U.S. patent application number 14/004376 was filed with the patent office on 2014-03-13 for ship.
This patent application is currently assigned to WOBBEN PROPERTIES GMBH. The applicant listed for this patent is Rolf Rohden. Invention is credited to Rolf Rohden.
Application Number | 20140072460 14/004376 |
Document ID | / |
Family ID | 45876724 |
Filed Date | 2014-03-13 |
United States Patent
Application |
20140072460 |
Kind Code |
A1 |
Rohden; Rolf |
March 13, 2014 |
SHIP
Abstract
The invention concerns a ship comprising at least one electric
motor for driving a ship and a cooling device for cooling the at
least one electric motor by means at least one coolant. It is
further according to the invention that the cooling device has a
heat exchanger adapted to cool the at least one coolant by means of
sea water.
Inventors: |
Rohden; Rolf; (Aurich,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rohden; Rolf |
Aurich |
|
DE |
|
|
Assignee: |
WOBBEN PROPERTIES GMBH
Aurich
DE
|
Family ID: |
45876724 |
Appl. No.: |
14/004376 |
Filed: |
March 15, 2012 |
PCT Filed: |
March 15, 2012 |
PCT NO: |
PCT/EP2012/054570 |
371 Date: |
November 21, 2013 |
Current U.S.
Class: |
417/371 |
Current CPC
Class: |
F04D 13/08 20130101;
B63H 21/17 20130101; B63H 21/383 20130101; H02K 9/00 20130101; H02K
9/10 20130101; H02K 9/08 20130101 |
Class at
Publication: |
417/371 |
International
Class: |
F04D 13/08 20060101
F04D013/08 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 2011 |
DE |
10 2011 005 588.6 |
Claims
1. A ship comprising: a propeller; at least one electric motor for
driving the propeller; and a cooling device that includes a coolant
for cooling the at least one electric motor, the cooling device
including a heat exchanger adapted to cool the coolant by sea
water.
2. The ship according to claim 1 wherein the coolant is at least
one of air and fresh water.
3. The ship according to claim 1 wherein: the coolant is air; and
the electric motor includes a rotor and a stator that are cooled by
said air.
4. The ship according to claim 3 wherein the at least one electric
motor is arranged in a substantially air tight engine room of the
ship, and the air for cooling the electric motor is the air in the
engine room.
5. The ship according to claim 3 further comprising means for
conveying air through the cooling device, wherein the cooling
device includes a cooling air inlet and a warm air outlet of the
electric motor.
6. The ship according to claim 5 further comprising means for
guiding the air that is arranged between a cooling air inlet of an
electric motor and a cooling air outlet of the heat exchanger.
7. The ship according to claim 1 wherein the at least one electric
motor includes a rotor and a stator located in a housing, the
cooling device including cooling passages in at least one of the
housing and the stator of the at least one electric motor.
8. The ship according to claim 7 wherein cooling air can be passed
through at least one of the cooling passages and a gap between the
stator and the rotor.
9. The ship according to claim 7 wherein the coolant is fresh water
that is passed through the cooling passages for cooling the
electric motor.
10. The ship according to claim 3 wherein the heat exchanger is a
first heat exchanger, the cooling device further including a second
heat exchanger coupled to the first heat exchanger, the second heat
exchanger being adapted to cool a coolant by fresh water, wherein
the fresh water is cooled by sea water of the first heat
exchanger.
11. The ship according to claim 10 wherein the first heat exchanger
is coupled to the stator of the electric motor and is adapted to
cool the stator by means of the fresh water.
12. The ship according to claim 1 further including an energy
supply that is cooled by the coolant.
13. The ship according to claim 12 wherein the energy supply has at
least one converter that is cooled by fresh water.
14. A cooling device for a ship comprising: a cooling passage that
includes a coolant for cooling at least one electric motor; and a
heat exchanger located around a portion of the cooling passage and
adapted to cool the coolant using sea water.
15. The cooling device according to claim 14, the coolant is one of
air or fresh water.
16. The cooling device according to claim 14, wherein the cooling
passage includes an inlet and an outlet, at least one of the inlet
and the outlet including a fan for conveying the coolant through
the cooling passage.
