U.S. patent application number 14/513203 was filed with the patent office on 2017-01-12 for multi purpose multistage evaporative cold water and cold air generating and supply system.
This patent application is currently assigned to R4 VENTURES LLC. The applicant listed for this patent is Mikhail Pavlovich Reytblat, Darrell Richardson. Invention is credited to Mikhail Pavlovich Reytblat, Darrell Richardson.
Application Number | 20170010029 14/513203 |
Document ID | / |
Family ID | 56407572 |
Filed Date | 2017-01-12 |
United States Patent
Application |
20170010029 |
Kind Code |
A9 |
Reytblat; Mikhail Pavlovich ;
et al. |
January 12, 2017 |
Multi Purpose Multistage Evaporative Cold Water and Cold Air
Generating and Supply System
Abstract
This discloses apparatuses for industrial or commercial cooling
(or any other cooling) using staged cooling towers to evaporatively
reach temperatures below the wet bulb temperature of the ambient
air. Methods for using such apparatuses are disclosed as well.
Inventors: |
Reytblat; Mikhail Pavlovich;
(Chandler, AZ) ; Richardson; Darrell; (Phoenix,
AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Reytblat; Mikhail Pavlovich
Richardson; Darrell |
Chandler
Phoenix |
AZ
AZ |
US
US |
|
|
Assignee: |
R4 VENTURES LLC
Mesa
AZ
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20160209087 A1 |
July 21, 2016 |
|
|
Family ID: |
56407572 |
Appl. No.: |
14/513203 |
Filed: |
October 13, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13624912 |
Sep 22, 2012 |
8899061 |
|
|
14513203 |
|
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|
61538615 |
Sep 23, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28C 1/08 20130101; F28C
1/14 20130101; F24F 5/0035 20130101; F25B 25/005 20130101; F25B
27/02 20130101; F28C 1/16 20130101; F28C 1/00 20130101; Y02A 30/274
20180101 |
International
Class: |
F25B 25/00 20060101
F25B025/00; F24F 5/00 20060101 F24F005/00; F28C 1/00 20060101
F28C001/00; F25B 19/00 20060101 F25B019/00; F25B 49/00 20060101
F25B049/00 |
Claims
1-20. (canceled)
21. A system comprising: an initial-stage (IS) cooling assembly
that comprises an IS cooling tower having: an ambient air inlet
without an associated heat exchanger, an air outlet, a cooling
fluid reservoir disposed near a bottom of the IS cooling tower; and
a fan dedicated to the IS cooling tower, and configured to move air
through the IS cooling tower; a final-stage (FS) cooling assembly
that comprises a cooling tower having: an air inlet, an air outlet,
a cooling fluid reservoir disposed near a bottom of the FS cooling
tower, a fan dedicated to the FS cooling tower, and configured to
move air first through the FS air-inlet heat exchanger then the FS
cooling tower, a heat exchanger at the air inlet of the FS cooling
tower; and a variable-flow pump that is adapted to pump cooling
fluid through FS supply piping; wherein the IS cooling fluid
reservoir at least connects to a pre-cooling coil of a primary
cooling load and one or more of the following heat exchangers: the
FS air-inlet heat exchanger; and an optional mid-stage (MS)
air-inlet heat exchanger; wherein warmed cooling fluid returns
directly to wet media of the IS cooling tower and to the IS cooling
fluid reservoir for reuse, wherein the FS cooling fluid reservoir
connects to a primary cooling load and optionally one or more
additional cooling loads and warmed cooling fluid returns directly
to wet media of the FS cooling tower and returns to the FS cooling
fluid reservoir for reuse.
22. The system of claim 21 wherein a cooling circuit connects the
FS cooling fluid reservoir, the primary cooling load, and a means
for supplemental cooling (SCM).
23. The system of claim 22 wherein the SCM comprises: thermally
driven adsorption chillers supplying water or water-glycol
solution; thermally driven absorption supplying water or
water-glycol solution; conventional mechanical water chillers;
natural cold fluid sources; river water; sea or ocean water; lake
water; or geothermal water.
24. The system of claim 23 further comprising a computer-based
command-and-control system that is configured to control the
SCM.
25. The system of claim 21 additionally comprising: an MS cooling
assembly that comprises a cooling tower having: an air inlet, an
air outlet, a cooling fluid reservoir disposed near a bottom of the
MS cooling tower, a fan dedicated to the MS cooling tower, and
configured to move air first through the MS air-inlet heat
exchanger then the MS cooling tower, a heat exchanger at the air
inlet of the MS cooling tower, and a pump that is adapted to pump
cooling fluid through MS supply piping; wherein the MS cooling
fluid reservoir connects at least to one or more of the following
heat exchangers: the FS air-inlet heat exchanger; and an MS air
inlet heat exchanger serving the air inlet of another optional MS
cooling tower; and wherein warmed cooling fluid returns directly to
wet media of the MS cooling tower and to the MS cooling fluid
reservoir for reuse.
26. The system of claim 25 wherein the IS cooling tower or the FS
cooling tower is selected from cross-flow or counter-flow cooling
towers.
27. The system of claim 25 wherein the FS cooling fluid reservoir
connects to a final cooling coil of the primary cooling load.
28. The system of claim 27 wherein a cooling circuit connects the
FS cooling fluid reservoir, the primary cooling load, and a means
for supplemental cooling (SCM).
29. The system of claim 28 wherein the circuit additionally
comprises at least one pump or variable-speed pump.
30. The system of claim 29 further comprising a computer-based
command-and-control system that is configured to control the
SCM.
31. The system of claim 30 wherein the computer-based
command-and-control system adjusts an IS variable-speed fan or
variable-speed pump, a MS variable-speed fan or variable-speed
pump, or a FS variable-speed fan or variable-speed pump.
32. The system of claim 31 wherein the computer-based
command-and-control system is adapted to adjust fan speed in
response to a monitored cooling load.
33. The system of claim 32 wherein the computer-based
command-and-control system is adapted to adjust cooling tower pump
speed in response to monitored parameters.
34. The system of claim 33 wherein the computer-based command and
control system is a programmable logic controller.
35. The system of claim 34 wherein the IS cooling tower, the MS
cooling tower, or the FS cooling tower further comprises an energy
recovery system connected to the cooling tower air outlets.
36. The system of claim 35 further comprising: another
liquid-to-liquid heat exchanger positioned between the FS cooling
tower and the primary cooling load or positioned between the IS
cooling tower and the primary cooling load.
37. The system of claim 36 wherein at least the IS cooling fluid
reservoir connects to 2 or more cooling loads; the MS cooling fluid
reservoir connects to 2 or more cooling loads; or the FS cooling
fluid reservoir connects to 2 or more cooling loads.
38. The system of claim 37 wherein the primary cooling load is a
comfort cooling load or a process cooling load.
39. The system of claim 21 further comprising another
liquid-to-liquid heat exchanger: positioned between the FS cooling
tower and the primary cooling load and positioned between the IS
cooling tower and the primary cooling load.
40. The system of claim 21 wherein the primary cooling load is a
comfort cooling load or a process cooling load.
Description
BACKGROUND
[0001] This document introduces a new method and system for a
sustainable . . . high-performance . . . low-energy consumption
combination of direct and indirect evaporative cooling processes
providing maximum cooling at maximum energy efficiency called the
Multistage Evaporative Cooling System (MECS). The method and system
of the MECS uses a water-into-ambient-air evaporation process.
[0002] Water evaporation processes for a variety of comfort and
process-cooling needs have existed for many centuries. The most
current representative applications of evaporative cooling are the
home evaporative air coolers (swamp coolers) and commercial and
industrial cooling towers. The cooling apparatuses are relatively
simple in design and operation, and they evaporate water directly
into ambient air from different types of wet media, which usually
have large surface areas. Physics limits the temperature that these
cooling apparatuses can achieve when cooling air or water. The wet
bulb temperature of the ambient air and the cooling system's design
primarily govern the cooling apparatus's low-temperature limit. But
regardless of the design of these single stage evaporative cooling
apparatuses, the wet bulb temperature of the ambient air is the
theoretical absolute low limit for the achievable final temperature
of the cooled media (air or water). In other words, under no
circumstances can the final temperature of the cooled media for the
above apparatuses achieve a value equal to or lower than the
ambient air's wet bulb temperature: there will always be some
difference between the wet bulb temperature of the ambient air and
cold air or water from the apparatus. This temperature difference
is defined as an "approach temperature". The approach temperature
value varies greatly depending on the cooling apparatus's design.
