U.S. patent application number 11/322344 was filed with the patent office on 2006-06-08 for method of and apparatus for producing uniterruptible power description.
This patent application is currently assigned to ORMAT TECHNOLOGIES, INC.. Invention is credited to Lucien Y. Bronicki.
Application Number | 20060117753 11/322344 |
Document ID | / |
Family ID | 27119739 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060117753 |
Kind Code |
A1 |
Bronicki; Lucien Y. |
June 8, 2006 |
Method of and apparatus for producing uniterruptible power
description
Abstract
Uninterruptible power is supplied to a load connected to a power
line by connecting the power line to a rotatable member that
includes a Rankine cycle turbine coupled to a device that operates
as a motor when line power is operative thereby rotating the member
at a standby rotational speed so that a predetermined amount of
kinetic energy is stored in the rotating member, and that operates
as a generator when the line power is inoperative and the member is
rotated by the application of vaporized working fluid to the
turbine. Working fluid is vaporized and maintained at an
operational temperature level only when the line power is
inoperative. The working fluid is held at a standby temperature
level, preferably greater than the operational temperature level,
while the power line is operative whereby the working fluid
contains a predetermined amount of stored thermal energy while the
power line is operative. In response to loss of line power,
vaporized working fluid is applied to the turbine thereby rotating
the rotatable member whereby the turbine rotates the member at a
nominal operational speed that preferably is less than the standby
rotational speed. Finally, in response to the loss of line power
the device is connected to the load whereby the stored thermal
energy in the working fluid and the stored kinetic energy in the
rotating member are converted by the device to power for the
load.
Inventors: |
Bronicki; Lucien Y.; (Yavne,
IL) |
Correspondence
Address: |
Gary M. Nath;NATH & ASSOCIATES PLLC
112 South West Street
Alexandria
VA
22314
US
|
Assignee: |
ORMAT TECHNOLOGIES, INC.
Sparks
NV
|
Family ID: |
27119739 |
Appl. No.: |
11/322344 |
Filed: |
January 3, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10470800 |
Feb 24, 2004 |
6981378 |
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PCT/US02/21866 |
Feb 11, 2002 |
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11322344 |
Jan 3, 2006 |
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09917812 |
Jul 31, 2001 |
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10470800 |
Feb 24, 2004 |
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09780672 |
Feb 12, 2001 |
6494042 |
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10470800 |
Feb 24, 2004 |
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Current U.S.
Class: |
60/646 |
Current CPC
Class: |
Y04S 20/20 20130101;
Y02B 70/30 20130101; F01K 25/085 20130101; H02J 9/08 20130101; F01K
13/02 20130101 |
Class at
Publication: |
060/646 |
International
Class: |
F01K 13/02 20060101
F01K013/02; F01K 21/06 20060101 F01K021/06 |
Claims
1.-6. (canceled)
7. An uninterruptible power supply associated with a power line
supplying a load comprising: (a) a load circuit connecting said
power line to said load for powering the same when said power line
is operable; (b) a battery system for supplying power to the load;
(c) an electric generator associated with a cold standby power unit
comprising an organic Rankine cycle turbine system for generating
power when said power unit is operated, said organic Rankine cycle
turbine system having a boiler containing liquid organic working
fluid, a burner for heating said liquid organic working fluid
contained in said boiler, an organic Rankine cycle turbine for
expanding organic working fluid vapor produced in said boiler and
driving said generator for producing electric power, and a
condenser for condensing expanded working fluid vapor exiting said
organic Rankine cycle turbine; (d) a control that senses the state
of the power line such that the power unit commences operation for
supplying power to said load when line power drops out wherein said
battery supplies power to said load until nominal power is produced
by said power unit; and (e) a pump for supplying the working fluid
condensate produced by said condenser to the boiler and portion
thereof to the bearings of said turbine for lubricating said
bearings.
8. The uninterruptible power supply according to claim 7 wherein
said organic working fluid comprises a mixture of isomers of an
alkalyted aromatic fluid.
9. The uninterruptible power supply according to claim 7 wherein
said power unit further includes conduits for supplying said
working fluid condensate to said boiler and a portion thereof to
the bearings of said turbine for lubricating said bearings.
10. The uninterruptible power supply according to claim 7 wherein
said control includes a connection to said burner for sending a
control signal to the burner to commence operation once said
control senses that said power line has dropped out.
