U.S. patent application number 10/569564 was filed with the patent office on 2006-11-30 for steam power plant.
This patent application is currently assigned to SIEMENS AKTIENGESELLSCHAFT. Invention is credited to Georg Haberberger, Christoph Kail.
Application Number | 20060266040 10/569564 |
Document ID | / |
Family ID | 29265806 |
Filed Date | 2006-11-30 |
United States Patent
Application |
20060266040 |
Kind Code |
A1 |
Haberberger; Georg ; et
al. |
November 30, 2006 |
Steam power plant
Abstract
An inventive steam power plant comprises at least one steam
turbine and a steam generator, whereby a combustion chamber, in the
direction of the flow of steam, is mounted after a first turbine
stage and before a second turbine stage of the steam turbine, and
the flow of steam inside a combustion chamber can be heated by
mixing it with a hot gas that can be produced inside said
combustion chamber.
Inventors: |
Haberberger; Georg;
(Bubenreuth, DE) ; Kail; Christoph; (Dortmund,
DE) |
Correspondence
Address: |
SIEMENS CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
170 WOOD AVENUE SOUTH
ISELIN
NJ
08830
US
|
Assignee: |
SIEMENS AKTIENGESELLSCHAFT
Munchen
DE
|
Family ID: |
29265806 |
Appl. No.: |
10/569564 |
Filed: |
July 26, 2004 |
PCT Filed: |
July 26, 2004 |
PCT NO: |
PCT/EP04/08348 |
371 Date: |
August 17, 2006 |
Current U.S.
Class: |
60/645 |
Current CPC
Class: |
F01K 25/005 20130101;
Y02E 20/344 20130101; Y02E 20/34 20130101 |
Class at
Publication: |
060/645 |
International
Class: |
F01K 13/00 20060101
F01K013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 27, 2003 |
DE |
203 13 279.3 |
Claims
1-4. (canceled)
5. A steam power plant comprising; at least one steam turbine; a
fired steam generator; and a combustion chamber that is disposed
after a first turbine stage and before a second turbine stage of
the steam turbine in the direction of the flow of steam and the
flow of steam in the combustion chamber is heated by mixing it with
a hot gas that is produced in the combustion chamber.
6. The steam power plant according to claim 5, wherein hydrogen or
a hydrocarbon is supplied as fuel to the firing facility.
7. The steam power plant according to claim 5, wherein hydrogen and
a hydrocarbon is supplied as fuel to the firing facility.
8. The steam power plant according to claim 7, wherein the
hydrocarbon is methane.
9. The steam power plant according to claim 5, wherein a gas
containing oxygen and/or air is supplied to the firing facility to
produce a combustion atmosphere in the combustion chamber.
10. The steam power plant according to claim 5, wherein the gas
contains pure oxygen.
11. The steam power plant according to claim 5, wherein combustion
products occurring are removed from the flow of steam by a
condenser connected downstream from the steam turbine.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is the US National Stage of International
Application No. PCT/EP2004/008348, filed Jul. 26, 2004 and claims
the benefit thereof. The International Application claims the
benefits of German Patent application No. 20313279.3 DE filed Aug.
27, 2003, both of the applications are incorporated by reference
herein in their entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a steam power plant with at least
one steam turbine and a fired steam generator.
BACKGROUND OF THE INVENTION
[0003] With known steam power plants operating steam for a steam
turbine is generally generated in a fired steam generator, with the
energy contained in a hot gas being transferred to one or more heat
exchangers, which are supplied with water, such that operating
steam can be generated by heating this water, or which are supplied
with steam such that superheating of the steam can be achieved by
means of a last-mentioned heat exchanger; such superheating takes
place in known steam turbines for example between a high-pressure
stage and a medium-pressure stage of the steam turbine, with the
steam leaving the high-pressure stage being superheated by means of
an intermediate superheating heating surface disposed in the steam
generator and being supplied to the medium-pressure stage.
[0004] Such intermediate superheating of the steam for example
contributes to the greater efficiency of the steam turbine.
[0005] With known steam power plants the thermal energy for the
generation and/or intermediate superheating of steam is supplied by
means of heat exchanger surfaces, which are disposed in the fired
generator, for example a coal, oil or biomass-fired or generally
fossil or nuclear-fired steam boiler and come into contact with a
hot gas supplied in the steam generator. The heated heat exchanger
surfaces in turn transfer their thermal energy to water and/or
steam, which is/are supplied inside the element formed by a heat
exchanger surface. Heating therefore takes place by means of a heat
transfer from the hot gas to the heat exchanger surface and from
the heat exchanger surface to the medium to be heated.
