NO20170978A1

NO20170978A1 - Vessel Arrangement

Info

Publication number: NO20170978A1
Application number: NO20170978A
Authority: NO
Inventors: Sigbjørn Akselvoll
Original assignee: Vard Electro As
Priority date: 2017-06-15
Filing date: 2017-06-15
Publication date: 2018-12-17
Also published as: NO344172B1

Abstract

A vessel (100) having a stabilization arrangement, the stabilization arrangement having a first tank (10) and a second tank (11), each of the first and second tanks (10,11) configured to hold a water column, a channel (12,22) connecting the first tank (10) to the second tank (11), and a turbine unit (13,23,33,34) arranged in the channel (12,22).

Description

VESSEL ARRANGEMENT

The present invention relates to an arrangement for a vessel, such as a ship, and more particularly to systems and methods for the operation of a vessel.

BACKGROUND

The maritime industry faces continuous demands for improved technology in relation to the operation of ships or other types of vessels, such as rigs or special-purpose vessels. This includes, for example, requirements for improved safety, improved energy efficiency and reduced emissions levels, resulting from both regulatory and market demands.

For example, various configurations of hybrid or full-electric propulsion systems have been proposed and/or developed. Also, alternative energy sources, such as LNG, are being investigated, as well as utilisation of renewable resources, both directly, for example through Flettner rotors, or indirectly through, for example, sustainable fuels such as hydrogen or biofuels.

The inventors are also involved in various such initiatives, and the present invention has the objective to provide systems and methods for the design and/or operation of ships which provides advantages over known solutions and techniques in terms of energy efficiency, safety, passenger or crew comfort, or other aspects.

SUMMARY

In an embodiment, there is provided a vessel having a stabilization arrangement, the stabilization arrangement having a first tank and a second tank, each of the first and second tanks configured to hold a water column, and a first channel connecting a lower part of the first tank to a lower part of the second tank, wherein the vessel comprises at least one of:

- a first turbine unit arranged in the first channel;

- a second channel arranged to connect an upper part of the first tank to an upper part of the second tank, and a second turbine unit arranged in the second channel;

- a third turbine unit arranged in the upper part of the first tank;

- a fourth turbine unit arranged in the upper part of the second tank.

The appended dependent claims outline further embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present invention will now be described with reference to the appended drawings, in which:

Figure 1 illustrates a stabilization arrangement for a vessel according to an embodiment.

Figure 2 illustrates a stabilization arrangement for a vessel according to an embodiment.

Figure 3 illustrates a stabilization arrangement for a vessel according to an embodiment.

Figure 4 illustrates a stabilization arrangement for a vessel according to an embodiment.

Figure 5 illustrates a turbine unit according to an embodiment.

Figure 6 illustrates a power distribution network for a vessel.

Figure 7 illustrates a stabilization arrangement for a vessel according to an embodiment.

Figure 8 illustrates a stabilization arrangement for a vessel according to an embodiment.

Figure 9 illustrates a turbine unit according to an embodiment.

DETAILED DESCRIPTION

Figure 1 shows a sectional, cut view of a vessel 100 according to one embodiment. The vessel 100 has a roll stabilization arrangement with a first tank 10 and a second tank 11, which are configured to hold a water column. A channel 12 connects a lower part 10a of the first tank 10 to a lower part 11a of the second tank 11. Such a roll stabilisation arrangement will be familiar to those skilled in the art; as the vessel 100 rolls, the fluid (typically water) in the tanks 10,11 and the channel 12 will move cyclically between the tanks 10,11 with the same frequency as the roll motion. The tanks 10,11 are designed such that the movement of the water is out of phase with the roll motion, and such that the tanks produce a righting moment on the ship. The tanks 10,11 and the channel 12 may be placed above or below the ship’s metacentre (roll centre) 101. Generally, such a passive roll stabilisation arrangement can reduce roll by typically 40-60%.

According to the embodiment shown in Fig.1, a liquid turbine unit 13 is arranged in the channel 12. The liquid turbine unit 13 may be any type of rotodynamic machinery, for example can the liquid turbine unit 13 comprise a water turbine, a propeller, or the like. Some embodiments of turbine units 13 will be described below.