11. An uninterruptible power supply associated with a power line
supplying a load comprising: (a) a load circuit connecting said
power line to said load for powering the same when said power line
is operable; (b) a battery system for supplying power to the load;
(c) an electric generator associated with a cold standby power unit
comprising a Rankine cycle turbine system for generating power when
said power unit is operated, said Rankine cycle turbine system
having a boiler containing liquid working fluid, a burner for
heating said liquid working fluid contained in said boiler, a
Rankine cycle turbine for expanding working fluid vapor produced in
said boiler and driving said generator for producing electric
power, and a condenser for condensing expanded working fluid vapor
exiting said Rankine cycle turbine; (d) a control that senses the
state of the power line such that the power unit commences
operation for supplying power to said load when line power drops
out wherein said battery supplies power to said load until nominal
power is produced by said power unit; and (e) a pump for supplying
the working fluid condensate produced by said condenser to the
boiler and a portion thereof to the bearings of said turbine for
lubricating said bearings.
12. The uninterruptible power supply according to claim 11 wherein
said working fluid is an organic working fluid.
13. The uninterruptible power supply according to claim 12 wherein
said organic working fluid comprises a mixture of isomers of an
alkalyted aromatic fluid.
14. The uninterruptible power supply according to claim 11 wherein
said power unit further includes conduits for supplying said
working fluid condensate to said boiler and a portion thereof to
the bearings of said turbine for lubricating said bearings.
15. The uninterruptible power supply according to claim 11 wherein
said condenser is an air-cooled condenser.
16. The uninterruptible power supply according to claim 11 wherein
said condenser is an air-cooled condenser having a fan.
17. The uninterruptible power supply according to claim 11 wherein
said control includes a connection to said burner for sending a
control signal to the burner to commence operation once said
control senses that said power line has dropped out.
18. The uninterruptible power supply according to claim 11 wherein
said Rankine cycle turbine further comprises an organic Rankine
cycle turbine.
19. A power unit for use as a cold standby power unit comprising:
(a) a battery system for supplying power to the load; (b) an
electric generator associated with a cold standby power unit
comprising a Rankine cycle turbine system for generating power when
said power unit is operated, said Rankine cycle turbine system
having a boiler containing liquid working fluid, a burner for
heating said liquid working fluid contained in said boiler, a
Rankine cycle turbine for expanding working fluid vapor produced in
said boiler and driving said generator for producing electric
power, and a condenser for condensing expanded working fluid vapor
exiting said Rankine cycle turbine; (c) a control that senses the
state of the power line such that the power unit commences
operation for supplying power to said load when line power drops
out wherein said battery supplies power to said load until nominal
power is produced by said power unit; and (d) a pump for supplying
the working fluid condensate produced by said condenser to the
boiler and a portion thereof to the bearings of said turbine for
lubricating said bearings.
20. The power unit according to claim 19 wherein said working fluid
is an organic working fluid.
21. The power unit according to claim 19 wherein said organic
working fluid comprises a mixture of isomers of an alkalyted
aromatic fluid.
22. The power unit according to claim 19 wherein said power unit
further includes conduits for supplying said working fluid
condensate to said boiler and a portion thereof to the bearings of
said turbine for lubricating said bearings.
23. The power unit according to claim 22 further comprising a
reservoir from which working fluid liquid is supplied to the
bearings of said Rankine cycle turbine.
24. The power unit according to claim 23 further comprising a
conduit for supplying working fluid liquid from said reservoir to
said boiler.
25. The power unit according to claim 19 wherein said Rankine cycle
turbine further comprises an organic Rankine cycle turbine.
26. The power unit according to claim 19 wherein said condenser is
an air-cooled condenser.
27. The power unit according to claim 26 wherein said condenser is
an air-cooled condenser having a fan.
28. The power unit according to claim 19 wherein said control
includes a connection to said burner for sending a control signal
to the burner to commence operation once said control senses that
said power line has dropped out.
29. The uninterruptible power supply according to claim 9 further
comprising a reservoir from which working fluid liquid is supplied
to the bearings of said organic Rankine cycle turbine.
30. The uninterruptible power supply according to claim further
comprising a conduit for supplying working fluid liquid m said
reservoir to said boiler.
31. The uninterruptible power supply according to claim further
comprising a reservoir from which working fluid liquid supplied to
the bearings of said Rankine cycle turbine.
32. The uninterruptible power supply according to claim further
comprising a conduit for supplying working fluid liquid m said
reservoir to said boiler.
Description
TECHNICAL FIELD
[0001] This invention relates to a method of and apparatus for
producing power, and more particularly, to a method of and
apparatus for producing uninterruptible power for communication
systems that are located in urban areas or in the vicinity of towns
and also stand alone power systems for communication installations
in remote areas.
