U.S. patent application number 12/799688 was filed with the patent office on 2011-11-03 for system and a method of energy recovery from low temperature sources of heat.
Invention is credited to Ari Nir.
Application Number | 20110265501 12/799688 |
Document ID | / |
Family ID | 44857172 |
Filed Date | 2011-11-03 |
United States Patent
Application |
20110265501 |
Kind Code |
A1 |
Nir; Ari |
November 3, 2011 |
System and a method of energy recovery from low temperature sources
of heat
Abstract
A system of energy recovery from low temperature sources of
heat, comprising components of Organic Renkine Cycle (ORC)
including a turbine from which an ORC vapor is withdrawn, a
condenser in which the ORC vapor withdrawn from the turbine
condenses into an ORC condensate, a pump which circulates the ORC
working medium, a heat exchanger which is supplied with a heat
carrier from a lower temperature heat source and in which the ORC
working liquid, and an ARC Condenser in which the ORC working
liquid is heated or evaporates to produce ORC working vapor which
is supplied to the turbine; components of an absorption
refrigeration cycle (ARC) including an absorption refrigeration
machine which receives heat and vaporizes a liquid refrigerant of
the ARC to produce an ARC refrigerant vapor which is supplied to
the ARC condenser to heat the ORC working liquid; and an additional
component increasing a temperature difference between the ORC
condensate and the heat carrier from the low temperature heat
source.
Inventors: |
Nir; Ari; (Doral,
FL) |
Family ID: |
44857172 |
Appl. No.: |
12/799688 |
Filed: |
April 29, 2010 |
Current U.S.
Class: |
62/113 ;
62/238.4 |
Current CPC
Class: |
F01K 25/065 20130101;
F01K 25/08 20130101 |
Class at
Publication: |
62/113 ;
62/238.4 |
International
Class: |
F25B 27/00 20060101
F25B027/00 |
Claims
1. A system of energy recovery from low temperature sources of
heat, including components of Organic Renkine Cycle (ORC)
comprising: ORC working medium, a turbine from which a vapor of an
ORC working medium is withdrawn, a condenser in which the ORC vapor
withdrawn from the turbine condenses into a condensate, which is
also an ORC working liquid, a pump which circulates the working
liquid, a heat recovery heat exchanger which is supplied with a
heat carrier from a low temperature heat source and in which the
ORC working liquid is heated, an a ARC condenser in which the ORC
working liquid is heated or evaporates to produce the ORC working
vapor which is supplied to the turbine, an additional optional ORC
evaporator to generate an ORC working vapor which is supplied with
a heat carrier from a high temperature heat source, and including
components of Absorption Refrigeration Cycle (ARC) comprising ARC
refrigerant, an absorption refrigeration machine which receives
heat and vaporizes an ARC refrigerant to produce an ARC refrigerant
an ARC condenser to heat the ORC working liquid, an expansion valve
provides an adiabatic expansion of the ARC refrigerant liquid
passing from an ARC refrigerant condenser to an ARC refrigerant
evaporator and an additional component, which may be a heat
exchanager, increasing a temperature difference between the ORC
condensate and the heat carrier from the low temperature heat
source.
2. A system of energy recovery as defined in claim 1; further
comprising an additional heat source which supplies heat to the
absorpotion refrigeration machine to vaporize ARC refrigerant.
3. A system of energy recovery as defined in claim 1; further
comprising a pump circulating an ORC working medium
4. A system of energy recovery as defined in claim 1; further
comprising an ORC regenerator connecting said additional component
with said ARC condenser, in which the ORC working liquid is further
heated by the condensing ARC vapor.
5. A system of energy recovery as defined in claim 1; further
comprising an ORC evaporator which is connected with said ARC
condenser and said turbine to evaporate the ORC working liquid
coming from said ARC condenser.
6. A system of energy recovery as defined in claim 1, wherein said
turbine is connected with said absorption refrigeration machine so
that the working vapor of the ORC working medium withdrawn from
said turbine heatS and vaporizes the the ARC refrigerant in the
absorption refrigeration machine.
