U.S. patent application number 12/735662 was filed with the patent office on 2010-12-30 for cooling, heating and power system with an integrated part-load, active, redundant chiller.
Invention is credited to Lynn M. Rog, James Eric Vanderpas, Timothy C. Wagner, Kevin Wyman.
Application Number | 20100326098 12/735662 |
Document ID | / |
Family ID | 41065725 |
Filed Date | 2010-12-30 |
United States Patent
Application |
20100326098 |
Kind Code |
A1 |
Rog; Lynn M. ; et
al. |
December 30, 2010 |
COOLING, HEATING AND POWER SYSTEM WITH AN INTEGRATED PART-LOAD,
ACTIVE, REDUNDANT CHILLER
Abstract
A cooling, heating and power system (10) includes a prime mover
(12) for producing electricity having a thermal output (18) and an
electrical output (20) coupled to an absorption chiller (24). A
part-load, active, redundant chiller (26) is thermally coupled to
the absorption chiller (24) for receiving a cooling-heating fluid
from the absorption chiller (24). The part-load chiller (26)
operates at maximum efficiency at between about forty percent and
about sixty percent of a maximum cooling load of the chiller (26)
to thereby generate large volumes of cooling very efficiently. The
system (10) may direct the cooling into a multi-zone
cooling-heating circuit (40) including a critical zone (42) and a
utility zone (44) thermally coupled to the chiller (26) for
selectively delivering the cooling-heating fluid to at least one of
the critical zone (42) and the utility zone (44) of the circuit
(40).
Inventors: |
Rog; Lynn M.; (South
Windsor, CT) ; Wyman; Kevin; (West Hartford, CT)
; Wagner; Timothy C.; (East Hartford, CT) ;
Vanderpas; James Eric; (Sparta, NJ) |
Correspondence
Address: |
Malcolm J. Chisholm
P.O. Box 278
Lee
MA
01238
US
|
Family ID: |
41065725 |
Appl. No.: |
12/735662 |
Filed: |
March 12, 2009 |
PCT Filed: |
March 12, 2009 |
PCT NO: |
PCT/US2009/001584 |
371 Date: |
August 5, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61069276 |
Mar 12, 2008 |
|
|
|
Current U.S.
Class: |
62/101 ;
62/476 |
Current CPC
Class: |
F25B 2500/06 20130101;
F25B 27/00 20130101; F25B 25/00 20130101 |
Class at
Publication: |
62/101 ;
62/476 |
International
Class: |
F25B 15/00 20060101
F25B015/00 |
Claims
1. A cooling, heating and power system (10), the system (10)
comprising: a. a prime mover (12) for producing electricity having
a thermal output (18) and an electrical output (20); b. an
absorption chiller (24) thermally coupled to the thermal output
(18) and electrically coupled to the electrical output (20) of the
prime mover (12) for receiving heat and electricity from the prime
mover (12); c. a part-load, active, redundant chiller (24)
electrically coupled to the prime mover (12) for receiving
electricity from the prime mover (12), and thermally coupled to the
absorption chiller (24) for receiving a cooling-heating fluid from
the absorption chiller (24); and, d. wherein the part-load, active,
redundant chiller (26) operates at maximum efficiency at between
about forty percent and about sixty percent of a maximum cooling
capacity of the chiller (26).
2. The system (10) of claim 1, further comprising a system
controller (74) for controlling the absorption chiller (24) to
utilize a maximum amount of thermal energy generated by the prime
mover (12) while simultaneously controlling the part-load, active,
redundant chiller (26) to operate at maximum efficiency at between
about forty percent and about sixty percent of the maximum cooling
capacity of the chiller (26).
3. The system (10) of claim 1, wherein the part-load, active,
redundant chiller (26) is secured in electrical communication with
the prime mover (12) and with an exterior source (34) of
electricity not generated by the prime mover (12).
4. The system (10) of claim 1, further comprising a multi-zone
cooling-heating circuit (40) including a critical zone (42) and a
utility zone (44) thermally coupled to the part-load, active,
redundant chiller (26) through a circuit feed line (46) for
directing the cooling-heating fluid into the circuit (40) and by
way of a circuit pump (49) through a circuit return line (48) for
returning the fluid to the absorption chiller (24), and wherein the
multi-zone cooling-heating circuit (40) is configured for
selectively delivering the cooling-heating fluid from the active,
redundant chiller (26) to at least one of the critical zone (42)
and the utility zone (44) of the circuit (40).
5. The system (10) of claim 4, further comprising a circuit control
valve (54) for selectively delivering the cooling-heating fluid
from the active, redundant chiller (26) to at least one of the
critical zone (42) and the utility zone (44) of the circuit
(40).
6. The system (10) of claim 4, wherein the circuit (40) is
configured for directing flow of the cooling-heating fluid from the
at least one of the critical zone (42) and the utility zone (44)
back through the circuit return line (48) to at least one of the
absorption chiller (24) and the part-load, active, redundant
chiller (26).
7. The system (10) of claim 4, further comprising an absorption
chiller by-pass line (52) secured in fluid communication between a
by-pass valve (50) upstream of the absorption chiller (24) and the
part-load, active, redundant chiller (26), for selectively
directing the cooling-heating fluid returning from the
cooling-heating circuit (40) around the absorption chiller
(24).
