Technical Field
[0001] The present invention relates to a steam turbine plant comprising a condenser which
condenses exhaust steam which is steam exhausted from a steam turbine and turns the
exhaust steam back into water. Priority is claimed on Japanese Patent Application
No.
2013-065403, filed on March 27, 2013.
Background Art
[0002] Some steam turbine plants include a bypass steam line which guides steam bypassing
a steam turbine to a condenser. Since the bypass steam which is the steam guided into
the condenser from the bypass steam line has not operated the steam turbine, the bypass
steam has a higher pressure and a higher temperature than exhaust steam which has
operated the steam turbine.
[0003] As the above-described steam turbine plant, for example, there is a steam turbine
plant disclosed in PTL 1 below. The steam turbine of this steam turbine plant is an
axial exhaust type steam turbine which exhausts the steam in an axial direction in
which a turbine rotor extends. A condenser is disposed in the position in the axial
direction with respect to the steam turbine, that is, in the exhaust direction of
the steam. A bypass steam line, through which bypass steam bypassing the steam turbine
passes, is connected to the condenser.
[0004] In addition, for example, as the condenser of the axial exhaust type steam turbine,
there is a condenser disclosed in PTL 2 below. The condenser includes a set of heat-transfer
tubes configured of a plurality of heat-transfer tubes through the inner portions
of which sea water or the like passes, a main body which covers the set of heat-transfer
tubes, and an intermediate body which connects the steam turbine and the main body
and guides the steam from the steam turbine to the set of heat-transfer tubes in the
main body. The main body is disposed at a position in the axial direction with respect
to the steam turbine, and the intermediate body is connected to the side portion of
the main body.
[0005] In addition, a steam turbine plant disclosed in PTL 3 includes two steam turbines.
The two steam turbines are both downward exhaust type steam turbines which exhaust
steam downward. A condenser is disposed at a position below each steam turbine. The
bodies of the two condensers are connected to each other by a communication body on
the upper portion. A steam receiving box is disposed below the communication body.
A bypass steam line through which steam bypassing the steam turbine passes is connected
to the steam receiving box. The steam flowing into the steam receiving box from the
bypass steam line flows into the bodies of the two condensers via the communication
body.
Another example can be seen in PTL 4.
Citation List
Patent Literature
[0006]
[PTL 1] Japanese Unexamined Patent Application Publication No. 2003-148111
[PTL 2] Japanese Unexamined Patent Application Publication No. 9-273875
[PTL 3] Japanese Unexamined Patent Application Publication No. 7-167571
[PTL 4] JP S 63 201491 A
Summary of Invention
Technical Problem
[0007] In the steam turbine plant disclosed in PTL 1, since it is necessary to diffuse energy
of the bypass steam having a higher temperature and a higher pressure than the exhaust
steam to some extent, an end portion of the bypass steam line is connected into the
intermediate body of the condenser. In this structure, to allow the bypass steam of
which the energy has been diffused to some extent to flow into the main body, the
length of the intermediate body is lengthened, so that it is not possible to effectively
use an installation space of the steam turbine plant. Moreover, in this structure,
there is a concern that the bypass steam which flows into the intermediate body and
has a high temperature and a high pressure may reversely flow toward the steam turbine
side and damage the turbine rotor, a bearing or a shaft seal thereof, or the like.
In addition, since not only the exhaust steam from the steam turbine but also the
bypass steam from the bypass steam line flows into the set of heat-transfer tubes
in the main body via the intermediate body, there is another concern that a region
opposing the intermediate body in the set of heat-transfer tubes may be significantly
damaged compared with other portions.
[0008] Moreover, in the steam turbine plant of PTL 3, as described above, the steam receiving
box is disposed below the communication body through which the upper portions of the
bodies of the two condensers are connected with each other, and the bypass steam flows
into the steam receiving box. Accordingly, in the steam turbine plant disclosed in
PTL 3, it is not necessary to lengthen the length of the intermediate body among the
bodies of the condenser which guides the exhaust steam from the steam turbine into
the main body covering the set of heat-transfer tubes, as well as the possibility
that the bypass steam having a high temperature and a high pressure reversely flows
toward the steam turbine side is small. Also in this steam turbine plant, it is considered
that the communication body is connected to the intermediate body of each condenser.
Accordingly, not only the exhaust steam from the steam turbine but also the bypass
steam from the bypass steam line flows into the set of heat-transfer tubes in the
main body via the intermediate body, and it is presumed that the region opposing the
intermediate body in the set of heat-transfer tubes is significantly damaged compared
with other portions.
[0009] That is, not only in the steam turbine plant disclosed in PTL 1 but also in the steam
turbine plant disclosed in PTL 3, there are problems in that the set of heat-transfer
tubes of the condenser are locally damaged.
[0010] Accordingly, an object of the present invention is to provide a steam turbine plant
comprising a condenser capable of preventing local damage of the set of heat-transfer
tubes.
