U.S. patent application number 09/963509 was filed with the patent office on 2004-01-08 for combined cycle gas turbine system.
Invention is credited to Hyakutake, Yoshinori, Sugishita, Hideaki, Uematsu, Kazuo.
Application Number | 20040003583 09/963509 |
Document ID | / |
Family ID | 18819142 |
Filed Date | 2004-01-08 |
United States Patent
Application |
20040003583 |
Kind Code |
A1 |
Uematsu, Kazuo ; et
al. |
January 8, 2004 |
COMBINED CYCLE GAS TURBINE SYSTEM
Abstract
Combined cycle gas turbine system is improved to enhance a gas
turbine efficiency and a combined efficiency by effecting
steam-cooling of a combustor transition piece and a turbine blade.
In a combined cycle system comprising; a gas turbine (8) having a
generator (1), a compressor (2), a combustor (3), a blade cooling
air cooler (4) and a turbine (6); a steam turbine (29) having a
high pressure turbine (21), an intermediate pressure turbine (22)
and a low pressure turbine (23); and a waste heat recovery boiler
(9), saturated water of a high pressure pump (27) is partially led
into a demineralizer (118) and a water sprayer (116) for cooling
steam to be supplied into a moving blade (52) and the steam, after
used for the cooling, is recovered into a reheater (20). Outlet
steam of the high pressure turbine (21) is led into a stationary
blade (53) for cooling thereof and the steam is then recovered into
an inlet of the intermediate pressure turbine (22). Also, steam of
an intermediate pressure superheater (16) is led into a combustor
transition piece (54) for cooling thereof and the steam is
recovered into the inlet of the intermediate pressure turbine (22).
Thus, moving blade cooling steam is reduced and the combined
efficiency is enhanced.
Inventors: |
Uematsu, Kazuo; (Takasago,
JP) ; Hyakutake, Yoshinori; (Takasago, JP) ;
Sugishita, Hideaki; (Takasago, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
18819142 |
Appl. No.: |
09/963509 |
Filed: |
September 27, 2001 |
Current U.S.
Class: |
60/39.182 ;
60/806 |
Current CPC
Class: |
F01K 23/106 20130101;
Y02E 20/16 20130101; F05D 2260/2322 20130101; F02C 7/16
20130101 |
Class at
Publication: |
60/39.182 ;
60/806 |
International
Class: |
F02C 006/18 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 2000 |
JP |
2000-345041 |
Claims
What is claimed is:
1. A combined cycle gas turbine system comprising; a steam turbine
having a high pressure turbine, an intermediate pressure turbine
and a low pressure turbine; a condenser for condensing exhaust
steam of the low pressure turbine of the steam turbine; a gland
steam condenser being connected to the condenser; a gas turbine
having a compressor for compressing air, a combustor for combusting
fuel with the air coming from the compressor and a turbine for
expanding a high temperature combustion gas coming from the
combustor for driving a generator; a cooling steam system for
cooling the combustor and a blade of the turbine; and a waste heat
recovery boiler having components of a feed water heater, an
intermediate pressure superheater, a reheater, etc. and being fed
with exhaust gas of the gas turbine so that condensed water coming
from the condenser via the gland steam condenser may be heated and
vaporized via the components of the waste heat recovery boiler for
supplying steam to the high pressure, intermediate pressure and low
pressure turbines, respectively, wherein the cooling steam system
is constructed to comprise; a moving blade cooling system having a
water spray rate control valve for leading a high pressure water
from the feed water heater, a demineralizer being connected to the
water spray rate control valve and a water sprayer being connected
to the demineralizer for spraying the high pressure water into a
passage for leading cooling steam from an outlet of the high
pressure turbine to be supplied into a moving blade of the gas
turbine; a stationary blade cooling system for leading a portion of
the steam from the outlet of the high pressure turbine into a
stationary blade of the gas turbine; and a combustor cooling system
being fed with steam from the intermediate pressure superheater for
cooling a transition piece of the combustor, and steam from the
moving blade cooling system is recovered into the reheater and
steam from the stationary blade cooling system and the combustor
cooling system is recovered into an inlet of the intermediate
pressure turbine.
2. A combined cycle gas turbine system as claimed in claim 1,
wherein a sprayer is provided so that water diverged at an outlet
of the demineralizer may be sprayed into the combustor cooling
system.
3. A combined cycle gas turbine system comprising; a steam turbine
having a high pressure turbine, an intermediate pressure turbine
and a low pressure turbine; a condenser for condensing exhaust
steam of the low pressure turbine of the steam turbine; a gland
steam condenser being connected to the condenser; a gas turbine
having a compressor for compressing air, a combustor for combusting
fuel with the air coming from the compressor and a turbine for
expanding a high temperature combustion gas coming from the
combustor for driving a generator; a cooling steam system for
cooling the combustor and a blade of the turbine; and a waste heat
recovery boiler having components of a feed water heater, an
intermediate pressure superheater, a reheater, etc. and being fed
with exhaust gas of the gas turbine so that condensed water coming
from the condenser via the gland steam condenser may be heated and
vaporized via the components of the waste heat recovery boiler for
supplying steam to the high pressure, intermediate pressure and low
pressure turbines, respectively, wherein the cooling steam system
is constructed to comprise; a moving blade cooling system having a
demineralizer being connected to a downstream side of the condenser
and a water sprayer being connected to the demineralizer for
spraying water diverged from the condensed water into a passage for
leading cooling steam from an outlet of the high pressure turbine
to be supplied into a moving blade of the gas turbine; a stationary
blade cooling system for leading a portion of the steam from the
outlet of the high pressure turbine into a stationary blade of the
gas turbine; and a combustor cooling system being fed with steam
from the intermediate pressure superheater for cooling a transition
piece of the combustor, and steam from the moving blade cooling
system is recovered into the reheater and steam from the stationary
blade cooling system and the combustor cooling system is recovered
into an inlet of the intermediate pressure turbine.
4. A combined cycle gas turbine system as claimed in claim 3,
wherein water at an outlet of the demineralizer is heated at an
economizer provided in the waste heat recovery boiler to be
supplied into the water sprayer.
