U.S. patent application number 13/551568 was filed with the patent office on 2014-01-23 for system and method for using a chilled fluid to cool an electromechanical machine.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is William Hunter Boardman, IV, Richard Anthony DePuy, James Michael Fogarty, Rebecca Ann Nold. Invention is credited to William Hunter Boardman, IV, Richard Anthony DePuy, James Michael Fogarty, Rebecca Ann Nold.
Application Number | 20140020426 13/551568 |
Document ID | / |
Family ID | 49945415 |
Filed Date | 2014-01-23 |
United States Patent
Application |
20140020426 |
Kind Code |
A1 |
Nold; Rebecca Ann ; et
al. |
January 23, 2014 |
SYSTEM AND METHOD FOR USING A CHILLED FLUID TO COOL AN
ELECTROMECHANICAL MACHINE
Abstract
A system includes an air separation unit configured to generate
a chilled fluid. The system also includes an electromechanical
machine configured to be cooled via heat exchange with the chilled
fluid.
Inventors: |
Nold; Rebecca Ann;
(Glenville, NY) ; Fogarty; James Michael;
(Schenectady, NY) ; DePuy; Richard Anthony; (Burnt
Hills, NY) ; Boardman, IV; William Hunter; (Burnt
Hills, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nold; Rebecca Ann
Fogarty; James Michael
DePuy; Richard Anthony
Boardman, IV; William Hunter |
Glenville
Schenectady
Burnt Hills
Burnt Hills |
NY
NY
NY
NY |
US
US
US
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
49945415 |
Appl. No.: |
13/551568 |
Filed: |
July 17, 2012 |
Current U.S.
Class: |
62/640 |
Current CPC
Class: |
F25J 3/04527 20130101;
Y02E 20/16 20130101; F25J 2240/70 20130101; Y02E 20/18 20130101;
F25J 2260/58 20130101; Y02P 80/156 20151101; F25J 3/04563 20130101;
F25J 3/04612 20130101; F25J 2260/44 20130101; F25J 3/04575
20130101; F25J 3/04545 20130101; F25J 2240/82 20130101 |
Class at
Publication: |
62/640 |
International
Class: |
F25J 3/08 20060101
F25J003/08 |
Claims
1. A system, comprising: an air separation unit configured to
generate a chilled fluid; and an electromechanical machine, wherein
the electromechanical machine is configured to be cooled via heat
exchange with the chilled fluid.
2. The system of claim 1, wherein the air separation unit is
configured to generate nitrogen as the chilled fluid.
3. The system of claim 1, comprising an integrated gasification
combined cycle (IGCC) power plant comprising the air separation
unit and the electromechanical machine.
4. The system of claim 1, wherein the electromechanical machine
comprises a generator, wherein the generator comprises a rotor and
a stator.
5. The system of claim 4, wherein the rotor and the stator are
configured to be cooled via heat exchange with the chilled
fluid.
6. The system of claim 1, comprising a heat exchanger configured to
receive the chilled fluid, cool a heat transfer fluid via heat
exchange with the chilled fluid, and circulate the heat transfer
fluid through the electromechanical machine.
7. The system of claim 6, wherein the heat exchanger is disposed in
the air separation unit, or the electromechanical machine, or any
combination thereof
8. The system of claim 1, wherein the air separation unit comprises
a chilled fluid reservoir configured to store the chilled
fluid.
9. The system of claim 1, comprising a controller configured to
maintain a temperature of the electromechanical machine below a
threshold temperature.
10. A system, comprising: a electromechanical machine temperature
controller configured to control a heat exchange system to maintain
a temperature of an electromechanical machine below a threshold
temperature, wherein the heat exchange system comprises a chilled
fluid circuit configured to remove heat from the electromechanical
machine via heat exchange with a heat transfer fluid and a chilled
fluid, and the chilled fluid is generated by an air separation unit
fluidly coupled to the heat exchange system.
11. The system of claim 10, comprising the electromechanical
machine, wherein the electromechanical machine comprises a
generator, the generator comprises a rotor and a stator, and the
electromechanical machine temperature controller is configured to
control the heat exchange system to remove heat from the rotor and
the stator via heat exchange.
12. The system of claim 10, comprising the air separation unit,
wherein the air separation unit comprises a heat exchanger and the
electromechanical machine temperature controller is configured to
control a first flow of the chilled fluid and a second flow of the
heat transfer fluid through the heat exchanger.
13. The system of claim 10, comprising an integrated gasification
combined cycle (IGCC) power plant comprising the air separation
unit, the electromechanical machine, and the heat exchange
system.
14. The system of claim 10, comprising a gas turbine, wherein the
electromechanical machine controller is configured to direct a
first flow of the chilled fluid into the gas turbine as a
diluent.
15. A method, comprising: generating a chilled fluid using an air
separation unit; removing heat from an electromechanical machine
via heat exchange with the chilled fluid; and controlling the heat
exchange to maintain a temperature of the electromechanical machine
below a threshold temperature.
16. The method of claim 15, wherein removing heat comprises cooling
a heat transfer fluid configured to exchange heat with the chilled
fluid and the electromechanical machine.
17. The method of claim 16, wherein the electromechanical machine
comprises a generator, wherein the generator comprises a rotor and
a stator, and controlling the heat exchange comprises directing the
heat transfer fluid to come in contact with the rotor, the stator,
or both.
18. The method of claim 15, comprising circulating the chilled
fluid through a heat exchange system.
19. The method of claim 15, comprising using the chilled fluid as a
diluent in a gas turbine.
20. The method of claim 15, comprising moderating a temperature of
the chilled fluid with a gas, wherein the gas is warmer than the
chilled fluid.
Description
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to relates to
industrial plants, and more specifically, to systems and methods to
use a chilled fluid of the industrial plant to cool a portion of
the industrial plant.
[0002] In general, an integrated gasification combined cycle (IGCC)
power plant converts a fuel source into syngas through the use of a
gasifier. A typical IGCC gasifier may combine a fuel source (e.g.,
a coal slurry) with steam and oxygen to produce the syngas. The
product syngas may be provided to a combustor to combust the syngas
with oxygen in order to drive one or more gas turbines. Heat from
the IGCC power plant may also be used to drive one or more steam
turbines. The one or more turbines may drive generators to produce
electricity. A generator may warm due to electrical losses such as
resistive heating from electrical current flowing through coils or
due to other heat sources within the generator or IGCC power plant.
High generator temperatures may decrease the operational life of
the generator and limit the output or efficiency of the
generator.
