U.S. patent application number 11/238173 was filed with the patent office on 2007-03-29 for system and apparatus for power system utilizing wide temperature range heat sources.
This patent application is currently assigned to KALEX LLC. Invention is credited to Alexander I. Kalina.
Application Number | 20070068161 11/238173 |
Document ID | / |
Family ID | 37892194 |
Filed Date | 2007-03-29 |
United States Patent
Application |
20070068161 |
Kind Code |
A1 |
Kalina; Alexander I. |
March 29, 2007 |
SYSTEM AND APPARATUS FOR POWER SYSTEM UTILIZING WIDE TEMPERATURE
RANGE HEAT SOURCES
Abstract
A new method, system and apparatus for power system utilizing
wide temperature range heat sources and a multi-component working
fluid is disclosed including a heat recovery vapor generator (HRVG)
subsystem, a multi-stage energy conversion or turbine (T) subsystem
and a condensation thermal compression subsystem (CTCSS) and where
one or more of the streams exiting the stages of the turbine
subsystem T are sent back through different portions of the HRVG to
be warmed and/or cooled before being forwarded to the next stage of
the turbine subsystem T. The turbine subsystem T includes at least
a high pressure turbine or turbine stage (HPT) and a low pressure
turbine or turbine stage (LPT) and preferably, an intermediate
pressure turbine or turbine stage (IPT).
Inventors: |
Kalina; Alexander I.;
(Hillsborough, CA) |
Correspondence
Address: |
ROBERT W STROZIER, P.L.L.C
PO BOX 429
BELLAIRE
TX
77402-0429
US
|
Assignee: |
KALEX LLC
|
Family ID: |
37892194 |
Appl. No.: |
11/238173 |
Filed: |
September 28, 2005 |
Current U.S.
Class: |
60/651 ;
60/645 |
Current CPC
Class: |
F01K 25/065
20130101 |
Class at
Publication: |
060/651 ;
060/645 |
International
Class: |
F01K 13/00 20060101
F01K013/00; F01K 25/08 20060101 F01K025/08 |
Claims
1. A bottoming cycle system comprising: a heat recovery vapor
generator subsystem HRVG including: a preheater section for
preheating a fully condensed, high pressure working fluid stream
with heat derived from a cool heat source stream to form a
preheated, high pressure working fluid stream and a spent heat
source stream; an intercooler section for vaporizing the preheated,
high pressure working fluid stream with heat derived from a cooled
heat source stream and a low pressure working fluid stream to form
a vaporized high pressure working fluid stream, a cooled low
pressure working fluid stream and the cool heat source stream; and
a superheater section for superheating the vaporized, high pressure
working fluid stream with heat derived from a hot heat source
stream to form a superheated, high pressure working fluid stream
and the cooled heat source stream; where the fully condensed, high
pressure working fluid stream is preheated, vaporized and
superheated to form the superheated, high pressure working fluid
stream within the HRVG; a multi-stage energy conversion or turbine
subsystem T including: a high pressure turbine or turbine stage HPT
for converting a portion of thermal energy in the superheated
working fluid stream into a first portion of mechanical and/or
electrical power to form the low pressure, working fluid stream;
and a low pressure turbine or turbine stage LPT for converting a
portion of thermal energy in the cooled low pressure working fluid
stream into a second portion of mechanical and/or electrical power
to form a spent working fluid stream; and a condensation thermal
compression subsystem CTCSS for condensing the spent working fluid
stream to from the fully condensed, high pressure working fluid
stream.
2. The apparatus of claim 1, wherein the HRVG further includes: a
reheater or top section for reheating an intermediate pressure,
working fluid stream from the HPT with heat derived from the hot
heat source stream to from a heated, intermediate pressure stream,
and wherein the turbine subsystem T further includes: an
intermediate pressure turbine or turbine stage IPT interposed
between the HPT and the LPT for converting a portion of thermal
energy in the heated intermediate pressure, working fluid stream
into a third portion of mechanical and/or electrical power to form
the low pressure, working fluid stream.
3. The system of claim 1, wherein the CTCSS comprises a simple
condenser.
4. The system of claim 1, wherein the CTCSS comprises a plurality
of heat exchangers, at least one separators, a plurality of pumps,
a plurality of throttle valves, a plurality of mixing valves and a
plurality of combining valves arranged to efficiently convert the
spent working fluid stream into the fully condensed working fluid
stream by forming streams of different compositions, pressure and
temperature and using an external cooling stream to fully condense
the spent working fluid stream into the fully condensed working
fluid stream.
5. The system of claim 1, wherein the preheater comprises section
HR1 of the HRVG.
6. The system of claim 1, wherein the intercooler comprises
sections HR2 and HR3 of the HRVG.
7. The system of claim 1, wherein the superheater comprises
sections HR4 and HR5 of the HRVG.
8. The system of claim 2, wherein the reheater comprises section
HR5 of the HRVG.
9. The system of claim 1, wherein the working fluid is a
multi-component fluid.
10. The system of claim 1, wherein the multi-component fluid is
selected from the group consisting of an ammonia-water mixture, a
mixture of two or more hydrocarbons, a mixture of two or more
freons, and a mixture of hydrocarbons and freons.
11. The system of claim 1, wherein the composition of the incoming
multi-component stream comprises a mixture of water and
ammonia.
12. A method comprising the steps of: bringing a fully condensed,
high pressure working fluid stream into a first heat exchange
relationship with a cool heat source stream in a preheater of a
heat recovery vapor generator subsystem HRVG to form a spent heat
source stream and a preheated, high pressure working fluid stream;
bringing the preheated, high pressures working fluid stream into a
second heat exchange relationship with a cooled heat source stream
and a low pressure working fluid stream in an intercooler of the
IIRVG to form a vaporized, high pressure working fluid stream, the
cool heat source stream, and a cooled low pressure working fluid
stream; bringing the vaporized, high pressure working fluid stream
into a third heat exchange relationship with a hot heat source
stream in a superheater of the HRVG to form a superheated, high
pressure working fluid stream and the cooled heat source stream;
converting a portion of thermal energy in the superheated, high
pressure working fluid stream into a first portion of mechanical
and/or electrical power in a high pressure turbine or turbine stage
HPT of a turbine subsystem T to form the low pressure working fluid
stream; converting a portion of thermal energy in the cooled low
pressure working fluid stream into a second portion of mechanical
and/or electrical power in a low pressure turbine or turbine stage
LPT of a turbine subsystem T to form a spent working fluid stream;
and condensing the spent working fluid stream in a condensation
thermal compression subsystem CTCSS to form the fully condensed,
high pressure working fluid stream, where the fully condensed, high
pressure working fluid stream is preheated, vaporized and
superheated to form the superheated, high pressure working fluid
stream within the HRVG.
13. The method of claim 12, further comprising the steps of: prior
to the second converting step, reheating an intermediate pressure
working fluid stream from the HPT in a reheater or top section of
the HRVG to form a heated, intermediate pressure working fluid
stream; and converting a portion of thermal energy in the heated
intermediate pressure working fluid stream into a third portion of
mechanical and/or electrical power in an intermediate pressure
turbine or turbine stage IPT of a turbine subsystem T to form the
low pressure working fluid stream.
14. The method of claim 12, wherein the preheater comprises section
HR1 of the HRVG.
15. The method of claim 12, wherein the intercooler comprises
sections HR2 and HR3 sections of the HRVG.
16. The method of claim 12, wherein the superheater comprises
section HR4 and HR5 sections of the HRVG.
17. The method of claim 12, wherein the working fluid is a
multi-component fluid.
18. The method of claim 12, wherein the multi-component fluid is
selected from the group consisting of an ammonia-water mixture, a
mixture of two or more hydrocarbons, a mixture of two or more
freons, and a mixture of hydrocarbons and freons.
19. The method of claim 12, wherein the composition of the incoming
multi-component stream comprises a mixture of water and
ammonia.
20. The method of claim 12, wherein the CTCSS comprises a simple
condenser.
21. The method of claim 12, wherein the CTCSS comprises a plurality
of heat exchangers, at least one separators, a plurality of pumps,
a plurality of throttle valves, a plurality of mixing valves and a
plurality of combining valves arranged to efficiently convert the
spent working fluid stream into the fully condensed working fluid
stream by forming streams of different compositions, pressure and
temperature and using an external cooling stream to fully condense
the spent working fluid stream into the fully condensed working
fluid stream.
22. The system of claim 1, wherein the CTCSS comprises: a
separation subsystem comprising a separator adapted to produce a
rich vapor stream and a lean liquid stream; a heat exchange
subsystem comprising three heat exchangers and two throttle control
valves adapted to mix a pressure adjusted first portion of the lean
liquid stream with an incoming stream to form a pre-basic solution
stream, to mix a pressure adjusted second portion of the lean
liquid stream with the pre-basic solution stream to form a basic
solution stream, to bring a first portion of a pressurized fully
condensed basic solution stream into a heat exchange relationship
with the pre-basic solution stream to form a partially condensed
basic solution stream; a first condensing and pressurizing
subsystem comprising a first condenser and a first pump adapted to
fully condense the partially condensed basic solution stream to
form a fully condensed basic solution stream and to pressurize the
fully condensed basic solution stream to form a pressurized fully
condensed working fluid stream; and a second condensing and
pressurizing subsystem comprising a second condenser and a second
pump adapted to mix a second portion of the fully condensed basic
solution stream and the rich vapor stream to form an outgoing
stream, to fully condense the outgoing stream and to pressurize the
outgoing stream to a desired high pressure, where the first portion
of the lean liquid stream is pressure adjusted to have the same or
substantially the same pressure as the incoming stream and where
the second portion of the lean stream is pressure adjusted to have
the same or substantially the same pressure as the pre-basic
solution stream and where the streams comprise at least one lower
boiling component and at least one higher boiling component and the
compositions of the streams are the same or different with the
composition of the incoming stream and the outgoing stream being
the same.
23. The method of claim 12, wherein the CTCSS comprises: a
separation subsystem comprising a separator adapted to produce a
rich vapor stream and a lean liquid stream; a heat exchange
subsystem comprising three heat exchangers and two throttle control
valves adapted to mix a pressure adjusted first portion of the lean
liquid stream with an incoming stream to form a pre-basic solution
stream, to mix a pressure adjusted second portion of the lean
liquid stream with the pre-basic solution stream to form a basic
solution stream, to bring a first portion of a pressurized fully
condensed basic solution stream into a heat exchange relationship
with the pre-basic solution stream to form a partially condensed
basic solution stream; a first condensing and pressurizing
subsystem comprising a first condenser and a first pump adapted to
fully condense the partially condensed basic solution stream to
form a fully condensed basic solution stream and to pressurize the
fully condensed basic solution stream to form a pressurized fully
condensed working fluid stream; and a second condensing and
pressurizing subsystem comprising a second condenser and a second
pump adapted to mix a second portion of the fully condensed basic
solution stream and the rich vapor stream to form an outgoing
stream, to fully condense the outgoing stream and to pressurize the
outgoing stream to a desired high pressure, where the first portion
of the lean liquid stream is pressure adjusted to have the same or
substantially the same pressure as the incoming stream and where
the second portion of the lean stream is pressure adjusted to have
the same or substantially the same pressure as the pre-basic
solution stream and where the streams comprise at least one lower
boiling component and at least one higher boiling component and the
compositions of the streams are the same or different with the
composition of the incoming stream and the outgoing stream being
the same.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a bottoming cycle system
for converting a portion of heat from a heat source stream,
especially, an exhaust stream from an internal combustion engine,
into usable mechanical and/or electrical power.