17. The cooling device according to claim 14, wherein the cooling
passage is a first cooling passage that includes air as the
coolant, wherein the heat exchanger is a first heat exchanger, the
cooling device further comprising: a second cooling passage that
includes fresh water coolant for cooling the at least one motor;
and a second heat exchanger located around a portion of the second
cooling passage and adapted to cool the fresh water coolant using
sea water.
18. The ship according to claim 5, wherein the means for conveying
air through the cooling device is a fan arranged at least one of
the cooling air inlet and the warm air outlet.
19. The ship according to claim 5 further comprising means for
guiding the air is arranged between a warm air outlet of the
electric motor and a warm air outlet of the heat exchanger.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The invention concerns a ship comprising at least one
electric motor for driving the ship and a cooling device for
cooling the at least one motor by means of a coolant. The invention
further concerns a cooling device for a ship having at least one
electric motor.
[0003] 2. Description of the Related Art
[0004] Hitherto the proportion of ships was implemented
predominantly by means of internal combustion engines. Electric
drives were also quite often used in relation to smaller ships, for
example in the leisure industry. In recent times trials are also
being undertaken to drive larger ships, such as for example for
cargo ships and container ships, by means of electric drives. The
climate at sea represents a problem for those drives which
frequently have a complicated and expensive electronic system. In
particular cooling such electric drives for cargo ships is a
problem which hitherto has been only inadequately resolved.
BRIEF SUMMARY
[0005] One or more embodiment of the present invention is to make a
contribution to resolving that problem, giving in particular an
electric motor-driven ship with improved cooling.
[0006] In a ship of the kind set forth in the opening part of this
specification a cooling device has a heat exchanger adapted to cool
the at least one coolant by means of sea water.
[0007] Accordingly a ship according to one embodiment of the
invention has at least two cooling circuits which are coupled
together. In a first circuit, coolant circulates between the at
least one electric motor and the heat exchanger. In a second
circuit, sea water circulates between the heat exchanger and an
outside region of the ship. The two circuits are separated from
each other by the heat exchanger in such a way that coolant and sea
water do not mix. As a result the at least one electric motor does
not come into contact with sea water. Thus, corrosion of the at
least one electric motor is substantially reduced and as a result
the service life is substantially prolonged. The maintenance
expenditure and complication is also substantially reduced. The
construction and manufacture of such an electric motor is also
simplified as it does not have to be designed for direct cooling
operation by means of sea water. A further advantage is also that a
ship with a drive designed in that way is improved in terms of
energy consumption and reliability. Sea water represents a natural
and almost unlimited cooling resource. The temperature of the sea
water is in that respect substantially constant in a voyage with
the ship so that such a cooling device does not require permanent
adaptive adjustment. In addition there is no need for complicated
cooling apparatuses to be installed on board a ship whereby on the
one hand operational reliability and on the other hand the energy
consumption of such a ship are improved. Preferably the heat
exchanger is in the form of a counter-flow heat exchanger.
Alternatively the heat exchanger is the form of a co-flow heat
exchanger. According to one embodiment of the invention it is also
possible to use a plurality of heat exchangers so that the coolant
can be cooled in a multi-stage heat exchange process.
[0008] In a first preferred embodiment the coolant is air and/or
fresh water. According to the invention the term fresh water here
does not denote sea water but for example cooling water, cooling
fluid and also water-oil emulsions and the like. Air refers here to
space air and not to salty sea air. Those two coolants are
particularly preferred as they are readily available and are
already used in many cases for electric motors. In that respect,
heat exchange of sea water to fresh water is easy to implement by
virtue of good thermal conduction. Especially adapted heat
exchangers are preferably to be used for heat exchange from sea
water to air.
[0009] In a further preferred embodiment the coolant is air and a
rotor and/or a stator of the electric motor can be cooled by means
of said air. In particular air is preferred for cooling a rotor of
an electric motor. The cooled air can be passed for example through
a gap between the rotor and the stator, cooling ribs can be
arranged at the stator, or cooling passages through which the cool
air can be passed are taken through the stator. In addition the air
can be passed into an internal hollow space in the rotor and thus
cool it.
