U.S. patent application number 13/209914 was filed with the patent office on 2012-03-22 for multipurpose thermal power plant system.
This patent application is currently assigned to Hitachi, Ltd.. Invention is credited to Nobuyoshi MISHIMA, Takashi Sugiura.
Application Number | 20120067048 13/209914 |
Document ID | / |
Family ID | 44763826 |
Filed Date | 2012-03-22 |
United States Patent
Application |
20120067048 |
Kind Code |
A1 |
MISHIMA; Nobuyoshi ; et
al. |
March 22, 2012 |
Multipurpose Thermal Power Plant System
Abstract
To provide a multipurpose thermal power plant system capable of
capturing moisture and carbon dioxide in large quantities at a low
cost from exhaust gas of an oxygen combustion boiler. To use an
oxygen combustion boiler 1, an oxygen separator 6, a coal fuel feed
apparatus 7, a steam turbine 2, a generator 3, denitrification
equipment 10, a gas heat exchanger 11, a condensate cooler 12 for
cooling exit gas of the gas heat exchanger with a condensate at an
exit of a condenser which is a part of steam cycle water of the
turbine, a dust collector 13, a desulfurizer 14, a cooling
water-desalination apparatus 15, and a carbon dioxide liquefier 16,
to utilize the characteristic that main components of exhaust gas
of the oxygen combustion boiler 1 after combustion are carbon
dioxide gas and steam, and to simultaneously capture moisture and
carbon dioxide in the gas by cooling and compressing the exhaust
gas. And to install a water feed system for utilizing the captured
moisture as cycle water of a steam-water cycle of the steam
turbine.
Inventors: |
MISHIMA; Nobuyoshi;
(Hitachi, JP) ; Sugiura; Takashi; (Hitachinaka,
JP) |
Assignee: |
Hitachi, Ltd.
Tokyo
JP
|
Family ID: |
44763826 |
Appl. No.: |
13/209914 |
Filed: |
August 15, 2011 |
Current U.S.
Class: |
60/670 |
Current CPC
Class: |
F22B 1/003 20130101;
F01K 23/06 20130101; Y02E 20/344 20130101; Y02E 20/34 20130101;
Y02E 20/185 20130101; Y02E 20/18 20130101; F01K 23/10 20130101 |
Class at
Publication: |
60/670 |
International
Class: |
F01K 13/00 20060101
F01K013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 21, 2010 |
JP |
2010-210356 |
Claims
1. A multipurpose thermal power plant system comprising an oxygen
combustion boiler, a steam turbine driven by steam generated by the
oxygen combustion boiler, a generator driven by the steam turbine,
an oxygen separator for generating oxygen fed to the oxygen
combustion boiler, a fuel feed apparatus for feeding fossil fuel
composed of carbon, hydrogen, a small amount of sulfur, and
nitrogen to the oxygen combustion boiler, a denitrification
equipment for removing nitrogen oxides in the exhaust gas of the
oxygen combustion boiler, a gas heat exchanger for performing heat
exchange between the boiler exhaust gas and recirculation boiler
exhaust gas including oxygen, a condensate cooler for cooling
exhaust gas at an exit of the gas heat exchanger with a condensate
of the steam turbine, a recirculation system for recirculating
boiler exhaust gas at an exit of the condensate cooler to the
oxygen combustion boiler, an oxygen injection system for feeding
oxygen from the oxygen separator to the recirculation system, a
dust collector for removing dust from the exhaust gas at the exit
of the condensate cooler, a desulfurizer for removing sulfur in
boiler exhaust gas from the dust collector, a cooling
water-desalination apparatus for producing water by cooling boiler
exhaust gas from the desulfurizer, a carbon dioxide liquefier for
obtaining carbon dioxide by compressing boiler exhaust gas at an
exit of the cooling water-desalination apparatus, a carbon dioxide
storage tank for storing liquefied carbon dioxide obtained by the
carbon dioxide liquefier, a fresh water tank for capturing water
generated by the cooling water-desalination apparatus, and a water
feed system for feeding water of the fresh water tank to the steam
turbine system as steam cycle water of the steam turbine.
2. A multipurpose thermal power plant system comprising an oxygen
combustion boiler, a steam turbine driven by steam generated by the
oxygen combustion boiler, a generator driven by the steam turbine,
an oxygen separator for generating oxygen fed to the oxygen
combustion boiler, a fuel feed apparatus for feeding fossil fuel
like liquefied natural gas composed of carbon and hydrogen to the
oxygen combustion boiler, a gas heat exchanger for performing heat
exchange between the boiler exhaust gas and recirculation boiler
exhaust gas including oxygen, a condensate cooler for cooling
exhaust gas at an exit of the gas heat exchanger with a condensate
of the steam turbine, a recirculation system for recirculating
boiler exhaust gas at an exit of the condensate cooler to the
oxygen combustion boiler, an oxygen injection system for feeding
oxygen from the oxygen separator to the recirculation system, a
cooling water-desalination apparatus for producing water by cooling
boiler exhaust gas from the condensate cooler, a carbon dioxide
liquefier for obtaining carbon dioxide by compressing boiler
exhaust gas at an exit of the cooling water-desalination apparatus,
a carbon dioxide storage tank for storing liquefied carbon dioxide
obtained by the carbon dioxide liquefier, a fresh water tank for
capturing water generated by the cooling water-desalination
apparatus, and a water feed system for feeding water of the fresh
water tank to the steam turbine system as steam cycle water of the
steam turbine.
