U.S. patent application number 12/192966 was filed with the patent office on 2010-02-18 for steam turbine clutch and method for disengagement of steam turbine from generator.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Gregory L. DiAntonio, William Thomas Parry.
Application Number | 20100038917 12/192966 |
Document ID | / |
Family ID | 41528293 |
Filed Date | 2010-02-18 |
United States Patent
Application |
20100038917 |
Kind Code |
A1 |
DiAntonio; Gregory L. ; et
al. |
February 18, 2010 |
STEAM TURBINE CLUTCH AND METHOD FOR DISENGAGEMENT OF STEAM TURBINE
FROM GENERATOR
Abstract
A power generation system including: at least one elevated steam
turbine receiving input steam at an elevated pressure and
exhausting steam as low pressure steam; a low pressure steam
turbine receiving low pressure steam exhausted from the elevated
steam turbine, and a drive shaft for the low pressure steam turbine
connected to a clutch which is reasonably coupled to a power
generator, wherein the clutch has a first position in which power
from the low pressure steam turbine is applied to the power
generator and a second position in which power from the low
pressure steam turbine is not applied to the generator.
Inventors: |
DiAntonio; Gregory L.;
(Marietta, GA) ; Parry; William Thomas; (Rexford,
NY) |
Correspondence
Address: |
NIXON & VANDERHYE P.C.
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
41528293 |
Appl. No.: |
12/192966 |
Filed: |
August 15, 2008 |
Current U.S.
Class: |
290/4C ; 60/645;
60/670 |
Current CPC
Class: |
F01K 7/22 20130101 |
Class at
Publication: |
290/4.C ; 60/645;
60/670 |
International
Class: |
F01D 15/10 20060101
F01D015/10; F01K 13/00 20060101 F01K013/00; F01K 23/16 20060101
F01K023/16 |
Claims
1. A power generation system comprising: at least one elevated
steam turbine receiving input steam at an elevated pressure and
exhausting steam as low pressure steam; a low pressure steam
turbine receiving low pressure steam exhausted from the elevated
steam turbine, and a drive shaft for the low pressure steam turbine
connected to a clutch which is reasonably coupled to a power
generator, wherein the clutch has a first position in which power
from the low pressure steam turbine is applied to the power
generator and a second position in which power from the low
pressure steam turbine is not applied to the generator.
2. The power generation system in claim 1 further comprising a
first low pressure steam valve in a conduit for low pressure steam
flowing to the low pressure steam turbine and a second low pressure
steam valve in a conduit for low pressure steam flowing to a steam
process extraction device, wherein the first low pressure steam
valve is open while the second low pressure steam valve is closed,
and the first low pressure steam valve is closed while the second
low pressure steam valve is open.
3. The power generation system in claim 1 wherein the low pressure
steam turbine includes a first low pressure steam turbine, and a
second low pressure steam turbine and the clutch engages and
disengages the second low pressure steam turbine from the first low
pressure steam turbine, and the first low pressure steam turbine is
coupled to the generator.
4. The power generation system in claim 3 further comprising a
first low pressure steam valve in a conduit for the low pressure
steam flowing to the second low pressure steam turbine, wherein the
first low pressure steam valve is open while the clutch engages the
second low pressure steam turbine to the first low pressure steam
turbine, and the first low pressure steam valve is closed while the
clutch disengages the second low pressure steam turbine from the
first low pressure steam turbine.
5. The power generation system as in claim 4 wherein the first
valve is an isolation valve.
6. The power generation system as in claim 1 wherein the at least
one elevated steam turbine includes a high pressure steam turbine
receiving high pressure steam and an intermediate steam turbine
receiving steam exhausted from the high pressure steam turbine,
wherein steam exhausted from the intermediate steam turbine is
applied as the low pressure steam for the low pressure steam
turbine.
7. The power generation system as in claim 1 wherein the clutch is
a planetary clutch.
8. The power generation system as in claim 1 wherein the first
position of the clutch is an open position and the second position
of the clutch is a closed position.
9. A power generation system comprising: a high pressure steam
turbine receiving high pressure steam and exhausting steam at an
intermediate pressure; an intermediate steam turbine receiving
steam exhausted from the high pressure steam turbine and exhausting
low pressure steam; a low pressure steam turbine receiving low
pressure steam exhausted from the intermediate steam turbine, and a
drive shaft for the low pressure steam turbine connected to a
clutch and the clutch is releasably coupled to a power generator,
wherein the clutch has a first position in which power from the low
pressure steam turbine is applied to the power generator and a
second position in which power from the low pressure steam turbine
is not applied to the generator.