BACKGROUND OF THE INVENTION
[0002] Uninterruptible power systems particularly in communication
systems often utilize photovoltaic systems, thermoelectric
generators (TEG) or organic Rankine cycle energy converters. A
diesel engine based uninterruptible power sources (UPS) utilizes
batteries or a flywheel to supply an electrical load when line
power drops out and until the diesel can start and bring the
generator on line.
[0003] In telecommunications systems, redundant organic Rankine
cycle energy converters each operating at partial load have been
used so that, failure of one converter causes the other converter
to supply the full load. A transient period, until which the second
energy converter delivers the full load, which can last from a few
minutes up to about 20-50 minutes can be reduced by a standard
battery that delivers a few ampere-hours.
[0004] Since 1976, as part of the Trans-Alaska Pipeline Project, a
large number of stations have been operating each using a single
Organic Rankine cycle turbine unit as a warm standby unit to ensure
the required reliability. In such a standby unit, a line-operated
electric heater under themostatic control provides external heat to
a vapor generator of the unit to maintain the working fluid at
about 120.degree. F. When power fails, the main burner is activated
quickly bringing the organic vapor Rankine cycle turbine unit on
line delivering full power to the station as described in
Trans-Alaska Pipeline, Remote Gate Valve Equipment Buildings,
Operation and Maintenance Manual, Volume II, Ormat Energy Converter
Model 155, April 1976).
[0005] In a related system disclosed in U.S. Pat. No. 4,982,569,
the disclosure of which is hereby incorporated by reference, a
hybrid power system is disclosed that includes an intermittently
operable non-fuel consuming power generator, such as a photovoltaic
cell array, or a wind generator, connected through a control
circuit to a battery for changing the same and for supplying
current to a timewise, substantially constant, electrical load. In
addition, this hybrid power plant includes an electric generator
connected to an intermittently operable prime mover, such as a
Rankine cycle organic vapor turbogenerator, for charging the
battery and supplying current to the electrical load when the prime
mover is operated, and a sensor for sensing at least one electrical
parameter of the power plant. With such an arrangement, the prime
mover is operable only when the power generator is not
operating.
[0006] In another related system disclosed in U.S. Pat. No.
4,760,705, the disclosure of which is hereby incorporated by
reference, the invention disclosed therein relates to a Rankine
cycle power plant operating with an improved working fluid, the
working fluid being a compound selected from the group consisting
of bicyclic aromatic hydrocarbons, substituted bicyclic aromatic
hydrocarbons, heterocyclic aromatic hydrocarbons, substituted
heterocyclic aromatic hydrocarbons, bicyclic or heterobicyclic
compounds where one ring is aromatic and the other condensed ring
in a non-aromatic, and their mixtures. In a further aspect of the
invention disclosed in this U.S. patent, a binary Rankine cycle
power plant is provided in which the condenser of the high
temperature and pressure turbine is cooled by a different working
fluid which is vaporized thereby and supplied to a low temperature
and pressure turbine.
[0007] Israel Patent 43547 discloses a further related system and
discloses a rotor for a homopolar electrical machine.
[0008] Batteries are used in all the telecommunication projects to
provide DC power to the telecom equipment and the reliability and
availability of the system depends strongly on the battery
characteristics.
[0009] The batteries have a limited lifetime and if not properly
charged and maintained they have to be replaced a few times during
the life of a project estimated as 20-25 years.
[0010] In addition, because the battery condition cannot be
correctly assessed, battery failure occurs without any kind of
advance notice, station shut-down often occurs unexpectedly.
Moreover, the battery fails when they are actually needed so that,
when there is an electrical grid power outage, the diesel generator
fails when it is attempted to start it consequently causes the
battery, UPS and diesel generator not to provide power.
[0011] It is therefore an object of the present invention to
provide a new and improved method of and apparatus for providing
uninterruptible power wherein the disadvantages as outlined are
reduced or substantially overcome.