5. A combined cycle gas turbine system as claimed in claim 4,
wherein a sprayer is provided so that water diverged at an outlet
of the economizer may be sprayed into the combustor cooling
system.
6. A combined cycle gas turbine system as claimed in claim 5,
wherein a sprayer is provided so that water diverged at the outlet
of the economizer may be sprayed into the stationary blade cooling
system.
7. A combined cycle gas turbine system as claimed in any one of
claims 3 to 6, wherein a drain separator is provided downstream of
each water spraying in the moving blade cooling system, the
stationary blade cooling system and the combustor cooling
system.
8. A combined cycle gas turbine system as claimed in claim 6,
wherein a filter is provided downstream of each of the drain
separators provided in the moving blade cooling system, the
stationary blade cooling system and the combustor cooling system.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a combined cycle
gas turbine system and, more particularly, to a combined cycle gas
turbine system in which temperature and flow rate of cooling steam
are efficiently controlled and heating of fuel and cooling of gas
turbine blade cooling air are carried out by steam generated at a
waste heat recovery boiler.
[0003] 2. Description of the Prior Art
[0004] FIG. 10 is a diagram of a steam cooled type combined cycle
gas turbine system in the prior art. In FIG. 10, the prior art
steam cooled gas turbine system is constructed by a gas turbine 8,
a waste heat recovery boiler 9 and a steam turbine 29. In the gas
turbine 8, suction air is taken into a compressor 2 to be
compressed to a predetermined pressure and while the compressed air
is partially used for cooling a gas turbine blade, the most part
thereof is led into a combustor 3 to be mixed with fuel 7 for
generation of a high temperature gas. The high temperature gas
enters a turbine 6 to expand for work and a turbine output after
deduction of a compressor output is converted into an electric
power at a generator 1. On the other hand, outlet steam of a high
pressure turbine 21 flowing through a piping 101 is partially taken
to be supplied into the turbine 6 for cooling the gas turbine blade
via a cooling steam supply piping 101. This steam is heated by
cooling a steam cooled blade 51 and is recovered into an inlet of
an intermediate pressure turbine 22 via a cooling steam recovery
piping 102. Thus, for cooling the gas turbine blade, the air bled
from the compressor 2 and a portion of the outlet steam of the high
pressure turbine 21 are used.
[0005] While outlet air of the compressor 2 is partially used for
blade cooling in the turbine 6, this air, being of a high
temperature, is cooled to a predetermined temperature at a blade
cooling air cooler 4a using a cooling fan 5 and is then used for
the turbine blade cooling. Thus, the air so led from the compressor
2 is once cooled at the blade cooling air cooler 4a using the
cooling fan 5 to be then supplied into the turbine 6.
[0006] In the waste heat recovery boiler 9, outlet steam of a low
pressure turbine 23 is converted into water from steam at a
condenser 25. Then, the water is pressurized at a feed water pump
26 and heated at a feed water heater 10 to become saturated water.
This saturated water is separated into three systems of water. The
first one becomes saturated steam at a low pressure evaporator 11
and becomes superheated steam at a low pressure superheater 15 and
is then supplied to an inlet of the low pressure turbine 23. The
second one is pressurized to a predetermined pressure at an
intermediate pressure pump 28, becomes saturated water at an
intermediate pressure economizer 12, becomes saturated steam at an
intermediate pressure evaporator 14 and becomes superheated steam
at an intermediate pressure superheater 16 and is then supplied to
an inlet of a reheater 20. And the third one is pressurized to a
predetermined pressure at a high pressure pump 27, becomes
saturated water at a first high pressure economizer 13 and a second
high pressure economizer 17, becomes saturated steam at a high
pressure evaporator 18 and becomes superheated steam at a high
pressure superheater 19 and is then led into the high pressure
turbine 21. The mentioned superheated steam enters the high
pressure turbine 21, the intermediate pressure turbine 22 and the
low pressure turbine 23, respectively, to expand for generating an
output and this output is converted into an electric power at a
generator 24.
[0007] With respect to the abovementioned cooling by steam, it is
impossible to use the steam in a quantity in excess of that of the
steam obtainable at the outlet of the high pressure turbine 21.
Hence, in order to secure a spare quantity of the available steam,
it is preferable to reduce the flow rate of the cooling steam to
the extent possible. Also, if the cooling steam is made less in the
quantity, it becomes possible to control the temperature of the
steam, after used for the cooling, with less variation in the
quantity of the cooling steam. Especially, if the temperature of
the cooling steam heated by the cooling is maintained to a
predetermined level, it will not only enhance the reliability and
life of the cooled blade, rotor, pipings, etc. of the gas turbine
but also it will ensure an operation without damaging the enhanced
combined efficiency. In order to reduce the quantity of the cooling
steam, it is necessary to reduce the temperature of the cooling
steam.
[0008] Thus, while the temperature of the cooling steam is
necessary to be maintained lower for enhancing the reliability of
the cooled blade or the like, in the system shown in FIG. 10, the
cooling steam supply temperature is decided by the outlet condition
of the high pressure turbine 21 and it is difficult to further
reduce the cooling steam temperature in this system.
[0009] Also, the air bled from the compressor for cooling the gas
turbine blade is once cooled at the blade cooling air cooler 4a
using the cooling fan 5 to be supplied into the turbine 6, as
mentioned above, and the heat obtained by such cooling is
discharged outside in vain. This causes a reduction in the thermal
efficiency (gas turbine efficiency and combined efficiency) of the
gas turbine and of a combined cycle system using this gas turbine.
Moreover, the fuel 7 is supplied into the combustor 3 without being
heated (preheated).
SUMMARY OF THE INVENTION
[0010] In view of the mentioned problem in the prior art,
therefore, it is an object of the present invention to provide a
steam cooled type combined cycle gas turbine system in which the
system is made such that cooling of a turbine blade is done by
steam partially taken from an outlet of a high pressure turbine and
temperature of this steam is adjusted by cooling water taken from a
waste heat recovery boiler or by water taken from a condenser, a
cooling steam supply system is made such that a moving blade, a
stationary blade and a combustor transition piece are supplied with
steam via their respective separate systems so that the steam
supplied to the stationary blade and the combustor transition piece
may be of a temperature higher than that supplied to the moving
blade to thereby obtain a higher effect of cooling by steam in the
respective steam systems and also preheating of fuel is done to
thereby enhance a combined efficiency.
