JP4253636B2 - Marine vessel propulsion structure and operation method thereof - Google Patents

Description

  The present invention relates to a marine vessel propulsion system according to the preamble of claim 1. The invention also relates to a method for operating a marine vessel propulsion system according to the preamble of claim 8.

  The overall goals of marine vessel propulsion system design are efficiency, reliability and durability, and good low-speed maneuvering performance, to name a few. The emphasis of features depends on the application in question.

  There is a need to provide a propulsion system that is efficient at cruising speeds, for example, speeds exceeding 25 knots, and at the same time provides excellent harbor maneuvering performance, for example in ships called ROPAX ships (RO-RO passenger ships).

  In place of conventional mechanical shaft propulsion, the use of azimuthing propulsion drives, called pod drives, has been proposed. Reference is made to European Patent Publication No. 590867, which shows a propulsion structure comprising a rotatable drive unit with an electric motor connected to a propeller at the end of the drive unit acting as a propulsion motor for a ship. . The pod drive is advantageous in that it is flexible and can be azimuth controlled and provides freedom in the position of the main engine. However, the pod drive device is expensive and power transmission causes significant power transmission loss.

  The mechanical propeller drive itself has the distinct advantages of being cheap and simple and having substantially low power transmission losses. However, mechanical propellers have disadvantages as well. The propulsion efficiency is not as desirable and there is a risk of cavitation on the advancing surface when variable pitch propellers are used, especially at low speeds. This occurs when the propeller is driven at low pitch and high rotational speed conditions, thereby reducing the local pressure on the surface of the propeller blades. In addition, the ship maneuverability is substantially inferior.

  A combination of pod drive and mechanical propeller drive at the whole level has been proposed in the document "Hydrodynamics of Fast Rope Vessel" by Raimo Hamalainen. The proposed combination is believed to have several advantages. However, it has been found that this solution does not result in an optimal solution per se, especially in low speed / steering operations. In general, this proposal is promising, but there are still practical problems to be solved.

  It is an object of the present invention to provide a marine vessel propulsion system and method of operation thereof that minimizes the disadvantages of the prior art. In particular, the object of the present invention is to provide a marine vessel hybrid propulsion system that results in excellent overall low speed / steering maneuvering efficiency and operation, as well as reduced propulsion vibration and noise levels, It is to provide a method for operating a marine vessel propulsion system.

  The object of the invention is realized substantially as described in claims 1 and 8 and in more detail in the other claims.

  According to a preferred embodiment of the present invention, the object of the present invention is realized by a marine vessel propulsion system comprising an engine system and several propulsion means for generating a propulsive force at the stern part. The propulsion means includes at least two propulsion arrangements capable of steering action and at least one shaft-driven propeller drive having a variable pitch propeller and substantially adjustable in a feathering state. Includes combinations.

  According to a preferred embodiment of the present invention, the at least two steerable propulsion structures are azimuth type propulsion structures that can comprise a variable pitch propeller system or a constant pitch propeller system. The azimuth type propulsion structure is preferably powered by an electric motor that is powered by a piston engine generator set. The shaft driven propeller drive is mechanically coupled to the piston engine, such as by a gear system. In some cases, a water jet propulsion system may be used as the steerable propulsion structure.

  The propulsion system according to the present invention is configured to be driven differently in different operating modes, specifically in normal / cruising speed operating mode and low speed / harbor maneuvering operating mode. In the normal / cruise speed mode of operation, at least two azimuth type propulsion structures and at least one shaft driven propeller drive are adapted to produce at least thrust for ship navigation. In the low speed / harbor maneuvering mode of operation, only at least two azimuth type propulsion structures are adapted to produce thrust for ship navigation. In this way, the boat maneuvering operation becomes more advantageous. The ship is always steered by at least two steerable propulsion structures, ie azimuth type propulsion structures.

  The pitch angle of the propeller blades of the shaft drive type propeller drive device can be adjusted to be ± 80 ° to 100 ° with respect to the axis perpendicular to the shaft drive type propeller drive device. In practice, this means that the propeller blades are rotated in either direction until they are substantially parallel to the longitudinal axis of the ship. The direction of rotation can be selected according to the shape of the blade so as to minimize flow resistance. Preferably, the engine system comprises gears and coupling means shiftable to a disengaged position that couples the propeller drive shaft to the engine. This provides the advantage that transmission of power to the drive shaft is stopped before and during the propeller is in the feathering state. The propeller drive with the coupling means also allows the engine to remain running while power transmission is cut off. However, it is advantageous to stop the engine, for example to reduce unnecessary emissions.

  According to the method of operation of a marine vessel propulsion system comprising at least two steerable propulsion structures at the stern and at least one shaft-driven propeller drive having a variable pitch propeller, at normal / cruising speed, the propulsive force is Provided by the shaft driven propeller drive and steering propulsion structure. Steering thrust is provided by a steerable propulsion structure. The thrust of the shaft-driven propeller drive device is adjusted mainly by adjusting the pitch angle of the propeller. Further, in low speed and / or harbor maneuvering operation, the shaft-driven propeller drive device is adjusted to be feathered to stop transmission of power to the propeller. This is done by adjusting the pitch angle of the shaft driven propeller.