7. A method of energy recovery from low temperarture sources of
heat, comprising the step of: in an Organic Renkine Cycle (ORC)
withdrawing from a turbine an ORC working vapor into a condenser
condensing the ORC working vapor withdrawn from the turbine into a
condensate which is ORC working liquid, pumping the ORC working
medium, in a heat recovery heat exchanger supplying a heat carrier
from a lower temperature heat source and heating the ORC working
liquid, and in an ARC Condenser heating the ORC working liquid or
evaporating it to produce ORC working vapor which is supplied to
the turbine; in an absorption refrigeration cycle (ARC) in an
absorption refrigeration machine receiving heat and vaporizing an
ARC refrigerant to produce an ARC refrigerant vapor which is
supplied to the ARC condenser heating the ORC working liquid and
increasing a temperature difference between the ORC condensate and
the heat carrier from the low temperature heat source in an
additional component.
8. A method of energy recovery as defined in claim 1; further
comprising supplying heat from an additional heat source to the
absorption refrigeration machine to vaporize the ARC
refrigerant.
9. A method of energy recovery as defined in claim 1; further
comprising in an ORC regenerator connecting said additional
component with said ARC condenser which is further heating the ORC
working liquid by the ARC condesing vapor.
10. A method of energy recovery as defined in claim 1; further
comprising in an evaporator which is connected with said ARC
condenser and said turbine, evaporating the ORC working liquid
coming from said ARC condenser.
11. A method of energy recovery as defined in claim 1, further
comprising connecting said turbine with said absorption
refrigeration machine so that the working vapor of the ORC working
medium withdrawn from said turbine heats and vaporizes the ARC
refrigerant in the absorption refrigeration machine.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a system and method of
energy recovery from low temperature sources of heat.
[0002] Thermodynamic Cycles transferring low temperature heat to
electricity are known in the industry.
[0003] In the Kalina Thermodynamic cycle, heat is added to a
multi-component mixture that typically contains ammonia and water.
This causes the most volatile component to boil off at the lowest
temperature. The boiling point changes with the composition,
allowing the boiling process to occur at a range of temperatures.
This is unlike the Renkine cycle where the boiling temperature is
uniquely determined by the pressure. The vapor produced in the
boiling process then passes through a turbine which drives the
generator, and then to an absorber. The low volatile liquids (which
are not boiled in the boiler) are returned to the absorber where
they absorb the vapor exhausted from the turbine. The resulting
solution is then pumped to a higher pressure and returned to the
boiler. The Kalina process is described in U.S. Pat. Nos. 4,346,561
and 4,489,563.
[0004] The Thermodynamic Renkine cycle is commonly known as the
steam cycle. In the Renkine cycle water is boiled at high
temperature and pressure. The resulting steam is then expanded to a
turbine or other device, extracting work to drive an electric
generator. The heat is then removed from the steam in a condenser,
converting it to water which is then pumped to a higher pressure
and returned to the boiler.
[0005] The Organic Renkine Cycle is known as the Renkine
Thermodynamic cycle having a working fluid boiled at low
temperature and pressure, for example, hydrofluorocarbons,
chlorofluorocarbons, ammonia or others. Due to low boiling
temperature, ORC is commonly used to recover energy from low
temperature heat sources. The amount and the efficiency of ORC
systems depend on the temperature difference between a heat source
and a working fluid of the cycle. Today the economically justified
minimal temperature difference is about 150 deg. F. Due To very
high cost of systems energy of many low temperature sources is
wasted.
[0006] Absorption Refrigeration Cycle is known in the industry for
using waste heat to generate heat and cold. Many concepts of
coupling the absorption cycle ARC to the Organic Renkine Cycle
(ORC) devein by a low temperature heat source have been
evaluated.
[0007] One option of the combined ARC-ORC involves the use of an
ARC to increase the temperature of the ORC working liquid fed to
the ORC evaporator using external high temperature heat sources. A
second alternative proposes the introduction of a vapor absorption
chiller to lower the temperature of the working vapor fed to the
ORC condenser, similarly to an ORC regenerator, in order to
decrease heat losses by an ORC condenser to the ambient. In both
cases the purpose is to increase the thermodynamic efficiency of
the (ORC).
[0008] It is believe that the known systems and methods can be
further improved.