[0003] More particularly, the present invention relates to a
bottoming cycle system for converting a portion of heat from a heat
source stream, especially, an exhaust stream from an internal
combustion engine, into usable mechanical and/or electrical power,
where the system includes a heat recovery vapor generator (HRVG)
subsystem, a multi-stage energy conversion or turbine (T) subsystem
and a condensation thermal compression subsystem (CTCSS) and where
one or more of the streams exiting the stages of the turbine
subsystem T are sent back through different portions of the HRVG to
be warmed and/or cooled before being forwarded to the next stage of
the turbine subsystem T. The turbine subsystem T includes at least
a high pressure turbine or turbine stage (HPT) and a low pressure
turbine or turbine stage (LPT) and preferably, an intermediate
pressure turbine or turbine stage (IPT).
[0004] 2. Description of the Related Art
[0005] In U.S. Pat. Nos. 5,095,708 and 5,572,871, power systems
were presented that were designed to serve as bottoming cycles for
combined cycle systems. These systems both had a specific feature
which was the key to their high efficiency; both systems used
intercooling of the working fluid in between turbine stages.
Because the heat released during intercooling was recuperated, it
was then used as an additional source of heating for the process of
vaporization. This resulted in a drastic increase in the
thermodynamical reversibility and correspondingly in higher
efficiency of the power cycle.
[0006] However, in the prior art, this process of intercooling was
performed in a special heat exchanger, a so-called "intercooler."
Such an intercooler requires that the streams of working fluid in
both the tubes and the shell of the intercooler be at high
pressure. Moreover, the intercooled stream in the prior art is in
the form of a vapor, and therefore the heat transfer coefficient
from the vapor to the intercooler tubes is low. As a result, such
an intercooler must be a very large and very expensive high
pressure heat exchanger. This in turn has a very negative impact on
the economics of the entire system.
[0007] Thus, there is a need in the art for a system designed to
utilize heat from heat sources having a wide range of temperatures
and to convert a potion of energy from these heat sources into
mechanical and/or electrical power.
SUMMARY OF THE INVENTION
[0008] The present invention provides a bottoming cycle system
including a heat recovery vapor generator subsystem (HRVG), a
multi-stage energy conversion or turbine subsystem (T) and a
condensation thermal compression subsystem (CTCSS). The system is
designed so that one or more of the streams exiting the stages of
the turbine subsystem T are sent back through different portions of
the HRVG to be warmed and/or cooled before being forwarded to the
next stage of the turbine subsystem T. The turbine subsystem T
includes at least a high pressure turbine or turbine stage (HPT)
and a low pressure turbine or turbine stage (LPT) and preferably,
an intermediate pressure turbine or turbine stage (IPT).
[0009] The present invention also provides a bottoming cycle system
including a heat recovery vapor generator subsystem (HRVG), a
multi-stage energy conversion or turbine subsystem (T) and a
condensation thermal compression subsystem (CTCSS). The turbine
subsystem T includes a high pressure turbine or turbine stage
(HPT), an intermediate pressure turbine or turbine stage (IPT) and
a low pressure turbine or turbine stage (LPT). The HRVG includes
five sections. The lower middle two sections comprise an
intercooler and the top section comprises a reheater. The CTCSS can
be a simple condenser or a more complex condensation thermal
compression subsystem designed to more efficiently condense a
multi-component working fluid. The system is designed so that a
spent stream exiting the HPT of the turbine subsystem T is sent
back through a top section of the HRVG to be reheated and a spent
stream of the IPT is sent through the intercooler to provide
additional heat for vaporing the working fluid stream.
[0010] The present invention also provides a bottoming cycle system
including a heat recovery vapor generator subsystem (HRVG), a
multi-stage energy conversion or turbine subsystem (T) and a
condensation thermal compression subsystem (CTCSS). The turbine
subsystem T includes a high pressure turbine or turbine stage (HPT)
and a low pressure turbine or turbine stage (LPT). The HRVG
includes five sections. The lower middle two sections comprise an
intercooler. The CTCSS can be a simple condenser or a more complex
condensation thermal compression subsystem designed to more
efficiently condense a multi-component working fluid. The system is
designed so that a spent stream exiting the HPT of the turbine
subsystem T is through the intercooler to provide additional heat
for vaporing the working fluid stream.
[0011] The present invention also provides a method including the
step of pumping a fully condensed working fluid stream to a desired
high pressure. The high pressure stream is then fed into a first or
preheater section HR1 of a heat recovery vapor generator subsystem
HRVG where it is preheated by a cool heat source stream. The
preheated, high pressure stream is then forwarded successively
through a second section HR2 and a third section HR3 of the HRVG,
which comprise an intercooler, where the preheated, high pressure
stream is vaporized by a cooled heat source stream and a spent
intermediate pressure turbine or turbine stage (IPT) stream to form
a vaporized working fluid stream. The vaporized working fluid
stream is then superheated in a fourth section HR4 and a fifth
section HR5 of the HRVG to form a superheated working fluid stream
by a hot heat source stream. Simultaneously, a spent high pressure
turbine or turbine state (HPT) stream is reheated by the
superheated working fluid stream and the hot heat source stream.
The superheated working fluid stream is then sent through an
admission valve and into the high pressure turbine HPT, where a
portion of its thermal energy is converted to mechanical and/or
electrical power. The spent HPT stream, which has been reheated, is
then sent into the intermediate pressure turbine or turbine stage
IPT, where a portion of its thermal energy is converted to
mechanical and/or electrical power. The spent IPT stream after
passing through the intercooler where it is cooled is sent through
a low pressure turbine or turbine stage LPT, where a portion of its
thermal energy is converted to mechanical and/or electrical power.
The spent LPT stream is then forwarded to a a condensation thermal
compression subsystem (CTCSS), where it is fully condensed.
[0012] The present invention also provides a method including the
step of pumping a fully condensed working fluid stream to a desired
high pressure. The high pressure stream is then fed into a first or
preheater section HR1 of a heat recovery vapor generator subsystem
HRVG where it is preheated by a cool heat source stream. The
preheated, high pressure stream is then forwarded successively
through a second section HR2 and a third section HR3 of the HRVG,
which comprise an intercooler, where the preheated, high pressure
stream is vaporized by a cooled heat source stream and a spent high
pressure turbine or turbine stage (HPT) stream to form a vaporized
working fluid stream. The vaporized working fluid stream is then
superheated in a fourth section HR4 and a fifth section HR5 of the
HRVG to form a superheated working fluid stream by a hot heat
source stream. The superheated working fluid stream is then sent
through an admission valve and into the high pressure turbine HPT,
where a portion of its thermal energy is converted to mechanical
and/or electrical power. The spent HPT stream after passing through
the intercooler where it is cooled is sent through a low pressure
turbine or turbine stage LPT, where a portion of its thermal energy
is converted to mechanical and/or electrical power. The spent LPT
stream is then forwarded to a a condensation thermal compression
subsystem (CTCSS), where it is fully condensed.
[0013] A bottoming cycle system including a heat recovery vapor
generator subsystem HRVG including: (1) a preheater section for
preheating a fully condensed, high pressure working fluid stream
with heat derived from a cool heat source stream to form a
preheated, high pressure working fluid stream and a spent heat
source stream; (2) an intercooler section for vaporizing the
preheated, high pressure working fluid stream with heat derived
from a cooled heat source stream and a low pressure working fluid
stream to form a vaporized, high pressure working fluid stream, a
cooled low pressure working fluid stream and the cool heat source
stream; (3) a superheater section for superheating the vaporized,
high pressure working fluid stream with heat derived from a hot
heat source stream to form a superheated, high pressure working
fluid stream and the cooled heat source stream. The system also
includes a multi-stage energy conversion or turbine subsystem T
including: (1) a high pressure turbine or turbine stage HPT for
converting a portion of thermal energy in the superheated working
fluid stream into a first portion of mechanical and/or electrical
power to form the low pressure, working fluid stream; and (2) a low
pressure turbine or turbine stage LPT for converting a portion of
thermal energy in the cooled low pressure working fluid stream into
a second portion of mechanical and/or electrical power to form a
spent working fluid stream. The system further includes a
condensation thermal compression subsystem CTCSS for condensing the
spent working fluid stream to from the fully condensed, high
pressure working fluid stream.
[0014] A bottoming cycle system including a heat recovery vapor
generator subsystem HRVG including: wherein the HRVG further
includes: (1) a preheater section for preheating a fully condensed,
high pressure working fluid stream with heat derived from a cool
heat source stream to form a preheated, high pressure working fluid
stream and a spent heat source stream; (2) an intercooler section
for vaporizing the preheated, high pressure working fluid stream
with heat derived from a cooled heat source stream and a low
pressure working fluid stream to form a vaporized, high pressure
working fluid stream, a cooled low pressure working fluid stream
and the cool heat source stream; (3) a superheater section for
superheating the vaporized, high pressure working fluid stream with
heat derived from a hot heat source stream to form a superheated,
high pressure working fluid stream and the cooled heat source
stream; and (4) a reheater or top section for reheating an
intermediate pressure, working fluid stream from the HPT with heat
derived from the hot heat source stream to from a heated,
intermediate pressure stream. The system also includes a
multi-stage energy conversion or turbine subsystem T including: (1)
a high pressure turbine or turbine stage HPT for converting a
portion of thermal energy in the superheated working fluid stream
into a first portion of mechanical and/or electrical power to form
the low pressure, working fluid stream; (2) an intermediate
pressure turbine or turbine stage IPT interposed between the HPT
and the LPT for converting a portion of thermal energy in the
heated intermediate pressure, working fluid stream into a third
portion of mechanical and/or electrical power to form the low
pressure, working fluid stream; and (3) a low pressure turbine or
turbine stage LPT for converting a portion of thermal energy in the
cooled low pressure working fluid stream into a second portion of
mechanical and/or electrical power to form a spent working fluid
stream. The system further includes a condensation thermal
compression subsystem CTCSS for condensing the spent working fluid
stream to from the fully condensed, high pressure working fluid
stream.
[0015] A method including the steps of bringing a fully condensed,
high pressure working fluid stream into a first heat exchange
relationship with a cool heat source stream in a preheater of a
heat recovery vapor generator subsystem HRVG to form a spent heat
source stream and a preheated, high pressure working fluid stream.
The preheated, high pressure working fluid stream is then brought
into a second heat exchange relationship with a cooled heat source
stream and a low pressure working fluid stream in an intercooler of
the HRVG to form a vaporized, high pressure working fluid stream,
the cool heat source stream, and a cooled low pressure working
fluid stream. The vaporized, high pressure working fluid stream is
then brought into a third heat exchange relationship with a hot
heat source stream in a superheater of the HRVG to form a
superheated, high pressure working fluid stream and the cooled heat
source stream. A portion of thermal energy in the superheated, high
pressure working fluid stream is then converted into a first
portion of mechanical and/or electrical power in a high pressure
turbine or turbine stage HPT of a turbine subsystem T to form the
low pressure working fluid stream. A portion of thermal energy in
the cooled low pressure working fluid stream is then converted into
a second portion of mechanical and/or electrical power in a low
pressure turbine or turbine stage LPT of a turbine subsystem T to
form a spent working fluid stream. Finally, the spent working fluid
stream is fully condensed in a condensation thermal compression
subsystem CTCSS to form the fully condensed, high pressure working
fluid stream.
