U.S. patent application number 12/675791 was filed with the patent office on 2011-01-06 for method and device for converting thermal energy into mechanical energy.
Invention is credited to Thomas Hauer, Jorg Lengert, Markus Neefischer, Reinhold Striegel.
Application Number | 20110000205 12/675791 |
Document ID | / |
Family ID | 40387915 |
Filed Date | 2011-01-06 |
United States Patent
Application |
20110000205 |
Kind Code |
A1 |
Hauer; Thomas ; et
al. |
January 6, 2011 |
METHOD AND DEVICE FOR CONVERTING THERMAL ENERGY INTO MECHANICAL
ENERGY
Abstract
When converting thermal into mechanical energy by a working
medium containing a mixture of at least two materials having
different boiling and condensation points, which is fed to a
condenser, and is condensed therein, the condenser condensation
pressure may increase and the efficiency for generating the
mechanical energy thus decreases because the mixture of materials
is separated into a liquid phase and a vapor phase upstream of the
condenser. To prevent this, the liquid phase of the working medium
is mixed with the vapor phase of the working medium before or while
the working medium is condensed, thus once again creating a
homogeneous mixture of materials which condenses at a lower
pressure than the separated working medium, thereby preventing loss
of efficiency. This can be applied to the use of thermal energy
from low-temperature sources such as geothermal fluids, industrial
waste heat, or waste heat from internal combustion engines.
Inventors: |
Hauer; Thomas; (Poing,
DE) ; Lengert; Jorg; (Lonnerstadt-Ailsbach, DE)
; Neefischer; Markus; (Rosstal, DE) ; Striegel;
Reinhold; (Baiersdorf, DE) |
Correspondence
Address: |
King & Spalding LLP
401 Congress Avenue, Suite 3200
Austin
TX
78701
US
|
Family ID: |
40387915 |
Appl. No.: |
12/675791 |
Filed: |
August 21, 2008 |
PCT Filed: |
August 21, 2008 |
PCT NO: |
PCT/EP2008/060921 |
371 Date: |
September 16, 2010 |
Current U.S.
Class: |
60/511 |
Current CPC
Class: |
F01K 25/065
20130101 |
Class at
Publication: |
60/511 |
International
Class: |
F01K 21/04 20060101
F01K021/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2007 |
DE |
10 2007 041 458.9 |
Claims
1. A method for conversion of thermal energy to mechanical energy
using an agent which comprises a substance mixture having at least
two substances which have different boiling and condensation
temperatures, the method comprising the steps of: supplying the
agent which is expanded in an expansion device as a two-phase flow
with a liquid phase and a vapor phase to a condenser, in which it
is condensed, and mixing the liquid phase with the vapor phase in
the two-phase flow before or during the condensation of the agent
in the condenser.
2. The method according to claim 1, wherein for mixing in the
two-phase flow, the liquid phase is separated from the vapor phase,
and the separated liquid phase is then combined with the vapor
phase again, wherein the separated liquid phase is preferably
sprayed into the vapor phase for combination.
3. The method according to claim 2, wherein before being sprayed
in, the pressure of the separated liquid phase is increased to a
value which is higher than the pressure of the vapor phase.
4. The method according to claim 2, wherein the separation of the
liquid phase from the vapor phase is carried out immediately before
the condenser.
5. The method according to claim 1, wherein the mixing process is
carried out immediately before or in the condenser.
6. The method according to claim 1, wherein the agent passes
through at least the following method steps in a closed circuit
after the condensation: increasing the pressure of the agent,
producing a vapor phase of the agent by heat transfer from an
external heat source, and expanding the vapor phase and converting
its thermal energy to mechanical energy.
7. The method according to claim 6, wherein before the expansion of
the vapor phase of the agent, a liquid phase of the agent is
separated from the vapor phase, and the vapor phase is supplied
again after it has been expanded.
8. The method according to claim 6, wherein a geothermal fluid,
industrial waste heat or waste heat from an internal combustion
engine is used as the external heat source.
9. The method according to claim 1, wherein a mixture of ammonia
and water is used as the agent.
10. An apparatus for conversion of thermal energy to mechanical
energy using an agent which comprises a substance mixture with at
least two substances which have different boiling and condensation
temperatures, having a condenser for condensation of the agent,
wherein the agent, which is expanded in an expansion device, is in
the form of a two-phase flow with a liquid phase and a vapor phase
before it is supplied to the condenser, the apparatus comprising a
mixing device for mixing the liquid phase of the two-phase flow
with the vapor phase of the two-phase flow before or during the
condensation of the agent in the condenser.