Solution to Problem
[0011] In order to solve the above problem, according to an aspect of the present invention,
there is provided a steam turbine plant comprising a steam turbine and condenser,
the condenser including: a set of heat-transfer tubes which is configured of a plurality
of heat-transfer tubes through the inner portions of which a medium which performs
heat-exchange with exhaust steam exhausted from a steam turbine passes and which turns
the exhaust steam back into water; a main body which covers the set of heat-transfer
tubes; an intermediate body which is positioned between the steam turbine and the
main body and connects both, and forms a primary steam passage for guiding the exhaust
steam from the steam turbine to the set of heat-transfer tubes in the main body; and
a bypass steam receiving section which receives bypass steam which has bypassed the
steam turbine, and guides the bypass steam to the set of heat-transfer tubes in the
main body via an opening formed in the main body, wherein the bypass steam receiving
section is disposed outside the primary steam passage, and the opening of the main
body is formed at a position at which the bypass steam mainly flows into the set of
heat-transfer tubes from a region different from an inflow region through which the
exhaust steam mainly flows into the set of heat-transfer tubes via the primary steam
passage. The steam turbine is a horizontal exhaust type which exhausts steam in an
axial direction in which a rotor of the steam turbine extends, or to a side of the
steam turbine, wherein the intermediate body is connected to a side portion of the
main body, and the bypass steam receiving section is disposed outside the primary
steam passage, and is provided on an upper portion of the main body.
[0012] In the above, "mainly flows into" means that the most steam flows into the set of
heat-transfer tubes from the region in the set of heat-transfer tubes.
[0013] In the condenser, the bypass steam flows into the set of heat-transfer tubes mainly
from the region different from the inflow region through which the exhaust steam mainly
flows into the set of heat-transfer tubes. Accordingly, in the condenser, since the
region through which the steam flows into the set of heat-transfer tubes is distributed,
it is possible to prevent local damage of the set of heat-transfer tubes.
[0014] Moreover, in the condenser, since the bypass steam receiving section is provided
outside the primary steam passage, compared with a case where the bypass steam is
guided to the intermediate body of the condenser, it is possible to decrease the length
of the intermediate body, and to effectively use an installation space of the steam
turbine plant. In addition, in the condenser, since the bypass steam does not directly
flow into the primary steam passage, the possibility that the bypass steam reversely
flows toward the steam turbine side is extremely low, and it is possible to prevent
damage of a turbine rotor of the steam turbine, a bearing or a shaft seal thereof,
or the like. Moreover, in the condenser, since a steam injector or a water injector
for injecting the bypass steam is not disposed in the intermediate body, it is possible
to decrease resistance to the exhaust steam passing through the intermediate body.
[0015] The condenser may further include a flow suppression member which suppresses the
flow of the bypass steam received by the bypass steam receiving section toward the
set of heat-transfer tubes.
[0016] In the condenser, since it is possible to suppress the flow of the bypass steam toward
the set of heat-transfer tubes, it is possible to further prevent damage of the set
of heat-transfer tubes.
[0017] Any one of the above condensers may further include a water injection section which
injects water into the bypass steam receiving section.
[0018] In the condenser, since it is possible to cool the bypass steam in the bypass steam
receiving section, it is possible to prevent damage of the set of heat-transfer tubes.
[0019] In any one of the above condensers, the steam turbine may be a horizontal exhaust
type which exhausts steam in an axial direction in which a rotor of the steam turbine
extends, or to a side of the steam turbine; the intermediate body may be connected
to a side portion of the main body; and the bypass steam receiving section may be
provided on one of an upper portion of the main body, and a side portion of the main
body which is opposite to a portion to which the intermediate body is connected based
on the set of heat-transfer tubes.
[0020] In any one of the above condensers except for the condenser for the horizontal exhaust
type steam turbine, the steam turbine may be a downward exhaust type which exhausts
steam to a lower side of the steam turbine; the intermediate body may be connected
to an upper portion of the main body, and the bypass steam receiving section may be
provided at a position opposite to the set of heat-transfer tubes in a horizontal
direction in a side portion of the main body.
[0021] In order to solve the above problem, according to another aspect of the present invention,
the steam turbine plant further includes a steam supply device which supplies steam
to the steam turbine, and a bypass steam line which guides the steam from the steam
supply device, as the bypass steam, to the bypass steam receiving section so that
the steam bypasses the steam turbine.
[0022] In order to solve the above problem, according to still another aspect of the present
invention, the steam turbine plant further includes a steam supply device which supplies
steam to the steam turbine, a feed water pump which returns water obtained by condensation
of the exhaust steam in the condenser to the steam supply device, a bypass steam line
which guides the steam from the steam supply device, as the bypass steam, to the bypass
steam receiving section so that the steam bypasses the steam turbine, and a water
injection line which guides the water pressurized by the feed water pump to the water
injection section.
[0023] Since the steam turbine plant also includes any one of the above-described condensers,
it is possible to prevent local damage of the set of heat-transfer tubes. Advantageous
Effects of Invention
[0024] According to an aspect of the present invention, since a region through which steam
flows into a set of heat-transfer tubes is distributed, it is possible to prevent
local damage of the set of heat-transfer tubes.
Brief Description of Drawings
[0025]
Fig. 1 is a system diagram of a steam turbine plant in a first embodiment according
to the present invention.
Fig. 2 is a system diagram of a steam turbine plant in a second embodiment according
to the present invention.
Fig. 3 is a system diagram of a steam turbine plant in a third embodiment according
to the present invention.
Fig. 4 is a schematic sectional view of a condenser in a first modification example
of the steam turbine plant according to the present invention.
Fig. 5 is a schematic sectional view of a condenser in a second modification example
of the steam turbine plant according to the present invention.