[0016] A method including the steps of bringing a fully condensed,
high pressure working fluid stream into a first heat exchange
relationship with a cool heat source stream in a preheater of a
heat recovery vapor generator subsystem HRVG to form a spent heat
source stream and a preheated, high pressure working fluid stream.
The preheated, high pressure working fluid stream is then brought
into a second heat exchange relationship with a cooled heat source
stream and a low pressure working fluid stream in an intercooler of
the HRVG to form a vaporized, high pressure working fluid stream,
the cool heat source stream, and a cooled low pressure working
fluid stream. The vaporized, high pressure working fluid stream is
then brought into a third heat exchange relationship with a hot
heat source stream in a superheater of the HRVG to form a
superheated, high pressure working fluid stream and the cooled heat
source stream. A portion of thermal energy in the superheated, high
pressure working fluid stream is then converted into a first
portion of mechanical and/or electrical power in a high pressure
turbine or turbine stage HPT of a turbine subsystem T to form the
low pressure working fluid stream. An intermediate pressure working
fluid stream from the HPT is then reheated in a reheater or top
section of the HRVG to form a heated, intermediate pressure working
fluid stream. A portion of thermal energy in the heated
intermediate pressure working fluid stream is then converted into a
third portion of mechanical and/or electrical power in an
intermediate pressure turbine or turbine stage IPT of a turbine
subsystem T to form the low pressure working fluid stream. A
portion of thermal energy in the cooled low pressure working fluid
stream is then converted into a second portion of mechanical and/or
electrical power in a low pressure turbine or turbine stage LPT of
a turbine subsystem T to form a spent working fluid stream.
Finally, the spent working fluid stream is fully condensed in a
condensation thermal compression subsystem CTCSS to form the fully
condensed, high pressure working fluid stream.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention can be better understood with reference to the
following detailed description together with the appended
illustrative drawings in which like elements are numbered the
same:
[0018] FIG. 1 depicts a block diagram of a preferred embodiment a
power system of this invention;
[0019] FIG. 2 depicts a block diagram of another preferred
embodiment a power system of this invention;
[0020] FIG. 3 depicts a block diagram of a preferred embodiment of
CTCSS Variant 1a of a condensation and thermal compression
subsystems;
[0021] FIG. 4 depicts a block diagram of another preferred
embodiment of CTCSS Variant 1b of a condensation and thermal
compression subsystems;
[0022] FIG. 5 depicts a block diagram of a preferred embodiment of
CTCSS Variant 2a of a condensation and thermal compression
subsystems;
[0023] FIG. 6 depicts a block diagram of a preferred embodiment of
CTCSS Variant 2b of a condensation and thermal compression
subsystems;
[0024] FIG. 7 depicts a block diagram of a preferred embodiment of
CTCSS Variant 3a of a condensation and thermal compression
subsystems;
[0025] FIG. 8 depicts a block diagram of a preferred embodiment of
CTCSS Variant 3b of a condensation and thermal compression
subsystems;
[0026] FIG. 9 depicts a block diagram of a preferred embodiment of
CTCSS Variant 4a of a condensation and thermal compression
subsystems;
[0027] FIG. 10 depicts a block diagram of a preferred embodiment of
CTCSS Variant 4b of a condensation and thermal compression
subsystems;
[0028] FIG. 11 depicts a block diagram of a preferred embodiment of
CTCSS Variant 5a of a condensation and thermal compression
subsystems;
[0029] FIG. 12 depicts a block diagram of a preferred embodiment of
CTCSS Variant 5b of a condensation and thermal compression
subsystems;
DETAILED DESCRIPTION OF THE INVENTION
[0030] The inventors have found a new bottoming system can be
constructed using a heat recovery vapor generator (HRVG) subsystem,
a multi-stage energy conversion subsystem and a condensation
thermal compression subsystem (CTCSS), where one or more of the
streams exiting the stages are set back through different portions
of the HRVG to be warmed before being forwarded to the next stage.
The multi-stage energy conversion or turbine (T) subsystem includes
at least a high pressure turbine and a low pressure turbine and
preferably, an intermediate pressure turbine. Unlike the prior are
systems, where the intercooler was a specialized separate piece of
equipment with fairly high pressure drops, the intercooler of this
system is built into the HRVG reducing pressure drops, while
maintaining overall efficiency of 0.9982% of the prior art, yet
increasing power output due to better utilization of the heat in
the heat source, i.e., the heat source stream is cooled to a low
temperature in the present system than in the prior art.
[0031] The system of this invention is designed to utilize heat
from heat sources having a wide range of temperatures and is
designed to convert the energy of these heat sources into
mechanical and/or electrical power.
[0032] The system of this invention is designed to be utilized as a
bottoming cycle in a combined cycle power system, i.e., to utilize
a hot exhaust stream as a heat source for example from a gas
turbine. This system can also be used with any other heat source
having a suitable temperature range.
[0033] The present invention broadly relates to a bottoming cycle
system including a heat recovery vapor generator subsystem HRVG, a
multi-stage energy conversion or turbine subsystem T and a
condensation thermal compression subsystem CTCSS. The turbine
subsystem T includes a high pressure turbine or turbine stage HPT
and a low pressure turbine or turbine stage LPT and optionally, an
intermediate pressure turbine or turbine stage IPT. The HRVG
includes five sections. The lower middle two sections comprise an
intercooler and optionally, a reheater section. The CTCSS can be a
simple condenser or a more complex condensation thermal compression
subsystem designed to more efficiently condense a multi-component
working fluid. The system is designed so that a spent stream
exiting the HPT of the turbine subsystem T is through the
intercooler to provide additional heat for vaporing the working
fluid stream and optionally, to forward a spent HPT stream to the
reheater section and then to the IPT, which is in turn forwarded to
the intercooler instead of the spent HPT stream.
[0034] The present invention broadly relates to a method including
the step of pumping a fully condensed working fluid stream to a
desired high pressure. The high pressure stream is then fed into a
first or preheater section HR1 of a heat recovery vapor generator
subsystem HRVG, where it is preheated by a cool heat source stream.
The preheated, high pressure stream is then forwarded successively
through a second section HR2 and a third section HR3 of the HRVG,
which comprise an intercooler, where the preheated, high pressure
stream is vaporized by a cooled heat source stream and a spent high
pressure turbine or turbine stage HPT stream to form a vaporized
working fluid stream. The vaporized working fluid stream is then
superheated in a fourth section HR4 and a fifth section HR5 of the
HRVG to form a superheated working fluid stream by a hot heat
source stream. The superheated working fluid stream is then sent
through into the high pressure turbine HPT, where a portion of its
thermal energy is converted to mechanical and/or electrical power.
The spent HPT stream after passing through the intercooler where it
is cooled is sent through a low pressure turbine or turbine stage
LPT, where a portion of its thermal energy is converted to
mechanical and/or electrical power. The spent LPT stream is then
forwarded to a a condensation thermal compression subsystem
(CTCSS), where it is fully condensed. Optionally, the superheated
working fluid stream is first sent through an admission valve and
then into the HPT. Optionally, the turbine subsystem includes an
intermediate pressure turbine or turbine stage IPT. In this
alternate variant, the spent HPT stream is sent through a reheater,
which comprises the fifth section HR5 of the HRVG, instead of to
the intercooler, and then into the IPT. A spent IPT stream then
replaces the spent HPT stream and is sent into the intercooler and
then into the LPT.
[0035] The working fluid used in the systems of this inventions
preferably is a multi-component fluid that comprises a lower
boiling point component fluid--the low-boiling component--and a
higher boiling point component--the high-boiling component.
Preferred working fluids include an ammonia-water mixture, a
mixture of two or more hydrocarbons, a mixture of two or more
freon, a mixture of hydrocarbons and freon, or the like. In
general, the fluid can comprise mixtures of any number of compounds
with favorable thermodynamic characteristics and solubility. In a
particularly preferred embodiment, the fluid comprises a mixture of
water and ammonia.
[0036] In the system of this invention, the process of intercooling
is performed in a heat recovery vapor generator (HRVG). A special
apparatus for intercooling is not required and as a result the
economics of the system is drastically improved.
[0037] Referring now to FIG. 1, a fully condensed working solution
stream S100 having parameters as at a point 29, corresponding a
state of saturated liquid at ambient temperature, is sent into a
feed pump FP, where it is pumped to a required high pressure to
form a working solution stream S102 having parameters as at a point
100. The pressure of the stream S102 having the parameters at the
point 100 can be lower or higher than the critical pressure of the
working fluid.
[0038] The stream S102 having the parameters as at the point 100
then enters into an initial heat exchange section or preheater
section HR1 of the HRVG. In the preheater section HR1 of the HRVG,
the stream S102 having the parameters as at the point 100 is heated
in counterflow by a low temperature heat source stream S104 having
parameters as at a point 608, usually a low temperature flue gas
stream, to form a working solution stream S106 having parameters as
at a point 101 and a spent heat source stream S108 having
parameters as at a point 609 in a heat exchange process 100-101 or
608-609. The stream S106 having the parameters as at the point 101
corresponds to a state of subcooled liquid.
[0039] Thereafter the stream S106 of working fluid having the
parameters as at the point 101, enters into a subsequent portion
HR2 of the HRVG, where further heating of the working fluid stream
is provided by the heat source stream and by heat released from the
intercooler as described below.
[0040] In this section HR2 of the HRVG, heat released from the
intercooler is actually heating the heat source gas. This heat is
then transferred from the heat source gas to the working fluid as
described below. The working fluid stream S106 having the
parameters as at the point 101 enters into the section HR2 of the
HRVG is first heated to a state of saturated liquid (or in case of
supercritical pressure, to critical temperature) in a heat exchange
process 101-111 or 610-608 with a heat source stream S110 having
parameters as at a point 610 forming a working fluid stream S112
having parameters as at a point 111 and the stream S104 having the
parameters as at the point 608. Thereafter, the working fluid S112
having the parameters as at the point 111 is either vaporized and
superheated (in cases of subcritical pressure) or is simply
superheated (in cases of supercritical pressure) in a third section
HR3 of the HRVG in a heat exchange process 111-102 or 607-610. In
either case, the stream S112 having the parameters as at the point
111 is heated with a heat source stream S114 having parameters as
at a point 607 to form a working fluid stream S116 having
parameters as at a point 102 and the heat source stream S110 having
parameters as at the point 610.
[0041] Simultaneously, an IPT spent working fluid stream S118
having parameters as at a point 107 enters into the intercooler
portion of the HRVG which comprises the HR2 and HR3 sections of the
HRVG to provide heat to the intercooler process. Upon entering the
HR3 section of the HRVG, the stream S118 having the parameters as
at the point 107 flows in counterflow to the stream S112 having the
parameters as at the point 111 and concurrent flow with the heat
source stream S114 having the parameters as at the 607. Thus, both
the stream S114 and S118 provide heat to the counterflow stream
S112 producing the working fluid stream S116 having the parameters
as at the point 102, a cooled IPT working fluid stream S120 having
parameters as at a point 110 and the heat source stream S110 having
the parameters as at the point 610 in a first intercool heat
exchange process 607-610, 102-111, or 107-110.
