U.S. patent application number 12/003990 was filed with the patent office on 2009-11-19 for gas turbine unit and its cooling method.
This patent application is currently assigned to HITACHI, LTD. Invention is credited to Satoshi Kondo, Shinya Marushima, Masami Noda, Kazunori Yamanaka.
Application Number | 20090282837 12/003990 |
Document ID | / |
Family ID | 14237235 |
Filed Date | 2009-11-19 |
United States Patent
Application |
20090282837 |
Kind Code |
A1 |
Yamanaka; Kazunori ; et
al. |
November 19, 2009 |
Gas turbine unit and its cooling method
Abstract
It is the object of the present invention to feed cooling air
suitable for cooling the high-temperature part of the gas turbine.
The present invention comprises a compressor, a combustor, and a
turbine. Further, a turbine-cooling system to feed the gas from the
compressor to the turbine is provided, and the turbine-cooling
system comprises a heat exchanger to cool the gas compressed by the
compressor, and a means for separating liquid from the gas cooled
by the heat exchanger. Thus, according to the present invention, it
becomes possible to feed cooling air suitable for cooling the
high-temperature part of the gas turbine and to achieve higher
reliability of the gas turbine unit.
Inventors: |
Yamanaka; Kazunori;
(Hitachi, JP) ; Noda; Masami; (Hitachinaka,
JP) ; Marushima; Shinya; (Hitachinaka, JP) ;
Kondo; Satoshi; (Hitachinaka, JP) |
Correspondence
Address: |
MCDERMOTT WILL & EMERY LLP
600 13TH STREET, N.W.
WASHINGTON
DC
20005-3096
US
|
Assignee: |
HITACHI, LTD
Tokyo
JP
|
Family ID: |
14237235 |
Appl. No.: |
12/003990 |
Filed: |
January 4, 2008 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10938511 |
Sep 13, 2004 |
|
|
|
12003990 |
|
|
|
|
09623273 |
Oct 1, 2001 |
6792762 |
|
|
PCT/JP1999/006256 |
Nov 10, 1999 |
|
|
|
10938511 |
|
|
|
|
Current U.S.
Class: |
60/785 ;
60/39.092 |
Current CPC
Class: |
F02C 7/185 20130101 |
Class at
Publication: |
60/785 ;
60/39.092 |
International
Class: |
F02C 6/04 20060101
F02C006/04; F02G 3/00 20060101 F02G003/00 |
Claims
1-12. (canceled)
13. A gas turbine unit comprising a compressor to compress and
discharge gas, a combustor which the gas compressed by the
compressor is fed to, and a turbine to be driven by the combustion
gas of the combustor; wherein said gas turbine unit has a
turbine-cooling system to feed the gas from said compressor to the
turbine, said turbine-cooling system comprising a heat exchanger to
cool the gas compressed by said compressor and a means to measure
the temperature of the gas cooled by the heat exchanger.
14. A gas turbine unit comprising a compressor to compress and
discharge gas, a combustor which the gas compressed by the
compressor is fed to, and a turbine to be driven by the combustion
gas of the combustor; wherein said gas turbine unit has a
turbine-cooling system to feed the gas from said compressor to the
turbine, said turbine-cooling system comprising a heat exchanger to
cool the gas compressed by said compressor, a means to measure the
temperature of the gas cooled by the heat exchanger, and a means
for controlling the supply of refrigerant to said heat exchanger in
accordance with the temperature measured.
15. A gas turbine unit comprising a first compressor to compress
and discharge gas, a combustor which the gas compressed by the
first compressor is fed to, and a turbine to be driven by the
combustion gas of the combustor; wherein said gas turbine unit has
a turbine-cooling system to feed the gas from said first compressor
to the turbine, said turbine-cooling system comprising a heat
exchanger to cool the gas compressed by said first compressor, a
means to measure the temperature of the gas cooled by the heat
exchanger, a means for controlling the supply of refrigerant to
said heat exchanger in accordance with the temperature measured, a
liquid-separating means for separating liquid from the gas cooled
by the heat exchanger, a first dust-collecting means for separating
dust, etc. from the gas having passed through the liquid-separating
means, a second compressor to raise the pressure of the gas having
passed through the dust-collecting means to a desired level, and a
second dust-collecting means for separating dust, etc. from the gas
whose pressure has been raised by the second compressor, said
second dust-collecting means being at least two filters disposed in
parallel in the cooling system of the turbine.
