U.S. patent application number 11/289550 was filed with the patent office on 2006-05-18 for boat propulsion system.
Invention is credited to Gunter Ries, Bernd Wacker.
Application Number | 20060105642 11/289550 |
Document ID | / |
Family ID | 7707503 |
Filed Date | 2006-05-18 |
United States Patent
Application |
20060105642 |
Kind Code |
A1 |
Ries; Gunter ; et
al. |
May 18, 2006 |
Boat propulsion system
Abstract
A marine propulsion system may include at least one electric
motor and a converter-fed electrical power supply. The at least one
electric motor may be arranged in a propeller shaft pipe at a stern
of a vessel for driving at least one vessel propeller, and may
include at least one drive machine for driving at least one
generator.
Inventors: |
Ries; Gunter; (Erlangen,
DE) ; Wacker; Bernd; (Herzogenaurach, DE) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O.BOX 8910
RESTON
VA
20195
US
|
Family ID: |
7707503 |
Appl. No.: |
11/289550 |
Filed: |
November 30, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10497141 |
May 28, 2004 |
7018249 |
|
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PCT/DE02/04284 |
Nov 21, 2002 |
|
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11289550 |
Nov 30, 2005 |
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Current U.S.
Class: |
440/6 |
Current CPC
Class: |
F17C 2203/0391 20130101;
B63H 2005/1258 20130101; B63H 21/17 20130101; Y02T 70/5263
20130101; F17C 2270/0509 20130101; B63H 5/125 20130101; B63H 23/24
20130101; F17C 2203/0687 20130101; H02K 7/14 20130101; F01P 3/12
20130101; F17C 13/087 20130101; F01P 2003/2278 20130101; F25B 9/14
20130101; Y02T 70/50 20130101; F01P 2050/02 20130101; Y02E 60/32
20130101; B63H 2021/173 20130101; F17C 2223/0161 20130101; Y02E
60/321 20130101; B63J 2/06 20130101; H02K 16/00 20130101; H02K
55/04 20130101; F17C 2205/0176 20130101 |
Class at
Publication: |
440/006 |
International
Class: |
B63H 21/17 20060101
B63H021/17 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 29, 2001 |
DE |
10158758.9 |
Claims
1. A marine propulsion system, comprising: at least one electric
motor arranged in a propeller shaft pipe at a stern of a vessel for
driving at least one vessel propeller; a converter-fed electrical
power supply to supply electric power to the at least one electric
motor, including, at least one drive machine for driving at least
one generator, wherein at least one of the at least one electric
motor and the at least one generator is a three-phase synchronous
machine, and at least one of the at least one electric motor and
the at least one generator includes a rotating field winding
composed of high-temperature superconductor (HTSL) wire, each
rotating field winding being arranged in a cryostat for
cryogenically cooling the rotating field winding to a temperature
between 15 and 77 K.
2. The marine propulsion system as claimed in claim 1, wherein at
least one of the at least one electric motor and the at least one
generator includes an air gap three-phase winding composed of
loomed copper conductors, arranged in an annular gap between a
rotor and a laminated magnetic iron yoke.
3. The marine propulsion system as claimed in claim 1, wherein the
HTSL wire of the rotating field winding is formed from
multifilament ribbon conductors Bi.sub.2 Ba.sub.2 Sr.sub.2 Cu.sub.3
O.sub.x or B.sub.2 Ba.sub.2 SrCu.sub.2 Ox in at least one of a
silver and silver-alloy matrix, of YBa.sub.2 Cu.sub.3 O.sub.x as a
thin film on a steel strip, a nickel strip, a strip composed of an
alloy containing nickel, a silver strip or an MgB.sub.2
superconductor.
4. The marine propulsion system as claimed in claim 2, wherein the
rotor, including the rotating field winding composed of HTSL wire,
includes 6 to 12 poles.
5. The marine propulsion system as claimed in claim 1, wherein each
cryostat is suppliable with coolant via a coolant circuit.
6. The marine propulsion system as claimed in claim 1, wherein
cryostats are suppliable with coolant via at least two redundant
coolant circuits.
7. The marine propulsion system as claimed in claim 5, wherein at
least one of cold helium and hydrogen gas is provided as the
coolant in the coolant circuit between a cold head and a transfer
coupling to the cryostat.
8. The marine propulsion system as claimed in claim 5, wherein the
coolant circuit between a cold head and a transfer coupling to the
cryostat is designed such that the transfer coupling is supplied
with a liquid coolant including at least one of liquid neon, liquid
hydrogen, liquid nitrogen and a liquefied gas mixture, and
vaporized coolant is fed back to the cold head.
9. The marine propulsion system as claimed in claim 7, wherein the
cold head of each coolant circuit is operatable via a closed-cycle
compressed-gas circuit.
10. The marine propulsion system as claimed in claim 9, wherein the
compressed-gas circuit for the cold head is cooled by at least one
of a central cooling water supply, sea water, and a heat exchanging
device connected to outer surfaces of the vessel over which sea
water washes.