The temperature of the cold air or cold water from the adiabatic
cooling apparatus will always be higher than the wet bulb
temperature of the entering air being cooled by the apparatus. In
other words, the approach temperature of the adiabatic cooling
apparatus equals the temperature of the cold water produced by the
apparatus minus the wet bulb temperature of the entering air. For
general applications of these cooling apparatus, the approach
temperature is within a range of 5 to 10.degree. F.
[0003] The design of invention embodiments arises from applying
engineering principals to discover component arrangements and
sequencing of components that result in the ambient air wet bulb
temperature barrier being lowered.
[0004] Another way of stating the above is as follows. In
traditional single-stage direct evaporative cooling, the
evaporative cooling process lowers the dry bulb temperature of the
processed air (ambient air or a mixture of ambient air and return
air), while the wet bulb temperature and enthalpy of the processed
air are not changed--they are equal to their initial values. In the
single-stage direct evaporative cooling process, the initial wet
bulb temperature of the adiabatically processed air is the absolute
theoretical temperature limit for the dry bulb temperature of the
adiabatically cooled processed air. As stated above, the difference
between the dry bulb temperature of the adiabatically cooled air
and its wet bulb temperature is known as the "approach
temperature".
[0005] This principal establishes the following: the lower the
approach temperature the higher the efficiency of the adiabatic
cooling process. The single stage direct evaporative cooling
system/unit is not capable of achieving required temperature levels
of cooling media (air or water) that is appropriate for practical
use in a majority of demanding cooling applications.
[0006] Therefore, there is a strong need for the creation of new
universal methods and systems allowing maximum utilization of the
laws of thermodynamics related to evaporative cooling applications
providing effective and energy efficient evaporative cooling
systems for a wide variety of applications by using methods
incorporating multiple stages of evaporative cooling.
SUMMARY
[0007] The Inventor has developed new methods and systems that
provide evaporative cooling by combining multiple direct and
indirect evaporative cooling stages into one multistage evaporative
cooling system to achieve cooling media (air or water) temperatures
that are much lower than the initial wet bulb temperature of the
ambient air. The Inventor has named this cooling system the
Multistage Evaporative Cooling System (MECS: sometimes referred to
simply as a cooling system). This new approach and method of the
combined multiple direct and indirect evaporative cooling processes
fully complies with all laws of thermodynamics by properly
sequencing components and actions to achieve maximum cooling at a
minimal energy use. The MECS outperforms conventional refrigeration
systems by using at least 50% less energy to operate. The MECS's
resulting output is cold air, cold water, or both. For some
critical cooling applications (for instance, cooling of large
volumes of makeup air) at low or moderate ambient air humidity
levels, MECS significantly outperforms comparable Conventional
Mechanical Refrigeration Systems.
[0008] Invention embodiments are drawn to cooling systems with at
least two stages. The first-stage cooling assembly includes a
forced-draft cooling tower with an air inlet, an air outlet, a cold
water reservoir, a variable speed fan, and a variable flow water
pump that is adapted to pump cold water through first-stage supply
piping. The final-stage cooling assembly includes a forced-draft
cooling tower with an air inlet, an air outlet, a cold water
reservoir, a variable speed fan, an air-to-water heat exchanger at
the air inlet of the final-stage cooling tower and a variable flow
water pump that is adapted to pump cold water through final-stage
supply piping. This assembly is connected so that cold water
produced from operating the first stage can be pumped to a heat
exchanger on the final stage (or in some embodiments, another
stage) and/or some other cooling load. The heat exchanger cools
ambient air as it enters the final stage cooling tower. Ultimately,
since the final stage cooling tower operates with air that is
colder than the ambient air used by the cooling tower in the first
stage, the final stage cooling tower can produce water that is
colder than the wet bulb temperature of the ambient air. Various
embodiments comprise command and control systems to operate the
mechanical components of the cooling system to avoid operating at
over capacity or any other operating regime that wastes energy.
[0009] Some embodiments include one or more additionally
intermediate-stage cooling assemblies that comprises a forced-draft
cooling tower with an air inlet, an air outlet, a cold water
reservoir, a variable speed fan, an air-to-water heat exchanger at
the air inlet of the intermediate-stage cooling tower and a
variable flow water pump that is adapted to pump cold water through
intermediate-stage supply piping.
[0010] Operation of three or more stages has cold water from the
first stage cooling air entering an intermediate stage with the
final stage air-to-water heat exchangers being fed from one or more
intermediate stages allowing even lower cold water temperatures to
be reached.
[0011] In some embodiments, any of the cooling towers may direct
all or some of their cold exhaust air exiting the cooling tower
through an energy recovery system that uses an air-to-water heat
exchanger and the cold air to create a cold water supply for
additional cooling wherever such cooling is needed. The energy
recover system is typically operated as a closed loop system.
[0012] In some embodiments, the final stage is used to cool various
cooling loads such as process cooling loads or cools the make up
air flowing through the make up air handling unit for supplying
cold air to the building.
[0013] Some method embodiments include steps of supplying the
cooling stages described above and operating the cooling stages so
that the final cooling stage or one or more of the intermediate
cooling stages produce cold water with a temperature below the
ambient wet bulb temperature of the air used in the cooling
process.
[0014] In some embodiments, the energy recovery system includes an
air inlet adapted to receive cool air from a cool air source, an
air-to-water heat exchanger, a fan, a pump, piping connecting from
the air-to-water heat exchanger to a cooling load then to the pump
and then back to the air-to-water heat exchanger or from the
air-to-water heat exchanger to the pump and then to a cooling load
and then back to the air-to-water heat exchanger. The energy
recovery system uses waste cool air exhaust from a cooling tower in
some embodiments.
FIGURES
[0015] FIG. 1 depicts a cooling tower useful in invention cooling
system embodiments.
[0016] FIG. 2 depicts another useful cooling tower further
comprising an air-to-water heat exhanger or an air pre-cooling heat
exchanger.
[0017] FIG. 3 depicts another useful cooling tower further
comprising an energy recovery system.
[0018] FIG. 4 depicts a cooling system embodiment of the
invention.
[0019] FIG. 5 depicts another cooling system embodiment of the
invention.
[0020] FIG. 6 depicts another cooling system embodiment of the
invention.
[0021] FIG. 7 depicts a makeup air handling unit.
[0022] FIG. 8 depicts an energy recovery system, such as seen in
FIG. 3.
[0023] FIG. 9 is a diagram of another MECS embodiment.
[0024] FIG. 10 is a diagram of another MECS embodiment with
supplemental cooling module.
[0025] FIG. 11 is a diagram of another MECS embodiment with a
closed-loop cooling tower.
[0026] FIG. 12 is a diagram of an ISECS embodiment.
[0027] FIG. 13 is a diagram of an ISECS embodiment with a
supplemental cooling module.
[0028] FIG. 14 is a diagram of another ISECS embodiment with a
supplemental cooling module.
[0029] FIG. 15 is a diagram of an ISECS with a third cooling
coil.
DETAILED DESCRIPTION
[0030] The following description of several embodiments describes
non-limiting examples that further illustrate the invention. No
titles of sections contained herein, including those appearing
above, are limitations on the invention, but rather they are
provided to structure the illustrative description of the invention
that is provided by the specification.
[0031] Unless defined otherwise, all technical and scientific terms
used in this document have the same meanings that one skilled in
the art to which the disclosed invention pertains would ascribe to
them. The singular forms "a", "an", and "the" include plural
referents unless the context clearly indicates otherwise. Thus, for
example, reference to "fluid" refers to one or more fluids, such as
two or more fluids, three or more fluids, etc. Any mention of an
element includes that element's equivalents as known to those
skilled in the art.