8. The system (10) of claim 4, further comprising a part-load,
active, redundant chiller (26) by-pass line (70) in fluid
communication with a part-load, active, redundant chiller (26)
by-pass valve (72) secured in fluid communication between the
absorption chiller (24), and the circuit feed line (46) for
selectively directing the cooling-heating fluid to by-pass the
part-load, active, redundant chiller (26).
9. A method for providing cooling, heating and power, the method
comprising: a. directing recoverable waste heat from a prime mover
(12) into an absorption chiller (12); b. utilizing the waste heat
within the absorption chiller (24) to support operation of the
absorption chiller (24); c. directing flow of a cooling-heating
fluid through the absorption chiller (24) to cool the
cooling-heating fluid; d. controlling operation of the absorption
chiller (24) at about maximum cooling capacity of the absorption
chiller (24) while the cooling-heating fluid flows through the
absorption chiller (24); e. then, directing flow of the
cooling-heating fluid through a part-load, active, redundant
chiller (26) to further cool the, cooling-heating fluid; and, f.
operating the part-load, active, redundant chiller (26) at between
about forty percent and about sixty percent of a maximum cooling
load of the chiller (26).
10. The method of claim 9, further comprising controlling the
absorption chiller (24) to utilize a maximum amount of thermal
energy generated by the prime mover (12) while simultaneously
controlling the part-load, active, redundant chiller (26) to
operate at maximum efficiency at between about forty percent and
about sixty percent of the maximum cooling capacity of the chiller
(26).
11. The method of claim 9, further comprising selectively directing
flow of the cooling-heating fluid leaving the part-load, active,
redundant chiller (26) into at least one of a critical zone (42)
and a utility zone (44) of a multi-zone cooling-heating circuit
(40) secured in fluid communication with the chiller (26).
12. The method of claim 10, further comprising selectively
directing flow of the cooling-heating fluid from a circuit return
line (48) to by-pass the absorption chiller (24) by directing flow
of the cooling-heating fluid through an absorption chiller by-pass
line (52) secured in fluid communication between a by-pass valve
(50) upstream of the absorption chiller (24) and the part-load,
active, redundant chiller (26).
13. A method of delivering cooling to a multi-zone cooling-heating
circuit (40) having a critical zone (42) and a utility zone (44),
the method comprising: a. generating electricity and recoverable
waste heat within a prime mover (12); b. directing flow of the
generated waste heat into an absorption chiller (24); c. cooling a
cooling-heating fluid circulating through the multi-zone
cooling-heating circuit (40) by flowing the cooling-heating fluid
through the absorption chiller (24); d. further cooling the
cooling-heating fluid by then directing flow of the fluid through a
part-load, active, redundant chiller (26); and, e. selectively
directing flow of the cooled, circulating cooling-heating fluid
into at least one of the critical zone (42) and the utility zone
(44).
14. The method of claim 13, further comprising controlling the
absorption chiller (24) to utilize a maximum amount of waste heat
generated by the prime mover (12) while simultaneously controlling
the part-load, active, redundant chiller (26) to operate at maximum
efficiency at between about forty percent and about sixty percent
of a maximum cooling capacity of the chiller (26).
15. The method of claim 13, further comprising operating at peak
cooling by controlling the absorption chiller (24) to utilize a
maximum amount of waste heat generated by the prime mover (12)
while simultaneously controlling the part-load, active, redundant
chiller (26) to operate at between about ninety percent and about
one-hundred percent of a maximum cooling capacity of the chiller
(26), and directing flow of as much cooling from the chiller (26)
into the critical zone (42) as is necessary to satisfy cooling
requirements of the critical zone (42).
16. The method of claim 13, further comprising operating at
offnormal cooling whenever operation of the absorption chiller (24)
is interrupted by controlling the part-load, active, redundant
chiller (26) to operate at between about ninety percent and about
one-hundred percent of a maximum cooling capacity of the chiller
(26), and by directing flow of as much cooling from the chiller
(26) into the critical zone (42) as is necessary to satisfy cooling
requirements of the critical zone (42).
17. The method of claim 13, further comprising operating at
offnormal cooling whenever operation of the prime mover (12) is
interrupted by directing flow of electricity into the part-load,
active, redundant chiller (26) from an exterior source (34) of
electricity; by controlling the part-load, active, redundant
chiller (26) to operate at between about ninety percent and about
one-hundred percent of a maximum cooling capacity of the chiller
(26); and, by directing flow of as much cooling from the chiller
(26) into the critical zone (42) as is necessary to satisfy cooling
requirements of the critical zone (42).
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This Application claims the benefit of U.S. Provisional
Patent Application Ser. No. 61/069,276 that was filed on Mar. 12,
2008, entitled "Redundant Cooling Integrated with CHP".
TECHNICAL FIELD
[0002] The present disclosure relates generally to use of cooling,
heating and power systems (occasionally referred to as "CHP", or
"CCHP" for "combined cooling, heating and power") that include a
prime mover for producing electrical and/or mechanical energy that
is thermally and electrically coupled with an absorption chiller
for producing cooling and heating for such things as buildings
having data centers, hospitals, etc. More particularly, the
disclosure includes such a CHP system with an integrated part-load,
active, redundant electric chiller and a system controller to
provide more efficient cooling with a capacity for more efficient
peak and back up cooling capacity.