[0011] In order to achieve the abovementioned object, the present
invention provides means of the following inventions (1) to
(8).
[0012] (1) A combined cycle gas turbine system comprising; a steam
turbine having a high pressure turbine, an intermediate pressure
turbine and a low pressure turbine; a condenser for condensing
exhaust steam of the low pressure turbine of the steam turbine; a
gland steam condenser being connected to the condenser; a gas
turbine having a compressor for compressing air, a combustor for
combusting fuel with the air coming from the compressor and a
turbine for expanding a high temperature combustion gas coming from
the combustor for driving a generator; a cooling steam system for
cooling the combustor and a blade of the turbine; and a waste heat
recovery boiler having components of a feed water heater, an
intermediate pressure superheater, a reheater, etc. and being fed
with exhaust gas of the gas turbine so that condensed water coming
from the condenser via the gland steam condenser may be heated and
vaporized via the components of the waste heat recovery boiler for
supplying steam to the high pressure, intermediate pressure and low
pressure turbines, respectively, wherein the cooling steam system
is constructed to comprise; a moving blade cooling system having a
water spray rate control valve for leading a high pressure water
from the feed water heater, a demineralizer being connected to the
water spray rate control valve and a water sprayer being connected
to the demineralizer for spraying the high pressure water into a
passage for leading cooling steam from an outlet of the high
pressure turbine to be supplied into a moving blade of the gas
turbine; a stationary blade cooling system for leading a portion of
the steam from the outlet of the high pressure turbine into a
stationary blade of the gas turbine; and a combustor cooling system
being fed with steam from the intermediate pressure superheater for
cooling a transition piece of the combustor, and steam from the
moving blade cooling system is recovered into the reheater and
steam from the stationary blade cooling system and the combustor
cooling system is recovered into an inlet of the intermediate
pressure turbine.
[0013] (2) A combined cycle gas turbine system as mentioned in the
invention (1) above, wherein a sprayer is provided so that water
diverged at an outlet of the demineralizer may be sprayed into the
combustor cooling system.
[0014] (3) A combined cycle gas turbine system comprising; a steam
turbine having a high pressure turbine, an intermediate pressure
turbine and a low pressure turbine; a condenser for condensing
exhaust steam of the low pressure turbine of the steam turbine; a
gland steam condenser being connected to the condenser; a gas
turbine having a compressor for compressing air, a combustor for
combusting fuel with the air coming from the compressor and a
turbine for expanding a high temperature combustion gas coming from
the combustor for driving a generator; a cooling steam system for
cooling the combustor and a blade of the turbine; and a waste heat
recovery boiler having components of a feed water heater, an
intermediate pressure superheater, a reheater, etc. and being fed
with exhaust gas of the gas turbine so that condensed water coming
from the condenser via the gland steam condenser may be heated and
vaporized via the components of the waste heat recovery boiler for
supplying steam to the high pressure, intermediate pressure and low
pressure turbines, respectively, wherein the cooling steam system
is constructed to comprise; a moving blade cooling system having a
demineralizer being connected to a downstream side of the condenser
and a water sprayer being connected to the demineralizer for
spraying water diverged from the condensed water into a passage for
leading cooling steam from an outlet of the high pressure turbine
to be supplied into a moving blade of the gas turbine; a stationary
blade cooling system for leading a portion of the steam from the
outlet of the high pressure turbine into a stationary blade of the
gas turbine; and a combustor cooling system being fed with steam
from the intermediate pressure superheater for cooling a transition
piece of the combustor, and steam from the moving blade cooling
system is recovered into the reheater and steam from the stationary
blade cooling system and the combustor cooling system is recovered
into an inlet of the intermediate pressure turbine.
[0015] (4) A combined cycle gas turbine system as mentioned in the
invention (3) above, wherein water at an outlet of the
demineralizer is heated at an economizer provided in the waste heat
recovery boiler to be supplied into the water sprayer.
[0016] (5) A combined cycle gas turbine system as mentioned in the
invention (4) above, wherein a sprayer is provided so that water
diverged at an outlet of the economizer may be sprayed into the
combustor cooling system.
[0017] (6) A combined cycle gas turbine system as mentioned in the
invention (5) above, wherein a sprayer is provided so that water
diverged at the outlet of the economizer may be sprayed into the
stationary blade cooling system.
[0018] (7) A combined cycle gas turbine system as mentioned in any
one of the inventions (3) to (6) above, wherein a drain separator
is provided downstream of each water spraying in the moving blade
cooling system, the stationary blade cooling system and the
combustor cooling system.
[0019] (8) A combined cycle gas turbine system as mentioned in the
invention (6) above, wherein a filter is provided downstream of
each of the drain separators provided in the moving blade cooling
system, the stationary blade cooling system and the combustor
cooling system.
[0020] In the invention (1), the cooling steam system is
constructed to comprise the three systems of the moving blade
cooling system, the stationary blade cooling system and the
combustor cooling system. The stationary blade cooling system is
supplied with a portion of the steam from the outlet of the high
pressure turbine and the combustor cooling system with the steam
from the intermediate pressure superheater, of which temperature is
comparatively high to that of the moving blade cooling steam, to be
used for the respective cooling. Also, the moving blade cooling
system is constructed to comprise the water spray rate control
valve, the demineralizer and the water sprayer so as to be sprayed
with the water taken from the feed water heater via a high pressure
pump. By such construction, the water spray rate is controlled by
the water spray rate control valve and a quick control of the
supply temperature of the moving blade cooling steam becomes
possible. The demineralizer is such one as is usually used for
removing dissolved minerals in the condenser of a supercritical
pressure plant or a nuclear plant and impurities in the water can
be removed by the demineralizer. Also, the gland steam condenser is
provided so as to make use of condensed water of the gland steam
also and thereby a more efficient system can be constructed. By all
these constructions, there is obtained the feature that a quick
reduction in the supply temperature and supply quantity of the
moving blade cooling steam becomes possible. Also, the temperature
of the steam, after used for the cooling, can be controlled with
less variation in the quantity of the cooling steam and thereby a
spare quantity of the available steam can be ensured and the
reliability and life elongation of the cooled blade, rotor and
pipings can be realized.