16. A gas turbine unit comprising a first compressor to compress
and discharge gas, a combustor which the gas compressed by the
first compressor is fed to, and a turbine to be driven by the
combustion gas of the combustor; wherein said gas turbine unit has
a turbine-cooling system to feed the gas from said first compressor
to the turbine, said turbine-cooling system comprising a heat
exchanger to cool the gas compressed by said first compressor, a
dust-collecting means for separating dust, etc. from the gas cooled
by the heat exchanger, and a second compressor to raise the
pressure of the gas having passed through the dust-collecting means
to a desired level, said dust-collecting means being at least two
filters disposed in parallel in the cooling system of the
turbine.
17. A gas turbine unit comprising a first compressor to compress
and discharge gas, a combustor which the gas compressed by the
first compressor is fed to, and a turbine to be driven by the
combustion gas of the combustor; wherein said gas turbine unit has
a turbine-cooling system to feed the gas from said first compressor
to the turbine, said turbine-cooling system comprising a heat
exchanger to cool the gas compressed by said first compressor, a
dust-collecting means for separating dust, etc. from the gas cooled
by the heat exchanger, and a second compressor to raise the
pressure of the gas having passed through the dust-collecting means
to a desired level, said dust-collecting means being at least two
filters disposed in parallel in the cooling system of the turbine,
a pressure detector being provided to detect the difference between
the pressures before and after the filter, and passage
opening-and-closing means being disposed above and below the
cooling system of the filter to each control the flow of the air
into the filter.
18. A gas turbine unit comprising a first compressor to compress
and discharge gas, a combustor which the gas compressed by the
first compressor is fed to, and a turbine to be driven by the
combustion gas of the combustor; wherein said gas turbine unit has
a turbine-cooling system to feed the gas from said first compressor
to the turbine, said turbine-cooling system comprising a heat
exchanger to cool the gas compressed by said first compressor, a
liquid-separating means for separating liquid from the gas cooled
by the heat exchanger, a first dust-collecting means for separating
dust, etc. form the gas having passed through the liquid-separating
means, a second compressor to raise the pressure of the gas having
passed through the first dust-collecting means to desired level,
and a second dust-collecting means for separating dust, etc. from
the gas whose pressure has been raised by the second compressor,
said first dust-collecting means being at least two filters
disposed in parallel in the cooling system of the turbine.
19-20. (canceled)
21. A gas turbine unit comprising a first compressor to compress
and discharge gas, a combustor which the gas compressed by the
first compressor is fed to, and a turbine to be driven by the
combustion gas of the combustor; wherein said gas turbine unit has
a turbine-cooling system to feed the gas from said first compressor
to the turbine, said turbine-cooling system comprising a heat
exchanger to cool the gas compressed by said first compressor, a
dust-collecting means for separating dust, etc. from the gas cooled
by the heat exchanger, a second compressor to raise the pressure of
the gas having passed through said dust-collecting means to a
desired level, and a separating means for separating liquid and
dust, etc. from the gas whose pressure has been raised by the
second compressor.
22. A gas turbine unit comprising a first compressor to compress
and discharge gas, a combustor which the gas compressed by the
first compressor is fed to, and a turbine to be driven by the
combustion gas of the combustor; wherein said gas turbine unit has
a turbine-cooling system to feed the gas from said first compressor
to the turbine, said turbine-cooling system comprising a heat
exchanger to cool the gas compressed by said first compressor, a
dust-collecting means for separating dust, etc. from the gas cooled
by the heat exchanger, a separating means for separating liquid and
dust, etc. from the gas having passed through said dust-collecting
means, and a second compressor to raise the pressure of the gas
having passed through the separating means to a desired level.
23-27. (canceled)
28. A gas-turbine cooling method for a gas turbine unit comprising
a compressor to compress and discharge gas, a combustor which the
gas compressed by the compressor is fed to, and a turbine to be
driven by the combustion gas of the combustor; said cooling method
includes a first step to cool the gas compressed by said
compressor, a second step to separate dust, etc. form the gas
cooled, a third step to raise the pressure of the separated gas to
a desired level, a fourth step to cool the turbine by feeding the
gas whose pressure has been raised to the turbine, and a step,
either between said second and third steps or between third and
fourth steps, to separate liquid and dust, etc. from the gas.
