JP4753843B2 - Ship - Google Patents

Description

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

Conventionally, diesel engines have been adopted as the main engine of the ship, and heavy oil is used as the 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, the electric drive propulsion mechanism has attracted attention from the viewpoint of the global environment. The electric drive propulsion mechanism obtains propulsive force by turning a motor with electric power generated using a diesel engine as a prime mover and turning a propeller directly connected to the motor. When a ship is electrically propelled, there is generally an energy transmission loss due to a generator, a control device, an electric motor, etc., and the fuel consumption is worse than that of a normal ship. Often. However, by adopting a high-efficiency electric propulsion system, it is possible to minimize this energy transfer loss and to improve fuel efficiency by employing a counter-rotating propeller or the like. Moreover, it has high economic efficiency from the centralized power management by rotating the propeller with a motor, has excellent acceleration / deceleration control response, and can improve the marine vessel maneuvering performance. Furthermore, the mechanical connection of the prime mover, the speed reducer, and the propeller is not required, and the use space can be increased from the flexibility of the inboard layout, the construction cost can be reduced, and the inboard environment can be improved by reducing noise and vibration.

  Further, natural gas energy has attracted attention as a fuel for ships (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 evaporates little by little due to the temperature rise of the tank and a large amount of boil of 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 of gas by burning it with a boiler, etc. There is a problem that increases.

Therefore, recently, NGH has attracted attention as a new natural gas energy. NGH is an 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.
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>

  However, in a conventional ship equipped with a diesel engine fueled with heavy oil, the generator is operated by operating the diesel engine in order to generate electric power. I had to run the diesel engine and turn the generator. As a result, more electricity was generated than necessary when the berth was occupied, and fuel consumption was high. Conventional ships with an electric drive propulsion mechanism also have to operate a generator to supply power during berthing, which consumes less fuel than a diesel direct drive propulsion system, but some fuel Therefore, further improvement is demanded.

  Accordingly, an object of the present invention is to provide a ship that suppresses fuel consumption during berthing and has excellent environmental performance.

  The object of the present invention includes a generator, a motor driven by the electric power generated by the generator, and a propeller driven by the motor, and the propeller is rotated by the motor during navigation. This is achieved by a ship that regenerates electric power by rotating the propeller by tidal current during berthing.

  In the present invention, it is preferable to further include a propulsion direction control mechanism that rotates the direction of the propeller, and to control the direction of the propeller in accordance with the direction of the tidal current.

  In the present invention, it is preferable to monitor the power generation amount due to the regeneration of the power and operate the generator when the power generation level falls below a predetermined power generation level. It is particularly preferable to operate the generator when it is below the power demand in the ship. In the present invention, it is not important to obtain a target amount of power, and it is only necessary to obtain the maximum regenerative power in accordance with the current flow at that time, and to save even a little power by the obtained regenerative power. The purpose of is achieved. In other words, it is sufficient if the regenerative power is sufficient, and the battery may be charged for the remainder, and if it is not sufficient, the generator may be operated and replenished.

  In the present invention, it is preferable that the motor and the propeller constitute a counter-rotating pod propeller. According to this, while being able to implement | achieve a highly efficient electric drive propulsion mechanism, highly efficient electric power regeneration can be implement | achieved.

  The ship according to the present invention preferably further includes an NGH tank storing NGH, and an NGH decomposition apparatus that decomposes NGH supplied from the NGH tank to generate fuel gas, and the generator includes the NGH A gas engine generator that generates electric power using fuel gas generated by a gasifier is preferable.

  Thus, according to the present invention, it is possible to provide a marine vessel that suppresses fuel consumption during anchoring and is excellent in environmental performance.

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

  FIG. 1 is a schematic diagram showing a configuration of a ship according to a preferred embodiment of the present invention.