[0032] Any methods and materials similar or equivalent to those
described in this document can be used in the practice or testing
of the present invention. This disclosure incorporates by reference
all publications mentioned in this disclosure and all of the
information disclosed in the publications.
[0033] This disclosure discusses publications only to facilitate
describing the current invention. Their inclusion in this document
is not an admission that they are effective prior art to this
invention, nor does it indicate that their dates of publication or
effectiveness are as printed on the document.
[0034] The features, aspects, and advantages of the invention will
become more apparent from the following detailed description,
appended claims, and accompanying drawings.
Exemplary Features of the MECS
[0035] The MECS's new methods and systems allows the generation of
supply air or cooling fluid, such as water, at a low temperature,
meeting the conditioned space's temperature control requirements
without adding moisture to the supply air or fluid in most cases.
[0036] Design Simplicity (MECS does not need to rely on any
high-energy-using refrigeration compressors). [0037] Ecologically
sound design (MECS uses only water and atmospheric air-no need to
use Freon-type refrigerants such as hydrochlorofluorocarbons
(HCFCs)). [0038] Scalability (MECS can be scaled to provide as
little as 5 tons to well over 500 tons of equivalent Conventional
Mechanical Refrigeration Cooling). [0039] Economical Energy Use
(MECS has significantly lower power consumption compared to
Conventional Mechanical Refrigeration Systems). [0040] Green
Electrical Energy Use (MECS can use green electrical energy sources
(solar, wind, etc.).
[0041] FIG. 1 shows cooling tower 10, a Type-I cooling tower.
Cooling tower 10 comprises tower casing 15, cold-water reservoir
20, air inlet 35, air outlet 40, water distribution system with
nozzles 51, fan 55, pump 60, cold water outlet 65, warm water inlet
66, and mist eliminator 71. Fan 55 is not present in some
embodiments. Air inlet 35 sits near the bottom of cooling tower 10
in the embodiment depicted by FIG. 1. Other embodiments can be
envisioned in which air inlet 35 sits remotely from cooling tower
10, but in those embodiments, ambient air should enter cooling
tower 10 below air outlet 40. Cold-water reservoir 20 sits near the
bottom of cooling tower 10. But other embodiments exist in which
cold-water reservoir 20 sits remotely from cooling tower 10. In
those types of embodiments, one of ordinary skill in the art would
recognize that additional piping and plumbing would be useful in
such embodiments.
[0042] In some embodiments, airflow through cooling tower 10 is
assisted by fan 55. Fan 55 sits near the uppermost part of cooling
tower 10 near air outlet 40. Fan 55 may either be located
downstream of mist eliminator 71 or upstream of mist eliminator 71.
Alternatively, a fan may mount at the inlet of cooling tower 10,
pushing ambient air through cooling tower 10. Of course, a cooling
tower could use two or more fans.
[0043] In some embodiments, water is distributed by the water
distribution system with nozzles 51 over a mass heat transfer media
(fill). In these types of embodiments, one of ordinary skill in the
art would recognize that mass heat transfer occurs through the
interaction between the water and air on the surface of the
fill.
[0044] As stated previously, FIG. 1 depicts fan 55 on the top of
cooling tower 10. Mist eliminator 71 sits near the top of cooling
tower 10 in the embodiment depicted in FIG. 1, as will be the case
in most embodiments that employ a counter flow design. Some
embodiments may use a cross flow cooling tower design, which would
lead to a different arrangement of air inlets, water distribution
systems, fans, etc. Water distribution system with nozzles 51
attaches to warm water inlet 66, which connects between cooling
load 11 at the warm water outlet of air-to-water heat exchanger 230
and water distribution system with nozzles 51. Pump 60 connects to
cold-water reservoir 20 and connects to cooling loads 11 and an
external air-to-water heat exchanger, such as air-to-water heat
exchanger 230, through cold water outlet 65. Cold water outlet 65
also connects to the cold water inlet of air-to-water heat
exchanger 230.
[0045] Invention cooling systems use a variety of cooling towers in
addition to cooling tower 10.
[0046] FIG. 2 shows another type of cooling tower used in invention
cooling systems--cooling tower 210, a Type-II cooling tower.
Cooling tower 210 comprises tower casing 15', cold-water reservoir
20', air inlet 35', air outlet 40', water distribution system with
nozzles 51', fan 55', pump 60', cold water outlet 65', warm water
inlet 66', mist eliminator 71', and air-to-water heat exchanger
230.
[0047] Air-to-water heat exchanger 230 comprises a housing 231,
heat exchanger cold water inlet 213, and heat exchanger warm water
outlet 214. In some embodiments, heat exchanger cold water inlet
213 connects to cold water outlet 65 and heat exchanger warm water
outlet 214 connects to warm water inlet 66 of a Type-I cooling
tower. In other embodiments, heat exchanger cold water inlet 213
connects to cold water outlet 65' and heat exchanger warm water
outlet 214 connects to warm water inlet 66' of a Type-II cooling
tower.
[0048] Air inlet 35' sits near the bottom of cooling tower 210, in
the embodiment depicted by FIG. 2. Other embodiments exist in which
air inlet 35' sits remotely from cooling tower 210 as long as
ambient air enters cooling tower 210 below air outlet 40'.
Air-to-water heat exchanger 230 sits between air inlet 35' and
cooling tower 210. Cold-water reservoir 20' sits near the bottom of
cooling tower 210. But other embodiments exist in which cold-water
reservoir 20' sits remotely from cooling tower 210. In those types
of embodiments, one of ordinary skill in the art would recognize
that additional piping and plumbing would be useful.
[0049] In some embodiments, fan 55' assists air in flowing through
cooling tower 210. Fan 55' sits on the top of cooling tower 210
near air outlet 40'. Fan 55' may sit either downstream of mist
eliminator 71' or upstream of mist eliminator 71'. Alternatively, a
fan mounts at the inlet of cooling tower 210, designed to push
ambient air through cooling tower 210. Of course, this cooling
tower may use two or more fans.
[0050] In some embodiments, water is distributed by the water
distribution system with nozzles 51 over a mass heat transfer media
(fill). In these types of embodiments, one of ordinary skill in the
art would recognize the mass heat transfer interaction between the
water and air on the surface of the fill.
[0051] Pump 60' is in fluid communication with cold-water reservoir
20' and in fluid communication with water distribution system with
nozzles 51', which is located near the uppermost part of cooling
tower 210. In some embodiments, "fluid communication" encompasses a
cold water outlet 65' connected to pump 60'. Cold water outlet 65'
connects through an external device, comprising a pipe, heat
exchanger, or other external device (such as cooling load 11'), to
warm water inlet 66'. In these or other embodiments, pump 60'
connects to cold-water reservoir 20' and connects to cooling loads
11' and an external air-to-water heat exchanger, such as
air-to-water heat exchanger 230', through cold water outlet 65'.
Warm water inlet 66' connects to water distribution system with
nozzles 51'. In some embodiments, cold water outlet 65' connects to
an external device such as an air-to-water heat exchanger mounted
upon another or an adjacent cooling tower or a cooling tower of
another cooling stage, and then continues on to water distribution
system with nozzles 51' through warm water inlet 66'.
[0052] In some embodiments, pump 60' services water distribution
system with nozzles 51'. In these or other embodiments, pump 60' or
another pump pumps cold water from cold-water reservoir 20' to the
cold water inlet on an air-to-water heat exchanger mounted on
another cooling tower and another pump pumps water to water
distribution system with nozzles 51'.
[0053] FIG. 3 shows another type of cooling tower for use in
invention cooling systems--Cooling tower 310, a Type-III cooling
tower. Cooling tower 310 comprises tower casing 15'', cold-water
reservoir 20'', air inlet 35'', air outlet 40'', water distribution
system with nozzles 51'', fan 55'', pump 60'', pipe 65'', mist
eliminator 71'', air-to-water heat exchanger 230', and energy
recovery system 330.