Description
TECHNICAL FIELD
[0001] The present invention relates to a gas turbine unit and a
gas-turbine cooling method.
BACKGROUND ART
[0002] It is required to increase the capacity and the efficiency
of gas-turbine power-generating equipment to meet the
ever-increasing demand of electric power and address the problem of
the warming up of the earth. In the case of gas-turbine
power-generating equipment, in particular, wherein air compressed
by a compressor is fed to a combustor, fuel is fed to the combustor
to be burned, and the combustion gas drives a gas turbine, its
capacity and efficiency can be increased by raising the combustion
temperature.
[0003] However, the gas turbine exposed to and driven by combustion
gas of high temperature may be damaged, if not cooled, and such
damage may lead to a serious accident of the gas-turbine
power-generating equipment. Therefore, in the gas-turbine
power-generating equipment using the high-temperature combustion
gas, the high-temperature part of the gas turbine is cooled with
compressed air or steam.
[0004] Besides, the efficiency of gas-turbine power-generating
equipment can be increased by collecting heat from the refrigerant
after it cools the high-temperature part of the gas turbine. On the
other hand, it is desirable to reduce the flow rate of the
refrigerant as low as permissible.
[0005] The configuration of the cooling holes to cool the
high-temperature part of the gas turbine is complex for higher
cooling efficiency. Accordingly, if dust, etc. disturb the smooth
flow of refrigerant or cooling holes are clogged with dust, etc.,
the cooling efficiency decreases and the gas turbine may be
damaged. Therefore, the gas turbine requires highly purified
refrigerant. Besides, refrigerant for cooling the high-temperature
part of the gas turbine is required to be highly purified so that
the refrigerant can flow smoothly through the complex cooling
holes, its flow rate can be reduced as low as permissible, and the
efficiency of the gas-turbine power-generating equipment can be
increased.
[0006] For example, Japanese Unexamined Patent Application No.
54-82518 disclosed a configuration of air-cooled gas turbine
wherein air discharged from a compressor is cooled by a heat
exchanger, the pressure of the air is raised by a booster
compressor, and the air is fed to the high-temperature part of the
gas turbine to cool the part and collected to a combustor.
[0007] Japanese Unexamined Patent Applications Nos. 2-264127,
2-267326, 7-189740, and 7-317562 disclosed technique for cooling
the high-temperature part of the gas turbine.
[0008] In the case of the above air-cooled gas turbine, such
problems are not addressed as the generation of mist due to the
cooling of air by the heat exchanger, the damage of the booster
compressor due to alien substances in cooling air, the decrease of
the cooling efficiency and the damage to the turbine due to the
clogging of cooling holes with alien substances in cooling air, and
so on.
[0009] For example, if cooling air contains alien substances such
as dust, the cooling holes, of which the configuration is complex
for high cooling efficiency, may get clogged with such alien
substances, reducing the flow rate of the refrigerant, and the gas
turbine may be damaged.
[0010] The object of the present invention is to provide a gas
turbine unit and a gas-turbine cooling method capable of feeding
cooling air suitable for cooling the high-temperature part of the
gas turbine.
DISCLOSURE OF THE INVENTION
[0011] The gas turbine unit of the present invention comprises a
compressor to compress and discharge gas, a combustor which the gas
compressed by the compressor is fed to, and a turbine to be driven
by the combustion gas of the combustor.
[0012] Further, primarily, its feature is that the gas turbine unit
of the present invention has a turbine-cooling system to feed the
gas from the compressor to the turbine. The turbine-cooling system
comprises a heat exchanger to cool the gas compressed by the
compressor and a means for separating liquid from the gas cooled by
the heat exchanger.
[0013] The gas-turbine cooling method of the present invention for
cooling a gas-turbine unit, which comprises a compressor to
compress and discharge gas, a combustor which the gas compressed by
the compressor is fed to, and a turbine to be driven by the
combustion gas of the combustor, includes the process of feeding
the gas from compressor to the turbine to cool it. The
turbine-cooling process comprises the steps of cooling the gas
compressed by the compressor and separating liquid from the cooled
gas.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a system diagram of a cooling system of the
high-temperature part of a gas turbine in accordance with the
present invention.