11. The marine propulsion system as claimed in claim 7, wherein
each cold head is associated with a respective compressed-gas
circuit.
12. The marine propulsion system as claimed in claim 9, wherein
each compressed-gas circuit includes an associated integrated
sea-water cooling circuit.
13. The marine propulsion system as claimed in claim 9, wherein
each compressed-gas circuit includes an associated integrated
fresh-water circuit, with a heat exchanger to transfer heat from
the compressed-gas circuit to the integrated fresh-water
circuit.
14. The marine propulsion system as claimed in claim 13, wherein
the integrated fresh-water circuit includes another heat exchanger
to thermally connect the integrated fresh-water circuit to sea
water.
15. The marine propulsion system as claimed in claim 1, wherein the
electrical power supply includes a power machine and a generator
having a cryostat, including a rotating field winding and is
suppliable with coolant by a coolant circuit shared by the cryostat
of the electric motor and the cryostat of the electrical power
supply.
16. The marine propulsion system as claimed in claim 1, wherein the
electrical power supply includes a power machine and a generator
having a cryostat, including a rotating field winding and is
suppliable with coolant by two coolant circuits, which are mutually
redundant and are shared by cryostat of the electric motor and the
cryostat of the electrical power supply.
17. The marine propulsion system as claimed in claim 7, wherein the
cold head in each coolant circuit is arranged in the vertical
direction above that cryostat which is arranged at the highest
point in the vertical direction.
18. The marine propulsion system as claimed in claim 2, wherein the
rotor, including the rotating field winding composed of HTSL wire,
includes 8 poles.
19. The marine propulsion system as claimed in claim 6, wherein at
least one of cold helium and hydrogen gas is provided as the
coolant in the coolant circuit between a cold head and a transfer
coupling.
20. The marine propulsion system as claimed in claim 5, wherein the
coolant circuit between a cold head and a transfer coupling to the
cryostat is designed such that the transfer coupling is supplied
with a liquid coolant including at least one of liquid neon, liquid
hydrogen, liquid nitrogen and a liquefied gas mixture, and
vaporized coolant is fed back to the cold head.
21. The marine propulsion system as claimed in claim 8, wherein the
cold head of each coolant circuit is operable via a closed-cycle
compressed-gas circuit.
22. A marine propulsion system, comprising: at least one electric
motor, arranged as an in-board motor, and for driving at least one
vessel propeller associated therewith via a drive shaft system; and
a converter-fed electrical power supply to supply electric power to
the at least one electric motor; the converter-fed electrical power
supply including, at least one drive machine for driving at least
one generator, wherein at least one of the at least one electric
motor and the at least one generator is a three-phase synchronous
machine, and at least one of the at least one electric motor and
the at least one generator includes a rotating field winding
composed of high-temperature superconductor (HTSL) wire, each
rotating field winding being arranged in a cryostat for
cryogenically cooling the rotating field winding to a temperature
between 15 and 77 K.
23. The marine propulsion system as claimed in claim 22, wherein at
least one of the at least one electric motor and the at least one
generator includes an air gap three-phase winding composed of
loomed copper conductors, arranged in an annular gap between a
rotor and a laminated magnetic iron yoke.
24. The marine propulsion system as claimed in claim 22, wherein
the HTSL wire of the rotating field winding is formed from
multifilament ribbon conductors Bi.sub.2 Ba.sub.2 Sr.sub.2 Cu.sub.3
O.sub.x or B.sub.2 Ba.sub.2 SrCu.sub.2 O.sub.x in at least one of a
silver and silver-alloy matrix, of YBa.sub.2 Cu.sub.3 Ox as a thin
film on a steel strip, a nickel strip, a strip composed of an alloy
containing nickel, a silver strip or an MgB.sub.2
superconductor.
25. The marine propulsion system as claimed in claim 23, wherein
the rotor, including the rotating field winding composed of HTSL
wire, includes 6 to 12 poles.
26. The marine propulsion system as claimed in claim 22, wherein
each cryostat is suppliable with coolant via a coolant circuit.
27. The marine propulsion system as claimed in claim 22, wherein
cryostats are suppliable with coolant via at least two redundant
coolant circuits.
28. The marine propulsion system as claimed in claim 26, wherein at
least one of cold helium and hydrogen gas is provided as the
coolant in the coolant circuit between a cold head and a transfer
coupling to the cryostat.
29. The marine propulsion system as claimed in claim 26, wherein
the coolant circuit between a cold head and a transfer coupling to
the cryostat is designed such that the transfer coupling is
supplied with a liquid coolant including at least one of liquid
neon, liquid hydrogen, liquid nitrogen and a liquefied gas mixture,
and vaporized coolant is fed back to the cold head.
30. The marine propulsion system as claimed in claim 28, wherein
the cold head of each coolant circuit is operatable via a
closed-cycle compressed-gas circuit.
31. The marine propulsion system as claimed in claim 30, wherein
the compressed-gas circuit for the cold head is cooled by at least
one of a central cooling water supply, sea water, and a heat
exchanging device connected to outer surfaces of the vessel over
which sea water washes.
