U.S. patent application number 12/010583 was filed with the patent office on 2009-07-30 for kinetic steam condenser.
This patent application is currently assigned to Miracom Israel (2006) Ltd.. Invention is credited to Muhamed Osman.
Application Number | 20090188254 12/010583 |
Document ID | / |
Family ID | 40897839 |
Filed Date | 2009-07-30 |
United States Patent
Application |
20090188254 |
Kind Code |
A1 |
Osman; Muhamed |
July 30, 2009 |
Kinetic steam condenser
Abstract
Method and system for condensing steam at any temperature, the
steam being in contact with a large water surface, whereby the
relative temperatures of the steam and water are regulated so that
the steam is kept at under-saturation pressure and the water
temperature is kept at up to 100.degree. C.
Inventors: |
Osman; Muhamed; (Sakhnine,
IL) |
Correspondence
Address: |
Brux Software Solutions Ltd.
8 Gordon Street
Givatayim
53235
IL
|
Assignee: |
Miracom Israel (2006) Ltd.
Ramat Hasharon
IL
|
Family ID: |
40897839 |
Appl. No.: |
12/010583 |
Filed: |
January 28, 2008 |
Current U.S.
Class: |
60/670 ;
165/110 |
Current CPC
Class: |
Y02P 80/15 20151101;
F28B 3/02 20130101; F28B 9/00 20130101; Y02P 80/154 20151101 |
Class at
Publication: |
60/670 ;
165/110 |
International
Class: |
F28B 3/00 20060101
F28B003/00; F28B 9/00 20060101 F28B009/00 |
Claims
1. A method of condensing steam, the steam being in contact with a
large water surface, whereby the relative temperatures of the steam
and water are regulated so that the steam is kept at
under-saturation pressure and the water temperature is kept at up
to 100.degree. C.
2. The method of claim 1, wherein the temperature difference
between the steam and the water is kept below 10.degree. C.
3. The method of claim 2, wherein the temperature difference
between the steam and the water is kept below 5.degree. C.
4. The method of claim 1, wherein the steam is exhaust steam from a
power plant turbine and the condensate is reused as boiler feed
water.
5. The method of claim 4, wherein the temperature regulation
comprises heating the steam using hot gases discharged from the
power plant's chimney.
6. The method of claim 1, wherein the temperature regulation
comprises heating the steam using fuel burning.
7. The method of claim 1, wherein the temperature regulation
comprises recycling water through cooling means.
8. A steam condenser comprising: a steam inlet; a water inlet; a
plurality of water receiving surfaces; heating means for heating
the steam; control means for maintaining a predefined temperature
difference between the steam and the water and for maintaining the
water temperature below 100.degree. C.; and a condensate
outlet.
9. The steam condenser of claim 8, wherein the water receiving
surfaces comprise a plurality of trays, installed at various
heights.
10. The steam condenser of claim 9, wherein each tray comprises a
vertical bracket for holding water in the tray and a draining pipe
for draining excess water into a lower tray.
11. The steam condenser of claim 8, wherein the steam heating means
comprise pipes leading hot gases.
12. The steam condenser of claim 11, wherein the hot gases are
gases discharged from the power plant's chimney.
13. The steam condenser of claim 11, wherein the hot gases are
gases produced from burned fuel.
14. The steam condenser of claim 8, wherein the control means
comprise: means for measuring the steam temperature in the
condenser; and means for controlling the heating means
accordingly.
15. The steam condenser of claim 8, wherein the control means
comprise: means for measuring the water temperature in the
condenser; and means for recycling water through cooling means.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to steam condensing and more
specifically to a steam condensing apparatus and method that save
energy and increase efficiency.
BACKGROUND OF THE INVENTION
[0002] In power plants, on ships and in industrial plants, steam
condensers are used to condense the exhaust steam from a steam
turbine to obtain maximum efficiency and also to convert the
turbine exhaust steam into pure water (referred to as steam
condensate) so that it may be reused in the steam generator or
boiler as boiler feed water.
[0003] The most prevailing type of steam condenser are surface
condensers comprising a water cooled shell and a tube heat
exchanger installed on the exhaust steam from a steam turbine in
thermal power stations. These condensers are heat exchangers which
convert steam from its gaseous to its liquid state at a pressure
below atmospheric pressure. Where cooling water is in short supply,
an air-cooled condenser is often used.
[0004] Most of the heat liberated due to condensation of the
exhaust steam in surface condensers is carried away by the cooling
medium (water or air) used by the surface condenser. This heat is
known to be a significant contributor to global warming and is
wasted as a source of energy. Moreover, the energy required to
operate surface condensers is considerable.