Fig. 6 is a schematic sectional view of a condenser in a third modification example
of the steam turbine plant according to the present invention.
Description of Embodiments
[0026] Hereinafter, various embodiments and various modification examples of a steam turbine
plant according to the present invention will be described with reference to the drawings.
First Embodiment
[0027] With reference to Fig. 1, a first embodiment of a steam turbine plant according to
the present invention will be described.
[0028] The steam turbine plant of the present embodiment includes a steam generator (steam
supply device) 1 such as a boiler, a high-pressure steam turbine 2 and a low-pressure
steam turbine 3 which are driven through steam generated by the steam generator 1,
a generator 5 which generates electricity by driving of each of the steam turbines
2 and 3, a reheater (steam supply device) 6 which reheats the steam exhausted from
the high-pressure steam turbine 2, a condenser 30 which condenses exhaust steam ES
which is the steam exhausted from the low-pressure steam turbine 3 and turns the exhaust
steam ES back into water, and a feed water pump 7 which returns the water in the condenser
30 to the steam generator 1.
[0029] Moreover, the steam turbine plant includes a high-pressure steam line 11 which guides
high-pressure steam HS which is steam generated by the steam generator 1 to the high-pressure
steam turbine 2, an exhaust high-pressure steam line 15 which guides steam exhausted
from the high-pressure steam turbine 2 to the reheater 6, a reheat steam line 13 which
guides reheat steam RS which is steam heated by the reheater 6 to the low-pressure
steam turbine 3, a bypass high-pressure steam line 12 which is branched from the high-pressure
steam line 11 and guides the high-pressure steam HS to the condenser 30, a bypass
reheat steam line 14 which is branched from the reheat steam line 13 and guides the
reheat steam RS to the condenser 30, a condensate line 16 which guides the water in
the condenser 30 to the feed water pump 7, a feed water line 17 which guides the water
from the feed water pump 7 to the steam generator 1, and an injection water line 18
which is branched from the feed water line 17 and guides the water to the condenser
30.
[0030] A high-pressure steam control valve 21, which controls a flow rate of the high-pressure
steam HS flowing into the high-pressure steam turbine 2, is provided in the high-pressure
steam line 11. A reheat steam control valve 23, which controls a flow rate of the
reheat steam RS flowing into the low-pressure steam turbine 3, is provided in the
reheat steam line 13. An on-off valve 22 is provided in the bypass high-pressure steam
line 12. In addition, an on-off valve 24 is also provided in the bypass reheat steam
line 14. In the feed water line 17, a feed water control valve 27, which controls
a flow rate of the water flowing into the steam generator 1, is provided at a position
closer to the steam generator 1 side than the position at which the injection water
line 18 is branched. An injection water control valve 28 which controls a flow rate
of the water injected into the condenser 30 is provided in the injection water line
18.
[0031] Each of the high-pressure steam turbine 2 and the low-pressure steam turbine 3 includes
a turbine rotor which rotates about an axis line, and a casing which rotatably covers
the turbine rotor. The turbine rotor of the high-pressure steam turbine 2 and the
turbine rotor of the low-pressure steam turbine 3 rotate about the same axis line,
and the turbine rotors are connected to each other. In addition, a generator rotor
of the generator 5 is connected to the turbine rotor of the high-pressure steam turbine
2.
[0032] The low-pressure steam turbine 3 is an axial exhaust type steam turbine which exhausts
steam in the axial direction in which the turbine rotor extends. Accordingly, in the
casing of the low-pressure steam turbine 3, the rear side opposite to the high-pressure
steam turbine 2 in the axial direction is open as an exhaust port 4.
[0033] The condenser 30 is of a type corresponding to the axial exhaust type steam turbine,
and is disposed on the rear side of the low-pressure steam turbine 3. The condenser
30 includes a set of heat-transfer tubes 32 which is configured of a plurality of
heat-transfer tubes 31, a main body 35 which covers the set of heat-transfer tubes
32, an intermediate body 41 which is positioned between the low-pressure steam turbine
3 and the main body 35 and connects both, a bypass steam receiving section 51 which
receives bypass high-pressure steam BHS which is the steam from the bypass high-pressure
steam line 12 and bypass reheat steam BRS which is the steam from the bypass reheat
steam line 14, and a water injector (water injection section) 56 which injects the
water from the injection water line 18 into the condenser 30. In addition, hereinafter,
one or both of the bypass high-pressure steam BHS and the bypass reheat steam BRS
may be simply referred to as bypass steam BS.