SUMMARY OF THE INVENTION
[0012] According to the present invention, an uninterruptible power
supply associated with a power line for supplying a load includes a
load circuit connected said power line to said load for powering
the same while said power line is operative, and a rotatable member
including a Rankine cycle turbine coupled to a device that operates
as a motor when line power is inoperative and this member is
rotated by the application of vaporized working fluid to the
turbine. A driver circuit connects the power line to the device
thereby rotating the rotatable member at a standby rotational speed
while the power line is operative for storing a predetermined
amount of kinetic energy in the rotating member. The power supply
also includes a boiler containing working fluid, a burner
associated with said boiler operable to produce vaporized working
fluid and to maintain the same at an operational temperature level
when the line power is inoperative, and resistance heater
associated with the boiler and connected to the power line for
holding the working fluid at a standby temperature level while the
power lind is operative, the standby level of the boiler being
preferably greater than the operational level of the boiler whereby
the working fluid contains a predetermined amount of thermal energy
while the power line is operative. A valve is operable to connect
the boiler to the turbine for applying vaporized working fluid to
the turbine thereby rotating the rotatable member, and a control is
responsive to loss of line power (1) for operating the burner,
which causes the boiler to produce vaporized working fluid, and for
operating the valve, which supplies vaporized working fluid to the
Rankine cycle turbine which thereby rotates the member at a nominal
operational speed preferably that is less than the standby
rotational speed, and (2) for connecting the device to the load
whereby power is supplied to the load while the power line is
inoperative, the thermal energy in the working fluid in the boiler
and the predetermined amount of kinetic energy being converted by
the device to power for the load upon loss of line power.
[0013] In addition, the present invention includes a method for
supplying uninterruptible power to a load connected to a power line
comprising connecting the power line to a rotatable member
comprising a Rankine cycle turbine coupled to a device that
preferably operates as a motor when line power is applied to the
device thereby rotating the member at a standby rotational speed
for storing a predetermined amount of kinetic energy in the
rotating member, and that operates as a generator when the line
power is inoperative, the member being rotated by the application
of vaporized working fluid to the turbine. Additionally, the method
includes vaporizing working fluid and maintaining the same at an
operational temperature level only when the line power is
inoperable. Furthermore, the method includes holding working fluid
at a standby temperature level while the power line is operative,
the standby temperature level preferably being greater than the
operational temperature level whereby the working fluid contains a
predetermined amount of stored thermal energy while power line is
operative. In addition, the method includes applying the vaporized
working fluid to the turbine thereby rotating the rotatable member
in response to loss of line power whereby the turbine rotates the
member at a nominal operational speed that is preferably less than
the standby rotational speed. Moreover, the method includes
connecting the device to the load whereby power is supplied to the
load while the power line is inoperative so that the stored thermal
energy in the working fluid and the predetermined amount of kinetic
energy are converted to power for the load upon loss of line
power.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Embodiments of the present invention are described by way of
example, and with reference to the accompanying drawings
wherein:
[0015] FIG. 1A-1B are schematic diagrams of an embodiment of the
present invention showing different modes or phases of
operation;
[0016] FIG. 2 is a schematic diagram of an embodiment of the
present invention;
[0017] FIG. 3 is a schematic diagram of a modification of the
embodiment of the present invention shown in FIG. 2;
[0018] FIG. 4 is a schematic diagram of a further modification of
the embodiment of the present invention shown in FIG. 2;
[0019] FIG. 5 is a schematic diagram of an additional embodiment of
the present invention;
[0020] FIG. 6 is a schematic diagram of still another embodiment of
the present invention; and
[0021] FIG. 7 is a schematic diagram of further embodiment of the
present invention.
[0022] Like reference numerals and designations in the various
drawings refer to like elements.
DETAILED DESCRIPTION
[0023] Turning to the Figures, FIGS. 1A and 1B show shematically
the main phases of operation of the preferred embodiment of the
present invention, the phases being designated as Phases 0, 1a, 1b
and 1c and representing the configuration of the apparatus as a
function of events that occur in the operation of the apparatus.
Phase 0 occurs when an electric utility supplies line power to a
load, this phase lasting as long as line power is operative. In
Phase 0, the apparatus is in a hot standby rotational speed, and
working fluid in boiler 53 is maintained at an operational
temperature level by a resistance heater connected to the line.
[0024] Phase 1a occurs in response to the loss of line power, and
typically last for a few seconds as spin-down of turbine 57 causes
generator 73 to deliver energy to the load. Upon loss of power,
working fluid is applied to turbine 57 and fuel is delivered to
burner 51.
[0025] Phase 1b typically last for a few minutes after loss of line
power occurs as stored thermal energy in boiler 53 is converted to
electricity and delivered to the load. At the end of phase 1b, the
burner is delivering sufficient heat to the boiler to maintain the
same at an operational temperature level at which the turbine
operation sustains the load. At this time, Phase 1c occurs as long
as the line remains inoperative and the fuel is not exhausted.
[0026] In phase 0 (see FIG. 1A) power is supplied by the electric
utility to the load by rectifier 76 as well as the AC input being
supplied to motor 52 that maintains or drives turbine 57 so that it
is rotated. In this phase, electric heater 54, supplied by AC line
power supplied by the utility, preferably maintains the temperature
of vapor generator or boiler 53 at a temperature above its normal
operating temperature (normal operation or normal operating
conditions being conditions during phase 1c described below).