[0021] In the invention (2), in addition to the construction of the
invention (1), the combustor cooling system is sprayed with the
water from the demineralizer by the water sprayer and thereby, in
addition to the effect of the invention (1), the steam temperature
in the combustor cooling system can be set lower and the cooling
efficiency can be further enhanced.
[0022] In the invention (3), while the construction and effect of
the stationary blade cooling system and the combustor cooling
system are the same as those of the invention (1), the water
spraying into the moving blade cooling system is done by the water
sprayer using the water taken from the condenser via the
demineralizer and this water sprayed is taken from the system that
is independent of the waste heat recovery boiler. Thus, the water
to be sprayed is supplied from the upstream side of the waste heat
recovery boiler, there are mixed less impurities in the cooling
steam, that is, purity of the cooling steam is enhanced, and
capability to prevent oxidation of the pipings or the like is
enhanced. In addition to the above effect, like in the invention
(1), such a demineralizer as is usually used for removing dissolved
minerals in the condenser of a supercritical pressure plant or a
nuclear plant is used and thereby impurities in the water can be
removed. Also, the gland steam condenser is provided so as to make
use of condensed water of the gland steam also and thereby a more
efficient system can be constructed.
[0023] By such construction, there is obtained the feature that a
quicker reduction in the supply temperature and supply quantity of
the moving blade cooling steam becomes possible. Also, the
temperature of the steam, after used for the cooling, can be
controlled with less variation in the quantity of the cooling steam
and thereby a spare quantity of the available steam can be ensured
and the reliability and life elongation of the cooled blade, rotor
and pipings can be realized.
[0024] In the invention (4), the water supply passage to the water
sprayer in the invention (3) enters the waste heat recovery boiler
before the water enters the water sprayer. The water is heated at
the economizer in the waste heat recovery boiler and is sprayed
into the moving blade cooling system. Hence, in addition to the
effect of the invention (3), temperature difference between the
steam and the water to be sprayed is made smaller and influence of
the thermal stress in the pipings or the like can be reduced.
[0025] In the invention (5), in addition to the construction of the
invention (4), the water spraying system for spraying the water
diverged at the outlet of the economizer into the combustor cooling
system is provided. Hence, in addition to the effect of the
invention (4), the temperature of the steam supplied into the
combustor cooling system can be set lower and the cooling of the
combustor can be done more efficiently.
[0026] In the invention (6), in addition to the construction of the
invention (5), the water spraying system for spraying the water
diverged at the outlet of the economizer into the stationary blade
cooling system is also provided. Hence, in addition to the effect
of the invention (5), the temperature of the steam supplied into
the stationary blade cooling system can be set lower and the
cooling of the stationary blade also can be done more
efficiently.
[0027] In the invention (7), the drain separator is provided
downstream of the water sprayer in each of the moving blade,
stationary blade and combustor cooling systems. Thereby, the water
content in the steam is removed and the cooling in the inventions
(3) to (6) can be done more effectively.
[0028] In the invention (8), the filter is provided downstream of
the drain separator in each of the moving blade, stationary blade
and combustor cooling systems of the construction of the invention
(7). Thereby, impurities in the water sprayed from the water
sprayer are removed from the steam and hence, in addition to the
effect of the invention (7), such shortcomings as clogging of the
passages due to the impurities, like scales, in the cooling steam
supplied into the respective cooling systems can be prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a diagram of a combined cycle gas turbine system
of a first embodiment according to the present invention.
[0030] FIG. 2 is a diagram of a combined cycle gas turbine system
of a second embodiment according to the present invention.
[0031] FIG. 3 is a diagram of a combined cycle gas turbine system
of a third embodiment according to the present invention.
[0032] FIG. 4 is a diagram of a combined cycle gas turbine system
of a fourth embodiment according to the present invention.
[0033] FIG. 5 is a diagram of a combined cycle gas turbine system
of a fifth embodiment according to the present invention.
[0034] FIG. 6 is a diagram of a combined cycle gas turbine system
of a sixth embodiment according to the present invention.
[0035] FIG. 7 is a diagram of a combined cycle gas turbine system
of a seventh embodiment according to the present invention.
[0036] FIG. 8 is a diagram of a combined cycle gas turbine system
of an eighth embodiment according to the present invention.
[0037] FIG. 9 is a diagram of a combined cycle gas turbine system
of a ninth embodiment according to the present invention.
[0038] FIG. 10 is a diagram of a combined cycle gas turbine system
in the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Herebelow, embodiments according to the present invention
will be described concretely with reference to figures.
[0040] FIG. 1 is a diagram of a combined cycle gas turbine system
of a first embodiment according to the present invention. In FIG.
1, the combined cycle gas turbine system of the first embodiment is
constructed by a gas turbine 8, a waste heat recovery boiler 9 and
a steam turbine 29. In the gas turbine 8, suction air is taken into
a compressor 2 to be compressed to a predetermined pressure and
while the compressed air is partially used for cooling a gas
turbine blade, the most part thereof is led into a combustor 3 to
be mixed with fuel for generation of a high temperature gas. The
high temperature gas enters a turbine 6 to expand for work and a
turbine output after deduction of a compressor output is converted
into an electric power at a generator 1.