Figure 2 shows an alternative embodiment, where the vessel 100 has a second channel 22 arranged to connect an upper part 10b of the first tank 10 to an upper part 11b of the second tank 11. A gas turbine unit 23 is arranged in the second channel 22. In this embodiment, no liquid turbine unit is arranged in the channel 12. The tanks 10,11 and the channels 12, 22 form a closed volume, such that a liquid movement from e.g. the first tank 10 to the second tank 11 will force an equivalent volume of gas (generally air) through the second channel 22 and through the gas turbine unit 23. The gas turbine unit 23 may be of various different designs and many types of rotodynamic machinery may be suitable for this purpose.

Fig. 3 shows yet another embodiment according to the present invention. In Fig. 3, a gas turbine unit 33 is arranged in the upper part 10b of the first tank 10 and another gas turbine unit 34 arranged in the upper part 11b of the second tank 11. The tanks 10,11 are open to the atmosphere by vent ducts 35 and 36, respectively. As above, as the water moves between the tanks 10,11, air will be forced through the turbine units 33,34.

In the embodiment shown in Fig.3, a liquid turbine unit 13 is arranged in the channel 12, in addition to the turbine units 33,34. This is optional, however may be advantageous in that the operation of the individual turbines may be controlled in the most efficient or optimal manner.

Fig. 4 shows another embodiment, wherein a liquid turbine unit 13 is arranged in the channel 12 and gas turbine units 23 are arranged in the second channel 22.

Fig. 5 illustrates one possible embodiment of a turbine unit 13,23,33,34. In this embodiment, the turbine unit 13,23,33,34 comprises a propeller 14 coupled to an electric generator 15. Any type of fluid turbine 14 may be used, and this unit may be chosen based on the fluid (gas or liquid) and projected flow rates through the turbine unit, using conventional design methods. The generator 15 may be electric, as in this embodiment, but may also be of a different type, such as a hydraulic generator.

By means of any of the embodiments described above, it is therefore possible to generate power, such as electric power, from the oscillating fluid flow through one or more of the turbine units 13,23,33,34. This energy may, for example, be utilised by the vessel, as described below.

One or more of the turbine units 13,23,33,34 may further comprise a control unit 25 which is configured for regulating the torque acting from the generator 15 on the turbine 14. In this manner, the flow resistance through the turbine unit 13,23,33,34 can be regulated, and thereby the electrical power generated as well as the damping effect of the roll stabilization arrangement on the vessel. In an electric machine, for example, the torque can be regulated very accurately and very quickly. By permitting control of this variable, improved stabilisation performance can be achieved. Additionally, or alternatively, the amount of energy extracted from the oscillating fluid can be maximised for any operating conditions of the vessel.

The turbine unit 13,23,33,34 may further comprise a guide vane 26a,26b arranged to guide a fluid towards the fluid turbine 14. This may be arranged so as to give a narrower or smaller flow path for the fluid past the turbine 14, and thereby improved performance in terms of, for example, power generated or controllability of the flow resistance.

The vessel 100 may have a power distribution network 51, illustrated in Fig. 6, where at least one turbine unit 13,23,33,34 is operatively coupled to the power distribution network 51 such as to allow power generated by the turbine unit 13,23,33,34 to be supplied to the power distribution network 51. The vessel 100 may, for example, have engine generators 52,53, such as diesel engines, operatively coupled to the power distribution network 51 in the usual manner. Alternatively, or additionally, the vessel 100 may have one or more battery units operatively coupled to the power distribution network 51. In the illustrated embodiment shown in Fig.6, one battery 54 is coupled to the power distribution network 51 via an DC/AC converter 55. The vessel’s 100 propulsion machines 56,57 may further be operatively coupled to the power distribution network 51. In the illustrated embodiment shown in Fig.6, the propulsion machines 56,57 are electric motors coupled via shafts to propellers 56a and 57a.