BRIEF DESCRIPTION OF THE INVENTION
[0003] Certain embodiments commensurate in scope with the
originally claimed invention are summarized below. These
embodiments are not intended to limit the scope of the claimed
invention, but rather these embodiments are intended only to
provide a brief summary of possible forms of the invention. Indeed,
the invention may encompass a variety of forms that may be similar
to or different from the embodiments set forth below.
[0004] In a first embodiment, a system includes an air separation
unit configured to generate a chilled fluid. The system also
includes an electromechanical machine configured to be cooled via
heat exchange with the chilled fluid.
[0005] In a second embodiment, a system includes an
electromechanical machine temperature controller configured to
control a heat exchange system to maintain a temperature of an
electromechanical machine below a threshold temperature. The heat
exchange system includes a chilled fluid circuit configured to
remove heat from the electromechanical machine via heat exchange
with a heat transfer fluid and a chilled fluid. The chilled fluid
is generated by an air separation unit fluidly coupled to the heat
exchange system.
[0006] In a third embodiment, a method includes generating a
chilled fluid using an air separation unit, removing heat from an
electromechanical machine via heat exchange with the chilled fluid,
and controlling the heat exchange to maintain a temperature of the
electromechanical machine below a threshold temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features, aspects, and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0008] FIG. 1 illustrates a block diagram of an embodiment of an
integrated gasification combined cycle (IGCC) power plant having a
chilled fluid cooling conduit;
[0009] FIG. 2 illustrates a block diagram of an embodiment of the
chilled fluid cooling conduit having a heat exchanger coupled to a
chilled fluid system and a generator;
[0010] FIG. 3 illustrates a block diagram of an embodiment of the
chilled fluid cooling conduit having a cooler coupled to a chilled
fluid system and a component of the generator; and
[0011] FIG. 4 illustrates a block diagram of an embodiment of the
chilled fluid system coupled to a gas turbine engine.
DETAILED DESCRIPTION OF THE INVENTION
[0012] One or more specific embodiments of the present invention
will be described below. In an effort to provide a concise
description of these embodiments, all features of an actual
implementation may not be described in the specification. It should
be appreciated that in the development of any such actual
implementation, as in any engineering or design project, numerous
implementation-specific decisions must be made to achieve the
developers' specific goals, such as compliance with system-related
and business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that
such a development effort might be complex and time consuming, but
would nevertheless be a routine undertaking of design, fabrication,
and manufacture for those of ordinary skill having the benefit of
this disclosure.
[0013] When introducing elements of various embodiments of the
present invention, the articles "a," "an," "the," and "said" are
intended to mean that there are one or more of the elements. The
terms "comprising," "including," and "having" are intended to be
inclusive and mean that there may be additional elements other than
the listed elements. The term "cryogenic" is intended to mean at a
temperature below approximately -150.degree. C. (-238.degree. F.).
The term "chilled fluid" is intended to be inclusive of fluids at
temperatures below approximately 22.degree. C. (70.degree. F.),
10.degree. C. (50.degree. F.), 0.degree. C. (32.degree. F.), or
-10.degree. C. (14.degree. F.) and fluids at cryogenic temperatures
(i.e., cryogenic fluids). Additionally, the term "chilled fluid" is
intended to be inclusive of liquids, gases, slurries, and
fluid-like mixtures.
[0014] Presently contemplated embodiments of an industrial plant,
such as a hydroelectric power plant, a chemical plant, or a
integrated combined cycle (IGCC) plant system include a chilled
fluid system configured to generate a chilled fluid to cool
components (e.g., electromechanical machines) of the plant system,
such as one or more generators. The chilled fluid system may be an
air separation unit configured to generate one or more chilled
fluids by compressing and separating component gases (e.g., oxygen,
nitrogen, or argon) from air. These chilled fluids may be cryogenic
fluids. Oxygen may be used for reactions within the plant system
(e.g., for gasification, combustion, etc.) whereas chilled nitrogen
(i.e., a substantially inert gas) and other chilled fluids may be
byproducts. As described below, the chilled fluids may be used to
directly or indirectly cool a generator within the IGCC system,
such as a generator driven by a gas turbine, steam turbine, hydro
turbine, or other engine. Using chilled fluids may increase the
efficiency of the system by utilizing the energy expended to
generate the chilled fluids to cool the generator or other
component within the system. The chilled fluids may be produced on
site, reducing or eliminating transportation costs associated with
some cooling systems. Moreover, some chilled fluids are
substantially nonreactive with the cooled component (e.g.,
generator), enabling lower tolerances for fittings within the
chilled fluid system. A working fluid may absorb heat from windings
of the generator and circulate through a heat exchanger to transfer
heat to the chilled fluid. In some embodiments, the working fluid
may transfer heat to an intermediate fluid, and the intermediate
fluid may transfer heat to the chilled fluid to protect the working
fluid from freezing. The working fluid and/or intermediate fluid
may be a liquid or a gas, such as air, hydrogen, water, deionized
water, glycol solution, oil, refrigerant, and so forth. The working
fluid and/or intermediate fluid may protect the generator from
undesirable temperatures. The heat exchanger may be within the
chilled fluid system or the generator. Alternatively, the heat
exchanger may be external to both. In some embodiments, the chilled
fluid may circulate through a first heat exchanger and a second
heat exchanger (e.g., cooler) to further cool the rotor and stator
of the generator. An electromechanical machine temperature
controller may control the flow of the chilled fluid through the
one or more heat exchangers to maintain a temperature of the
electromechanical machine (e.g., generator) below a threshold
temperature. In some embodiments, the electromechanical machine
temperature controller may control the chilled fluid to cool the
generator and to be used as a diluent in a gas turbine engine. The
electromechanical machine temperature controller may be configured
to warm the chilled fluid by adding heat and/or moderating the
chilled fluid with ambient air. The chilled fluid may also be used
as a prewarmed diluent in a gas turbine engine, gasifier, or other
reactor.