10. The power generation system in claim 9 further comprising a
first low pressure steam valve in a conduit for low pressure steam
flowing to the low pressure steam turbine and a second low pressure
steam valve in a conduit for low pressure steam flowing to a steam
process extraction device, wherein the first low pressure steam
valve is open while the second low pressure steam valve is closed,
and the first low pressure steam valve is closed while the second
low pressure steam valve is open.
11. The power generation system in claim 10 wherein the low
pressure steam turbine includes a first low pressure steam turbine
and a second low pressure steam turbine, and the clutch engages and
disengages the second low pressure steam turbine from the first low
pressure steam turbine.
12. The power generation system in claim 11 further comprising a
first low pressure steam valve in a conduit for the low pressure
steam flowing to the second low pressure steam turbine, wherein the
first low pressure steam valve is open while the clutch engages the
second low pressure steam turbine to the first low pressure steam
turbine, and the first low pressure steam valve is closed while the
clutch disengages the second low pressure steam turbine.
13. The power generation system in claim 9 wherein the drive shaft
is coupled to a drive shaft for the high pressure steam turbine and
a drive shaft for the low pressure steam turbine.
14. A method for power generation using a generator, an elevated
pressure steam turbine, a low pressure steam turbine and a clutch
coupled to a drive shaft of the low pressure steam turbine, the
method comprising: applying low pressure steam to the low pressure
steam turbine; driving the generator by the low pressure steam
turbine while the clutch is closed, and opening the clutch to
disengage the low pressure steam turbine from the generator.
15. The method in claim 14 further comprising terminating the
application of low pressure steam to the low pressure steam turbine
while the clutch is open.
16. The method in claim 14 further comprising closing a first valve
to terminate the application of low pressure steam to the low
pressure steam turbine and opening a second valve to direct low
pressure steam to an external process, wherein the first valve is
closed and the second valve is open while the clutch is open.
17. The method as in claim 14 wherein the low pressure steam
turbine is a first low pressure steam turbine and the method
further comprises: applying low pressure steam to the second low
pressure steam turbine during the application of low pressure steam
to the first low pressure steam turbine; driving the generator by
the second low pressure steam turbine in addition to the driving of
the generator by the first low pressure steam turbine, and
continuing to drive the generator by the second low pressure steam
turbine, while the clutch is open.
18. The method as in claim 17 wherein the opening of the clutch
disengages a drive shaft for the first low pressure steam turbine
from a drive shaft for the second low pressure steam turbine.
19. The method as in claim 14 further comprising applying elevated
pressure steam to an elevated pressure steam turbine and driving
the generator with the elevated pressure steam turbine while the
clutch is open.
20. The method as in claim 14 further comprising, after the opening
of the clutch, closing the clutch to engage the low pressure steam
turbine to drive the generator.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to power generation systems
including multiple steam turbines and, particularly, to coupling
steam turbines to such systems.
[0002] Large power generator systems often employ two or more steam
turbines to drive generators to produce power. The steam turbines
are conventionally coupled together to drive power generators. For
example, multiple steam turbines may be connected by a common shaft
that drives a generator. A cross compound turbine arrangement has
two or more generators each driving one or more steam turbines. A
power generation system having cross-compound turbines typically
has a generator for the high pressure and intermediate steam
turbine, and a separate generator for the low pressure steam
turbines.
[0003] The power demand loads applied to power generator systems
often vary during the course of a day, weeks, and months. It is
desirable for power generation systems to adapt to the variations
in the power generation demands. Specifically, there is a need for
power generator systems to engage and disengage its steam turbines
depending on the power demand.
BRIEF DESCRIPTION OF THE INVENTION
[0004] A system of valves and a clutch has been developed to
disengage and engage one or more steam turbine sections from a
power generation system. For example, the system may include a
planetary clutch between a low pressure steam turbine and other
steam turbines, and associated valves to open and turn off the
steam flow to the low pressure steam turbine depending on whether
the clutch engages or disengages the low pressure steam turbine.
The low pressure steam turbine may be disengaged while the demand
for power from the generator is low and may be engaged when the
demand for power is high.
[0005] A power generation system including: at least one elevated
steam turbine receiving input steam at an elevated pressure and
exhausting steam as low pressure steam; a low pressure steam
turbine receiving low pressure steam exhausted from the elevated
steam turbine, and a drive shaft for the low pressure steam turbine
connected to a clutch which is reasonably coupled to a power
generator, wherein the clutch has a first position in which power
from the low pressure steam turbine is applied to the power
generator and a second position in which power from the low
pressure steam turbine is not applied to the generator.