[0010] In a further preferred embodiment the at least one electric
motor is arranged in a substantially air-tightly closed engine room
of the ship and of the air for cooling the electric motor is room
air. Thus the at least one electric motor is not exposed to salty
air whereby corrosion of the motor is substantially avoided. That
provides that on the one hand maintenance of such a motor or a ship
according to the invention having such a motor and such a cooling
device is substantially reduced and the operational reliability of
the ship is improved. In accordance with this preferred embodiment,
each motor can be provided with a dedicated room, or all motors are
arranged jointly in a substantially air-tightly closed room. In
addition an energy supply for the motors can also be arranged in
that room. The heat exchanger can also be arranged in an
air-tightly closed room or can be in fluid communication with that
room in some other way.
[0011] In accordance with a further preferred embodiment means for
conveying air, such as by one or more fans, are arranged at a
cooling air inlet and/or a warm air outlet of the electric motor.
Thus cool air can be guided in specifically targeted fashion to the
electric motor or can be caused to impinge thereagainst. That air
can also be guided in cooling passages, over cooling ribs, in
openings or hollow spaces or the like to the electric motor. In
addition warm air can be carried away from the electric motor in a
specifically targeted fashion. That makes it possible to achieve
specifically targeted cooling of the motor. In addition a
specifically targeted volume flow or a specifically targeted air
speed can be placed over the motor so that it can be cooled in
improved targeted fashion. That makes it possible to increase the
efficiency of the motor and the service life of a motor is
prolonged. The maintenance complication and expenditure is also
further reduced.
[0012] In a further preferred embodiment means for guiding the air
is/are arranged between a cooling air inlet of an electric motor
and a cooling air outlet of the heat exchanger and/or between a
warm air outlet of the electric motor and a warm air outlet of the
heat exchanger. Such means can include for example hoses, passages,
tubes, shafts and so forth. A specifically targeted air feed and
discharge is thus afforded according to the invention and effective
cooling of the motor is improved. Additionally or alternatively the
means for guiding the air can have means for conveying air. In an
embodiment the means for guiding the air are arranged between a
cooling air inlet of the electric motor and a cooling air outlet of
the heat exchanger. In this embodiment cooling air is passed
specifically to the motor by means of the means for guiding the
air, the motor is cooled by means of the air supplied thereto, the
warm air is then discharged into the room which is preferably
air-tightly closed. The heated room air is then cooled again by
means of the exchange effect. In an alternative the means for
guiding the air are arranged between a warm air outlet of the
electric motor and a warm air inlet of the heat exchanger. In this
embodiment the warm air is carried away from the electric motor,
and towards the heat exchanger, by means of which it is cooled. The
cooled air is then discharged into the room which is preferably
air-tightly closed. In a further embodiment the means for guiding
the air are arranged both between a cooling air outlet of the heat
exchanger and a cooling air inlet of the electric motor, and also
between a warm air outlet of the electric motor and a warm air
inlet of the heat exchanger. Accordingly the cooling air circulates
in a substantially closed system. In this embodiment the room does
not have to be air-tightly closed, but rather it is sufficient for
the motors to be protected from salty air.
[0013] In a further preferred embodiment the at least one electric
motor has cooling passages at a housing and/or at a stator. The
cooling passages can pass through the housing and/or along a stator
winding. Specifically targeted cooling of a motor is possible by
means of such cooling passages. The cooling passages can be
designed using various geometries, for example straight, curved, in
a zig-zag shape or also in a different fashion. Ribs can also be
arranged in the passages to achieve still more effective
cooling.
[0014] In a further embodiment cooling air can be passed through
the cooling passages and/or a gap between the stator and a rotor.
That advantageously develops effective cooling of the electric
motor. Means for guiding the air and/or means for conveying the air
for example can be connected to the cooling passages.
[0015] In a further preferred embodiment the coolant is fresh water
which can be passed through the cooling passages for cooling the
electric motor. That permits still more effective cooling of an
electric motor. In this embodiment the fresh water is cooled by
means of the heat exchanger, passed through tubes, hoses or the
like to the passages, passed through the passages and then passed
heated again back to the heat exchanger.