[0015] FIG. 2 is a system diagram of a cooling system of the
high-temperature part of a gas turbine in accordance with the
present invention.
[0016] FIG. 3 is a system diagram of a cooling system of the
high-temperature part of a gas turbine in accordance with the
present invention.
[0017] FIG. 4 is a system diagram of a cooling system of the
high-temperature part of a gas turbine in accordance with the
present invention.
[0018] FIG. 5 is a system diagram of a cooling system of the
high-temperature part of a gas turbine in accordance with the
present invention.
[0019] FIG. 6 is a system diagram of a cooling system of the
high-temperature part of a gas turbine in accordance with the
present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
First Embodiment
[0020] With reference to FIG. 1, the first embodiment of the
present invention will now be described in detail. FIG. 1 shows a
cooling system of the high-temperature part of a gas turbine. The
gas turbine unit of FIG. 1 comprises mainly a compressor 1 to
compress and discharge gas, a combustor 2 which the gas compressed
by the compressor 1 is fed to, and a turbine 3 to be driven by the
combustion gas of the combustor 2.
[0021] Arranged from upstream to downstream in the cooling system
of this embodiment are a heat exchanger 4 for cooling the gas
compressed by the compressor 1, a means for separating liquid from
gas, a dust-collecting means for separating dust, etc. from gas, a
booster compressor 7, and, again, a dust-collecting means for
separating dust, etc. from gas.
[0022] Next, the cooling system of the high-temperature part of the
gas turbine will be described concretely along the flow of cooling
air.
[0023] The compressed air for cooling tapped from the compressor 1
through a branch line is fed to the heat exchanger 4. The
compressed air fed to the heat exchanger 4 is cooled down to about
130.degree. C. In this embodiment, the compressed air is indirectly
cooled by a refrigerant. The cooled compressed air is fed from the
heat exchanger 4 to a means for separating liquid from gas.
[0024] In this embodiment, a mist separator 5, which is a kind of
gas-liquid separator, is adopted as the means for separating liquid
from the gas fed from the heat exchanger 4. The mist separator 5
separates mist from the compressed air introduced in it. Namely,
the mist due to the cooling of compressed air by the heat exchanger
4 is separated from the compressed air by the mist separator 5. By
having compressed air pass through the mist separator 5, mist in
the compressed air can be removed. Accordingly, erosion and
dust-adhesion inside the booster compressor 7 and the cooling-air
ducts of the high-temperature part of the turbine 3 disposed
downstream can be prevented. Namely, because the gas-liquid
separator is disposed below the heat exchanger 4 in the cooling
system, mist generated in the cooling step of the heat exchanger 4
can be removed. Because the gas-liquid separator is disposed below
the heat exchanger 4 and above the booster compressor 7 in the
cooling system, mist generated in the cooling step of the heat
exchanger 4 can be removed and erosion and dust-adhesion inside the
booster compressor 7 and the cooling-air ducts of the
high-temperature part of the turbine 3 can be prevented.
[0025] Thereafter, the compressed air is fed from the mist
separator 5 to the dust-collecting means for separating dust, etc.
from gas. In this embodiment, a cyclone 6 is adopted as the
dust-collecting means for separating dust, etc. from gas. In the
cyclone 6, alien substances such as dust contained in the cooled
compressed air can be removed. By purifying the cooled compressed
air in the cyclone 6, the booster compressor 7 disposed below the
cyclone 6 can be prevented from being damaged by dust, etc.
Besides, unlike a filter with metal meshes, the cyclone 6, which is
a centrifugal dust-collecting means, has hardly increasing pressure
loss during its continuous operation and hence is capable of
operating continuously over a long period of time. Namely, it is
free from such clogging of meshes and increasing pressure loss as
occur in a filter with meshes.
[0026] Namely, because the dust-collecting means for separating
dust, etc. from gas is disposed below the heat exchanger 4 and the
mist separator 5, dust, etc. in the air fed through the heat
exchanger 4 and the mist separator 5 can be removed. In addition,
because the dust-collecting means for separating dust, etc. from
gas is disposed below the heat exchanger 4 and the mist separator 5
and above the booster compressor 7, dust, etc. in the air fed
through the heat exchanger 4 and the mist separator 5 can be
removed and hence the booster compressor 7 can be prevented from
being damaged by dust, etc. On the other hand, by adopting a
cyclone 6 as the dust-collecting means for separating dust, etc.
from gas at this place, (i) the pressure loss hardly increases
during the continuous operation, (ii) long-time continuous
operation becomes possible, and (iii) such increase in pressure
loss due to the clogging of meshes as occurs in a filter with
meshes is rendered irrelevant.