[0006] The at least one elevated steam turbine may include a high
pressure steam turbine receiving high pressure steam and an
intermediate steam turbine receiving steam exhausted from the high
pressure steam turbine, wherein steam exhausted from the
intermediate steam turbine is applied as the low pressure steam for
the low pressure steam turbine. The power generation system may
further include a first low pressure steam valve in a conduit for
low pressure steam flowing to the low pressure steam turbine and a
second low pressure steam valve in a conduit for low pressure steam
flowing to a steam process extraction device, wherein the first low
pressure steam valve is open while the second low pressure steam
valve is closed, and the first low pressure steam valve is closed
while the second low pressure steam valve is open.
[0007] A power generation system has been developed comprising: a
high pressure steam turbine receiving high pressure steam and
exhausting steam at an intermediate pressure; an intermediate steam
turbine receiving steam exhausted from the high pressure steam
turbine and exhausting low pressure steam; a low pressure steam
turbine receiving low pressure steam exhausted from the
intermediate steam turbine, and a drive shaft for the low pressure
steam turbine connected to a clutch and the clutch is releasably
coupled to a power generator, wherein the clutch has a first
position in which power from the low pressure steam turbine is
applied to the power generator and a second position in which power
from the low pressure steam turbine is not applied to the
generator.
[0008] A method has been developed for power generation using a
generator, an elevated pressure steam turbine, a low pressure steam
turbine and a clutch coupled to a drive shaft of the low pressure
steam turbine, the method comprising: applying low pressure steam
to the low pressure steam turbine; driving the generator by the low
pressure steam turbine while the clutch is closed, and opening the
clutch to disengage the low pressure steam turbine from the
generator.
[0009] The method may further comprise closing a first valve to
terminate the application of low pressure steam to the low pressure
steam turbine and opening a second valve to direct low pressure
steam to a process extraction device, wherein the first valve is
closed and the second valve is open while the clutch is open. In
the method, the low pressure steam turbine may be a first low
pressure steam turbine and the method further comprises: applying
low pressure steam to the second low pressure steam turbine during
the application of low pressure steam to the first low pressure
steam turbine; driving the generator by the second low pressure
steam turbine in addition to the driving of the generator by the
first low pressure steam turbine, and continuing to drive the
generator by the second low pressure steam turbine, while the
clutch is open. Further, the opening of the clutch may disengage a
drive shaft for the first low pressure steam turbine from a drive
shaft for the second low pressure steam turbine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic diagram of a power generation system
including steam turbines having a clutch coupling.
[0011] FIG. 2 is a schematic diagram of another power generation
system similar to the power generation system shown in FIG. 1,
except the other system has a single pair of low pressure steam
turbines.
[0012] FIG. 3 is a schematic diagram of a cross-compound power
generation system having a first drive shaft(s) with a high
pressure steam turbine and an intermediate pressure steam turbine
that collectively drive a first generator, and a second drive
shaft(s) with low pressure steam turbines that drive a second
generator, wherein at least one of the low pressure steam turbines
is coupled by a clutch to the second drive shaft(s).
DETAILED DESCRIPTION OF THE INVENTION
[0013] FIG. 1 is a schematic diagram of a power generation system
10 including an electrical power generator 12 providing electricity
to a load 13, such as an electrical power utility or grid. The
generator is rotationally driven by a series of steam turbines
including a high pressure steam turbine (HP) 14, an intermediate
pressure steam turbine (IP) 16, a first pair of low pressure steam
turbines (LPA) 18 and a second pair of low pressure steam turbines
(LPB) 20. The generator and steam turbines are connected along a
common drive shaft assembly 22, which may be two or more coaxial
drive shafts coupled together.
[0014] High pressure steam, e.g., 2,500 pounds-per-square-inch
(psi) at a temperature of 1,050 degrees Fahrenheit (566 degrees
Celsius) from a boiler 13 is provided to the inlet of the high
pressure steam turbine. The reaction blades (buckets) and steam
passages in the high pressure steam turbine tend to be small as
compared to the reaction blades and steam passages in the
intermediate steam turbine. The reaction blades and steam passages
in the low pressure steam turbines tend to be larger than those in
the intermediate steam turbine. Steam exhausted from the high
pressure turbine passes through a reheater 15, e.g., to be reheated
to 1,050 degrees Fahrenheit and flows to the intermediate pressure
steam turbine. Low pressure steam, e.g., below 700 psi and
preferably at or below 200 psi and 700 degrees Fahrenheit (370
degrees Celsius), is provided from the intermediate pressure steam
turbine 16 through a low pressure steam conduit 30 to the low
pressure steam turbines 18, 20.
[0015] A planetary clutch 24 couples the drive shafts of the pair
of low pressure turbines (LPA, LPB) 18, 20. The planetary clutch
allows the second pair of low pressure turbines (LPB) to be
disengaged from the first pair of low pressure turbines (LBA) 18
and the other steam turbines and generator 12 in the power
generation system 10.
