U.S. patent application number 12/293696 was filed with the patent office on 2010-09-02 for condenser which is exposed to air.
This patent application is currently assigned to GEA Energietechnik GmbH. Invention is credited to Heinrich Schulze.
Application Number | 20100218537 12/293696 |
Document ID | / |
Family ID | 38279081 |
Filed Date | 2010-09-02 |
United States Patent
Application |
20100218537 |
Kind Code |
A1 |
Schulze; Heinrich |
September 2, 2010 |
CONDENSER WHICH IS EXPOSED TO AIR
Abstract
The invention relates to a condenser (1) which is exposed to
air, having a ventilator (2) which conveys cooling air, is arranged
in particular below condensation elements (4, 5) arranged in an
A-shape, and presses intake cooling air into the triangular
interior space (6) which is delimited by the ventilator (2) and the
condensation elements (4, 5). Also provided are means for adiabatic
cooling of the cooling air, wherein the means for adiabatic cooling
are contact bodies (7) which can be placed in contact with water to
be evaporated and which are arranged in the region of the cooling
air flow (3).
Inventors: |
Schulze; Heinrich; (
Sprockhovel, DE) |
Correspondence
Address: |
HENRY M FEIEREISEN, LLC;HENRY M FEIEREISEN
708 THIRD AVENUE, SUITE 1501
NEW YORK
NY
10017
US
|
Assignee: |
GEA Energietechnik GmbH
44809 Bochum
DE
|
Family ID: |
38279081 |
Appl. No.: |
12/293696 |
Filed: |
March 13, 2007 |
PCT Filed: |
March 13, 2007 |
PCT NO: |
PCT/DE2007/000449 |
371 Date: |
September 19, 2008 |
Current U.S.
Class: |
62/314 |
Current CPC
Class: |
F28B 1/06 20130101; F28D
5/00 20130101; F28B 9/00 20130101; F28F 25/04 20130101 |
Class at
Publication: |
62/314 |
International
Class: |
F28D 5/00 20060101
F28D005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 20, 2006 |
DE |
10 2006 013 011.1 |
Claims
1-18. (canceled)
19. An air-operated condenser, comprising: a condensation element,
a ventilator for generating a cooling air flow in a region of the
condensation element, and an evaporative element for adiabatic
cooling of the cooling air flow, said evaporative element located
in a region of the cooling air flow and receiving a quantity of
water to be evaporated.
20. The condenser of claim 19, wherein the condensation element is
configured to condense water vapor.
21. The condenser of claim 19, wherein the ventilator is installed
upstream of the condensation element in a flow direction of the
cooling air flow, the evaporative element being arranged in an
intake region of the ventilator.
22. The condenser of claims 19, wherein the ventilator is installed
upstream of the condensation element in a flow direction of the
cooling air flow, the evaporative element being arranged in an
outlet region of the ventilator.
23. The condenser of claim 19, wherein the ventilator is installed
downstream of the condensation element in a flow direction of the
cooling air flow.
24. The condenser of claim 22, wherein the evaporative element is
arranged proximate to the condensation element and covers at least
part of a surface of the condensation element exposed to the
cooling air flow.
25. The condenser of claim 24, wherein an area of the surface of
the condensation element covered by the evaporative element is
adjustable by repositioning the evaporative element.
26. The condenser of claim 22, wherein the evaporative element is
rotatable in the cooling air flow.
27. The condenser of claim 24, wherein evaporative element is
affixed directly to the condensation element.
28. The condenser of claim 27, wherein the condensation element
comprises tubes with end faces and fins, wherein the evaporative
element is attached to the end faces of the tubes.
29. The condenser of claim 19, wherein the evaporative element
comprises a non-woven fabric.
30. The condenser of claim. 19, wherein the evaporative element
comprises a porous synthetic material.
31. The condenser of claim 19, further comprising a metering system
for controlling the quantity of water received by the evaporative
element.
32. The condenser of claim 31, wherein the quantity of water
received by the evaporative element does not exceed a quantity
amount of water evaporated from the evaporative element.
33. The condenser of claim 31, wherein the metering system
comprises a metering line disposed proximate to the evaporative
element and having apertures for supplying the quantity of water to
the evaporative element.
34. The condenser of claim 31, wherein the metering system
comprises a metering line embedded in the evaporative element and
having apertures for supplying the quantity of water to the
evaporative element.