[0015] With the foregoing in mind, it may be beneficial to describe
an embodiment of a chilled fluid system that may incorporate the
components disclosed herein, that may be used, for example, in a
power production plant. FIG. 1 is a diagram of an embodiment of an
integrated gasification combined IGCC plant system 10 that may
produce and burn a synthetic gas, i.e., syngas to produce
electricity through a generator 64 or 68 cooled by a chilled fluid,
such as a chilled fluid from a chilled fluid system 40. Elements of
the IGCC plant system 10 may include a fuel source 12, such as a
solid feed, that may be utilized as a source of energy for the IGCC
plant system 10. The fuel source 12 may include coal, petroleum
coke, biomass, wood-based materials, agricultural wastes, tars,
coke oven gas, asphalt, heavy residues from a refinery, or other
carbon containing items. The solid fuel of the fuel source 12 may
be passed to a feedstock preparation unit 14. The feedstock
preparation unit 14 may, for example, resize or reshape the fuel
source 12 by chopping, milling, grinding, shredding, pulverizing,
briquetting, or pelletizing the fuel source 12 to generate
feedstock. Additionally, water, or other suitable liquids may be
added to the fuel source 12 in the feedstock preparation unit 14 to
create slurry feedstock. In other embodiments, no liquid is added
to the fuel source, thus yielding dry feedstock.
[0016] The feedstock prepared by the feedstock preparation unit 14
may be passed to a gasifier 16. The gasifier 16 may convert the
prepared fuel into syngas, (e.g., a combination of carbon monoxide
and hydrogen). This conversion may be accomplished by subjecting
the feedstock to a controlled amount of any moderator (e.g., liquid
water, carbon dioxide, nitrogen, and so forth) at elevated
pressures (e.g., from approximately 2 MPa to approximately 8.5 MPa)
and temperatures (e.g., approximately 700.degree. C. to
approximately 1600.degree. C.), depending on the type of gasifier
16 utilized. The heating of the feedstock during a pyrolysis
process may generate a solid (e.g., char) and residue gases (e.g.,
carbon monoxide, hydrogen, and nitrogen). The char remaining from
the feedstock from the pyrolysis process may only weigh up to
approximately 30% of the weight of the original feedstocks.
[0017] The combustion reaction in the gasifier 16 may include
introducing oxygen 18 to the char and residue gases. The char and
residue gases may react with the oxygen 18 to form carbon dioxide
and carbon monoxide, which provides heat for the subsequent
gasification reactions. The temperatures during the combustion
process may range from approximately 700.degree. C. to
approximately 1600.degree. C. In addition, steam may be introduced
into the gasifier 16. In essence, the gasifier utilizes steam and
oxygen 18 to allow some of the feedstock to be burned to produce
carbon monoxide and energy, which may drive a second reaction that
converts further feedstock to hydrogen and additional carbon
dioxide.
[0018] In this way, a resultant gas may be manufactured by the
gasifier 16. The resultant gas may include approximately 85% of
carbon monoxide and hydrogen, as well as CH.sub.4, HCl, HF, COS,
NH.sub.3, HCN, and H.sub.2S (based on the sulfur content of the
feedstock). This resultant gas may be termed "untreated syngas."
The gasifier 16 may also generate waste, such as slag 20, which may
be a wet ash material. As described in greater detail below, a gas
treatment unit 22 may be utilized to treat the untreated syngas.
The gas treatment unit 22 may scrub the untreated syngas to remove
the HCl, HF, COS, HCN, and H.sub.2S from the untreated syngas,
which may include separation of sulfur 24 in a sulfur processor 26
by, for example, an acid gas removal process in the sulfur
processor 26. Furthermore, the gas treatment unit 22 may separate
salts and fine particulates 28 from the untreated syngas via a
water treatment unit 30, which may utilize water purification
techniques to generate usable salts and fine particulates 28 from
the untreated syngas. An optional water-gas shift reaction may
increase the hydrogen concentration of the syngas. Subsequently, a
treated syngas may be generated from the gas treatment unit 22.
[0019] A gas processor 32 may be utilized to remove residual gas
components 34 from the treated syngas, such as ammonia and methane,
as well as methanol or other residual chemicals. However, removal
of residual gas components 34 from the treated syngas is optional
since the treated syngas may be utilized as a fuel even when
containing the residual gas components 34 (e.g., tail gas). At this
point, the treated syngas may include approximately 3% CO,
approximately 55% H.sub.2, and approximately 40% CO.sub.2, and may
be substantially stripped of H.sub.2S. This treated syngas may be
directed into a combustor 36 (e.g., a combustion chamber) of a gas
turbine engine 38 as combustible fuel, such that the turbine engine
38 can drive the generator 64 cooled by the chilled fluid (e.g.,
nitrogen, argon, or other inert gases cooled by the chilled fluid
system 40).
[0020] The IGCC plant system 10 may further include the chilled
fluid system 40 (e.g., an air separation unit (ASU)). The chilled
fluid system 40 may separate air into component gases using, for
example, cryogenic distillation techniques. The chilled fluid
system 40 may separate oxygen 18 from the air 42 supplied to it
from a supplemental air compressor 44 and may transfer the
separated oxygen 18 to the gasifier 16, sulfur processor 26, or
other components of the IGCC plant system 10 (e.g., furnace,
reactor, combustion engine, etc.). The chilled fluid system 40 may
separate the oxygen 18 from a chilled fluid 46 (e.g., nitrogen,
argon, and/or other inert gases). The chilled fluid system 40 may
direct the separated chilled fluid 46 to a chilled fluid conduit
48. The chilled fluid 46 may be used to cool components 50 of the
IGCC plant system 10. The components 50 may include
electromechanical machines, such as generators (e.g., electrical
generators 64 and 68), motors, power transformers, high voltage
bushings, or circuit breakers, or combinations thereof As discussed
in detail below, the chilled fluid 46 may be configured to cool
components 50 directly through contact with the components 50 or
indirectly through heat exchange with a working fluid. In some
embodiments, the chilled fluid 46 may be configured to circulate
through the chilled fluid conduit 48 and components 50 back to the
air separation unit 40. In other embodiments, the chilled fluid 46
may be configured to flow through the chilled fluid conduit 48 to
one or more components 50 of the IGCC plant system 10 without
returning to the chilled fluid system 40. For example, the chilled
fluid 46 may be used as a diluent, a purge gas, a coolant gas,
and/or a shielding gas for the gas turbine engine 38, the gasifier
16, the gas treatment unit 22, or other IGCC components.
Specifically, the chilled fluid 46 may be warmed (e.g., by having
absorbed heat from components 50) and directed along a diluent
conduit 52 to a diluent gas (DGAN) compressor 54. The DGAN
compressor 54 may process (e.g., warm and compress) the chilled
fluid 46 received from the chilled fluid system 40 to produce a
diluent gas 56. The diluent gas 56 may be compressed at least to a
pressure level equal to the combustor 36 and warmed to a sufficient
temperature so as to not interfere with proper combustion of the
syngas. The DGAN compressor 54 may direct the diluent gas 56 to the
combustor 36 or other parts of the gas turbine engine 38. As
described below, in some embodiments the chilled fluid 46 may flow
from a component 50 to the diluent conduit 52 rather than back to
the chilled fluid system 40.