  As shown in FIG. 1, the ship 10 includes a hull 11, a gas engine generator 12 provided in the hull 11, a battery 13 in which electric power from the gas engine generator 12 is temporarily stored, and a battery 13. A counter-rotating pod propeller 14 that is driven by receiving power supply from, a fuel gas supply unit 15 that supplies fuel gas to the gas engine generator 12, an inboard electrical facility 16 that receives power supply from the battery 13, And a system control unit 17 for controlling these systems.

  The counter rotating pod propeller 14 is a combination of a counter rotating propeller and a pod type electric propulsion mechanism. The contra-rotating propeller includes a front propeller P1 and a rear propeller P2, and is configured such that each propeller is driven by separate motors M1 and M2. Therefore, a strong propulsive force can be obtained even at a low boat speed, and even if one propulsion train fails, operation with the other propulsion train is possible. The propeller rotating motors M1 and M2 are housed in the pod 14a and provided outside the ship. The attachment support portion 14b to the hull 11 is a ladder (rudder), and the pod 14a is configured to rotate 360 ° together with the attachment support portion 14b. This rotation is performed by the motor M3 which constitutes the propulsion direction control mechanism together with the system control unit 17.

  FIG. 2 is a schematic diagram showing the configuration of the fuel gas supply unit 15.

  In the ship 10 of this embodiment, NGH is used as fuel. Therefore, as shown in FIG. 2, the fuel gas supply unit 15 includes an NGH tank 21 that stores spherically solidified NGH (NGH pellets), and an NGH decomposition device 22 that gasifies NGH. ing. As described above, liquefied natural gas (LNG) is well known as natural gas energy. However, LNG is very difficult to handle, such as generation of boil-off gas, and it is necessary to remove boil-off gas. For example, it is more advantageous than LNG in terms of the entire system of manufacturing, transportation, storage, and gasification, and is therefore suitable as a fuel for ships.

  The NGH decomposition apparatus 22 includes an NGH decomposition tank 101 for decomposing the NGH pellets 100 supplied from the NGH tank 21, and a nozzle 102 for spraying NGH decomposition hot water from above the NGH pellets 100 in the NGH decomposition tank 101. It has. The hot water for NGH decomposition is not particularly limited, but water obtained by decomposing NGH (NGH decomposed water) may be heated with a water heater and NGH decomposed water may be circulated for use. Alternatively, NGH-decomposed water whose temperature has been increased by heat exchange with seawater may be used. Alternatively, NGH decomposition water whose temperature has been increased by heat exchange with the gas engine generator or the air conditioning system may be used. By spraying warm water on the NGH pellet 100, the NGH pellet 100 is dissolved, and fuel gas and water are generated. The water obtained at this time is cold water, and the water temperature is −5 to 10 ° C., which is sufficiently lower than room temperature. A net 103 is provided inside the NGH decomposition tank 101, and the NGH pellet 100 and the NGH decomposition water 104 in the NGH decomposition tank 101 are separated vertically by this net 103. The fuel gas generated in the NGH decomposition tank 101 is taken out from the gas discharge port 101 a provided above the NGH decomposition tank 101, and the water 104 generated in the NGH decomposition tank 101 is provided below the NGH decomposition tank 101. It is taken out from the drain port 101b.

  During navigation, the ship 10 obtains a propulsive force by rotating the propellers P1 and P2 with the motors M1 and M2, respectively. At this time, electric power from the gas engine generator 12 is supplied to the motors M1 and M2 via the battery 13, whereby the propellers P1 and P2 rotate. In the present embodiment, by combining the gas engine generator 12 and the battery 13, it is possible to perform a constant operation of the gas engine generator 12 and to store surplus power in the battery 13.

  On the other hand, during berthing, power regeneration is performed in which the propellers P1 and P2 are rotated by the tidal current to generate power by the motors M1 and M2. The electric power generated by the motors M1 and M2 by the rotation of the propellers P1 and P2 is stored in the battery 13. The electric power generated in this way is used for inboard electrical equipment 16 such as an electric lamp, a refrigerator, a television, a radio, a wireless communication device, and an air conditioning system. Normally, the gas engine generator 12 is stopped, but when the power consumption by the onboard electrical equipment 16 exceeds the regenerative power by the propellers P1 and P2, the gas engine generator 12 is operated to generate power, and the battery The power supply to 13 is strengthened.