[0041] In the waste heat recovery boiler 9, outlet steam of a low
pressure turbine 23 is converted into water from steam at a
condenser 25. Then, the water is pressurized at a feed water pump
26 and is supplied into a gland steam condenser 250 to be added
with water condensed from steam used for sealing of a gland portion
and becomes a low temperature water. This water is further led into
a feed water heater 10 to be heated to become saturated water. This
saturated water is separated into three systems of water. The first
one becomes saturated steam at a low pressure evaporator 11 and
becomes superheated steam at a low pressure superheater 15 and is
then supplied to an inlet of the low pressure turbine 23. The
second one is pressurized to a predetermined pressure at an
intermediate pressure pump 28, becomes saturated water at an
intermediate pressure economizer 12, becomes saturated steam at an
intermediate pressure evaporator 14 and becomes superheated steam
at an intermediate pressure superheater 16 and is then supplied
into a transition piece of the combustor 3 for cooling thereof, as
will be described later. And the third one is pressurized to a
predetermined pressure at a high pressure pump 27, becomes
saturated water at a first high pressure economizer 13 and a second
high pressure economizer 17, becomes saturated steam at a high
pressure evaporator 18 and becomes superheated steam at a high
pressure superheater 19 and is then led into a high pressure
turbine 21. The mentioned superheated steam enters the high
pressure turbine 21, an intermediate pressure turbine 22 and the
low pressure turbine 23, respectively, to expand for generating an
output and this output is converted into an electric power at a
generator 24.
[0042] In the present embodiment of FIG. 1, the portion
corresponding to the cooled blade 51 in the prior art shown in FIG.
10 is divided into a steam cooled moving blade 52, a steam cooled
stationary blade 53 and a steam cooled combustor transition piece
54. As for the steam cooled moving blade 52, in which the
temperature of the steam, after used for the cooling, is low,
outlet steam of the high pressure turbine 21 is partially extracted
for cooling the steam cooled moving blade via a piping 109 and is
sprayed with water at a water sprayer 116, as will be described
later, to be supplied into the steam cooled moving blade 52 via a
moving blade cooling steam supply piping 103. The steam heated by
cooling the steam cooled moving blade 52 is recovered into a middle
portion of the reheater 20 via a flow regulating valve 154 and a
moving blade cooling steam recovery piping 104.
[0043] Also, a fuel heater 202 is provided and the system is so
made that saturated steam partially extracted from an outlet of the
intermediate pressure economizer 12 is flown through the fuel
heater 202 via a piping 201 for heating fuel 7 and is then supplied
to an inlet of the feed water heater 10 via a piping 203. By this
arrangement, the fuel 7 is heated and the flow rate of the fuel is
reduced. Thus, the gas turbine efficiency and the combined
efficiency are enhanced.
[0044] Also, outlet water of the high pressure pump 27 is partially
taken via a piping 204 to be supplied into a blade cooling air
cooler 4. At the blade cooling air cooler 4, the water is heated by
cooling air taken from the compressor 2 and the cooling air is
cooled. The water is then recovered into an inlet of the high
pressure evaporator 18 via a piping 205. By this arrangement, the
heat as has so far been discharged outside in vain by a cooling fan
is recovered into the waste heat recovery boiler 9 and the combined
efficiency is enhanced.
[0045] Also, a flow regulating valve 115, a demineralizer 118 and a
water sprayer 116 are added for partially extracting outlet water
of the high pressure pump 27 and controlling to spray the water for
cooling the blade cooling steam.
[0046] By this arrangement, the water spray rate is controlled by
the flow regulating valve 115 and the supply temperature of the
moving blade cooling steam becomes adjustable more quickly than in
the prior art. Also, such a demineralizer 118 as is usually used
for removing dissolved minerals in the condenser of a supercritical
pressure plant or a nuclear plant is used and impurities in the
water can be removed.
[0047] Thus, a quicker reduction in the supply temperature and
supply quantity of the moving blade cooling steam becomes possible.
Also, the temperature of the steam, after used for the cooling, can
be controlled with less variation in the quantity of the cooling
steam. Hence, a spare quantity of the available steam is ensured
and the reliability and life elongation of the cooled blade, rotor
and pipings can be ensured.
[0048] Also, the system is so made that cooling steam for cooling
the steam cooled combustor transition piece 54 is taken from outlet
steam of the intermediate pressure superheater 16 and is recovered
into an inlet of the intermediate pressure turbine 22 via a flow
regulating valve 156.
[0049] By this arrangement, the flow rate of the cooling steam
extracted from the outlet of the high pressure turbine 21 via the
piping 109 is reduced and thereby a spare quantity of the available
steam can be ensured.
[0050] Also, as the temperature of the steam cooled stationary
blade 53 may be to some extent higher than that of the moving blade
52, outlet steam of the high pressure turbine 21 is extracted via a
piping 105 without being cooled to be supplied as it is into the
stationary blade 53 for cooling thereof and the steam heated
thereby is recovered into an inlet of the intermediate pressure
turbine 22 via a piping 106.
[0051] By this arrangement, while the temperature of the stationary
blade cooling steam becomes higher than that of the moving blade
cooling steam, there is no reduction in the combined efficiency and
a reduction in the supply quantity of the stationary blade and
moving blade cooling steam becomes possible. Also, the temperature
of the steam, after used for the cooling, can be controlled with
less variation in the quantity of the cooling steam. Thus, a spare
quantity of the available steam is ensured and the reliability and
life elongation of the cooled blade, rotor and pipings can be
ensured.
[0052] Also, as flow regulating valves 153, 154, 155 and 156 are
added and, by opening and closing these valves 153 to 156, the flow
rate of the cooling steam of the moving blade, stationary blade and
combustor transition piece becomes adjustable. Thereby, not only in
the rating time but also in the partial load time, the temperature
of the respective recovery steam can be controlled and there is
obtained the effect to ensure the reliability and life elongation
of the moving and stationary blades, combustor transition piece,
rotor and pipings. If the respective flow regulating valves are
operated to the opening side, the flow rate of the steam supplied
increases and the temperature of the respective recovery steam is
reduced. Also, if the respective flow regulating valves are
operated to the closing side, the flow rate of the steam supplied
is reduced and the temperature of the respective recovery steam is
elevated.
[0053] Thus, according to the combined cycle gas turbine system of
the first embodiment as described above, a quicker reduction in the
supply temperature and supply quantity of the moving blade cooling
steam becomes possible. Also, the temperature of the steam, after
used for the cooling, can be controlled with less variation in the
quantity of the cooling steam. Hence, a spare quantity of the
available steam is ensured and the reliability and life elongation
of the cooled blade, rotor and pipings can be ensured.