3. A multipurpose thermal power plant system comprising an oxygen
combustion boiler, a steam turbine driven by steam generated by the
oxygen combustion boiler, a generator driven by the steam turbine,
an oxygen separator for generating oxygen fed to the oxygen
combustion boiler, a fuel feed apparatus for feeding hydrogen fuel
to the oxygen combustion boiler, a gas heat exchanger for
performing heat exchange between the boiler exhaust gas and
recirculation boiler exhaust gas including oxygen, a condensate
cooler for cooling exhaust gas at an exit of the gas heat exchanger
with a condensate of the steam turbine, a recirculation system for
recirculating boiler exhaust gas at an exit of the condensate
cooler to the oxygen combustion boiler, an oxygen injection system
for feeding oxygen from the oxygen separator to the recirculation
system, a cooling water-desalination apparatus for producing water
by cooling boiler exhaust gas from the condensate cooler, a fresh
water tank for capturing water generated by the cooling
water-desalination apparatus, and a water feed system for feeding
water of the fresh water tank to the steam turbine system as steam
cycle water of the steam turbine.
4. A multipurpose thermal power plant system comprising an oxygen
combustion boiler, a steam turbine driven by steam generated by the
oxygen combustion boiler, a generator driven by the steam turbine,
an oxygen separator for generating oxygen fed to the oxygen
combustion boiler, a fuel feed apparatus for feeding fossil fuel
composed of carbon to the oxygen combustion boiler, a gas heat
exchanger for performing heat exchange between the boiler exhaust
gas and recirculation boiler exhaust gas including oxygen, a
condensate cooler for cooling exhaust gas at an exit of the gas
heat exchanger with a condensate of the steam turbine, a
recirculation system for recirculating boiler exhaust gas at an
exit of the condensate cooler to the oxygen combustion boiler, an
oxygen injection system for feeding oxygen from the oxygen
separator to the recirculation system, a carbon dioxide liquefier
for obtaining carbon dioxide by compressing boiler exhaust gas from
the condensate cooler, and a carbon dioxide storage tank for
storing liquefied carbon dioxide obtained by the carbon dioxide
liquefier.
Description
CLAIM OF PRIORITY
[0001] The present application claims priority from Japanese patent
application JP 2010-210356 filed on Sep. 21, 2010, the content of
which is hereby incorporated by reference into this
application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a multipurpose thermal
power plant system and more particularly to a fossil fuel
combustion multipurpose thermal power plant system having a
function for simultaneously performing the three great functions of
water desalination, carbon dioxide capture, and power generation,
or simultaneously performing the power generation function and
water desalination function or carbon dioxide capture function.
[0004] 2. Description of Related Art
[0005] A thermal power plant having the water desalination function
for bleeding steam from the steam turbine cycle for generating
power, thereby producing fresh water from seawater is already put
into practical use. Furthermore, a coal fuel combustion thermal
power plant system simultaneously including not only the power
generation function and water desalination function but also a
function for compressing and cooling carbon dioxide included in the
boiler exhaust gas of an oxygen combustion boiler, thereby
capturing carbon dioxide is devised. For example, in Japanese
Patent Laid-open No. 2010-101587 (Patent document 1), in a thermal
power plant system including an oxygen combustion boiler, an oxygen
separator, a coal feed apparatus, a steam turbine, and a steam
turbine generator for utilizing that the main components of the
exhaust gas of the oxygen combustion boiler are carbon dioxide and
steam, using denitrification equipment, an oxygen preheater, a dust
collector, a desulfurizer, cooling and dehumidification equipment,
and a carbon dioxide liquefier, the constitution of a coal
combustion and oxygen combustion boiler for cooling exhaust gas,
removing moisture in the exhaust gas, and then capturing carbon
dioxide and the control method for the oxygen combustion boiler are
disclosed.
[0006] Patent document 1: Japanese Patent Laid-open No.
2010-101587
SUMMARY OF THE INVENTION
[0007] In Patent document 1, moisture generated by the cooling and
dehumidification equipment is discharged outside the system.
Regarding it, it is inferred that the quantity of moisture
generated by the cooling and dehumidification equipment is not
sufficient for effective use.
[0008] The main components of the exhaust gas from the oxygen
combustion boiler are carbon dioxide gas and steam. Namely, when
inputting oxygen gas in the air into the boiler as an oxygen source
for boiler fuel, unlike a conventional air combustion boiler forced
to input a large amount of unnecessary nitrogen gas in the air
which does not contribute to combustion into the boiler
simultaneously with oxygen gas in the air, in the case of the
oxygen combustion boiler, only oxygen from an exclusive oxygen
generation apparatus is used as a combustion oxygen source of the
boiler, so that in the boiler exhaust gas components, steam and
carbon dioxide which are produced due to oxidation of hydrogen,
carbon, and hydrocarbon which are the main components of the fuel
are the main components and excessive nitrogen gas in the air is
not included.
[0009] Thus, the exhaust gas is cooled and compressed, thereby
moisture and carbon dioxide in the gas can be captured
simultaneously. A large amount of moisture is included in the
exhaust gas of the oxygen combustion boiler, though moisture
generated by the conventional cooling and dehumidification
equipment is not in a large amount, thus a large amount of moisture
in the exhaust gas is discharged outside the system without being
used effectively. If moisture obtained by cooling the exhaust gas
can be captured in a large amount at a low cost, the captured
moisture can be utilized as cycle water of the steam-water cycle of
the steam turbine. However, in the conventional system, the amount
of water captured is not sufficient for utilization as cycle water
of the steam-water cycle of the steam turbine.
[0010] An object of the present invention is to provide a
multipurpose thermal power plant system capable of capturing
moisture and carbon dioxide in large quantities at a low cost from
the exhaust gas of the oxygen combustion boiler.
