U.S. patent application number 14/397624 was filed with the patent office on 2015-03-19 for sound damper for evaporation channels in steam power plants with air condensers.
The applicant listed for this patent is SIEMENS AKTIENGESELLSCHAFT. Invention is credited to Stephan Minuth.
Application Number | 20150075166 14/397624 |
Document ID | / |
Family ID | 48184179 |
Filed Date | 2015-03-19 |
United States Patent
Application |
20150075166 |
Kind Code |
A1 |
Minuth; Stephan |
March 19, 2015 |
SOUND DAMPER FOR EVAPORATION CHANNELS IN STEAM POWER PLANTS WITH
AIR CONDENSERS
Abstract
A steam turbine unit, in particular for a steam power plant,
comprising a steam turbine and a condenser connected to the steam
turbine via an evaporation channel is provided. According to the
following, a sound damper, particularly a low-frequency sound
damper, is acoustically coupled to the evaporation channel.
Inventors: |
Minuth; Stephan; (Mulheim
A.D. Ruhr, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SIEMENS AKTIENGESELLSCHAFT |
80333 MUNCHEN |
|
DE |
|
|
Family ID: |
48184179 |
Appl. No.: |
14/397624 |
Filed: |
April 18, 2013 |
PCT Filed: |
April 18, 2013 |
PCT NO: |
PCT/EP2013/058087 |
371 Date: |
October 28, 2014 |
Current U.S.
Class: |
60/694 |
Current CPC
Class: |
F28B 9/02 20130101; F01K
7/16 20130101; F01K 9/003 20130101; F05D 2260/96 20130101; F28F
2265/28 20130101; F01D 25/30 20130101; F28B 1/02 20130101 |
Class at
Publication: |
60/694 |
International
Class: |
F01D 25/30 20060101
F01D025/30; F28B 9/02 20060101 F28B009/02; F01K 9/00 20060101
F01K009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 30, 2012 |
DE |
10 2012 207 176.8 |
Claims
1-10. (canceled)
11. A steam turbine unit having at least one steam turbine and a
condenser which is connected to the steam turbine via a waste steam
duct, wherein a silencer embodied as a reflection silencer is
coupled acoustically to the waste steam duct and the silencer has
multiple reflection chambers of different sizes and/or different
volumes, which reflection chambers are each configured for
filtering a very specific frequency range or frequency band.
12. The steam turbine unit as claimed in claim 11, characterized in
that the silencer is a low-frequency silencer.
13. The steam turbine unit as claimed in claim 11, characterized in
that the silencer is configured to damp frequencies below 500 Hz,
in particular between 40 Hz and 500 Hz, more particularly between
60 Hz and 250 Hz.
14. The steam turbine unit as claimed in claim 11, characterized in
that the silencer is arranged in the waste steam duct such that
waste steam from the steam turbine can flow through it.
15. The steam turbine unit as claimed in claim 11, characterized in
that the silencer has a drainage device, in particular a drainage
device arranged in a chamber of the silencer.
16. The steam turbine unit as claimed in claim 11, characterized in
that the silencer is coupled acoustically to a hotbox, connected to
the steam turbine, of the steam turbine unit.
17. The steam turbine unit as claimed in claim 11, characterized in
that the silencer is coupled acoustically to a further silencer, in
particular in that the silencer is an interference silencer and the
further silencer, coupled acoustically to the interference
silencer, is an absorption silencer.
18. The steam turbine unit as claimed in claim 11, characterized in
that the steam turbine has multiple single- or multiple-flow
turbine sections, in particular a single- or multiple-flow
low-pressure, intermediate-pressure and/or high-pressure turbine
section, each of which is connected to the condenser via a separate
waste steam duct, wherein one or more silencer(s) is/are coupled
acoustically to one, several or all of these waste steam ducts, or
several or all of these turbine sections are connected to the
condenser via a central waste steam duct, wherein the silencer is
coupled acoustically to the central waste steam duct.
19. The steam power plant having a steam turbine unit as claimed in
claim 11, characterized in that the silencer is arranged within a
machine casing.