35. The condenser of claim 33, wherein the quantity of water to be
evaporated is pre-heated in the metering line by heat transfer from
the condensation element to the metering line.
36. The condenser of claim 34, wherein the quantity of water to be
evaporated is pre-heated in the metering line by heat transfer from
the condensation element to the metering line.
37. The condenser of claim 28, wherein the metering line extends
between an end face of the condensation element and the evaporative
element attached to the end face.
Description
[0001] The invention relates to a condenser which is exposed to air
having the features as set out in the generic clause of patent
claim 1.
[0002] It is known that by pre-moistening the cooling air, i.e.
so-called adiabatic cooling, the cooling performance of air-cooled
condensers can be increased substantially, in particular during
operation in summer. Particularly in the case of relatively large
plants in the power plant sector it was not possible to date to
find a practical and reliable solution of this problem as H B
Goldschagg describes in "Lessons learned from the world's largest
forced draft direct air cooled condenser", EPRI Conference,
Washington D.C., 01-Mar. 3, 1993. On the other hand, there is an
increasing demand for functional and efficient pre-moistening means
by operators of such plants.
[0003] The fundamental drawback of known adiabatic cooling systems
is soaking of the cooling elements, support structures and other
structural plant components arranged below the cooling elements.
Soaking of the cooling elements, in the long term, results in an
undesirable deposit of insoluble substances, while electric
components such as e.g. transformers must be protected entirely
against the entry of moisture in order to avoid short circuits.
Exact dosing of the water as well as its distribution can only be
calculated with difficulty, since the distribution of the water
droplets depends, inter alia, on the wind direction and the
temperature distribution. Uneven distribution results inevitably in
localised soaking and, consequently, also in drop formation, i.e.
the water drips down along the condensers and the support
structure. This may result in undesirable corrosion, even if
demineralised water is used.
[0004] Proceeding on this basis, it is the object of the invention
to so improve a condenser exposed to air that the condensing
elements are not soaked by the means provided for adiabatic cooling
of the cooling air, the said means for adiabatic cooling also being
able to be retrofitted with little effort.
[0005] This object is attained by a condenser exposed to air having
the features of patent claim 1.
[0006] The essence of the invention is that the means for adiabatic
cooling are contact bodies to which water to be evaporated is to be
fed and which are arranged in the region of the cooling air flow,
that is to say on the flow-impacted side of the condensing
elements. The contact bodies possess a large surface area, on which
water fed into the contact bodies may evaporate. The water is at no
point in time kept freely within the cooling air flow, as is the
case when spraying with nozzles. In contrast to atomising or
spraying, virtually no excess water is required since the water
taken up by the contact bodies is transferred to the cooling air
flow by mass transfer, i.e. evaporation, alone. This further
ensures that damage caused by corrosion due to undesirable moisture
on components in the vicinity, such as e.g. the ventilator, is
avoided.
[0007] A substantial increase in performance at moderately
increased investment costs is expected from the condenser exposed
to air, designed according to the invention. New plants to be set
up may be built smaller in size, even with a predetermined output,
if adiabatic cooling, using contact bodies, is provided. As a
result, the production costs of new plants can most probably be
reduced. It is a further advantage that output deficits, e.g.
necessitated by hot air recirculation, may be reduced and that, on
the other hand, the output of a power plant may be increased at the
same time by several 10 kPA by reducing the turbine waste steam
pressure.
[0008] Advantageous embodiments of the inventive concept form the
subject of the subsidiary claims.
[0009] The condenser exposed to air according to the invention is
preferably provided for the condensation of water vapour. In
particular, condensers are provided for condensing the waste steam
flow from a turbine of a power plant. In principle, it is, however,
also conceivable to provide the condensers exposed to air for
condensing other substances, such as, for example, for condensing
propane. The inventive concept is not limited to condensing water
vapour. The condenser exposed to air, according to the invention,
is likewise also not limited to a specific type of condenser. In
principle, the contact bodies to which water to be evaporated is to
be fed, may be used in combination with condensation elements
arranged in an A-shape, V-shape, vertically or horizontally. The
use of these contact bodies in conjunction with condensation
elements arranged in an A-shape or in a roof-like fashion is
considered to be particularly advantageous.
[0010] With regard to the arrangement of the contact bodies in the
region of the cooling air flow, various modifications are possible.