BACKGROUND ART
[0003] Providing cooling, heating and power to modern structures
such as buildings, oil drilling platforms, etc., increasingly
requires sensitivity to supplying adequate cooling to critical
zones of the structure. The critical zone most often includes data
centers having large computers, servers, etc. that generate a lot
of heat, wherein the heat must be removed from the data center to
support acceptable operation of the data apparatus therein. Other
heat sensitive, critical zones include hospital operating rooms and
intensive care units, refrigerated food processing centers, etc. It
is known to separate a supply of cooling, heating and power to such
critical zones from the supply of cooling, heating and power to
other less critical areas of the structure, referred to herein for
convenience as a "utility zone". In the event of an interruption of
a supply of power from an exterior source of electricity (e.g., the
"grid"), modern structures invariably include a backup electricity
supply to operate cooling chillers, heaters, and to supply
electrical power until the grid supply is returned. To minimize the
cost and complexity of such a backup system, it is known for
enhanced security of cooling, heating and power supply to have the
backup CHP source prioritize delivery of cooling, heating and power
to only the critical zone, or to satisfy all of the needs of the
critical zone and to supply any excess cooling, heating and/or
power to an adjoining utility zone.
[0004] An exemplary cooling, heating and power system includes as a
prime mover a one or more energy producing apparatus powered by
natural gas, wherein the energy producing apparatus power
electrical generators for supplying electricity to a structure.
(For purposes herein, the phrase "prime mover" is to mean any
energy production apparatus, including a diesel generator,
microturbine(s), a fuel cell(s), etc., that produces electrical
energy and recoverable waste heat.) Waste heat (e.g., hot exhaust
gas from the energy production apparatus) is directed to flow into
an absorption chiller to minimize power necessary to run the
chiller. Electricity is also directed from the prime mover to the
absorption chiller. The absorption chiller generates cooling and
heating that can be directed through thermal coupling into a
structure to remove heat from a data center, and to otherwise cool
and heat the structure depending upon demands of the structure.
[0005] Such a prime mover combined with an absorption chiller is
therefore a cooling, heating and power (CHP) system. Absorption
chillers are well known, such as disclosed in U.S. Pat. Nos.
7,065,976 and 7,273,071, both of which Patents are owned by the
owner of all rights in the present disclosure. A known CHP system
is available under the brand name "PureComfort Power Solution" from
UTC POWER, LLC of South Windsor, Conn., U.S.A. ("PureComfort" is a
registered trademark of UTC POWER, LLC.) An ordinary installation
of such a CHP system is for the system to be wired in parallel with
an exterior grid supply of electricity. During normal operation,
the CHP system, using natural gas, supplements the cooling, heating
and power requirements of an entire structure, thereby saving
energy and reducing dependency on the cost of grid supplied
electricity, and providing a more environmentally friendly energy
supply than the grid supply which depends largely upon coal and oil
generated electricity.
[0006] Existing electrical chillers operate under a range of
operating efficiencies. These efficiencies are impacted by the type
of vapor compression (centrifugal, screw, rotary scroll
compressors, etc.), the type of refrigerant (R-22, R-134a, R123,
R410, etc.) and the type of heat rejection (air-cooled or
water-cooled). Typical efficiencies for full load chillers
operating such as those that typically service critical data
services range from 0.45 kilowatt per refrigeration ton ("kW/RT")
to 0.90 kW/RT. It is known in the industry to have both ambient
relief on the heat rejection that favorably impacts efficiency.
Operating the units at less than full load impacts efficiency as
well.
[0007] In the event of an interruption of grid supplied
electricity, the CHP system would continue to operate while control
switches and valves would then direct adequate supplies of cooling,
heating and/or power from the CHP system to a critical zone of the
structure, such as a data center to ensure ongoing, uninterrupted
operation of the data apparatus, etc. Depending upon the nature of
the structure supported by the CHP system and the nature of the
grid interruption, alternative backup (e.g., diesel generators,
etc.) may also be activated to further support the critical and
utility zones of the structure. Whenever the grid supply is
returned, the CHP system would be controlled to supplement the
normal operating total supply of cooling, heating and power to the
structure.
[0008] Such a CHP system provides satisfactory supplemental and
backup supplies of cooling, heating and electrical power especially
to structures having a substantial critical zone, such as banks
having data centers that process credit card transactions,
switching centers of large communication networks, hospital
operating rooms, elevators, etc. A CHP system with a prime mover
that is electrically and thermally coupled to an absorption chiller
nonetheless gives rise to substantial concerns. For example, if
operation of the absorption chiller was interrupted due to a
mechanical failure, supply of additional cooling would have to be
supplied to the critical zone from an alternative chiller(s).
[0009] Alternatively if operation of the prime mover was
interrupted, the absorption chiller depending upon the waste heat
from the prime mover, would then also be unable to operate, again
requiring the overall cooling supply of the structure to include
alternative backup cooling sources. Additionally, the absorption
chiller must be dimensioned to satisfy demands of the critical zone
during periods of a peak load on the CHP system. For example,
during a heat wave in a metropolitan area, it is known that a grid
supply may suffer "brown-outs" while cooling demand is at an
absolute peak due to the heat wave. Design of a CHP system to
satisfy such a circumstance mandates that the absorption chiller be
uneconomically sized to perform occasionally at outputs
substantially beyond normal load operations. This adds further cost
and complexity to the CHP system and to an overall system that
provides all of the cooling, heating and power demands of the
structure.
[0010] Consequently, there is a need for a cooling, heating and
power system that resolves these and related concerns.