32. The marine propulsion system as claimed in claim 28, wherein
each cold head is associated with a respective compressed-gas
circuit.
33. The marine propulsion system as claimed in claim 30, wherein
each compressed-gas circuit includes an associated integrated
sea-water cooling circuit.
34. The marine propulsion system as claimed in claim 30, wherein
each compressed-gas circuit includes an associated integrated
fresh-water circuit, with a heat exchanger to transfer heat from
the compressed-gas circuit to the integrated fresh-water
circuit.
35. The marine propulsion system as claimed in claim 34, wherein
the integrated fresh-water circuit includes another heat exchanger
to thermally connect the integrated fresh-water circuit to sea
water.
36. The marine propulsion system as claimed in claim 22, wherein
the electrical power supply includes a power machine and a
generator having a cryostat, including a rotating field winding and
is suppliable with coolant by a coolant circuit shared by the
cryostat of the electric motor and the cryostat of the electrical
power supply.
37. The marine propulsion system as claimed in claim 22, wherein
the electrical power supply includes a power machine and a
generator having a cryostat, including a rotating field winding and
is suppliable with coolant by two coolant circuits, which are
mutually redundant and are shared by cryostat of the electric motor
and the cryostat of the electrical power supply.
38. The marine propulsion system as claimed in claim 28, wherein
the cold head in each coolant circuit is arranged in the vertical
direction above that cryostat which is arranged at the highest
point in the vertical direction.
39. The marine propulsion system as claimed in claim 23, wherein
the rotor, including the rotating field winding composed of HTSL
wire, includes 8 poles.
40. The marine propulsion system as claimed in claim 27, wherein at
least one of cold helium and hydrogen gas is provided as the
coolant in the coolant circuit between a cold head and a transfer
coupling.
41. The marine propulsion system as claimed in claim 26, wherein
the coolant circuit between a cold head and a transfer coupling to
the cryostat is designed such that the transfer coupling is
supplied with a liquid coolant including at least one of liquid
neon, liquid hydrogen, liquid nitrogen and a liquefied gas mixture,
and vaporized coolant is fed back to the cold head.
42. The marine propulsion system as claimed in claim 29, wherein
the cold head of each coolant circuit is operable via a
closed-cycle compressed-gas circuit.
Description
[0001] This application is continuation of U.S. patent application
Ser. No. 10/497,171 filed on May 28, 2004, which is the national
phase under 35 U.S.C. .sctn. 371 of PCT International Application
No. PCT/DE02/04284 having an International filing date of Nov. 21,
2002, which designated the United States of America and which
claims priority on German Patent Application number DE 101 58 758.9
filed Nov. 29, 2001, the entire contents of all of which are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention generally relates to a marine or boat
propulsion system, having at least one vessel propeller.
Preferably, it includes at least one electric motor, by which the
at least one vessel propeller can be driven, and a converter-fed
electrical power supply, by which the at least one electric motor
can be supplied with electric power. It further preferably has at
least one drive machine and at least one generator which can be
driven by it. The at least one electric motor and the at least one
generator for supplying electrical power are preferably in the form
of three-phase synchronous machines.
BACKGROUND OF THE INVENTION
[0003] Diesel/electric marine propulsion systems are known, whose
power supply has synchronous generators which are accommodated at
some suitable point in the vessel's hull, and which themselves feed
converter-fed synchronous or else asynchronous motors. The electric
motors which drive the vessel propellers may, for example, be
arranged as in-board motors, and may drive the vessel propellers
via shaft systems.
[0004] Furthermore, pod propulsion systems are known, which have a
synchronous motor with permanent-magnet excitation, arranged in a
motor gondola which can be rotated. The motor gondola is arranged
outside the vessel's hull and may have one or two vessel screws.
The heat losses from the electric motor are in this case dissipated
solely by the external surface of the motor gondola to the sea
water. The asynchronous motors and generators have air/water heat
exchangers.
[0005] Furthermore, JP 63217969 and JP 04304159 disclose marine
propulsion systems for two vessel propellers including an
associated so-called "homopolar motor", which comprises two disc
rotors or cylindrical rotors through which direct current flows in
opposite directions via brushes, and in which a torque is produced
in the field of a superconducting coil.
SUMMARY OF THE INVENTION
[0006] An embodiment of the invention is based on an object of
further-developing the marine propulsion system such that it can be
designed to be at least one of more space-saving, more
weight-saving, and/or to be more efficient.
[0007] According to an embodiment of the invention, an object may
be achieved in that the at least one electric motor (which is in
the form of a three-phase synchronous machine) and/or the at least
one generator (which is in the form of a three-phase synchronous
machine) for supplying electrical power have/has a rotating field
winding composed of HTSL (high-temperature superconductor) wire.
Further, each rotating field winding composed of HTSL wire is
arranged in a cryostat, which is vacuum-insulated and can be
cryogenically cooled by means of the rotating field winding
composed of HTSL wire to a temperature between 15 and 77 K.