11. The apparatus according to claim 10, wherein the mixing device
has a separator for separation of the liquid phase from the vapor
phase, and has at least one nozzle for spraying the separated
liquid phase into the vapor phase.
12. The apparatus according to claim 11, wherein the mixing device
has a pump, by means of which the pressure of the separated liquid
phase can be increased to a value which is higher than the pressure
of the vapor phase.
13. The apparatus according to claim 11, wherein the separator is
arranged immediately before the condenser in the flow direction of
the agent.
14. The apparatus according to claim 11, wherein the at least one
nozzle is arranged immediately before or in the condenser in the
flow direction of the agent.
15. The apparatus according to claim 10, wherein the agent can be
carried in a closed circuit in the apparatus, which closed circuit
has at least the following components after the condenser in the
flow direction of the agent: a pump for increasing the pressure of
the agent a heat exchanger for producing a vapor phase of the agent
by heat transfer from an external heat source, and an expansion
device for expansion of the vapor phase and conversion of its
thermal energy to mechanical energy.
16. The apparatus according to claim 15, wherein the circuit
additionally comprises a separator, which is arranged between the
heat exchanger and the expansion device, for separation of a liquid
phase of the agent from a vapor phase, and a combination means,
which is arranged between the expansion device and the mixing
device, for combination of the separated liquid phase and the
expanded vapor phase.
17. The apparatus according to claim 15, wherein the external heat
source is a geothermal flow, industrial waste heat or waste heat
from an internal combustion engine.
18. The apparatus according to claim 10, wherein the agent is a
mixture of ammonia and water.
19. The apparatus according to claim 15, wherein the expansion
device is a turbine.
20. A method for conversion of thermal energy to mechanical energy,
comprising the steps of: providing an agent which comprises a
substance mixture having at least two substances which have
different boiling and condensation temperatures, supplying the
agent which is expanded in an expansion device as a two-phase flow
with a liquid phase and a vapor phase to a condenser, in which it
is condensed, and mixing the liquid phase with the vapor phase in
the two-phase flow before or during the condensation of the agent
in the condenser.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. National Stage Application of
International Application No. PCT/EP2008/060921 filed Aug. 21,
2008, which designates the United States of America, and claims
priority to German Application No. 10 2007 041 458.9 filed Aug. 31,
2007, the contents of which are hereby incorporated by reference in
their entirety.
TECHNICAL FIELD
[0002] The invention relates to a method and apparatus for
conversion of thermal energy to mechanical energy.
BACKGROUND
[0003] A method such as this and an apparatus such as this are
known, for example, from WO 2005/100755 A1.
[0004] In recent years, widely differing technologies have been
developed for low-temperature heat sources with temperatures up to
a maximum of 400.degree. C., for example geothermal fluids or
industrial waste heat, which allow the heat from these sources to
be converted to mechanical and/or electrical energy with high
efficiency. In addition to the Rankine process which uses an
organic agent (Organic Rankine Cycle, ORC), the so-called Kalina
cycle process, in particular, is distinguished by considerably
higher efficiencies than the classical Rankine process. Various
circuits for widely differing applications have already been
developed on the basis of the Kalina cycle process. Instead of
using water, these circuits use a two-substance mixture (for
example of ammonia and water) as the agent, with the different
boiling and condensation temperatures of the two substances and the
non-isothermal boiling and condensation process of the mixture
resulting from this being exploited in order to increase the
efficiency of the circuit in comparison to a Rankine circuit.
[0005] A Kalina circuit such as this normally comprises at least
one pump for increasing the pressure of the agent, a heat exchanger
for producing a vapor phase of the agent by heat transfer from an
external heat source, for example a geothermal liquid or industrial
waste heat, and an expansion device, preferably a turbine, for
expansion of the vapor phase and conversion of its thermal energy
to mechanical energy. The expanded agent is then condensed in a
condenser with the aid of a coolant.
[0006] Even more components may be connected in the circuit in
order to improve the efficiency. For example--as disclosed in WO
2005/100755 A1--a separator can be arranged in the circuit between
the heat exchanger and the expansion device, by means of which any
liquid phase of the agent which is still present in the event of
any partial vaporization of the agent in the heat exchanger can be
separated from the vapor phase before being supplied to the
expansion device. The separated liquid phase can then be combined
with the expanded vapor phase by means of a mixing device which is
arranged in the circuit between the expansion device and the
condenser. Further heat exchangers can be provided in order to
transfer heat from the expanded agent to the agent before it is
supplied to the heat exchanger.