SUMMARY
[0011] The disclosure is directed to a cooling, heating and power
system that includes a prime mover for producing electricity that
has a thermal output and an electrical output. An absorption
chiller for producing cooling and heating is thermally coupled and
electrically coupled to the thermal output and the electrical
output of the prime mover for receiving heat and electricity from
the prime mover. A part-load, active, redundant chiller is
electrically coupled to the prime mover for receiving electricity
from the prime mover, and is also thermally coupled to the
absorption chiller for receiving a cooling-heating fluid from the
absorption chiller. A "part-load, active, redundant chiller"
consists of a chiller that operates most efficiently at part load,
such as between about forty percent ("40%") and about 60% of a
maximum cooling load.
[0012] By integrating the part-load, active redundant chiller to
operate downstream from the absorption chiller so that it receives
the cooling-heating fluid after it has been cooled by the
absorption chiller, the part-load, active redundant chiller may
operate at a very high rate of efficiency compared to the
part-load, active, redundant chiller operating alone to achieve a
required decrease in temperature of the cooling-heating fluid. For
example, if the circulating cooling-heating fluid must be reduced
in temperature by a total of 10 degrees by the cooling, heating and
power system, and the absorption chiller first reduces the
temperature by 5 degrees, the part-load, active, redundant chiller
can be sized to reduce the cooling-heating fluid the additional 5
degrees while operating at between about 40% to about 60% of its
capacity or "load", which is a highest efficiency operating point
of the part-load, active, redundant chiller. (For purposes herein,
the word "about" is to mean plus or minus 10%.) This permits the
part-load, active, redundant chiller to operate at a very high rate
of efficiency by reducing mechanical work required by the
part-load, active, redundant chiller. Then, if operation of the
absorption chiller is interrupted, the part-load, active, redundant
chiller may be controlled to operate at about one-hundred percent
load to satisfy the cooling demands of the critical zone. More
importantly, during normal operation of the system, by having the
electrically powered part-load, active, redundant chiller operate
downstream from the absorption chiller, both chillers may be sized
for minimal cost and maximum operating efficiency to thereby
deliver cooling to the multi-zone cooling-heating circuit at a very
low kilowatt per refrigeration ton ("kW/ton") value, while
providing enhanced cooling backup. In a preferred embodiment, the
part-load, active, redundant chiller is a high efficiency,
tri-screw electric chiller.
[0013] Integrating the part-load, active, redundant chiller
downstream from the absorption chiller also permits efficient
sizing of the absorption chiller so that the absorption chiller
does not have to be substantially over sized beyond normal load
conditions to meet peak loads described above. Instead, the
part-load, active, redundant chiller is dimensioned to be
responsive to normal loads on the system while operating at between
about 40% to about 60% load, and during peak load conditions, the
part-load, active, redundant chiller is controlled to increase
cooling capacity to meet the peak load conditions. If operation of
the absorption chiller is interrupted producing offnormal load
conditions, the part-load, active, redundant chiller may be
controlled to increase its cooling capacity from the efficient 40%
to 60% load to a load between about 60% and 100% to meet the
offnormal condition. Integration of the part-load, active,
redundant chiller with the absorption chiller and prime mover
therefore provides enormous efficiencies in manufacture, cost and
operation of the cooling, heating and power system of the present
disclosure.
[0014] The system may also include a multi-zone cooling-heating
circuit including a critical zone and a utility zone. The circuit
is thermally coupled to the part-load, active, redundant chiller
through a circuit feed line for directing the cooling-heating fluid
into the circuit and through a circuit return line for returning
the fluid to one of the absorption chiller and the part-load,
active, redundant chiller. The multi-zone cooling-heating circuit
includes a circuit control valve on the circuit feed line
configured for selectively delivering the cooling-heating fluid
from the part-load, active, redundant chiller to at least one of
the critical zone and the utility zone of the circuit. The circuit
is also configured for directing flow of the cooling-heating fluid
from the at least one of the critical zone and the utility zone
back through the circuit return line to at least one of the
absorption chiller and the part-load, active, redundant
chiller.
[0015] By integrating the part-load, active, redundant chiller with
the prime mover and the absorption chiller, in the event operation
of the absorption chiller is interrupted, the cooling-heating fluid
would continue to flow into the part-load, active, redundant
chiller to be chilled, and the circuit control valve would be
controlled to direct the cooling-heating fluid from the part-load,
active, redundant chiller only into the critical zone of the
multi-zone cooling-heating circuit. Alternatively, the circuit
control valve would be controlled to direct as much of the
cooling-heating fluid into the critical zone as is necessary to
satisfy cooling needs of the critical zone, while the remaining
fluid is directed into the utility zone. The multi-zone
cooling-heating circuit directs the cooling-heating fluid back from
the critical zone and optionally some fluid from the utility zone
through the circuit return line into either the non-operational
absorption chiller to flow through the absorption chiller, or
through an absorption chiller by-pass line directly into the
part-load, active, redundant chiller to be cooled again and to
continue circulating through the critical zone. Use of the
part-load, active, redundant chiller, therefore minimizes any need
for any further cooling backup for the critical zone while the
absorption chiller is being repaired, replaced, etc.