[0034] The main body 35 is disposed at an interval on the rear side of the low-pressure
steam turbine 3. The intermediate body 41 extends rearward from the exhaust port 4
of the low-pressure steam turbine 3 and connects the exhaust port 4 of the low-pressure
steam turbine 3 and the main body 35. The portion of the main body 35 to which the
intermediate body 41 is connected is a side portion of the main body 35 and is on
a low-pressure steam turbine 3 side. A portion of the main body 35 which is connected
to the intermediate body 41 is open. The exhaust steam ES, which is the steam exhausted
from the low-pressure steam turbine 3, flows into the main body 35 from the opening
(hereinafter, referred to as an exhaust steam inlet 36) via the intermediate body
41. Accordingly, the intermediate body 41 forms a portion of a primary steam passage
42 which guides the exhaust steam ES from the low-pressure steam turbine 3 to the
set of heat-transfer tubes 32 in the main body 35. In addition, the primary steam
passage 42 is configured of the internal space of the intermediate body 41, and a
space between the exhaust steam inlet 36 of the main body 35 and the set of heat-transfer
tubes 32 in the main body 35. For example, a cooling medium such as sea water flows
to the plurality of heat-transfer tubes 31 configuring the set of heat-transfer tubes
32. In each heat-transfer tube 31, heat exchange is performed between the cooling
medium flowing through the inner portion of the tube and the exhaust steam ES of the
outer portion of the tube, and the exhaust steam ES is condensed and turned back into
water. A hot well 38 in which the water obtained by the condensation of the exhaust
steam ES is accumulated is formed at the lower portion of the inner portion of the
main body 35. The condensate line 16 is connected to the lower portion of the main
body 35.
[0035] The bypass steam receiving section 51 includes a bypass steam receiving box 52 in
which a space for receiving the bypass steam BS is formed in the inner portion, a
high-pressure steam injector 53 which is connected to the bypass high-pressure steam
line 12 and injects the bypass high-pressure steam BHS inside the bypass steam receiving
box 52, and a reheat steam injector 54 which is connected to the bypass reheat steam
line 14 and injects the bypass reheat steam BRS inside the bypass steam receiving
box 52.
[0036] The bypass steam receiving box 52 is connected and fixed to the upper portion of
the main body 35. A connection portion between the bypass steam receiving box 52 and
the main body 35 is open, and from this opening (hereinafter, referred to as a bypass
steam inlet 37) the bypass steam BS, which is injected into the bypass steam receiving
box 52, flows into the main body 35. The high-pressure steam injector 53 and the reheat
steam injector 54 are both porous tubes in which a large number of through-holes are
formed in the tube. In addition, in the bypass steam receiving box 52, a water injector
56 is disposed at a position below the high-pressure steam injector 53 and the reheat
steam injector 54, that is, a position on the set of heat-transfer tubes 32 side.
The water injector 56 is a tube provided with a plurality of nozzles injecting water.
The plurality of nozzles are provided in an upper part of the tube, and inject the
water upward, that is, toward the side of the high-pressure steam injector 53 and
the reheat steam injector 54.
[0037] Next, an operation of the above-described steam turbine plant will be described.
[0038] The steam generated by the steam generator 1 flows into the casing of the high-pressure
steam turbine 2 via the high-pressure steam line 11 as the high-pressure steam HS,
and drives the high-pressure steam turbine 2. Meanwhile, the high-pressure steam control
valve 21 controls the flow rate of the high-pressure steam HS flowing into the casing
of the high-pressure steam turbine 2. The on-off valve 22 provided in the bypass high-pressure
steam line 12 is fully closed. The high-pressure steam HS exhausted from the high-pressure
steam turbine 2 flows into the reheater 6 via the exhaust high-pressure steam line
15, and is reheated. The steam heated by the reheater 6 flows into the casing of the
low-pressure steam turbine 3 via the reheat steam line 13 as the reheat steam RS,
and drives the low-pressure steam turbine 3. Meanwhile, the reheat steam control valve
23 controls the flow rate of the reheat steam RS which flows into the casing of the
low-pressure steam turbine 3. In addition, the on-off valve 24 provided in the bypass
reheat steam line 14 is fully closed.
[0039] When the high-pressure steam turbine 2 and the low-pressure steam turbine 3 are driven,
the generator 5 generates electricity.
[0040] The reheat steam RS which has driven the low-pressure steam turbine 3 is exhausted
from the exhaust port 4 of the low-pressure steam turbine 3 as the exhaust steam ES,
and flows into the set of heat-transfer tubes 32 in the main body 35 through the intermediate
body 41 of the condenser 30. That is, the exhaust steam ES flows into the set of heat-transfer
tubes 32 through the primary steam passage 42 in the condenser 30 from the exhaust
port 4 of the low-pressure steam turbine 3. In this case, the exhaust steam ES flows
mainly from a region 33 of a side portion opposing the exhaust steam inlet 36 of the
main body 35 in the set of heat-transfer tubes 32 into the set of heat-transfer tubes
32. In addition, here, "flows mainly" means that the most exhaust steam ES flows from
the region 33 of the side portion opposing the exhaust steam inlet 36 of the main
body 35 in the set of heat-transfer tubes 32 into the set of heat-transfer tubes 32.
[0041] The exhaust steam ES flowing into the set of heat-transfer tubes 32 or reaching the
vicinity of the set of heat-transfer tubes 32 exchanges heat with the cooling medium
flowing through the heat-transfer tubes 31 configuring the set of heat-transfer tubes
32, is condensed, and thus, becomes water. This water is accumulated in the hot well
38 positioned at the lower portion of the main body 35. The water accumulated in the
hot well 38 returns to the steam generator 1 via the condensate line 16, the feed
water pump 7, and the feed water line 17. Meanwhile, the feed water control valve
27 controls the flow rate of the water flowing into the steam generator 1. In addition,
the injection water control valve 28 is fully closed.
