JP2008126829A - Marine vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a marine vessel in which an interior space can be effectively utilized, and efficient and comfortable sailing is possible. <P>SOLUTION: The marine vessel 10 comprises a hull 11, a cargo space 12 formed at the center of the hull, a cabin 13 provided on a deck in the back of the hull, an NGH container 14 as a fuel tank installed on the back of the cabin 13, a plurality of gas engine power generators 15 driven by fuel gas obtained by the gasification of NGH in the NGH container 14, a motor 16 driven by power from the gas engine power generators 15, and a screw 17 rotated by the motor 16. The gas engine power generators 15 and the motor 16 constitute an electrically driven propulsion mechanism of the marine vessel 10. The motor 16 is provided close to the screw, while the gas engine power generators 15 are separately installed in the vessel. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ship, and particularly to a ship provided with an electric drive propulsion mechanism.

Conventionally, a diesel engine has been adopted as a main engine of a ship, and heavy oil is used as its fuel. However, since air pollutants such as CO ₂ , NOx, and SOx are discharged, it is necessary to suppress it. Control and capital investment (low speed operation, adoption of high efficiency engine and low exhaust gas engine, etc.) are required. In addition, if heavy fuel oil leaks to the sea due to collision or grounding, serious environmental destruction may occur. Therefore, natural gas energy has attracted attention as a fuel from the consideration of the global environment (see Non-Patent Document 1).

  As natural gas energy, liquefied natural gas (LNG) is well known, but since LNG is produced and stored at an extremely low temperature of −162 ° C., it has a problem that it is very difficult to handle. Further, there is a problem that LNG is evaporated little by little due to a rise in the temperature of the tank and a large amount of boil-off gas is generated. In particular, when the ship does not move for 2 to 3 days, the pressure inside the tank becomes very high, so it is necessary to remove the boil-off gas by burning in a boiler, etc., and consuming fuel unnecessarily. As a result, the cost increases.

Therefore, recently, NGH has attracted attention as a new natural gas energy (see Non-Patent Document 1). NGH is a clathrate hydrate in which natural gas molecules (guests) mainly composed of methane, ethane, propane and the like are incorporated into a cluster of water molecules, and is about 170 under an atmospheric pressure environment of −20 ° C. Since it can contain twice as much gas, it has many advantages over LNG in terms of the entire system of manufacturing, transportation, storage, and gasification. NGH is also attracting attention as clean energy because it emits less carbon dioxide and air pollutants than gasoline.
Mitsui Engineering & Shipbuilding Co., Ltd., “Natural Gas Hydrate (NGH)-Mitsui Engineering & Shipbuilding”, [online], [searched on November 21, 2006], Internet <URL: http://www.mes.co.jp/mes_technology /ngh.html>

  In a conventional ship equipped with a large diesel engine, the installation location of the engine is limited to the vicinity of the screw, so the design margin of the ship is small, and the cargo space is compressed as the engine occupies a large space in the ship. There is a problem. In many cases, the engine is located at the lower part of the cabin, so that there is a problem that noise and vibration in the cabin increase.

  On the other hand, although NGH is easier to handle than LNG, it is handled as a spherical solid (pellet) in a low temperature environment of -20 ° C, so NGH should be filled directly into the fuel tank installed in the ship. There is a problem that is difficult. Moreover, after a part of NGH dissolves due to a rise in outside air temperature or a deterioration in transportation conditions, it is solidified again by the cold heat held by the entire NGH, so that it sticks to the piping and supply container, causing trouble in the supply of NGH. There is a fear. Therefore, a method of supplying NGH for each container is conceivable. However, since the united space in the ship is further occupied by the loading of the NGH container, further efficient use of the ship space is desired.

  Accordingly, an object of the present invention is to provide a ship capable of efficient and comfortable navigation while effectively utilizing the space in the ship.

  The above object of the present invention is a ship having an electric drive propulsion mechanism using natural gas as fuel, and generating power using the hull, a fuel tank accommodated in the hull, and the natural gas in the fuel tank as fuel. A plurality of gas generators, a motor driven by the power generated by the gas generator, and a screw driven by the motor, wherein the plurality of gas generators are dispersedly installed in the ship, Achieved by the ship.

  According to the present invention, since the electric drive propulsion mechanism is adopted and the gas generators are dispersedly installed in the empty space in the ship away from the motor, the highly efficient operation can be performed without reducing the cargo space in the ship. Is possible. In particular, when generators that use liquid fuel such as heavy oil are distributed, the risk of troubles such as fuel leaks increases as the number of pipes that send fuel to the generators increases, and the burden of maintenance also increases. However, according to the present embodiment, since NGH is used as the fuel, it is easy to deal with fuel leakage and the maintenance. That is, the synergistic effect by the combination of the fuel gas by NGH and the dispersed arrangement of the generator can be expected.