However, on the other hand, the temperature of boiler or vapor
generator 53 can be maintained at the same temperature as that when
normal operation takes place (see phase 3 described below). In
addition, in phase 0, if preferred, motor 52 maintains the speed of
turbine 57 above its normal operating speed (normal operation or
normal operating conditions being conditions during phase 1c
described below). However, on the other hand, the speed of turbine
57 can be maintained at its normal operating speed i.e. during
normal operation (see phase 1c described below). In phase 1a (see
FIG. 1B), a utility failure occurs so that no line power is
available and the power is supplied to the load for a short period
of time (e.g. some seconds) by Rankine cycle turbine 57 utlitizing
its inertia or kinetic energy via generator 73 and rectifier 76.
Thereafter, in phase 1b (see also FIG. 1B), power is supplied to
the load by Rankine cycle turbine 57 via generator 73 and rectifier
76 utlizing the thermal energy present in boiler or vapor generator
53. In phase 1c (see FIG. 1B as well), power is supplied by Rankine
cycle turbine 57, under its normal operating conditions, to the
load via generator 73 and rectifier 76 wherein boiler or vapor
generator 53 now supplies the vapors to Rankine cycle turbine 57
from heat supplied from the combustion gases produced by burner
51.
[0027] Thus, the Rankine cycle turbine is maintained at hot standby
conditions wherein the hot standby Rankine cycle turbine is the
rotating Rankine cycle turbine 57 and boiler or vapor generator 53
in a state of incipient rate flow of vaporized working fluid. In
such a manner, the Rankine cycle turbine system, having the
rotating Rankine cycle turbine 57 and hot boiler or vapor generator
53, in phase 0, is at hot standby ready to provide the required
continuous operation to ensure that the load is continuously
supplied with the required power.
[0028] As far as FIG. 2 is concerned, power unit system 10A is
provided according to an embodiment of the present invention for
providing uninterruptible power and includes organic Rankine cycle
turbine 57A designed to operate as a hot standby organic Rankine
cycle turbine system 50A. In the present embodiment, hot standby
organic Rankine cycle turbine system 50A includes electric motor
52A for rotating the turbine when electric power is available from
the electric grid. The embodiment also includes boiler 53A and
heater 51A comprising e.g. a burner for combusting fuel. In
addition, the present embodiment includes electric heater 54A for
heating the liquid organic working fluid in the boiler when
electric line power is available from the electric grid or utility.
Moreover, in the present embodiment, valve 55A is included that
enables the supply of organic working fluid vapor to turbine 57A
for its nominal operation, when electric power is not available
from the electric grid.
[0029] In operation, when the electric grid or utility is supplying
electric line power, electric motor 52A rotates turbine 57A via
driver 75A that receives power from the grid. Line 66A receives
sufficient organic working fluid vapor from boiler 53A, heated by
electric heater 54A, for supplying fluid only to bearings 56A.
Heater, i.e. burner, 51A is not operated and preferably a flap
located on the stack of boiler 53A is maintained in a closed state
by an actuator. Thus, liquid supplied via line 66A is supplied to
reservoir 64A. This condensate is supplied via line 65A where it is
cooled to bearings 56A. Condensate exiting the bearings is supplied
via pump 67A, e.g. a pitot pump, to reservoir 64A from where it is
returned to bearings 56A. Electric heater 54A continues to supply
heat to organic working fluid in boiler 53A for compensating for
fluid finding its way back via line 68A to vessel 69A in heat
relationship with boiler 53A. Thus, under such conditions, the
electric grid supplies power to the load and the organic Rankine
cycle turbine system is maintained at hot standby.
[0030] When the electric grid does not supply electric power,
kinetic energy present in turbine 57A permits power unit 10A to
continue to supply electric power even though no electric power is
supplied to electric motor 52A from the electric grid or utility.
Valve 55A is opened by control unit 85A, which senses the state of
the line power, in order that organic working fluid vapor is
supplied from boiler 53A via conduit 71A to turbine nozzle block
70A. Consequently, power is now produced by the rotation of organic
Rankine cycle turbine 57A rotated by organic working fluid vapor
produced by heat present in the hot organic working fluid present
in boiler 53A. At the same time, the actuator opens the flap and
heater, i.e. burner, 51A, commences operation with the receipt of a
control signal from control unit 85A that also sends a control
signal to open fuel valve 72A. In addition, control unit 85A sends
a control signal to electric heater 54A to stop operation. The
rotation of organic Rankine cycle Turbine 57A results in generator
73A producing electric power that can be supplied to the load.