[0011] The multipurpose thermal power plant system of the present
invention, when using fossil fuel composed of carbon, hydrogen, a
very small amount of sulfur, and nitrogen as fuel, includes an
oxygen combustion boiler, a steam turbine, a generator, an oxygen
separator for generating oxygen fed to the oxygen combustion
boiler, a fuel feed apparatus for feeding fossil fuel composed of
carbon, hydrogen, a very small amount of sulfur, and nitrogen to
the oxygen combustion boiler, denitrification equipment for
removing nitrogen oxide in the exhaust gas of the oxygen combustion
boiler, a gas heat exchanger for performing heat exchange between
boiler exhaust gas and recirculation boiler exhaust gas including
oxygen, a condensate cooler for cooling exhaust gas at the exit of
the gas heat exchanger with condensate of the steam turbine, a
recirculation system for recirculating boiler exhaust gas at the
exit of the condensate cooler to the oxygen combustion boiler, an
oxygen injection system for feeding oxygen from the oxygen
separator to the recirculation system, a dust collector for
removing dust from exhaust gas at the exit of the condensate
cooler, a desulfurizer for removing sulfur in the boiler exhaust
gas from the dust collector, a cooling water-desalination apparatus
for producing water by cooling boiler exhaust gas from the
desulfurizer, a carbon dioxide liquefier for obtaining carbon
dioxide by compressing boiler exhaust gas at the exit of the
cooling water-desalination apparatus, a carbon dioxide storage tank
for storing liquefied carbon dioxide obtained by the carbon dioxide
liquefier, a fresh water tank for capturing water generated by the
cooling water-desalination apparatus, and a water feed system for
feeding water of the fresh water tank to the steam turbine system
as steam cycle water of the steam turbine.
[0012] When using fossil fuel such as liquefied natural gas
composed of carbon and hydrogen as fuel, the multipurpose thermal
power plant system of the present invention includes an oxygen
combustion boiler, a steam turbine, a generator, an oxygen
separator for generating oxygen fed to the oxygen combustion
boiler, a fuel feed apparatus for feeding fossil fuel such as
liquefied natural gas composed of carbon and hydrogen to the oxygen
combustion boiler, a gas heat exchanger for performing heat
exchange between boiler exhaust gas and recirculation boiler
exhaust gas including oxygen, a condensate cooler for cooling
exhaust gas at the exit of the gas heat exchanger with condensate
of the steam turbine, a recirculation system for recirculating
boiler exhaust gas at the exit of the condensate cooler to the
oxygen combustion boiler, an oxygen injection system for feeding
oxygen from the oxygen separator to the recirculation system, a
cooling water-desalination apparatus for producing water by cooling
boiler exhaust gas from the condensate cooler, a carbon dioxide
liquefier for obtaining carbon dioxide by compressing boiler
exhaust gas at the exit of the cooling water-desalination
apparatus, a carbon dioxide storage tank for storing liquefied
carbon dioxide obtained by the carbon dioxide liquefier, a fresh
water tank for capturing water generated by the cooling
water-desalination apparatus, and a water feed system for feeding
water of the fresh water tank to the steam turbine system as steam
cycle water of the steam turbine.
[0013] When using hydrogen fuel as fuel, the multipurpose thermal
power plant system of the present invention includes an oxygen
combustion boiler, a steam turbine, a generator, an oxygen
separator for generating oxygen fed to the oxygen combustion
boiler, a fuel feed apparatus for feeding hydrogen fuel to the
oxygen combustion boiler, a gas heat exchanger for performing heat
exchange between boiler exhaust gas and recirculation boiler
exhaust gas including oxygen, a condensate cooler for cooling
exhaust gas at the exit of the gas heat exchanger with condensate
of the steam turbine, a recirculation system for recirculating
boiler exhaust gas at the exit of the condensate cooler to the
oxygen combustion boiler, an oxygen injection system for feeding
oxygen from the oxygen separator to the recirculation system, a
cooling water-desalination apparatus for producing water by cooling
boiler exhaust gas from the condensate cooler, a fresh water tank
for capturing water generated by the cooling water-desalination
apparatus, and a water feed system for feeding water of the fresh
water tank to the steam turbine system as steam cycle water of the
steam turbine.
[0014] When using fossil fuel composed of carbon as fuel, the
multipurpose thermal power plant system of the present invention
includes an oxygen combustion boiler, a steam turbine, a generator,
an oxygen separator for generating oxygen fed to the oxygen
combustion boiler, a fuel feed apparatus for feeding fossil fuel
composed of carbon to the oxygen combustion boiler, a gas heat
exchanger for performing heat exchange between boiler exhaust gas
and recirculation boiler exhaust gas including oxygen, a condensate
cooler for cooling exhaust gas at the exit of the gas heat
exchanger with condensate of the steam turbine, a recirculation
system for recirculating boiler exhaust gas at the exit of the
condensate cooler to the oxygen combustion boiler, an oxygen
injection system for feeding oxygen from the oxygen separator to
the recirculation system, a carbon dioxide liquefier for obtaining
carbon dioxide by compressing boiler exhaust gas from the
condensate cooler, and a carbon dioxide storage tank for storing
liquefied carbon dioxide obtained by the carbon dioxide
liquefier.