[0007] A Kalina circuit with an ammonia-water mixture as the agent
and which is known from EP 0756069 B1 additionally has a
distillation unit, which is arranged in the circuit between the
condenser and the pump, for separation of a weak ammonia liquid
from the agent flow. This weak ammonia liquid is supplied to the
agent that has been expanded in the turbine, before this agent is
supplied to the condenser.
[0008] As a result of partial condensation of the agent, the agent
may contain a continuously increasing proportion of the liquid
phase in a line connection between the expansion device and the
condenser. In addition, feeding a liquid phase of the agent, which
for example has been separated before the expansion device, into
the expanded vapor phase leads to an increase in the proportion of
the liquid phase in the agent before it is supplied to the
condenser. The increasing proportion of the liquid phase leads to
"demixing" of the substance mixture and to the formation of an
inhomogeneous, partially demixed two-phase flow in the line
connection.
[0009] For example, if the agent comprises an ammonia-water
mixture, then this results in an inhomogeneous, partially demixed,
two-phase flow in the line connection, comprising a saturated vapor
which is rich in ammonia and a condensate with little ammonia. In
consequence, the condenser is partially flooded with condensate
with little ammonia, and the ammonia vapor fills only the remaining
residue of the heat exchanger. The flooded component reduces the
effectiveness of the condenser. Furthermore, the condensation
pressure of the vapor which is rich in ammonia and which (for
example comprises 95% ammonia) is considerably higher than that of
a homogeneous water-ammonia mixture. The higher the condensation
pressure is in the condenser, the shallower, however, is the
pressure gradient to be dissipated across the turbine. In
consequence, the circuit generates less mechanical and/or
electrical power, with a poorer efficiency.
SUMMARY
[0010] According to various embodiments, a method can be developed
so as to make it possible to avoid such efficiency losses.
[0011] According to an embodiment, a method for conversion of
thermal energy to mechanical energy using an agent which comprises
a substance mixture having at least two substances which have
different boiling and condensation temperatures, wherein the agent
which is expanded in an expansion device is supplied as a two-phase
flow with a liquid phase and a vapor phase to a condenser, in which
it is condensed, may comprise the step of mixing the liquid phase
with the vapor phase in the two-phase flow before or during the
condensation of the agent in the condenser.
[0012] According to a further embodiment, for mixing in the
two-phase flow, the liquid phase can be separated from the vapor
phase, and the separated liquid phase is then combined with the
vapor phase again, wherein the separated liquid phase is preferably
sprayed into the vapor phase for combination. According to a
further embodiment, before being sprayed in, the pressure of the
separated liquid phase can be increased to a value which is higher
than the pressure of the vapor phase. According to a further
embodiment, the separation of the liquid phase from the vapor phase
can be carried out immediately before the condenser. According to a
further embodiment, the mixing process can be carried out
immediately before or in the condenser. According to a further
embodiment, the agent may pass through at least the following
method steps in a closed circuit after the condensation:
--increasing the pressure of the agent, --producing a vapor phase
of the agent by heat transfer from an external heat source,
and--expanding the vapor phase and converting its thermal energy to
mechanical energy. According to a further embodiment, before the
expansion of the vapor phase of the agent, a liquid phase of the
agent can be separated from the vapor phase, and the vapor phase
can be supplied again after it has been expanded. According to a
further embodiment, a geothermal fluid, industrial waste heat or
waste heat from an internal combustion engine can be used as the
external heat source. According to a further embodiment, a mixture
of ammonia and water can be used as the agent.
[0013] According to another embodiment, an apparatus for conversion
of thermal energy to mechanical energy using an agent which
comprises a substance mixture with at least two substances which
have different boiling and condensation temperatures, having a
condenser for condensation of the agent, wherein the agent, which
is expanded in an expansion device, is in the form of a two-phase
flow with a liquid phase and a vapor phase before it is supplied to
the condenser, may comprise a mixing device for mixing the liquid
phase of the two-phase flow with the vapor phase of the two-phase
flow before or during the condensation of the agent in the
condenser.
[0014] According to a further embodiment, the mixing device may
have a separator for separation of the liquid phase from the vapor
phase, and has at least one nozzle for spraying the separated
liquid phase into the vapor phase. According to a further
embodiment, the mixing device may have a pump, by means of which
the pressure of the separated liquid phase can be increased to a
value which is higher than the pressure of the vapor phase.
