U.S. patent application number 13/381144 was filed with the patent office on 2012-05-03 for gas-fired superconductive electrically propelled ship.
This patent application is currently assigned to IHI MARINE UNITED INC.. Invention is credited to Takayuki Kida, Tomoaki Takahira.
Application Number | 20120108116 13/381144 |
Document ID | / |
Family ID | 43428987 |
Filed Date | 2012-05-03 |
United States Patent
Application |
20120108116 |
Kind Code |
A1 |
Takahira; Tomoaki ; et
al. |
May 3, 2012 |
GAS-FIRED SUPERCONDUCTIVE ELECTRICALLY PROPELLED SHIP
Abstract
A gas-fired superconductive electrically propelled ship is
provided with a cargo tank 1 (fuel tank) for storage of LNG 2, a
vaporized gas feed line 3 for feeding of vaporized gas 2' produced
in the cargo tank 1 as fuel to dual-fuel engines (driving engines)
5 for generators 6, a gas heater 4 incorporated in the vaporized
gas feed line 3 for heating of the vaporized gas 2', a propelling
superconductive motor 7 driven with electric power produced by the
generator 6, a heat pump 15 for cooling the superconductive motor 7
and maintaining low temperature of the motor and an LNG
gasification line 26 for feeding of LNG 2 from the cargo tank 1 as
cold source for compression radiation treatment in the heat pump 15
and for guiding of the vaporized gas 2' having treated to the cargo
tank 1 and to the vaporized gas feed line 3 at entry-side of the
gas heater 4.
Inventors: |
Takahira; Tomoaki; (Tokyo,
JP) ; Kida; Takayuki; (Tokyo, JP) |
Assignee: |
IHI MARINE UNITED INC.
Tokyo
JP
|
Family ID: |
43428987 |
Appl. No.: |
13/381144 |
Filed: |
June 22, 2010 |
PCT Filed: |
June 22, 2010 |
PCT NO: |
PCT/JP2010/004135 |
371 Date: |
December 28, 2011 |
Current U.S.
Class: |
440/6 |
Current CPC
Class: |
B63J 2/12 20130101; Y02T
70/5236 20130101; Y02T 10/36 20130101; F02D 19/0665 20130101; Y02T
10/32 20130101; B63H 2021/173 20130101; Y02T 10/30 20130101; Y02T
70/5263 20130101; F01K 15/04 20130101; Y02T 70/72 20130101; F02D
19/0647 20130101; F02M 21/06 20130101; Y02T 70/50 20130101; Y02T
70/5218 20130101; B63H 2021/205 20130101; Y02T 70/00 20130101; B63J
2099/003 20130101; B63H 21/17 20130101; B63H 21/38 20130101 |
Class at
Publication: |
440/6 |
International
Class: |
B63H 21/17 20060101
B63H021/17; B63H 21/38 20060101 B63H021/38; F01K 25/10 20060101
F01K025/10; B63B 25/12 20060101 B63B025/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 6, 2009 |
JP |
2009-159649 |
Claims
1. A gas-fired superconductive electrically propelled ship
comprising a fuel tank for storing LNG, a vaporized gas feed line
for feeding as fuel of vaporized gas generated in said fuel tank to
driving engines for generators, a gas heater incorporated in said
vaporized gas feed line for heating the vaporized gas, a propelling
superconductive motor driven with electric power generated by said
generators, a heat pump for cooling said superconductive motor and
maintaining low temperature thereof and an LNG gasification line
for feeding of LNG from the fuel tank as cold source in compression
radiation treatment in said heat pump and for guiding of the
vaporized gas having treated to the fuel tank and to entry-side of
the gas heater in said vaporized gas feed line.
2. The gas-fired superconductive electrically propelled ship as
claimed in claim 1, wherein the LNG gasification line has cooling
lines in parallel with one another and passing respectively through
various devices and equipments in the ship.
3. The gas-fired superconductive electrically propelled ship as
claimed in claim 1, wherein the fuel tank is a cargo tank.
4. The gas-fired superconductive electrically propelled ship as
claimed in claim 2, wherein the fuel tank is a cargo tank.
Description
TECHNICAL FIELD
[0001] The present invention relates to a gas-fired superconductive
electrically propelled ship.