[0042] In the second section HR2 of the intercooler section of the
HRVG, the cooled IPT working fluid stream S120 having the
parameters as at the point 110 and the heat source stream S110
having the parameters as at the point 610 provide heat to the
working fluid stream S106 having the parameters as at the point
101. In the intercooler heat exchange processes 610-608, 101-111
and 110-108, the working fluid stream S106 having the parameters as
at the point 101, the cooled IPT working fluid stream S120 having
the parameters as at the point 110 and the heat source stream S110
having the parameters as at the point 610 produce the working fluid
stream S112 having the parameters as at the point 111, an initial
LPT working fluid stream S122 having the parameters as at the point
108 and the heat source stream S104 having the parameters as at the
point 608.
[0043] The total quantity of heat transferred to the working fluid
stream S106 in a combined heat exchange process 101-102 is equal to
a sum of heat released by the heat source in a combined heat
exchange process 607-608, and heat released by the intercooler in
process 107-108.
[0044] Thereafter, the working fluid stream S116 having the
parameters as at the point 102 is further heated in a fourth heat
exchange section HR4 of the HRVG by heat released from a
counterflow heat source stream S124 having parameters as at a point
605 forming a working fluid stream S126 having parameters as at a
point 103 as described below. The working fluid stream S126 having
the parameters as at the point 103 is then yet further heated in a
fifth section HR5 of the HRVG by a counterflow initial heat source
stream S128 having the parameters as at the point 600 forming a
fully vaporized and superheated working fluid stream S130 having
the parameters as at the point 104, corresponding to a state of
superheated vapor.
[0045] The superheated working fluid stream S130 having the
parameters as at the point 104 passes through an admission valve
TV1 to form an HPT addition stream S132 having the parameters as at
the point 109, and enters into a high pressure turbine stage HPT of
a turbine subsystem T. In the HPT, the HPT addition stream S132
having the parameters as at the point 109 is expanded to an
intermediate pressure, producing mechanical power and/or electrical
power, to form an HPT spent stream S134 having parameters as at a
point 106.
[0046] The HPT spent stream S134 having the parameters as at the
point 106 is then sent back into a high temperature section HR5,
the reheater section, of the HRVG, where it is reheated in
counterflow by the initial heat source stream S128 to form an
initial IPT working fluid stream S136 having parameters as at a
point 105. The heat released by the heat source stream S128 having
the parameters as at the point 600 in heat exchange process 600-605
is utilized by both the heat exchange process 103-104 (superheating
the high pressure stream of working fluid, see above) and the heat
exchange process 106-105 (reheating the intermediate pressure
stream of working fluid.)
[0047] The simultaneous heating and reheating of two streams S134
and S126 by the high temperature portion of the heat source stream
S128 is possible because the heat from this high temperature
portion of the heat source stream S128 is not used in the process
of vaporization of the working fluid. Instead the heat required for
vaporization of the working fluid S102 is supplied by the medium
temperature portions of the heat source stream S124, S10 and S104,
as well as by the heat released in the intercooler by the IPT spent
stream S118 as described above.
[0048] The reheated stream S136 of working fluid having the
parameters as at the point 105 enters into an intermediate pressure
turbine stage IPT of the turbine subsystem T, where it is expanded,
producing mechanical power and/or electrical power forming the
stream S118 having the parameters as at the point 107. The stream
S118 having the parameters as at the point 107, which is in a state
of superheated vapor, is then sent back into the HRVG (into the
intercooler sections HR3 and HR2 of the HRVG), where it passes
through tubes which are parallel to tubes through which the
upcoming high pressure working fluid stream S102 is flowing. In
this manner, streams S118 and S120 having the parameters as at the
points 107 and 101, respectively, passes in counterflow to the
streams S106 and S112 having the parameters as at the points 101 or
111, respectively, (see above) and simultaneously, in parallel flow
with the heat source streams S114 and S110 having the parameters as
at the point 607 and 610 (see above.)
[0049] The temperature of the working fluid streams S106 and S112
in the intercooler are always higher than the temperature of the
surrounding heat source streams S114 and S110. Therefore, while the
heat source stream is cooled by the upcoming stream of high
pressure working fluid streams S106 and S112, it is simultaneously
heated by the parallel streams S118 and S120 of working fluid in
the intercooler.
[0050] Note that stream S120 having the parameters as at the point
110 in the intercooler and the heat source stream S110 having the
parameters as at the point 610 correspond to the boiling point of
the stream S112 having the parameters as at the point 111 (or to
the critical point, in the case of supercritical pressure) of the
upcoming stream S106 of high pressure working fluid having the
parameters as at the point 101.
[0051] Meanwhile, the working fluid stream S122 having the
parameters as at the point 108, corresponding to a state of
superheated vapor, and is sent into a low pressure turbine stage
LPT of the turbine T, where it is fully expanded, producing
mechanical power and/or electrical power, forming a spent working
fluid stream S138 having parameters as at a point 138.
[0052] Referring now to FIG. 2, another preferred embodiment of a
bottoming cycle a fully condensed working solution stream S100
having parameters as at a point 29, corresponding a state of
saturated liquid at ambient temperature, is sent into a feed pump
FP, where it is pumped to a required high pressure to form a
working solution stream S102 having parameters as at a point 100.
In certain CTCSS variants, the feed pump FP may be redundant with
the pump P3 of the CTCSS. The pressure of the stream S102 having
the parameters at the point 100 can be lower or higher than the
critical pressure of the working fluid.
[0053] The stream S102 having the parameters as at the point 100
then enters into an initial heat exchange section or preheater
section HR1 of the HRVG. In the preheater section HR1 of the HRVG,
the stream S102 having the parameters as at the point 100 is heated
in counterflow by a low temperature heat source stream S104 having
parameters as at a point 608, usually a low temperature flue gas
stream, to form a working solution stream S106 having parameters as
at a point 101 and a spent heat source stream S108 having
parameters as at a point 609 in a heat exchange process 100-101 or
608-609. The stream S106 having the parameters as at the point 101
corresponds to a state of subcooled liquid.
[0054] Thereafter the stream S106 of working fluid having the
parameters as at the point 101, enters into a subsequent portion
HR2 of the HRVG, where further heating of the working fluid stream
is provided by the heat source stream and by heat released from the
intercooler as described below.
[0055] In this section HR2 of the HRVG, heat released from the
intercooler is actually heating the heat source gas. This heat is
then transferred from the heat source gas to the working fluid as
described below. The working fluid stream S106 having the
parameters as at the point 101 enters into the section HR2 of the
HRVG is first heated to a state of saturated liquid (or in case of
supercritical pressure, to critical temperature) in a heat exchange
process 101-111 or 610-608 with a heat source stream S110 having
parameters as at a point 610 forming a working fluid stream S112
having parameters as at a point 111 and the stream S104 having the
parameters as at the point 608. Thereafter, the working fluid S112
having the parameters as at the point 111 is either vaporized and
superheated (in cases of subcritical pressure) or is simply
superheated (in cases of supercritical pressure) in a third section
HR3 of the HRVG in a heat exchange process 111-102 or 607-610. In
either case, the stream S112 having the parameters as at the point
111 is heated with a heat source stream S114 having parameters as
at a point 607 to form a working fluid stream S116 having
parameters as at a point 102 and the heat source stream S110 having
parameters as at the point 610.
[0056] Simultaneously, an HPT spent working fluid stream S118
having parameters as at a point 107 enters into the intercooler
portion of the HRVG which comprises the HR2 and HR3 sections of the
HRVG to provide heat to the intercooler process. Upon entering the
HR3 section of the HRVG, the stream S118 having the parameters as
at the point 107 flows in counterflow to the stream S112 having the
parameters as at the point 111 and concurrent flow with the heat
source stream S114 having the parameters as at the 607. Thus, both
the stream S114 and S118 provide heat to the counterflow stream
S112 producing the working fluid stream S116 having the parameters
as at the point 102, a cooled HPT working fluid stream S120 having
parameters as at a point 110 and the heat source stream S110 having
the parameters as at the point 610 in a first intercool heat
exchange process 607-610, 102-111, or 107-110.
[0057] In the second section HR2 of the intercooler section of the
HRVG, the cooled HPT working fluid stream S120 having the
parameters as at the point 110 and the heat source stream S110
having the parameters as at the point 610 provide heat to the
working fluid stream S106 having the parameters as at the point
101. In the intercooler heat exchange processes 610-608, 101-111
and 110-108, the working fluid stream S106 having the parameters as
at the point 101, the cooled HPT working fluid stream S120 having
the parameters as at the point 110 and the heat source stream S110
having the parameters as at the point 610 produce the working fluid
stream S112 having the parameters as at the point 111, an initial
LPT working fluid stream S122 having the parameters as at the point
108 and the heat source stream S104 having the parameters as at the
point 608.
[0058] The total quantity of heat transferred to the working fluid
stream S106 in a combined heat exchange process 101-102 is equal to
a sum of heat released by the heat source in a combined heat
exchange process 607-608, and heat released by the intercooler in
process 107-108.
[0059] Thereafter, the working fluid stream S116 having the
parameters as at the point 102 is further heated in a fourth heat
exchange section HR4 of the HRVG by heat released from a
counterflow heat source stream S124 having parameters as at a point
605 forming a working fluid stream S126 having parameters as at a
point 103 as described below. The working fluid stream S126 having
the parameters as at the point 103 is then yet further heated in a
fifth section HR5 of the HRVG by a counterflow initial heat source
stream S128 having the parameters as at the point 600 forming a
fully vaporized and superheated working fluid stream S130 having
the parameters as at the point 104, corresponding to a state of
superheated vapor.
[0060] The superheated working fluid stream S130 having the
parameters as at the point 104 passes through an admission valve
TV1 to form an HPT addition stream S132 having the parameters as at
the point 109, and enters into a high pressure turbine stage HPT of
a turbine subsystem T. In the HPT, the working fluid stream S132
having the parameters as at the point 109 is expanded to an
intermediate pressure, producing mechanical power and/or electrical
power, to form an HPT spent stream S118 having parameters as at a
point 107.
[0061] In this embodiment, the heat required for vaporization of
the working fluid S102 is supplied primarily by the medium
temperature portions of the heat source stream S124, S10 and S104,
as well as by the heat released in the intercooler by the HPT spent
stream S118 as described above.
[0062] The stream S118 having the parameters as at the point 107,
which is in a state of superheated vapor, is then sent back into
the HRVG (into the intercooler sections HR3 and HR2 of the HRVG),
where it passes through tubes which are parallel to tubes through
which the upcoming high pressure working fluid stream S102 is
flowing. In this manner, streams S118 and S120 having the
parameters as at the points 107 and 101, respectively, passes in
counterflow to the streams S106 and S112 having the parameters as
at the points 101 or 111, respectively, as described above, and
simultaneously, in parallel flow with the heat source streams S114
and S110 having the parameters as at the point 607 and 610,
respectively, as described above.
[0063] The temperature of the working fluid streams S106 and S112
in the intercooler are always higher than the temperature of the
surrounding heat source streams S114 and S110. Therefore, while the
heat source stream is cooled by the upcoming stream of high
pressure working fluid streams S106 and S112, it is simultaneously
heated by the parallel streams S118 and S120 of working fluid in
the intercooler.
[0064] Note that stream S120 having the parameters as at the point
110 in the intercooler and the heat source stream S110 having the
parameters as at the point 610 correspond to the boiling point of
the stream S112 having the parameters as at the point 111 (or to
the critical point, in the case of supercritical pressure) of the
upcoming stream S106 of high pressure working fluid having the
parameters as at the point 101.