[0042] During the above-described steady operation, for example, when the high-pressure
steam turbine 2 and the low-pressure steam turbine 3 are stopped by an instruction
of stop of a power supply from a power system connected to the generator 5, or the
like, the high-pressure steam control valve 21 and the reheat steam control valve
23 are switched from an open state to a fully closed state. In addition, the on-off
valves 22 and 24 provided in the bypass high-pressure steam line 12 and the bypass
reheat steam line 14 are switched from a fully closed state to a fully open state.
As a result, the high-pressure steam HS from the steam generator 1 is injected into
the bypass steam receiving box 52 via the high-pressure steam line 11, the bypass
high-pressure steam line 12, and the high-pressure steam injector 53 as the bypass
high-pressure steam BHS. In addition, the reheat steam RS from the reheater 6 is injected
into the bypass steam receiving box 52 via the reheat steam line 13, the bypass reheat
steam line 14, and the reheat steam injector 54 as the bypass reheat steam BRS. Since
the bypass high-pressure steam BHS injected into the bypass steam receiving box 52
has not operated the high-pressure steam turbine 2, the bypass high-pressure steam
BHS has a higher temperature and a higher pressure than the high-pressure steam HS
which has operated the high-pressure steam turbine 2. In addition, since the bypass
reheat steam BRS injected into the bypass steam receiving box 52 has not operated
the low-pressure steam turbine 3, the bypass reheat steam BRS has a higher temperature
and a higher pressure than the reheat steam RS (exhaust steam ES) which has operated
the low-pressure steam turbine 3. Accordingly, the bypass steam BS having a higher
temperature and a higher pressure than the exhaust steam ES flowing into the main
body 35 via the intermediate body 41 flows into the bypass steam receiving box 52.
[0043] In this case, the injection water control valve 28 is opened, and a portion of the
water from the feed water pump 7 is injected into the bypass steam receiving box 52
via the injection water line 18 and the water injector 56. The water injected into
the bypass steam receiving box 52 exchanges heat with the bypass steam BS having a
high temperature and a high pressure, and thus, the temperature of the bypass steam
BS decreases. Moreover, the water injected into the bypass steam receiving box 52
functions as a curtain with respect to the bypass steam BS, and suppresses the flow
of the bypass steam BS into the main body 35. Moreover, in this process, most water
becomes steam.
[0044] The bypass steam BS and the water which becomes steam through the heat exchange with
the bypass steam BS flow into the set of heat-transfer tubes 32. In this case, the
bypass steam BS or the like flows into the set of heat-transfer tubes 32 mainly from
a region 34 of the upper portion opposing the bypass steam inlet 37 of the main body
35 in the set of heat-transfer tubes 32. The bypass steam BS or the like flowing into
the set of heat-transfer tubes 32 or reaching the vicinity of the set of heat-transfer
tubes 32 exchanges heat with the cooling medium flowing through the heat-transfer
tubes 31 configuring the set of heat-transfer tubes 32, is condensed, and becomes
water. This water is accumulated in the hot well 38 positioned at the lower portion
of the main body 35. A portion of the water accumulated in the hot well 38 returns
to the steam generator 1 via the condensate line 16, the feed water pump 7, and the
feed water line 17. In addition, the remaining water is injected into the bypass steam
receiving box 52 via the injection water line 18 and the water injector 56.
[0045] Thus, in the present embodiment, the bypass steam BS flows into the set of heat-transfer
tubes 32 mainly from the region 34 of the upper portion of the set of heat-transfer
tubes 32 while the exhaust steam ES flows into the set of heat-transfer tubes 32 mainly
from the region 33 opposing the exhaust steam inlet 36 of the main body 35 in the
side portion of the set of heat-transfer tubes 32 via the primary steam passage 42.
That is, in the present embodiment, the region 33 in the set of heat-transfer tubes
32 through which the exhaust steam ES flows into the set of heat-transfer tubes 32
is different from the region 34 in the set of heat-transfer tubes 32 through which
the bypass steam BS flows into the set of heat-transfer tubes 32. Accordingly, in
the present embodiment, it is possible to prevent local damage of the set of heat-transfer
tubes 32.
[0046] When the bypass steam BS is guided to the intermediate body 41 of the condenser 30,
since it is necessary to allow the bypass steam BS to flow into the main body 35 after
energy of the bypass steam BS having a high temperature and a high pressure is diffused
to some extent, the length of the intermediate body 41 is lengthened. Moreover, in
this case, there is a concern that the bypass steam BS, which flows into the intermediate
body 41 and has a high temperature and a high pressure, may reversely flow toward
the steam turbine side and damage the turbine rotor of the steam turbine, a bearing
or a shaft seal thereof, or the like. In addition, in this case, since the steam injector
for injecting the bypass steam BS or the water injector is disposed in the intermediate
body 41, resistance to the exhaust steam ES passing through the intermediate body
41 increases.
[0047] However, in the present embodiment, since the bypass steam receiving section 51 is
provided outside the primary steam passage 42, compared with the case where the bypass
steam BS is guided to the intermediate body 41 of the condenser 30, it is possible
to shorten the length of the intermediate body 41, and to effectively use an installation
space of the steam turbine plant. In addition, in the present embodiment, since the
bypass steam BS does not directly flow into the primary steam passage 42 in the intermediate
body 41, the possibility that the bypass steam BS reversely flows toward the steam
turbine side is extremely low, and it is possible to prevent damage of the turbine
rotor of the steam turbine, the bearing or the shaft seal thereof, or the like. Moreover,
in the present embodiment, since the steam injector which injects the bypass steam
BS or the water injector is not disposed in the intermediate body 41, it is possible
to decrease the resistance to the exhaust steam ES passing through the intermediate
body 41.
