U.S. patent application number 12/453918 was filed with the patent office on 2010-02-25 for arrangement for obtaining electrical energy from low temperature heat or waste heat.
Invention is credited to Ralf Baier, Michael Volk.
Application Number | 20100043436 12/453918 |
Document ID | / |
Family ID | 38961110 |
Filed Date | 2010-02-25 |
United States Patent
Application |
20100043436 |
Kind Code |
A1 |
Baier; Ralf ; et
al. |
February 25, 2010 |
Arrangement for obtaining electrical energy from low temperature
heat or waste heat
Abstract
The invention relates to an arrangement for obtaining electrical
energy from low temperature or waste heat. The heat energy is then
converted into electrical energy. Two heat exchangers (1, 2) are
configured as two pressure vessels and are connected to a
gas-pressure machine (4) built into a pressure vessel (3). Process
gas is introduced into the heat exchangers (1, 2) at a pressure of
20 to 200 MPa and thereafter, simultaneously, heat is introduced
via a flow channel (7) into the heat exchanger (1) and the cold is
introduced into the heat exchanger (2) via a flow channel (8).
Inventors: |
Baier; Ralf; (Oranienbaum,
DE) ; Volk; Michael; (Leipziq, DE) |
Correspondence
Address: |
WALTER OTTESEN
PO BOX 4026
GAITHERSBURG
MD
20885-4026
US
|
Family ID: |
38961110 |
Appl. No.: |
12/453918 |
Filed: |
May 27, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP2007/008353 |
Sep 26, 2007 |
|
|
|
12453918 |
|
|
|
|
Current U.S.
Class: |
60/645 ;
60/682 |
Current CPC
Class: |
F05D 2220/20 20130101;
F05D 2220/60 20130101; F02C 1/10 20130101; F02C 1/04 20130101 |
Class at
Publication: |
60/645 ;
60/682 |
International
Class: |
F01K 25/00 20060101
F01K025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2006 |
DE |
10 2006 046 874.0 |
Claims
1. An arrangement for obtaining electrical energy from low
temperature heat or exhaust heat, the arrangement comprising: first
and second flow channels; first and second heat exchangers disposed
in corresponding ones of said first and second channels; a pressure
vessel; and, a gas-pressure machine built into said pressure vessel
and being connected to said first and second heat exchangers.
2. The arrangement of claim 1, further comprising first and second
mediums disposed in corresponding ones of said first and second
flow channels so as to cause said first and second heat exchangers
to be externally surrounded by said first and second mediums,
respectively.
3. The arrangement of claim 2, wherein said first medium is warm
and said second medium is cold.
4. The arrangement of claim 2, wherein a process gas is disposed in
said first and second heat exchangers and in said gas-pressure
machine with said process gas being at a pressure lying in the
range of 20 MPa to 200 MPa.
5. The arrangement of claim 4, wherein said first medium is a warm
medium for imparting heat to said first heat exchanger and said
second medium is a cold medium for imparting cold to said second
heat exchanger and said second medium is colder than said first
medium; and, said pressure vessel is adapted to introduce said
process gas into said gas-pressure machine and into said first and
second heat exchangers at a pressure lying in the range of 20 to
200 MPa.
6. The arrangement of claim 5, wherein said pressure lies in the
range of 20 to 50 MPa.
7. The arrangement of claim 1, further comprising an electric
generator driven by said gas-pressure machine.
8. A method for operating an arrangement for obtaining electrical
energy from low temperature heat or exhaust heat, the arrangement
including: first and second flow channels; first and second heat
exchangers disposed in corresponding ones of said first and second
channels; a pressure vessel; a gas-pressure machine built into said
pressure vessel and being connected to said first and second heat
exchangers; first and second mediums disposed in corresponding ones
of said first and second flow channels so as to cause said first
and second heat exchangers to be externally surrounded by said
first and second mediums, respectively; and, said first medium
being a warm medium and said second medium being a cold medium; the
method comprising the steps of: introducing a process gas into said
first and second heat exchangers and into said gas-pressure machine
at a pressure in the range of 20 to 200 MPa; and, then introducing
heat from said first medium into said first heat exchanger via said
first channel and introducing cold from said second medium into
said second heat exchanger via said second channel.
9. The method of claim 8, wherein said pressure lies in a range of
20 to 50 MPa.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of
international patent application PCT/EP 2007/008353, filed Sep. 26,
2007, designating the United States and claiming priority from
German application 10 2006 046 874.0, filed Sep. 29, 2006, and the
entire content of both applications is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The invention relates to an arrangement for obtaining
electrical energy from low temperature heat or waste heat.
Thereafter, the thermal energy is converted into electrical
energy.
BACKGROUND OF THE INVENTION
[0003] According to a market study of the Fraunhofer Institut fur
Umwelt-, Sicherheits- und Energietechnik (UMSICHT) of December
2005, one can assume for Germany alone, a technically realizable
waste heat potential of 85 GWth which is broken down as
follows:
[0004] 6.7 GWth as industrial waste heat;
[0005] approximately 1 GWth from power plant facilities;
[0006] 63 GWth in the context of hydrothermal geothermics (depths
of 1500 to 3000 m); and,
[0007] 14 GWth in the context of further expansion of solar thermal
facilities.
[0008] Assuming a real electrical degree of efficiency in the range
of 6% to 10%, electrical power in the range of 5 to 8.5 GWel could
be obtained from waste heat sources with a use of suitable thermal
power processes. In this connection, reference can be made to the
internet address:
[0009] www.presseportal.de/story_rss.htx?nr=763828.