By means of such an arrangement, one can, for example, reduce the load on the engine generators 52,53, or the battery 54, by utilising power generated by the turbine unit 13,23,33,34. This therefore provides advantages of, for example, reduced fuel consumption, reduced emissions, and/or longer battery life. The latter may be particularly advantageous on full-electric vessels (or hybrid-electric vessels with only minor emergency generator power).

In one embodiment, illustrated in a top view of the stabilization arrangement in Fig. 7, the vessel 100 comprises dual channels 12 and 42 connecting a lower part 10a of the first tank 10 to a lower part 11a of the second tank 11. A turbine unit 13 is arranged in channel 12, and one turbine unit 43 is arranged in channel 42. Channel 12 in this embodiment comprises a one-way valve 19 permitting flow only from the second tank 11 to the first tank 10, and channel 42 comprises a one-way valve 39 permitting flow only from the first tank 10 to the second tank 11.

This allows each turbine unit 13,43 to be optimised for the given flow direction, and avoids the need for the turbine unit 13,43 to handle flow in both directions. An equivalent arrangement can be used for the air channel, i.e. the connection between the upper parts of the tanks 10,11.

The tanks 10,11 and the channels 12,22,42 may be arranged spaced in a direction abeam the vessel 100, e.g. located on either side of the vessel. In this case, the channel 12,22,42 may extend between the tanks 10,11 perpendicularly to the longitudinal direction (or nominal direction of travel) of the vessel 100. This is the configuration illustrated in the embodiments described above. In this configuration, the stabilization arrangement may reduce roll motion, and generate power based on the roll forces acting on the vessel 100.

Alternatively, or additionally, the tanks 10,11 may be spaced in a longitudinal direction of the vessel 100. This is illustrated in Fig.8. In this embodiment, the pitch motion of the vessel 100 may be damped and/or power may be generated based on pitch forces acting on the vessel 100. This embodiment may be particularly advantageous, for example, in stand-by or offshore supply vessels, which spend large amounts of operating time in stand-by mode. In this mode, the ship may control the yaw to weather vane into the incoming waves, thereby reducing roll, however the pitch motion may be a considerable discomfort for the crew. Further, according to this embodiment, the fuel consumption of the vessel 100 may be reduced during such stand-by mode.

The turbine unit 13,23,33,34 can be a bidirectional turbine, i.e. a turbine configured for conversion of energy from an oscillating fluid stream. In one embodiment, the turbine unit 13,23,33,34 can be configured to have a fixed direction of rotation, independent of the direction of fluid flow through the turbine unit 13,23,33,34. This may be achieved, for example, by means of a Wells turbine or a Darrieus turbine. This provides the advantage that no moving parts are present in the channel 12,22,42 (with the exception of the rotary part of the turbine unit itself), which improves system reliability. In an alternative embodiment, the turbine unit 13,23,33,34 may have a propeller 14 with variable pitch blades. The variable pitch blades may be actively controlled, or they may be passively controlled via the fluid stream, e.g. with a pivot so that the blades automatically turn in response to a change in fluid flow direction.

An embodiment with variable pitch blades is illustrated in Fig.9. The fluid turbine 14’ has controllable-pitch blades. A pitch controller, in this embodiment embedded in the control unit 25, controls the pitch of the blades. This permits the use of an optimal pitch for any operating condition, such as to maximize power generation or to obtain any desirable dampening performance by using the pitch to adjust the resistance for the fluid in the channel.

Preferably, the blades can be rotated at least 180 degrees. This allows the generator 15 to maintain a given rotational direction, while the blade pitch is used to account for directional changes in the flow. This allows a more optimized generator design, in that it does not have to be designed for oscillating operation with changes in the rotational direction.

The pitch may be actively controlled via the pitch controller based on a sensor reading of the fluid flow in the channel 30,31. The sensor 27 may be a flow meter, or any other sensor capable of providing a signal which is indicative of the flow in the channel. Alternatively, the pitch can be passively controlled, i.e. that the fluid flow itself turns the blades as the fluid flow oscillates.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

The present invention is not limited to the embodiments described herein; reference should be had to the appended claims.