[0008] Without significantly changing the power levels and rotation
speed values with pod marine propulsion systems as known from the
prior art and the marine propulsion system according to an
embodiment of the invention, the ratio between the diameter of the
motor housing and the propeller external diameter in the case of
the marine propulsion system according to an embodiment of the
invention can be reduced to 30%, in comparison to 35 to 40% with
the prior art. In comparison to marine propulsion systems which are
known from the prior art and which weigh, for example, about 310 t
in total, this weight can be reduced to 100 to 200 t by using the
marine propulsion system according to an embodiment of the
invention.
[0009] Furthermore, the efficiency of the electric motor for the
marine propulsion system according to an embodiment of the
invention can be increased to 99% in comparison to 97.5% in the
case of marine propulsion systems as known from the prior art. The
considerable reductions in the physical volume and the total
weight, which amount to a factor of approximately two or more, lead
either to the usable volume in the hull of the vessel being
increased, or allow the hull of the vessel to be designed to be
smaller for the same usable volume. The machine bases may be
designed to be less complex, thus resulting in considerable
financial advantages. Since the excitation is produced without any
power consumption, the efficiency is better, and the cooling
complexity is reduced.
[0010] According to one advantageous embodiment of the marine
propulsion system according to the invention, the at least one
electric motor (which is in the form of a three-phase synchronous
machine) and/or the at least one generator (which is in the form of
a three-phase synchronous machine) for supplying electrical power
have/has an air gap three-phase winding composed of loomed copper
conductors, which is arranged in an annular gap between a rotor and
a laminated magnetic iron yoke. In the case of this stator air gap
winding, no iron teeth are provided as a source of noise, so that
the electric motors and the generators run more quietly.
[0011] The reduced weight of the rotor makes it possible to
considerably reduce the vibration that occurs. The low synchronous
reactance results in a very high short-term torque and stalling
torque. An air gap of between 5 and 50 mm, which is larger than
that with the prior art, is permissible between the rotor and the
stator. The assembly process is considerably simplified, since
wider tolerances are permissible for shaft bending, twisting due to
vessel propeller forces, etc.
[0012] It has been found to be particularly advantageous for the
HTSL wire of the rotating field winding to be formed from
multifilament ribbon conductors Bi2 Ba2 Sr2 Cu3 Ox or Bi2 Ba2 SrCu2
Ox in a silver or silver-alloy matrix, of YBa2 Cu3 Ox as a thin
film on steel strip, nickel strip, strip composed of an alloy
containing nickel, silver strip or an MgB2 superconductor.
[0013] In order to achieve electric motors of the HTSL type with
external diameters which are as small as possible, it is expedient
for the rotor (which has the rotating field winding composed of
HTSL wire) of the at least one electric motor or generator (which
is in the form of a three-phase synchronous machine) to have 6 to
12 poles, and preferably 8 poles.
[0014] According to one development of the marine propulsion system
according to an embodiment of the invention, each cryostat can be
supplied with coolant by way of a coolant circuit.
[0015] In order to improve the operational reliability of the
cooling apparatus, each cryostat can advantageously be supplied
with coolant by at least two redundant coolant circuits.
[0016] Cold helium or hydrogen gas is expediently provided as the
coolant in the coolant circuit between a cold head and a transfer
coupling to the cryostat.
[0017] Alternatively, the coolant circuit between a cold head and a
transfer coupling to the cryostat may be designed on the cryo
heatpipe principle, in which case the transfer coupling is then
supplied with liquid coolant, such as liquid neon, liquid hydrogen,
liquid nitrogen or a liquefied gas mixture, and vaporized coolant
is fed back to the cold head.
[0018] The cold head of each coolant circuit can be operated in a
simple manner by way of a closed-cycle compressed-gas circuit.
[0019] The cooling for the compressed-gas circuit for the cold head
can once again be provided by way of a central cooling water
supply, sea water, or indirectly by way of a heat exchanging
device, which is itself thermally connected to outer surfaces of
the vessel over which sea water washes.
[0020] If the marine propulsion system according to an embodiment
of the invention is in the form of a pod propulsion system, with
the at least one electric motor, which is in the form of a
three-phase synchronous machine and has the rotating field winding
composed of HTSL wire, is accommodated in a motor gondola which is
arranged outside the vessel hull. The external diameter of the at
least one electric motor may be less than 32% of the external
diameter of the vessel propeller by virtue of the high power
density which can be achieved in this way. This makes it possible
to considerably improve the hydraulic efficiency of the pod
propulsion system designed according to an embodiment of the
invention, in comparison to the prior art.
[0021] If the cold head of each coolant circuit is arranged in an
azimuth module (which can be rotated) of the pod propulsion system,
it is easily accessible, and in which case, furthermore, there is
no need for rotating couplings.
[0022] Alternatively, the cold head of each coolant circuit may be
arranged in a strut module of the pod propulsion system, in which
case it is also possible to achieve easy accessibility to the
cooling system, in a maintenance-friendly manner.
[0023] Furthermore, when appropriate requirements exist, it is
possible to arrange the cold head of each coolant circuit in the
motor gondola of the pod propulsion system close to the transfer
coupling via which coolant can be introduced into the cryostat
which holds the rotating field winding composed of HTSL wire.