According to a further embodiment, the separator can be arranged
immediately before the condenser in the flow direction of the
agent. According to a further embodiment, the at least one nozzle
can be arranged immediately before or in the condenser in the flow
direction of the agent. According to a further embodiment, the
agent can be carried in a closed circuit in the apparatus, which
closed circuit has at least the following components after the
condenser in the flow direction of the agent: --a pump for
increasing the pressure of the agent; --a heat exchanger for
producing a vapor phase of the agent by heat transfer from an
external heat source, and--an expansion device, in particular a
turbine, for expansion of the vapor phase and conversion of its
thermal energy to mechanical energy. According to a further
embodiment, the circuit additionally may comprise a separator,
which is arranged between the heat exchanger and the expansion
device, for separation of a liquid phase of the agent from a vapor
phase, and a combination means, which is arranged between the
expansion device and the mixing device, for combination of the
separated liquid phase and the expanded vapor phase. According to a
further embodiment, the external heat source can be a geothermal
flow, industrial waste heat or waste heat from an internal
combustion engine. According to a further embodiment, the agent can
be a mixture of ammonia and water.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention as well as further refinements will be
explained in more detail in the following text with reference to
exemplary embodiments in the figures, in which:
[0016] FIG. 1 shows a circuit according to one particularly
embodiment,
[0017] FIG. 2 shows one example of demixing of a two-substance
mixture in a line connection,
[0018] FIG. 3 shows a mixing device with spraying in jointly for a
plurality of condensers,
[0019] FIG. 4 shows a mixing device with spraying directly into the
condensers, and
[0020] FIG. 5 shows a mixing device with separate spraying in for
each individual condenser.
DETAILED DESCRIPTION
[0021] The method according to various embodiments for conversion
of thermal energy to mechanical energy using an agent which
comprises a substance mixture having at least two substances which
have different boiling and condensation temperatures, wherein the
agent which is expanded in an expansion device is supplied as a
two-phase flow with a liquid phase and a vapor phase to a
condenser, in which it is condensed, provides that the liquid phase
is mixed with the vapor phase in the two-phase flow before or
during the condensation of the agent in the condenser.
[0022] This makes it possible to avoid demixing of the
two-substance mixture, allowing a homogeneous two-substance mixture
to be produced again in the two-phase flow. If the coolant average
temperature in the condenser remains constant, a homogeneous
two-substance mixture actually condenses at a lower pressure.
However a lower condensation pressure in the condenser results in
an increase in the pressure gradient to be dissipated across the
turbine, as a result of which more mechanical and/or electrical
power can be produced, at a higher efficiency.
[0023] The liquid phase can be mixed with the vapor phase very
easily by separating the liquid phase from the vapor phase in the
two-phase flow and then combining the separated liquid phase with
the vapor phase again. The separated liquid phase is in this case
preferably sprayed into the vapor phase.
[0024] Particularly good mixing of the liquid and the vapor phases
can in this case be achieved by increasing the pressure of the
separated liquid phase to a value which is higher than the pressure
of the vapor phase, in order to spray it in. The separated liquid
phase is therefore supplied to the vapor phase at an increased
pressure.
[0025] In this case, separation of the liquid phase from the vapor
phase is preferably carried out immediately before the condenser,
in order to avoid the two-substance mixture demixing again on its
way to the condenser.
[0026] The mixing process itself can likewise be carried out
immediately before the condenser, or else directly in the
condenser.
[0027] In this case, the agent advantageously passes through at
least the following method steps in a closed circuit after the
condensation: [0028] increasing the pressure of the agent, [0029]
producing a vapor phase of the agent by heat transfer from an
external heat source, and [0030] expanding the vapor phase and
converting its thermal energy to mechanical energy.
[0031] The agent can in this case be vaporized completely by the
heat transfer (that is to say only a vapor phase exists), or can be
only partially vaporized (that is to say a vapor phase and a liquid
phase exist). In the case of only partial vaporization, before the
expansion of the vapor phase, the liquid phase of the agent is
advantageously separated from the vapor phase, and the vapor phase
is supplied again after it has been expanded. The liquid phase
therefore bypasses an expansion device for expansion of the vapor
phase.
[0032] After expansion, the agent can be supplied to the condenser
directly or via one or more intermediate heat exchangers, which
transfer the heat from the expanded vapor phase to the agent before
its at least partial vaporization.
[0033] A geothermal fluid, industrial waste heat or waste heat from
an internal combustion engine is preferably used as the external
heat source.