  In the present invention, the plurality of gas generators may be distributed on the front and rear of the hull, or may be distributed on the starboard and port of the hull. In both cases, the redundant configuration of the generator not only facilitates troubleshooting, but also uses multiple gas generators, so adopt a relatively small gas generator that does not have high power generation capacity. And can be installed easily in a relatively small empty space on the ship.

  In the present invention, it is preferable to operate a plurality of gas generators during a maximum load operation during navigation and to operate at least one gas generator during a partial load operation during navigation or anchorage. In this case, during partial load operation, the gas generator with the lowest noise or vibration may be operated preferentially, and the gas power generation with less operation time is made so that the cumulative operation time from the previous overhaul is uniform. You may operate preferentially from the machine. Furthermore, the gas generator that is the target of failure or maintenance may be skipped from the priority order column. According to this, since the role of the gas engine generator is shared, efficient operation is possible during navigation and at anchoring. Therefore, useless fuel consumption can be eliminated and the cruising distance can be increased.

  In the present invention, the fuel is preferably NGH, and the fuel tank is preferably an NGH container that is detachable from a hull. According to this, transportation of natural gas, loading into a ship, and management during navigation can be facilitated.

  As described above, according to the present invention, it is possible to provide a ship capable of efficient and comfortable navigation while effectively utilizing the space in the ship.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic side view schematically showing the structure of a ship according to a preferred embodiment of the present invention. FIG. 2 is a schematic plan view schematically showing the structure of the ship 10.

  As shown in FIGS. 1 and 2, the ship 10 is installed in the hull 11, the cargo space 12 provided in the center of the hull, the cabin 13 provided on the deck behind the hull, and the cabin 13. NGH container 14 as a fuel tank, a plurality of gas engine generators 15 driven by fuel gas obtained by gasifying NGH in NGH container 14, and the electric power from gas engine generator 15 And a screw 17 that is rotated by the motor 16.

  The gas engine generator 15 and the motor 16 constitute an electric drive propulsion mechanism of the ship 10, and the motor 16 is provided in the immediate vicinity of the screw 17, but the gas engine generator 15 is dispersedly installed in the ship. Yes. In a conventional diesel direct drive propulsion system, a large diesel engine had to be placed in the immediate vicinity of the screw 17, but when the electric drive propulsion mechanism is employed as in this embodiment, the motor 16 Since the gas engine generator 15 can be arranged at a remote location, the gas engine generator 15 can be arranged in a relatively small empty space in the ship away from the motor 16. In addition, as a screw, it is preferable to use what is suitable for an electric drive propulsion mechanism like a counter rotating pod propeller. With the counter-rotating pod propeller, the propulsion efficiency can be significantly increased, and the motor is accommodated in the pod outside the ship, so that the space on the ship can be further increased.

  In the present embodiment, two gas engine generators 15A to 15D are arranged in front of the hull and two in the rear of the hull. In other words, the present embodiment has a configuration in which four gas engine generators are distributed. Two gas engine generators 15 </ b> A and 15 </ b> B in front of the hull are distributed on the starboard and port sides of the hull near the bow away from the motor 16. Further, the gas engine generators 15C and 15D at the rear of the hull are distributed on the starboard side and the port side of the hull near the motor 16, respectively.

  The ship 10 of this embodiment can secure an empty space in the lower part of the cabin by adopting a very small electric drive propulsion mechanism. In the electric drive propulsion mechanism, the gas engine generator 15 and the motor 16 may be connected by the electric wiring 15a, so that the gas engine generators 15A and 15B can be easily provided away from the motor. It is possible to take a wider space below the cabin. The wide empty space thus secured is used as a storage space for the NGH container 14. NGH as fuel for the ship is loaded into the ship together with the NGH container 14.

  The NGH container 14 is provided behind the cabin 13. In the present embodiment, two NGH containers 14 arranged side by side are further stacked in two stages, whereby four NGH containers 14 are loaded. The fuel discharge ports of these NGH containers 14 are connected to the fuel piping in the ship, and are connected to the gas engine generators 15A to 15D via the fuel piping. Two gas engine generators 15 </ b> C and 15 </ b> D in the rear of the hull are installed on both sides of these four NGH containers 14. That is, it is arranged in a relatively narrow space between the NGH container and the hull 11.