[0015] According to the present invention, in correspondence to the
fuel kind burned by the boiler, from the fuel, not only electric
energy but also water or carbon dioxide can be obtained
simultaneously in large quantities at a low cost by a method
friendly to the natural environment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a block diagram of the multipurpose thermal power
plant system of a first embodiment of the present invention using
fuel like coal including carbon, hydrogen, ash, and moisture as
main components of boiler fuel and a small amount of sulfur and
nitrogen;
[0017] FIG. 2 is a block diagram of the multipurpose thermal power
plant system of a second embodiment of the present invention using
fuel like liquefied natural gas including carbon, hydrogen, and
hydrocarbon as main components of boiler fuel but not including a
small amount of sulfur and nitrogen;
[0018] FIG. 3 is a block diagram of the multipurpose thermal power
plant system of a third embodiment of the present invention using
hydrogen gas fuel including only hydrogen as a main component of
boiler fuel but not including a small amount of sulfur and
nitrogen; and
[0019] FIG. 4 is a block diagram of the multipurpose thermal power
plant system of a fourth embodiment of the present invention using
carbon fuel including only carbon as a main component of boiler
fuel but not including a small amount of sulfur and nitrogen.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Hereinafter, by referring to the accompanying drawings, with
respect to the multipurpose thermal power plant system using the
oxygen combustion boiler, a plurality of embodiments of the present
invention with the fuel of the oxygen combustion boiler changed
will be explained. FIGS. 1 to 4 show embodiments of the
multipurpose thermal power plant system corresponding to four kinds
of fuel. In all the drawings, the same components are given the
same numerals.
Embodiment 1
[0021] FIG. 1 shows a first embodiment of the present invention of
the multipurpose thermal power plant system using fuel like coal
composed of the main components of carbon, hydrogen, ash, and
moisture as fuel of an oxygen combustion boiler 1 including a very
small amount of sulfur and nitrogen. This embodiment is a
multipurpose thermal power plant system for simultaneously
capturing electric power, water, and carbon dioxide.
[0022] The multipurpose thermal power plant system of this
embodiment includes the oxygen combustion boiler 1 for burning coal
and generating steam, a steam turbine 2 driven so as to rotate by
the steam generated by the oxygen combustion boiler 1, an oxygen
combustion boiler steam pipe 4 for carrying steam 51 generated by
the oxygen combustion boiler 1, a generator 3 for converting the
turning force of the steam turbine 2 to electric power, a
condensate pump 61 and a feed water pump 66 for feeding condensate
obtained by condensing the steam for driving to rotate the steam
turbine 2 to water by a condenser 60 to the oxygen combustion
boiler 1, and a low-pressure feed water heater 62 and a
high-pressure feed water heater 67 for heating the condensate by
bleed steam from the steam turbine 2.
[0023] The condensate fed from the condensate pump 60 is partially
branched, is fed to a condensate cooler 12 via a condensate feed
pipe 63, and cools boiler exhaust gas discharged from a gas heat
exchanger 11. The condensate temperature at the exit of the
condenser 60 depends upon the vacuum level of the condenser, though
assuming the vacuum level as 722 mmHg Vac, the saturation
temperature is about 33.1.degree. C. and the condensate can cool
boiler exhaust gas discharged from the gas heat exchanger 11. If
the gas temperature at the exit of the condensate cooler 12 is
lowered, the gas temperature of exhaust gas flowing into a cooling
water-desalination apparatus 15 at the later stage is lowered. The
condensate heated by the condensate cooler 12 flows into a
deaerator 65 via a condensate return pipe 64. The heat captured by
the condensate cooler 12 produces an efficiency improvement effect
for the entire plant. Further, by the condensate cooler 12, the
exhaust gas temperature at the exit of the gas heat exchanger 11 is
lowered, thus the entrance device of a forced fan (FDF) 27 which
will be described later is cooled to an allowable design
temperature or lower.
[0024] The feed water discharged from the deaerator 65 is
pressurized by the feed water pump 66, flows down through the
high-pressure feed water heater 67, and is fed into the oxygen
combustion boiler 1 as feed water from the boiler feed water pipe
5. This feed water is heated again to steam by the oxygen
combustion boiler 1 and is fed to the steam turbine 2.
[0025] Into the oxygen combustion boiler 1, coal fuel is input from
a coal fuel feed apparatus 7 via a fuel feed pipe 9. In the coal
fuel, hydrogen 45, carbon 46, nitrogen 47, and sulfur 48 are
included.
[0026] At the exit of an induction fan (IDF) 35, a part of the
boiler exhaust gas is branched, and the branched boiler exhaust gas
is permitted to flow down through a boiler exhaust gas
recirculation duct 24 via a boiler exhaust gas recirculation damper
81 and recirculate to the oxygen combustion boiler 1. Namely, a
boiler exhaust gas recirculation gas system for returning the exit
gas of the induction fan (IDF) 35 to the entrance of the forced fan
(FDF) 27 is installed and the boiler exhaust gas is recirculated to
the oxygen combustion boiler 1. The residual boiler exhaust gas
flows on the side of a desulfurizer 14.
[0027] Further, in the boiler exhaust gas recirculation duct 24,
oxygen 44 in air from the oxygen separator 6 flows via an oxygen
feed damper 80 at the exit of the oxygen separator and the oxygen
feed pipe 8 and is mixed with boiler recirculation gas. Namely, the
oxygen injection place from the oxygen separator 6 is connected to
the entrance of the forced fan (FDF) 27, thus the oxygen can be
mixed with boiler exhaust gas from the condensate cooler 12. In the
oxygen separator 6, nitrogen 43 in the air is separated from oxygen
44 in the air.
[0028] A mixture of oxygen and boiler recirculation gas flows down
through an entrance duct 26 of the forced fan (FDF) and is sucked
into the forced fan (FDF) 27. The mixed gas including oxygen is
pressurized by the forced fan (FDF) 27, passes through an exit duct
28 of the forced fan (FDF), and enters the gas heat exchanger 11 to
be heated. The mixed gas raised in temperature by the gas heat
exchanger 11 passes through an exit duct 30 of the gas heat
exchanger and is input into the oxygen combustion boiler 1 to burn
coal.