  In the present embodiment, in order to increase the power generation efficiency due to the tidal current, control is performed to adjust the direction of the propellers P1 and P2 to the direction of the tidal current. Since the counter-rotating pod propeller 14 includes a motor M3 that rotates the directions of the pod 14a and the attachment support portion 14b, the direction of the propellers P1 and P2 is changed by driving the motor M3. In this control, the directions of the propellers P1 and P2 are adjusted while monitoring the power generation amounts by the motors M1 and M2, and the directions of the propellers P1 and P2 are adjusted in the direction in which the power generation amount becomes the largest. Therefore, the rotational force of the propellers P1 and P2 due to the tidal current can always be maximized.

  The amount of power generated by power regeneration and the amount of power demand by the inboard electrical equipment 16 are monitored by the power monitoring unit 18. These monitoring signals are sent to the system control unit 17 and managed by the system control unit 17. When the regenerative power amount is lower than the power demand amount by the inboard electrical equipment 16, the system control unit 17 operates the gas engine generator 12 to supply power to the battery 13.

  As described above, the ship 10 of the present embodiment employs an electric drive propulsion mechanism, uses the propellers P1 and P2 and the motors M1 and M2 constituting the electric drive propulsion mechanism as power generation means, Since the propellers P1 and P2 are rotated to regenerate electric power, fuel consumption during berthing can be reduced. Further, by combining the electric drive propulsion method and the battery, the gas engine generator 12 can be operated at a rating, and noise and vibration at the time of departure or speed change can be suppressed. Further, according to the present embodiment, NGH is adopted as the fuel gas, and the gas engine generator 12 is driven using the fuel gas obtained by decomposing NGH to generate power, so that the fuel gas energy is easily handled. It is possible to realize a ship with excellent environmental performance.

  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, NGH is used as the fuel for the ship, but the present invention is not limited to NGH, and LNG can also be used.

FIG. 1 is a schematic diagram schematically showing the configuration of a ship 10 according to the first embodiment of the present invention. FIG. 2 is a schematic diagram showing the configuration of the fuel gas supply unit 15.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ship 11 Hull 12 Gas engine generator 13 Battery 14 Counter-rotating pod propeller 14a Pod 14b Hull attachment support part 15 Fuel gas supply part 16 Inboard electrical equipment 17 System control part 18 Power monitoring part 21 NGH tank 22 NGH decomposition apparatus 100 NGH Pellet 101a Gas discharge port 101b Drain port 101 NGH decomposition tank 102 Nozzle 103 Net 104 NGH decomposition water M1 Motor M3 Motor P1 Front propeller P2 Rear propeller

Claims (5)

An NGH tank in which NGH as navigation fuel is stored, an NGH decomposition apparatus that decomposes the NGH supplied from the NGH tank to generate fuel gas, a generator that generates electric power using the fuel gas , A motor driven by the electric power generated by the generator, and a propeller driven by the motor,
During navigation, the propeller is rotated by the motor and propelled,
A ship that regenerates electric power by rotating the propeller by tidal current during berthing. Further comprising a propulsion direction control mechanism for rotating the orientation of the propeller with respect to the orientation of the hull, the ship according to claim 1, characterized in that controlling the direction of the propeller in accordance with the orientation of the tide.   The ship according to claim 1 or 2, wherein the power generation amount due to the regeneration of the electric power is monitored, and the generator is operated when it falls below a predetermined power generation level.   The ship according to claim 3, wherein the power demand in the ship is monitored, and the generator is operated when the amount of power generated by the regeneration of the power is less than the power demand in the ship.   The ship according to any one of claims 1 to 4, wherein the motor and the propeller constitute a counter-rotating pod propeller.

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