  The fuel discharge port of the NGH container 14 has a socket structure. This socket structure needs to be provided at a position where there is no risk of the water obtained with NGH gasification being discharged, and the generated gas is unlikely to remain in the NGH container and can be efficiently ejected. is there. Furthermore, it is preferable that the NGH container is provided with a measuring device for measuring the amount of gas used. Furthermore, this measuring device preferably has a function of constantly measuring the flow rate of the gas flowing through the socket portion and measuring the remaining NGH amount in the container, the container internal pressure, and the tank internal temperature. With these functions, it is possible to detect a gas leak in the NGH container.

  At the time of maximum load operation during navigation, these four gas engine generators 15 are fully operated, and not only power is supplied to the motor 16 but also power is supplied to all electric facilities on the ship. In this case, for example, the gas engine generators 15A and 15B in front of the hull are mainly used for power supply to the electrical equipment in the ship, and the gas engine generators 15C and 15D in the rear of the hull are used for electric drive propulsion. However, when any of the gas engine generators 15A to 15D breaks down, the division of roles may be changed. As described above, efficient and safe navigation can be realized.

  On the other hand, at the time of partial load operation during berthing, for example, only two gas engine generators 15A and 15B in front of the hull are operated, whereby electric power is supplied to all the electric facilities in the ship. Thereby, useless operation of the gas engine generator can be suppressed and fuel consumption can be improved. In addition, during berthing, it is possible to perform maintenance / inspection of the gas engine generators 15C and 15D that are not in operation while supplying power to the electrical equipment on the ship. In addition, you may switch to operation of only the two gas engine generators 15C and 15D of the hull rear as needed.

  In addition, the ship 10 of the present embodiment can efficiently operate the plurality of gas engine generators 15 during navigation, berthing, maintenance, and the like. Specifically, all the gas engine generators 15 are fully operated at the maximum load operation during navigation, and the gas engine generator 15 that gives the lowest noise and vibration during the partial load operation during navigation or anchorage is prioritized. It is possible to carry out a crew member comfort mode operation. In addition, it is possible to perform a device load uniform mode operation in which the gas engine generator 15 with a short operation time is preferentially operated so that the cumulative operation time from the previous overhaul is uniform. Furthermore, a gas engine generator that has failed unexpectedly or a gas engine generator that is subject to regular maintenance may be skipped from the priority order column. In this case, repair and maintenance can be performed while sailing. . In addition, if the buffer is provided in electric power using a storage battery, since it becomes unnecessary to respond | correspond to required electric power instantaneously, the said operation | movement can be made still more flexible.

  As described above, according to the present embodiment, the electric drive propulsion mechanism is adopted, and the gas engine generators 15 are dispersedly installed in the empty space in the ship away from the motor 16, so that the cargo space in the ship High-efficiency operation is possible without reducing In particular, rather than adopting a large gas engine generator that takes charge of all the power supply necessary for the ship, a plurality of gas engine generators 15A to 15D are used, so that the power generation capacity is not so high and relatively small. A simple gas engine generator can be adopted, and it can be easily installed in a relatively narrow space in the ship. As a result, the space on the ship can be used as a cargo space or a storage space for NGH containers, and a large number of NGH containers can be mounted. In addition, since the gas engine generator is assigned a role, efficient operation is possible at the time of navigation and at anchoring. Therefore, useless fuel consumption can be eliminated and the cruising distance can be increased. Furthermore, redundancy of the power generation system can be ensured, and a ship system with excellent safety can be realized.

  Further, according to the present embodiment, since the NGH container is directly used as a fuel tank for the ship, a permanent fuel tank in the ship becomes unnecessary. Accordingly, maintenance of the fuel tank is not necessary, and the construction cost of the ship can be reduced. In addition, a fuel supply line (loading arm) for supplying fuel from the harbor facility to the fuel tank in the ship is not required, and the working time for replenishing fuel can be shortened and the amount of purge gas can be reduced.

  In addition, when the generators are arranged in a distributed manner, the piping for sending fuel to the generators increases, which increases the risk of troubles such as fuel leakage and increases the maintenance burden. Since NGH is used as the fuel, the following effects can be expected.

  First, since gas is used as fuel, detection at the time of fuel leakage is relatively easy. In the discovery of leaks of liquid fuel such as heavy oil, it is necessary to identify the leak location by visual inspection after detecting the leak from an alarm such as a drop in oil pressure.In the case of gas, if a gas detector is installed appropriately, A rough leak location can be automatically identified. Also, by making the gas odorized (natural gas itself is odorless and generally adding an odorous component), as with city gas, it alerts the crew, etc. even if the alarm is not activated. It is also possible to prompt the user.