[0016] In the event operation of the prime mover is interrupted
which would terminate the thermal flow from the prime mover into
the absorption chiller thereby disrupting operation of the
absorption chiller, the part-load, active, redundant chiller may
continue to operate while receiving electricity from an alternative
source outside of the cooling, heating and power source, such as
the external grid supply of electricity. In such an event, the
circuit control valve of the multi-zone cooling-heating circuit
would direct flow of the cooling-heating fluid into the critical
zone as described above.
[0017] A primary use of the cooling, heating and power system with
an integrated part-load, active, redundant chiller is to
substantially decrease overall cooling costs as well as to
supplement, secure and backup the cooling, heating and power
requirements of a structure, such as a building having a critical
zone and a utility zone. It is to be understood that the present
disclosure may also be utilized as a stand alone cooling, heating
and power system without parallel electricity supplied by the grid,
such as to be the primary cooling, heating and power system for an
oil drilling platform or for similar stand alone usages. The
cooling, heating and power system of the present disclosure also
provides the above described advantages in such usages.
[0018] Accordingly, it is a general purpose of the present
disclosure to provide a cooling, heating and power system with an
integrated part-load, active, redundant chiller that overcomes
deficiencies of the prior art.
[0019] It is a more specific purpose to provide a cooling, heating
and power system with an integrated part-load, active, redundant
chiller that increases operating efficiencies of the system and
decreases manufacture, installation and operational costs of the
system.
[0020] These and other purposes and advantages of the present
cooling, heating and power system with an integrated part-load,
active, redundant chiller will become more readily apparent when
the following description is read in conjunction with the
accompanying drawing.
BRIEF DESCRIPTION OF DRAWING
[0021] FIG. 1 is a simplified schematic representation of a
cooling, heating and power system with an integrated part-load,
active, redundant chiller of the present disclosure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Referring to the drawings in detail, a cooling, heating and
power system with an integrated part-load, active, redundant
chiller of the present disclosure is generally designated by the
reference numeral 10. The system 10 includes a prime mover 12 that
receives fuel, such as natural gas, from a fuel source 14 through a
fuel inlet line 16 to produce electricity. The prime mover 12 may
be any apparatus capable of producing electricity, such as a
microturbine(s) mechanically coupled to an electric generator(s), a
diesel or gas engine, a fuel cell, etc., and that also generates
waste heat. The primer mover 12 also includes a thermal output 18
and an electrical output 20, and may also include a primary
electrical line 22 for delivering additional electricity produced
by the prime mover 12.
[0023] The system also includes an absorption chiller 24 for
producing cooling and heating and the absorption chiller 24 is
thermally coupled and electrically coupled to the thermal output 18
and the electrical output 20 of the prime mover 12 for receiving
heat and electricity from the prime mover 12. A part-load, active,
redundant chiller 26 (also referred to occasionally herein for
convenience as an "ARC") is electrically coupled through an ARC
prime mover electric feed line 28 to the prime mover 12 for
receiving electricity from the prime mover 12. The "part-load,
active, redundant chiller" 26 consists of a chiller that operates
most efficiently at part load, such as between about forty percent
("40%") and about 60% or a maximum load. The part-load, active
redundant chiller 26 is also thermally coupled through an ARC
thermal feed line 30 to the absorption chiller 26 for receiving a
cooling-heating fluid from the absorption chiller 26. An exterior
electric feed line 32 may also be included in the system 10 to
direct electricity from an exterior source 34 such as the electric
grid to the part-load, active, redundant chiller 26 through an
exterior feed line switch 36 on feed line 32. Preferably, the
part-load, active, redundant chiller 26 is plumbed to the
absorption chiller in a side streaming arrangement.
[0024] The cooling, heating and power system 10 of the present
disclosure may also include a multi-zone cooling-heating circuit 40
including a critical zone 42, and a utility zone 44. The multi-zone
cooling-heating circuit 40 may be installed in a structure, such as
a building (not shown), and in such an installation, the critical
zone 42 could include a data center (not shown), while the utility
zone 44 could include other areas (not shown) of the building, such
as offices, meeting rooms, hallways, manufacturing or processing
rooms, a warehouse, etc. The multi-zone heating-cooling circuit 40
is thermally coupled to the part-load, active, redundant chiller 26
through a circuit feed line 46 for directing the cooling-heating
fluid into the circuit 40 and through a circuit return line 48 for
returning the cooling-heating fluid to one of the absorption
chiller 24 and the part-load, active, redundant chiller 26. The
circuit 40 may also include a circuit pump 49 secured in fluid
communication with the circuit 40, such as with the circuit feed
line 46, to circulate the cooling-heating fluid through the circuit
40. The circuit return line 48 may include an absorption chiller
by-pass valve 50 and an absorption chiller by-pass line 52 secured
in fluid communication between the by-pass valve 50 upstream of the
absorption chiller 24 and the part-load, active, redundant chiller
26, to selectively direct cooling-heating fluid returning from the
cooling-heating circuit 40 around the absorption chiller 24. It may
be desirable for the cooling-heating fluid to bypass the absorption
chiller 24 such as when the chiller 24 is not operating. (For
purposes herein, the word "selectively" is to mean that a
particular component may be controlled or "selected" to perform two
or more functions.)
[0025] The multi-zone cooling-heating circuit 40 also includes a
circuit control valve 54 secured to the circuit feed line 46 and
configured for selectively delivering the cooling-heating fluid
from the part-load, active, redundant chiller 26 to at least one of
the critical zone 42 and the utility zone 44 of the circuit. The
cooling-heating circuit 40 includes a critical zone branch 56 of
the circuit return line 48 for directing flow of the
cooling-heating fluid from the critical zone 42 into the return
line 48. The circuit 40 also includes a utility zone branch 58 of
the circuit return line 48 that similarly serves to direct flow of
the cooling-heating fluid from the utility zone 44 of the circuit
into the circuit return line 48.