[0010] An enormous potential of low temperature heat remains unused
at the present time because of a lack of suitable energy
converters.
[0011] European patent publication 0,943,789 discloses an
arrangement for converting low temperature heat into electrical
energy. This arrangement includes at least two hermetically
sealable pressure vessels which are connected via a line. Means for
supplying heat to one vessel and cooling to another vessel are
provided which are in the form of heat exchangers arranged within
the interior spaces of respective vessels. The heat exchangers have
feed and outlet lines configured to be pressure tight toward the
outside.
[0012] The disadvantage of this arrangement is that the technical
realization is unfavorable and substantially disadvantageous for an
economic use because the possible power of such an arrangement is
greatly limited because of the arrangement of the heat exchangers
in the pressure vessels. In addition, work volume is lost to the
process because of the introduction of the heat exchangers in the
pressure vessels.
[0013] Gas-pressure machines available conventionally in the
marketplace require a very high volume flow. For this reason, the
above arrangements lead to component sizes which are not
economical.
SUMMARY OF THE INVENTION
[0014] It is an object of the invention to provide an arrangement
wherein the available heat energy is converted into electrical
energy at a relatively low temperature level at an economically
high degree of effectiveness.
[0015] According to a feature of the invention, process gas is
compressed at an absolute high pressure in two heat exchangers
configured as respective pressure vessels and the heat exchangers
are connected via lines to a gas-pressure machine which, in turn,
is built into a pressure vessel. The process gas can be, for
example, carbon dioxide, air, helium and/or other inert gases.
[0016] Thereafter, heat is supplied to the first heat exchanger via
a liquid or gaseous medium and, simultaneously, cold is supplied to
the second heat exchanger via respective flow channels. Because of
the occurring pressure difference, the medium flows from the first
heat exchanger via the gas-pressure machine into the second heat
exchanger thereby causing the gas-pressure machine to be
driven.
[0017] According to a feature of the invention, the pressure is
adjusted within the range of 20 to 200 MPa. An advantage of the
solution of the invention is that the heat exchangers can
simultaneously be used as pressure vessels. In this way, the
arrangement of the invention can be configured to be compact and is
also suitable for small applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention will now be described with reference to the
drawings wherein:
[0019] FIG. 1 is a schematic showing the arrangement of the
invention for obtaining electric energy from low temperature heat
or waste heat; and,
[0020] FIG. 2 is a schematic showing the process gas flow circuit
and the flows of the first and second mediums through the first and
second heat exchangers.
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
[0021] In FIG. 1, heat exchangers 1 and 2 are connected to each
other on the one hand and to a pressure vessel 3 on the other
hand.
[0022] A gas-pressure machine 4 is arranged in the pressure vessel
3 in such a manner that this gas-pressure machine 4 is connected
via the pressure vessel 3, on the one hand, to heat exchanger 1
and, on the other hand, to heat exchanger 2. In this way, heat
exchangers (1, 2) and the gas-pressure machine 4, which is arranged
in the pressure vessel 3, define a process-gas loop filled with a
process gas such as carbon dioxide, air, helium and/or other inert
gases. Reference numeral 10 identifies an opening for pressure
equalization between pressure vessel 3 and gas-pressure machine
4.
[0023] The gas-pressure machine drives a generator 12 for
generating electric power.
[0024] Furthermore, the heat exchanger 1 is surrounded by a medium
5 and the heat exchanger 2 by a medium 6. The medium 5 is conducted
in a flow channel 7 and the medium 6 in a flow channel 8 and the
heat exchanger 1 is arranged in the flow channel 7 and the heat
exchanger 2 in the flow channel 8. The medium 5 is warm and lies,
for example, in a temperature range of +20.degree. C. to
+400.degree. C. and the medium 6 is cold and lies, for example, in
a temperature range of -50.degree. C. to +50.degree. C. The process
gas in the gas-pressure machine 4 is at a pressure lying in the
range between 20 and 200 MPa, preferably in a range lying between
20 to 50 MPa.
[0025] A warm medium 5 is disposed in the flow channel 7 and a cold
medium 6 is disposed in the flow channel 8. The process gas
disposed in the heat exchanger 1 is heated by the heat exchanger 1
and the process gas has a pressure of 50 MPa.
[0026] As a consequence of the temperature difference of the
process gas in the heat exchanger 1 and heat exchanger 2, the
heated process gas flows through the gas-pressure machine 4 into
the heat exchanger 2 because of a pressure difference which results
from the temperature difference. In the process, the process gas
performs work in the gas-pressure machine 4. The process gas is
cooled down in the heat exchanger 2 by the cold medium 6 and flows
as a cold process gas out of heat exchanger 2 directly into heat
exchanger 1. In the heat exchanger 1, the process gas is again
heated by the warm medium 5 and the cycle begins anew.
[0027] The warm medium 5 as well as the cold medium 6 can be at
rest or can be flowing mediums. An at-rest medium can, for example,
be a lake and a flowing medium can, for example, be a river or a
ground water flow. It is, however, also conceivable that any other
suitable medium can be used as the warm medium 5 and/or cold medium
6.
[0028] It is understood that the foregoing description is that of
the preferred embodiments of the invention and that various changes
and modifications may be made thereto without departing from the
spirit and scope of the invention as defined in the appended
claims.
* * * * *
References