  While the power supply from the engine system to the propeller drive is turned off, at least two steerable propulsion structures are maintained operating. Transmission of power to the shaft-driven propeller drive adjusts the propeller to feathering by disengaging the engine from the shaft of the shaft-driven propeller drive or in the case of a single engine without a gear system Stop by stopping the engine before.

  The pitch angle of the propeller of the shaft-driven propeller drive device is advantageously adjusted to be + 80 ° to 100 ° or −80 ° to 100 °. The at least two steerable propulsion structures are preferably powered by an electric motor powered by one or more piston engine generator sets. During low speed and / or port maneuvering operations, the piston engine of the piston engine generator set is faster than the idling speed, substantially at the most efficient constant speed, preferably with the power consumption of the propulsion structure. Are operated substantially independently. In this way, the engine can be operated in an optimal environment regardless of the power demand and the current speed of the ship.

  The present invention provides several advantages over the prior art. First, the propulsion system lowers the investment cost compared to conventional diesel-electric propulsion systems. Excellent marine maneuvering characteristics as well as excellent propulsion efficiency for high speed vessels is also provided. In the case of the present invention, in the low speed / steering operation, the engine can operate in an optimum state, and there is no risk of cavitation of the shaft driven propeller drive device. Also, one advantage of the present invention is that the number of diesel generators connected to the network can be changed according to load demand, i.e. the engine can be started or stopped. In this way, the engine load can be held closer to the optimum.

  The invention will now be described by way of example with reference to the accompanying drawings.

  In the figure, with reference to the hull of the reference number 1, only its stern portion is shown. The ship comprises an engine system 2 having a number of piston engine generators 2.1 and a number of piston engines 2.2 mechanically coupled to a shaft driven mechanical propeller drive 3. The shaft-driven propeller drive device 3 includes a gear and a clutch 4, and the engine 2.2 is connected to the drive shaft 5 of the propeller drive device 3 through the gear and the clutch 4. A propeller 6 is connected to the outer end of the drive shaft 5. The shaft drive type propeller system drive device 3 includes a variable pitch propeller 6 and a structure 7 for adjusting the pitch angle A thereof. In the figure, the structure 7 is very simplified. The pitch angle adjustment structure 7 may be a hydraulic or mechanical commercial system known as such. However, the pitch angle adjusting structure 7 is such that the pitch of the propeller can be adjusted to a substantially feathered state. In practice, this means that the mechanism that rotates the propeller blades causes the blades to rotate at a larger angle than normal pitch adjustment. This is described in more detail below with reference to FIG.

  Electric power is generated by the piston engine generator set 2.1 and supplied to the network 8. Power can be sent via the network 8 to a steerable propulsion structure such as a pod drive unit 9. The pod drive unit 9 can rotate about its vertical axis, as indicated by the arrows in the figure. In the present invention, this feature is utilized, so that the pod unit 9 operates as a steering device and the shaft-driven propeller drive device 3 does not have any rudder system.

  The shaft-driven propeller drive device 3 is positioned at the center line of the ship body. If there are several shaft-driven propeller drives, it is desirable to position them symmetrically with respect to the center line of the ship body 1. In the figure, two propulsion structures capable of steering operation, that is, a pod drive device 9 are positioned on both sides of the shaft drive type propeller drive device 3 at substantially the same longitudinal position as the propeller 6 of the shaft drive type propeller drive device 3. .

  In the normal cruise speed state, the shaft-driven propeller drive device 3 and the pod drive device 9 are used to generate a propulsive force for ship navigation. The pod drive 9 includes a variable speed propeller system, and the propulsive force of the pod drive 9 is adjusted by controlling the rotational speed of the propellers. If a variable pitch propeller is provided, the propulsive force can also be controlled by controlling the pitch angle of the propeller. The propulsive force of the shaft-driven propeller drive device 3 is adjusted mainly by adjusting the pitch angle of the propeller. Of course, it is also possible to adjust the rotational speed by adjusting the engine speed.

  In low speed operations where better maneuverability is desired, only the pod drive 9 is used for propulsion. In this mode of operation, the pitch angle of the shaft driven propeller drive is adjusted so that its flow resistance is substantially reduced. This state is shown in FIG. In this way, overall efficiency can be increased. Preferably, the pitch angle (A) of the shaft-driven propeller drive device 3 is adjusted so that the propeller is feathered. In this specification, the term feathering or feathering state refers to the blade angle (A) so that the straight line between the leading and trailing edges of the blade, which is a chord, is approximately parallel to the streamline or the longitudinal axis of the ship. Means to be positioned. The blade angle (A) means an angle between the perpendicular of the drive shaft and the average direction of a straight line connecting the leading edge and the trailing edge of the blade.