[0065] Meanwhile, the working fluid stream S122 having the
parameters as at the point 108, corresponding to a state of
superheated vapor, and is sent into a low pressure turbine stage
LPT of the turbine T, where it is fully expanded, producing
mechanical power and/or electrical power, forming a spent working
fluid stream S138 having parameters as at a point 138.
[0066] The stream S138 having the parameters as at the point 138
may then be sent directly to a condenser, or in an alternate
embodiment of the proposed system, may be sent into a condensation
thermal compression subsystem (CTCSS).
CTCSS Variant 1a
[0067] Referring now to FIG. 3, a preferred embodiment of a CTCSS
of this invention, generally 136, is shown and is referred to
herein as Variant 1a. Variant 1a represents a very comprehensive
variant of the CTCSSs of this invention.
[0068] The operation of Variant 1a of the CTCSS of this invention
is now described.
[0069] The spent stream S138 having parameters as at a point 138,
which can be in a state of superheated vapor or in a state of
saturated or slightly wet vapor, enters into the CTCSS. The stream
S138 having the parameters as at the point 138 is mixed with a
first mixed stream S202 having parameters as at a point 71, which
is in a state of a liquid-vapor mixture (as describe more fully
herein), forming a first combined stream S204 having parameters as
at apoint38. If the stream S138 having the parameters as at the
point 138 is in a state of saturated vapor, then a temperature of
the stream S202 having the parameters as at the point 71 must be
chosen in such a way as to correspond to a state of saturated
vapor. As a result, the stream S204 having the parameters as at the
point 38 will be in a state of a slightly wet vapor. Alternatively,
if the stream S138 having the parameters as at the point 138 is in
a state of superheated vapor, then stream S202 having the
parameters of at the point 71 must be chosen in such a way that the
resulting stream S204 having the parameters as at a point 38 should
be in, or close to, a state of saturated vapor, where close to
means the state of the vapor is within 5% of the saturated vapor
state for the vapor. In all cases, the parameters of the stream
S202 at the point 71 are chosen in such a way as to maximize a
temperature of the stream S204 at the point 38.
[0070] Thereafter, the stream S204 having the parameters as at the
point 38 passes through a first heat exchanger HE1, where it is
cooled and partially condensed and releases heat in a first heat
exchange process, producing a second mixed stream S206 having
parameters as at a point 15. The stream S206 having the parameters
as at the point 15 is then mixed with a stream S208 having
parameters as at a point 8, forming a stream S210 having parameters
as at a point 16. In the preferred embodiment of this system, the
temperatures of the streams S208, S206 and S210 having parameters
of the points 8, 15, and 16, respectively, are equal or very close,
within about 5%. A concentration of the low-boiling component in
stream S208 having the parameters as at the point 8 is
substantially lower than a concentration of the low boiling
component in the stream S206 having the parameters as at the point
15. As a result, a concentration of the low boiling component in
the stream S210 having the parameters as at the point 16 is lower
than the concentration of the low boiling component of the stream
S206 having the parameters as at the point 15, i.e., stream S210
having the parameters as at the point 16 is leaner than stream S206
having the parameters as at the point 15.
[0071] The stream S210 having the parameters as at the point 16
then passes through a second heat exchanger HE2, where it is
further condensed and releasing heat in a second heat exchange
process, forming a stream S212 having parameters as at a point 17.
The stream S212 having the parameters as at the point 17 then
passes through a third heat exchanger HE3, where it is further
condensed in a third heat exchange process to form a stream S214
having parameters as at a point 18. At the point 18, the stream
S214 is partially condensed, but its composition, while
substantially leaner that the compositions of the stream S138 and
S204 having the parameters as at the points 138 and 38, is such
that it cannot be fully condensed at ambient temperature. The
stream S214 having the parameters as at the point 18 is then mixed
with a stream S216 having parameters as at a point 41, forming a
stream S218 having parameters as at a point 19. The composition of
the stream S218 having the parameters as at the point 19 is such
that it can be fully condensed at ambient temperature.
[0072] The stream S218 having the parameters as at the point 19
then passes through a low pressure condenser HE4, where it is
cooled in a fourth heat exchange process in counterflow with a
stream S220 of cooling water or cooling air having initial
parameters as at a point 51 and final parameters as at a point 52,
becoming fully condensed, to form a stream S222 having parameters
as at a point 1. The composition of the stream S222 having the
parameters as at the point 1, referred to herein as the "basic
solution," is substantially leaner than the composition of the
stream S138 having the parameters at the point 138, which entered
the CTCSS. Therefore, the stream S222 having the parameters as at
the point 1 must be distilled at an elevated pressure in order to
produce a stream having the same composition as at point 138, but
at an elevated pressure that will allow the stream to fully
condense.
[0073] The stream S222 having the parameters as at the point 1 is
then divided into two substreams S224 and S226 having parameters as
at points 2 and 4, respectively. The stream S224 having the
parameters as at the point 2 enters into a circulating fourth pump
P4, where it is pumped to an elevated pressure forming a stream
S228 having parameters as at a point 44, which correspond to a
state of subcooled liquid. Thereafter, the stream S228 having the
parameters as at the point 44 passes through a third heat exchanger
HE3 in counterflow with the stream S212 having the parameters as at
the point 17 in a third heat exchange process as described above,
is heated forming a stream S230 having parameters as at a point 14.
The stream S230 having the parameters as at the point 14 is in, or
close to, a state of saturated liquid. Again, the term close to
means that the state of the stream S230 is within 5% of being a
saturated liquid. Thereafter, the stream S230 having parameters as
at point 14 is divided into two substreams S232 and S234 having
parameters as at points 13 and 22, respectively. The stream S234
having the parameters as at the point 22 is then divided into two
substreams S236 and S238 having parameters as at points 12 and 21,
respectively. The stream S236 having the parameters as at the point
12 then passes through the second heat exchanger HE2, where it is
heated and partially vaporized in counterflow to the stream S210
having the parameters as at the point 16 as described above in a
second heat exchange process, forming a stream S240 having
parameters as at a point 11. The stream S240 having the parameters
as at the point 11 then passes through the first heat exchanger
HE1, where it is further heated and vaporized in counterflow to the
stream S204 having stream 38 as described above in a first heat
exchange process, forming a stream S242 having parameters as at a
point 5.
[0074] The stream S242 having the parameters as at the point 5,
which is in a state of a vapor-liquid mixture, enters into a first
separator S1, where it is separated into a saturated vapor stream
S244 having parameters as at a point 6 and saturated liquid stream
S246 having parameters as at a point 7.
[0075] The liquid stream S246 having the parameters as at the point
7 is divided into two substreams S248 and S250 having parameters as
at points 70 and 72, respectively. The stream S248 having the
parameters as at the point 70, then passes through an eighth heat
exchanger HE8, where it is heated and partially vaporized in an
eighth heat exchange process, in counterflow to an external heat
carrier stream S252 having initial parameters as a point 638 and
final parameters as at a pint 639, forming a stream S254 having
parameters as at a point 74. Thereafter, stream S254 having the
parameters as at the point 74 passes through a fifth throttle valve
TV5, where its pressure is reduced to a pressure equal to a
pressure of the stream S138 having the parameters as at the point
138, forming the stream S202 having the parameters as at the point
71. Thereafter, the stream S202 having the parameters as at the
point 71 is mixed with the stream S138 having the parameters as at
the point 138, forming the stream S204 having the parameters as at
the point 38 as previously described.
[0076] The stream S250 having parameters as at point 72, then
passes through a first throttle valve TV1, where its pressure is
reduced, forming a stream S256 having parameters as at a point 73.
The pressure of the stream S256 having the parameters as at the
point 73 is equal to a pressure of the streams S206, S208, and S210
having the parameters as at the points 15, 8 and 16. Thereafter the
stream S256 having the parameters as at the point 73 is mixed with
a stream S258 having parameters as at a point 45, forming the
stream S208 having the parameters as at the point 8. The stream
S208 having the parameters as a the point 8 is then mixed with the
stream S206 having the parameters as at the point 15, forming the
stream S210 having the parameters as at the point 16 as described
above.
[0077] Meanwhile, the vapor stream S244 having the parameters as at
the point 6 is sent into a bottom part of a first scrubber SC1,
which is in essence a direct contact heat and mass exchanger. At
the same time, the stream S238 having the parameters as at the
point 21 as described above, is sent into a top portion of the
first scrubber SC1. As a result of heat and mass transfer in the
first scrubber SC1, a liquid stream S260 having parameters as at a
point 35, which is in a state close to equilibrium (close means
within about 5% of the parameters of the stream S244) with the
vapor stream S244 having the parameters as at the point 6, is
produced and removed from a bottom of the first scrubber SC1. At
the same time, a vapor stream S262 having parameters as at point
30, which is in a state close to equilibrium with the liquid stream
S238 having the parameters as at the point 21, exits from a top of
the scrubber SC1.
[0078] The vapor stream S262 having the parameters as at the point
30 is then sent into a fifth heat exchanger HE5, where it is cooled
and partially condensed, in counterflow with a stream S264 of
working fluid having parameters as at a point 28 in a fifth heat
exchange process, forming a stream S266 having parameters as at a
point 25.
[0079] The liquid stream S260 having the parameters as at the point
35 is removed from the bottom of the scrubber SC1 and is sent
through a fourth throttle valve TV4, where its pressure is reduced
to a pressure equal to the pressure of the stream S256 having the
parameters as at the point 73, forming the stream S258 having the
parameters as at the point 45. The stream S258 having the
parameters as at the point 45 is then mixed with the stream S256
having the parameters as at the point 73, forming the stream S208
having the parameters as at the point 8 as described above.
[0080] The liquid stream S232 having the parameters as at the point
13, which has been preheated in the third heat exchanger HE3 as
described above, passes through a second throttle valve TV2, where
its pressure is reduced to an intermediate pressure, (i.e., a
pressure which is lower than the pressure of the stream S230 having
the parameter as at the point 14, but higher than the pressure of
the stream S222 having the parameters as at the point 1), forming a
stream S268 parameters as at a point 43, corresponding to a state
of a vapor-liquid mixture. Thereafter, the stream S268 having the
parameters as at the point 43 is sent into a third separator S3,
where it is separated into a vapor stream S270 having parameters as
at a point 34 and a liquid stream S272 having parameters as at a
point 32.
[0081] A concentration of the low boiling component in the vapor
stream S270 having the parameters as at the point 34 is
substantially higher than a concentration of the low boiling
component in the stream S138 having the parameters as at the point
138 as it enters the CTCSS as described above. The liquid stream
S272 having the parameters as at the point 32 has a concentration
of low boiling component which is less than a concentration of low
boiling component in the stream S222 having the parameters as at
the point 1 as described above.