  In addition, since the fuel is gas, the facility is equivalent to the city gas pipe, and the installation work and material specifications are simple. That is, since the specific gravity is lighter than that of heavy oil fuel, the piping and its fixed structure are fine, the piping connecting portion is simplified, and heating above the flow temperature is not required. In addition, in the case of liquid fuel, it will stick to or drip off the inner surface of the pipe, but in the case of gas, it is sufficient to supply nitrogen and push it out. is there. Furthermore, since the fuel must be sent to the generators arranged at every corner of the hull, in the case of liquid fuel, a pump for increasing the pressure is required just before the rise of the pipe, but in the case of gas fuel The booster pump that should be installed at such a key point becomes unnecessary.

  The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention, and these are also included in the scope of the present invention. Needless to say.

  For example, in the above embodiment, the gas engine generators are provided at the bow and stern respectively, but a plurality of gas engine generators may be provided only at the bow or only at the stern. In particular, when a gas engine generator is installed only at the bow, there will be no gas engine generator at the rear of the hull, that is, around the cabin. The environment can be improved. In any case, a plurality of gas engine generators may be operated during navigation, and at least one gas engine generator may be operated during berthing.

  Moreover, in the said embodiment, although it is set as the structure which piled up the NGH container on the deck of a hull rear part, when there is not enough area for placing an NGH container on a deck, an NGH container is located in the back lower part of a cabin. A space in which a part can enter is provided, and a part of the NGH container may be accommodated in the space. In this case, the reduced cabin space uses the space below the cabin that is vacated by adopting the electric drive propulsion mechanism. Further, the cabin may be divided into a front part and a rear part, and an empty space between the cabin front part and the cabin rear part may be used as an NGH container accommodating part. In this case, the NGH containers are preferably stacked vertically so that the longitudinal direction is substantially perpendicular to the deck surface.

  Moreover, in the said embodiment, although the gas engine generator 15 is each installed in the hull front and back, the empty space of the hull center part is made into the cargo space 12, and the NGH container 14 is arrange | positioned on the deck of the back of a cabin. The present invention is not limited to such a layout. For example, the NGH container 14 is arranged in front of the hull, the gas engine generator 15 is installed in the center and rear of the hull, and the cargo in the empty space below the cabin is placed. It may be a space. Even in such a layout, since the gas engine generators 15 are dispersedly arranged, it is possible to obtain the same operational effects as in the above embodiment.

  Moreover, in the said embodiment, although the NGH container which can be taken out from a hull is used as a fuel tank, this invention is not limited to an NGH container, You may use a normal stationary tank. However, the NGH container is preferable to the stationary tank because it is easy to handle in various situations such as transporting and loading the NGH.

  Moreover, in the said embodiment, although the gas engine generator is used as a gas generator using the natural gas obtained by gasification of NGH, it is also possible to use a gas turbine generator.

  Moreover, in the said embodiment, although NGH is used as a ship's fuel, this invention is not limited to such a case, It is possible to use the above-mentioned LNG and CNG (compressed natural gas). Even when these are used, the effects of the present invention can be achieved. However, it can be said that NGH is preferable as the fuel for the ship according to the present invention in consideration of transportation, loading on the ship, management during navigation, and the like.

FIG. 1 is a schematic side view schematically showing the structure of a ship according to a preferred embodiment of the present invention. FIG. 2 is a schematic side view schematically showing the structure of a ship according to a preferred embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ship 11 Hull 12 Cargo space 13 Cabin 14 Container 15 Gas engine generator 15A Gas engine generator 15B Gas engine generator 15C Gas engine generator 15D Gas engine generator 15a Electric wiring 16 Motor 17 Screw

Claims (9)

A ship provided with an electric drive propulsion mechanism using natural gas as fuel, a hull, a fuel tank accommodated in the hull, and a plurality of gas generators that generate electricity using the natural gas in the fuel tank as fuel And a motor driven by the electric power generated by the gas generator, and a screw driven by the motor,
The ship in which the plurality of gas generators are distributedly installed in the ship.   2. The ship according to claim 1, wherein the plurality of gas generators are distributed and arranged in front of the hull and rear of the hull.   The ship according to claim 1 or 2, wherein the plurality of gas generators are distributed on the starboard side and the port side of the hull.   The plurality of gas generators are operated during maximum load operation during navigation, and at least one gas generator is operated during partial load operation during navigation or berthing. Ship according to the item.   The ship according to claim 4, wherein during the partial load operation, the ship is preferentially operated from a gas generator having the lowest noise or vibration.   6. The ship according to claim 4, wherein, during the partial load operation, the gas generator is preferentially operated from a gas generator having a short operation time so that the accumulated operation time from the previous overhaul is uniform.   The ship according to claim 5 or 6, wherein the gas generator subject to failure or maintenance is skipped from the priority order column.   The ship according to any one of claims 1 to 7, wherein the fuel is NGH.   The ship according to claim 8, wherein the fuel tank is an NGH container that is detachable from a hull.

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