[0054] Air-to-water heat exchanger 230' comprises a housing 231',
heat exchanger cold water inlet 213', and heat exchanger warm water
outlet 214'.
[0055] Air inlet 35'' sits near the bottom of cooling tower 310 in
the embodiment depicted by FIG. 3. Other embodiments exist in which
air inlet 35'' sits remotely from cooling tower 310 as long as
ambient air enters cooling tower 310 below air outlet 40''.
Air-to-water heat exchanger 230' sits between air inlet 35'' and
cooling tower 310. Cold-water reservoir 20'' sits near the bottom
of cooling tower 310. But other embodiments exist in which
cold-water reservoir 20'' sits remotely from cooling tower 310. In
those types of embodiments, one of ordinary skill in the art would
recognize that additional piping and plumbing would be useful in
such embodiments. As in cooling tower 210, various embodiments
exist in which cold-water reservoir 20 and cold-water reservoir 20'
are located remotely from cooling tower 10 and cooling tower 210,
respectively.
[0056] In some embodiments, fan 55'' assists air in flowing through
cooling tower 310. Fan 55'' sits on the top of cooling tower 310
near air outlet 40''. Fan 55'' may sit downstream of mist
eliminator 71'' or upstream of mist eliminator 71''. Alternatively,
a fan mounts at the inlet of cooling tower 310, designed to push
ambient air through cooling tower 310. Of course, a cooling tower
may use two or more fans.
[0057] In some embodiments, water is distributed by the water
distribution system with nozzles 51'' over a mass heat transfer
media (fill). In these types of embodiments, one of ordinary skill
in the art would recognize that the mass heat transfer interaction
between the water and air on the surface of the fill.
[0058] Pump 60'' is in fluid communication with cold-water
reservoir 20'' and in fluid communication with water distribution
system with nozzles 51'' located near the uppermost part of cooling
tower 310. In some embodiments, fluid communication encompasses a
pipe 65'', connected between pump 60'' and water distribution
system with nozzles 51''.
[0059] In some embodiments, pump 60'' services water distribution
system with nozzles 51''. In these or other embodiments, pump 60''
or another pump pumps cold water from cold-water reservoir 20'' to
a cooling load (such as cooling loads 11'' or a makeup air handling
unit 715). Invention embodiments may cool any suitable cooling load
(cooling loads 11''). Suitable cooling loads can be virtually any
cooling load and include the following cool loads: environmental
cooling (HVAC), building comfort cooling, process cooling,
individual server enclosure/rack cooling, or any electronics
enclosure generating a heat load. In some embodiments, the cooling
load is a make up air handling unit (MU Air Handling Unit or
MUAHU). In some embodiments, any cooling load that can be cooled
with one or more cooling coils is suitable for this invention.
[0060] In some embodiments, such as the embodiment depicted in FIG.
8, energy recovery systems, such as energy recovery systems (ERS)
330 comprise a water circulation system comprising a pump 860 and
an air-to-water heat exchanger 830. A particulate filter 831 sits
upstream of air-to-water heat exchanger 830, between an associated
cooling tower and air-to-water heat exchanger 830. After
air-to-water heat exchanger 830 comes fan 835 and finally exhaust
air outlet 836 to atmospheric air. ERS 330 connects to any suitable
cooling load 811 through a closed-loop water circulation system.
The water circulation system comprises air-to-water heat exchanger
830, warm water inlet pipe 866, pump 860, cooling load 811, and
cold water outlet pipe 865. Beginning with air-to-water heat
exchanger 830, cold water outlet pipe 865 connects to the output of
air-to-water heat exchanger 830 and connects to the cold water
inlet of cooling load 811. The warm water outlet of cooling load
811 connects to pump 860. Pump 860 connects to warm water inlet
pipe 866, which in turn connects to the warm water inlet of
air-to-water heat exchanger 830. ERS 330 recovers "coolness" from
the cool air exhaust stream of an associated cooling tower. Since
this is a closed loop fluid circulating system, the water can be
any suitable heat transfer fluid including a water and glycol
mixture.
[0061] In some embodiments, energy recovery system 330 operates in
conjunction with dampers 340, 341 in an associated cooling tower.
Damper 340 sits in the air outlet pathway and damper 341 sits in
the ERS air pathway. Both are disposed to allow the air flow to be
adjusted from 100% through air outlet 40'' and 0% through ERS 330,
0% air outlet 40'' to 100% through ERS 330, or any combination of
air flows. Any of the cooling tower examples described in this
document may additionally comprise an energy recovery system
located at the air outlet of the cooling tower.
[0062] In any of the cooling tower types, one or more pumps may be
variable speed pumps or fixed speed pumps. In any of the cooling
tower types, one or more fans may be fixed speed fans or variable
speed fans.
[0063] In addition to the components discussed above, the cooling
towers comprise monitoring and command-and-control hardware and
optionally software, to monitor and control the operation of the
cooling towers. Various types of monitoring and command-and-control
hardware and software are familiar to those of ordinary skill in
the art. For instance, variable speed fans have command-and-control
hardware and software that operate to vary the speed of fans to
control airflow through the cooling towers. Variable speed pumps
have command-and-control hardware and software to control the flow
rate of cold water from cold-water reservoir through the various
other components of the cooling tower and to cooling loads. Control
over such components is based on the cooling needs of the cooling
load, outside temperatures, etc. Control is exercised in some
embodiments to only run necessary fans, pumps, etc. to meet the
necessary cooling load without wasting energy. One category of
energy that is saved because of the intervening command and control
systems, is energy normally wasted by operating fans, pumps, etc.
faster or at a higher capacity than necessary to satisfy the
cooling load demands on the cooling system. In some embodiments,
components of the MECS are operated by a dedicated control system
communicating with a building energy management system. The control
software of the control system optimizes the operation of the
cooling system components to meet variable or constant conditioned
space cooling loads, process cooling loads, or other cooling loads
at the absolute lowest or minimum amount of energy consumption.
[0064] FIG. 4 depicts an embodiment of an invention cooling system.
Cooling system 400 comprises three cooling towers: a Type-I cooling
tower, cooling tower 401; a Type-II cooling tower, cooling tower
402; and a Type-III cooling tower, cooling tower 403. Cold-water
reservoir 20 of cooling tower 401 connects through cold water
outlet 65 to heat exchanger cold water inlet 213, which connects to
air-to-water heat exchanger 230 of cooling tower 402. Air-to-water
heat exchanger 230 of cooling tower 402 connects through heat
exchanger warm water outlet 214 to warm water inlet 66, which
returns warm water to cooling tower 401, as shown in the figure. In
some embodiments, warm water returns to the water distribution
system with nozzles 51 of cooling tower 401.
[0065] Cold-water reservoir 20' of cooling tower 402 connects
through cold water outlet 65' to heat exchanger cold water inlet
213' of air-to-water heat exchanger 230' of cooling tower 403.
Air-to-water heat exchanger 230' connects through heat exchanger
warm water outlet 214', to warm water inlet 66', which returns warm
water to cooling tower 402, as shown in FIG. 4. In some
embodiments, warm water returns to the water distribution system
with nozzles 51' of cooling tower 402.
[0066] Cold-water reservoir 20'' of cooling tower 403 has cold
water outlet 65'' that connects to the cold water inlet of any
suitable cooling load 11''. Likewise, warm-water returns through
warm water inlet 66'' connecting the warm water outlet of cooling
load 11'' to the water distribution system with nozzles 51'' of
cooling tower 403.
[0067] Cold-water reservoir 20 of cooling tower 401 and cold-water
reservoir 20' of cooling tower 402 may connect to optional
cold-water supply and warm-water return lines connecting to various
different cooling loads 11, 11'. One of ordinary skill in the art
would choose which cold-water reservoir (which cooling stage) to
use based on the nature of the cooling load. In some embodiments,
the cooling system comprises four or more cooling towers.