BACKGROUND ART
[0002] Nowadays, as an LNG ship for transporting LNG (liquid
natural gas), a gas-fired electrically propelled ship is in service
in which boil-off gas from LNG as cargo is utilized as fuel for
diesel generators to drive an electric motor by resultant electric
power for propulsion. In order to attain a further high-efficiency
electric propulsion system, researches have been made on
development of a gas-fired superconductive electrically propelled
ship using a superconductive motor.
[0003] FIG. 1 shows an example of a conventionally proposed
gas-fired superconductive electrically propelled ship comprising
existent systems in combination. In FIG. 1, reference numeral 1
denotes a cargo tank 1 for storage of cargo which is LNG 2
(especially, a separate tank for fuel may be installed). Vaporized
gas (boil-off gas) 2' generated in the cargo tank 1 is fed to
dual-fuel engines 5 through a vaporized gas feed line 3 after
heated by a gas heater 4; and the gas is used in the engines 5 as
fuel to drive generators 6, resultant electric power being supplied
to a propelling superconductive motor 7.
[0004] Furthermore, where necessary, part of the liquid phase LNG 2
stored in the cargo tank 1 may be pumped from a bottom of the tank
through an LNG gasification line 9 with a pump 8 and vaporized
through a vaporizer 10, resultant vaporized gas 2' being also fed
as fuel to the engines 5 through joining to the vaporized gas feed
line 3 at exit-side of the gas heater 4.
[0005] To the gas heater 4 and vaporizer 10, for example, vapor 11
from a boiler equipments or the like in the ship may be introduced
and utilized as heat source. For example, at start-up where heat
source is difficult to secure, heavy oil 13 from a heavy oil tank
12 may be appropriately guided as fuel to the engines 5.
[0006] On the other hand, the superconductive motor 7 is cooled to
about -196.degree. C. by a heat pump 15 with helium as cooling
medium 14. Specifically, the cooling medium 14 which is helium gas
highly temperatured and highly pressured through compression by a
compressor 16 is guided to a condenser 17 where it is cooled into
helium liquid with medium temperature and high pressure through
heat-exchange with clear water 19 from a clear-water central
cooling system 18 referred to hereinafter. The helium liquid is
expanded and vaporized by an expansion valve 20 just in front of
the superconductive motor 7. Thus, cooling to a conditional
temperature for superconductivity is managed through evaporative
cooling of field and armature coils in the motor 7. The helium gas
discharged from the superconductive motor 7 is returned to the
compressor 16 for circulation.
[0007] In the example illustrated, clear water 19 from the
clear-water central cooling system 18 is used as a cold source for
the compression radiation treatment in the condenser 17 of the heat
pump 15. The clear-water central cooling system 18 serves to cool
various devices and equipments 21 in the ship by means of the clear
water 19 circulated in a closed circuit 22. The clear water 19
having been warmed by its passing through the condenser 17 of the
heat pump 15 and the devices and equipments 21 is cooled through
heat exchange with seawater 24 from outboard in a clear water
cooler 23 incorporated in the closed circuit 22.
[0008] As prior art literatures pertinent to the invention, there
already exists, for example, the following Patent Literatures 1 and
2.
CITATION LIST
Patent Literature
[0009] [Patent Literature 1] JP2005-186815A [0010] [Patent
Literature 2] JP2005-183440A
SUMMARY OF INVENTION
Technical Problems
[0011] However, in the conventionally proposed gas-fired
superconductive electrically propelled ship comprising the existing
systems in combination as shown in FIG. 1, heat obtained during the
cooling process of the superconductive motor 7 is vainly discharged
to the sea through heat exchange with the seawater. Moreover, heat
for heating of the vaporized gas (boil-off gas) 2' generated in the
cargo tank 1 by the gas heater 4 and for vaporization in the
vaporizer 10 of the liquid phase LNG 2 taken out from the cargo
tank 1 has to be secured by inboard facilities, disadvantageously
resulting in deterioration of systems energy efficiency.
Furthermore, a cooling system for the superconductive motor 7 and a
heating system for vaporization of the LNG 2 are separately
required, disadvantageously resulting in complex systems
configuration and thus increase in installation cost.