[0026] The circuit control valve 54 is secured on the circuit feed
line 46 downstream from the part-load, active, redundant chiller 26
and upstream from the critical zone 42 and the utility zone 44. The
circuit control valve 54 may be a three-way valve, or any valve
means for selectively directing flow of the cooling-heating fluid
from the part-load, active, redundant chiller 26 into at least one
of the critical zone 42 and the utility zone 44. The circuit
control valve 54 may selectively direct flow of all or a portion of
the cooling-heating fluid from the part-load, active, redundant
chiller 26 and the circuit feed line 46 secured thereto through a
critical zone feed line 60 into the critical zone 42 of the circuit
40, or the valve 54 may direct all or some of the cooling-heating
fluid from the circuit feed line 56 through a utility zone feed
line 62 into the utility zone 44 of the circuit 40.
[0027] Similarly, the primary electrical feed line 22 may
selectively direct electricity from the prime mover 12 through a
critical zone electric feed line 64 into the critical zone 42, or
through a utility zone electric feed line 66 into the utility zone
44. For purposes of sound suppression, appearance, efficiency of
installation, etc., the prime mover 12, absorption chiller 24,
part-load, active, redundant chiller 26 and lines and couplings
therebetween may or may not be enclosed within an enclosure 68. An
ARC by-pass line 70 including an ARC by-pass valve 72 may be
secured in fluid communication between the absorption chiller 24,
such as on the ARC thermal feed line 30, and the circuit feed line
46, for selectively directing the cooling-heating fluid to by-pass
the part-load, active, redundant chiller 26. It may be desirable to
by-pass the part-load, active, redundant chiller 24 during times of
low cooling demand, such as in winter months, or to service the
part-load, active, redundant chiller 24.
[0028] A system controller 74 may be secured in communication
through a first communication line 76 secured between the
controller 74 and the absorption chiller 24, and through a second
communication line 78 secured between the controller 74 and the
circuit control valve 54. It is to be understood that the
communication lines 76, 78 may be any means of communication
possible, including wireless transmission of information,
telephone-type lines, electric lines, etc. that are capable of
communicating sensed information and control information.
[0029] Similarly, the system controller 74 may be any controller
means capable of receiving sensed information and controlling the
circuit control valve 54 in response to the sensed information,
including for example a computer secured to the communication lines
76, 78 and a solenoid actuated valve controller (not shown) within
the circuit control valve 54, electro-mechanical linkage between
the absorption chiller 24 and the circuit control valve 54,
manually operated valve control mechanisms in the circuit control
valve 54 actuated by a controller person (not shown) in response to
visually or audibly sensed information about the absorption chiller
24, and any other apparatus capable of performing the described
control of the circuit control valve 54 in response to changes in
operation of the absorption chiller 24. It is also to be understood
that the above-described role of the system controller 74 may be
only a part of the overall capacity of the system controller 74 to
control all described components of the system 10.
[0030] In operation of the cooling, heating and power system 10 of
the present disclosure to satisfy a normal load condition of the
critical zone 42 and the utility zone 44, electricity generated by
the prime mover is directed through the primary electrical line 22
from the prime mover 12 into the utility zone electric feed line 66
and the critical zone electric feed line 64 to satisfy electrical
demands of apparatus within the zones 42, 44, such as computers,
lighting, additional cooling-heating fluid circulating pumps (all
of which are not shown), etc. Electricity also travels through the
electric output 20 of the prime mover 12 into the absorption
chiller 24 and similarly heat travels from the prime mover 12
through the thermal output 18 into the absorption chiller 24.
Electricity is also directed from the prime mover 12 through the
ARC electric feed line 28 into the part-load, active, redundant
chiller 26. The cooling-heating fluid, such as water, circulates
from the circuit return line 48 into the absorption chiller 24 to
be cooled, and then passes through the ARC thermal feed line 30
into the part-load, active, redundant chiller to be further cooled.
The cooling-heating fluid then is directed through the circuit feed
line 36 into the circuit control valve 54 which directs the fluid
into both the critical zone 42 and the utility zone 44. The
cooling-heating fluid then absorbs heat within the zones 42, 44,
and returns through lines 56, 58 into the circuit return line 48 to
be re-cooled within the absorption chiller 24 and part-load,
active, redundant chiller 26, and to be continuously circulated
through the multi-zone cooling-heating circuit 40.
[0031] The part-load, active, redundant chiller is sized to
maintain normal load conditions of the critical zone 42 and utility
zone 44 while operating between about forty percent ("40%") and
about 60%. In the event of a peak load condition, resulting from
example a heat wave in the ambient environment, the part-load,
active, redundant chiller 26 is controlled to increase its output
up to between about 80% and about 100% of its cooling capacity to
satisfy the peak load condition of the critical and utility zones
42, 44. In the event the peak load condition of the critical zone
is not satisfied by increasing the cooling capacity of the
part-load, active, redundant chiller 26 alone, the controller 74
can be utilized to sense such conditions and control the circuit
control valve 54 to increase the amount of cooling-heating fluid
directed to the critical zone 42, while decreasing the amount of
fluid to the utility zone 44.