[0029] Oxygen is oxidized in the oxygen combustion boiler 1, so
that the components in the exhaust gas of the oxygen combustion
boiler 1 are mainly composed of carbon dioxide 53, steam 54,
nitrogen oxide 55, and sulfur oxide 56. These boiler exhaust gas
components flow into the denitrification equipment 10 via an exit
exhaust gas duct 31 of the oxygen combustion boiler. In the
denitrification equipment 10, according to the chemical reaction
formulas (1) and (2) indicated below, the nitrogen oxide 55 in the
exhaust gas of the oxygen combustion boiler is decomposed by the
chemical reaction on ammonia, thus exit steam 57 of the
denitrification equipment and exit nitrogen 58 of the
denitrification equipment are produced.
4NO+4NH.sub.3+O.sub.2.fwdarw.4N.sub.2+6H.sub.2O (1)
2NO.sub.2+4NH.sub.3+O.sub.2.fwdarw.3N.sub.2+6H.sub.2O (2)
[0030] Exit boiler exhaust gas of the denitrification equipment 10
flows into the gas heat exchanger 11 via an exit duct 32 of the
denitrification equipment.
[0031] Boiler exhaust gas discharged from an exit duct 33 of the
gas heat exchanger and the condensate cooler 12 flows down through
an entrance duct 34 of the dust collector. The boiler exhaust gas
with dust removed by the dust collector (electric dust collector)
13 is induced and pressurized by the induction fan 35.
[0032] The sulfur oxide 56 in the exit exhaust gas of the oxygen
combustion boiler becomes exit sulfur oxide 59 of the
denitrification equipment without being particularly affected.
Furthermore, it becomes exit sulfur oxide 85 of the gas heat
exchanger, flows down through the condensate cooler 12, the dust
collector 13, and an induction fan (IDF) 35, and enters the
desulfurizer 14 to be desulfurized. Here, the exit sulfur oxide 85
of the gas heat exchanger causes a chemical reaction on calcium
carbonate CaCO.sub.3 49 according to the following chemical
reaction formula (3) and becomes calcium sulfate
CaSO.sub.4.2H.sub.2O and carbon dioxide gas. The carbon dioxide gas
becomes exit carbon dioxide 86 of the desulfurizer together with
exit carbon dioxide 68 of the gas heat exchanger and is captured by
capture 16 of the carbon dioxide liquefier that will be described
later.
SO.sub.2+2H.sub.2O+CaCO.sub.3+0.5O.sub.2.fwdarw.CaSO.sub.4.2H.sub.2O+CO.-
sub.2 (3)
[0033] The boiler exhaust gas components flowing through a
desulfurizer exit duct 36 at the exit of the desulfurizer 14 are
composed of only carbon dioxide, steam, and nitrogen gas.
[0034] The boiler exhaust gas discharged from the desulfurizer 14
is pressurized by a pressurizing fan (BUF) 98 and is sent by the
cooling water-desalination apparatus 15. Non-condensable gas in the
cooling water-desalination apparatus 15 and steam are cooled
simultaneously, thus the moisture in the gas is cooled to the steam
saturation temperature or lower to be captured. To the cooling
water-desalination apparatus 15, the cooling water 19 is fed
through the cooling water feed pipe 18. The cooling water
discharged from the cooling water-desalination apparatus 15 passes
through a cooling water return pipe 20, becomes return cooling
water 21, and comes out. The water separated by the cooling
water-desalination apparatus 15 is pressurized by a desalinated
water take-out pipe 22 and a desalinated water transfer pump 70 and
is fed to a fresh water tank 72 to be stored. The stored fresh
water passes through a feed water desalination apparatus 74 via an
entrance pipe 73 of the feed water desalination apparatus and after
removal of impurities in the fresh water, is fed to the condenser
60 as water to supplement blow water with water-steam cycle water
of the steam turbine 2 or feed water for water-steam cycle water
during continuous operation to be utilized.
[0035] In this embodiment, the exit gas temperature of the
condensate cooler 12 is lowered, thus the gas temperature of
exhaust gas flowing into the cooling water-desalination apparatus
15 at the later stage is lowered, so that without increasing the
amount of cooling feed water to the cooling water-desalination
apparatus 15 and lowering the water temperature, the moisture
amount captured by the cooling water-desalination apparatus 15 can
be increased to three or four times and it is a sufficient amount
of water to supplement blow water with water-steam cycle water of
the steam turbine 2 or feed water for water-steam cycle water
during continuous operation.
[0036] To the coal fuel feed apparatus 7, from a low-temperature
bypass damper 75 of the gas heat exchanger, boiler recirculation
gas including low-temperature oxygen is fed. Furthermore, from an
exit high-temperature damper 76 of the gas heat exchanger, boiler
recirculation gas including high-temperature oxygen is fed to the
coal fuel feed apparatus 7. This gas including coal passes through
the fuel feed pipe 9 and is input to the oxygen combustion boiler
1, thus coal combustion is executed.
[0037] High-purity nitrogen gas 52 discharged from the oxygen
separator and exit nitrogen gas 23 of the carbon oxide liquefier
are returned into the original air.
[0038] At the time of start, the oxygen combustion boiler 1 is
air-burned using starting fuel. To start the oxygen combustion
boiler 1, via an air intake duct 25 and an air intake damper 82,
air is permitted to flow into the forced fan (FDF) 27 through the
entrance duct 26 of the forced fan (FDF). This air is pressurized
by the forced fan (FDF) 27, then passes through the exit duct 28 of
the forced fan (FDF), and enters the gas heat exchanger 11. By the
gas heat exchanger 11, air is heated by boiler exhaust gas, flows
down through the exit duct 30 of the gas heat exchanger, is
conveyed to the oxygen combustion boiler 1 as combustion air, and
burns the starting fuel (for example, gas oil, not drawn). The
boiler exhaust gas discharged from the oxygen combustion boiler 1
passes through the denitrification equipment 10, the gas heat
exchanger 11, the condensate cooler 12, and the dust collector 13,
is sucked in and pressurized by the induction fan (IDF) 35. The
pressurized boiler exhaust gas passes through the desulfurizer 14,
flows down through the desulfurizer exit duct 36 and a chimney
entrance damper 96, enters a chimney 97, and is discharged into the
air.