[0068] FIG. 5 depicts cooling system 500, which is similar to
cooling system 400 of FIG. 4, discussed above. In addition to the
components and connectivity discussed for the cooling system above,
this cooling system contains at least one energy recovery system
330 wherein the energy recovery system 330 attaches to one or more
cooling towers such as cooling towers 501, 502, 503 to recapture
the "coolness" of cold air exiting from the cooling tower. In some
embodiments, cooling system 500 comprises a second or third energy
recovery system 330, 330' on the second or third cooling towers,
such as cooling tower 502 or cooling tower 503. And in some
embodiments, the cooling system comprises four or more cooling
stages with an energy recovery system on one or more cooling
towers.
[0069] One typical, suitable cooling load for a cooling system such
as cooling system 400 or 500 is a Make Up Air Handling Unit
(MUAHU).
[0070] Makeup Air Handling Unit 715 comprises one or more air
particulate filters 750 at or near air inlet 720 of MUAHU 715.
Following the air path through MUAHU 715, air-to-air heat exchanger
745 is downstream of air inlet 720 and air particulate filters 750.
Air-to-air heat exchanger 745 comprises two air paths that do not
mix with each other. One of those air paths relates to the make up
air and the other relates to the building exhaust air. Fan 755
pulls building exhaust air through air-to-air heat exchanger 745,
and fan 735 pulls make up air through air-to-air heat exchanger
745. An air-to-water heat exchanger 740 comes after air-to-air heat
exchanger 745 in MUAHU 715. A variable or fixed speed supply fan
735 is disposed in MUAHU 715 downstream of air-to-water heat
exchanger 740. In some embodiments, a high pressure water fog
humidifier 732 (or other types of direct adiabatic humidifiers) is
disposed in MUAHU 715 downstream of variable or fixed speed supply
fan 735. In some embodiments, a mist eliminator 730 sits near air
outlet 731 of MUAHU 715 downstream of the humidifier 732. Cold
water outlet 65'' transports cold water from a cooling system to
the cold water inlet of air-to-water heat exchanger 740. Warm water
inlet 66'' transports warm water from the warm water outlet of
air-to-water heat exchanger 740 back to the cooling system.
[0071] In some embodiments, components of the MECS are operated by
a dedicated control system communicating with a building energy
management system. The control software of the control system
optimizes the operation of the cooling system components to meet
variable or constant conditioned space cooling loads, process
cooling loads, or other cooling loads at the absolute lowest or
minimum amount of energy consumption. Executing this software, the
control system, depending on the conditioned space load, the
process cooling load, or some other cooling load and indoor and
outdoor air dry bulb and wet bulb temperatures, automatically
provides the necessary speed control over cooling towers fans,
supply air fans of makeup air-handling units, return and supply air
fans, return and supply air humidifiers, etc., and the necessary
flow control over the cooling fluids by controlling pumps, which
are typical components of commercial, industrial, or other cooling
systems. The control system also automatically adjusts all
operational components of the MECS to achieve the amount of cooling
needed for the load in real time to maximum cooling efficiency.
[0072] In some embodiments, determined by the cooling application
and the environmental conditions of the specific geographical area,
components of the MECS are rearranged in an order and sequence and
properly sized to maximize the generation of cold water for given
environments. These cooling applications or any kind of cooling
application in commercial real estate buildings, industrial real
estate buildings, and government real estate buildings;
manufacturing plants; industrial processing plants; food/beverage
processing plants and agricultural buildings.
[0073] In some embodiments, an individual electronics enclosure
cooling system uses cold water generated by the different stages of
the MECS to apply process cooling method to each cooling load in
each individual electronics enclosure. In some embodiments,
invention cooling systems are optimized for providing cold water to
individual electronic enclosures or racks, such as server racks to
cool the loads. The electronics enclosure is designed to allow
space air to be drawn in to cool the electronics equipment inside
the enclosure through an air inlet and further pulled through the
enclosure to an air outlet exit point. The warm air, which was
heated by the electronics within the enclosure, exits the air
outlet of the enclosure and enters into an air inlet of one or more
fan coils units. There the warm air is cooled by circulating
cooling water such as from an invention cooling system, i.e. cold
water from different stages of the MECS, before the cooled air is
returned to the space from the air outlet of the fan coil unit.
[0074] Cooling system embodiments exist comprising 2-10, 2-5, 5, 4,
3, or 2 types of cooling towers or cooling tower cells. Each of
these embodiments comprises 0, 1, or 2 energy recovery system per
cooling tower.
Operation of MECS System
[0075] Operationally, any cooling tower suitable for use with the
cooling systems of the current invention operates as described
below. A cooling tower cools incoming ambient air and water from
the cold-water reservoir 20. Fan 55 assists in moving air through
the cooling tower. Ambient air enters the cooling tower through air
inlet 35 and exits the cooling tower at the top through air outlet
40. As the fan pulls air into the cooling tower, water distribution
system with nozzles 51 introduces water on top of the fill through
water distribution system nozzles 51 causing or allowing contact
between the moving ambient air and the falling liquid water within
the fill. The cooled falling liquid water is collected in the
cold-water reservoir 20 and the saturated cold air exits the
cooling tower through air outlet 40.
[0076] Pump 60 pumps water from cold-water reservoir 20 through
cold water outlet 65 to a cooling load, such as air-to-water heat
exchanger 230. After moving through the cooling load, the now
warmer, cold water travels through warm water inlet 66 into water
distribution system with nozzles 51 located above the fill of
cooling tower 10. Water falling from the top of cooling tower 10
passes by ambient air moving from air inlet 35 at the bottom of
cooling tower 10 to air outlet 40 at the top of cooling tower 10.
Fan 55 moves air through cooling tower 10.
[0077] This air-water interaction causes some water to evaporate.
Water evaporation requires energy, in this case, the energy is
extracted from the water flowing through the fill, leaving the
water at a lower temperature and the air exiting air outlet 40 at
DB temperature lower than ambient air temperature. That is, the
air-water interaction lowers the temperature of the air as the air
passes through the cooling tower. Cold water falls to the bottom of
cooling tower 10 and collects in cold-water reservoir 20.
[0078] All psychometric parameters of the given air have direct
correlation with each other in any kind of cooling apparatus.
Knowing the dry bulb temperature, the wet bulb temperature, and the
barometric pressure of the air allows the determination of all
other parameters of the air such as enthalpy, relative humidity,
dew point temperature, absolute moisture content, specific volume,
etc. For a particular sample of air, the maximum wet bulb
temperature is equal to the dry bulb temperature. Larger
differences between the dry bulb temperature and the wet bulb
temperature indicate drier air.
[0079] One of ordinary skill in the art knows that adiabatic
cooling of a particular sample of ambient air equal to or below its
wet bulb temperature is not possible. During the adiabatic air
cooling process, the air's dry bulb temperature is lowered and its
moisture content is increased, however, its wet bulb temperature
and enthalpy do not change. This has ramifications in using
evaporative cooling towers.
[0080] Cold-water reservoir 20 located near the bottom of cooling
tower 401 feeds cooling loads 11. The warm water from cooling load
11 connects to warm water inlet 66, and to water distribution
system with nozzles 51 of cooling tower 401 completing the cycle.
Gravity causes the water to fall through the cooling tower fill
back into the cold-water reservoir. During this trip, the water
again interacts with the air flowing up through the cooling tower
and is in direct contact with the air flowing through the cooling
tower. The main result from this air-water contact is that, as
before, some amount of the water evaporates in the air flowing up
through the cooling tower. And the cycle continues.
[0081] The difference between the dry bulb temperature and the wet
bulb temperature is smaller after passing through the cooling
tower. Therefore, one of ordinary skill in the art recognizes that
the trip through the cooling tower lowers the temperature of the
water.
[0082] Each of the multiplicity of invention cooling towers
operates in this manner. The temperature of the cold water
generated by any cooling tower is dependent on the wet bulb
temperature of the air entering the cooling tower. The cooling
towers use ambient air during operation. Therefore, the only way of
attaining cold water temperatures lower than the wet bulb
temperature of the ambient air, is to lower the wet bulb and dry
bulb temperatures of the ambient air entering the cooling tower. In
other words, sensible pre-cooling of the ambient air entering the
cooling tower reduces its wet bulb and dry bulb temperature thereby
allowing colder water temperatures to be achieved at each cooling
stage.