Second Embodiment
[0048] With reference to Fig. 2, a second embodiment of the steam turbine plant according
to the present invention will be described.
[0049] The steam turbine plant of the present embodiment is substantially the same as the
steam turbine plant of the first embodiment. However, the present embodiment is different
from the first embodiment in that a bypass steam receiving section 51a of a condenser
30a is provided on a side portion of a main body 35a in the present embodiment.
[0050] Similarly to the bypass steam receiving section 51 of the first embodiment, the bypass
steam receiving section 51a of the present embodiment also includes the bypass steam
receiving box 52, the high-pressure steam injector 53, and the reheat steam injector
54. The bypass steam receiving box 52 is connected and fixed to a side opposite to
the portion to which the intermediate body 41 is connected based on the set of heat-transfer
tubes 32 in the side portion of the main body 35a. The connection portion between
the bypass steam receiving box 52 and the main body 35a is open, and this opening
forms a bypass steam inlet 37a through which the bypass steam BS from the bypass steam
receiving box 52 flows into the main body 35a.
[0051] As described above, in the present embodiment, the bypass steam BS flows into the
set of heat-transfer tubes 32 mainly from a region 34a opposing the bypass steam inlet
37a opposite to the exhaust steam inlet 36 based on the set of heat-transfer tubes
32 while the exhaust steam ES flows into the set of heat-transfer tubes 32 mainly
from the region 33 opposing the exhaust steam inlet 36 of the main body 35a in the
side portion of the set of heat-transfer tubes 32 via the inner portion of the intermediate
body 41. That is, similarly to the first embodiment, also in the present embodiment,
the region 33 in the set of heat-transfer tubes 32 through which the exhaust steam
ES flows into the set of heat-transfer tubes 32 is different from the region 34a in
the set of heat-transfer tubes 32 through which the bypass steam BS flows into the
set of heat-transfer tubes 32. In addition, similarly to the first embodiment, also
in the present embodiment, the bypass steam receiving section 51a is provided outside
the primary steam passage 42. Accordingly, also in the present embodiment, it is possible
to obtain substantially the same effects as the first embodiment.
[0052] However, since the bypass steam receiving section 51a is provided on the side portion
of the main body 35a in the present embodiment, compared to the first embodiment,
the use efficiency of a planar installation space of the steam turbine plant is low
in the present embodiment. On the other hand, in the present embodiment, since the
bypass steam receiving section 51a is provided on the side opposite to the side to
which the intermediate body 41 is connected based on the set of heat-transfer tubes
32, it is possible to further decrease the possibility of the bypass steam BS reversely
flowing toward the steam turbine side than in the first embodiment.
[0053] In addition, in both the first embodiment and the second embodiment, the low-pressure
steam turbine 3 is an axial exhaust type and the condensers 30 and 30a are types corresponding
to the axial exhaust type. However, even when the low-pressure steam turbine is a
side exhaust type and the condensers are types corresponding to the side exhaust type,
similarly to the above-described embodiments, the present invention can be applied.
In addition, when the steam turbine is the side exhaust type, the condenser is disposed
on the side of the steam turbine.
Third Embodiment
[0054] With reference to Fig. 3, a third embodiment of the steam turbine plant according
to the present invention will be described.
[0055] Components of the steam turbine plant of the present embodiment are the same as the
components of the steam turbine plants of the first and second embodiments. However,
a low-pressure steam turbine 3b and a condenser 30b which are the components of the
steam turbine plant of the present embodiment are different from the low-pressure
steam turbines 3 and the condensers 30 and 30a of the steam turbine plants of the
first and second embodiments.
[0056] The low-pressure steam turbine 3b of the present embodiment is a downward exhaust
type which exhausts steam downward. Accordingly, the lower side of the casing of the
low-pressure steam turbine 3b of the present embodiment is open as an exhaust port
4b.
[0057] The condenser 30b is of a type corresponding to the downward exhaust type steam turbine,
and is disposed below the low-pressure steam turbine 3b. Similarly to the condensers
30 and 30a of the first and second embodiments, the condenser 30b also includes the
set of heat-transfer tubes 32, a main body 35b which covers the set of heat-transfer
tubes 32, an intermediate body 41b which is disposed between the low-pressure steam
turbine 3b and the main body 35b and connects both, a bypass steam receiving section
51b, and the water injector 56 (water injection section).
[0058] The main body 35b is disposed at an interval below the low-pressure steam turbine
3b. The intermediate body 41b extends downward from the exhaust port 4b of the low-pressure
steam turbine 3b, and connects the exhaust port 4b of the low-pressure steam turbine
3b and the main body 35b. The portion of the main body 35 which is connected to the
intermediate body 41b is the upper portion of the main body 35b. A portion of the
main body 35b which is connected to the intermediate body 41b is open, and this opening
forms an exhaust steam inlet 36b through which the exhaust steam ES flows into the
main body 35b. Accordingly, also in the present embodiment, the intermediate body
41b forms a portion of a primary steam passage 42b which guides the exhaust steam
ES from the low-pressure steam turbine 3b to the set of heat-transfer tubes 32 in
the main body 35b. Moreover, also in the present embodiment, the hot well 38, in which
the water obtained by the condensation of the exhaust steam ES is accumulated, is
formed at the lower portion of the inner portion of the main body 35b.