[0016] In a further preferred embodiment the cooling device has a
second heat exchanger which can be connected to a first heat
exchanger and which is adapted to cool air by means of fresh water,
wherein the fresh water can be cooled by means of the first heat
exchanger by means of sea water. Thus fresh water and air can be
cooled with a heat exchanger. It is for example possible to cool
fresh water by sea water with a large primary heat exchanger, and
to pass that fresh water to various motors or other items of
equipment in the ship such as for example the diesel-generating
assemblies. The electric motors can accordingly each have a
respective dedicated second small heat exchanger, by means of which
air is cooled by the cool fresh water. The fresh water can then be
additionally used to cool for example the stator of the motor while
the cooled air is used to be passed through a gap between the rotor
and the stator and thus cool the rotor. In a further preferred
embodiment the first heat exchanger can be connected to a stator of
the electric motor and is adapted to cool it by means of the fresh
water.
[0017] In a further preferred embodiment the energy supply has a
converter and the converter can be cooled by means of fresh water.
In particular it is preferable for those inverters to be cooled by
means of the fresh water as they are preferably arranged in
positional proximity with the electric motors. It is equally
preferable for both the converter cooling or the energy supply
cooling and the electric motor cooling to be arranged on the same
cooling circuit of fresh water. It is however also possible to
provide different cooling circuits.
[0018] In a further aspect of the invention, in a cooling device of
the kind set forth in the opening part of this specification, the
object is attained in that a cooling device is of a configuration
corresponding to one of the above-mentioned embodiments. Such a
cooling device can be used in a large number of ships, marine
vessels or yachts to cool for example electric motors or also other
devices to be cooled. Such a cooling device contributes to making
the ship low-maintenance and operationally reliable and to reduce
energy consumption. All the above-mentioned advantages are achieved
when such a cooling device is used in a ship.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0019] The invention is described hereinafter by means of
embodiments by way of example with reference to the accompanying
drawings in which:
[0020] FIG. 1 shows a partly broken-away perspective view of a ship
according to the invention,
[0021] FIG. 2 shows a diagrammatic view of a first embodiment of a
cooling device,
[0022] FIG. 3 shows a diagrammatic view of a second embodiment of a
cooling device,
[0023] FIG. 4 shows a diagrammatic view of a third embodiment of a
cooling device,
[0024] FIG. 5 shows a diagrammatic view of a fourth embodiment of a
cooling device.
DETAILED DESCRIPTION
[0025] The ship 102 shown in FIG. 1 has on a deck 114 four Magnus
rotors 110 as propulsion devices. Besides the Magnus rotors 110,
the ship also optionally has a bridge 130 as well as a crane 105
and a crane 103 on the deck 114. As a further propulsion device the
ship additionally has a propeller 150 at the stern of the ship 102.
The propeller 150 can be connected by way of a shaft 111 to two
electric motors 108, 109. The electric motors 108, 109 are fed with
electric current by way of two converter cabinets 115, 116.
Arranged above the electric motors 108, 109 and the converter
cabinets 115, 116 is a deck 172 which preferably air-tightly closes
the engine room in relation to a cargo hold. Preferably
large-volume electric motors, for example synchronous machines,
involving a low rotary speed, are used as the electric motors 108,
109 so that a transmission does not necessarily have to be provided
in the overall drive train. The motors can also be operated
selectively. For light to pass into the interior of the ship 102 it
has windows 118 at the sides.
[0026] FIGS. 2 to 4 show embodiments by way of example of a cooling
device according to the invention for a ship 102 according to the
invention, by means of which the electric motors 108, 109 can be
cooled.