[0021] The gas turbine engine 38, which drives the generator 64,
includes a turbine 58, a drive shaft 60, and a compressor 62, as
well as the combustor 36. The combustor 36 may receive compressed
air and fuel, such as the syngas, which may be injected under
pressure from fuel nozzles. This fuel may be mixed with diluent gas
56 from the DGAN compressor 54. In some embodiments, the combustor
36 may combust with oxygen 18 from the chilled fluid system 40
and/or oxygen in compressed air from the compressor 62. The
combustion creates hot pressurized exhaust gases directed towards
an exhaust outlet of the turbine 58. As the exhaust gases from the
combustor 36 pass through the turbine 58, the exhaust gases may
force turbine blades in the turbine 58 to rotate the drive shaft 60
along an axis of the gas turbine engine 38. As illustrated, the
drive shaft 60 may be connected to various components of the gas
turbine engine 38, including a compressor 62.
[0022] The drive shaft 60 may connect the turbine 58 to the
compressor 62, and the compressor 62 may include blades coupled to
the drive shaft 60. Thus, rotation of turbine blades in the turbine
58 may cause the drive shaft 60 connecting the turbine 58 to the
compressor 62 to rotate blades within the compressor 62. The
rotation of blades in the compressor 62 causes the compressor 62 to
compress air 42 received via an air intake in the compressor 62.
The compressed air may then be fed to the combustor 36 and mixed
with fuel (e.g., syngas) in a fuel-air mixture. In some
embodiments, the fuel-air mixture may be mixed with the compressed
diluent gas 56 to allow for higher efficiency combustion. The drive
shaft 60 may also be connected to the component 50, which may be a
load, such as the generator 64 cooled by the chilled fluid from the
chilled fluid system 40, for producing electrical power in the IGCC
plant system 10. Indeed, the component 50 may be any suitable
device that is powered by the rotational output of the gas turbine
engine 38.
[0023] The IGCC plant system 10 also may include a steam turbine
engine 66 and a heat recovery steam generation (HRSG) system 70.
The steam turbine engine 66 may drive a component 50, which may be
a stationary load cooled by the chilled fluid from the chilled
fluid system 40, such as the second generator 68 for generating
electrical power. However, the component 50 may be any suitable
device that is powered by the rotational output of the steam
turbine engine 66. In addition, although the gas turbine engine 38
and the steam turbine engine 66 may drive separate components 50 as
shown in the illustrated embodiment, the gas turbine engine 38 and
the steam turbine engine 66 may also be utilized in tandem to drive
a single component 50 (e.g., generator 68) via a single shaft.
Additionally, the chilled fluid conduit 48 may be configured to
cool any component 50 as described in detail below. The specific
configuration of the steam turbine engine 66, as well as the gas
turbine engine 38, may be implementation-specific and may include
any combination of sections.
[0024] Heated exhaust gas from the gas turbine engine 38 may be
directed into the HRSG 70 and used to heat water and produce steam
used to power the steam turbine engine 66. Exhaust from the steam
turbine engine 66 may be directed into a condenser 72. Condensate
from the condenser 72 may, in turn, be directed into the HRSG 70.
Again, exhaust from the gas turbine engine 38 may also be directed
into the HRSG 70 to heat the water from the condenser 72 and
produce steam.
[0025] As such, in combined cycle systems such as the IGCC plant
system 10, hot exhaust may flow through the gas turbine engine 38
to drive the second generator 68 through the HRSG 70. Heat from the
gas turbine engine 38, gasifier 16, and gas treatment unit 22 may
be directed to the HRSG 70, where it may be used to generate
high-pressure, high-temperature steam that flows through the steam
turbine engine 66 to drive the component 50 (e.g., second generator
68) coupled to the steam turbine engine 66 or different components
50 coupled to other equipment of the IGCC plant system 10. The
components 50, such as the electrical generators 64 and/or 68 may
warm during operation. The chilled fluid system 40 produces oxygen
18 for use in the IGCC plant system 10 and chilled fluid 46 as a
byproduct. The IGCC plant system 10 may be configured to use the
oxygen 18 for reactions and the chilled fluid 46 for cooling
components 50, thus utilizing both products of the chilled fluid
system 40 (e.g., air separation unit). Presently disclosed
embodiments integrate chilled fluid 46 of the chilled fluid system
40 with the components 50 (e.g., electrical generators 64 and/or
68) to increase the efficiency of the IGCC plant system 10. Cooling
the components 50 with the chilled fluid 46 enables the recovery of
at least some of the energy used by the chilled fluid system 40 to
compress and cool the chilled fluid 46. In this way, the chilled
fluid 46 may be configured to cool the components 50 without
significant additional energy input, thus utilizing the available
heat absorption capacity of the chilled fluid 46. For example, the
chilled fluid 46 may cool the components 50 more effectively than
ambient air 42 that is warmer than the chilled fluid 46. Also, the
chilled fluid may be substantially inert and reduce or eliminate
corrosion and maintenance of the components 50.
[0026] FIG. 2 illustrates an embodiment of a chilled fluid system
40 coupled to the component 50, which both may be part of the IGCC
plant system 10. The component 50 may include one or more
generators 64 and 68 of FIG. 1 or other components 50. While the
generator 64 is referred to as the component 50 of the embodiments
discussed below, the disclosed embodiments are not limited to the
generator 64. For example, the chilled fluid system 40 may be
coupled to other components 50, such as the generator 64, the
second generator 68, a motor, a power transformer, a high voltage
bushing, or a circuit breaker, or combinations thereof
[0027] The chilled fluid system 40 may be configured to generate
the chilled fluid 46 (e.g., nitrogen and/or argon). In some
embodiments, the chilled fluid system 40 is an air separation unit
configured to separate air 42 into oxygen 18, nitrogen, and other
gases, wherein the inert gases (e.g., nitrogen, argon, etc.) may be
used as the chilled fluid 46. The chilled fluid system 40 may
generate the chilled fluid 46 from the air 42 in a vessel 80 (e.g.,
distillation column) The chilled fluid 46 may be directed to a
reservoir 82. The reservoir 82 may store the chilled fluid 46 used
to directly or indirectly cool the generator 64. In some
embodiments, the reservoir 82 is configured to circulate at least
some of the chilled fluid 46 with the vessel 80. The chilled fluid
46 may be at cryogenic temperatures (e.g., below approximately
-196.degree. C.) within the reservoir 82. Alternatively, the
reservoir 82 may be configured to warm the chilled fluid 46 to a
suitable temperature (e.g., between approximately -20.degree. C. to
20.degree. C.) to cool the generator 64 within an operational
temperature range. The operational temperature range may be between
approximately -10.degree. C. to 200.degree. C.