In a first embodiment, the contact body may be arranged in the
intake region of the ventilator upstream of the condensation
elements, i.e. it is present in the flow direction upstream of the
ventilator. The air pre-moistened in this manner flows through the
ventilator, subsequently entering e.g. into the triangular interior
between condensation elements arranged in an A-shape. Contact
bodies may, for example, be mounted in conjunction with a
protective screen fitted upstream of the ventilators.
[0011] In a second modification, contact bodies may also be
arranged in the exit region of the cooling air flow of the
ventilator, i.e. in the direction of the cooling air flow
downstream of the ventilator.
[0012] In principle, it is also conceivable to use the means for
adiabatic cooling at a location where cooling air is not pressed
through the condensation elements, but is sucked in. In this case,
the ventilator is fitted downstream of the condensation element,
which has no effect on the efficiency of adiabatic cooling.
[0013] A further modification provides that contact bodies are
arranged immediately upstream of the condensation elements,
covering at least a portion of the flow-impacted surface of the
condensation elements. The contact bodies may in this case cover
the entire flow-impacted surface of the condensation elements or
even only part of the surface. It is conceivable that e.g. only
some of the condensation elements are provided with contact bodies
while others are not. Partial covering of the condensation elements
may e.g. take place in the upper, central or lower third thereof.
The respective degree of covering and the exact positioning of the
contact bodies must depend on the local circumstances. No rigid
rule can be mentioned here.
[0014] It is considered to be particularly advantageous if the
degree of covering the flow-impacted surface can be adjusted by
repositioning the contact bodies. In the event that the contact
bodies are deactivated, i.e. that no pre-moistening of the cooling
air is desired, the said contact bodies may e.g. be swivelled and
lifted from the cooling air flow in a certain manner, so that a
larger flow-impacted surface of the condensation elements becomes
available for pure dry cooling. Swivelling has furthermore the
advantage that no additional loss of pressure, caused by the
contact bodies, arises.
[0015] The axis about which the contact bodies are swivelled
depends on the spatial circumstances. For example, in the case of
condensation elements arranged in an A-shape, the swivelling axis
may extend in the ridge region, i.e. substantially horizontally,
but at least parallel to the planes spanned by the condensation
elements. It is also conceivable for the swivelling axis not to
extend horizontally, but parallel to the planes spanned by the
condensation elements, i.e. according to the inclination of the
condensation elements in the case of condensation elements arranged
in an A-shape. If spatial circumstances permit, the contact bodies
may also be arranged in a manner to be translationally
displaceable.
[0016] It is considered to be particularly advantageous if contact
bodies are fixed directly to the condensation elements on their
sides facing the ventilator. The contact bodies may e.g. be fixed
to the end faces of tubes of the condensation elements, the said
tubes being provided with fins on the transverse sides. Fixing of
contact bodies directly to the condensation elements results only
in a negligible increase of the flow resistance, so that no
pressure losses whatsoever occur. The contact bodies are
nevertheless situated entirely within the cooling air flow. As with
the arrangement of contact bodies in the direction of flow upstream
of the condensation elements, it is possible to provide contact
bodies fixed directly to the condensation elements in some regions
only. For example, each second tube of the condensation elements
might be provided with contact bodies.
[0017] The contact bodies are preferably represented by a non-woven
fabric, a woven fabric or porous plastics. The essential
properties, which appropriate contact bodies exhibit, are a high
storage capacity for water and a large surface area to permit rapid
evaporation of the water. In addition, the material
employed--depending on the disposition within the cooling air
flow--should be adequately air permeable in order to limit pressure
losses. Self-supporting materials are considered to be particularly
advantageous, while composite multi-layered materials, wherein one
layer of the contact body fulfils the support function while at
least one other layer is designed especially for water absorption
and high evaporation, may be employed as well. Commonly available
and reasonably priced materials are geo-textiles or non-woven
fabrics offering the desired absorbency and good water evaporation
ability. The said materials are highly ageing resistant and are
furthermore adequately mechanically resistant. The contact bodies
can preferably be cleaned after a predetermined period of use and
can subsequently be re-used. If possible, the contact body should,
therefore, not decompose under the influence of air and water. By
appropriately choosing the material, both high mechanical
load-bearing capacity and, at the same time, a correspondingly
desired water absorption capability may be attained. Both are
prerequisites for the use within the cooling air flow in air-cooled
condensers. The contact bodies preferably take the form of plane
panels. It is, of course, possible that single-layered or
multi-layered contact bodies deviate from plane panels with regard
to their geometry, i.e. that they are, for example, corrugated or
that their profile is adapted to the flow conditions of the
air-cooled condenser or that they are provided to specifically
influence the flow conditions by their positioning and contouring.