[0082] The liquid stream S226 of the basic solution having the
parameters as at the point 4 as described above, enters into a
first circulating pump P1, where it is pumped to a pressure equal
to the pressure of the stream S270 having the parameters as at the
point 34, forming a stream S274 having parameters as at a point 31
corresponding to a state of subcooled liquid. Thereafter, the
subcooled liquid stream S274 having the parameters as at the point
31 and the saturated vapor stream S270 having the parameters as at
the point 34 are combined, forming a stream S276 having parameters
as at a point 3. The stream S276 having the parameters as at the
point 3 is then sent into an intermediate pressure condenser or a
seventh heat exchanger HE7, where it is cooled and fully condensed
in a seventh heat exchange process, in counterflow with a stream
S278 of cooling water or air having initial parameters as at a
point 55 and having final parameters as at a point 56, forming a
stream S280 having parameters as at a point 23. The stream S280
having parameters as at point 23 then enters into a second
circulating pump P2, where its pressure is increased to a pressure
equal to that of the stream S266 having the parameters as at the
point 25 as described above, forming a stream S282 parameters as at
a point 40. The stream S282 having the parameters as at the point
40 is then mixed with the stream S266 having the parameters as at
the point 25 as described above, forming a stream S284 having
parameters as at a point 26. The composition and flow rate of the
stream S282 having the parameters as at the point 40 are such that
the stream S284 having the parameters as at the point 26 has the
same composition and flow rate as the stream S138 having the
parameters as at the point 138, which entered the CTCSS, but has a
substantially higher pressure.
[0083] Thereafter, the stream S284 having the parameters as at the
point 26 enters into a high pressure condenser or sixth heat
exchanger HE6, where it is cooled and fully condensed in a sixth
heat exchange process, in counterflow with a stream S286 of cooling
water or air having initial parameters as at a point 53 and final
parameters as at a point 54, forming a steam S288 parameters as at
a point 27, corresponding to a state of saturated liquid. The
stream S288 having the parameters as at the point 27 then enters
into a third or feed pump P3, where it is pumped to a desired high
pressure, forming the stream S264 having the parameters as at the
point 28. Then the stream S264 of working fluid having the
parameters as at the point 28 is sent through the fifth heat
exchanger HE5, where it is heated, in counterflow with the stream
S262 having the parameters as at the point 30 in the fifth heat
exchange process, forming a stream S290 having parameters as at a
point 29 as described above. The stream S290 having the parameters
as at a point 29 then exits the CTCSS, and returns to the power
system. This CTCSS of this invention is closed in that no material
is added to any stream in the CTCSS.
[0084] In some cases, preheating of the working fluid which is
reproduced in the CTCSS is not necessary. In such cases, the fifth
heat exchanger HE5 is excluded from the Variant 1a described above.
As a result, the stream S262 having the parameters as at the point
30 and the stream S266 having the parameters as at the point 25 are
the same, and the stream S264 having the parameters at the point 28
are the stream S290 having the parameters as at the point 29 are
the same as shown in FIG. 4. The CTCSS system in which HE5 is
excluded is referred to as Variant 1b.
[0085] The CTCSSs of this invention provide highly effective
utilization of heat available from the condensing stream S138 of
the working solution having the parameters as at the point 138 and
of heat from external sources such as from the stream S252.
[0086] In distinction from an analogous system described in the
prior art, the lean liquid stream S246 having the parameters as at
the point 7 coming from the first separator S1, is not cooled in a
separate heat exchanger, but rather a portion of the stream S246 is
injected into the stream S138 of working fluid returning from the
power system.
[0087] When the stream S236 of basic solution having the parameters
as at the point 12 starts to boil, it initially requires a
substantial quantity of heat, while at the same time its rise in
temperature is relatively slow. This portion of the reboiling
process occurs in the second heat exchanger HE2. In the process of
further reboiling, the rate of increase in the temperatures becomes
much faster. This further portion of the reboiling process occurs
in the first heat exchanger HE1. At the same time, in the process
of condensation of the stream S204 having the parameters as at the
point 38, initially a relatively large quantity of heat is
released, with a relatively slow reduction of temperature. But in
further condensation, the rate of reduction of temperature is much
higher. As a result of this phenomenon, in the prior art, the
temperature differences between the condensing stream of working
solution and the reboiling stream of basic solution are minimal at
the beginning and end of the process, but are quite large in the
middle of the process.
[0088] In contrast to the prior art, in the CTCSS of this
invention, the concentration of the low boiling component in stream
S208 having the parameters as at the point 8 is relatively low and
therefore in the second heat exchanger HE2, stream S208 having the
parameters as at the point 8 not only condenses itself, but has the
ability to absorb additional vapor. As a result, the quantity of
heat released in the second heat exchanger HE2 in the second heat
exchange process is substantially larger than it would be if
streams S208 and S206 having the parameters as at the points 8 and
15, respectively, were cooled separately and not collectively
collect after combining the two stream S208 and S206 to form the
stream S210. As a result, the quantity of heat available for the
reboiling process comprising the first and second heat exchange
processes is substantially increased, which in turn increases the
efficiency of the CTCSS system.
[0089] The leaner the stream S208 having the parameters at as the
point 8 is, the greater its ability to absorb vapor, and the
greater the efficiency of the heat exchange processes occurring in
the first and second heat exchangers HE1 and HE2. But the
composition of the stream S208 having the parameters at as the
point 8 is defined by the temperature of the stream S242 having the
parameters as at the point 5; the higher the temperature of the
stream S242 having the parameters as at the point 5, the leaner the
composition of stream S208 having the parameters at as the point 8
can be.
[0090] It is for this reason that external heat derived from stream
S252 is used to heat stream S248 having the parameters as at the
point 70, thus raising the temperature of the stream S204 having
the parameters as at the point 38, and as a result also raising the
temperature of the stream S242 having the parameters as at the
point 5. However, increasing of the temperature of the stream S242
having the parameters as at the point 5, and correspondingly the
temperature of the stream S244 having the parameters as at a point
6, leads to a reduction in a concentration of the low boiling
component in the vapor stream S244 having the parameters as at the
point 6.
[0091] Use of the scrubber SC1, in place of a heat exchanger, for
the utilization of heat from the stream S244 having the parameters
as at the point 6 allows both the utilization of the heat from the
stream S244 having the parameters as at the point 6 and an increase
of the concentration of low boiling component in the produced vapor
stream S262 having the parameters as at the point 30.
[0092] The vapor stream S262 having the parameters as at the point
30 has a concentration of low-boiling component which is higher
than the concentration of the low boiling component in the vapor
stream S244 having the parameters as at the point 6, and the flow
rate of stream S262 having the parameters as at the point 30 is
higher than the flow rate of the stream S244 having the parameters
as at the point 6.
[0093] The concentration of low boiling component in the working
fluid is restored in the stream S284 having the parameters at the
point 26, by mixing the stream S266, a very rich solution, having
the parameters as at the point 25 (or the stream S262 having the
parameters as at the point 30, in the case of the Variant 1b), with
the stream S282 having the parameters as at the point 40. The
stream S282 having the parameters as at point 40 has a higher
concentration of low boiling component than the basic solution,
(i.e., is enriched). Such an enrichment has been used in the prior
art, but in the prior art, in order to obtain this enrichment, a
special intermediate pressure reboiling process is needed requiring
several additional heat exchangers.
[0094] In the CTCSSs of this invention, all heat that is available
at a temperature below the boiling point of the basic solution
(i.e., below the temperature of the stream S230 having the
parameters as at the point 14) is utilized in a single heat
exchanger, the third heat exchanger HE3. Thereafter, the vapor
needed to produce the enriched stream S282 having the parameters as
at the point 40 is obtained simply by throttling the stream S232
having the parameters as at the point 13.
[0095] In U.S. Pat. No. 5,572,871, a DCSS (CTCSS) required 13 heat
exchangers and three separators, and did not provide for the
potential utilization of external heat. In contrast, the CTCSS of
the present invention, which does provide for the utilization of
external heat, requires only eight heat exchangers, two separators
and one scrubber (which is substantially simpler and less expensive
than a heat exchanger.)
[0096] A table of example parameters of all points for variant 1b
is presented in Table 1. TABLE-US-00001 TABLE 1 CTCSS State Points
Summary (Variant 1b) Wetness X T P H S G rel (lb/lb/) or Point
(lb/lb) (.degree. F.) (psia) (Btu/lb) (Btu/lb-R) (G/G = 1) Phase T
(.degree. F.) Working Fluid 01 0.4640 65.80 30.772 -72.3586 0.0148
8.39248 Mix 1 02 0.4640 65.97 73.080 -72.0625 0.0151 8.39248 Liq
-45.53.degree. F. 03 0.6635 103.77 73.080 180.1339 0.4592 0.49176
Mix 0.6584 04 0.4640 65.97 73.080 -72.0625 0.0151 8.08657 Liq
-45.53.degree. F. 05 0.4640 191.03 100.823 234.3143 0.5229 1.83999
Mix 0.7351 06 0.9337 191.03 100.823 662.3343 1.2517 0.48733 Mix 0
07 0.2948 191.03 100.823 80.1075 0.2603 1.35266 Mix 1 08 0.2948
143.93 34.772 80.1074 0.2651 1.34681 Mix 0.93 11 0.4640 137.27
102.823 24.6957 0.1857 1.83999 Mix 0.9707 12 0.4640 133.62 104.823
2.9022 0.1490 1.83999 Mix 1 13 0.4640 133.62 104.823 2.9022 0.1490
5.99531 Mix 1 14 0.4640 133.62 104.823 2.9022 0.1490 8.08657 Mix 1
15 0.7277 143.93 34.772 463.0612 0.9967 1.23621 Mix 0.2994 16
0.5020 143.93 34.772 263.3857 0.6153 2.58302 Mix 0.6282 17 0.5020
138.62 33.772 247.8614 0.5906 2.58302 Mix 0.6417 18 0.5020 76.28
32.772 13.9449 0.1776 2.58302 Mix 0.8841 19 0.4640 80.93 32.772
-6.8178 0.1376 8.39248 Mix 0.9257 21 0.4640 131.71 100.823 2.9022
0.1490 0.25126 Mix 0.9964 22 0.4640 133.62 104.823 2.9022 0.1490
2.09125 Mix 1 23 0.6635 65.80 71.080 -56.4301 0.0224 0.49176 Mix 1
24 0.9337 191.03 100.823 662.3343 1.2517 0.48733 Mix 0 25 0.9911
131.71 100.823 600.2216 1.1578 0.50824 Mix 0 26 0.8300 87.68
100.823 277.4277 0.6017 1.00000 Mix 0.4842 27 0.8300 65.80 98.823
-17.0503 0.0497 1.00000 Mix 1 28 0.8300 70.73 1,900.000 -7.8325
0.0525 1.00000 Liq -256.82.degree. F. 29 0.8300 70.73 1,900.000
-7.8325 0.0525 1.00000 Liq -256.82.degree. F. 30 0.9911 131.71
100.823 600.2216 1.1578 0.50824 Mix 0 31 0.4640 65.97 73.080
-72.0625 0.0151 0.30591 Liq -45.53.degree. F. 32 0.4471 116.52
73.080 -16.0494 0.1167 5.80941 Mix 1 34 0.9919 116.52 73.080
595.1359 1.1849 0.18590 Mix 0 35 0.2948 191.03 100.823 80.1075
0.2603 0.23036 Mix 1 38 0.7277 196.03 35.772 775.0604 1.4862
1.23621 Vap 0.degree. F. 40 0.6635 65.96 100.823 -56.1779 0.0227
0.49176 Liq -19.53.degree. F. 41 0.4471 82.91 32.772 -16.0494
0.1196 5.80941 Mix 0.9442 43 0.4640 116.52 73.080 2.9022 0.1498
5.99531 Mix 0.969 44 0.4640 66.12 109.823 -71.8156 0.0153 8.08657
Liq -70.52.degree. F. 45 0.2948 143.93 34.772 80.1075 0.2651
0.23036 Mix 0.93 70 0.2948 191.03 100.823 80.1075 0.2603 0.23621
Mix 1 71 0.2948 227.10 35.772 615.2057 1.0815 0.23621 Mix 0.4122 72
0.2948 191.03 100.823 80.1075 0.2603 1.11645 Mix 1 73 0.2948 143.93
34.772 80.1075 0.2651 1.11645 Mix 0.93 74 0.2948 284.54 98.823
615.2060 1.0182 0.23621 Mix 0.4545 138 0.8300 358.47 35.772
812.8197 1.5611 1.00000 Vap 181.2.degree. F. External Heat Source
638 AIR 351.74 12.976 99.4176 0.5970 3.83489 Vap 666.2.degree. F.
639 AIR 216.03 12.904 66.4582 0.5529 3.83489 Vap 530.5.degree. F.
Coolant 51 water 51.80 24.693 19.9498 0.0396 27.3421 Liq
-187.56.degree. F. 52 water 71.93 14.693 40.0672 0.0783 27.3421 Liq
-140.03.degree. F. 53 water 51.80 24.693 19.9498 0.0396 13.6854 Liq
-187.56.degree. F. 54 water 73.33 14.693 41.4676 0.0809 13.6854 Liq
-138.63.degree. F. 55 water 51.80 24.693 19.9498 0.0396 3.07700 Liq
-187.56 F. 56 water 89.63 14.693 57.7573 0.1110 3.07700 Liq
-122.32.degree. F.