Claims

1. A vessel (100) having a stabilization arrangement, the stabilization arrangement having a first tank (10) and a second tank (11), each of the first and second tanks (10,11) configured to hold a water column, and a first channel (12) connecting a lower part (10a) of the first tank (10) to a lower part (11a) of the second tank (11),

wherein the vessel comprises at least one of:

- a first turbine unit (13) arranged in the first channel (12);

- a second channel (22) arranged to connect an upper part (10b) of the first tank (10) to an upper part (11b) of the second tank (11), and a second turbine unit (23) arranged in the second channel (22);

- a third turbine unit (33) arranged in the upper part (10b) of the first tank (10); and

- a fourth turbine unit (34) arranged in the upper part (11b) of the second tank (11),

and wherein the first, second, third and/or fourth turbine unit (13,23,33,34) each comprises a fluid turbine (14) coupled to a generator (15).

2. A vessel (100) according to claim 1, further comprising a power distribution network (51), whereby at least one of the first, second, third of fourth turbine unit (13,23,33,34) is operatively coupled to the power distribution network (51) such as to allow power generated by the turbine unit (13,23,33,34) to be supplied to the power distribution network (51).

3. A vessel (100) according to the preceding claim, comprising at least one of:

an engine generator (52,53) operatively coupled to the power distribution network (51),

a battery unit (54,55) operatively coupled to the power distribution network (51), and

a propulsion machine (56,57) operatively coupled to the power distribution network (51).

4. A vessel according to any of claims 1-3, wherein the first, second, third and/or fourth turbine unit (13,23,33,34) comprises a control unit (25) configured for regulating a torque acting from the generator (15) on the turbine (14).

5. A vessel according to any of claims 1-4, wherein the first, second, third and/or fourth turbine unit (13,23,33,34) comprises a guide vane (26a,26b) arranged to guide a fluid towards the fluid turbine (14).

6. A vessel (100) according to any preceding claim, wherein the first tank (10) and the second tank (11) are spaced in a direction abeam the vessel (100).

7. A vessel (100) according to any preceding claim, wherein the first tank (10) and the second tank (11) are spaced in a longitudinal direction of the vessel (100).

8. A vessel (100) according to any preceding claim, comprising a third channel (42) connecting a lower part (10a) of the first tank (10) to a lower part (11a) of the second tank (11) and a fifth turbine unit (43) arranged in the third channel (42); wherein

the first channel (12) comprises a one-way valve (19) permitting flow from the second tank (11) to the first tank (10), and

the third channel (42) comprises a one-way valve (39) permitting flow from the first tank (10) to the second tank (11).

9. A vessel (100) according to any preceding claim, comprising a fourth channel connecting an upper part (10b) of the first tank (10) to an upper part (11b) of the second tank (11) and a sixth turbine unit arranged in the fourth channel; wherein

the second channel (22) comprises a one-way valve permitting flow from the second tank (11) to the first tank (10), and

the fourth channel comprises a one-way valve permitting flow from the first tank (10) to the second tank (11).

10. A vessel according to any preceding claim, wherein the first, second, third and/or fourth turbine unit (13,23,33,34) is a bi-directional turbine unit.

11. A vessel according to the preceding claim, wherein the fluid turbine (14) is configured to have a fixed direction of rotation, independent of the direction of fluid flow through the turbine unit (13,23,33,34).

12. A vessel according to any preceding claim, wherein the fluid turbine (14) comprises variable pitch blades.

13. A vessel according to claim 12, wherein the blades are arranged on a pivot and are configured to be passively controlled by a fluid stream through the respective turbine unit (13,23,33,34).

14. A vessel according to claim 12, wherein the first, second, third and/or fourth turbine unit (13,23,33,34) comprises a pitch controller (25) and a sensor (27), the sensor (27) arranged to provide a signal indicative of the fluid flow rate through the respective turbine unit (13,23,33,34) and the pitch controller (25) arranged to control the pitch of the blades in response to the signal.

15. A vessel according to any preceding claim, wherein the fluid turbine (14) comprises fixed pitch blades.