[0028] The chilled fluid 46 may be directed from the reservoir 82
to a first heat exchanger 84 to cool a working fluid 86 from the
generator 64. The working fluid 86 may circulate through a coolant
circuit 88 to absorb heat from within the generator casing 90, such
as heat from windings 92. The windings 92 may be a component of a
rotor 94, a stator 96, and/or other parts that generate electricity
or a field. The windings 92 may warm by resistive heating during
operation of the generator 64. The coolant circuit 88 may include
fans or pumps configured to direct the working fluid 86 to the
first heat exchanger 84. The absorbed heat of the working fluid 86
may be transferred to the chilled fluid 46 within the first heat
exchanger 84. In this way, the chilled fluid 46 directly cools the
working fluid 86 and indirectly cools the winding 92 within the
generator 64 as the working fluid 86 circulates through the coolant
circuit 88. As a result of the heat exchange with the chilled fluid
46, the working fluid 86 may reenter the coolant circuit 88 at a
lower temperature than the temperature at which the working fluid
86 left the coolant circuit 88. The working fluid 86 (i.e., first
heat transfer fluid) may be a gas or liquid, such as air, hydrogen,
water, deionized water, glycol solution, oil, refrigerant, and so
forth. In some embodiments, the coolant circuit 88 may be a gas
ventilation circuit configured to cool the rotor 94 and stator 96
substantially by convection. For example, the working fluid 86 may
be air that flows about the chilled fluid conduit 48 in the first
heat exchanger 84 and about the rotor 94 and stator 96. In some
embodiments, chilled fluid 46 may directly cool the stator 96
without the working fluid 86.
[0029] The first heat exchanger 84 may be disposed in different
configurations to facilitate heat exchange between the chilled
fluid 46 and working fluid 86. In some embodiments, the first heat
exchanger 84 may include, but is not limited to a shell and tube,
plate, plate and shell, or spiral heat exchanger. Additionally, the
chilled fluid 46 and working fluid 86 may flow through the first
heat exchanger 84 in a parallel or counter-current direction. The
chilled fluid 46 may flow through the first heat exchanger 84 in
either a liquid or gaseous state. The temperature of the chilled
fluid 46 may be a cryogenic temperature (e.g., the boiling point of
liquid nitrogen at atmospheric pressure: -196.degree. C.; or the
boiling point of liquid argon at atmospheric pressure: -185.degree.
C.), or a temperature below approximately -100.degree. C.,
-50.degree. C., -15.degree. C., 0.degree. C., 10.degree. C.,
20.degree. C., or an ambient temperature.
[0030] In some embodiments, an electromechanical machine
temperature controller 98 may be configured to control a heat
exchange system 99 that includes the chilled fluid system 40 and
first heat exchanger 84. The electromechanical machine temperature
controller 98 may include one or more valves, memory, and a
processor. The memory may be a machine readable media configured to
store code or instructions to be used by the processor to control
the one or more valves. The one or more valves may be configured to
adjust the flow rates of the chilled fluid 46, working fluid 86,
other fluids (e.g., intermediate fluids) used within the heat
exchange system 99, or combinations thereof In some embodiments,
the electromechanical machine temperature controller 98 includes
one or more sensors to monitor the temperature of the chilled fluid
46 and/or working fluid 86. The electromechanical machine
temperature controller 98 may be configured to control the heat
exchange system 99 by adjusting the one or more valves based at
least in part on the sensed temperatures received by the
electromechanical machine temperature controller 98.
[0031] The electromechanical machine temperature controller 98 may
be configured to circulate the chilled fluid 46 directly through
the first heat exchanger 84. However, extremely low temperatures
may reduce the performance of the generator 64. For example,
extremely low temperatures may reduce the ductility of a material,
increase the viscosity of lubricants or the working fluid 86, or
freeze the working fluid 86, or combinations thereof. A
ductile-brittle transition temperature (DBTT) of a metal indicates
a low temperature at which the metal has a pre-determined
brittleness. In some embodiments, the electromechanical machine
temperature controller 98 is configured to circulate the chilled
fluid 46 at temperatures above the DBTT (e.g., -10.degree. C.)
through the first heat exchanger 84. The electromechanical machine
temperature controller 98 may be configured to adjust the flow rate
of the chilled fluid 46 to control the temperature of the working
fluid 86 (e.g., primary coolant). The chilled fluid 46 may exchange
heat with the warmer working fluid 86 (i.e., primary coolant),
which absorbs heat from the generator 92 through the coolant
circuit 88. In some embodiments, the chilled fluid 46 has a lesser
heat capacity than the working fluid 86. In some embodiments, the
electromechanical machine temperature controller 98 may circulate
an intermediate fluid 101 through the reservoir 82 and first heat
exchanger 84 to protect the materials of the first heat exchanger
84 and generator 64 from exposure to temperatures near or below the
DBTT. In some embodiments, the working fluid 86 is configured to
absorb heat from the generator 92 through the cooling circuit 88,
the intermediate fluid 101 is configured to absorb heat from the
working fluid 86 in the first heat exchanger 84, and the chilled
fluid 46 is configured to absorb heat from the intermediate fluid
101 in the reservoir 82. Using the intermediate fluid 101 may also
enable the maintenance of lubricants at desirable viscosity levels
and protect the working fluid 86 from freezing and/or increasing
beyond a threshold viscosity. The intermediate fluid 101 (i.e.,
second heat transfer fluid) may be a gas or liquid, such as air,
hydrogen, water, deionized water, glycol solution, oil,
refrigerant, and so forth.
[0032] In some embodiments, the first heat exchanger 84 may be
disposed within the chilled fluid system 40 as shown by the dashed
lines (- - -). In some embodiments, the reservoir 82 may include
part of the first heat exchanger 84. For example, the reservoir 82
may be a pool of the chilled fluid 46 and the working fluid 86 may
circulate through pipes of the first heat exchanger 84 immersed in
the chilled fluid 46. Disposing the first heat exchanger 84 within
the chilled fluid system 40 may enable the same size winding 92 to
be disposed within a smaller generator casing 90 or larger windings
92 to be disposed within the same size generator casing 90. The
size of the windings 92 may be related to the electrical output
capacity. For example, large windings 92 may be capable of
producing a greater electrical output than small windings 92.