[0059] Similarly to the above-described embodiments, the bypass steam receiving section
51b includes the bypass steam receiving box 52, the high-pressure steam injector 53
which injects the bypass high-pressure steam BHS, and the reheat steam injector 54
which injects the bypass reheat steam BRS.
[0060] The bypass steam receiving box 52 is connected and fixed to the side portion of the
main body 35b. A connection portion between the bypass steam receiving box 52 and
the main body 35b is open, and this opening forms a bypass steam inlet 37b through
which the bypass steam BS flows into the main body 35b. Similarly to the first and
second embodiments, both the high-pressure steam injector 53 and the reheat steam
injector 54 are disposed inside the bypass steam receiving box 52. In addition, similarly
to the first and second embodiments, the water injector 56 is also disposed at the
position closer to the set of heat-transfer tubes 32 side than the high-pressure steam
injector 53 and the reheat steam injector 54 in the bypass steam receiving box 52.
The plurality of nozzles of the water injector 56 inject water to the side of the
high-pressure steam injector 53 and the reheat steam injector 54.
[0061] Thus, in the present embodiment, the bypass steam BS flows into the set of heat-transfer
tubes 32 mainly from a region 34b of the side portion of the set of heat-transfer
tubes 32 while the exhaust steam ES flows into the set of heat-transfer tubes 32 mainly
from a region 33b of the upper portion in the set of heat-transfer tubes 32 via the
intermediate body 41b. That is, similarly to the first and second embodiments, also
in the present embodiment, the region 33b in the set of heat-transfer tubes 32 through
which the exhaust steam ES flows into the set of heat-transfer tubes 32 is different
from the region 34b in the set of heat-transfer tubes 32 through which the bypass
steam BS flows into the set of heat-transfer tubes 32. Moreover, similarly to the
first and second embodiments, also in the present embodiment, the bypass steam receiving
section 51b is provided outside the primary steam passage 42b. Accordingly, also in
the present embodiment, it is possible to obtain substantially the same effects as
the first and second embodiments. That is, also in the present embodiment, it is possible
to prevent local damage of the set of heat-transfer tubes 32. In addition, also in
the present embodiment, compared with the case where the bypass steam BS is guided
to the intermediate body 41b of the condenser 30b, it is possible to shorten the length
of the intermediate body 41b. In addition, also in the present embodiment, it is possible
to extremely decrease the possibility of the bypass steam BS reversely flowing toward
the low-pressure steam turbine 3b side, and it is possible to decrease resistance
to the exhaust steam ES passing through the intermediate body 41b.
[0062] Thus, as in the present embodiment, even when the low-pressure steam turbine 3b is
the downward exhaust type and the condenser 30b is the type corresponding to the downward
exhaust type, the present invention can be applied. That is, as described above, regardless
of whether the steam turbine is the horizontal exhaust type, which is the axial exhaust
type or the side exhaust type, or the steam turbine is the downward exhaust type,
the present invention can be applied according to the exhaust type of the steam turbine.
First Modification Example of Condenser
[0063] With reference to Fig. 4, a first modification example of the condenser 30 in the
first embodiment will be described.
[0064] In the condenser 30 in the first embodiment, the water injector 56 is disposed at
the position closer to the set of heat-transfer tubes 32 side than the high-pressure
steam injector 53 and the reheat steam injector 54 in the bypass steam receiving box
52. In a condenser 30c of the present modification example, the water injector 56
is disposed farther away from the set of heat-transfer tubes 32 side than the high-pressure
steam injector 53 and the reheat steam injector 54 in the bypass steam receiving box
52 of a bypass steam receiving section 51c. In other words, in the present modification
example, the high-pressure steam injector 53 and the reheat steam injector 54 are
disposed at positions on the set of heat-transfer tubes 32 side from the water injector
56. Similarly to the above-described embodiments, the nozzles of the water injector
56 inject water to the side of the high-pressure steam injector 53 and the reheat
steam injector 54. Accordingly, also in the present modification example, the bypass
steam BS, which is injected from the high-pressure steam injector 53 and the reheat
steam injector 54 into the bypass steam receiving box 52, can be cooled by the water
injected from the water injector 56.
[0065] In addition, the present modification example is the modification example of the
condenser 30 in the first embodiment. However, the condensers 30a and 30b of the second
and third embodiments can be similarly modified.
Second Modification Example of Condenser
[0066] With reference to Fig. 5, a second modification example which is a further modification
example of the condenser 30c in the first modification example will be described.
[0067] In a condenser 30d of the present modification example, a flow suppression member,
which suppresses the flow of the bypass steam BS received by the bypass steam receiving
section 51c of the condenser 30c toward the set of heat-transfer tubes 32, is added
to the condenser 30c of the first modification example. The flow suppression member
is an impingement plate 58 which is disposed between a set of injectors 55, which
is a collection of the high-pressure steam injector 53, the reheat steam injector
54, and the water injector 56 inside the bypass steam receiving box 52, and the set
of heat-transfer tubes 32 in the main body 35. The impingement plate 58 spreads in
a direction perpendicular to a receiving portion-tube set direction which is from
the set of injectors 55 or the bypass steam receiving section 51c toward the set of
heat-transfer tubes 32.