[0039] After starting, if oxygen combustion is switched, by an
operation of closing the chimney entrance damper 96 by opening an
entrance damper 95 of the cooling water-desalination apparatus, the
boiler exhaust gas is switched to the side of the cooling
water-desalination apparatus. The boiler exhaust gas flows on the
side of the cooling water-desalination apparatus entrance damper 95
and the moisture and carbon dioxide in the boiler exhaust gas are
captured respectively by the cooling water-desalination apparatus
15 and the carbon dioxide liquefier 16 which are apparatuses on the
downstream side. The captured moisture is stored once in the fresh
water tank 72. Further, the captured carbon dioxide is stored once
in a carbon dioxide storage tank 17.
[0040] As mentioned above, this embodiment, using the oxygen
combustion boiler, oxygen separator, fuel feed apparatus, steam
turbine, steam turbine generator, denitrification equipment, gas
heat exchanger, condensate cooler for cooling gas heat exchanger
exit gas by condensate at the exit of the condenser which is a part
of turbine steam cycle water, dust collector, desulfurizer, cooling
water-desalination apparatus, and carbon dioxide liquefier,
utilizing the characteristic that the main components of exhaust
gas of the oxygen combustion boiler after combustion are carbon
dioxide gas and steam, cools and compresses the exhaust gas and
captures simultaneously the moisture and carbon dioxide in the gas.
Furthermore, this embodiment is equipped with a water feed system
for utilizing the moisture captured from the boiler exhaust gas as
cycle water of the steam-water cycle of the steam turbine. The
steam from the oxygen combustion boiler is all used for power
generation and feed of a large amount of steam required by the
water desalination apparatus and carbon dioxide capture apparatus
is never necessary.
[0041] According to this embodiment, in correspondence to the fuel
kind burned by the boiler (coal in this embodiment), from the fuel,
not only electric energy but also water and carbon dioxide can be
obtained simultaneously in large quantities at a low cost by a
method friendly to the natural environment. Namely, from the
exhaust gas system of the oxygen combustion boiler, sulfur oxides,
nitrogen oxides, dust, and carbon dioxide are never discharged into
the atmosphere, so that steam, water, and carbon dioxide for power
generation can be produced simultaneously. Furthermore, the
captured water can be utilized as steam cycle water of the steam
turbine. Further, the oxygen combustion boiler, to output the same
output, compared with a conventional general air combustion boiler,
does not need to suck in nitrogen gas in the air not contributing
to combustion into the boiler furnace, and generation of a nitrogen
oxide produced from nitrogen gas in the air is not caused, so that
an environment improvement effect is obtained. Not only fresh water
generated by water desalination can be reused as steam cycle water
of the steam turbine but also with respect to excessive moisture,
in a region lacking in water resources, practical use as industrial
water and drinking water can be expected.
[0042] Further, in the patent document 1, the boiler exhaust gas
recirculation fan system is used, so that a recirculation fan for
recirculating the boiler exhaust gas is necessary and an increase
in the cost of equipment and an increase in the fan power are
caused. In this embodiment, the induction fan (IDF) 35 and the
forced fan (FDF) 27 are used for recirculation, so that compared
with the case of use of the recirculation fan, an effect of
reducing the cost of equipment and power is obtained.
[0043] Further, in the embodiment aforementioned, the exhaust gas
discharged from the desulfurizer 14 is pressurized by the
pressurizing fan (BUF) 98 and is sent to the cooling
water-desalination apparatus 15, though the necessary total head of
the boiler exhaust gas fed to the cooling water-desalination
apparatus 15 is permitted to impose a burden on the head of the
induction fan, thus the pressurizing fan can be omitted.
Embodiment 2
[0044] FIG. 2 shows a second embodiment of the present invention of
the multipurpose thermal power plant system using fuel like
liquefied natural gas (LNG) composed of the main components of
carbon and hydrogen free of a very small amount of sulfur and
nitrogen as fuel of the oxygen combustion boiler 1. This embodiment
is also a multipurpose thermal power plant system for
simultaneously capturing electric power, water, and carbon dioxide.
For the same portions as those shown in FIG. 1, the explanation
will be omitted.
[0045] In this embodiment, the oxygen combustion boiler 1 burns LNG
fed from a liquefied natural gas (LNG) fuel feed apparatus 77 and
generate steam. Therefore, the oxygen combustion boiler 1 has a
system constitution that from the embodiment shown in FIG. 1, the
denitrification equipment, duct collector, and desulfurizer are
removed.
[0046] To the oxygen combustion boiler 1, from the liquefied
natural gas (LNG) fuel feed apparatus 77, LNG fuel composed of
hydrogen 45 and carbon 46 is input. Further, to the oxygen
combustion boiler 1, mixed gas of the oxygen raised in temperature
by the gas heat exchanger 11 and boiler recirculation gas is input
and the mixed gas burns the LNG fuel. LNG is oxidized in the oxygen
combustion boiler 1, thus the exhaust gas components of the oxygen
combustion boiler 1 are composed of mainly carbon dioxide 53 and
hydrogen 54 in the exhaust gas of the oxygen combustion boiler.