20. The steam power plant as claimed in claim 11, characterized in
that the steam power plant is a coal-fired power plant, an
oil-fired power plant or a gas-and-steam combined-cycle power
plant.
21. A silencer for use in a steam turbine unit having at least one
steam turbine and a condenser which is connected to the steam
turbine via a waste steam duct: said silencer embodied as a
reflection silencer is coupled acoustically to the waste steam duct
and the silencer has multiple reflection chambers of different
sizes and/or different volumes, which reflection chambers are each
configured for filtering a very specific frequency range or
frequency band.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to PCT Application No.
PCT/EP2013/058087, having a filing date of Apr. 18, 2013, based off
of DE 102012207176.8 having a filing date of Apr. 30, 2012, the
entire contents of which are hereby incorporated by reference.
FIELD OF TECHNOLOGY
[0002] The following relates to a steam turbine unit, in particular
for a steam power plant, having a steam turbine and a condenser
which is connected to the steam turbine via a waste steam duct.
BACKGROUND
[0003] Steam power plants, otherwise known as thermal power plants,
are extensively known, for example from
http://de.wikipedia.org/wiki/Dampfkraftwerk (retrieved Apr. 20,
2012).
[0004] A steam power plant is a type of power plant for generating
electricity from fossil fuels, in which thermal energy from steam
is converted into kinetic energy in a steam turbine and is further
converted into electrical energy in a generator.
[0005] In such a steam power plant, the steam required for
operating the steam turbine is first generated in a boiler from
(feed) water, which generally has been previously purified and
prepared. Further heating the steam in a superheater increases the
temperature and specific volume of the steam.
[0006] From the boiler, the steam flows via pipes into the steam
turbine, where it gives off part of its previously absorbed energy
as kinetic energy to the steam turbine. A generator is coupled to
the steam turbine and converts mechanical power to electrical
power.
[0007] Thereafter, the expanded and cooled steam flows out of the
steam turbine via a waste steam line or a waste steam duct into the
condenser, where it condenses by transfer of heat to the
surroundings and collects as liquid water.
[0008] Via condensate pumps and through preheaters, the water is
held in a feed water container and is then once again supplied to
the boiler by means of a feed pump, thus closing a circuit.
SUMMARY
[0009] A distinction is drawn between various types of steam power
plants, such as coal-fired power plants, oil-fired power plants, or
also gas-and-steam combined-cycle power plants (COGAS power
plants), which differ in their different methods for generating
steam.
[0010] A COGAS power plant is described for example in
http://de.wikipedia.org/wiki/Gas-und-Dampf-Kombikraftwerk
(retrieved Apr. 20, 2012).
[0011] A COGAS power plant of this type is a power plant in which
the principles of a gas turbine power plant and of the steam power
plant are combined. A gas turbine serves here as a heat source for
a downstream waste heat boiler which in turn serves as a steam
generator for the steam turbine.
[0012] It is further known that turbomachines, such as the steam
turbines, produce relatively high pressure emissions and/or sound
emissions which, in addition to vibrations and structure-relevant
malfunctions, can also lead to (noise) disturbance in the
surroundings of the turbomachine.
[0013] For example, dominant pressure/sound sources in a steam
turbine are typically generated at a rotor disk, caused by the high
speed of the fluids flowing through these regions and by an
interaction between rotor components and stator components.
[0014] It is further known in this case that these emerging
pressure/sound sources generate complex, dynamic,
three-dimensional, rotating and/or pulsating pressure fields, whose
pressure/sound waves propagate, via the fluid or flow medium, in
adjacent flow spaces both downstream and upstream of the specified
point of origin, such as the waste steam ducts coupled fluidically
to the steam turbine.
[0015] In many such steam power plants having described steam
turbines, an elevated sound pressure level, in particular at low
frequency ranges, for example at frequencies<500 Hz, was
measured in the waste steam duct connecting the steam turbine to
the condenser.
[0016] This low-frequency sound is transmitted further, through or
via the waste steam duct, into the condenser. This acts as a
loudspeaker and transmits the sound further into the surroundings
of the condenser or steam power plant.