  When switching to the low speed / harbor maneuvering operation, first, the power supply to the shaft drive type propeller drive device 3 is stopped. This can be done by shifting the clutch 4 to the disengaged position. After stopping the transmission of power, the propeller of the driving device 3 is adjusted to the feathering state. In this way, it is possible to obtain advantageous features of the propulsion system for low speed / steering operations. During operation, the pod drive 9 is configured such that the piston engine of the piston engine generator set 2.1 has a speed higher than the idling speed, substantially the most efficient constant speed and the power consumption of the propulsion structure 9. Are maintained in a substantially independent manner. This means that the total power generation amount may be larger than the actual power demand amount of the pod driving device 9. It is also advantageous to shut down the engine system 2.2. In accordance with the present invention, in this mode of operation, the engine system 2 is operated in the most advantageous manner resulting in low emissions and vibrations of the boat structure.

  While the invention is not limited to the illustrated embodiments, various modifications of the invention are possible within the scope of the appended claims.

1 schematically shows one embodiment of a propulsion system according to the invention in normal operation. FIG. FIG. 2 shows the propulsion system according to FIG. 1 in low speed / steering operation.

Claims (10)

The stern part of the marine vessel is provided with an engine system (2) for generating a propulsive force and several propulsion means (3, 9) , the propulsion means comprising at least one shaft-driven mechanical propeller drive device (3 ) And at least two electric azimuth propulsion structures (9) located on both sides of the at least one shaft-driven propeller drive device (3) , wherein the at least one shaft-driven propulsion system (9) The mechanical propeller drive (3) has a variable pitch propeller (6) adjustable to the feathering state, and the propulsion system is in two operating modes: normal / cruising speed operating mode and low speed / steering operating mode Arranged to be driven and in the normal / cruise speed mode of operation, the at least one shaft-driven propeller drive (3) and the at least two electric motors Both zimuth type propulsion structures (9) are made to generate thrust to move the vessel, and only two electric azimuth type propulsion structures (9) are used to move the vessel in low speed / steering mode of operation. A marine vessel propulsion system characterized by generating. Marine vessel propulsion system according to claim 1, characterized in that the azimuth type propulsion structure (9) comprises a constant pitch propeller system and / or a variable pitch propeller system . The azimuth type propulsion structure (9) is supplied with electric power by an electric motor supplied with power by a piston engine generator set (2.1), and the shaft-driven propeller driving device is a piston engine (2.2). The marine vessel propulsion system according to claim 1, wherein the marine vessel propulsion system is mechanically coupled to the marine vessel . The pitch angle (A) of the blades of the propeller (6) of the shaft-driven propeller drive (3) can be adjusted to be + 80 ° to 100 ° or −80 ° to 100 °. The marine vessel propulsion system according to claim 1 . The engine system (2) has an engagement means (4) that connects the shaft (5) of the shaft-driven propeller drive device (3) to the engine (2.2) and can be shifted to a non-engagement position. The marine vessel propulsion system according to claim 1, comprising: a marine vessel propulsion system according to claim 1 . The stern part of the marine vessel is provided with an engine system (2) and several propulsion means (3, 9), said engine system (2) having said at least one shaft-driven mechanical propeller drive device (3 And / or a method of operating a marine vessel propulsion system having a propulsive force against the at least two electric azimuth propulsion structures (9) on both sides of the shaft-driven propeller drive (3). One shaft driven mechanical propeller drive (3) has a variable pitch propeller (6) adjustable to the feathering state, and the marine vessel propulsion system has two modes of operation: normal / cruise speed mode of operation And at least one shaft driven propeller drive device (when operated in low speed / steering mode and in normal / cruising speed mode) ) And the at least two electric azimuth propulsion structures (9) generate thrust to move the vessel, and the shaft-driven propeller drive (3) is adjusted to the feathering state in the low speed / steering mode of operation. The transmission of power to the propeller (6) of the shaft-driven propeller drive device (3) is stopped and a thrust is generated to move the ship with only the at least two azimuth type propulsion structures (9). A method for operating a marine vessel propulsion system . Transmission of power to the shaft-driven mechanical propeller drive (3) causes the engine (2.2) to disengage from the shaft (5) of the shaft-driven mechanical propeller drive (3). The operation method of the marine vessel propulsion system according to claim 6, wherein the marine vessel propulsion system is stopped . The marine vessel propulsion system according to claim 6, characterized in that the transmission of power to the shaft-driven mechanical propeller drive (3) is stopped by stopping the engine (2.2). How it works .   In low speed and / or ship maneuvering operation, the pitch angle (A) of the propeller of the shaft-driven propeller means (3) is advantageously adjusted to be between + 80 ° and 100 ° or between −80 ° and 100 °. The operation method of the marine vessel propulsion system according to claim 6. The at least two azimuth type propulsion structures (9) are powered by a motor powered by one or more piston engine generator sets (2.1), and in low speed / harbor maneuvering operation, The piston engine of the piston engine generator set (2.1) is substantially independent of the power consumption of the propulsion structure (9) at a speed higher than the idle speed, substantially the most efficient constant speed. The marine vessel propulsion system operating method according to claim 6, wherein the marine vessel propulsion system operates .

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