SUMMARY OF THE INVENTION
[0009] Accordingly, it is an object of the present invention to
provide a system and a method of energy recovery from low
temperature sources of heat, which is a further improvement of the
existing systems and methods.
[0010] In keeping with these objects and with others which have
become apparent hereinafter, one feature of the present resides,
briefly stated, in a system of energy recovery from low temperature
sources of heat, comprising: [0011] components of Organic Renkine
Cycle (ORC) including A low temperature source of heat, one or more
high temperature sources of heat, a low temperature ORC boiling
medium, for instance ammonia, hydrocarbons or others a turbine from
which an ORC vapor is withdrawn, a condenser in which the ORC
working vapor withdrawn from the turbine condenses into a working
liquid by iderect heat transfer with ambient air or water, a pump
which pumps the liquid of the ORC working liquid to a higher
pressure, a heat recovery heat exchanger which is supplied by a
heat carrier in order to conduct indirect heat transfer between a
low temperature heat source and the ORC working liquid. a heat
exchanger which is a ARC condenser supplied by an ARC refrigerant
vapor in order to conduct indirect heat transfer between the ORC
working liquid and a said ARC condensing refrigerant vapor an
evaporator which in inderect heat transfer with a heat carrier of a
high temperature source of heat generates saturated or superheated
ORC working vapor further supplied to the turbine [0012] components
of an Absorption Refrigeration Cycle (ARC) including a refrigerant,
for instance ammonia, hydrocarbons or others, an absorption
refrigeration machine which receives heat and vaporizes an ARC
refrigerant from mixture of liquids to produce a refrigerant vapor,
an ARC condenser heating in indirected heat transfer ORC working
liquid, an expansion valve reducing pressure of refrigerant liquid
passing from ARC condenser to evaporator and [0013] an additional
heat transfer component, which may be a countercurrent heat
exchnager, increasing in indirect heat transfer a temperature
difference between the ORC condensate and the heat carrier from the
low temperature heat source.
[0014] Another feature of the present invention resides, briefly
stated, in a method of energy recovery from low temperature sources
of heat, comprising the steps of: [0015] in an Organic Renkine
Cycle (ORC): Circulating an ORC working medium, for instance
ammonia, hydrofluorocarbons, chlorofluorocarbons or others, which
repeatedly changes its thermodinamic state from working liquid to
working vapor and from working vapor to working liquid depending on
working temperatures and pressure of the said ORC medium. (a
working liquid leaving a condenser called condensate) [0016]
withdrawing an ORC working vapor from a turbine into a condenser
condensing the ORC working vapor withdrawn from the turbine into an
ORC condenser, cooling the ORC condensate by indirect heat transfer
with ARC evaporating refrigerant, heating the ORC working liquid or
evaporating it by indirect heat trasfer in the ARC condenser in
order to generate ORC working vapor which is supplied to the
turbine; optional supplying a heat carrier from a high temperature
heat source to evaporate or superheat the said ORC working liquid
[0017] in an absorption refrigeration cycle (ARC): Circulating an
ARC refrigerant, for instance ammonia, hydrofluorocarbons,
chlorofluorocarbons or others, which repeatedly changes its
thermodinamic state from a refrigerant liquid to a refrigerant
vapor and from a refrigerant vapor to a refrigerant liquid
depending on working temperatures and pressure of the said ARC
medium. Vaporizing an ARC refrigerant from mixture of liquids in
absorption refrigeration machine which receives heat, in suppling
ARC vapor in the ARC condenser in order to heat the ORC working
liquid in in inderect heat transfer; in additional heat transfer
component, [0018] increasing a temperature difference between the
condensate of the ORC working medium and the heat carrier from the
low temperature heat source.
[0019] When the system is designed and a method is performed in
accordance with the present invention, they eliminate the
disadvantages of the prior art and provide the corresponding highly
advantageous results.