Thus, now the heat produced by the combustion gasses from burner
51A heats the working fluid in boiler 53A that produces vapors for
supply to turbine 57A.
[0031] When electric power becomes available from the electric grid
once again, control 85A senses the electric power and sends control
signals to heater, i.e. burner, 51A, to switch off, to the flap to
open, to electric heater 54A to switch on and to close valve 55A so
that no organic working fluid vapor is supplied via this valve to
organic Rankine cycle turbine 57A. Organic working fluid liquid
continues to be suppied to 56A of turbine 57A as previously
described via line 66A, reservoir 64A and line 65A.
[0032] Thus, in accordance with the present invention and with
reference to FIG. 2, in standby mode or Phase 0 (see FIG. 1A) when
line or utility power is available to supply the load, turbine 57A
is driven by motor 52A. Also in this mode, boiler 53A is heated by
resistance or electric heater 54A receiving line power from the
utility or electric grid. Working fluid liquid supplied to
reservoir 64A is cooled in line 65A and is supplied to bearings 56A
for providing lubrication of the bearings during rotation of
turbine 57A.
[0033] In transient mode, phase 1a (see FIG. 1B), when utility
failure occurs and line power is interrupted, kinetic energy
present in turbine 57A permits the turbine to continue rotating so
that generator 73A produces power that is supplied to the load via
rectifier 76A. Also, at the same time, valve 55A begins to open so
that organic working vapor can be supplied from boiler 53A via
conduit 71A to turbine nozzle block 70A in order that vapors are
supplied to turbine 57A for rotating it. In addition,
simultaneously, ignition of burner 51A commences while electric
heater 54A is switched off. Thereafter, in phase 1b (see FIG. 1B),
valve 55A having completed opening and continues to supplie vapors
to turbine 57A using heat present in boiler or vapor generator 53A,
generator 73A produces power that is supplied to the load, fuel
valve 72A opens and burner 51A. Consequently, boiler 53A quickly
produces rated flow of vaporized working fluid.
[0034] Subsequently, when line power is unavailable, phase 1c (see
FIG. 1B), in an active mode, boiler 53A, heated by the continuous
operation of burner 51A, supplies rated flow of vaporized working
fluid to turbine 57A that drives generator 73A for supplying power
to the load.
[0035] Turning to FIG. 3, numeral 10B designates a further
embodiment of a power unit system provided for supplying
uninterruptible power in accordance to the present invention. It
comprises a power unit system very similar to the embodiment
described with reference to FIG. 2 and operates on an organic
working fluid. However, in the embodiment described with reference
to FIG. 3, motor/generator 52B is included such that when electric
power is available at the electric grid motor/generator 52B
operates as a motor for rotating turbine 57B. On the other hand,
when no electric power is available on the electric grid,
motor/generator 52B operates as an electric generator in order that
the rotation of turbine 57B results in motor/generator 52B
producing electric power that can be supplied to the load.
[0036] As far as FIG. 4 is concerned, numeral 10C designates an
additional embodiment of the present invention wherein a power unit
system is provided for supplying uninterruptible power in
accordance to the present invention. Also here, this embodiment is
similar to the embodiment described with reference to FIG. 1 and in
particular to the embodiment described with reference to FIG. 2 and
operates on an organic working fluid. In the present embodiment
rather than using on-off valve 55A or 55B as shown in FIGS. 1 and 2
respectively, conduit 59C feeds one turbine nozzle out several or
tens present in nozzle block 70C so that a few percent of the
organic working fluid vapors are fed to turbine 57C via conduit 59C
for rotating it.
[0037] Consequently, when electric power is available at the
electric grid, a small amount of organic working fluid vapor is
supplied via conduit 59C and one nozzle of nozzle block 70C to
turbine 57C for rotating the turbine. As a result, there is no need
in this embodiment for an electric motor for rotating turbine 57C
when electric power is available from the electric grid. In
addition, when no electric power is available on the electric grid,
control valve 86C that receives control signals from control unit
85C supplies organic working fluid vapor to the rest of the nozzles
in nozzle block 70C for rotating turbine 57C at full power.
[0038] In these embodiments, if preferred, electric generator 73A
in FIG. 2 can be a synchronous, homopolar, induction or permanent
magnet generator, while motor 52A can be an induction, synchronous
or permanent magnet motor.
[0039] Thus, in these embodiments, the use of organic Rankine cycle
turbine 57, 57A, 57B and 57C rotating when the line power is
available, eliminates the need for using a battery or
batteries.