[0054] FIG. 2 is a diagram of a combined cycle gas turbine system
of a second embodiment according to the present invention. In the
present second embodiment, as compared with the construction of the
first embodiment shown in FIG. 1, the system is so made that a
water spray system for a combustor transition piece cooling system
is added. As the construction and function of other portions are
the same as those of the first embodiment shown in FIG. 1,
description thereon is omitted and the featured portion will be
described.
[0055] In FIG. 2, while water from the demineralizer 118 is
supplied into the water sprayer 116 to be sprayed into a piping 109
that leads outlet steam of the high pressure turbine 21, the water
from the demineralizer 118 is diverged to be supplied into a water
sprayer 251 via a piping 260 and is sprayed into a combustor
transition piece cooling steam supply piping 107 so as to adjust
the temperature of the cooling steam for cooling the combustor
transition piece 54.
[0056] Thus, when the flow rate of the water taken from the high
pressure pump 27 is controlled by the flow regulating valve 115,
the spray rate of the water sprayers 116 and 251 can be adjusted at
the same time and the temperature of the steam for cooling the
steam cooled moving blade 52 and the steam cooled combustor
transition piece 54 can be appropriately controlled.
[0057] In the present second embodiment, like in the first
embodiment, a quicker reduction in the supply temperature and
supply quantity of the moving blade cooling steam becomes possible.
Also, the temperature of the steam, after used for the cooling, can
be controlled with less variation in the quantity of the cooling
steam. Hence, a spare quantity of the available steam is ensured
and the reliability and life elongation of the cooled blade, rotor
and pipings can be ensured. Moreover, by providing the water
sprayer 251, the cooling of the steam cooled combustor transition
piece 54 can be controlled appropriately, as described above.
[0058] FIG. 3 is a diagram of a combined cycle gas turbine system
of a third embodiment according to the present invention. In the
present third embodiment, as compared with the first embodiment
shown in FIG. 1, the system is so made that the water supply system
for the water sprayer 116 is made independent of the waste heat
recovery boiler 9 and a drain separator 114 is provided downstream
of the water sprayer 116. It is to be noted that the drain
separator 114 may not be necessarily provided. As the construction
and function of other portions are the same as those of the first
embodiment shown in FIG. 1, description thereon is omitted and the
featured portion will be described.
[0059] While, in the construction of FIG. 1, the water taken from
the high pressure pump 27 is supplied into the water sprayer 116
via the flow regulating valve 115 and the demineralizer 118, in the
third embodiment shown in FIG. 3, water condensed at the condenser
25 is partially taken by a feed water pump 252 to be led into the
demineralizer 118 and then into the water sprayer 116, provided at
the same position as in FIG. 1, via a piping 261. Thus, the water
supply system for the water sprayer 116 is made independent of the
waste heat recovery boiler 9 and the water therefor is supplied
from the condenser 25 of the turbine.
[0060] In the present third embodiment also, like in the first
embodiment, a quicker reduction in the supply temperature and
supply quantity of the moving blade cooling steam becomes possible.
Also, the temperature of the steam, after used for the cooling, can
be controlled with less variation in the quantity of the cooling
steam. Hence, a spare quantity of the available steam is ensured
and the reliability and life elongation of the cooled blade, rotor
and pipings can be ensured. Moreover, by taking the water from the
condenser 25, impurities mixed in the water flowing in the pipings
or the like can be reduced. Thereby, purity of the cooling steam is
enhanced and oxidation of the pipings or the like can be
prevented.
[0061] FIG. 4 is a diagram of a combined cycle gas turbine system
of a fourth embodiment according to the present invention. In the
present fourth embodiment, as compared with the third embodiment
shown in FIG. 3, while the construction to make the water supply
system for the water sprayer 116 independent of the waste heat
recovery boiler 9 is the same, water to be supplied into the water
sprayer 116 is flown through an economizer 253 for adjustment of
the temperature. As the construction and function of other portions
are the same as those of the third embodiment shown in FIG. 3,
description thereon is omitted and the featured portion will be
described.
[0062] While, in the construction of FIG. 1, the water taken from
the high pressure pump 27 is supplied into the water sprayer 116
via the flow regulating valve 115 and the demineralizer 118, in the
fourth embodiment shown in FIG. 4, like in the example of FIG. 3,
water condensed at the condenser 25 is partially taken by the feed
water pump 252 to be led into the demineralizer 118. In the present
fourth embodiment, the water supplied into the demineralizer 118 is
further led into the economizer 253, that is provided in the waste
heat recovery boiler 9, via a piping 262 for adjustment of the
temperature of the water and is then supplied into the water
sprayer 116, that is provided at the same position as in FIG. 1.
Thus, the water for the water sprayer 116 is supplied from the
condenser 25 of the turbine, not from, and independently of, the
waste heat recovery boiler 9.
[0063] In the present fourth embodiment also, like in the third
embodiment, a quicker reduction in the supply temperature and
supply quantity of the moving blade cooling steam becomes possible.
Also, the temperature of the steam, after used for the cooling, can
be controlled with less variation in the quantity of the cooling
steam. Hence, a spare quantity of the available steam is ensured
and the reliability and life elongation of the cooled blade, rotor
and pipings can be ensured. Moreover, by taking the water from the
condenser 25, impurities mixed in the water flowing in the pipings
or the like can be reduced. Thereby, purity of the cooling steam is
enhanced and oxidation of the pipings or the like can be prevented.
Also, as the water for the water sprayer 116 is supplied
independently of the waste heat recovery boiler 9 but the
temperature of the water is adjusted, or elevated, at the
economizer 253 provided in the waste heat recovery boiler 9,
temperature difference between the steam and the cold water at the
time of mixing by the water spraying is made smaller and thermal
stress caused at the time of the mixing can be suppressed.
[0064] FIG. 5 is a diagram of a combined cycle gas turbine system
of a fifth embodiment according to the present invention. In the
present fifth embodiment, as compared with the fourth embodiment
shown in FIG. 4, a water spray system and a drain separator both in
the combustor transition piece cooling system are added. As the
construction and function of other portions are the same as those
of the fourth embodiment shown in FIG. 4, description thereon is
omitted and the featured portion will be described.