[0005] There is need for an energy saving steam condenser, which
will reduce the adverse ecological effects of surface condensers
and increase the efficiency of the condensing process.
SUMMARY OF THE INVENTION
[0006] According to a first aspect of the present invention there
is provided a method of condensing steam at any temperature, the
steam being in contact with a large water surface, whereby the
relative temperatures of the steam and water are regulated so that
the steam is kept at under-saturation pressure and the water
temperature is kept at up to 100.degree. C.
[0007] According to a first embodiment, the temperature difference
between the steam and the water is kept below 10.degree. C.
[0008] According to a second embodiment, the temperature difference
between the steam and the water is kept below 5.degree. C.
[0009] According to a third embodiment, the steam is exhaust steam
from a power plant turbine and the condensate is reused as boiler
feed water.
[0010] According to a fourth embodiment, the temperature regulation
comprises heating the steam using hot gases discharged from the
power plant's chimney.
[0011] According to a fifth embodiment, the temperature regulation
comprises heating the steam using fuel burning.
[0012] According to a sixth embodiment, the temperature regulation
comprises recycling water through cooling means.
[0013] According to a second aspect of the present invention there
is provided a steam condenser comprising: a steam inlet; a water
inlet; a plurality of water receiving surfaces; heating means for
heating the steam; control means for maintaining a predefined
temperature difference between the steam and the water and for
maintaining the water temperature below 100.degree. C.; and a
condensate outlet.
[0014] According to a first embodiment, the water receiving
surfaces comprise a plurality of trays, installed at various
heights.
[0015] According to a second embodiment, the water receiving
surfaces comprise a plurality of trays installed at various
heights, each tray comprising a vertical bracket for holding water
in the tray and a draining pipe for draining excess water into a
lower tray.
[0016] According to a third embodiment, the steam heating means
comprise pipes leading hot gases.
[0017] According to a fourth embodiment, the hot gases are gases
discharged from the power plant's chimney.
[0018] According to a fifth embodiment, the hot gases are gases
produced from burned fuel.
[0019] According to a sixth embodiment, the control means comprise:
means for measuring the steam temperature in the condenser; and
means for controlling the heating means accordingly.
[0020] According to a seventh embodiment, the control means
comprise: means for measuring the water temperature in the
condenser; and means for recycling water through cooling means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] For better understanding of the invention and to show how
the same may be put into effect, reference will now be made, purely
by way of example, to the accompanying drawings.
[0022] It is stressed that the particulars shown are by way of
example and for purposes of illustrative discussion of the
preferred embodiments of the present invention only, and are
presented in the cause of providing what is believed to be the most
useful and readily understood description of the principles and
conceptual aspects of the invention. In this regard, no attempt is
made to show structural details of the invention in more detail
than is necessary for a fundamental understanding of the invention,
the description taken with the drawings making apparent to those
skilled in the art how the several forms of the invention may be
embodied in practice.
[0023] In the accompanying drawings:
[0024] FIG. 1 is a schematic diagram of the kinetic steam condenser
according to the present invention;
[0025] FIG. 2 is a schematic horizontal section along line 2-2
(FIG. 1) of the kinetic steam condenser according to the present
invention; and
[0026] FIG. 3 is a schematic three-dimensional view of the kinetic
steam condenser according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] Before explaining at least one embodiment of the invention
in detail, it is to be understood that the invention is not limited
in its application to the details of construction and the
arrangement of the components set forth in the following
description or illustrated in the drawings. The invention is
applicable to other embodiments or of being practiced or carried
out in various ways. Also, it is to be understood that the
phraseology and terminology employed herein is for the purpose of
description and should not be regarded as limiting.
[0028] The present invention provides a novel approach to steam
condensing, whereby the steam is condensed in high temperature, as
opposed to condensing by cooling.
[0029] The kinetic steam condenser of the present invention is
designed for condensing steam discharged from power stations
turbines at the end of the electricity production process, or for
any industrial plant or ship that use steam for operating their
systems.
[0030] The kinetic steam condenser of the present invention may be
operated in power stations using fuel oil, kerosene, coal, or any
other heating means.
[0031] The kinetic steam condenser of the present invention uses
hot steam discharged from the turbines, thus reducing significantly
the energy loss.
[0032] FIG. 1 is a schematic diagram of the kinetic steam
condenser, according to an embodiment of present invention. The
condenser (100) comprises an external housing (110) and an internal
housing (115), with an isolation layer (120) therebetween. External
housing (110) may be constructed of any suitable material such as
concrete or metal. Internal housing (115) may be constructed of any
suitable metal such as steel. Isolation layer (120) may comprise
any thermal insulating material known in the art and serves to
prevent heat loss and to maintain the temperature in the internal
housing.
