and an intermittent operation state in which water is intermittently injected. The switching between the continuous operation state and the intermittent operation state can be performed by, for example, a switch operation by an operator. Further, the control mechanism 19 may include a configuration in which it is possible to set a time during which water is continuously injected and a time during which water injection is stopped during the intermittent operation state.

  Similarly to the above, the control mechanism 19 may be configured to control the start and stop of water injection from the melting nozzle 11.

  As illustrated in FIG. 9, the crushing nozzles 10 and the melting nozzles 11 may be arranged uniformly over the entire gasification tank 1 in plan view. In this specification, the whole gasification tank 1 means the whole area P formed on a flat surface of the ceiling of the gasification tank 1 formed of an approximately ellipsoid. In FIG. 9, the wall surface of the gasification tank 1 is indicated by a broken line and the range of the region P is indicated by a one-dot chain line for explanation. In FIG. 9, some members such as the gas supply line 7 and the pipe 17 are omitted for explanation.

  In the present specification, the uniform arrangement means that a plurality of crushing nozzles 10 are arranged in a state where the distances between the crushing nozzles 10 are maintained at equal intervals. In addition, a plurality of melting nozzles 11 are arranged on the circumference centering on the crushing nozzle 10, and the plurality of melting nozzles 11 are arranged in a state where the intervals between adjacent melting nozzles 11 are maintained at equal intervals. Means that.

DESCRIPTION OF SYMBOLS 1 Gasification tank 2 Gas hydrate collection | recovery apparatus 3 Water bottom 4 Excavation mechanism 5 Riser pipe 6 Structure 7 Gas supply line 8 Discharge pipe 9 Supply port 10 Crushing nozzle 11 Melting nozzle 12 Nozzle unit 13 Intake port 14 Pipe 15 Pump 16 Filter 17 Pipe 18 Measurement sensor 19 Control mechanism 20 Valve 21 Determination mechanism m Gas hydrate g Gas P Region x Longitudinal direction y Short direction z Vertical direction

Claims (12)

In the gasification tank that collects and gasifies the massive gas hydrate collected from the bottom of the water together with the bottom water,
A crushing nozzle that separates the massive gas hydrates by jetting water from above the massive gas hydrates collected with water and floating on the water surface;
A gasification tank comprising: a melting nozzle for spraying water from above the massive gas hydrate to melt the massive gas hydrate.   The gasification tank according to claim 1, wherein the crushing nozzle has a spray angle smaller than a spray angle of the melting nozzle.   The gasification tank according to claim 1, further comprising a water intake port disposed at a bottom of the gasification tank, and a pipe communicating the water intake port and the crushing nozzle.   The gasification tank according to claim 3, wherein the intake port includes a configuration in which earth and sand collected together with water in the bottom of the water is supplied to the pipe together with water.   The gasification tank in any one of Claims 1-4 provided with the control mechanism which controls the start and stop of the injection of water about at least one of the nozzle for crushing or the nozzle for melting.   The gasification tank according to claim 5, wherein the control mechanism is configured to switch between a continuous operation state in which water is continuously injected and an intermittent operation state in which water is intermittently injected.   The gasification tank according to claim 6, wherein the control mechanism has a configuration in which a time during which water is continuously injected and a time during which the water injection is stopped can be set in the intermittent operation state. A measuring sensor for measuring the presence or absence of sticking between the massive gas hydrates,
The gasification tank according to claim 5, wherein the control mechanism controls the start and stop of water injection from the crushing nozzle according to the output from the measurement sensor. A determination mechanism for determining a location where the sticking of the massive gas hydrates occurs in the gasification tank based on an output from the measurement sensor;
The gasification tank according to claim 8, wherein the control mechanism is configured to perform control for injecting water from the crushing nozzle to the place obtained from the determination mechanism. In the gasification method of collecting and gasifying the massive gas hydrate recovered from the bottom of the water together with the water in the bottom of the water into a gasification tank,
A crushing step of separating the massive gas hydrates by injecting water from above the massive gas hydrate recovered together with the water in the bottom and floating on the water surface;
A gasification method comprising: a melting step of spraying water from above the massive gas hydrate to melt the gas hydrate. The crushing nozzle has a configuration capable of injecting water at a flow rate necessary to separate the massive gas hydrates,
The gasification tank according to claim 1 or 2, wherein the melting nozzle has a configuration capable of spraying water at a flow rate necessary for melting the massive gas hydrate.   3. The gasification tank according to claim 1, wherein the melting nozzle and the crushing nozzle are equally arranged over the entire gasification tank in a plan view.

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