[0017] This can lead to high noise load or noise pollution in the
surroundings of the power plant, for example in residential areas
adjacent to the steam power plant. In particular, low-frequency
noise is also experienced as an unpleasant rumbling.
[0018] If the sound emissions of the steam power plant exceed sound
protection limit values, this can in the worst case lead to the
steam power plant losing its operating permit.
[0019] Low-frequency sound, as can be observed in the waste steam
ducts, also has the disadvantage that it cannot be effectively
blocked or damped by means of insulation, for example on the waste
steam duct.
[0020] Low-frequency sound also excites eigenfrequencies of
adjacent components. This can lead to damage to components.
[0021] Silencers, i.e. generally devices for reducing sound
emissions, are generally known. There are several basic designs for
silencers, which reduce the generated sound power on the basis of
various mechanisms. In general, absorption silencers or
interference/reflection silencers--hereinafter designated just as
reflection silencers--are used.
[0022] Such a reflection silencer contains multiple, for example
four, chambers in order to make use of the principle of acoustic
reflection.
[0023] Multiple passes through the chamber internal spaces produces
an averaging of sound pressure amplitudes, which results in a
reduction of sound pressure peaks.
[0024] The acoustic reflections are generated in the reflection
silencer by baffles, cross-sectional widenings and narrowings.
[0025] In the reflection silencer, principally the low frequencies
are damped by the acoustic reflection.
[0026] An absorption silencer contains a porous material, in
general rockwool, glass wool or glass fiber, which partially
absorbs sound energy, that is to say converts it into heat.
[0027] The effect of the sound absorption is then reinforced by the
multiple reflection.
[0028] In the absorption silencer, principally the upper or higher
frequencies are damped by absorption.
[0029] A low-frequency silencer embodied as an interference
silencer or low-frequency silencer is known from HOBATHERM.RTM.,
G:\VERKAUF\Technischer Ordner\Technischer Ordner 2008.doc, 3.4
Tiefton-Schalldampfer.
[0030] Embodiments of the invention are based on the aspect of
creating a steam turbine unit having at least one steam turbine and
a condenser which is connected to the steam turbine via a waste
steam duct, which steam turbine unit overcomes the described
drawbacks of the prior art. In particular, the embodiments of the
invention are based on the aspect of creating such a steam turbine
unit which can be operated in a manner which is safe for the
components and with low sound emissions, and which can be produced
cost-effectively and easily.
[0031] The aspect is achieved with a steam turbine unit having the
features according to the independent claim.
[0032] The steam turbine unit corresponding to embodiments of the
invention have at least one steam turbine and a (waste steam)
condenser which is connected to the steam turbine via a waste steam
duct or waste steam line, both referred to in the following simply
as waste steam duct.
[0033] In the steam turbine unit according to embodiments of the
invention, it is further provided that a silencer is coupled
acoustically to the waste steam duct.
[0034] "Coupled acoustically" is to be understood as meaning that
sound or sound waves occurring in the waste steam duct can enter
the silencer for sound damping or sound attenuation therein.
[0035] More simply, or in other words, waste steam supplied from
the steam turbine to the condenser via the waste steam duct is,
according to embodiments of the invention, guided in or through the
silencer arranged in the waste steam duct, in which sound pressure
levels occurring in the waste steam are damped or attenuated.
[0036] Thus, by the use according to embodiments of the invention
of the silencer, the in a simple or constructively simple and
effective manner, damping of sound occurring in the waste steam
duct. The high noise load or noise pollution in the surroundings of
the steam turbine unit can thereby be reduced, and sound protection
limit levels can be observed.
[0037] In addition, vibrations and structure-relevant
malfunctions--and consequently damage to components--which are
caused by pressure emissions and/or sound emissions, can be reduced
by means of embodiments of the invention.
[0038] Preferred refinements of embodiments of the invention also
emerge from the dependent claims.
[0039] One preferred refinement provides that the silencer is a
low-frequency silencer, in particular configured as an interference
silencer or reflection silencer.