[0034] In this case, particularly high efficiencies can be achieved
if a mixture of ammonia and water is used as the agent. The
apparatus according to various embodiments for conversion of
thermal energy to mechanical energy using an agent which comprises
a substance mixture with at least two substances which have
different boiling and condensation temperatures, comprises a
condenser for condensation of the agent, wherein the agent, which
is expanded in an expansion device, is in the form of a two-phase
flow with a liquid phase and a vapor phase before it is supplied to
the condenser, and a mixing device for mixing the liquid phase of
the two-phase flow with the vapor phase of the two-phase flow
before or during the condensation of the agent in the
condenser.
[0035] The mixing device advantageously has a separator for
separation of the liquid phase from the vapor phase, and
advantageously has at least one nozzle for spraying the separated
liquid phase into the vapor phase.
[0036] If the mixing device has a pump, by means of which the
pressure of the separated liquid phase can be increased to a value
which is higher than the pressure of the vapor phase, particularly
good mixing of the two phases can be achieved when it is sprayed
in.
[0037] If the separator is arranged immediately before the
condenser in the flow direction of the agent, it is possible to
avoid the two-substance mixture demixing again on its way to the
condenser.
[0038] The at least one nozzle may itself likewise be arranged
immediately before or else in the condenser in the flow direction
of the agent.
[0039] According to one embodiment, the agent can be carried in a
closed circuit in the apparatus, which closed circuit has at least
the following components after the condenser in the flow direction
of the agent: [0040] a pump for increasing the pressure of the
agent [0041] a heat exchanger for producing a vapor phase of the
agent by heat transfer from an external heat source, and [0042] an
expansion device, in particular a turbine, for expansion of the
vapor phase and conversion of its thermal energy to mechanical
energy. In this case, the agent may be completely vaporized by the
heat transfer (that is to say only a vapor phase exists) or only
partially vaporized (that is to say a vapor phase and a liquid
phase exist). In the case of only partial vaporization, the circuit
advantageously also comprises a separator, which is arranged
between the heat exchanger and the expansion device, for separation
of a liquid phase from the vapor phase, and a combination means,
which is arranged between the expansion device and the mixing
device, for combination of the separated liquid phase and the
expanded vapor phase. In this case, the liquid phase can in this
way bypass the expansion device. The heat source is preferably a
geothermal fluid, industrial waste heat or waste heat from an
internal combustion engine. The agent is advantageously a mixture
of ammonia and water.
[0043] An apparatus 1 as shown in FIG. 1 for conversion of thermal
energy to mechanical energy comprises a circuit 2 in which a pump 3
for increasing the pressure of the agent, a heat exchanger 4 for
producing a vapor phase of the agent by heat transfer from an
external heat source 5, a turbine 6 for expansion of the vapor
phase of the agent and conversion of its thermal energy to
mechanical energy, a mixing device 7 for mixing a liquid and a
vapor phase of the agent and a condenser for complete condensation
of the agent with the aid of a coolant 9 are arranged successively
as major components in the flow direction of an agent. By way of
example, the external heat source 5 is a geothermal fluid,
industrial waste heat or waste heat from an internal combustion
engine. By way of example, the turbine 6 drives a generator, which
is not illustrated but converts the mechanical energy to electrical
energy.
[0044] The agent comprises a substance mixture having at least two
substances which have different boiling and condensation
temperatures. The following text is based on the assumption that a
mixture of ammonia and water is used as the agent.
[0045] As further components, the circuit 2 comprises a separator
15, which is arranged between the heat exchanger 4 and the turbine
6, for separation of a liquid phase of the agent from the vapor
phase, and a combination means 16, which is arranged between the
turbine 6 and the mixing device 7, for combination of the separated
liquid phase and the expanded vapor phase.
[0046] During operation of the circuit 2, the agent is exclusively
in the form of a liquid after the condenser 8. The liquid agent is
raised to a higher pressure by means of the pump 3 and is then at
least partially vaporized in the heat exchanger 4, that is to say
the agent exists in a vapor phase and possibly a liquid phase with
little ammonium after the heat exchanger. The liquid phase which
may possibly still be present is separated from the vapor phase in
the separator 15.
[0047] The vapor phase is expanded in the turbine 6, and its
thermal energy is converted to mechanical energy. The mechanical
energy can then be used further, for example for electricity
generation.
[0048] The vapor phase, which has now been expanded, is combined
again with the liquid phase, which was possibly previously
separated, in the combination means 16.