[0097] The CTCSSs of this invention can be simplified by
eliminating some "modular" components. For instance, it is possible
to enrich the stream S282 having the parameters as at the point 40
without using the intermediate pressure condenser, the seventh heat
exchanger HE7. Such a system, with preheating of the stream S264 of
working fluid having the parameters as at the point 28 is shown in
FIG. 3, and referred to as Variant 2a. A similar system, but
without preheating the stream S264 of working fluid having the
parameters as at the point 28, is shown in FIG. 4, and referred to
as Variant 2b.
[0098] In the Variant 2a and Variant 2b, in distinction to the
Variant 1a and Variant 1b, the pressure of the stream S268 having
the parameters as at the point 43 is chosen in such a way that the
when mixing the vapor stream S270 having the parameters as at the
point 34 and the liquid stream S274 having the parameters as at the
point 31, the subcooled liquid stream S274 having the parameters as
at the point 31 fully absorbs the vapor stream S270 having the
parameters as at the point 34, and the resulting stream S276 having
the parameters as at the point 3 is in a state of saturated, or
slightly subcooled, liquid. Thereafter, the liquid S276 having the
parameters as at the point 3 is sent into the second pump P2, to
form the stream S282 having the parameters as at the point 40, and
is mixed with stream 25.
[0099] The simplification of the CTCSS of Variant 2a and Variant 2b
reduces the overall efficiency of the CTCSSs of this invention, but
at the same time, the cost is also reduced.
[0100] Another possible modular simplification of the Variant 1a
and Variant 1b can be used in a case where external heat is not
available, or the choice is made not to utilize external heat. Such
a variant of the CTCSS of this invention, with preheating of the
stream S264 of working fluid having the parameters as at the point
28 is shown in FIG. 5, and is referred to as Variant 3a. A similar
CTCSS of this invention, but without preheating the stream S264 of
the working fluid having the parameters as at the point 28, is
shown in FIG. 6, and referred to as Variant 3b.
[0101] In Variant 3a and Variant 3b, the stream S248 having the
parameters as at the point 70 is not heated, but rather simply
passes through the fifth throttle valve TV5, to form the stream
S202 having the parameters as at the point 71, and is then mixed
with the stream S138 having the parameters as at the point 138,
forming the stream S204 having the parameters as at the point 38.
This mixing process is used only in a case where the stream S138
having the parameters as at the point 138 is in a state of
superheated vapor. The flow rate of streams S248 and S202 having
the parameters as at the points 70 and 71 is chosen in such a way
that the stream S204 having the parameters as at the point 38
formed as a result of mixing the stream S202 having the parameters
as at the point 71 and the stream S138 having the parameters as at
the point 138 is in a state of saturated, or slightly wet,
vapor.
[0102] It is also possible to simplify Variant 2a and Variant 2b in
the same manner than Variant 1a and Variant 1b are simplified to
obtain Variant 3a and Variant 3b. This modular simplification of
Variant 2a and Variant 2b, with preheating of the stream S264 of
the working fluid having the parameters as at the point 28 is shown
in FIG. 7, and is referred to as Variant 4a; while a similar
simplification of Variant 2b, without preheating the stream S264 of
the working fluid having the parameters as at the point 28, is
shown in FIG. 8, and referred to as Variant 4b.
[0103] A final modular simplification is attained by eliminating
the scrubber SC1, and the use of the stream S282 having the
parameters as at the point 40 without any enrichment, i.e., the
composition of stream S282 having the parameters as at the point 40
is the same as the composition of the basic solution. This modular
simplification of Variant 4a, with preheating of the stream S264 of
the working fluid having the parameters as at the point 28 is shown
in FIG. 9, and is referred to as Variant 5a. A similar
simplification of Variant 4b, without preheating the stream S264 of
the working fluid having the parameters as at the point 28, is
shown in FIG. 10, and referred to as Variant 5b. It must be noted
that the modular simplification of the Variant 5a and Variant 5b
results in a substantial reduction of the efficiency of the CTCSS.
Also in Variants 5a and 5b, the stream S222 having the parameters
as at the point 1 is not split into two substreams S222 and S224
which are then separately pressurized, but is pressurized in as a
single stream in a pump P5 forming a stream S292 having parameters
as at a point 46. The stream S292 is then split to form the stream
S228 having the parameters as at the point 44 and the stream S282
having the parameters as at the point 40.
[0104] The CTCSSs of this invention is described in the five basic
variants given above; (two of which utilize external heat, and
three of which utilize only the heat available from the stream S200
of the working fluid entering the CTCSSs of this invention). One
experienced in the art would be able to generate additional
combinations and variants of the proposed systems. For instance, it
is possible to simplify Variant 4a by eliminating the scrubber SC1,
while retaining the enrichment of the stream S282 having the
parameters as at the points 40. (Likewise it is possible to retain
the scrubber SC1, and eliminate only the enrichment process for the
stream S282 having the parameters as at the points 40.) However all
such modular simplifications are still based on the initial Variant
1a of the CTCSSs of this invention.
[0105] The efficacy of the CTCSS of this invention, per se, can be
assessed by its compression ratio; i.e., a ratio of the pressure of
the stream S284 having the parameters as at the point 26 (at the
entrance to the high pressure condenser, heat exchanger HE6) to the
pressure of the stream S138 having the parameters as at the point
138 (at the point of entrance of the stream of working solution
into the CTCSS). The impact of the efficacy of the CTCSS on the
efficiency of the whole system depends on the structure and
parameters of work of the whole system. For assessing the CTCSSs of
this invention, several calculations have been performed. A stream
comprising a water-ammonia mixture having a composition of 0.83
weight fraction of ammonia (i.e., 83 wt. % ammonia), with an
initial temperature of 1050.degree. F. and an initial pressure of
1800 psia, has been expanded in a turbine with an isoenthropic
efficiency of 0.875 (87.5%). The parameters of the vapor upon
exiting the turbine correspond to the stream S138 having the
parameters at the point 138. Such computations have been performed
for all proposed "b" variants of the CTCSS of this invention
described above, and for a simple condenser system as well. These
calculations are presented in Table 2. It should be noted that the
incremental enthalpy drop produced by using a CTCSS of this
invention is specific to the exact parameters of pressure and
temperature at the turbine inlet. If these parameters were to be
lowered, then the percentage of increase in enthalpy drop would be
substantially larger. TABLE-US-00002 TABLE 2 Efficacy of CTCSS
Variants 1b, 2b, 3b, 4b, and 5b Simple CTCSS CTCSS CTCSS CTCSS
CTCSS Condenser Variant 1b Variant 2b Variant 3b Variant 4b Variant
5b pressure of 100.823 35.771 38.972 42.067 45.079 59.368 turbine
outlet (point 138) (psia) compression 1.000 2.8181 2.5871 2.3967
2.2366 1.69827 ratio (P26:P138) turbine 337.3891 418.6930 412.5639
407.0011 410.8869 380.7543 enthalpy drop (btu/lb) incremental 0.000
81.3040 75.1748 69.6119 64.4978 43.3652 enthalpy drop (btu/lb)
incremental 0.000 24.098 22.281 20.633 19.117 12.853 enthalpy drop
(%)
[0106] Comparison has shown that all variants of the CTCSSs of this
invention have an efficacy that is higher or equal to comparable
subsystems in the prior art. However, all of the proposed CTCSS are
substantially simpler and less expensive than the subsystems
described in the prior art.
[0107] The proposed system has all the advantages of systems given
in the prior art, but is much simpler and does not require an
expensive separate intercooler. Moreover, the loss of pressure in
the process of intercooling is smaller because there is no entrance
and exit pressure losses into or out of a special separate
intercooler heat exchanger.
[0108] Due to the fact that the working fluid in the intercooler
portion of the HRVG transfers its heat to the flue gas, as opposed
to directly transferring the heat to the upcoming stream of working
fluid, the temperature difference in between the working fluid
flowing through the intercooler and the upcoming stream of high
pressure working fluid is larger than the analagous temperature
difference in the prior art. As a result the proposed system has a
slightly lower thermal efficiency that the system described in the
prior art. Detailed calculations have shown that the proposed
system has an efficiency which is 0.85% lower than the system
described in the prior art.
[0109] However, the proposed system allows for the cooling of flue
gas to a lower temperature than is possible in the system described
in the prior art, and therefore the proposed system is able to
utilize more heat for a given heat source stream. As a result, the
total output of the proposed system when used as a bottoming cycle
in a combined cycle is 1.6% higher than the total outpuy of the
system described in the prior art used in the same manner. Thus the
overall efficiency of a combined cycle system is increased by 0.64%
as compared to the overall combined cycle efficiency using the
system described in the prior art.
[0110] The proposed system uses a CTCSS (compression thermal
condensation subsystem) which is substantialy simpler and therefore
less expensive than the DCSS (distilation condensation subsystem)
used in the prior art.
[0111] This, together with the elimination of the requirement of a
separate apparatus for intercooling, makes the proposed system
significantly less expensive and at the same time slightly
increasing the overall efficiency of a combined cycle using the
proposed system as compared to the system described in the prior
art.
[0112] The proposed system can be simplified by the exclusion of
process of reheating. Such a system is presented in FIG. 2. It does
not require a separate description. The efficiency of such a
simplified system is lower than the efficiency of the system shown
in FIG. 1, but it is still higher than the efficiency of a double
pressure or triple pressure Rankine cycle that is commonly used as
the bottoming cycle for combined cycle power systems.
[0113] A summary of performance, and parameters at all key points
for the proposed system are presented in Tables 3 and 4 (below.)