[0047] The boiler exhaust gas passes through the exit exhaust gas
duct 31 of the oxygen combustion boiler and flows down into the gas
heat exchanger 11. The boiler exhaust gas is fed to the condensate
cooler 12 via the exit duct 33 of the exhaust gas heat exchanger
and is cooled by a condensate. If the exit gas temperature of the
condensate cooler 12 is lowered, the gas temperature to the cooling
water-desalination apparatus 15 at the later stage is lowered and a
cooling effect is produced. Further, the condensate heated by the
condensate cooler 12 passes through the condensate return pipe 64
and flows into the deaerator 65. The captured heat produces an
efficiency improvement effect for the entire plant.
[0048] The boiler exhaust gas discharged from the condensate cooler
12 enters the induction fan (IDF) 35. The boiler exhaust gas is
induced and pressurized by the induction fan (IDF) 35, and then is
fed to the cooling water-desalination apparatus 15. The boiler
exhaust gas is cooled by the cooling water-desalination apparatus
15, thus the moisture in the gas is cooled to the steam saturation
temperature or lower and is captured.
[0049] At the time of starting, similarly to Embodiment 1, the
oxygen combustion boiler 1 is air-burned using starting fuel (for
example, gas oil). The air-burned boiler exhaust gas passes through
the gas heat exchanger 11 and the condensate cooler 12 and is
sucked in and pressurized by the induction fan (IDF) 35. The
pressurized boiler exhaust gas flows down through the chimney
entrance damper 96, enters the chimney 97, and is discharged into
the air. After starting, if oxygen combustion is switched, by an
operation of closing the chimney entrance damper 96 by opening the
entrance damper 95 of the cooling water-desalination apparatus, the
boiler exhaust gas is switched to the side of the cooling
water-desalination apparatus.
[0050] The moisture and carbon dioxide in the boiler exhaust gas
are captured respectively by the cooling water-desalination
apparatus 15 and the carbon dioxide liquefier 16 which are
apparatuses on the downstream side. The captured moisture is stored
once in the fresh water tank 72. Further, the captured carbon
dioxide is stored once in the carbon dioxide storage tank 17.
High-purity exit nitrogen gas of the carbon oxide liquefier is
returned into the original air.
[0051] According to this embodiment, similarly to Embodiment 1, in
correspondence to the fuel kind burned by the boiler (liquefied
natural gas (LNG) in this embodiment), from the fuel, not only
electric energy but also water and carbon dioxide can be obtained
simultaneously in large quantities at a low cost by a method
friendly to the natural environment.
[0052] Also in this embodiment, the induction fan (IDF) 35 and the
forced fan (FDF) 27 are used for recirculation, so that compared
with the case of use of the recirculation fan, an effect of
reducing the cost of equipment and power is obtained.
[0053] Further, as fuel of this embodiment, liquefied natural gas
(LNG) is used, so that the pressure in the furnace of the oxygen
combustion boiler generally using a negative pressure design can be
changed to a positive pressure design and in this case, the head of
the induction fan is permitted to impose a burden on the head of
the forced fan (FDF) 27, thus the induction fan (IDF) 35 can be
omitted and it is effective in reducing the cost of equipment.
[0054] Further, similarly to Embodiment 1, the necessary total head
of the boiler exhaust gas fed to the cooling water-desalination
apparatus 15 is permitted to impose a burden on the head of the
induction fan, thus the pressurizing fan can be omitted.
Embodiment 3
[0055] FIG. 3 shows a third embodiment of the present invention of
the multipurpose thermal power plant system using fuel like
hydrogen gas composed of hydrogen free of a very small amount of
sulfur and nitrogen as fuel of the oxygen combustion boiler 1. This
embodiment is a multipurpose thermal power plant system for
simultaneously capturing electric power and water. For the same
portions as those shown in FIG. 1, the explanation will be
omitted.
[0056] In this embodiment, the oxygen combustion boiler 1 burns
hydrogen fed from a hydrogen fuel feed apparatus 78 and generates
steam. Therefore, the oxygen combustion boiler 1 has a system
constitution that from the embodiment shown in FIG. 1, the
denitrification equipment, duct collector, desulfurizer, and carbon
dioxide liquefier are removed.
[0057] To the oxygen combustion boiler 1, from the hydrogen gas
fuel feed apparatus 78, hydrogen 45 for fuel is input from the fuel
feed pipe 9. Further, to the oxygen combustion boiler 1, mixed gas
of the oxygen raised in temperature by the gas heat exchanger 11
and boiler recirculation gas is input and the mixed gas burns the
hydrogen. Hydrogen is oxidized in the oxygen combustion boiler 1,
thus the exhaust gas components of the oxygen combustion boiler 1
are composed of mainly steam 54.
[0058] The boiler exhaust gas passes through the exit exhaust gas
duct 31 of the oxygen combustion boiler and flows down into the gas
heat exchanger 11. The boiler exhaust gas is fed to the condensate
cooler 12 via the exit duct 33 of the exhaust gas heat exchanger
and is cooled by a condensate. If the exit gas temperature of the
condensate cooler 12 is lowered, the gas temperature to the cooling
water-desalination apparatus 15 at the later stage is lowered.
Further, the condensate heated by the condensate cooler 12 passes
through the condensate return pipe 64 and flows into the deaerator
65. The captured heat produces an efficiency improvement effect for
the entire plant.
[0059] The boiler exhaust gas discharged from the condensate cooler
12 enters the induction fan (IDF) 35. The boiler exhaust gas is
induced and pressurized by the induction fan (IDF) 35, and then is
fed to the cooling water-desalination apparatus 15. The boiler
exhaust gas is cooled by the cooling water-desalination apparatus
15, thus the moisture in the gas is cooled to the steam saturation
temperature or lower and is captured.