[0006] Since with the heat exchangers known from the prior art,
which are used in steam generators of known steam power facilities,
the energy from a hot gas is transferred to the medium to be heated
by means of a material of the heat exchanger surface heated by the
hot gas, the quantity of energy that can be transferred to the
medium to be heated, for example water and/or steam, is limited by
the material characteristics of the heat exchanger surface.
[0007] With known steam power facilities the permissible steam
temperatures are therefore limited, since the heat exchanger
surface transferring the thermal energy cannot be heated up to an
arbitrary high temperature due to its material characteristics and
the thermal load limits associated therewith.
[0008] The thermal transfer of hot gas to the medium to be heated
is also subject to a delay, essentially due to the time required to
heat up the heat exchanger surface.
SUMMARY OF THE INVENTION
[0009] The object of the invention is therefore to specify a steam
power plant with at least one steam turbine and a steam generator,
which can be used in a flexible manner and in particular overcomes
the disadvantages of the prior art as mentioned above.
[0010] According to the invention the object is achieved by a steam
power plant, comprising at least one steam turbine and a fired
steam generator, whereby a combustion chamber is disposed after a
first turbine stage and before a second turbine stage of the steam
turbine in the direction of the flow of steam and the flow of steam
in the combustion chamber can be heated by mixing it with a hot gas
that can be produced in said combustion chamber.
[0011] The invention is thereby based on the consideration that the
thermal transfer of a hot gas to a medium to be heated is subject
to fewer limitations compared with the prior art, if the energy
transfer to the medium to be heated does not use a heat exchanger
surface.
[0012] This is achieved with the invention in that the flow of
steam to be heated is introduced directly into a combustion chamber
and is mixed directly with the hot gas there.
[0013] This claimed internal additional firing system can be used
after the steam generator and before the steam turbine in the
direction of the flow of steam, in other words to superheat live
steam, or even to superheat steam which has already transferred
some of its energy in a turbine stage and is supplied to a further
turbine stage after a claimed superheating process.
[0014] Higher steam temperatures can be achieved with a claimed
steam power plant than with the prior art, which can contribute to
the greater efficiency of the steam power plant.
[0015] If the additional firing system implemented by means of the
combustion chamber is disabled or fails in a claimed steam power
plant, the steam power plant can continue to operate in the manner
of a known steam power plant.
[0016] Hydrogen and/or a hydrocarbon, in particular methane, can
advantageously be supplied to the combustion chamber as fuel.
[0017] In particular the fuel comprises carbon and/or hydrogen.
[0018] The use of hydrogen as fuel primarily has the advantage
that--if the hydrogen is produced as is often standard practice by
reforming or gasification from a hydrocarbon--any carbon dioxide
occurring can be retained during production of the hydrogen in the
process of reforming or gasifying a hydrocarbon, with a
comparatively low energy outlay, thus preventing the formation of
an acid steam mixture inside the steam turbine and/or other
components of the steam power plant from the outset.
[0019] To achieve particularly efficient firing of the combustion
chamber, a gas containing oxygen, in particular pure oxygen and/or
air, can advantageously be supplied to the firing facility to
produce a combustion atmosphere.
[0020] This embodiment of the invention takes into account the
requirement that fuel combustion is only possible in a suitable
combustion atmosphere. Particularly efficient combustion can be
achieved by supplying pure oxygen, as compared with air this
contains no components that might tend to hinder combustion, which
would for example have to be separated before combustion in an air
separator, to create a suitable combustion atmosphere.
[0021] In a further preferred embodiment of the invention the
combustion products that occur can be removed from the flow of
steam by means of a condenser connected downstream from the steam
turbine.
[0022] Combustion products result from almost all combustion
processes and most have to be removed, as they can be deposited in
the combustion chamber or other components, particularly after a
long operating period, and restrict its function.
[0023] If hydrocarbon for example is burned as fuel in an
atmosphere of pure oxygen in a claimed steam power plant, the
combustion products water and carbon dioxide at least result. These
combustion products are carried along by the flow of steam and
routed to the condenser. A condenser is generally present anyway in
known steam power plants, so that a separate condenser that is
suitable for removing combustion products does not have to be
provided for the purposes of the invention.
[0024] When the steam, which contains the combustion products as a
mixture of water and carbon dioxide, is cooled, the water element
largely condenses, leaving almost pure, gaseous carbon dioxide,
which can be removed from the condenser and stored for example.