TABLE-US-00003 TABLE 3 System Performance Summary Heat in
412,140.52 kW 1,228.46 Btu/lb Heat rejected 248,089.38 kW 739.47
Btu/lb Turbine enthalpy Drops 169,917.96 kW 506.47 Btu/lb Gross
Generator Power 166,995.38 kW 497.76 Btu/lb Process Pumps (-17.49)
-6,233.33 kW -18.58 Btu/lb Cycle Output 160,762.04 kW 479.18 Btu/lb
Other Pumps and Fans (-5.27) -1,878.22 Kw -5.60 Btu/lb Net Output
158,883.82 kW 473.58 Btu/lb Gross Generator Power 166,995.38 kW
497.76 Btu/lb Cycle Output 160,762.04 Kw 479.18 Btu/lb Net Output
158,883.82 kW 473.58 Btu/lb Net thermal efficiency 38.55% % Second
Law Limit 48.78% % Second Law Efficiency 79.03% % Overall Heat
Balance (Btu/lb) Heat In: Source + pumps = 1,228.46 + 17.49 =
1,245.95 Heat Out: Turbines + condenser = 506.47 + 739.47 =
1,245.95
[0114] TABLE-US-00004 TABLE 4 System Point Summary X T P H S Ex G
rel G abs Ph. Pt. lb/lb .degree. F. psia Btu/lb Btu/lb-R Btu/lb G/G
= 1 lb/h lb/lb Wetness Working Fluid 1 0.5132 60.79 36.056 -77.7760
0.0029 0.4290 6.78958 7,777,604 Mix 1 2 0.5132 60.79 36.056
-77.7760 0.0029 0.4290 6.40563 7,337,775 Mix 1 3 0.6603 86.48
64.861 123.4582 0.3613 16.4296 0.55211 632,455 Mix 0.725 4 0.5132
60.79 36.056 -77.7760 0.0029 0.4290 0.38396 439,828 Mix 1 5 0.5132
180.60 89.976 261.0451 0.5755 42.2910 1.28756 1,474,928 Mix 0.6698
6 0.9425 180.60 89.976 653.4035 1.2520 85.7031 0.42514 487,001 Mix
0 7 0.3015 180.60 89.976 67.6314 0.2420 20.8909 0.86243 987,928 Mix
1 8 0.3055 141.58 38.306 65.4145 0.2423 18.5469 1.03795 1,188,995
Mix 0.9433 11 0.5132 136.58 92.976 96.2128 0.3076 16.3960 1.28756
1,474,928 Mix 0.8509 12 0.5132 114.11 95.976 -18.1700 0.1116 3.7026
1.28756 1,474,928 Mix 1 13 0.5132 114.11 95.976 -18.1700 0.1116
3.7026 4.91979 5,635,716 Mix 1 14 0.5132 114.11 95.976 -18.1700
0.1116 3.7026 6.40563 7,337,775 Mix 1 15 0.8100 141.58 38.306
515.8753 1.0937 29.6738 1.00000 1,145,520 Mix 0.1999 16 0.5530
141.58 38.306 286.4505 0.6601 24.0067 2.03795 2,334,514 Mix 0.5786
17 0.5530 119.73 37.556 214.1843 0.5385 14.7790 2.03795 2,334,514
Mix 0.6476 18 0.5530 71.24 36.806 27.9646 0.2025 2.8471 2.03795
2,334,514 Mix 0.8523 19 0.5132 71.58 36.806 -19.1982 0.1143 1.2574
6.78958 7,777,604 Mix 0.9265 21 0.5132 110.55 89.226 -18.1700
0.1116 3.6656 0.19828 227,131 Mix 0.9932 22 0.5132 114.11 95.976
-18.1700 0.1116 3.7026 1.48584 1,702,059 Mix 1 23 0.6603 60.79
64.111 -62.6517 0.0113 11.8994 0.55211 632,455 Mix 1 24 0.9425
180.60 89.976 653.4035 1.2520 85.7031 0.42514 487,001 Mix 0 25
0.9945 67.70 88.476 547.2777 1.0771 70.5188 0.44789 513,065 Mix
0.02 26 0.8100 76.25 88.476 210.6374 0.4891 38.0153 1.00000
1,145,520 Mix 0.5832 27 0.8100 60.79 87.726 -28.3647 0.0351 34.4690
1.00000 1,145,520 Mix 1 28 0.8100 62.70 801.242 -24.7263 0.0363
37.4862 1.00000 1,145,520 Liq -162.95.degree. F. 29 0.8100 79.91
796.242 -5.2335 0.0731 37.9159 1.00000 1,145,520 Liq -145.1.degree.
F. 30 0.9945 115.55 89.226 590.7993 1.1552 73.5436 0.44789 513,065
Mix 0 31 0.5132 60.91 64.861 -77.5683 0.0031 0.5328 0.38396 439,828
Liq -30.32.degree. F. 32 0.4961 95.69 64.861 -39.4261 0.0749 1.3864
4.75163 5,443,089 Mix 1 34 0.9962 95.69 64.861 582.4652 1.1758
54.4994 0.16816 192,627 Mix 0 35 0.3248 171.60 89.976 54.5222
0.2246 16.9105 0.17552 201,067 Mix 1 38 0.8100 185.60 39.056
728.1070 1.4307 67.1204 1.00000 1,145,520 Mix 0 40 0.6603 60.92
88.476 -62.4543 0.0115 11.9938 0.55211 632,455 Liq -17.52.degree.
F. 41 0.4961 71.71 36.806 -39.4261 0.0765 0.5759 4.75163 5,443,089
Mix 0.9584 43 0.5132 95.69 64.861 -18.1700 0.1125 3.2018 4.91979
5,635,716 Mix 0.9658 44 0.5132 60.97 100.976 -77.4158 0.0032 0.6625
6.40563 7,337,775 Liq -56.28.degree. F. 45 0.3248 134.31 38.306
54.5222 0.2278 15.2508 0.17552 201,067 Mix 0.9428 70 0.3015 180.60
89.976 67.6314 0.2420 20.8909 0.00000 0 Mix 1 71 0.3015 143.85
39.056 67.6313 0.2450 19.3202 0.00000 0 Mix 0.9446 72 0.3015 180.60
89.976 67.6314 0.2420 20.8909 0.86243 987,928 Mix 1 73 0.3015
143.06 38.306 67.6313 0.2452 19.2540 0.86243 987,928 Mix 0.9435 100
0.8100 85.97 3,028.000 6.1197 0.0765 47.5287 1.00000 1,145,520 Liq
-466.2.degree. F. 101 0.8100 268.57 2,998.000 224.5656 0.4207
87.3995 1.00000 1,145,520 Liq -281.92.degree. F. 102 0.8100 504.48
2,958.000 720.6200 1.0040 280.9530 1.00000 1,145,520 Vap
261.5.degree. F. 103 0.8100 836.22 2,908.000 1,048.5341 1.3021
454.2381 1.00000 1,145,520 Vap 593.3.degree. F. 104 0.8100 1,076.89
2,873.000 1,243.4311 1.4414 576.8966 1.00000 1,145,520 Vap
834.degree. F. 105 0.8100 1,050.00 950.116 1,251.24 1.5709 517.5241
1.00000 1,145,520 Vap 671.5.degree. F. 106 0.8100 836.22 985.116
1,093.7246 1.4544 420.4401 1.00000 1,145,520 Vap 455.1.degree. F.
107 0.8100 593.19 105.910 956.7157 1.5898 213.1765 1.00000
1,145,520 Vap 357.degree. F. 108 0.8100 308.74 90.910 790.3462
1.4235 133.1037 1.00000 1,145,520 Vap 80.8.degree. F. 109 0.8100
1,076.00 2,823.000 1,243.4311 1.4433 575.8861 1.00000 1,145,520 Vap
833.1.degree. F. 110 0.8100 371.74 94.232 825.9539 1.4639 147.7179
1.00000 1,145,520 Vap 141.9.degree. F. 111 0.8100 341.74 2,985.594
332.3002 0.5615 122.1159 1.00000 1,145,520 Liq -208.05.degree. F.
117 0.8100 0.00 14.693 0.0000 0.0000 0.0000 0.00000 0 Mix 0 129
0.8100 79.91 796.242 -5.2335 0.0731 37.9159 1.00000 1,145,520 Liq
-145.1.degree. F. 138 0.8100 185.60 39.056 728.1070 1.4307 67.1204
1.00000 1,145,520 Mix 0 Heat Source 600 GAS 1,134.10 15.416
351.4434 0.4542 136.5076 4.46873 5,119,020 Vap 1022.5.degree. F.
601 GAS 1,134.10 15.416 351.4434 0.4542 136.5076 2.47137 2,831,001
Vap 1022.5.degree. F. 602 GAS 1,134.10 15.416 351.4434 0.4542
136.5076 1.99736 2,288,019 Vap 1022.5.degree. F. 603 GAS 851.23
15.208 272.5814 0.4007 85.3904 2.47137 2,831,001 Vap 740.1.degree.
F. 605 GAS 851.23 15.208 272.5814 0.4007 85.3904 4.46873 5,119,020
Vap 740.1.degree. F. 606 GAS 851.23 15.208 272.5814 0.4007 85.3904
1.99736 2,288,019 Vap 740.1.degree. F. 607 GAS 578.19 15.024
199.2017 0.3389 44.0996 4.46873 5,119,020 Vap 467.5.degree. F. 608
GAS 293.74 14.822 125.4257 0.2568 12.8823 4.46873 5,119,020 Vap
183.5.degree. F. 609 GAS 108.72 14.693 76.5425 0.1827 2.4190
4.46873 5,119,020 Mix 0.0019 610 GAS 356.74 14.868 141.5658 0.2772
18.4650 4.46873 5,119,020 Vap 246.4.degree. F. 611 GAS 578.19
15.024 199.2017 0.3389 44.0996 6.72379 7,702,240 Vap 467.5.degree.
F. 612 GAS 293.74 14.822 125.4257 0.2568 12.8823 6.72379 7,702,240
Vap 183.5.degree. F. 621 GAS 578.19 15.024 199.2017 0.3389 44.0996
2.25506 2,583,220 Vap 467.5.degree. F. 622 GAS 293.74 14.822
125.4257 0.2568 12.8823 2.25506 2,583,220 Vap 183.5.degree. F.
Coolant 50 Water 51.70 14.693 19.8239 0.0394 0.0948 26.9165
30,833,419 Liq -160.25.degree. F. 51 Water 51.79 24.693 19.9424
0.0396 0.1233 26.9165 30,833,419 Liq -187.57.degree. F. 52 Water
66.58 14.693 34.7184 0.0682 0.0977 26.9165 30,833,419 Liq
-145.38.degree. F. 53 Water 51.70 14.693 19.8239 0.0394 0.0948
13.8526 15,868,401 Liq -160.25.degree. F. 54 Water 51.79 24.693
19.9424 0.0396 0.1233 13.8526 15,868,401 Liq -187.57.degree. F. 55
Water 69.06 14.693 37.1957 0.0729 0.1391 13.8526 15,868,401 Liq
-142.9.degree. F. 56 Water 51.70 14.693 19.8239 0.0394 0.0948
3.70679 4,246,203 Liq -160.25.degree. F. 57 Water 51.79 24.693
19.9424 0.0396 0.1233 3.70679 4,246,203 Liq -187.57.degree. F. 58
Water 79.53 14.693 47.6627 0.0925 0.4385 3.70679 4,246,203 Liq
-132.43.degree. F.
[0115] All references cited herein are incorporated by reference.
Although the invention has been disclosed with reference to its
preferred embodiments, from reading this description those of skill
in the art may appreciate changes and modification that may be made
which do not depart from the scope and spirit of the invention as
described above and claimed hereafter.
* * * * *