[0012] The invention was made in view of the above and has its
object to provide a gas-fired superconductive electrically
propelled ship which has satisfactory systems energy efficiency and
is inexpensive in installation cost.
Solution to Problems
[0013] The invention is directed to a gas-fired superconductive
electrically propelled ship comprising a fuel tank for storing LNG,
a vaporized gas feed line for feeding as fuel of vaporized gas
generated in said fuel tank to driving engines for generators, a
gas heater incorporated in said vaporized gas feed line for heating
the vaporized gas, a propelling superconductive motor driven with
electric power generated by said generators, a heat pump for
cooling said superconductive motor and maintaining low temperature
thereof and an LNG gasification line for feeding of LNG from the
fuel tank as cold source in compression radiation treatment in said
heat pump and for guiding of the vaporized gas having treated to
the fuel tank and to entry-side of the gas heater in said vaporized
gas feed line.
[0014] Thus, in this way, LNG is fed from the fuel tank through the
LNG gasification line to the heat pump and is utilized as cold
source in compression radiation treatment in the heat pump, thus
contributing to cooling of the superconductive motor. On the other
hand, LNG itself is guided as vaporized gas to the fuel tank and to
entry-side of the gas heater in the vaporized gas feed line, is
heated by the gas heater together with the vaporized gas generated
in the fuel tank and then is fed to the driving engines where it is
used as fuel for generation of electric power by the generators,
resultant electric power being supplied to a propelling
superconductive motor for driving of the motor.
[0015] Further, in the invention, it is preferable that LNG
gasification line has cooling lines in parallel with one another
and passing respectively through various devices and equipments in
the ship, which makes it possible to utilize exhaust heat from the
devices and equipments effectively for gasification of LNG and
which makes it possible to omit a part or all of the clear-water
central cooling system to further reduce the installation cost.
[0016] Further, in the invention, the fuel tank may be a cargo
tank, which makes it possible to utilize LNG as cargo as fuel of
the driving engines for the generators. As a result, there is no
need of providing a fuel tank separately from the cargo tank,
leading to further reduction in installation cost.
Advantageous Effects of Invention
[0017] According to the above-mentioned gas-fired superconductive
electrically propelled ship of the invention, the flowing various
excellent effects and advantages can be obtained.
[0018] (I) LNG in the fuel tank is utilized as cold source for
cooling of the superconductive motor before it is fed as fuel to
the driving engines for the generators, heat obtained during the
cooling process of the superconductive motor being utilized for
vaporization of LNG. As a result, systems energy efficiency can be
substantially enhanced. Moreover, a system of cooling the
superconductive motor and a system of vaporizing LNG are integrated
into a single system, so that systems configuration can be
simplified to substantially reduce the installation cost.
[0019] (II) When the LNG gasification line has the cooling lines in
parallel with one another and passing respectively through the
various devices and equipments in the ship, the exhaust heat from
the devices and equipments can be effectively utilized for
gasification of LNG and a part or all of the clear-water central
cooling system can be omitted to further reduce the installation
cost.
[0020] (III) When the fuel tank is a cargo tank, LNG as cargo can
be used as fuel for the driving engines for the generators. A fuel
tank may not be provided separately from the cargo tank, leading to
further reduction in installation cost.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a systematic diagram showing a conventional
example; and
[0022] FIG. 2 is a systematic diagram showing an embodiment of the
invention.
DESCRIPTION OF EMBODIMENT
[0023] An embodiment of the invention will be described in
conjunction with the drawings.
[0024] FIG. 2 is an embodiment of the invention in which parts
similar to those in FIG. 1 are represented by the same reference
numerals.
[0025] In the embodiment, in place of the clear water 19 (see FIG.
1) from the clear-water central cooling system (see FIG. 1) which
is used as cold source in the compression radiation treatment in
the condenser 17 of the heat pump 15 in the previous FIG. 1, an LNG
gasification line 26 is newly provided which is for feed of LNG 2
from the cargo tank 1 (fuel tank) through a pump 25 as cold source
for the compression radiation treatment in the condenser 17 of the
heat pump 15, and the vaporized gas 2' having treated is guided to
the cargo tank 1 and to entry-side of the gas heater 4 in the
vaporized gas feed line 3 while the LNG gasification line 9 (see
FIG. 1) employed in the systematic configuration in FIG. 1 for
joining LNG 2 in the cargo tank 1 as the vaporized gas 2' through
the vaporizer 10 (see FIG. 1) to exit-side of the gas heater 4 in
the vaporized gas feed line 3 is abolished.