[0065] In FIG. 5, water condensed at the condenser 25 is partially
taken by the feed water pump 252 to be led into the demineralizer
118 and is further led into the economizer 253, provided in the
waste heat recovery boiler 9, via the piping 262 for adjustment
(elevation) of the temperature to be then supplied into the water
sprayer 116 provided at the same position as in FIG. 1. Thus, the
water for the water sprayer 116 is taken from the condenser 25 of
the turbine, not from, and independently of, the waste heat
recovery boiler 9. This construction as sofar described is the same
as that of the fourth embodiment of FIG. 4.
[0066] Furthermore, in the fifth embodiment, the water at an inlet
of the water sprayer 116 is diverged to flow into a water sprayer
254 via a piping 263. At the water sprayer 254, the water is
sprayed into the combustor transition piece cooling steam supply
piping 107. A drain separator 114 is provided downstream of the
water sprayer 254 to thereby completely remove water content of the
steam and then the steam is supplied into the steam cooled
combustor transition piece 54 for cooling thereof.
[0067] In the present fifth embodiment also, like in the fourth
embodiment, a quicker reduction in the supply temperature and
supply quantity of the moving blade cooling steam becomes possible.
Also, the temperature of the steam, after used for the cooling, can
be controlled with less variation in the quantity of the cooling
steam. Hence, a spare quantity of the available steam is ensured
and the reliability and life elongation of the cooled blade, rotor
and pipings can be ensured. Moreover, by taking the water from the
condenser 25, impurities in the water can be reduced to thereby
prevent oxidation of the pipings or the like. Also, as the water
for the water sprayer 116 is supplied independently of the waste
heat recovery boiler 9 but the temperature of the water is
adjusted, or elevated, at the economizer 253 provided in the waste
heat recovery boiler 9, temperature difference between the steam
and the cold water at the time of mixing by the water spraying is
made smaller and thermal stress caused at the time of the mixing
can be suppressed. Furthermore, the temperature of the cooling
steam for the combustor transition piece is adjusted to be reduced
by the water sprayer 254 and the water content of this steam is
removed by the drain separator 114. Hence, the cooling effect of
the combustor transition piece is further enhanced.
[0068] FIG. 6 is a diagram of a combined cycle gas turbine system
of a sixth embodiment according to the present invention. In the
present sixth embodiment, as compared with the fifth embodiment
shown in FIG. 5, a water sprayer and a drain separator are added
also to the steam cooled stationary blade cooling system. As the
construction and function of other portions are the same as those
of the fifth embodiment shown in FIG. 5, description thereon is
omitted and the featured portion will be described.
[0069] In FIG. 6, water condensed at the condenser 25 is partially
taken by the feed water pump 252 to be led into the demineralizer
118 and is further led into the economizer 253, provided in the
waste heat recovery boiler 9, via the piping 262 for adjustment
(elevation) of the temperature to be then supplied into the water
sprayer 116 provided at the same position as in FIG. 1. Thus, the
water for the water sprayer 116 is taken from the condenser 25 of
the turbine, not from, and independently of, the waste heat
recovery boiler 9. Further, the water at an inlet of the water
sprayer 116 is diverged to flow into the water sprayer 254 via the
piping 263. At the water sprayer 254, the water is sprayed into the
combustor transition piece cooling steam supply piping 107. The
drain separator 114 is provided downstream of the water sprayer 254
to thereby completely remove water content of the steam and then
the steam is supplied into the steam cooled combustor transition
piece 54 for cooling thereof.
[0070] While the construction described above is the same as that
of the fifth embodiment shown in FIG. 5, in the present sixth
embodiment, the construction is so made that the water in the
piping 263 is diverged to flow into a water sprayer 255 via a
piping 264 to be sprayed into the stationary blade cooling steam
supply piping 105. Also, a drain separator 114 is provided
downstream of the water sprayer 255 to thereby remove water content
of the steam and then the steam is supplied into the steam cooled
stationary blade 53 for cooling thereof.
[0071] In the present sixth embodiment also, like in the fifth
embodiment, a quicker reduction in the supply temperature and
supply quantity of the moving blade cooling steam becomes possible.
Also, the temperature of the steam, after used for the cooling, can
be controlled with less variation in the quantity of the cooling
steam. Hence, a spare quantity of the available steam is ensured
and the reliability and life elongation of the cooled blade, rotor
and pipings can be ensured. Moreover, by taking the water from the
condenser 25, impurities in the water can be reduced to thereby
prevent oxidation of the pipings or the like. Also, as the water
for the water sprayer 116 is supplied independently of the waste
heat recovery boiler 9 but the temperature of the water is
adjusted, or elevated, at the economizer 253 provided in the waste
heat recovery boiler 9, temperature difference between the steam
and the cold water at the time of mixing by the water spraying is
made smaller and thermal stress caused at the time of the mixing
can be suppressed.
[0072] Furthermore, the temperature of the cooling steam for the
combustor transition piece is adjusted to be reduced by the water
sprayer 254 and the water content of this steam is removed by the
drain separator 114. Hence, the cooling effect of the combustor
transition piece is further enhanced. In addition to this effect,
as the water in the piping 264 is sprayed into the stationary blade
cooling steam by the water sprayer 255 and the water content of the
cooling steam is removed by the drain separator 114, the
temperature of the cooling steam is reduced and the cooling effect
of the steam cooled stationary blade can be further enhanced.
[0073] FIG. 7 is a diagram of a combined cycle gas turbine system
of a seventh embodiment according to the present invention. In the
present seventh embodiment, as compared with the sixth embodiment
shown in FIG. 6, a filter is provided downstream of each of the
three drain separators 114. As the construction and function of
other portions are the same as those of the sixth embodiment shown
in FIG. 6, description thereon is omitted and the featured portion
will be described.
[0074] In FIG. 7, water condensed at the condenser 25 is partially
taken by the feed water pump 252 to be led into the demineralizer
118 and is further led into the economizer 253, provided in the
waste heat recovery boiler 9, via the piping 262 for adjustment
(elevation) of the temperature to be then supplied into the water
sprayer 116 provided at the same position as in FIG. 1. Thus, the
water for the water sprayer 116 is taken from the condenser 25 of
the turbine, not from, and independently of, the waste heat
recovery boiler 9. The steam in the piping 109 is sprayed with the
water by the water sprayer 116 and water content of this steam is
removed at the drain separator 114 and then the steam is supplied
into the steam cooled moving blade 52 for cooling thereof via a
filter 256, as will be described below.