[0016] A first low pressure steam valve 32 and an isolation low
pressure steam valve 34 in the conduit 30 may be opened to allow
steam to flow to the second pair of low pressure steam turbines 20
and closed to shut off steam to the second pair of low pressure
steam turbines. The isolation valve 34 may have an open position
and a closed, and no intermediate positions. The first low pressure
steam valve may have open and closed positions, and intermediate
positions to regulate the flow of low pressure steam through the
conduit 30 and to the low pressure steam turbine. These low
pressure steam valves 32, 34 may be closed in conjunction with
opening the clutch 24 to disengage the drive shaft of the second
pair of low pressure steam turbines from the drive shafts of the
other steam turbines. The second pair of low pressure steam
turbines 18 may be disengaged while the load 13 is relatively low
and power from the second pair of steam turbines is not needed.
[0017] FIG. 2 shows a power generation system 40 similar to the
power generation system 10, except with respect to the low pressure
steam turbines 42. System 40 has a single pair of low pressure
steam turbines 42 having a drive shaft 44 coupled to a planetary
clutch 46 that engages the drive shaft 22 of the intermediate
pressure steam turbine 16. A first valve 48 governs the flow of
steam to the pair of low pressure steam turbines 42. A second valve
50 directs steam to an external process 52, while the first valve
is closed.
[0018] In operation, the first valve is open and the second valve
is closed when the clutch is closed to couple the drive shaft 44 of
the low pressure steam turbines 42 to drive the generator 12 in
cooperation with the high pressure steam turbine 14 and the
intermediate pressure steam turbine 16. When the load demand on the
generator 12 is low, the low pressure steam turbines 42 are
disengaged by opening the clutch, closing the first valve 48 to
shut off the flow of low pressure steam to the low pressure steam
turbines and opening the second valve 50 to direct the low pressure
steam to a process extraction device 52, such as steam
recirculation conduits extending through a boiler providing steam
for the high pressure steam turbine or an other steam heated or
driven device nearby the low pressure steam turbine.
[0019] FIG. 3 is a schematic diagram of a cross-compound power
generation system 60 having a first drive shaft(s) 62 with a high
pressure steam turbine 14 and an intermediate pressure steam
turbine that collectively drive a first generator 64. The low
pressure steam turbines include a first pair of low pressure steam
turbines 66 and a second pair of low pressure steam turbines 68 are
connected to a common drive shaft(s) 70 that drive a second
generator 72. A planetary clutch 74 allows the first pair of low
pressure steam turbines 66 to be disengaged from the second pair of
low pressure steam turbines and the generator. The first pair of
low pressure steam turbines may be disengaged when there is a low
load demand on the second generator 72.
[0020] In conjunction with the operation of the clutch 74, valves
are operated to control the flow of low pressure steam from the
intermediate pressure steam turbine 16 to the low pressure steam
turbines 66, 68 and to a process extraction device 52. First and
second steam valves 76, 78 turn on and turn off low pressure steam
to each, respectively, of the first and second pairs of low
pressure steam turbines. Both steam valves 76, 78 are open to allow
steam to flow to both pairs of low pressure steam turbines 66, 68,
while the clutch is closed so that the common drive shaft(s) 70 are
coupled together and both pairs of low pressure steam turbines 66,
68 drive the second generator 72. To disengage the first pair of
low pressure steam turbines, the clutch 74 is opened and the first
steam valve 76 is closed to shut off low pressure steam to the
first pair of low pressure steam turbines 66. When the first steam
valve 76 is closed, the second steam valve 78 remains open and the
third steam valve 80 is opened to direct low pressure steam to the
process extraction device.
[0021] The clutch and low pressure steam valves disclosed herein
may be arranged to disengage low pressure steam turbines during
certain operational conditions, such as when the load demand on the
generator(s) is well below the capacity of the steam turbines that
drive the generator(s). When the load is below capacity, the clutch
and low pressure steam valves may be operated to disengage at least
one low pressure steam turbine from the power generation system.
The efficiency of the system is increased by allowing the remaining
low pressure steam turbine(s), if any, to operate at a higher power
output and hence higher capacity than if all of the low pressure
steam turbines were engaged and operating at below capacity and
hence lower efficiency. The disengaged steam turbine can be idled
so that it is ready to be reengaged to the power system when
needed, such as when the load demand increases.
[0022] While the invention has been described in connection with
what is presently considered to be the most practical and preferred
embodiment, it is to be understood that the invention is not to be
limited to the disclosed embodiment, but on the contrary, is
intended to cover various modifications and equivalent arrangements
included within the spirit and scope of the appended claims.
* * * * *