[0027] Then, the compressed air is fed from the cyclone 6 to the
booster compressor 7. The booster compressor 7 raises the pressure
of the compressed air to a desired level. At the time, the pressure
is raised to about 50 kg/cm.sup.2 optimal for cooling the turbine
3. In this way, the pressure of the compressed air can be raised by
the booster compressor 7 to the level appropriate for cooling the
turbine 3.
[0028] The booster compressor 7 is driven by the turbine shaft
because cooling air always has to be fed to the turbine 3 while it
is operating. However, the arrangement of equipment or limited
available space may not allow such driving system to be adopted. In
this case, the booster compressor 7 is driven by an electric motor.
However, if the electric motor gets out of order, the supply of
cooling air to the turbine 3 goes down. Therefore, it is desirable
to provide the gas turbine unit with a protection device which
stops the gas turbine immediately when the electric motor of the
booster compressor 7 gets out of order. By providing the gas
turbine unit with a protection device having a means for detecting
the trouble of the electric motor and a means for stopping the gas
turbine based on a signal from the trouble-detecting means, the gas
turbine can be stopped to prevent it from being damaged in the
event that cooling air is not sufficiently supplied to the
high-temperature part of the gas turbine.
[0029] A dust-collecting means for separating dust, etc. from gas
is disposed below the booster compressor 7. In this embodiment, a
filter 8 is adopted as the dust-collecting means. The compressed
air for cooling is fed from the booster compressor 7 to the filter
8.
[0030] While the gas turbine is starting or stopping, the flow rate
of the cooling air fed from the compressor 1 is low. Accordingly,
the flow velocity at the inlet of the cyclone 6 is low, and hence
the cyclone 6 may not be able to exert its dust-collecting
capability well due to its working principle, purifying the cooling
air insufficiently. On the other hand, the dust-collecting
capability of the filter 8 which uses metal meshes or the like is
not affected by the low flow velocity of the cooling air. Thus,
when the flow velocity of the cooling air is low while the gas
turbine is starting or stopping, the cooling air can be purified by
the filter 8. Namely, by disposing, below the booster compressor 7,
the filter 8 which is a means for separating dust, etc. from the
cooling air by receiving the air with fiber or the like, the
cooling air can be purified even while the gas turbine is starting
or stopping and hence the flow velocity of the cooling air is
low.
[0031] Besides, while the turbine 3 is operating at its rated
speed, the pressure-raised compressed air (cooling air) is finally
purified with excellent accuracy before the air is fed to the
turbine 3. By purifying the air again, alien substances such as
rust produced in the booster compressor 7 can be removed. Namely,
because the dust-collecting means for separating dust, etc. from
gas is disposed, in the cooling system, between the booster
compressor 7 and the turbine 3, alien substances such as rust
produced in the booster compressor 7 can be removed while the gas
turbine is operating at its rated speed.
[0032] Then, the cooling air is fed from the filter 8 to the
turbine 3. In the turbine 3, the cooling air cools such
high-temperature part of the turbine 3 as the gas-turbine blades
and the rotor. Thereafter, the cooling air is fed to the combustor
2, and the heat gained by cooling the turbine 3 is recovered from
the air. Thus, the cooling system is of a closed type.
[0033] With the above cooling system, the generation efficiency of
gas-turbine power-generating equipment can be raised.
[0034] As FIG. 1 shows, in this cooling system, a bypass line 11
with a bypass valve 10 is laid around the turbine 3 below the
filter 8 so that the cooling air can be collected to the combustor
2 not through the line 9 leading to the turbine 3, but through the
bypass line 11.
[0035] While the gas turbine is starting, stopping, or operating
under a partial load, transient surges occur in the booster
compressor 7. Before the turbine unit gets into such condition, the
bypass valve 10 is opened to let part of the cooling air through
the bypass line 11 and thereby to control the air flow through the
line 9 and avoid such surging. Namely, by laying the bypass line
11, transient surging in the booster compressor 7 can be
checked.