[0083] The Type-II cooling towers and Type-III cooling towers add
sensible pre-cooling of the ambient air entering the cooling towers
through an air-to-water heat exchanger at their air inlets. These
air-to-water heat exchangers, also called pre-cooling heat
exchangers sit between their respective air inlet and respective
cooling tower. A cold-water reservoir of another stage of the
cooling system or of a previous stage of the cooling system
provides cold water for the air-to-water heat exchanger. As ambient
air passes through the heat exchanger, it cools and water from the
cold-water reservoir warms. The water returns to the source cooling
tower water distribution system with nozzles 51 continuing the
cycle. The source cooling tower ultimately removes the heat gained
by the cold water as it passed through the air-to-water heat
exchanger.
[0084] The ambient air passes through the air-to-water heat
exchangers which lowers the wet bulb and dry bulb temperatures of
the air entering the Type-II or Type-III cooling towers. Since the
wet bulb temperature serves as the lower limit for the temperature
of the cold-water in this cooling towers and since the wet bulb
temperature of the pre-cooled air is lower than that of the
incoming ambient air in a previous cooling stage, the Type-II or
Type-III cooling tower produces cold water with a temperature lower
than cold water produced by an earlier cooling stage. This ability
of a later cooling stage to produce colder water than an earlier
cooling stage stems directly from the fact that the sensible
pre-cooling of ambient air without exposing it to added moisture
simultaneously drops the air's dry bulb and wet bulb temperatures.
Dropping the wet bulb temperature of each stage's air entering the
cooling towers lowers the temperature of the cold water produced by
these stages. Thus, cascading cooling towers allows the cooling
system to produce lower temperature cold water in each of the
successive stages.
[0085] Returning to FIG. 4, the cooling system functions to produce
cold water to service cooling loads 11, 11', 11'', and the cooling
load resulting from MU Air Handling Unit 715. In cooling tower 401,
fan 55 operates to pull air ambient air through air inlet 35,
through air-to-water heat exchanger 230, through the wet fill, past
the water distribution system with nozzles 51, through the mist
eliminator 71, up through the fan 55, and finally out air outlet
40. Simultaneously with air moving up through the cooling tower
401, pump 60 pumps cold water from cold-water reservoir 20, through
cold water outlet 65, connected to heat exchanger cold water inlet
water pipe 213, through air-to-water heat exchanger 230 on cooling
tower 402, out air-to-water heat exchanger 230, through heat
exchanger warm water outlet water pipe 214 connected to warm water
inlet 66, and, completing the cycle, to water distribution system
with nozzles 51 of cooling tower 401. Water distribution system
with nozzles 51 distributes water evenly across the top of the fill
of cooling tower 401. The water falls by gravity through the fill
of cooling tower 401 to cold-water reservoir 20. As cold water from
cold-water reservoir 20 moves through the system, it provides a
source of indirect sensible pre-cooling for air entering cooling
tower 402 through air-to-water heat exchanger 230. The warmed water
is returned to cooling tower 401 via the water distribution system
with nozzles 51.
[0086] Fan 55' of cooling tower 402 operates to pull ambient air
into cooling tower 402 through air inlet 35', through air-to-water
heat exchanger 230, through the wet fill, past the water
distribution system with nozzles 51, through the mist eliminator
71, up through fan 55', and finally out air outlet 40' of cooling
tower 402. Water from water distribution system with nozzles 51'
distributes water evenly across the top of the fill of cooling
tower 402. As the water falls by gravity through the fill of
cooling tower 402, it interacts with the moving pre-cooled air
stream that has been pre-cooled by air-to-water heat exchanger 230.
The air-water interaction within cooling tower 402 causes some
water to evaporate. This evaporation extracts (heat) energy out of
the circulating water stream and transfers this energy to the
interacting air stream of cooling tower 402. The cold water
obtained by the result of the above air-water interaction is
collected in cold-water reservoir 20'. The journey of the cold
water begins again as pump 60' pumps water from cold-water
reservoir 20' through cold water outlet 65', to cold water inlet
pipe 213' into air-to-water heat exchanger 230', out warm water
outlet pipe 214', through warm water inlet 66', into water
distribution system with nozzles 51'. Since cooling tower 402
operates with an air stream comprising air with a lower wet bulb
temperature and dry bulb temperature (because of the air's trip
through air-to-water heat exchanger 230), the achievable
temperature of the cold water in cold water reservoir 20' is
substantially lower than the temperature that the cold water of
cold water reservoir 20 can achieve.
[0087] As described above for tower 402, fan 55'' of cooling tower
403 operates to pull ambient air into air inlet 35'', through
air-to-water heat exchanger 230', through the wet fill, past the
water distribution system with nozzles 51'', through the mist
eliminator 71'', up through fan 55'' and finally out air outlet
40'' of cooling tower 403. Pump 60'' pumps water from cold-water
reservoir 20'', through pipe 65'', to cooling loads 11'' and MU Air
Handling Unit 715. The warm water from the above loads is returned
back to cooling tower 403 through pipe 66''. Pipe 66'' connects to
the water distribution system with nozzles 51'' of cooling tower
403 which evenly distributes water across the top of the fill. As
the water falls by gravity through the fill of cooling tower 403,
it interacts with the moving pre-cooled air stream that has been
pre-cooled by air-to-water heat exchanger 230. The air-water
interaction within cooling tower 403 causes some water to
evaporate. This evaporation extracts (heat) energy out of the
circulating water stream and transfers this energy to the
interacting air stream of cooling tower 403. The cold water
obtained by the result of the above air-water interaction is
collected in cold-water reservoir 20''. The journey of the cold
water begins again as pump 60'' pumps water from cold-water
reservoir 20'' to cooling loads 11'' and MU Air Handling Unit.
[0088] The first cooling state, comprising cooling tower 401,
produces cold water that approaches the wet bulb temperature of the
ambient air. This cold water services air-to-water heat exchanger
230, a pre-cooling heat exchanger, located at air inlet 35' of
cooling tower 402. Cooling tower 402 composes part of cooling stage
2. Since the cooling system operates to ultimately provide
pre-cooled air to cooling tower 402, when cooling stage 2
comprising cooling tower 402 operates, it produces water that is
colder than the cold water produced by cooling stage 1. This colder
water ultimately provides cooling tower 403 with air that has an
even lower wet bulb and dry bulb temperature than previous stages
allowing cooling tower 403 to produce cold water that is even
colder than the cold water produced in the second cooling
stage.
[0089] Each of cooling towers 402 and 403 uses pre-cooled air that
has a lower wet bulb temperature than ambient air. Using the
pre-cooled air allows these cooling towers to reach significantly
lower cold water temperatures and exhaust air temperatures than
cooling towers without air pre-cooling. In some embodiments, the
cold exhaust air exiting the cooling towers is utilized as a source
of energy by the Energy Recovery Systems to further produce useable
cold water or cold air and to produce additional energy savings as
compared to traditional cooling methods. Such an embodiment is
depicted in FIG. 5.
[0090] The cooling system depicted in FIG. 5 functions
substantially similarly to that of the cooling system of FIG.
4.
[0091] In addition to the cold water generated by the cooling
towers, such as cooling towers 501, 502, 503, the cooling towers
generate exhaust air that is colder than ambient air and can be
utilized as a significant energy source for additional cooling
loads. The exhaust air exits the cooling towers through air outlets
40, 40', 40''. In some embodiments, dampers 340, 340', 340''
control exhaust air flow out of the respective cooling towers.
These dampers divert the exhaust air flow from cooling tower air
outlets 40, 40', 40''. Dampers 340, 340', 340'' can direct exhaust
air streams in the following optional ways. Option A--the dampers
direct 100% of the exhaust air through energy recovery systems 330,
330', and 330''. Option B--the dampers direct 100% of the exhaust
air through air outlet 40, 40', 40'' to the outside atmosphere
bypassing the energy recovery systems. Option C--based on cooling
load demands, the dampers split the exhaust air stream in any
desired ratio between energy recovery systems 330, 330', 330'' and
exhaust air outlets 40, 40', 40''.