[0068] As in the present modification example, when the impingement plate 58 is disposed
between the set of injectors 55 and the set of heat-transfer tubes 32, flow velocity
of the steam flowing from the set of injectors 55 side into the set of heat-transfer
tubes 32 decreases, and it is possible to further prevent the damage of the set of
heat-transfer tubes 32.
Third Modification Example of Condenser
[0069] With reference to Fig. 6, a third modification example which is a further modification
example of the condenser 30c in the first modification example will be described.
[0070] Similarly to the second modification example, also in a condenser 30e of the present
modification example, a flow suppression member, which suppresses the flow of the
bypass steam BS received by the bypass steam receiving section 51c of the condenser
30c toward the set of heat-transfer tubes 32, is added to the condenser 30c of the
first modification example. The flow suppression member of the present modification
example is a plurality of impingement rods 59 which are disposed between the set of
injectors 55 and the set of heat-transfer tubes 32 in the main body 35. The plurality
of impingement rods 59 all extend in the direction perpendicular to the receiving
portion-tube set direction which is from the set of injectors 55 or the bypass steam
receiving section 51c toward the set of heat-transfer tubes 32, and are disposed at
intervals in the direction perpendicular to the receiving portion-tube set direction
and to the direction in which each impingement rod 59 extends.
[0071] Also in the present modification example, since the plurality of impingement rods
59 are disposed between the set of injectors 55 and the set of heat-transfer tubes
32, flow velocity of the steam flowing from the set of injectors 55 into the set of
heat-transfer tubes 32 decreases, and it is possible to further prevent the damage
of the set of heat-transfer tubes 32.
[0072] Moreover, in the second and third modification examples, each of the flow suppression
members is disposed inside the main body 35. However, the flow suppression member
may be disposed inside the bypass steam receiving box 52 as long as the flow suppression
member is disposed between the set of injectors 55 and the set of heat-transfer tubes
32.
[0073] In addition, both the second and third modification examples are the modification
examples of the condenser 30 in the first modification example. However, the condensers
of the first to third embodiments can be similarly modified.
[0074] In the condenser 30c of the first modification example, the high-pressure steam injector
53 and the reheat steam injector 54 are disposed on the set of heat-transfer tubes
32 side from the water injector 56, and thus, it is not possible to expect the curtain
effects of the flow of the bypass steam BS toward the set of heat-transfer tubes 32
being suppressed by the water injected from the water injector 56. Accordingly, it
is more effective if the flow suppression member is provided in the condenser of the
first modification example with respect to the first to third embodiments rather than
the condensers of the first to third embodiments.
Other Modification Examples
[0075] In the above embodiments and modification examples, the present invention is applied
to the steam turbine plant which includes the high-pressure steam turbine, the low-pressure
steam turbine, and the condenser through which the exhaust steam from the low-pressure
steam turbine is turned back into water. However, the present invention may also be
applied to a steam turbine plant which includes a high-pressure steam turbine, an
intermediate-pressure steam turbine, a low-pressure turbine, and a condenser through
which the exhaust steam ES from any one of these steam turbines is turned back into
water. In addition, the present invention may also be applied to a steam turbine plant
which includes one kind of steam turbine and a condenser through which the exhaust
steam from the steam turbine is turned back into water. That is, as long as the steam
turbine plant includes a steam turbine and a condenser for the steam turbine, the
present invention may be applied to any steam turbine plant.
Industrial Applicability
[0076] According to an aspect of the present invention, it is possible to prevent local
damage of the set of heat-transfer tubes.
Reference Signs List
[0077] 1: STEAM GENERATOR (STEAM SUPPLY DEVICE), 2: HIGH-PRESSURE STEAM TURBINE, 3, 3b:
LOW-PRESSURE STEAM TURBINE (OR SIMPLY STEAM TURBINE), 5: GENERATOR, 6: REHEATER (STEAM
SUPPLY DEVICE), 7: FEED WATER PUMP, 11: HIGH-PRESSURE STEAM LINE, 12: BYPASS HIGH-PRESSURE
STEAM LINE, 13: REHEAT STEAM LINE, 14: BYPASS REHEAT STEAM LINE, 15: EXHAUST HIGH-PRESSURE
STEAM LINE, 16: CONDENSATE LINE, 17: FEED WATER LINE, 18: INJECTION WATER LINE, 30,
30a, 30b, 30c, 30d, 30e: CONDENSER, 31: HEAT-TRANSFER TUBE, 32: SET OF HEAT-TRANSFER
TUBES, 33, 33b, 34, 34a, 34b: REGION, 35, 35a, 35b: MAIN BODY, 36 36b: EXHAUST STEAM
INLET (OPENING), 37, 37a, 37b: BYPASS STEAM INLET (OPENING), 41: INTERMEDIATE BODY,
42: PRIMARY STEAM PASSAGE, 51, 51a, 51b, 51c: BYPASS STEAM RECEIVING SECTION, 52:
BYPASS STEAM RECEIVING BOX, 53: HIGH-PRESSURE STEAM INJECTOR, 54: REHEAT STEAM INJECTOR,
55: SET OF INJECTORS, 56: WATER INJECTOR (WATER INJECTION SECTION), 58: IMPINGEMENT
PLATE, 59: IMPINGEMENT ROD