This means that the contact bodies, depending on their positioning
and contouring, may also possess a certain conducting or deflecting
function in relation to the cooling air flow.
[0018] It is important for the condenser according to the invention
that the amount of the water to be introduced into the contact
bodies is so selected that no substantial excess occurs which would
result in soaking the plant. For this reason, a metering system
controlling the volume of the water to be introduced into the
contact bodies is provided, which systematically feeds the exact
amount of water to the contact body which needs to be fed under the
given climatic conditions and operating states of the plant in
order to ensure maximum evaporation in the region of the contact
bodies. This system may in the present case be a control circuit or
even a regulating circuit equipped with appropriate measuring
devices. The measuring devices detect whether water is present at
determined measuring points outside the contact bodies from which
may be concluded that too much water for evaporation was fed to the
contact bodies.
[0019] In order to improve the water distribution inside the
contact bodies, provision is made for a metering line to extend
adjacent to a contact body, having a plurality of apertures,
through which the water to evaporate can be fed into the contact
body. In the present case, this may be a rigid or flexible line,
extending in the peripheral region of the contact bodies. By
utilising gravity, such a metering line can introduce water into a
contact body, for example from above. The water flows down inside
the contact body, wets its surface and evaporates within the
cooling air flow. The amount of water is metered in such a way that
on its way through the contact body it only just reaches the lower
end, partially already evaporating on its way there. It is also
conceivable for the metering lines to be arranged on the surface of
the contact body facing the cooling air flow or facing away from
it. As a result, the paths to be covered by the water inside a
panel-shaped contact body are shorter, ensuring a more uniform
distribution of the cooling water, which also simplifies metering.
In this context, it is considered to be particularly advantageous
if the metering line is embedded in the contact body. This may be
realised, for example, by a metering line installed in a meandering
fashion, positioned, for example, between two contact bodies in the
form of a non-woven fabric. Both contact bodies are wetted equally
with water by the metering line. This minimises the risk of water
emerging from the non-woven fabric in an uncontrolled manner.
[0020] It is furthermore considered to be advantageous if the water
to be evaporated is pre-heated in the metering lines, i.e. by heat
transfer from the condensation elements to the metering lines. For
this purpose, the metering lines may extend between the end faces
of the condensation elements and the contact bodies fixed to the
end faces. The water so pre-heated withdraws to a small extent heat
from the condensation elements, thus evaporating more rapidly in
the region of the contact bodies. This increases the efficiency of
a condenser which is exposed to air in this manner.
[0021] The invention is elucidated in what follows by way of the
embodiments shown in the schematic drawings. There is shown in:
[0022] FIG. 1 a schematic view of a condenser exposed to air, in an
A-shape, or, respectively in a roof-like design with additional
contact bodies for the evaporation of water;
[0023] FIGS. 2 to 4 further embodiments of a dry cooler in a
roof-like design with different arrangements of the contact
bodies;
[0024] FIG. 5 a perspective view of a condensation element with
contact bodies fixed thereto;
[0025] FIG. 6 an embodiment of a contact body including a
meandering metering line in plan view;
[0026] FIG. 7 the contact body according to FIG. 1 in longitudinal
section and
[0027] FIG. 8 a further embodiment of a contact body including a
metering line.
[0028] FIG. 1 shows an air-exposed condenser 1 of A-type
construction as known in the state of the art in its basic form. An
air-exposed condenser 1 of this type is mounted on a steel frame,
not shown in detail, so that cold cooling air in a cooling air flow
3 may be sucked in from below by a ventilator 2 and may be pressed
into the triangular interior 6 delimited by the condensation
elements 4, 5. The cooling air flows through the condensation
elements taking the form of nests of finned tubes 4, 5 and is
heated in the course thereof. At the same time, the water vapour
passing through the condensation elements 4, 5 is cooled and
condensed. In this first embodiment a contact body 7 is arranged in
the intake region 8 of the ventilator 2. The cooling air is
pre-moistened by the contact body 7. The cooling air flows through
the contact body 7, to which water is fed in a manner not shown in
detail. The contact body 7 is preferably a non-woven fabric or a
porous structure made of plastics. The water which has been
introduced, is transferred to the cooling air by mass transfer so
that the cooling performance of the condenser 1 exposed to air can
be increased substantially, in particular during operation in
summer.