[0027] As shown in FIG. 2 the cooling device 1 in the first
embodiment has a heat exchanger 2 which can be fed on one side 4
with a flow 16 of sea water. The flow of sea water is only
diagrammatically indicated here by the arrows. In the case of a
ship 102 as shown in FIG. 1 the sea water flow 16 can be passed to
and away from the heat exchanger 2 by means of tubes. At a second
side 6 the heat exchanger 2 has an air inlet 24 and an air outlet
26. Air can thus be cooled by means of this heat exchanger 2.
[0028] FIG. 2 also shows an electric motor 8. The electric motor 8
has a stator 10 which can have a stator housing. The electric motor
8 also has a rotor which rotates about an axis of rotation 14 in
operation and can be coupled to a drive unit of a ship such as for
example a shaft 111 and propeller 150 (FIG. 1). The electric motor
8 together with its components is arranged in a room 19 which is
substantially air-tightly closed by a wall 18. The heat exchanger 2
together with its components is arranged outside the room 19. The
stator or stator housing 10 of the electric motor 8 also has an air
inlet 20 and an air outlet 22. Arranged thereat as a means for
conveying the air is a respective fan 20a, 22a for conveying the
air into and out of the motor 8; alternatively other pumps such as
vane pumps or the like could be used for that purpose. Preferably
the air can be passed through cooling passages in the stator or the
stator housing 10 and/or a gap between the rotor 12 and the stator
10. A tube 30 is arranged between the air outlet 22 and the air
inlet 24 of the heat exchanger 2. Warm air is carried out of the
motor 8 and passed to the heat exchanger 2 by way of the tube 30.
The cool air which issues from the air outlet 26 of the heat
exchanger 2 is passed by means of a second tube 32 to an air inlet
28 of the room 19 in the wall 18. The air passes out of that air
inlet 28 into the room 19 so that it is overall filled with cool
air. The cool room air is then sucked in by the fan 20a at the air
inlet 20 and is passed into the cooling passages of a gap between
the rotor 12 and the stator 10. By the room 19 being filled with
cool air, the fan 20a in the inlet 20 can suck in air as needed to
cool the motor 8 to a temperature which is preferred for optimum
performance. The motor 8 is also cooled by way of air which is not
blown or sucked directly into the motor 8, but flows along the
surface thereof. Preferably the room 19 is air-tightly closed by
means of the wall 18 or decks, doors, hatches and the like so that
in the case of a ship 102 (FIG. 1) no salty air or as little salty
air as possible passes into the room 19. Alternatively it is also
in accordance with the invention for the room 19 not to be
air-tightly closed, but for an increased pressure to obtain within
the room 19 so that salty air cannot flow from the exterior into
the interior of the room 19. It is also possible for a tube to be
arranged between the inlet 28 of the room 19 and the inlet 20 of
the motor and/or for no tube 30 to be arranged between the outlet
22 of the motor 8 and the inlet 24 of the heat exchanger 2.
[0029] In the second embodiment of the cooling device 1 shown in
FIG. 3 the cooling device 1 has a first heat exchanger 2 and a
second heat exchanger 3. The two heat exchangers 2, 3 are coupled
to a motor 8 and serve to cool it by means of coolant. The first
heat exchanger 2 is arranged in a first cooling circuit which
substantially corresponds to the first embodiment shown in FIG. 2
of the cooling device 1. The second circuit in which the second
heat exchanger 3 is arranged uses fresh water such as for example
cooling water or other cooling fluid as coolant. The second heat
exchanger 3 is coupled like the first heat exchanger 2 to a sea
water flow 17, wherein that sea water flow 17 once again in the
case of a ship 102 as shown in FIG. 1 can be passed for example by
way of tubes from an external region of the ship 102 to the heat
exchanger 3. The heat exchanger 3 is connected at a second side 7
to two cooling water conduits 34, 36 which each have a respective
pump 38, 40. The pumps 38, 40 are adapted to deliver a
corresponding cooling water flow. The cooling water conduits 34, 36
lead from outside the room where the heat exchanger 3 is also
arranged into the interior 19 of the room and are there connected
to a cooling body 42. For that purpose the cooling body 42 has a
cooling water inlet 44 and a cooling water outlet 46. As shown in
FIG. 3 the cooling body 42 is arranged at an outer portion of the
motor housing or the stator 10 of the electric motor 8. That is
only a diagrammatic view. It is also possible to provide in a
housing or in the stator 10, cooling passages through which cooling
water can be passed. In this embodiment it is possible for example
for the rotor 12 to be substantially cooled with the air which can
be passed through the air inlet 20 into the interior of the motor
8, and for the stator 10 of the motor 8 to be cooled substantially
with water which can be cooled by way of the heat exchanger 3 by
means of the sea water flow 17 and which circulates by means of the
cooling water conduits 34, 36 between the heat exchanger 3 and the
cooling body 42.