[0040] In addition, while the above description refers to the
working fluid as an organic working fluid, the present includes
water and its use in the Rankine cycle turbine system. In addition,
of course, the water can be used as the working fluid in the
Rankine cycle power plant systems that form part of the previously
described embodiments.
[0041] As far as FIG. 5 is concerned, numeral 10D designates an
additional embodiment of the present invention for supplying
uninterruptible power in accordance to the present invention.
Basically, this embodiment is similar to previous described
embodiments of the present invention, except that, in the present
embodiment, the water working fluid is supplied from water storage
tank 90D via pump 56D to boiler 53D. Water storage tank 90D itself
is preferably supplied with treated water from water treatment
system 91D furnished with make-up water. In addition, in this
embodiment the low-pressure steam exiting turbine 57D, connected to
high frequency asynchronous generator/motor 73D, is supplied from
turbine exhaust manifold 60D via conduit 92D to stack or chimney
94D for exit to the atmosphere. Thus, turbine 57D has an
atmospheric exhaust, and comprises consequently a back-pressure
steam turbine. Furthermore, in an alternative according to the
present invention, conduit or line 92D is preferably tapered at its
outlet to stack 94D in order to assist the draft produced in the
stack or chimney. In such a case, flap F3 can be connected
externally to conduit or line 92D at its outlet 93D. In a further
alternative, according to the present invention, portion of the
exhaust steam exhausting turbine 57D present in conduit or line 92D
can be mixed with treated water supplied to boiler 53D in order to
directly preheat the water supplied to the boiler. In a still
further alternative, according to the present invention, exhaust
steam exhausting turbine 57D present in conduit or line 92D can be
used to indirectly preheat the treated water supplied to boiler
53D. Condensate produced during such preheating can be supplied to
water storage tank 90D.
[0042] Numeral 10E in FIG. 6 designates a still further embodiment
of the present invention for supplying uninterruptible power in
accordance to the present invention. Basically, this embodiment is
also similar to the previous described embodiments of the present
invention, and in particular to the embodiment, generator/motor 73E
is a synchronous or a homopolar generator/motor.
[0043] Turning now to FIG. 7, numeral 10F a still further
embodiment of the present invention for supplying uninterruptible
power in accordance to the present invention. Basically, this
embodiment is similar to previous described embodiments of the
present invention, except that, in the present embodiment, the
working fluid, specifically water, is circulated in power unit 50F
with the aid of pump 56F. In this embodiment, the low-pressure
steam exiting turbine 57F is supplied to turbine exhaust manifold
60F and then to condenser 62F, preferably an air-cooled condenser
having a fan for supplying air to the condenser tubes, for
producing steam condensate that is supplied using pump 56F to
boiler 53F. In this embodiment, generator/motor 52F connected to
turbine 57F can be a high frequency asynchronous generator/motor or
alternatively a synchronous or a homopolar generator/motor.
[0044] In operation, when the electric grid or utility is supplying
electric line power, electric motor/generator 52F operating as a
motor rotates turbines 57F via driver 75F that receives power from
the grid. Line 66F receives sufficient organic working fluid vapor
from boiler 53F, heated by electric heater 54F, for supplying fluid
only to bearings 56F. Heater, i.e. burner, 51F is not operated and
preferably a flap located on the stack of boiler 53F is maintained
in a closed state by an actuator. Thus, liquid supplied via line
66A is supplied to reservoir 64F. This condensate is supplied via
line 65A where it is cooled to bearings 56F. Condensate exiting the
bearings is supplied via pump 67F, e.g. a pitot pump, to reservoir
64F from where it is returned to bearings 56F. Electric heater 54F
continues to supply heat to organic working fluid in boiler 53AF
for compensating for fluid finding its way back via line 68F to
vessel 69F in heat relationship with boiler 53F. Thus, under such
conditions, the electric grid supplies power to the load and the
organic Rankine cycle turbine system is maintained at hot
standby.
[0045] When the electric grid does not supply electric power,
kinetic energy present in turbine 57F permits power unit 10F to
continue to supply electric power even though no electric power is
supplied to electric motor 52F from the electric grid or utility.
Valve 55F is opened by control unit 85F, which senses the state of
the line power, in order that organic working fluid vapor is
supplied from boiler 53F via conduit 71F to turbine nozzle block
70F. Consequently, power is now produced by the rotation of organic
Rankine cycle turbine 57F rotated by organic working fluid vapor
produced by heat present in the hot organic working fluid present
in boiler 53F. At the same time, the actuator opens the flap and
heater, i.e. burner, 51F, commences operation with the receipt of a
control signal from control unit 85F that also sends a control
signal to open fuel valve 72F. In addition, control unit 85A sends
a control signal to electric heater 54F to stop operation. The
rotation of organic Rankine cycle turbine 57F results in
motor/generator 52F, now operating as a generator, producing
electric power that can be supplied to the load. Thus, now the heat
produced by the combustion gases from the burner 51F heats the
working fluid in boiler 53F that produces vapors for supply to
turbine 57F.