[0036] On the other hand, while the gas turbine is starting,
stopping, or operating under a partial load, the temperature of the
combustion gas driving the turbine 3 is lower than that of the
combustion gas during the operation at the rated speed. Therefore,
the high-temperature part of the turbine 3 may be overcooled if all
the cooling air is fed to the turbine 3. If the high-temperature
part of the turbine 3 is cooled beyond the necessary degree, the
temperature difference between the surfaces of the high-temperature
part and the cooling holes may give rise to thermal stress, which
may cause damage to the turbine 3. Therefore, excess cooling air is
collected to the combustor 2 through the bypass line 11. Thus,
excessive cooling air can be prevented from flowing into the
turbine 3 because the bypass line 11 and the bypass valve 10 are
provided. Namely, by controlling the bypass valve 10, the cooling
air can be fed to the turbine 3 at an appropriate flow rate.
[0037] As described above, disposed in the bypass line 11 is the
bypass valve 10 that is a flow-rate control valve to control the
flow rate of the cooling air going around the turbine 3. By
controlling the bypass valve 10, the necessary flow rate of cooling
air to the turbine 3 can be secured and excess cooling air can be
collected through the bypass line 11 to the combustor 2.
[0038] Besides, the bypass line 11 may be laid not to the combustor
2, but to an upstream point above the heat exchanger 4 to achieve
the same effect.
[0039] Moreover, a more efficient cooling system for the
high-temperature part of the turbine 3 can be constructed by
monitoring metal temperatures of the high-temperature part of the
turbine 3 or the temperature of the collected cooling air, and
thereby determining whether the high-temperature part of the
turbine 3 is properly cooled or not and controlling the bypass
valve 10 accordingly. Namely, the cooling condition of the
high-temperature part of the turbine 3 can be monitored by
providing a means for detecting metal temperatures of the
high-temperature part of the turbine 3 or the temperature of the
collected cooling air. Besides, more appropriate cooling can be
made and a more efficient cooling system for the high-temperature
part of the turbine 3 can be constructed by providing a means for
adjusting the bypass valve 10 based on metal temperatures of the
high-temperature part of the turbine 3 or the temperature of the
collected cooling air when the high-temperature part of the turbine
3 is not properly cooled.
[0040] It is preferable to close the bypass valve 10 completely
from the point of view of the operating efficiency of the plant.
However, the cooling condition of the high-temperature part of the
turbine 3 may vary depending on weather conditions such as
atmospheric temperature. Therefore, it is desirable to control the
bypass valve 10 according to circumstances so as to optimize the
cooling condition of the high-temperature part of the turbine
3.
[0041] Besides, in case of a gas turbine unit in which the cooling
air after cooling the high-temperature part of the gas turbine is
not collected into the combustor, but exhausted together with the
combustion gas after driving the gas turbine, this cooling system
can feed cooling air which flows smoothly through the
high-temperature part of the gas turbine without causing the
clogging of cooling holes with dust, etc. and thereby improves the
reliability of the whole plant.
[0042] Further, in case of a closed-type cooling system, salient
effect is achieved by purifying the cooling air.
Second Embodiment
[0043] With reference to FIG. 2, the second embodiment of the
present invention will now be described in detail. FIG. 2 shows a
cooling system of the high-temperature part of a gas turbine.
[0044] The gas turbine unit of FIG. 2 comprises mainly a compressor
1 to compress and discharge gas, a combustor 2 which the gas
compressed by the compressor 1 is fed to, and a turbine 3 to be
driven by the combustion gas of the combustor 2.
[0045] Arranged from upstream to downstream in the cooling system
of this embodiment are a heat exchanger 4 for cooling the gas
compressed by the compressor 1, a means for separating liquid from
gas, a dust-collecting means for separating dust, etc. from gas, a
booster compressor 7, and, again, a dust-collecting means for
separating dust, etc. from gas.
[0046] In this embodiment, in the cooling system, disposed in the
vicinity of the outlet of a heat exchanger 4 as shown in FIG. 2 is
a thermometer 12 which is a means for detecting the temperature of
the cooling air (compressed air) from the heat exchanger 4. Because
the means for detecting the temperature of the cooling air
(compressed air) is provided, it can be monitored whether the
cooling air is properly cooled or not.