[0029] In the embodiment according to FIG. 2 a contact body 7a is
situated in the outlet region 9 of the cooling air flow 3 exiting
from the ventilator 2, i.e. it is arranged in the interior 6
between the condensation elements 4, 5.
[0030] A third embodiment is shown in FIG. 3. There, a contact body
7b is provided which may be swivelled between two positions A, B.
In this manner, the degree of covering the flow-impacted surface 10
of the condensation elements 4, 5 can be altered. This allows
modifying the pressure loss which inevitably occurs when passing
through the contact body 7b. In particular, if the connection of
the contact body 7b is not required, the latter may be moved from
position A to position B.
[0031] FIG. 4 shows an embodiment with a contact body 7c, which can
be swivelled about a swivelling axis S. As a result, the contact
body 7c may be moved into the position illustrated by the broken
line. In contrast to the embodiment according to FIG. 3, one can
possibly expect a lesser impact on the flow performance in the
embodiment shown in FIG. 4. The swivelling axis S in this
embodiment extends parallel to the condensation elements 5. It is,
of course, also conceivable to arrange the contact body 7c on the
other condensation element 4, in which case the swivelling axis S
would then, of course, extend parallel to this condensation element
4.
[0032] The embodiment according to FIG. 5 is considered to be
particularly advantageous. FIG. 5 shows a perspective view of the
condensation element 4 when viewed in a direction out of the
interior 6. The condensation element 4 comprises a number of tubes
11, arranged side by side, through which passes water vapour. The
tubes 11 have an elongated, almost rectangular cross-section, fins
13 being situated between the mutually facing transverse sides 12
of the tubes 11 and the cooling air flow 3 flowing around the said
fins 13. The particularity of the condensation element 4 shown is
that contact bodies 7d are fixed to the respective end faces 14
without fins, which contact bodies, by way of example, are
indicated by the hatched lines in the drawing. Such contact bodies
7d do not project laterally into the finned intermediate space,
i.e. they also do not reduce the flow cross-section between the
tubes 11. In spite thereof an intensive exchange takes place with
the cooling air flowing past, which is moistened in the course
thereof.
[0033] In all aforegoing figures the illustration of one or more
metering lines for feeding the contact bodies with water has been
omitted. FIGS. 6 to 8 show planar contact bodies in various views,
the arrangement of the metering line 15 being particularly
important. The metering line 15 shown in FIG. 6 extends on the
surface of the contact body 7e shown. The metering line 15 has a
multitude of apertures, not shown, via which the water to be
evaporated is introduced into the contact body 7e. The meandering
pattern ensures uniform water admission into the contact body
7e.
[0034] FIG. 7 shows the contact body 7e of FIG. 5 in longitudinal
section. It can be seen that the metering line 15 in this
embodiment borders directly onto the schematically indicated
condensation element 4, so that the heat prevailing in the
condensation element 4 is transferred to the metering line 15 and,
therefore, to the water to be evaporated.
[0035] In contrast thereto, the metering line 15 in the embodiment
according to FIG. 8 is positioned approximately in the centre of
the contact, body shown. This modification, in turn, has the
advantage that the water to be evaporated must inevitably first
pass through the contact body 7e shown, before attaining the
surface of the contact body 7e. The latter is wetted on the way to
the outer surface of the contact body 7e.
[0036] It is also conceivable to embed the metering line between
two contact bodies, the water to be evaporated being released on
both sides of the metering lines.
LIST OF REFERENCE NUMERALS
[0037] 1--Condenser [0038] 2--Ventilator [0039] 3--Cooling air
[0040] 4--Condensation element [0041] 5--Condensation element
[0042] 6--Interior [0043] 7--Contact body [0044] 7a--Contact body
[0045] 7b--Contact body [0046] 7c--Contact body [0047] 7d--Contact
body [0048] 7e--Contact body [0049] 8--Intake region [0050]
9--Outlet region [0051] 10--Flow-impacted surface [0052] 11--Tube
[0053] 12--Transverse side [0054] 13--Fin [0055] 14--End face of 11
[0056] 15--Metering line [0057] A--Position of 7b [0058]
B--Position of 7b
* * * * *