[0033] According to one embodiment of the present invention, a
combustion chamber (125) at the bottom of condenser (100) serves as
heat source for the condenser's operation, where the heat may
result from burning fuel oil, kerosene, coal, or any other suitable
material in the combustion chamber (125).
[0034] According to another embodiment of the present invention,
hot gases discharged from power station's chimney may be channeled
through combustion chamber (125).
[0035] The hot gas from combustion chamber (125) flows through
pipes (130), preferably mounted at the center of condenser (100)
and spanning it from bottom to top. Pipes (130) may be constructed
of any metal, such as steel or copper. The number of pipes and
their diameters are adapted to the specific application, taking
into consideration the size of the condenser and the required duty
cycle.
[0036] The gas flows from the pipes (130) upper ends into chamber
(135), from which it is released via an exhaust pipe (140) into the
atmosphere.
[0037] A plurality of water trays (145) are attached to internal
housing (115) at different levels, surrounding the pipes (130).
Each tray (145) comprises a horizontal platform (150), a vertical
bracket (155) on the inner side of the platform (150) and at least
one draining pipe (160) drilled through the platform (150).
Draining pipes (160) serve to cascade excess water from each tray
to the tray below it.
[0038] A water temperature regulating system is attached to the
condenser, including a suction pipe 165, a radiator (170) for
reducing the water's temperature, a pump (175) for pumping water
from the radiator (170) and a pipe (180) through which the water is
returned to the condenser at the desired temperature. The water
temperature regulating system is operated periodically, when the
water temperature in the condenser needs to be decreased by a few
degrees, as will be explained in detail below.
[0039] A steam inlet (185) on the upper part of condenser (100)
allows steam from the power plant turbines to flow into the
condenser, where it flows freely and is heated by the hot pipes
(130).
[0040] A distilled water inlet (190) on the upper part of condenser
(100) serves for inserting distilled water into condenser (100)
before operating it. The water inserted through inlet (190)
cascades to the lower trays.
[0041] A condensate draining pipe (195) at the bottom of condenser
(100) drains the condensed steam which is flown back to the
turbine.
[0042] Thermometers (205, 210), installed inside the condenser
(100), serve for monitoring the temperatures of the steam and the
water, respectively, throughout the condensing process.
[0043] Air exhaust valve (215), at the upper side of condenser
(100), serves for releasing air, repelled by the incoming steam,
from the internal housing.
[0044] FIG. 2 is a schematic horizontal section of the kinetic
steam condenser (100) of FIG. 1, showing the internal housing (115)
and a tray (145) surrounding the central pipes (130) and having a
vertical bracket (155) and drilled draining pipes (160).
[0045] The operation of the kinetic steam condenser of the present
invention will now be explained.
[0046] The condensing process begins with distilled hot water being
inserted into the condenser (100) via water inlet (190). The water
is preferably inserted at a temperature below 90.degree. C. The
water cascades to the lower trays, so that each tray holds a
certain quantity of water.
[0047] The steam emerging from the turbines during the electricity
production process is at a temperature of less than 100.degree. C.
and therefore has pressure of less than 1 atm. and is on the verge
of saturation.
[0048] The steam is inserted into the condenser (100) through steam
inlet (185) and repels the air from within the condenser, through
air exhaust valve (215).
[0049] Next, the burning chamber (125) is operated, either by
burning fuel oil, kerosene, coal, or any other suitable material in
it, or by channeling hot gases discharged from power station's
chimney into it. The hot gas emanating from the burning chamber
(125) flows into pipes (130) and heats the steam in the condenser
by a few degrees.
[0050] Vapor-liquid equilibrium is a condition where a liquid and
its vapor (gas phase) are in equilibrium with each other, a
condition or state where the rate of evaporation (liquid changing
to vapor) equals the rate of condensation (vapor changing to
liquid) on a molecular level, such that there is no net (overall)
vapor-liquid interconversion.
[0051] The pressure of vapors in a vapor-liquid equilibrium is
called saturation pressure, and is constant at any given
temperature.
[0052] The temperature of the water in the trays (145) is lower by
a few degrees than that of the steam, causing the steam, which
aspires to a state of saturation pressure at any given temperature,
to start condensing into the water. The condensation releases heat
into the water and raises their temperature.
[0053] The condensation creates vacuum in the condenser, which
induces additional flow of steam into the condenser.