[0047] Also provided in this embodiment is a flow control valve 13
which is a means for controlling the flow rate of refrigerant to
the heat exchanger 4 in accordance with the temperature measured by
the thermometer 12. With the flow control valve 13, the flow rate
of refrigerant to the heat exchanger 4 can be controlled in
accordance with the temperature measured by the thermometer 12.
This control of refrigerant enables the management and the control
of the temperature of cooling air.
[0048] Moreover, provided in this embodiment is a differential
pressure gauge 14 which is a means for measuring the difference
between the pressures before and after the filter 8. The
differential pressure gauge 14 enables to monitor the difference
between the pressures before and after the filter 8 and the
clogging of meshes of the filter 8. If the difference between the
pressures before and after the filter 8 becomes large, the cooling
air cannot be fed at a sufficient flow rate to the high-temperature
part of the turbine 3. Therefore, it is desirable to provide the
gas turbine unit with a protection device which stops the gas
turbine immediately after such an event occurs.
[0049] Namely, damage to the gas turbine can be prevented by
stopping the gas turbine on the basis of the measured value of the
differential pressure gauge 14.
[0050] Also preferable for higher reliability is the configuration
that at least two filters 8 are disposed in the cooling system in
parallel and a selector valve 15 is disposed before and after each
filter 8 so as to make switchover between the filters 8 and keep
the difference between the pressures before and after the filter 8
in service in a permissible range.
Third Embodiment
[0051] With reference to FIG. 3, the third embodiment of the
present invention will now be described in detail. FIG. 3 shows a
cooling system of the high-temperature part of a gas turbine.
[0052] The gas turbine unit of FIG. 3 comprises mainly a compressor
1 to compress and discharge gas, a combustor 2 which the gas
compressed by the compressor 1 is fed to, and a turbine 3 to be
driven by the combustion gas of the combustor 2.
[0053] Arranged from upstream to downstream in the cooling system
of this embodiment are a heat exchanger 4 for cooling the gas
compressed by the compressor 1, a means for separating liquid from
gas, a dust-collecting means for separating dust, etc. from gas, a
booster compressor 7, and, again, a dust-collecting means for
separating dust, etc. from gas.
[0054] Particularly, in this embodiment, a plurality (at least two)
of filters 16 is disposed in parallel below the mist separator 5 in
the cooling system and a differential pressure gauge 14 is provided
to measure the difference between the pressures before and after
the filter 16 in service, as shown in FIG. 3. This configuration
enables to monitor the pressure loss of the filter 16 in service,
make switchover among the filters 16, and change metal meshes of
the filters 16 out of service.
[0055] Thus, continuous dust-collecting effect can be achieved,
trouble due to the clogging of filter meshes can be prevented, the
maintenance of filter meshes can be carried out easily, and an
appropriate cooling system can be constructed.
[0056] Namely, the filters 16, as described in the present
embodiments, can remove alien substances such as dust contained in
the cooled compressed air. By purifying the cooled compressed air
in the filters 16, the booster compressor 7 disposed downstream can
be prevented from being damaged by such alien substances. Besides,
the plurality of filters 16 is disposed in parallel, and the means
for measuring the differential pressure of the filters 16 and the
means for making switchover among the filters 16 are provided.
Therefore, even if the filter 16 in service gets clogged with dust,
etc. after a long service time, switchover among the filters 16 can
be made and the pressure loss of the filter 16 in service can be
prevented from increasing excessively.
[0057] Namely, because the dust-collecting means for separating
dust, etc. from gas is disposed below the heat exchanger 4 and the
mist separator 5, dust, etc. can be removed from the air fed
through the heat exchanger 4 and the mist separator 5. Besides,
because the dust-collecting means for separating dust, etc. from
gas is disposed below the heat exchanger 4 and the mist separator 5
and above the booster compressor 7, dust, etc. in the air fed
through the heat exchanger 4 and the mist separator 5 can be
removed and hence the booster compressor 7 can be prevented from
being damaged by dust, etc. Moreover, the plurality of filters 16
is disposed, as the means for separating dust, etc. from gas, in
parallel between the mist separator 5 and the booster compressor 7,
and the means for measuring the differential pressure of the
filters 16 and the means for making switchover among the filters 16
are provided. Therefore, the decrease of flow rate of the cooling
air due to the increase of pressure loss in the filters 16 during
the continuous operation of the gas turbine unit can be prevented,
and the gas turbine unit can be operated continuously over a long
time period.