[0024] A further improvement in accessibility and thus in
maintenance-friendliness of the cooling apparatus may be achieved.
This can be achieved if the compressed-gas circuit is arranged
together with the cold head on or within the azimuth module (which
can be rotated) of the pod propulsion system.
[0025] The operational reliability of the pod propulsion system
designed as described above can be increased if the cryostat of the
single electric motor which is arranged in the motor gondola of the
pod propulsion system can be supplied with coolant by use of two
coolant circuits, each of which has an associated cold head. These
two coolant circuits, which are designed as described above, are
then mutually redundant with respect to the cooling of the
cryostat.
[0026] If two co-rotating or contra-rotating (counter-rotating)
vessel propellers are provided on the motor gondola of the pod
propulsion system, each of which is associated with one of two
independent electric motors which are arranged in the motor gondola
and whose two rotors are arranged in, in each case, one cryostat,
it is advantageously possible to achieve greater redundancy for the
same volume as that for pod propulsion systems known from the prior
art, with the capability for the two vessel propellers to
contra-rotate making it possible to achieve better hydrodynamic
efficiency.
[0027] In order to improve the operational reliability of the two
electric motors which are arranged in the motor gondola, it is
advantageous for the two cryostats to be connected to in each case
one cold head via a respective coolant circuit.
[0028] The configuration of the cooling device can be simplified if
the two cryostats are connected via a respective coolant circuit to
a single cold head, which is shared by them.
[0029] Each cold head advantageously has a respective associated
compressed-gas circuit.
[0030] The compressed-gas circuit may, for example, be cooled down
by way of an integrated sea-water cooling circuit.
[0031] Alternatively, each compressed-gas circuit may be cooled
down by way of an integrated fresh-water circuit, with a gas/water
heat exchanger being provided for heat transmission from the
compressed-gas circuit to the integrated fresh-water circuit.
[0032] The heat dissipation from the integrated fresh-water circuit
can be achieved in a simple manner by this circuit having a further
heat exchanger, by which it is thermally connected to sea
water.
[0033] The transfer of the thermal energy from the integrated
fresh-water circuit into the surrounding sea water can be achieved
in a physically/technically less complex manner and nevertheless
very effectively, by arranging the further heat exchanger for the
integrated fresh-water circuit close to the wall of the strut
module of the pod propulsion system, so that it can be cooled down
by way of sea water via this wall.
[0034] Furthermore, if appropriate requirements exist, a refinement
may be advantageous in which each compressed-gas circuit is
equipped with an integrated gas/water heat exchanger, which is
itself arranged close to the wall of the strut module of the pod
propulsion system, is thermally connected to the latter, and can be
cooled via the latter by way of sea water. This allows the amount
of heat from the compressed-gas circuit to be emitted directly to
the sea water without the interposition of further circuits.
[0035] In a further advantageous embodiment of the marine
propulsion system according to an embodiment of the invention, the
cold head or heads is or are arranged in the strut module, and the
compressed-gas circuit or circuits is or are arranged in or on the
azimuth module (which can be rotated) of the pod propulsion
system.
[0036] Alternatively, the cold head or heads may be arranged in the
motor gondola of the pod propulsion system close to the transfer
coupling or couplings and the compressed-gas circuit or circuits is
or are arranged in or on the azimuth module (which can be rotated)
of the pod propulsion system.
[0037] Instead of the marine propulsion system according to an
embodiment of the invention being in the form of a pod propulsion
system, it is also possible for the at least one electric motor,
which is in the form of a three-phase synchronous machine and has
the rotating field winding composed of HTSL wire, to be
accommodated in a propeller shaft pipe on one deck of the
vessel.
[0038] Furthermore, the at least one electric motor, which is in
the form of a three-phase synchronous machine and has the rotating
field winding composed of HTSL wire, may be arranged as an in-board
motor, by which the vessel propeller associated with it is driven
via a shaft system.
[0039] The electrical power supply for the marine propulsion system
can advantageously be formed by a drive machine and a generator,
whose cryostat, which holds its rotating field winding, together
with the cryostat of the electric motor can be supplied with
coolant by use of a coolant circuit which is shared by the two
cryostats.
[0040] In order to improve the operational reliability of the
marine propulsion system, it is expedient to be possible to supply
the cryostat for the generator, together with the cryostat for the
electric motor, with coolant by way of two mutually redundant
cooling circuits which are shared by the two cryostats.
[0041] In order to provide a coolant supply by the force of gravity
in a simple manner, it is expedient for the cold head of each
coolant circuit to be arranged in the vertical direction above that
cryostat which is arranged at the highest point in the vertical
direction and is supplied from this coolant circuit.