[0054] This process continues as long as there is a temperature
difference between the steam and the water in the condenser, so
that saturation pressure is never attained.
[0055] Thermometer (205) continuously monitors the steam
temperature and the burning rate at the burning chamber (125) is
adjusted accordingly, so as to prevent the steam temperature from
reaching a predefined temperature. In a preferred embodiment, the
steam temperature is kept below 100.degree. C.
[0056] Thermometer (210) continuously monitors the water
temperature. If the water temperature rises above a predefined
temperature, e.g. 90.degree. C., the water temperature regulating
system is operated, whereby water from the bottom of the condenser
are being pumped into radiator (170), where it is cooled by a few
degrees and flows back into the condenser, via pipe (180), at a
suitable temperature.
[0057] When the water/condensate level in each tray reaches the
opening of the drilled pipe (160), it flows into the tray below,
and so forth. The excess water accumulates at the bottom of the
condenser, where it flows out via draining pipe (195) into an
intermediate vessel (200), or directly into pipes leading to the
turbine.
[0058] The large number of trays (145) result in large contact
surfaces between the water and the steam, thus enabling the
condensation of large steam quantities. The larger the contact
surface, the higher is the condensation efficiency at any give
temperature.
[0059] The method of the present invention is applicable as long as
the water temperature is kept equal to or lower than 100.degree.
C.
EXAMPLE
[0060] A power station that produces 1400 MW/hour produces 1100
Tons of steam per hour, i.e. about 306 Kg of steam per second.
[0061] If we choose to have a water surface of 30 m.sup.2 for every
Kg of steam per second, we need a total water surface of 9180
m.sup.2 to condense 1100 Tons of steam per hour.
[0062] An exemplar condenser could comprise a 10 m diameter and 20
m height. 160 trays may be built, at height differences of about 12
cm, surrounding the heating pipes, each tray having a surface of 60
m.sup.2, so that the total surface of the trays, which is the total
water surface to be in contact with the steam, equals 9600
m.sup.2.
[0063] The kinetic steam condenser of the present invention is
operable in any temperature.
[0064] If the steam discharged from the power plant's turbines is
at 80.degree. C., the highest efficiency will be attained by
condensing it into water at 80.degree. C. Therefore, the steam will
be heated by 3-5.degree. C., and when the water in the trays
reaches 80.degree. C., the water temperature regulating system is
operated so as to keep the water at that temperature.
[0065] Conversely, in conventional power stations using cooling
condensers, the steam discharged from the turbines at approximately
80.degree. C. and 0.46 Atm. is cooled to 30.degree. C., a process
which uses huge quantities of energy. In the example above, the
power station that produces 1400 MW/hour and 1100 Tons of steam per
hour would require about 160,000 m.sup.3 of cooling water per
hour.
[0066] The amount of heat lost in cooling 1100 Tons of steam from
t.sub.2=80.degree. C. to t.sub.1=30.degree. C. is given by the
formula: Q=mc(t.sub.2-t.sub.1), where c=1 is the specific heat of
water.
Q=1,100,000.times.1(80-30)=55,000,000 Kcal
[0067] It is well known that the burning heat of 1 Kg petroleum is
10,000 Kcal, resulting in the cooling process requiring 5,500 Kg
petroleum/hour, which amounts to 132,000 Kg/24 hours or 48,180,000
Kg petroleum/year. This is on top of the huge amount of water
required for the cooling process and a significant part of the
condensing heat mK, where m is the amount of steam and K is is the
amount of condensing heat per 1 Kg of steam.
[0068] The majority of power stations work in less than 50%
efficiency, resulting in a net saving that is essentially a double
of the quantity calculated above, in the kinetic steam condenser of
the present invention.
[0069] The amount of energy required for the operation of the
condenser according to the present invention is approximately 550
Kg petroleum per hour, i.e. 5,500,000 Kcal/hour.
[0070] Unless otherwise defined, all technical and scientific terms
used herein have the same meanings as are commonly understood by
one of ordinary skill in the art to which this invention belongs.
Although methods similar or equivalent to those described herein
can be used in the practice or testing of the present invention,
suitable methods are described herein. In addition, the methods,
and examples are illustrative only and not intended to be
limiting.
[0071] It will be appreciated by persons skilled in the art that
the present invention is not limited to what has been particularly
shown and described hereinabove. Rather the scope of the present
invention is defined by the appended claims and includes both
combinations and sub-combinations of the various features described
hereinabove as well as variations and modifications thereof which
would occur to persons skilled in the art upon reading the
foregoing description.
* * * * *