[0025] As already mentioned above, when hydrogen, which is produced
by reforming or gasifying a hydrocarbon, is used as fuel, any
carbon dioxide occurring can be removed before the fuel is
introduced into the combustion chamber, such that almost no carbon
dioxide results as a combustion product during combustion in this
instance.
[0026] The internal additional firing implemented by means of the
combustion chamber of a claimed steam power plant can be made
available very quickly during operation of the steam turbine. It
only requires ignition of the fuel introduced into the combustion
chamber; the time required in particular to heat up known heat
exchanger surfaces in particular is not required.
[0027] A claimed steam power plant also has the advantage that
combustion products and/or waste gas do not necessarily have to be
removed from the combustion chamber by means of a separate
discharge facility, as they are carried along with the flow of
steam and can be extracted at another point in the steam circuit,
for example the said condenser. Also a higher steam temperature can
be achieved with the invention, without having to change the design
of the steam generator.
[0028] A claimed steam power plant can in particular also be used
to supply energy in peak load periods or to boost the system
frequency of an electrical energy supply network; a claimed steam
power plant allows fast output regulation and can be used in a very
flexible manner.
BRIEF DESCRIPTION OF THE DRAWING
[0029] An exemplary embodiment of the invention is shown in the
FIGURE which follows, in which:
[0030] FIGURE shows a claimed steam power plant.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The FIGURE shows a claimed steam power plant 1, having a
steam turbine 3 coupled to a generator 21 and a fired steam
generator 5.
[0032] The steam turbine 3 has three stages, a first turbine stage
11, a second turbine stage 13 and a third turbine stage 15, which
are configured as a high-pressure stage, a medium-pressure stage
and a low-pressure stage.
[0033] In the present exemplary embodiment in the FIGURE the steam
generator 5 is a boiler fired by coal 27, to which combustion air
29 is supplied to maintain the coal-firing process.
[0034] A heating surface 37 is disposed in the area of the hot end
of the steam generator 5 and an intermediate superheating heating
surface 35 is disposed in a lower temperature area.
[0035] The heating surface 37 serves to heat a water supply 24 from
a water supply tank 23 in the steam generator 5 such that operating
steam can be supplied to the first turbine stage 11.
[0036] After partial expansion in the first turbine stage 1 the
steam is subjected to intermediate superheating by means of the
intermediate superheating heating surface 35. A flow of steam 17
leaves the intermediate superheating heating surface 35 in
direction 9 and is routed to a firing facility. During this process
the flow of steam 17 is heated in a combustion chamber 19 by means
of a fuel 33 and the introduction of oxygen 31, with the flow of
steam 17 in the combustion chamber 19 mixing with the hot gas that
results in the combustion chamber 19 during combustion of the fuel
33.
[0037] The thermal transfer from the hot gas to the flow of steam
17 therefore takes place directly by mixing, without a material,
for example a heat exchanger surface, being provided for the
thermal transfer.
[0038] It is also possible to use air instead of oxygen 31 to
produce a suitable combustion atmosphere, with the air optionally
being split into oxygen and residual gas by means of an air
separator before introduction into the combustion chamber.
[0039] A hydrocarbon, in particular methane, or hydrogen can be
used as the fuel 33.
[0040] The flow of steam 17 heated by means of the combustion
chamber 19 is supplied to the second turbine stage 13, where it
converts at least some of the energy contained in it to mechanical
work. The thus further expanded steam leaves the second turbine
stage 13 and is routed to the third turbine stage 15, where the
energy still present in the steam is converted as efficiently as
possible to mechanical energy.
[0041] The expanded steam leaves the third turbine stage 15 as a
water/steam mixture and is routed to a condenser 25, where the
steam element still present is condensed to water.
[0042] This water collecting in the condenser 25 is supplied to the
water supply tank 23 as condensate 26.
[0043] Combustion products 39, which result during combustion in
the combustion chamber 19, can be removed from the condenser
25.
[0044] As combustion takes place within the flow of steam 17 in the
combustion chamber 19, the combustion products 39 are carried along
by the flow of steam 17 in the steam circuit and removed from the
condenser 25 according to this embodiment of the invention.
[0045] If a hydrocarbon is combusted with oxygen 31 as the fuel 33
for example, the combustion products 39 comprise water and carbon
dioxide. This water/carbon dioxide mixture is carried along by the
flow of steam 17 and can be removed from the condenser 25, as the
water element is largely condensed during cooling of the
water/carbon dioxide mixture, leaving a gas in the form of almost
pure gaseous carbon dioxide, which can then be carried away and
stored for example.
* * * * *