[0046] When electric power becomes available from the electric grid
once again, control 85F senses the electric power and sends control
signals to heater, i.e. burner, 51F, to switch off, to the flap to
open, to electric heater 54F to switch on and to close valve 55F so
that no steam is supplied via this valve to organic Rankine cycle
turbine 57F. Liquid water continues to be supplied to bearings 56F
of turbine 57F as previously described via line 66F, reservoir 64F
and line 65F.
[0047] While the embodiment described with reference to FIGS. 5, 6
and 7 describe a generator/motor driven by turbine 57D, 57E and
57F, if preferred, a separate generator and motor, e.g. like motor
52A and generator 73A described with reference to FIG. 1, can be
used instead of the generator/motor.
[0048] In addition, it should be pointed out that the present
invention includes as well the method for operating the apparatus
disclosed with reference to above-described figures.
[0049] Moreover, it should be pointed out that, at present, the
embodiment of the present invention described with reference to
FIG. 3 is considered the best mode for carrying out the present
invention.
[0050] Furthermore, when an organic working fluid is used as the
working fluid in the Rankine cycle turbine system or systems, the
working fluid is preferably chosen from the group
chlorobenzene-dichlorobenzene, trichlorobenzene; bicyclic aromatic
hydrocarbons; substituted bicyclic aromatic hydrocarbons,
heterocyclic aromatic hydrocarbons, substituted heterocyclic
aromatic hydrocarbons, bicyclic or heterobicyclic compounds where
one ring is aromatic and the other condensed ring is non-aromatic,
and their mixtures such as naphthalene, 1-methyl-napthalene,
1-methyl-napthalene, tetralin, quinolene, benzothiophene; an
organic, alkylated heat transfer liquid fluid or a synthetic
alkylated aromatic heat transfer fluid, e.g. thermal oils such as
Therminol LT fluid (an alkyl substituted aromatic fluid), Dowtherm
J (a mixture of isomers of an alkylated aromatic fluid), isomers of
diethyl benzene and mixtures of the isomers and butyl benzene.
[0051] Furthermore, while the above description refers to a hot
standby mode of operation, the present invention is also
operational in a warm standby mode wherein a battery is provided in
addition to the Rankine cycle turbine system described above and
detailed in the above-mentioned embodiments. In the warm standby
mode, the battery provides power to the load after the line power
has stopped supplying power to the load or the electric utility had
failed and until the Rankine cycle turbine supplies the required
power to the load. In this embodiment, the boiler is maintained
warm (e.g. at about 60.degree. C.) by e.g. an electric heater, like
54A shown in FIG. 2, described above so that the period of time
needed for the Rankine cycle turbine to start supplying the
required power level to the load is relatively short (e.g. up to a
half hour). Thus, the battery used in this configuration is
relatively small.
[0052] In addition, the units described in accordance with the
present invention, can be used in a cold standby configuration,
wherein a large battery is provided for supply power to the load
when line power fails until nominal power is produced by the power
unit. In such a system, the power until will commence operation
when line power drops out.
[0053] Furthermore, in accordance with the present invention, the
power produced by the generator of the Rankine cycle turbine unit,
e.g. 73A of FIG. 2, etc., is preferably supplied to the load so
that it threshold voltage is lower than that supplied to the load
when line power is available. This permits the power produced by
the Rankine cycle turbine unit to be supplied automatically to the
load once the power from the grid or power utility had dropped
below a certain predetermined threshold value. In the arrangement
provided in accordance with the present invention, the need for
using an additional or external rectifier can be saved. However, on
the other hand, the line power can be supplied to the load via an
additional or external rectifier.
[0054] In addition, in accordance with the present invention, it
should be pointed out that operation of Rankine cycle turbine unit
using Therminol or Dowtherm J permits the unit to operate at a
relatively high temperature. When operating with these working
fluids, low losses in particular during standby operation when grid
or utility power is rotating the turbine are achieved. In addition,
such high temperature operation can reduce the size of the
condenser.
[0055] It is believed that the advantages and improved results
furnished by the method and apparatus of the present invention are
apparent from the foregoing description of the invention. Various
changes and modifications may be made without departing from the
spirit and scope of the invention as described in the claims that
follow.
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