[0075] Further, the water at the inlet of the water sprayer 116 is
diverged to flow into the water sprayer 254 via the piping 263. At
the water sprayer 254, the water is sprayed into the combustor
transition piece cooling steam supply piping 107. Water content in
the steam sprayed with the water is removed at the drain separator
114 provided downstream of the water sprayer 254 and the steam is
supplied into the steam cooled combustor transition piece for
cooling thereof via a filter 257, as will be described below.
[0076] Also, the water in the piping 263 is diverged to flow into
the water sprayer 255 via the piping 264 to be sprayed into the
stationary blade cooling steam supply piping 105. Water content in
the steam sprayed with the water is removed at the drain separator
114 provided downstream of the water sprayer 255 and then the steam
is supplied into the stationary blade for cooling thereof via a
filter 258, as will be described below.
[0077] The construction and function described above are the same
as those of the sixth embodiment shown in FIG. 6 except the
portions of the filters 256 to 258. In the present seventh
embodiment, drain of the steam sprayed with the water is removed at
the drain separators 114 provided at the three places and
impurities of such sizes as cause clogging of the steam pipings are
prevented by the filters 256 to 258 from coming into the portions
to be cooled. The filters 256 to 258 are of the mesh of about 50 to
1000.mu..
[0078] In the present seventh embodiment also, like in the sixth
embodiment, a quicker reduction in the supply temperature and
supply quantity of the moving blade cooling steam becomes possible.
Also, the temperature of the steam, after used for the cooling, can
be controlled with less variation in the quantity of the cooling
steam. Hence, a spare quantity of the available steam is ensured
and the reliability and life elongation of the cooled blade, rotor
and pipings can be ensured. Moreover, by taking the water from the
condenser 25, impurities in the water can be reduced to thereby
prevent oxidation of the pipings or the like. Also, as the water
for the water sprayer 116 is supplied independently of the waste
heat recovery boiler 9 but the temperature of the water is
adjusted, or elevated, at the economizer 253 provided in the waste
heat recovery boiler 9, temperature difference between the steam
and the cold water at the time of mixing by the water spraying is
made smaller and thermal stress caused at the time of the mixing
can be suppressed.
[0079] Furthermore, the temperature of the cooling steam for the
combustor transition piece is adjusted to be reduced by the water
sprayer 254 and the water content of this steam is removed by the
drain separator 114. Hence, the cooling effect of the combustor
transition piece is further enhanced. In addition to this effect,
as the water in the piping 264 is sprayed into the stationary blade
cooling steam by the water sprayer 255 and the water content of the
cooling steam is removed by the drain separator 114, the
temperature of the cooling steam is reduced and the cooling effect
of the steam cooled stationary blade can be further enhanced.
[0080] Also, by providing the filters 256 to 258 downstream of the
drain separators 114, impurities in the steam are removed and hence
the problem to cause the clogging of the pipings is solved and
reliability of the cooling is remarkably enhanced.
[0081] FIG. 8 is a diagram of a combined cycle gas turbine system
of an eighth embodiment according to the present invention. In the
present eighth embodiment, as compared with the first embodiment
shown in FIG. 1, the steam, after used for the cooling of the steam
cooled stationary blade 53 and the combustor transition piece 54,
is recovered not into the intermediate pressure turbine 22 but into
the reheater 20. That is, the construction is made such that the
three steams after used for the cooling of the steam cooled moving
blade 52, the stationary blade 53 and the combustor transition
piece 54 are joined together to be recovered into the reheater 20.
The construction of other portions is the same as that of the first
embodiment shown in FIG. 1 and description thereon is omitted.
[0082] As the steam recovered into the reheater 20 is finally led
into the intermediate pressure turbine 22, the mentioned three
steams are in any way mixed before they enter the intermediate
pressure turbine 22. If suppression of the pressure loss in the
reheater 20 is considered, the mentioned steams are not necessarily
recovered into the reheater 20, but in the present eighth
embodiment, all the three steams are first led into the reheater 20
to be mixed there in view of the relation of the arrangement of the
moving blade, the stationary blade and the combustor as well as of
the reheater 20 and the intermediate pressure turbine 22. Thus, the
temperature of the steam is made uniform in the pipings from the
reheater 20 to the intermediate pressure turbine 22 and there the
high temperature piping portions can be reduced and troubles caused
by the non-uniform temperature can be prevented.
[0083] FIG. 9 is a diagram of a combined cycle gas turbine system
of a ninth embodiment according to the present invention. While, in
the first embodiment shown in FIG. 1, the steam, after used for the
cooling of the steam cooled moving blade 52, is recovered into the
reheater 20 via the flow regulating valve 154, in the present ninth
embodiment, the construction is made such that the steam, after
used for the cooling of the moving blade, may be recovered either
into the intermediate pressure turbine 22 or into the reheater 20
via a three way valve 260. The construction of other portions is
the same as that of the first embodiment shown in FIG. 1. In the
present ninth embodiment also, by controlling the three way valve
260, the three steams used for the cooling of the steam cooled
moving blade 52, the stationary blade 53 and the combustor
transition piece 54, respectively, are mixed appropriately and can
be supplied into the intermediate pressure turbine 22 and the same
effect as in the abovementioned eighth embodiment can be
obtained.
[0084] It is to be noted as a matter of course that the
constructions shown in FIGS. 8 and 9 to mix the three steams used
for the cooling of the moving blade, the stationary blade and the
combustor transition piece to be supplied into the reheater 20 can
be also applied to the systems of the second to the seventh
embodiments shown in FIGS. 2 to 7.
[0085] While the preferred forms of the present invention have been
described, it is to be understood that the invention is not limited
to the particular constructions and arrangements herein illustrated
and described but embraces such modified forms thereof as come
within the scope of the appended claims.
* * * * *