[0049] Because of partial condensation of the expanded vapor phase
and possibly liquid phase supplied via the combination means 16 the
proportion of liquid in the ammonium-water mixture will increase in
the line connection 10 between the turbine 6 and the condenser 8,
with demixing taking place into saturated vapor 11 which is rich in
ammonia, and condensate 12 with little ammonia (see FIG. 2). The
condenser 8 would therefore be supplied with an inhomogeneous,
partially demixed agent flow. This would result in the condenser 8
being partially flooded with the condensate 12 with little ammonia,
with the saturated vapor 11 which is rich in ammonia filling the
rest of the condenser. The flooded component would decrease the
effectiveness of the condenser and would therefore increase the
condensation pressure, since the condensation pressure of the
saturated vapor which is rich in ammonia (approximately 95%
ammonia) is considerably higher than that of a homogeneous
water-ammonia mixture. As the condensation pressure rises in the
condenser, however, the pressure gradient to be dissipated across
the turbine decreases, and therefore the mechanical and/or
electrical power which can be produced also decreases.
[0050] In order to avoid such efficiency losses, the circuit 2 has
a mixing device 7. The mixing device 7 comprises a separator 20 for
separation of the liquid phase with little ammonia from the vapor
phase which is rich in ammonia, and a nozzle 21 for spraying the
separated liquid phase into the vapor phase, wherein the separator
20 and the nozzle 21 are arranged successively in the connecting
line 10, between the turbine 6 and the condenser 8 and after the
combination means 16, in the flow direction of the agent. The
liquid phase which is separated in the separator 20 is supplied via
a bypass line 14 to the nozzle 21. A pump 22 and a control valve 23
are connected in the bypass line 14.
[0051] The pump 22 makes it possible to increase the pressure on
the separated liquid phase which carried in the bypass line 14 to a
value which is higher than the pressure of the vapor phase after
the separator 20. The amount of liquid phase supply to the nozzle
21 can be controlled by means of the control valve 23.
[0052] The separator 20 is arranged immediately before the
condenser 8 in the flow direction of the agent, in order to avoid
demixing of the agent again on the rest of its way to the condenser
8. The nozzle 21 can be arranged immediately before or in the
condenser 8, in the flow direction of the agent.
[0053] The separator 20 therefore separates the vapor phase which
is rich in ammonia, from the liquid phase, with little ammonia.
[0054] The liquid phase, with little ammonia is passed to the
nozzle 21 via the bypass line 14. In this case, the pump 22
increases the pressure of the liquid phase with little ammonia to a
value which is higher than the pressure of the vapor phase which is
rich in ammonia. The liquid phase with little ammonia is thus
sprayed at an increased pressure into the vapor phase, which is
rich in ammonia in the nozzle 21. This once again results in a
homogeneous ammonia-water mixture being able to be produced and
being able to be supplied to the condenser 8, which mixture
actually condenses at a lower pressure than the vapor phase, which
is rich in ammonia, assuming that the cooling temperature in the
condenser remains constant. However, with a lower condensation
pressure in the condenser, the pressure gradient to be dissipated
across the turbine rises, and the circuit can therefore produce
more electrical power, at a higher efficiency.
[0055] When there are a plurality of condensers 8 connected in
parallel in the flow direction of the agent--as illustrated in FIG.
3--a mixing device 7 can be provided with a single separator 20 and
a single nozzle 21 for all the condensers 8. The separator 20 and
the nozzle 21 are then preferably arranged immediately before the
condensers 8. The liquid phase is therefore sprayed jointly into
the vapor phase for all the condensers 8.
[0056] Alternatively, when there are a plurality of condensers 8
which are connected in parallel in the flow direction of the agent,
it is also possible to provide a mixing device 7 with a single
separator 20 and in each case one or more nozzles 21 for each of
the condensers 8. In the exemplary embodiment shown in FIG. 4, the
separator 20 is arranged immediately in front of the condensers 8,
and the nozzles 21 are arranged in the condensers 8. The liquid
phase is therefore sprayed directly into the condensers 8. In this
case, the supply of the liquid phase to the nozzles 21 can be
controlled by means of a joint control valve 23.
[0057] However, as illustrated in FIG. 5, the nozzles 21 can also
be arranged immediately before the respective condensers 8, that is
to say the spraying-in process is carried out separately for each
individual condenser 8. In this case, supply of the liquid phase to
each of the nozzles 21 can be controlled by means of a separate
control valve 23 for each of the condensers 8.
* * * * *