[0033] In some embodiments, the first heat exchanger 84 may be
disposed within the generator casing 90 as shown by the dash-dot
lines (-.cndot.-.cndot.-). This may enable the chilled fluid system
40 to readily replace a previously coupled cooling system or to
improve an existing first heat exchanger 84. The chilled fluid
system 40 coupled to an existing generator 64 may be configured to
increase the efficiency and/or output of the existing generator 64
by decreasing the temperature of the circulated working fluid 86
due to the low temperature of the chilled fluid 46 of the chilled
fluid system 40. In this manner, the efficiency and/or output of
the existing generator may be increased without substantially
altering the first heat exchanger 84 or generator 64. The low
temperature of the chilled fluid 46 may enable the working fluid 86
to transfer more heat to the chilled fluid 46 compared to an air
cooled system at ambient temperature.
[0034] The first heat exchanger 84 of some embodiments may be
disposed external to both the chilled fluid system 40 and the
generator 64. Disposing the first heat exchanger 84 externally may
increase the flexibility of the IGCC plant system 10 by enabling
the heat exchanger 84 to be readily replaced, modified, or
maintained. An externally disposed first heat exchanger 84 may be
readily used for multiple purposes within the IGCC plant system 10.
An external heat exchanger 84 may also increase the modularity of
components within the IGCC plant system 10.
[0035] As discussed above, the electromechanical machine
temperature controller 98 along the chilled fluid conduit 48 may be
configured to circulate the chilled fluid 46 or an intermediate
fluid 101 between the reservoir 82 and the first heat exchanger 84.
The electromechanical machine temperature controller 98 may be
disposed along the chilled fluid conduit 48 at a first inlet 100 or
a first outlet 102 of the first heat exchanger 84. Like the first
heat exchanger 84, the electromechanical machine temperature
controller 98 may be disposed within the chilled fluid system 40,
the generator 64, the first heat exchanger 84, or external to these
systems of the IGCC plant system 10. The electromechanical machine
temperature controller 98 may be configured to control the heat
exchange between the chilled fluid 46 and the working fluid 86 to
maintain a temperature of the generator 64 below a threshold
temperature (e.g., 100.degree. C. to 200.degree. C.). In some
embodiments, electromechanical machine temperature controller 98 is
configured to maintain the temperature of the rotor 94, stator 96,
or the windings 92 below a threshold temperature. The windings 92
may warm due to resistance heating from the produced current
through the windings 92. Resistance may increase with temperature
such that warmer windings 92 may have greater resistance than
cooler windings 92. Cooling the windings 92 may lower the
temperature and resistance within the windings 92 so that less of
the output of the generator 64 is lost due to resistance heating,
thus increasing the efficiency. Cooling the windings 92 may also
extend or improve the thermal capability of the windings 92. A
thermal capability may be an amount of heat generated within the
windings 92 to reach a threshold temperature. For example, the
generator 64 producing a first output without heat exchange with
the chilled fluid may have windings 92 with a first thermal
capability. Cooling the generator 64 with the chilled fluid may
extend the thermal capability of the windings 92 to a second
thermal capability so that the generator 64 may produce a second
output greater than the first output and the windings 92 may absorb
additional heat without exceeding the threshold temperature.
[0036] The electromechanical machine temperature controller 98 may
control the heat exchange of the heat exchange system 99 at least
by adjusting the flow rate of the chilled fluid 46, the temperature
of the chilled fluid 46, or combinations thereof The
electromechanical machine temperature controller 98 may restrict
the flow rate and/or warm the chilled fluid 46 to decrease the heat
exchange between the chilled fluid 46 and working fluid 86.
Likewise, the electromechanical machine temperature controller 98
may increase the flow rate of the chilled fluid 46 to increase the
heat exchange. In some embodiments, the electromechanical machine
temperature controller 98 may be configured to warm the chilled
fluid 46 by inductive heating, convection, or other heat transfer.
The electromechanical machine temperature controller 98 may direct
the chilled fluid 46 near a warm component 50 (e.g., generators 64,
68) for purposes of cooling, resulting in heat transfer to the
chilled fluid 46.
[0037] In some embodiments, due to the low (e.g., cryogenic)
temperature of the chilled fluid 46 in the reservoir 82, a bypass
conduit 104 may be fluidly coupled between the first inlet 100 and
the first outlet 102 to bypass the reservoir 82. The
electromechanical machine temperature controller 98 may be
configured to recirculate some of the chilled fluid 46 or
intermediate fluid 101 from the first outlet 102 to the first inlet
100 along the bypass conduit 104 rather than through the reservoir
82. The recirculated chilled fluid 46 may warm the chilled fluid 46
directed to the first heat exchanger 84. In this way, the
electromechanical machine temperature controller 98 may be
configured to maintain a temperature of the generator 64 at an
operational temperature between a threshold (e.g., maximum)
temperature (e.g., 200.degree. C.) and the ductile-brittle
transition temperature (e.g., -10.degree. C.). For example,
recirculating at least some of the chilled fluid 46 through the
bypass conduit 104 may raise the temperature of the chilled fluid
46 flowing through the first heat exchanger 84 from approximately
-196.degree. C. to approximately 5.degree. C. or higher.
[0038] In some embodiments as illustrated in FIG. 3, the chilled
fluid system 40 may be configured to cool a component 50 (e.g., the
generator 64, 68) via heat exchange with the first heat exchanger
84 as discussed above with FIG. 1 and with a second heat exchanger
(e.g., cooler 110). For example, the first heat exchanger 84 and
coolant circuit 88 may be configured to cool the rotor 94 and the
cooler 110 may be configured to cool the stator 96. Alternatively,
only the cooler 110 may be configured to cool the generator 64, 68.
The cooler 110 may be coupled between the chilled fluid system 40
and generator 64, 68 in various configurations. The cooler 110 may
be disposed within the chilled fluid system 40, within the
generator casing 90, or external to both. In some embodiments, the
cooler 110 may include, but is not limited to an evaporative cooler
(e.g., cooling tower), shell and tube heat exchanger, plate and/or
shell heat exchanger, or spiral heat exchanger. Additionally, the
chilled fluid 46 and a second working fluid 112 may flow through
the second heat exchanger in a parallel or counter-current
direction. The chilled fluid 46 may flow to the cooler 110 in
either a liquid or gaseous state.