[0040] Such a low-frequency silencer, embodied as reflection
silencer, allows frequencies below 500 Hz to be damped in a
targeted manner, simply and effectively.
[0041] Since it has been established that in particular
low-frequency sound occurs in the waste steam duct, which
low-frequency sound is in addition experienced as an unpleasant
rumbling, such a low-frequency silencer accordingly represents a
most effective and efficient sound- or emission-protection measure
in the steam turbine unit.
[0042] According to one preferred refinement, the reflection
silencer has one or more reflection chambers which are each
configured for filtering a very specific range or band of
frequencies. It is thus possible to damp broad frequency
ranges.
[0043] Thus, for example, a reflection tube silencer having
multiple series-connected outer resonance chambers can be provided,
which resonance chambers function for example as lambda/2
resonators, lambda/4 resonators or Helmholtz resonators.
[0044] The reflection chambers may be embodied with or without any
absorption material, such as stainless steel or mineral wool. The
reflection chambers may furthermore be embodied as a welded
construction.
[0045] The reflection chambers may also each be equipped with a
liquid discharge or condensate discharge. Furthermore, cleaning
openings may also be provided in the reflection chambers.
[0046] One particularly preferred refinement provides that a
reflection chamber of such a reflection silencer is formed by an
inner sheet metal ring which is provided with longitudinal holes or
slits and which is enclosed concentrically by a further ring.
Multiple double rings of this type may be arranged in series in the
waste steam duct--either immediately adjacent to one another or at
a distance from one another--or may be coupled acoustically
therewith.
[0047] In order to configure the silencer to frequencies to be
damped--in the waste steam duct--it is preferably possible to carry
out a frequency analysis or a sound level measurement in the
third-octave spectrum of noises in the waste steam duct. Depending
on the result of this, a suitable silencer, for example a
reflection silencer for low-frequency sound or an absorption
silencer for higher-frequency sound, or a suitable or accordingly
adapted configuration of the silencer, for example reflection
chambers configured to certain frequencies or frequency bands in
the case of a reflection silencer, may then be used.
[0048] Another particularly preferred refinement provides that the
silencer is configured to damp low frequencies, for example below
500 Hz, in particular between 40 Hz and 500 Hz. Very particularly
preferred is a configuration of the silencer to damp frequencies
between 60 Hz and 250 Hz.
[0049] A particularly simple constructive embodiment is achieved by
the silencer being arranged in the waste steam duct such that waste
steam from the steam turbine can flow through it.
[0050] A further refinement provides that the silencer has a
drainage device. It is thereby possible to avoid liquid or
condensed waste steam, simply condensate for short, which is
precipitated from the waste steam, collecting in the silencer and
the latter thus being caused to vibrate.
[0051] This can be effected particularly simply if, in the case of
a reflection silencer having reflection cavities, these reflection
cavities are provided with drainage ducts or outflow bores.
[0052] What are termed hotboxes are often in each case arranged in
steam turbine units or in their waste steam ducts. By virtue of
such a hotbox, bypass steam can be fed into the waste steam duct.
One preferred refinement then provides in this case that the
silencer is coupled acoustically to such a hotbox.
[0053] A further preferred refinement provides that the silencer is
coupled acoustically to a further silencer, whereby both silencers
are then coupled acoustically to the waste steam duct. It is hereby
possible, in a manner which is very simple and efficient (in terms
of construction), to damp more frequencies and/or larger frequency
bands of the sound occurring in the waste steam duct.
[0054] Particularly preferably, the silencer may here be an
interference silencer--for damping the low-frequency sound--and the
further silencer, coupled acoustically to the interference
silencer, may be an absorption silencer--for damping the
higher-frequency sound.
[0055] It can also be provided that the steam turbine has multiple
sections or turbine sections. Thus, the steam turbine may be
provided with a low-pressure, an intermediate-pressure and/or a
high-pressure section. The turbine sections may be of single- or
multiple-flow, in particular two-flow, design.