[0060] At the time of starting, similarly to Embodiment 1, the
oxygen combustion boiler 1 is air-burned using starting fuel (for
example, gas oil). The air-burned boiler exhaust gas passes through
the gas heat exchanger 11 and the condensate cooler 12 and is
sucked in and pressurized by the induction fan (IDF) 35. The
pressurized boiler exhaust gas flows down through the chimney
entrance damper 96, enters the chimney 97, and is discharged into
the air. After starting, if oxygen combustion is switched, by an
operation of closing the chimney entrance damper 96 by opening the
entrance damper 95 of the cooling water-desalination apparatus, the
boiler exhaust gas is switched to the side of the cooling
water-desalination apparatus.
[0061] The moisture in the boiler exhaust gas is captured by the
cooling water-desalination apparatus 15. The captured moisture is
stored once in the fresh water tank 72.
[0062] According to this embodiment, similarly to the other
embodiments, in correspondence to the fuel kind burned by the
boiler (hydrogen gas in this embodiment), from the fuel, not only
electric energy but also water can be obtained simultaneously in
large quantities at a low cost by a method friendly to the natural
environment.
[0063] Further, as fuel of this embodiment, hydrogen gas is used,
so that the pressure in the furnace of the oxygen combustion boiler
generally using a negative pressure design can be changed to a
positive pressure design and in this case, the head of the
induction fan is permitted to impose a burden on the head of the
forced fan (FDF) 27, thus the induction fan (IDF) 35 can be omitted
and it is effective in reducing the cost of equipment.
[0064] Further, similarly to Embodiment 1, the necessary total head
of the boiler exhaust gas fed to the cooling water-desalination
apparatus is permitted to impose a burden on the head of the
induction fan, thus the pressurizing fan can be omitted.
Embodiment 4
[0065] FIG. 4 shows a fourth embodiment of the present invention of
the multipurpose thermal power plant system using fuel like carbon
(char) composed of carbon free of a very small amount of sulfur and
nitrogen as fuel of the oxygen combustion boiler 1. This embodiment
is a multipurpose thermal power plant system for simultaneously
obtaining steam and carbon dioxide. For the same portions as those
shown in FIG. 1, the explanation will be omitted.
[0066] This embodiment burns carbon fed from a carbon fuel feed
apparatus 79 and generates steam. Therefore, this embodiment has a
system constitution that from the embodiment shown in FIG. 1, the
denitrification equipment, duct collector, desulfurizer, and
cooling water-desalination apparatus are removed.
[0067] To the oxygen combustion boiler 1, from the carbon fuel feed
apparatus 79, carbon 46 for fuel is input via the fuel feed pipe 9.
Further, to the oxygen combustion boiler 1, mixed gas of the oxygen
raised in temperature by the gas heat exchanger 11 and boiler
recirculation gas is input and the mixed gas burns the carbon.
Carbon is oxidized in the oxygen combustion boiler 1, thus the
exhaust gas component of the oxygen combustion boiler 1 is carbon
dioxide 53 in the exit exhaust gas of the oxygen combustion
boiler.
[0068] The boiler exhaust gas passes through the exit exhaust gas
duct 31 of the oxygen combustion boiler and flows down into the gas
heat exchanger 11. The boiler exhaust gas is fed to the condensate
cooler 12 via the exit duct 33 of the exhaust gas heat exchanger
and is cooled by a condensate. If the exit gas temperature of the,
condensate cooler 12 is lowered, the gas temperature to the carbon
dioxide liquefier 16 at the later stage is lowered and an effect of
improving the efficiency of liquefying carbon dioxide is produced.
The condensate heated by the condensate cooler 12 passes through
the condensate return pipe 64 and flows into the deaerator 65. The
captured heat produces an efficiency improvement effect for the
entire plant.
[0069] The boiler exhaust gas discharged from the condensate cooler
12 enters the induction fan (IDF) 35. The boiler exhaust gas is
induced and pressurized by the induction fan (IDF) 35 and then is
fed to the carbon dioxide liquefier 16. The boiler exhaust gas
(carbon dioxide gas) is compressed and cooled by the carbon dioxide
liquefier 16, and is thereby liquefied.
[0070] At the time of starting, similarly to Embodiment 1, the
oxygen combustion boiler 1 is air-burned using starting fuel (for
example, gas oil). The air-burned boiler exhaust gas passes through
the gas heat exchanger 11 and the condensate cooler 12 and is
sucked in and pressurized by the induction fan (IDF) 35. The
pressurized boiler exhaust gas flows down through the chimney
entrance damper 96, enters the chimney 97, and is discharged into
the air. After starting, if oxygen combustion is switched, by an
operation of closing the chimney entrance damper 96 by opening the
entrance damper 94 of the carbon dioxide liquefier, the boiler
exhaust gas is switched to the side of the carbon dioxide
liquefier.
[0071] Carbon dioxide in the boiler exhaust gas is captured by the
carbon dioxide liquefier 16 that is an apparatus on the downstream
side. The captured carbon dioxide is stored once in the carbon
dioxide storage tank 17.
[0072] According to this embodiment, similarly to the other
embodiments, in correspondence to the fuel kind burned by the
boiler (carbon (char) in this embodiment), from the fuel, not only
electric energy but also carbon dioxide can be obtained
simultaneously in large quantities at a low cost by a method
friendly to the natural environment.
[0073] Further, as fuel of this embodiment, carbon (char) is used,
so that the pressure in the furnace of the oxygen combustion boiler
generally using a negative pressure design can be changed to a
positive pressure design and in this case, the head of the
induction fan is permitted to impose a burden on the head of the
forced fan (FDF) 27, thus the induction fan (IDF) 35 can be omitted
and it is effective in reducing the cost of equipment.
[0074] Further, similarly to Embodiment 1, the necessary total head
of the boiler exhaust gas fed to the cooling water-desalination
apparatus 15 is permitted to impose a burden on the head of the
induction fan, thus the pressurizing fan can be omitted.
* * * * *