[0042] According to a further advantageous embodiment of the
invention, each electric motor, which has its own coolant supply,
in the motor gondola of the pod propulsion system is provided with
its own electrical power supply.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] Further advantages, features and details of the invention
will become evident from the description of illustrated embodiments
given hereinbelow and the accompanying drawings, which are given by
way of illustration only and thus are not limitative of the present
invention, wherein:
[0044] FIG. 1 shows a cross-section illustration of a first
embodiment of a marine propulsion system according to the invention
in the form of a pod propulsion system;
[0045] FIG. 2 shows a longitudinal section illustration of a second
embodiment of the marine propulsion system according to the
invention in the form of a pod propulsion system;
[0046] FIG. 3 shows a longitudinal section illustration of a third
embodiment of the marine propulsion system according to the
invention in the form of a pod propulsion system;
[0047] FIG. 4 shows a longitudinal section illustration of a fourth
embodiment of the marine propulsion system according to the
invention in the form of a pod propulsion system;
[0048] FIG. 5 shows a longitudinal section illustration of a fifth
embodiment of the marine propulsion system according to the
invention in the form of a pod propulsion system;
[0049] FIG. 6 shows a longitudinal section illustration of a sixth
embodiment of the marine propulsion system according to the
invention in the form of a pod propulsion system;
[0050] FIG. 7 shows a cross-section illustration of the sixth
embodiment, as shown in FIG. 6, of the marine propulsion system
according to the invention in the form of a pod propulsion
system;
[0051] FIG. 8 shows a longitudinal section illustration of a marine
propulsion system according to the invention arranged in a
propeller shaft pipe at the stern of the ship;
[0052] FIG. 9 shows a longitudinal view of a further embodiment of
the marine propulsion system according to the invention arranged in
the propeller shaft pipe at the stern of the ship;
[0053] FIG. 10 shows a longitudinal view of a marine propulsion
system according to the invention, equipped with an in-board
motor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] A first embodiment (which is illustrated in the form of a
cross section in FIG. 1) of a marine propulsion system according to
the invention in the form of a pod propulsion system 1 has a motor
gondola 2 which is arranged underneath the hull 3 of the vessel,
and which is illustrated by dashed lines and only partially in
FIGS. 1 to 7.
[0055] Within the hull 3 of the vessel, the pod propulsion system 1
has an azimuth module 4, which is firmly connected to the motor
gondola by way of a strut module 5 through the hull 3 of the
vessel.
[0056] The pod propulsion system 1 can be rotated about a vertical
axis with respect to the hull 3 of the vessel, as can be seen from
the circular arrows 6 in FIGS. 2 to 6.
[0057] The pod propulsion system 1 as shown in FIG. 1 has an
electric motor 7 arranged within the motor gondola 2. A vessel
propeller 8, which is arranged at the rear end of the motor gondola
2 such that it can rotate, is driven by means of this electric
motor 7.
[0058] For this purpose, the electric motor 7 (which is in the form
of a three-phase synchronous machine) has an 8-pole rotor 9, which
is equipped with a rotating field winding 10 composed of HTSL
(high-temperature superconductor) wire.
[0059] This HTSL wire may be formed from multifilament ribbon
conductors Bi2 Ba2 Sr2 Cu3 Ox or Bi2 Ba2 Sr Cu2 Ox in a silver or
silver-alloy matrix, of YBa2 Cu3 Ox as a thin film on steel strip,
nickel strip, silver strip or an MgB2 superconductor.
[0060] The electric motor 7 (which is in the form of a three-phase
synchronous machine) furthermore has an air gap three-phase or
stator winding 11 composed of loomed copper conductors, which is
arranged in an annular gap 12 between the 8-pole rotor 9 (which is
equipped with the rotating field winding 10 composed of HTSL wire)
and a laminated magnetic iron yoke 13.
[0061] The 8-pole rotor 9 which has the rotating field winding 10
composed of HTSL wire is held within a cryostat 14, which is
designed to be vacuum-insulated and can be cryogenically cooled by
means of the rotating field winding 10 composed of HTSL wire to a
temperature between 15 and 77 K.
[0062] The cryostat 14 is included in a coolant circuit 16 via a
transfer coupling 15 which is arranged coaxially with respect to
the longitudinal center axis of the 8-pole rotor 9. A cold head 17
is integrated in the coolant circuit 16 and is cooled on the basis
of the Gifford-MacMahon, Stirling or Pulsetube principle by means
of a compressed-gas circuit 18, which includes a compressor 19 and
a gas/water heat exchanger or cooler 20.
[0063] The coolant circuit 16, which is provided by the cold head
17 on the one hand and the rotor-side or cryostat-side transfer
coupling 15 on the other hand, may carry cold helium or hydrogen
gas as the coolant. Furthermore, the coolant circuit 16 may be
designed on the cryo heatpipe principle, in which case it is then
supplied as the liquid coolant with liquid neon, liquid hydrogen,
liquid nitrogen or a liquefied gas mixture to the cryostat 14 and
to the transfer coupling 15, and feeds back vaporized neon,
vaporized hydrogen, vaporized nitrogen or a vaporized gas mixture
from the cryostat 14 and from the transfer coupling 15 to the cold
head 17.
[0064] The compressed-gas circuit 18 including the cold head 17 is,
in the exemplary embodiment illustrated in FIG. 1, accommodated in
an easily accessible manner on or within the azimuth module 4
(which can be rotated) of the pod propulsion system 1, so that
there is no need for rotary couplings.