[0056] Waste steam ducts which leave or lead away from these
sections or turbine sections--in each case to the condenser--may
thus be equipped with the silencer according to embodiments of the
invention. Alternatively, it is also possible in this case for
individual waste steam ducts or several or all of these waste steam
ducts to be combined into a "central" waste steam duct leading to
the condenser--and for the silencer according to embodiments of the
invention to be coupled acoustically to this "central" waste steam
duct.
[0057] In that context, the silencer may be arranged within a
machine casing which encloses the steam turbine at least partially
or even entirely. Alternatively, it can also be provided that the
silencer is arranged outside such a machine casing.
[0058] One preferred refinement provides that the steam turbine
installation according to embodiments of the invention are arranged
in a steam power plant or in a water/steam circuit created
there.
[0059] In that context, the steam power plant may be a coal-fired
power plant, an oil-fired power plant or a gas-and-steam
combined-cycle power plant.
[0060] The above description of advantageous configurations of
embodiments of the invention contain numerous features which are
reproduced in the individual subclaims, in some cases combined into
groups. However, a person skilled in the art will expediently also
consider these features individually and combine them into
appropriate further combinations.
[0061] The figures show exemplary embodiments of the invention
which will be explained in more detail below. Identical reference
signs in the figures denote technically identical elements.
BRIEF DESCRIPTION
[0062] Some of the embodiments will be described in detail, with
reference to the following figures, wherein like designations
denote like members, wherein:
[0063] FIG. 1 shows a water/steam circuit having a steam turbine
unit, consisting of a steam turbine and a condenser connected to
the steam turbine via waste steam ducts, in a steam power plant
according to one exemplary embodiment of the invention;
[0064] FIG. 2 shows a detailed representation of a low-frequency
silencer for a waste steam line or a waste steam duct in the steam
turbine unit or in the steam power plant according to the exemplary
embodiment of the invention; and
[0065] FIG. 3 shows a waste steam line, equipped with a
low-frequency silencer, in a steam turbine unit or in a steam power
plant according to the further exemplary embodiment of the
invention.
[0066] Exemplary embodiments: low-frequency silencer 2 for a waste
steam duct 24 in a steam power plant 100 with an (air/waste steam)
condenser 11.
DETAILED DESCRIPTION
[0067] FIG. 1 shows a water/steam circuit 18 of a coal-fired steam
power plant 100 with a steam turbine unit 1 consisting of a steam
turbine 22 and a condenser 11 connected to the steam turbine 22 via
waste steam ducts 24.
[0068] In this coal-fired power plant 100, in the following simply
steam power plant 100 for short, according to a conventional coal
firing, lignite or hard coal is ground and dried in a coal mill.
This coal is then blown into a combustion chamber 16 for a dust
firing facility, where it is completely burnt 17.
[0069] Heat thus released is taken up by a water-tube boiler, steam
generator 20 for short, and converts fed-in (feed) water 5 into
steam/high-pressure steam 6. The high-pressure steam 6 generated in
the steam generator 20 enters the high-pressure section 7 of the
steam turbine 22, where it performs mechanical work as it expands
and cools.
[0070] After leaving the high-pressure section 7, the high-pressure
steam 6 flows via a crossover line 23 into the two-flow
low-pressure section 8 of the steam turbine 22, where further
mechanical work is performed as the steam expands and cools to
waste steam pressure.
[0071] The generator 9 coupled to the steam turbine 22 then
converts the mechanical power into electrical power, which is
supplied to a grid 15 in the form of electrical current.
[0072] The waste steam 25 from the steam turbine 22 or from the
two-flow low-pressure (turbine) section 8 of the steam turbine 22
is supplied, via the two waste steam ducts 24, to the condenser 11
where the waste steam 25 condenses with the aid of the cooling
water 13 delivered through the cooling water circuit 10 by a
cooling water pump 12.
[0073] The resulting condensate or feed water 5 is supplied back to
the steam generator 20 by the condensate pump or feed water pump 4,
with heating in the preheater 14.
[0074] In order to damp high levels of low-frequency sound in the
two waste steam ducts, these are each coupled acoustically to a
low-frequency silencer 2, which is shown in more detail in FIG.