[0039] The heat exchange system 99 controlled by the
electromechanical machine temperature controller 98 may include the
cooler 110 and/or the first heat exchanger 84. The
electromechanical machine temperature controller 98 may be
configured to circulate the chilled fluid 46 from the reservoir 82
to a cooler 110 fluidly coupled to the stator 96. In some
embodiments, the chilled fluid 46 and the second working fluid 112
may exchange heat within the cooler 110, and the cooler 110 may
circulate the second working fluid 112 to indirectly cool the
stator 96. The chilled fluid 46 may be configured to circulate back
to the reservoir 82. In other embodiments, the cooler 110 may
circulate the chilled fluid 46 to directly cool (e.g., contact) the
stator 96 without using the second working fluid 112. The stator
winding 92 may be electrically insulated and coiled about a core.
The cooler 110 may direct the chilled or second working fluids 46
or 112 through the core or through hollow strands of the stator
winding 92. The second working fluid 112 (e.g., third heat transfer
fluid) may be a gas or liquid, such as air, hydrogen, water,
deionized water, glycol solution, oil, refrigerant, and so forth.
Presently contemplated embodiments include a deionized water cooler
110 configured to circulate deionized water, (e.g., second working
fluid 112) through the stator winding 92 to absorb heat from the
stator winding 92. The chilled fluid 46 may be configured to be a
heat sink within the deionized water cooler 110 to absorb the heat
from the deionized water so that the deionized water may circulate
through the stator winding 92 to absorb additional heat.
[0040] As discussed above, the chilled fluid 46 from the vessel 80
or in the reservoir 82 may be at cryogenic temperatures. The
chilled fluid 46 may be a liquid or a gas that may be warmed before
exchanging heat with the second working fluid 112 or generator 64,
68 to protect materials from undesirably low temperatures that may
affect properties of the generator 64, such as the ductility of
metals or the viscosity of fluids. The electromechanical machine
temperature controller 98 may be configured to warm the chilled
fluid 46 directed to the cooler 110. The electromechanical machine
temperature controller 98 may direct the chilled fluid 46 to be
warmed by absorbing some heat from a system (e.g., gas treatment
unit 22 of FIG. 1) within the IGCC plant system 10. In some
embodiments, the electromechanical machine temperature controller
98 may circulate an intermediate fluid 101 between the reservoir 82
and the cooler 110 where the intermediate fluid 101 is at an
intermediate temperature between the temperature of the chilled
fluid 46 and the temperature of the second working fluid 112. The
electromechanical machine temperature controller 98 is configured
to control the flow rate of the chilled fluid 46 and/or the
intermediate fluid 101 to control the temperature of the fluid
(e.g., chilled fluid 46 or second working fluid 112), which is
circulated by the cooler 110 circulates through the generator
64.
[0041] In some embodiments, the electromechanical machine
temperature controller 98 may be configured to circulate the
chilled fluid 46 directly through the generator 64, 68 without a
working fluid 86 or second working fluid 112. Circulating the
chilled fluid 46 directly through the generator 64, 68 may reduce
maintenance costs of the generator 64, 68. For example, argon and
nitrogen are generally chemically inactive at operating
temperatures of the generator 64, 68, thus an argon chilled fluid
46 or a nitrogen chilled fluid 46 may not react with the parts
within the generator 64, 68. Additionally, argon and nitrogen may
displace reactive fluids such as oxygen, hydrogen, and water within
the generator 64, 68 and generator casing 90 to reduce reactions
with the reactive fluids. The use of generally inert chilled fluids
46 may decrease maintenance costs due to corrosion and
oxidation.
[0042] The rated power output of the generator (e.g., generator 64,
68) is typically based on the size of the generator. For example, a
large generator may have a greater rated output than a small
generator. A heat exchange system 99 for the generator may vary
based at least in part on the rated output and size of the
generator. Several types of heat exchange systems use one or more
heat exchangers and working fluids. Each type of heat exchange
system may have a base capacity and efficiency. In a first heat
exchange system, a low rated output generator may be cooled by
circulating air forced through ducts and the rotor 94. The stator
winding 92 may be electrically insulated and coiled about a ducted
core. The stator winding 92 may be cooled by conduction through the
insulation to the air and the ducted core. In a second heat
exchange system, a larger rated output generator may be cooled by
circulating pressurized hydrogen through cooling passages in the
stator 96 and rotor 94. The generator may be sealed to prevent
leaks that may generally cause loss of coolant, corrosion, or
oxidation. The second heat exchange system may enable more heat to
be removed from the generator than the first heat exchange system
alone. In a third heat exchange system, a larger rated output
generator may cool the stator 96 by an additional system, such as
the cooler 110 to circulate a liquid (e.g., de-ionized water)
through the ducts and/or hollow conduits within the stator winding
92. The third heat exchange system may enable more heat to be
removed from the generator 64 than the second heat exchange system.
Additionally, the third heat exchange system may be used together
with the first or second heat exchange system. The third heat
exchange system may be larger than the first or second heat
exchange system. In some embodiments, circulating the chilled fluid
46 through the first heat exchanger 84 rather than air may increase
the heat removed via heat exchange, so that the first heat exchange
system may replace a second or third heat exchange system.
Similarly, using the chilled fluid 46 rather than the pressurized
hydrogen in the second heat exchange system may enable the second
heat exchange system to replace a third heat exchange system. In
this way, integrating the chilled fluid system 40 may decrease the
size and/or complexity of the heat exchange system 99 used to
remove heat from the generator 64, 68. This may also reduce
maintenance and installation costs associated with the generator
64, 68.
[0043] FIG. 4 illustrates an embodiment having the
electromechanical machine temperature controller 98 configured to
control the heat exchange system 99 and use chilled fluid 46 from
the chilled fluid system 40 for other purposes. After absorbing
heat from the coolant circuit 88, the chilled fluid 46 exits the
coolant circuit 88 as a warmed fluid 120. In some embodiments, the
electromechanical machine temperature controller 98 may circulate
the warmed fluid 120 back to the chilled fluid system 40 as shown
by the dashed lines. Alternatively, the electromechanical machine
temperature controller 98 may direct the warmed fluid 120 elsewhere
in the IGCC plant system 10. In some embodiments, the chilled fluid
46 may be bled at the bleed inlet 122 into air used as the working
fluid 86. The chilled fluid 46 may cool the working fluid 86
directly. In some embodiments, the chilled fluid 46 may pre-cool
the working fluid 86 before the working fluid 86 enters the coolant
circuit 88 and/or stator winding 92. Bleeding the chilled fluid 46
into the bleed inlet 122 may also provide a clean and dry
ventilation source. Bleeding a substantially inert chilled fluid 46
(e.g., nitrogen, argon) into the bleed inlet 122 may displace
oxygen, hydrogen, and/or water and reduce maintenance costs of the
coolant circuit 88 due to corrosion and oxidation.