[0065] An embodiment of the pod propulsion system 1, shown in the
form of a longitudinal section in FIG. 2, has two mutually
independent electric motors 21, 22, by which two vessel propellers
23, 24 are driven, which are mounted such that they can rotate at
the front end and rear end of the motor gondola 2. The vessel
propellers 23, 24 may be oriented such that they contra-rotate.
FIG. 2 also shows the two three-phase supply lines 25, 26 for the
two electric motors 21, 22. Each electric motor 21, 22 has a
separate cryostat 27, 28. Each cryostat 27, 28 is connected via
transfer couplings 15 to a coolant circuit 29, 30, with a
respective cold head 31 or 32 being arranged in the respective
coolant circuit 29 or 30. Each respective cold head 31 or 32 is in
turn associated with a respective compressed-gas circuit 33 or
34.
[0066] The two compressed-gas circuits 33, 34 are arranged in the
azimuth 111 module 4, and the two cold heads 31, 32 are arranged in
the strut module 5 of the pod propulsion system 1, so that they are
easily accessible and are maintenance-friendly. The provision of
two electric motors 21, 22 whose 8-pole rotors 9 are supplied with
coolant independently of one another results in better availability
of the pod propulsion system 1 in comparison to the embodiment
shown in FIG. 1.
[0067] The availability can be increased if the electrical power
supply for each electric motor 21, 22 is provided individually via
respectively separate sliprings or converters. FIG. 2 shows only a
single converter supply, which supplies both electric motors 21, 22
at the same time.
[0068] FIG. 3 shows a modified form of the pod propulsion system 1
as shown in FIG. 2, in the form of a longitudinal section, in which
the cryostats 27, 28 of the two electric motors 21, 22 are supplied
with coolant by way of the two coolant circuits 29, 30. The two
coolant circuits 29, 30 are however, in contrast to FIG. 2,
connected to a cold head 35 which is shared by them and is arranged
close to the two transfer couplings 15 of the cryostats 27, 29 in
the motor gondola 2 of the pod propulsion system 1.
[0069] The cold head 35 is itself cooled by a compressed-gas
circuit 36, whose major components are arranged in or fitted to the
azimuth module 4 of the pod propulsion system 1.
[0070] The compressed-gas circuit 36 is cooled by use of an
integrated sea-water cooling circuit 37, which extracts thermal
energy from the compressed-gas circuit 36 via a heat exchanger unit
38. The major components of the integrated sea-water cooling
circuit 37 are also arranged in or on the azimuth module 4 of the
pod propulsion system 1.
[0071] The components which are provided for supplying coolant
circuits 29, 30 which are associated with the cryostats 27, 28 may
also be designed in redundant or duplicated form in order to
improve the operational reliability, as shown in the embodiment in
FIG. 3.
[0072] In the case of the embodiment of the pod propulsion system 1
shown in FIG. 4, the cold head 35 is also arranged in the motor
gondola 2, close to the transfer couplings 15 which are arranged
coaxially with respect to the rotor axis 39 of the rotors 9 of the
two electric motors 21, 22. The compressed-gas circuit 36, which is
associated with the cold head 35, is cooled down by means of a
gas/water heat exchanger 40, which is arranged in the
compressed-gas circuit 36 and is also a component of an integrated
fresh-water circuit 41.
[0073] The integrated fresh-water circuit 41 is cooled by way of a
further heat exchanger 42, which is thermally connected to the wall
43 of the strut module 5 of the pod propulsion system 1. The
further heat exchanger 42 in the integrated fresh-water circuit 41
is thus cooled down by use of sea water through the wall 43 of the
strut module 5 of the pod propulsion system 1.
[0074] The major components both of the compressed-gas circuit 36
and of the integrated fresh-water circuit 41 are arranged in a
maintenance-friendly manner in the azimuth module 4 of the pod
propulsion system 1, while in contrast the cold head 35 is, as
already mentioned above, seated in the motor gondola 2 of the pod
propulsion system 1.
[0075] Alternatively, two cold heads 35 may be provided, each of
which is associated with a respective one of the two electric
motors 21, 22, and both of which may be cooled down by way of the
compressed-gas circuit 36.
[0076] The pod propulsion system 1 which is shown in FIG. 5 has an
electric motor 7 which drives the single vessel propeller 8 of the
pod propulsion system 1, and occupies virtually the entire interior
(whose diameter is constant) of the motor gondola 2 of the pod
propulsion system 1. In comparison to the pod propulsion systems
equipped with two electric motors as shown in FIGS. 2 to 4, in the
case of the embodiment shown in FIG. 5, the length of the motor
gondola 2 is made better use of for installation of a higher motor
power.