[0032] The cooling-heating power system 10 can efficiently satisfy
an anticipated offnormal condition, such as an interruption of
operation of the absorption chiller 24. In such an offnormal load
condition, the controller 74 controls the circuit control valve 54
to direct flow of as much of the cooling-heating fluid as is
necessary to satisfy this offnormal load condition of the critical
zone 42. In some circumstances this may be all of cooling-heating
fluid. In the event even all of the cooling-heating fluid does not
satisfy this offnormal load condition of the critical zone 42, the
part-load, active, redundant chiller 26 would be controlled to
increase its cooling output from 40% to 60% capacity to between
about 80% and 100% of its cooling capacity. In such an offnormal
load condition, the absorption chiller by-pass valve 50 may be
controlled to direct flow of the cooling-heating fluid around the
absorption chiller 24 and into the part-load, active, redundant
chiller 26, so that the absorption chiller 24 may be serviced or
replaced, etc. Alternatively, the cooling-heating fluid may simply
continue to flow through the absorption chiller 24 until it returns
to operation.
[0033] Another offnormal load condition would arise if operation of
the prime mover 12 was interrupted. In such a condition, because
the absorption chiller 24 would loose the benefit of the heat from
the prime mover 12 performance of the absorption chiller 24 would
be interrupted. Similarly, the part-load, active, redundant chiller
26 and the absorption chiller 24 would not receive electricity from
the prime mover 12. In such an offnormal load condition, the
electric switch 36 would be closed to direct electricity from the
exterior electricity source 34 into the part-load, active,
redundant chiller 26. The ARC 26 would then continue operation
while the controller 74 would control the circuit control valve 54
to direct as much of the cooling-heating fluid into the critical
zone 42 as is necessary. If greater cooling is required, the ARC 26
would be controlled to increase its cooling capacity to satisfy the
cooling demand of the critical zone 42.
[0034] During below normal load conditions, such as during periods
of time when free cooling is available from ambient environmental
conditions, such as during winter, the ARC by-pass valve 72 may be
controlled to direct flow of the cooling-heating fluid around the
part-load, active, redundant chiller 26 through the ARC by-pass
line 70 into the circuit feed line 46. In such below normal
conditions, the additional cooling capacity of the part-load,
active, redundant chiller 26 may not be necessary.
[0035] An exemplary cooling-heating and power system 10 with an
integrated part-load, active, redundant chiller 26 includes use of
three "PureComfort" System Model PC390M systems integrated
together, which would include the prime mover 12 and the absorption
chiller 24. In such and exemplary system, the prime mover 12 would
include six microturbines and one absorption chiller per
"PureComfort" System Model PC390M. These "PureComfort" Systems are
available from UTC POWER, LLC of South Windsor, Conn., U.S.A.
("PureComfort" is a registered trademark of UTC POWER, LLC.) A
part-load, active, redundant chiller 26 that is a high efficiency
tri-screw electric chiller rated at 420 refrigeration/tons ("RT")
is coupled to the prime mover 12 and the absorption chiller 24 as
described above. The three "PureComfort" System Model PC390M
microturbine systems have a net combined electrical capacity of
1,110 kilowatts ("kW") at standard operating conditions of 15
degrees Celsius ("15.degree. C."). When operating in unison with
the ARC 26 this output is reduced slightly to 1,038 kW because of a
parasitic load of the ARC 26. At standard operating conditions, the
combined cooling output of the described exemplary system is 718
RT. At average summer conditions of 25.degree. C. the system is
expected to produce 975 kW of net power and 897 RT of cooling.
During average winter conditions of around -6.degree. C. the system
is expected to produce 1,110 kW net and a heating capacity in the
form of hot water or steam up to 3,800 pounds per hour.
[0036] Operation of such an exemplary system 10, could be utilized
for the multi-zone cooling-heating circuit 40, wherein the critical
zone 42 has a requirement for 675 kW and a normal cooling load
condition of about 250 RT. Efficient operation of the system 10
would configure the circuit 40 so that the cooling-heating fluid
returns from the critical zone 42 at a temperature about
12.2.degree. C. and at a flow rate of about 2,200 gallons per
minute ("GPM"). The absorption chiller 24 would be configured to
cool the fluid to approximately 9.4.degree. C. The part-load,
active, redundant chiller 26 would be configured to further cool
the fluid to 6.6.degree. C. The circuit pump 49 and circuit control
valve 54 would be configured to deliver the cooled cooling-heating
fluid at 600 GPM to the critical zone 42 and at 1,600 GPM to the
utility zone 44. This would satisfy the aforesaid cooling load
requirement of 250 RT at an extremely efficient energy requirement.
Because the, part-load, active, redundant chiller 26 is configured
to satisfy the cooling load requirement of the critical zone 42
while operating at between about 40% and 60% of the cooling
capacity of the ARC 26, the ARC 26 operates at maximum efficiency
producing the greatest amount of cooling for the least amount of
electrical energy. The exemplary system 10 described above can
deliver cooling to the critical zone 42 and the utility zone 44 at
a range of kilowatts per refrigeration/ton of between about 0.28
kW/RT and about 0.35 kW/RT.