[0044] In another example, the electromechanical machine
temperature controller 99 may direct the warmed fluid 120 through a
diluent conduit 52 to be directed to the gas turbine engine 38 as a
diluent gas 56. In some embodiments, the diluent gas 56 may be
directed to the compressor 62 to dilute the air sent to the
combustor 36. In some embodiments, the diluent gas 56 may be
directed to the combustor 36 and/or turbine 58 to dilute emissions,
cool the exhaust gases, cool components, and/or purge fuel lines.
The diluent gas 56 may flow through a filter 124 to remove
particulates or contamination from the diluent gas 56 and protect
the gas turbine engine 38. The diluent gas (DGAN) compressor 54
pressurizes the diluent gas 56 to approximately the same pressure
as the combustor 36 or turbine 58. In some embodiments, heat may be
added to the diluent gas 56, so that the diluent gas is
approximately the temperature of the compressed air and fuel
injected into the combustor 36. However, the relative quantity of
heat added to the diluent gas 56 may be small, because the chilled
fluid 46 has absorbed heat from the generator 64 prior to entering
the diluent conduit 52 as the warmed fluid 120. In some
embodiments, the drive shaft 60 coupled to the turbine 58 may drive
the compressor 62 and the component 50 (e.g., generator 64). In
other embodiments, the component 50 (e.g., second generator 68) may
be driven by another turbine (e.g., steam turbine 66 of FIG.
1).
[0045] As discussed above, the electromechanical machine
temperature controller 98 may be configured to warm the chilled
fluid 46 by absorbing heat from a system within the IGCC plant
system 10. In some embodiments, the electromechanical machine
temperature controller 98 may be configured to adjust the
temperature of the chilled fluid 46 by moderating the chilled fluid
46 with air 42. Air 42 may be introduced to the chilled fluid 46 to
produce a chilled mixture 126. The chilled mixture 126 may be
warmer than the chilled fluid 46 and cooler than the generator 64.
The electromechanical machine temperature controller 98 may be
configured to moderate the chilled fluid 46 with air 42 to protect
the coolant circuit 88, winding 92, or other part of the generator
64 from undesirable low temperatures (e.g., cryogenic
temperatures). The chilled mixture 126 may flow through the coolant
circuit 88 and be directed to the chilled fluid system 40, the
bleed inlet 122, or the diluent conduit 52.
[0046] The embodiments of FIG. 4 in which the chilled fluid 46 is
used in the IGCC plant system 10 after cooling the generator 64 may
be used together with embodiments described above in FIGS. 2 and 3.
For example, the chilled fluid system 40 may be configured to cool
the generator 64, 68 through any of the configurations of the first
heat exchanger 84 of FIG. 2, where some of the warmed fluid 120 may
be directed elsewhere as diluent gas 56 as described above with
FIG. 4. As another example, the electromechanical machine
temperature controller 98 may direct a part of the chilled fluid 46
from the chilled fluid system 46 through the generator 64, 68 to
another system (e.g., gas turbine engine 38) within the IGCC plant
system 10 while another part of the chilled fluid 46 is directed to
the cooler 110 to cool the stator 96.
[0047] Presently contemplated embodiments include systems and
methods for generating a chilled fluid using a chilled fluid system
(e.g., air separation unit), removing heat from a generator via
heat exchange with the chilled fluid (e.g., inert gas from chilled
fluid system), and controlling the heat exchange to maintain a
temperature of the generator below a first threshold temperature.
As discussed above, the chilled fluid may be a liquid or a gas,
such as nitrogen, argon, or helium. The chilled fluid also may be a
cryogenic fluid. The first threshold temperature may be
approximately 100.degree. C., 125.degree. C., 150.degree. C.,
175.degree. C., or 200.degree. C. A working fluid may be configured
to exchange heat with the chilled fluid and the generator to remove
heat. The method may include circulating the working fluid and
chilled fluid through a heat exchange system (e.g., heat exchanger
or chiller). In some embodiments, controlling the heat exchange
includes directing the working fluid to interface directly with a
rotor and/or a stator of the generator. In some embodiments, the
method includes using the chilled fluid as a diluent in a gas
turbine engine. Moreover, the method may include moderating the
chilled fluid with a gas (e.g., ambient air) that is warmer than
the chilled fluid. In some embodiments, the method includes warming
the chilled fluid to a second threshold temperature prior to
removing heat from the generator. The second threshold temperature
may be approximately -20.degree. C., -10.degree. C., 0.degree. C.,
or 10.degree. C. Warming the chilled fluid to the second threshold
temperature may protect the generator from temperatures near the
DBTT and protect the fluids from freezing or becoming too
viscous.
[0048] Technical effects of the invention include integrating a
chilled fluid system with components of an IGCC plant system, so
that a generated chilled fluid may cool a generator or other
components. The chilled fluid system (e.g., air separation unit)
may be configured to produce a primary product, such as oxygen, and
produce the chilled fluid as a byproduct (e.g., nitrogen, argon, or
other inert gas). Using the chilled fluid within the system to cool
a component increases the efficiency of the IGCC plant system by
utilizing the energy used to generate the chilled fluid to cool a
warm component, such as a generator. Cooling the generator may
increase the efficiency by lowering the energy lost due to the
electrical resistance within the generator. Circulating the chilled
fluid may increase the heat removed from the generator to increase
the generated output by removing or extending thermal limits in the
windings. Using the chilled fluid may enable the generator to be
cooled with a smaller and/or less complex heat exchange system. For
example, circulating the chilled fluid may increase the rated
output for a generator using liquid cooled bushings. Using the
chilled fluid from the chilled fluid system within the IGCC plant
may reduce the frame size and complexity of the generator, because
on-base coolers are no longer used for the generator. Reducing the
size of the heat exchange system or using a heat exchanger external
to the generator casing, rather than internal, may reduce the size
of a generator casing and frame or increase the rated output of a
generator with the same casing and frame. Circulating the chilled
fluid directly through the generator may reduce maintenance costs
due to decreased corrosion and oxidation due to water leakage.
Directing the chilled fluid from the generator to the gas turbine
engine as a diluent gas may decrease the energy used to heat the
diluent gas prior to entering the combustor.
[0049] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they have structural elements that do not differ
from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal language of the claims.
* * * * *