[0077] The cryostat 14 of the electric motor 7 is connected by way
of the transfer coupling 15 to two coolant circuits 44, 45, which
are based on the cryo heatpipe principle, and which have a
respectively associated cold head 46 and 47. The two cold heads 46,
47 are arranged in the azimuth module 4 of the pod propulsion
system, and are cooled down by way of compressed-gas circuits 33,
34, which are likewise provided in the azimuth module 4 of the pod
propulsion system 1. The redundancy which is provided by the
duplicated form of the components which are provided for cooling of
the electric motor 7 improves the operational reliability of the
pod propulsion system 1.
[0078] In embodiments of the pod propulsion system 1, illustrated
as longitudinal sections and cross sections respectively in FIGS. 6
and 7, the cryostat 14 of the single electric motor 7 which is
arranged in the motor gondola 2 is supplied with coolant from a
coolant circuit 16 by the transfer coupling 15. The cold head 17,
which is associated with the coolant circuit 16, is arranged in the
strut module 5 in the case of the embodiment shown in FIG. 6, and
is arranged in the azimuth module 4 of the pod propulsion system 1
in the case of the embodiment shown in FIG. 7. In both embodiments,
the cold head 17 is cooled down by means of a compressed-gas
circuit 18, with an integrated gas/water heat exchanger 48 being
used to extract heat from this compressed-gas circuit 18. This
gas/water heat exchanger 48 is arranged on the wall 43 of the strut
module 5, as can be seen in particular in FIG. 7.
[0079] This gas/water heat exchanger 48 is thermally connected in a
corresponding manner to the wall 43 of the strut module 5, and thus
to the sea water surrounding the strut module 5. In the embodiments
shown in FIG. 6 and FIG. 7, the compressed-gas circuit is cooled
down directly by the sea water, in which case the heat exchanger
pipe runs 49 in the gas/water heat exchanger 48 can be arranged
directly against the wall 43 of the strut module 5.
[0080] In the embodiments shown in FIGS. 8 and 9, an electric motor
7 for the marine propulsion system is arranged fixed in a propeller
shaft pipe 51, which is formed at the stern 50 of the vessel. The
cryostat 14 of the electric motor 7 is connected by way of the
transfer coupling 15 to two coolant circuits 44, 45, which have a
respective cold head 46, 47. The two cold heads 46, 47 are
respectively cooled down by a compressed-gas circuit 33, 34. The
cooling of the cryostat 14 of the electric motor 7 is thus
redundant.
[0081] In addition to the electric motor 7 for the marine
propulsion system, FIG. 9 also shows a power generating system with
a generator 52, which is driven by a drive machine in the form of
an internal combustion engine 53.
[0082] The generator 52 has a rotor, which is not illustrated in
detail in the figures, with a rotating field winding composed of
HTSL wire, with the cryostat for the generator 52 being supplied
with coolant in a redundant manner both by the coolant circuit 44
and by the coolant circuit 45, as can be seen in FIG. 9.
Alternatively, it is possible to supply the generator 52 and the
electric motor 7 by way of a single coolant circuit and the
associated system parts.
[0083] The cold heads 46, 47 which are shown in FIG. 9 are arranged
on a higher deck than the load that is arranged at the highest
point, so that the coolant can be supplied by the force of gravity
via the coolant circuits 44, 45, which are designed on the basis of
the cryo heatpipe principle.
[0084] Alternatively, the coolant circuits 44, 45 may also be in
the form of separate liquid and cold-gas lines.
[0085] In the embodiment of the marine propulsion system according
to the invention as illustrated in FIG. 10, the electric motor 7 is
in the form of an in-board motor, on the output side driving a
shaft system 54, which itself rotates the vessel propeller 8.
[0086] An internal combustion engine 53 is provided as the drive
machine for the marine propulsion system, drives the generator 52,
and may be in the form of a diesel engine, a gas turbine or a steam
turbine.
[0087] The generator 52 and the electric motor 7 each have a rotor
with a rotating field winding composed of HTSL wire. The two
cryostats of the generator 52 and of the electric motor 7 are
supplied with coolant by way of a coolant circuit 16, with the cold
head 17 in the coolant circuit 16 being cooled down by way of the
compressed-gas circuit 18. The cold head 17 is arranged above the
highest coolant load, so that--as in the case of the embodiment
shown in FIG. 9--the coolant can be supplied by the force of
gravity.
[0088] According to one exemplary embodiment of a pod propulsion
system, a drive stage (equipped with two electric motors of the
HTSL type) for a pod propulsion system 1 has a rating of 20 MW at
130 rpm. The available rotation speed range is between 70 and 160
rpm. The external diameter of the vessel propeller is 6250 mm. The
external diameter of the motor housing and of the motor gondola of
the pod propulsion system is 30% of the external diameter of the
vessel propeller. The overall length of the pod propulsion system
is approximately 11 000 mm. The vessel propeller torque is
approximately 1480 kNm. The weight of the entire system is
approximately 100 to 200 t, with the efficiency of the motor stage
being approximately 99%.
[0089] Exemplary embodiments being thus described, it will be
obvious that the same may be varied in many ways. Such variations
are not to be regarded as a departure from the spirit and scope of
the present invention, and all such modifications as would be
obvious to one skilled in the art are intended to be included
within the scope of the following claims.
* * * * *