2.
[0075] To that end, as shown in FIG. 1, these two low-frequency
silencers 2, configured as reflection tube silencers--reflection
silencers 2 for short--which are particularly suited to damping
low-frequency sound emissions, are arranged in the two waste steam
ducts 24 through which the waste steam 25, flowing out of the
two-flow low-pressure turbine section 8, can flow.
[0076] FIG. 2 shows a detailed representation of the low-frequency
silencer 2 which is coupled acoustically to the two waste steam
ducts 24, or which is arranged in the two waste steam ducts 24 and
through which the waste steam 25 flows.
[0077] The low-frequency silencer 2 is designed as a reflection
silencer 2 having three reflection chambers 26, 27 and 28 which are
arranged in series in the flow direction 36 of the waste steam 25
and which function as lambda/2 resonators.
[0078] The reflection chambers 26, 27, 28, which are free from
absorption material or fibers, are formed by a smooth stainless
steel inner tube 29 through which the waste steam 25 flows and
which is enclosed concentrically by a jacket tube 30, also made of
stainless steel.
[0079] The interspace 31 thus formed between the two tubes 29 and
30 is divided or delimited by means of two separating disks 33, 34
and by means of two cover disks 32, 35, whereby the three
reflection chambers 26, 27, 28 are formed, each having a different
size or volume.
[0080] Each of the reflection chambers 26, 27 and 28 filters--on
account of its different size or volume and its differently
configured inlet opening 37--a certain frequency range, which has
been determined by means of frequency analysis of the noises in the
waste steam duct 24 and according to which the respective
reflection chamber 26, 27 or 28 has then been accordingly
dimensioned or adapted.
[0081] The reflection chambers 26, 27 and 28 represented are for
example in this case configured so as to damp frequencies or
frequency bands between 40 Hz and 500 Hz.
[0082] At the start--as seen in the flow direction 36--of a given
reflection chamber 26, 27 or 28, in a (starting) region 38 located
there, are created the inlet openings or slits 37, which are
distributed over the circumference of the inner tube 29 and are of
different configurations, and which allow the sound to enter from
the inner tube 29--through which the waste steam flows--into the
respective reflection chamber 26, 27 or 28.
[0083] The construction of the reflection silencer 2 is effected by
welding. The reflection chambers 26, 27 and 28 may (not shown) be
provided with cleaning openings.
[0084] The reflection chambers 26, 27 and 28 each have a drainage
opening 39 to a liquid discharge, in order that no waste steam
liquid or condensate, precipitated from the waste steam 25,
collects there, i.e. in the reflection chambers 26, 27 and 28, and
is caused to vibrate.
[0085] FIG. 3 shows a further configuration of a waste steam duct
24 equipped with the low-frequency silencer 2, as can be provided
in the steam turbine unit 1.
[0086] As shown in FIG. 3, at the beginning (as seen in the flow
direction 36) of the waste steam duct 24, there is arranged what is
termed a hotbox 40 which has multiple in-lines 43 (two in-lines 43
shown here), inter alia for bypass steam.
[0087] The low-frequency silencer 2 is arranged downstream (as seen
in the flow direction) of this hotbox 40, such that the waste steam
25 leaving or flowing out of the hotbox 40 flows through the
low-frequency silencer 2 and onward to the condenser 11.
[0088] As FIG. 3 also shows, the low-frequency silencer 2 has the
three reflection chambers 26, 27 and 28 which, however, have been
altered in terms of their volume by further additional separating
disks 41 and 42--in this case adapted to (other) low frequencies to
be damped.
[0089] Here, too, the reflection chambers 26, 27 and 28 are each
provided with a drainage opening 39.
[0090] In this case, the waste steam line 25 is outside a machine
casing (not shown) which incorporates the steam turbine 22.
[0091] Although the invention has been illustrated and described in
more detail by means of the preferred exemplary embodiment, the
invention is not limited by the disclosed example and other
variations may be derived herefrom by one skilled in the art
without departing from the scope of protection of the
invention.
* * * * *
References