[0092] As seen in FIG. 8, energy recover system 330 functions to
reclaim some of the "coldness" from the cooling tower exhaust air
by using internal fan 835 to move cool exhaust air past
air-to-water heat exchangers 830 in ERS 330. This cold source can
be used to service any appropriate cooling load that one of
ordinary skill in the art would consider suitable. Warm water from
the cooling load enters air-to-water heat exchanger 830 through
warm water inlet pipe 866 and travels through air-to-water heat
exchangers 830 where the water gives off heat to the air stream
flowing out of the cooling tower. Next cold water flows from the
cold water outlet of air-to-water heat exchangers 830 into cold
water outlet pipe 865. Cold water outlet pipe 865 carries the cold
water to the cold water inlet of cooling load 811 where the cold
water picks up heat from cooling load 811 and flows through the
warm water outlet of cooling load 811, through pump 860 into warm
water inlet pipe 866 to begin the cycle again. Pump 860 drives the
flow through the closed loop system.
Primary Cooling Load Having Pre-Cooling Coil and Final Cooling
Coil
[0093] In some embodiments the temperature of the generated cold
air, for example, in a MUAHU, is lowered in two or more steps. One
way of accomplishing two or more steps of air cooling is to use two
cooling coils in the MUAHU. Such embodiments are described below.
The first cooling step doesn't need cooling fluid as cold as the
second or final step needs. Either the cooling fluid of the first
or second cooling tower can supply the necessary cooling for the
first stage. Sometimes this disclosure refers to cooling fluid
reservoir and cooling fluid. For purposes of this disclosure, water
is sometimes used as a shorthand description of any appropriate
cooling fluid such as water, water solutions, or other neat or pure
liquids. Cooling fluid is used interchangeably with water.
[0094] Inspection of FIG. 18 reveals the cooling towers: CT-1
(1000), CT-2 (2000), and CT-3 (3000). CT-1 has an air inlet and
outlet powered by a fan. At the bottom of CT-1 sits cooling fluid
reservoir 1111. Cooling fluid reservoir 1111 is in fluid or liquid
communication with at least heat exchanger (HX) 2100. HX 2100 is
attached to or mounted in front of the air inlet to CT-2.
Essentially all of the air flowing into CT-2 passes through HX
2100. Fluid communication from reservoir 1111 is facilitated by
pump 1110. In some embodiments, reservoir 1111 is in fluid
communication with other cooling loads, indicated in FIG. 18 as "to
field cooling load from CT-1". (For purposes of this disclosure,
"liquid communication" is synonymous with "fluid communication"
unless the context of the use of"fluid communication" clearly
indicates that the term is meant to include "gaseous
communication".) Warmed cooling fluid returns from the field
cooling load as indicated by "from field cooling load to CT-1". HX
2100 connects to piping that returns warmed cooling fluid to CT-1,
as well.
[0095] CT-2 is similar. At the bottom of CT-2 sits cooling fluid
reservoir 2111. Cooling fluid reservoir 2111 is in fluid or liquid
communication with at least HX 3100. HX 3100 is attached to or
mounted in front of the air inlet to CT-3. Essentially all of the
air flowing into CT-3 passes through HX 3100. Fluid communication
from reservoir 2111 is facilitated by pump 2110. In some
embodiments, reservoir 2111 is in fluid communication with other
cooling loads, indicated in FIG. 18 as "to field cooling load from
CT-2". Warmed cooling fluid returns from the field cooling load as
indicated by "from field cooling load to CT-2". HX 3100 connects to
piping that returns warmed cooling fluid to CT-2, as well.
[0096] CT-3 is similar to CT-1 and CT-2. At the bottom of CT-3 sits
cooling fluid reservoir 3111. Cooling fluid reservoir 3111 is in
fluid or liquid communication with at least the primary cooling
load. Fluid communication from reservoir 3111 is facilitated by
pump 3110. In some embodiments, reservoir 3111 is in fluid
communication with other cooling loads, indicated in FIG. 18 as "to
field cooling load from CT-3". Warmed cooling fluid returns from
the field cooling load as indicated by "from field cooling load to
CT-3". Primary cooling load connects to piping that returns warmed
cooling fluid to CT-3, as well.
[0097] The primary cooling load depicted in FIG. 18 is an MUAHU,
but those of ordinary skill in the art will recognize that the
system described for this embodiment can provide the cooling load
for a number of cooling loads. In fact, simply replacing the
cooling coils of the MUAHU with a liquid-to-liquid heat exchanger
converts the system from cooling air to cooling a fluid.
[0098] In this embodiment one of the field cooling loads associated
with CT-1 is pre-cooing coil 3160 of MUAHU 3140. The primary
cooling load, served by CT-3, is final cooing coil 3170 of MUAHU
3140, in this embodiment.
[0099] As can be seen, the MUAHU 3140 comprises the two cooling
coils discussed above: pre-cooling coil 3160 and final cooling coil
3170. These coils are mounted inside of MUAHU 3140 downstream of
air filter 3150. This embodiment also depicts an adiabatic
humidifier 3180.
[0100] This embodiment operates similarly to those discussed above.
Operation of CT-1 begins by circulating cooling fluid using pump
1110 from cooling fluid reservoir 1111 through HX 2100, through
pre-cooling coil 3160, and perhaps additional field cooling loads.
This warmed cooling fluid returns to wet media 1112 in CT-1 and
finally back to cooling fluid reservoir 1111. At the same time, a
fan moves air into the air inlet of CT-1 up through the tower
counter to the downward flow of cooling fluid in wet media 1112.
This process evaporatively cools the warmed cooling fluid flowing
over the wet media 1112 and humidifies the exhaust air. The
now-chilled cooling fluid returns to cooling fluid reservoir
1111.
[0101] The same thing happens in CT-2 as the air moving through the
tower counter to the flow of cooling fluid through wet media 2112
couples the fluid in cooling fluid reservoir 2111. For CT-2, the
ambient air coming in has been sensibly cooled by passing through
HX 2100. The Dry Bulb and Wet Bulb of the ambient air are being
reduced without changing moisture content of the air. This lower
Wet Bulb temperature of the air allows for colder cooling fluid to
be produced by CT-2.
[0102] Likewise, CT-3 passes even cooler air at lower Wet Bulb
temperature through wet media 3111. For CT-3, the ambient air
coming in has been sensibly cooled by passing through HX 3100. The
Dry Bulb and Wet Bulb of the ambient air are being reduced without
changing moisture content of the air. This lower Wet Bulb
temperature of the air allows for colder cooling fluid to be
produced by CT-3. Thus, the temperature of the cooling fluid in
cooling fluid reservoir 3111 becomes low enough to adequately
service the final cooling load of final cooling coil 3170. Using
pre-cooling coil 3160 can greatly reduce the cooling load on the
final cooling coil 3170 being served by CT-3.
MECS Plus Supplemental Cooling Means (SCM)
[0103] In the embodiments discussed above, each of the cooling
towers is size optimized to provide the cooling capacity that the
cooling load requires. For instance, if the cooling load includes
process cooling loads and a comfort cooling load for a building,
the MECS must be configured, designed and sized to meet that load
every day of the year. Since weather or atmospheric conditions
influence the ultimate efficiency of the MECS, some days will have
a combination of temperatures, relative humidity, and other
parameters that make the day's cooling fluid generation easier than
on other days that have less favorable weather conditions. To meet
the cooling load, the MECS must be configured, designed and sized
to provide the needed amount(s) of cooling fluid at the appropriate
temperature(s) even on days with the least favorable conditions
(typically days with high enthalpy, at corresponding Dry Bulb and
Wet Bulb temperatures, which usually occurs at a high moisture
content of ambient air or high dew point).