[0026] Further, specifically in the embodiment, the LNG
gasification line 26 has cooling lines 27 which are in parallel
with one another and pass respectively through various devices and
equipments 21 in the ship, LNG 2 passing through the respective
cooling lines 27 cooling the devices and equipments 21. Such
cooling of the devices and equipments 21 also facilitates
vaporization of LNG 2.
[0027] In the gas-fired superconductive electrically propelled ship
thus constructed, LNG 2 is fed from the cargo tank 1 through the
LNG gasification line 26 to the heat pump 15 and is utilized as
cold source for the compression radiation treatment in the heat
pump 15, thus contributing to cooling of the superconductive motor
7. On the other hand, LNG 2 itself is guided as vaporized gas 2' to
the cargo tank 1 and to entry-side of the gas heater 3 in the
vaporized gas feed line 3, is heated by the gas heater 4 together
with the vaporized gas 2' generated in the cargo tank 1 and then is
fed to the dual-fuel engines (driving engines for the generators 6)
where it is used as fuel for generation of electric power by the
generator 6, resultant electric power being supplied to a
propelling superconductive motor 7 for driving of the motor 7.
[0028] Incidentally, the vaporized gas 2' guided through the LNG
gasification line 26 to the entry-side of the gas heater 4 in the
vaporized gas feed line 3 has relatively elevated temperature due
to the heat obtained during the cooling process of the
superconductive motor 7, so that a required amount of heat source
to be charged for heat exchange in the gas heater 4 is less than
that required as in the case of FIG. 1 for temperature elevation of
only the vaporized gas (boil-off gas) 2' generated in the cargo
tank 1.
[0029] According to the gas-fired superconductive electrically
propelled ship as mentioned in the above, LNG 2 in the cargo tank 1
is utilized as cold source for cooling of the superconductive motor
7 before it is fed as fuel to the dual-fuel engines 5 for the
generators 6, the heat obtained during the cooling process of the
superconductive motor 7 being utilized for vaporization of LNG 2.
As a result, systems energy efficiency can be substantially
enhanced. Moreover, a system of cooling the superconductive motor 7
and a system of vaporizing LNG 2 are integrated into a single
system, so that systems configuration can be simplified to
substantially reduce the installation cost.
[0030] Moreover, especially in the embodiment, the LNG gasification
line 26 has cooling lines 27 in parallel with one another and
passing respectively through the various devices and equipments 21
in the ship, so that exhaust heat from the devices and equipments
21 can be effectively utilized for gasification of LNG 2 and a part
or all of the clear-water central cooling system can be omitted to
further reduce the installation cost.
[0031] Further, in the embodiment, the cargo tank 1 for storage of
LNG 2 as cargo is the fuel tank, so that LNG 2 as cargo can be
utilized as fuel for the dual-fuel engines 5 for the generators 6,
which makes it unwanted to provide a fuel tank separately from the
cargo tank 1, leading to further reduction in installation
cost.
[0032] It is to be understood that a gas-fired superconductive
electrically propelled ship of the invention is not limited to the
above embodiment and that various changes and modifications may be
made without departing from the scope of the invention. For
example, though the embodiment illustrated exemplifies a case where
the fuel tank is the cargo tank, the fuel tank may be installed
separately from the cargo tank. The cooling medium for the heat
pump is not necessarily restricted to helium.
REFERENCE SIGNS LIST
[0033] 1 cargo tank (fuel tank) [0034] 2 LNG [0035] 2' vaporized
gas [0036] 3 vaporized gas feed line [0037] 4 gas heater [0038] 5
dual-fuel engine (driving engine) [0039] 6 generator [0040] 7
superconductive motor [0041] 15 heat pump [0042] 21 various devices
and equipments [0043] 26 LNG gasification line [0044] 27 cooling
line
* * * * *