Fourth Embodiment
[0058] With reference to FIG. 4, the fourth embodiment of the
present invention will now be described in detail. FIG. 4 shows a
cooling system of the high-temperature part of a gas turbine.
[0059] The gas turbine unit of FIG. 4 comprises mainly a compressor
1 to compress and discharge gas, a combustor 2 which the gas
compressed by the compressor 1 is fed to, and a turbine 3 to be
driven by the combustion gas of the combustor 2.
[0060] Arranged from upstream to downstream in the cooling system
of this embodiment are a heat exchanger 4 for cooling the gas
compressed by the compressor 1, a means for separating liquid from
gas and also separating dust, etc. from the same, a booster
compressor 7, and a dust-collecting means for separating dust, etc.
from gas.
[0061] In this embodiment, a gas-liquid-separating/dust-collecting
device 18 is provided as the means for separating liquid and dust,
etc. from gas. A filter 8 is disposed, below the booster compressor
7, as the dust-collecting means for separating dust, etc. from gas.
The gas-liquid-separating/dust-collecting device 18 in the present
embodiment serves as the means for separating liquid from gas (for
example, a mist separator 5) of the first embodiment and, at the
same time, as the dust-collecting means for separating dust, etc.
from gas (for example, a cyclone 6) of the first embodiment. In
addition to the double functionality, it contributes to the
simplification of the gas turbine unit.
[0062] Moreover, the filter 8 may be omitted in this embodiment to
simplify the unit because the filtering accuracy is relatively
stable even while the gas turbine is starting or stopping.
Fifth Embodiment
[0063] With reference to FIGS. 5 and 6, the fifth embodiment of the
present invention will now be described in detail. FIGS. 5 and 6
show a cooling system of the high-temperature part of a gas
turbine.
[0064] The gas turbine unit of FIGS. 5 and 6 comprises mainly a
compressor 1 to compress and discharge gas, a combustor 2 which the
gas compressed by the compressor 1 is fed to, and a turbine 3 to be
driven by the combustion gas of the combustor 2.
[0065] Arranged from upstream to downstream in the cooling system
of this embodiment are a heat exchanger 4 for cooling the gas
compressed by the compressor 1, a dust-collecting means for
separating dust, etc. from gas (for example, a cyclone 6), and a
booster compressor 7.
[0066] In the example of FIG. 5, a
gas-liquid-separating/dust-collecting device 18, which is a means
for separating liquid and dust, etc. from gas, is disposed below
the booster compressor 7.
[0067] Because the gas-liquid-separating/dust-collecting device 18
is disposed below the heat exchanger 4, the cyclone 6, and the
booster compressor 7 and above the turbine 3, mist to be generated
in the compressed air due to the cooling by the heat exchanger 4
can be removed and erosion and dust-adhesion inside the cooling-air
ducts of the high-temperature part of the turbine 3 can be
prevented. In addition, by adopting the double-functional
gas-liquid-separating/dust-collecting device 18, the gas turbine
unit can be simplified.
[0068] Further, because the gas-liquid-separating/dust-collecting
device 18 is disposed immediately before the turbine 3 in this
embodiment, highly reliable and highly purified air can be fed to
the turbine 3.
[0069] In the example of FIG. 6, a
gas-liquid-separating/dust-collecting device 18, which is a means
for separating liquid and dust, etc. from gas, is disposed between
the cyclone 6 and the booster compressor 7.
[0070] Because the gas-liquid-separating/dust-collecting device 18
is disposed below the heat exchanger 4 and the cyclone 6 and above
the booster compressor 7, mist to be generated in the compressed
air due to the cooling by the heat exchanger 4 can be removed and
erosion and dust-adhesion inside the booster compressor 7 and the
cooling-air ducts of the high-temperature part of the turbine 3 can
be prevented. In addition, by adopting the double-functional
gas-liquid-separating/dust-collecting device 18, the gas turbine
unit can be simplified.
INDUSTRIAL APPLICABILITY
[0071] According to the present invention, there is provided a gas
turbine unit and a gas-turbine cooling method capable of feeding
cooling air suitable for cooling the high-temperature part of the
gas turbine.
* * * * *