NO20170979A1

NO20170979A1 - Vessel Arrangement

Info

Publication number: NO20170979A1
Application number: NO20170979A
Authority: NO
Inventors: Henning Borgen
Original assignee: Vard Electro As
Priority date: 2017-06-15
Filing date: 2017-06-15
Publication date: 2018-12-17

Abstract

A vessel (100) having an internal moon pool (10), a fluid channel (11,21) extending from the moon pool (10) to an outside of the vessel (100), a fluid turbine unit (13,23) arranged 5 in the fluid channel (11,21), the fluid turbine unit (13,23) comprising a fluid turbine (14) coupled to a generator (15).

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 an internal moon pool, a fluid channel extending from the moon pool to an outside of the vessel, a fluid turbine unit arranged in the fluid channel, the fluid turbine unit comprising a fluid turbine coupled to a generator.

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 vessel according to an embodiment,

Figure 2 illustrates a vessel according to an embodiment,

Figure 3 illustrates a vessel according to an embodiment,

Figure 4 illustrates a turbine unit according to an embodiment,

Figure 5 illustrates a power distribution network for a vessel, and

Figure 6 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 moon pool 10 enclosed within its hull structure, where the moon pool 10 permits access to, for example, lower equipment or tools through the moon pool 10 to a subsea location. This may be, for example, subsea wellhead equipment, a remotely operated vehicle (ROV), a sea floor robot, or any other item needing to be deployed or suspended from the vessel 100 into the sea.

The vessel 100 has first and second fluid channels 11,21 extending from the moon pool 10 to an outside of the vessel 100. The moon pool 10 is otherwise a substantially closed volume, being defined by the hull structure of the vessel 100 and the water 101 on which the vessel 100 floats.

A fluid turbine unit 13,23 is arranged in each fluid channel 11,21. With reference to Fig.4, each fluid turbine unit 13,23 comprises a fluid turbine 14 coupled to a generator 15. In the embodiment described here, the generator 15 is an electric generator, however other types of generators are also possible, for example hydraulic generators. A control unit 25 is arranged with the generator 15 and configured for regulating a torque acting from the generator 15 on the turbine 14. This allows regulation of the resistance from the fluid turbine 14 on a fluid flow through the channel 11,21, as well as optimisation of the operation of the turbine unit 13,23 so as to maximise power extracted.

The fluid turbine unit 13,23 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.

Again referring to Fig.1, as the vessel 100 heaves in the water, the water column in the moon pool 10 will fluctuate upwards and downwards, as indicated by the double arrow. This movement forces air present in the moon pool 10 cyclically through the fluid channels 11,21 and past the turbine units 13,23, during which power can be generated by the generator 15.

In one embodiment, illustrated in Fig.2, the vessel 100 comprises a ventilation shaft 30 having a valve 31. The ventilation shaft 30 extends from the moon pool 10 to the outside of the vessel 100. By means of the ventilation shaft 30, an opening to the outside atmosphere can be selectively provided, for example to avoid (or reduce) pressure fluctuations in the moon pool 10 when workers are carrying out operations in the moon pool 10 area, or when no power generation through the turbine units 13,23 is required. Alternatively, the turbine units 13,23 and/or the channels 11,21 can be arranged so that they selectively provide a free opening to the outside atmosphere, for example by letting air bypass the turbine units 13,23, for the same purpose.

In one embodiment, illustrated in Fig.3, the first fluid channel 11 comprises a first one-way valve 19 permitting flow from the moon pool 10 to the outside of the vessel 100 and the second fluid channel 21 comprises a second one-way valve 39 permitting flow from the outside of the vessel 100 to the moon pool 19.

This ensures that air drawn into the moon pool 10 flows through the second channel 21 and past the second turbine unit 23, while air flowing out of the moon pool 10 flows through the first channel 11 and past the first turbine unit 11. This allows the turbine units 13,23 to be optimised in their design for handling flow in one direction only, which allows for a more efficient design. (As opposed to a turbine unit having to be designed for flow in both directions.)

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. This energy may, for example, be utilised by the vessel, as described below.

The vessel 100 may have a power distribution network 51, illustrated in Fig.5, where at least one turbine unit 13,23 is operatively coupled to the power distribution network 51 such as to allow power generated by the turbine unit 13,23 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.5, 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.5, 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. 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 hybridelectric vessels with only minor emergency generator power).

The turbine unit 13,23 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 can be configured to have a fixed direction of rotation, independent of the direction of fluid flow through the turbine unit 13,23. 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 11,21 (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 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 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 11,21. 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:

an internal moon pool (10),

a fluid channel (11,21) extending from the moon pool (10) to an outside of the vessel (100),

a fluid turbine unit (13,23) arranged in the fluid channel (11,21), the fluid turbine unit (13,23) comprising a fluid turbine (14) coupled to a generator (15).

2. A vessel (100) according to claim 1, wherein the generator (15) is an electric generator.

3. A vessel according to claim 1 or 2, wherein the fluid turbine unit (13,23) comprises a control unit (25) configured for regulating a torque acting from the generator (15) on the turbine (14).

4. A vessel (100) according to any preceding claim, wherein the vessel (100) comprises a ventilation shaft (30) having a valve (31) disposed therein, the ventilation shaft (30) extending from the moon pool (10) to the outside of the vessel (100).

5. A vessel (100) according to any preceding claim, further comprising a power distribution network (51), whereby the fluid turbine unit (13,23) is operatively coupled to the power distribution network (51) such as to allow power generated by the fluid turbine unit (13,23) to be supplied to the power distribution network (51).

6. 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).

7. A vessel according to any preceding claim, wherein the fluid turbine unit (13,23) comprises a guide vane (26a,26b) arranged to guide a fluid towards the fluid turbine (14).

8. A vessel according to any preceding claim, wherein the fluid turbine unit (13,23) is a bi-directional fluid turbine unit.

9. 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).

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

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

12. A vessel according to claim 10, wherein the fluid turbine unit (13,23) 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) and the pitch controller (25) arranged to control the pitch of the blades in response to the signal.

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

14. A vessel (100) according to any preceding claim, wherein the fluid channel (11,21) is a first fluid channel (11) and the vessel (100) comprises a second fluid channel (21) extending from the moon pool (10) to an outside of the vessel (100) and having a fluid turbine unit (23) arranged therein, wherein

the first fluid channel (11) has a first one-way valve (19) therein, permitting flow from the moon pool (10) to the outside of the vessel (100) and

the second fluid channel (21) has a second one-way valve (39) therein, permitting flow from the outside of the vessel (100) to the moon pool (19).