[0030] FIG. 4 shows a further alternative of a cooling device 1. In
addition to the cooling device 1 shown in FIG. 3 the cooling device
1 of FIG. 4 has a third cooling circuit. The third cooling circuit
is fed like the second cooling circuit by means of the heat
exchanger 3 which is adapted to cool cooling water by means of a
sea water flow 17. As shown in FIG. 4 two further cooling water
conduits 35,37 branch from the cooling water conduits 34, 36 and
pass cooling water to and away from a converter cabinet 48. The
converter cabinet 48 is connected to the electric motor 8 by way of
a power supply cable 50. Arranged in the converter cabinet 48 is a
plurality of converters adapted to provide electric current at a
voltage and a frequency which are required by the electric motor 8.
To ensure optimum operation of a converter cabinet 48 it is
preferable for it to be cooled. In the illustrated embodiment the
converter cabinet 48 or the converters contained therein is cooled
with cooling water cooled by means of the heat exchanger 3 by means
of a sea water flow 17. The cooled cooling water is conveyed on a
second side 7 of the heat exchanger 3 by a pump 40, and flows
through a cooling water feed conduit 37 to the converter cabinet
48. A plurality of cooling bodies can be arranged therein, or
plates or the like which transport heat away from the converters.
The heated water is then conveyed away from the converter cabinet
48 by means of the cooling water conduit 35 and the pump 38 and
passes to the heat exchanger 3 again. The two further cooling
circuits are of a configuration corresponding to the circuits in
FIG. 3.
[0031] A further alternative of the cooling device 1 is shown as an
embodiment in FIG. 5. In this embodiment (FIG. 5) the cooling
device 1 has substantial features in common with the embodiment of
FIG. 3. The circuits used for cooling the electric motor 8 in the
embodiment of FIG. 5 are in cascade relationship. The cooling
device has a first heat exchanger 2 and a second heat exchanger 3.
The heat exchanger 3 has a first side 5 and a second side 7,
wherein a sea water flow 17 can be passed into the first side 5 and
cooling water conduits 34, 36 are connected to the second side. The
first heat exchanger 2 also has a first side 4 and a second side 6,
with two cooling water conduits 52, 54 being connected to the first
side 4 and two air passages 30, 32 to the second side 6. The
cooling water conduit 52, 54 lead to the second side 7 of the
second heat exchanger 3. The co-operation of the air passages 30,
32 with the electric motor 8 and the cooling passages 34, 36 with
the cooling element 42 are of a configuration corresponding to the
embodiment of FIG. 3. In the present embodiment (FIG. 5) a sea
water flow 17 is used to cool cooling water which then is used on
the one hand to cool the electric motor 8 by way of a cooling body
42 and on the other hand is used in the first heat exchanger 2 to
cool air which then in turn is used to cool the electric motor 8
and in particular the rotor 12. Thus only one sea water access is
necessary for the overall cooling system and in addition corrosion
in the first heat exchanger 2 can be very substantially
avoided.
[0032] If more than one motor 8, 108, 109 is arranged in a ship 102
(FIG. 1), a cooling device can be provided for each motor or a
common cooling device can be provided for a plurality of motors. If
a cooling device is designed for a plurality of motors as in the
embodiment of FIG. 5 a first heat exchanger 2 can be arranged for
example for each electric motor 8, 108, 109, in which case that
plurality of first heat exchangers 2 co-operative with a single
second heat exchanger 3.
[0033] The various embodiments described above can be combined to
provide further embodiments. All of the U.S. patents, U.S. patent
application publications, U.S. patent application, foreign patents,
foreign patent application and non-patent publications referred to
in this specification and/or listed in the Application Data Sheet
are incorporated herein by reference, in their entirety. Aspects of
the embodiments can be modified, if necessary to employ concepts of
the various patents, application and publications to provide yet
further embodiments.
[0034] These and other changes can be made to the embodiments in
light of the above-detailed description. In general, in the
following claims, the terms used should not be construed to limit
the claims to the specific embodiments disclosed in the
specification and the claims, but should be construed to include
all possible embodiments along with the full scope of equivalents
to which such claims are entitled. Accordingly, the claims are not
limited by the disclosure.
* * * * *