[0020] The novel features which are considered as characteristic
for the present invention are set forth in particular in the
appended claims. The invention itself, however, both as to its
construction and its method of operation, together with additional
objects and advantages thereof, will be best understood from the
following description of specific embodiments when read in
connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a view showing a system of energy recovery from
low temperature heat sources which implements a method in
accordance with the present invention;
[0022] FIG. 2 is a view showing a system of energy recovery from
low temperature heat sources which implements a method, in
accordance with a further embodiment of the present invention;
[0023] FIG. 3 is a view showing a temperature distribution in a
known ORC where a temperature difference T2 between a condensate
and a low temperature heat source is relatively low as known in the
art; and
[0024] FIG. 4 is a view showing the temperature distribution in the
inventive system and method of the ORC and ARC Cycle where a
temperature difference T2 between the ORC condensate and a low
temperature heat source is significantly increased.
[0025] The temperature difference .DELTA.T1 depends on the inlet
temperature of the heat carrier from the low temperature heat
source.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] A system of energy recovery from low temperature sources of
heat which implements a method in accordance with the present
invention, comprises components of an Organic Renkine Cyle and
components of Absorption Refrigeration Cycle.
[0027] The components of the Organic Renkine Cycle (ORC) include a
turbine 1 from which a working vapor of an ORC working medium is
withdrawn,
[0028] a condenser 2 in which the working vapor of the ORC working
medium withdrawn from the turbine condenses into a condensate,
[0029] a pump 3 which pumps the condensate of the ORC working
medium,
[0030] a heat recovery heat exchanger 4 which is supplied with a
heat carrier from a lower temperature heat source 5,
[0031] an ARC Condenser 6 in which the ORC working liquid is
heated,
[0032] and an ORC evaporator 11 in which the ORC working liquid
evaporates to produce ORC working vapor which is supplied to the
turbine 1,
[0033] The components of the Absorption Refrigeration Cycle (ARC)
include an absorption refrigeration machine 7 which receives heat
and vaporizes a n ORC refrigerant produce an ARC refrigerant vapor
which is supplied to the ARC condenser 6 to heat the ORC working
liquid, and an expansion valve reducing pressure of refrigerant
liquid passing from ARC condenser to evaporator
[0034] In accordance with the present invention, an additional
component 9 is provided, which increases a temperature difference
between the ORC condensate and the heat carrier from the low
temperature heat source.
The additional component 9 can be a heat exchanger in which the ORC
working liquid cooled by the ARC boiling refrigerant.
[0035] In the embodiment shown in FIG. 1 an additional heat source
8 can supply heat to the absorpotion refrigeration machine 7 to
evaporate the ARC liquid refrigerant.
[0036] An optional ORC regenerator 10 can connect the additional
component 9 with the ARC condenser 6, in which the ORC working
liquid is further heated by the condensing ARC vapor
refrigerant.
[0037] An optional ORC evaporator 11 can be connected with the ARC
condenser 6 and the turbine to evaporate the ORC working liquid
coming from the said ARC condenser 6.
[0038] In the embodiment shown in FIG. 2, the turbine is connected
with the absorption refrigeration machine 7 so that the ORC working
vapor withdrawn from the turbine vaporizes the ARC refrigerant.
[0039] FIG. 3 shows a temperature difference .DELTA.T2 of the ORC
condensate and the heat carrier from the low temperature heat
source in accordance with the prior art, which temperature
difference is relatively low.
[0040] FIG. 4 shows a temperature difference .DELTA.T2 of the ORC
condensate and the heat carrier from the low temperature heat
source in accordance with the present invention. It can be seen
that the temperature difference .DELTA.T2 in the system and method
of the present invention is greater than the temperature difference
.DELTA.T2 in the system and method in accordance with the prior
art.
[0041] The temperature difference .DELTA.T1 depends on the inlet
temperature of the heat carrier from the low temperature heat
source.
[0042] It will be understood that each of the elements described
above, or two or more together, may also find a useful application
in other types of methods and constructions differing from the
types described above.
[0043] While the invention has been illustrated and described as
embodied in a system and method of energy recovery from low
temperatire sources of heat, it is not intended to be limited to
the details shown, since various modifications and structural
changes may be made without departing in any way from the spirit of
the present invention.
[0044] Without further analysis, the foregoing will so fully reveal
the gist of the present invention that others can, by applying
current knowledge, readily adapt it for various applications
without omitting features that, from the standpoint of prior art,
fairly constitute essential characteristics of the generic or
specific aspects of this invention.
[0045] What is claimed as new and desired to be protected by
Letters Patent is set forth in the appended claims.
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