[0037] In selecting and sizing components of the cooling, heating
and power system 10 with an integrated part-load, active, redundant
chiller of the present disclosure, preferably a cooling output of
the system 10 is sized to match a cooling requirement of the
critical zone 42, or any other critical cooling requirement. Design
of the system 10 to meet the cooling load includes sizing and
controlling the absorption chiller 24 to do as much of the cooling
work as possible, "cooling work" meaning reduction in temperature
of the cooling-heating fluid. Typically, the absorption chiller 24
operates at a constant flow, while the ARC chiller 26 operates
efficiently at a variable flow, system control is configured to
balance and optimize the relative flows through the chillers 24,
26.
[0038] As parameters for design of such a system 10 of the present
invention, it is understood that for each 1,000 kW load a typical
total energy supply is about 1,850 kW and would require 350 RT of
cooling. A perfectly sized system 10 would be sized to match the
cooling requirements of the critical zone 42 or any other critical
cooling load. For example, 350 RT equates to, on average, about 250
kW of input electric power through conventional chilling. At 350 RT
cooling production, optimally matched, no matter what prime movers
are involved, the kW electric production will be about 750 kW.
Consequently one can appreciate that the system 10 of the present
disclosure has an enormous value in displaced energy which is
produced at 40-60% of the cost of energy produced by conventional
systems in those geographic areas where electric cost is
sufficiently high in relation to gas cost.
[0039] In the above example, a 750 kW microturbine prime mover 12
would produce about 400 tons nominal absorption cooling. In that
case the electric chilling part-load, active, redundant chiller 26
would be sized at about 400 RT nominal and would therefore be
redundant and available for backup. The ARC 26 would remain in a
run ready state and would be available to come up to full cooling
capacity in about 1 minute, should the absorption chiller 24 cease
operation.
[0040] In the above example, a system 10 utilizing as a prime mover
12 a 750 kW fuel cell 12 would produce only about 100 RT of
absorption cooling. In this case electric chilling part-load,
active, redundant chiller 26 is sized at 400 RT nominal but
continuously runs at part-load state. 100 RT of absorption would be
combined with 250 RT of electric chilling. The system 10 would
include control coordination with load demand, such that the ARC 26
is only producing 250 RT on average. This production is in a highly
efficient central sweet spot of the ARC 26. When operating
independent of absorption, at 250 RT load, the 400 ton part-load,
active, redundant chiller 26 would draw about 0.30 to 0.40 kW per
refrigeration ton to lower the return water to a set point.
Variances in performance would be due to ambient conditions
effecting condenser water temperature. When you utilize the
absorption chiller 24 to pre-cool the cooling-heating fluid, total
cooling inefficiencies will be reduced by 50%.
[0041] With either the microturbine or fuel cell as the prime mover
12 as described above, the absorption chiller 24 is always fully
loaded while the ARC 26 is either dormant or at about half load.
However both chillers 24, 26 can operate at full production. In the
microturbine prime mover 12 example, the total available production
is up to 800 RT nominal. With the fuel cell prime mover 12 based
example, the combined maximum production is up to 500 RT nominal.
In either scenario the absorption chiller 24 is doing part of the
work, which improves the efficiency of the ARC 26. So the increased
amount of cooling is still being produced at kW per ton levels
otherwise unachievable. The improved cooling capacity of the
described system 10 can produce large volumes of chilled water at
kW/RT level as low as 20% to 25% of the amount of input energy
required for equivalent amounts of conventional electric
compression chilling.
[0042] The system 10 further enhances efficiency of operation by
having the system controller 74 control the absorption chiller 24
to utilize a maximum amount of heat utilization from the
recoverable waste generated by the prime mover, while
simultaneously controlling the part-load, active, redundant chiller
26 to operate at maximum efficiency, such as between about 40% and
60% or the maximum cooling capacity of the ARC 26.
[0043] The present disclosure also includes a method of delivering
cooling to the multi-zone cooling-heating circuit 40 having the
critical zone 42 and the adjoining utility zone 44. The method
includes generating electricity and waste heat within the prime
mover 12; directing flow of the generated waste heat into the
absorption chiller 24; directing flow of the generated electricity
into the absorption chiller 24; cooling a cooling-heating fluid
circulating through the multi-zone cooling-heating circuit 40 by
flowing the cooling-heating fluid through the absorption chiller
24; operating the part-load, active, redundant chiller 26 at
between about 40% and about 60% of maximum cooling capacity while
flowing the cooling-heating fluid through the ARC 26 to further
cool the cooling-heating fluid; and, optionally selectively
directing flow of the cooled, circulating cooling-heating fluid
into at least one of the critical zone 42 and the utility zone
44.
[0044] It is to be understood that the cooling, heating and power
system 10 of the present disclosure has been described with respect
to primary features. In actual installation of the system 10 within
a large structure, such as a communications hub for a
telecommunication service provider, additional components would be
included which components would be apparent to one of ordinary
skill in the art. For example, within such a building (not shown),
the multi-zone cooling-heating circuit would also include
additional circulators and pumps for moving air and the
cooling-heating fluid through heat exchangers, controllers such as
thermostats and valves for regulating flow rates of the cooling
heating fluid through heat exchangers, etc.
[0045] While the above disclosure has been presented with respect
to the described and illustrated embodiments of the cooling,
heating and power system 10 with an integrated part-load, active,
redundant chiller 26, it is to be understood that the disclosure is
not to be limited to those alternatives and described embodiments.
Accordingly, reference should be made primarily to the following
claims rather than the forgoing description to determine the scope
of the disclosure.
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