[0104] This alternative embodiment essentially works by properly
configuring, designing and sizing the MECS to meet the cooling load
for all but some number of the most difficult days. Therefore, for
some days, it will not provide the adequate cooling fluid flow at
the appropriate temperature. To make up that shortfall in cooling
fluid flow at the appropriate temperature to meet the cooling load
application requirements, this embodiments places a means for
supplementally cooling referred to throughout as a supplemental
cooling module (SCM) in line with the MECS cooling fluid delivery
system to provide a boost in cooling fluid flow and temperature on
the difficult days. I discuss this embodiment below. In some
embodiments, the SCM attaches into the cooling lines going into or
coming out of the MECS using a fluid-to-fluid heat exchanger. An
advantage to this arrangement is that the cooling fluid of the MECS
and the cooling fluid of the SCM remain segregated
[0105] Inspection of FIG. 19 reveals three cooling towers: CT-1
1000, CT-2 2000, and CT-3 3000. CT-1 has an air inlet and outlet
powered by a fan. At the bottom of CT-1 sits cooling fluid
reservoir 1111. Cooling fluid reservoir 1111 is in fluid or liquid
communication with at least heat exchanger (HX) 2100. HX 2100 is
attached to or mounted in front of the air inlet to CT-2.
Essentially all of the air flowing into CT-2 passes through HX
2100. Fluid communication from reservoir 1111 is facilitated by
pump 1110. In some embodiments, reservoir 1111 is in fluid
communication with other cooling loads, indicated in FIG. 19 as "to
field cooling load from CT-1". Warmed cooling fluid returns from
the field cooling load as indicated by "from field cooling load to
CT-1". HX 2100 connects to piping that returns warmed cooling fluid
to CT-1, as well.
[0106] CT-2 is similar. At the bottom of CT-2 sits cooling fluid
reservoir 2111. Cooling fluid reservoir 2111 is in fluid or liquid
communication with at least HX 3100. HX 3100 is attached to or
mounted in front of the air inlet to CT-3. Essentially all of the
air flowing into CT-3 passes through HX 3100. Fluid communication
from reservoir 2111 is facilitated by pump 2110. In some
embodiments, reservoir 2111 is in fluid communication with other
cooling loads, indicated in FIG. 19 as "to field cooling load from
CT-2". Warmed cooling fluid returns from the field cooling load as
indicated by "from field cooling load to CT-2". HX 3100 connects to
piping that returns warmed cooling fluid to CT-2, as well.
[0107] CT-3 is similar to CT-1 and CT-2. At the bottom of CT-3 sits
cooling fluid reservoir 3111. Cooling fluid reservoir 3111 is in
fluid or liquid communication with at least the primary cooling
load. Fluid communication from reservoir 3111 is facilitated by
pump 3110. In some embodiments, reservoir 3111 is in fluid
communication with other cooling loads, indicated in FIG. 19 as "to
field cooling load from CT-3". Warmed cooling fluid returns from
the field cooling load as indicated by "from field cooling load to
CT-3". Primary cooling load connects to piping that returns warmed
cooling fluid to CT-3, as well.
[0108] This embodiment shows the use of three cooling towers. But
the number of cooling towers depends on the load and the expected
atmospheric design conditions. Embodiments using more than three
cooling towers can be envisioned. Moreover, the cooling towers in a
particular MECS need not have the same capacity.
[0109] SCM 4120 used any known cold or cold producing source. SCM
4120 generates chilled cooling media that is pumped through supply
piping by pump 4110 to a fluid-to-fluid heat exchanger 4130. The
cooling media returns to SCM 4120 through return piping. Cooling
media in CT-3 flows through the other side of HX 4130 where it
transfers heat to the SCM circuit dropping the temperature of the
cooling media in the CT-3 circuit.
[0110] The SCM or alternatively a means for providing supplemental
cooling may use a means for cooling selected from any number of now
known or later invented cooling systems or cold water sources
including natural sources. In some embodiments, the cooling means
is selected from different cooling fluid generating equipment or
from natural cooling fluid sources listed below: thermally driven
adsorption chillers supplying cold water or cold water-glycol
solution; thermally driven absorption chillers supplying cold water
or cold water-glycol solution; conventional mechanical water
chillers; natural cooling fluid sources; river water, sea water,
lake water, geothermal water, or other cooling sources. The
adsorption/absorption chillers could be fired as is typically done
in the art or by variations of art-known methods, such as low
pressure water steam, hot water (solar heat, waste heat,
hydrocarbon generated heat, etc.) or by direct contact with heaters
fired by natural gas, or liquid propane, etc. The condensers of the
chillers could be either water or air-cooled.
[0111] The MECS functions effectively for a majority of time during
the year in regions with low and moderate ambient humidity. The
addition of the SCM to the MECS allows it to operate year round
within all global regions even those with adverse climate.
[0112] The SCM supplies cold fluid (water) at a temperature to meet
the requirements of the cooling application. In some embodiments,
the SCM comes on line as needed with the MECS only during peak
cooling conditions (such as high ambient humidity).
MECS with Closed-Loop Cooling Towers
[0113] In addition to the open-loop cooling towers used in some of
the above embodiments, closed-loop cooling towers are useful, as
well. FIG. 20 illustrates a MECS with closed-loop cooling towers.
Of course, embodiments exist where some of the cooling towers are
closed-loop towers and some are open-loop towers.
ISECS with Control Over Individual Server Air Flow
[0114] In some embodiments, the MECS cooling system is used to
service the cooling load of one or more heat-generating electrical
or electronic devices in a process cooling manner. One set of such
embodiments uses the ISECS to cool standard electronic enclosure
server racks. These were discussed above. Other sets are discussed
below.
[0115] Approximately 20% or more of the energy used in an
individual server or individual server rack and consequently
approximately 20% of the heat generated comes from the cooling fans
in the servers.
[0116] Some embodiments of the ISECS partially or completely
transfer this air-flow function of the server fans to the ISECS
fans. In some embodiments, this allows the server fan speeds to be
slowed or deactivated. Such an embodiment is depicted in FIG. 21.
Similar to the ISECS discussed above, the embodiments have fan coil
unit (FCU) 5200 comprising housing 5201 that positions pre-cooling
coil 5210 (PCC) upstream of final cooling coil (FCC) 5220, which
is, in turn, upstream of FCU fans 5230.
[0117] While FIG. 21 shows two FCU fans 5230 and two cooling coils
5210 and 5220, various other embodiments exist that comprise one
FCU fan 5230, one cooling coil 5220, three or more FCU fans 5230,
or three or more cooling coils 5210 and 5220. Cooling coils 5210
and 5220 receive cold cooling fluid from any type of fluid cooling
system. Cooling coils 5210 and 5220 circulate cooling fluid inside
of FCU 5200.
[0118] Various embodiments exist where the fluid cooling system for
both coils is the same, the system for the coils is different, the
temperatures of the cooling fluid are the same, the temperatures of
the cooling fluids are different, the temperature of the cooling
fluid into FCC 5220 is lower than that of PCC 5210, or the
temperature of the cooling fluid into FCC 5220 is higher than that
of PCC 5210. Some embodiments use a MECS to supply the cold cooling
fluid. Some embodiments use CT-1, CT-2 or the Energy Recovery Unit
of the MECS to supply cold cooling fluid to PCC 5210 and CT-1,
CT-2, CT-3 or the Energy Recovery Unit to supply cold cooling fluid
to FCC 5220. And some embodiments use an SCM together with CT-1,
CT-2, CT-3 or Energy Recovery Unit or independently to supply cold
cooling fluid to FCC 5220.
[0119] FCU 5200 additionally comprises one or more differential
pressure transmitters (DPT) to provide pressure-drop information
throughout FCU 5200, which is used by a command-and-control unit
(in this embodiment programmable logic controller 5310 (PLC)) to
determine air-flow through FCU 5200. In some other embodiments,
other sensor means of measuring air flow velocity can be used. FCU
5200 also comprises FCU temperature sensors 5231 within housing
5201 to provide temperature data to the command-and-control unit.
In some embodiments, sensors are air temperature sensors, but
temperature sensors could be configured to provide the temperature
of any relevant or desired item inside of FCU 5200.
[0120] FIG. 21 depicts an embodiment that uses PLC 5310 as the
command-and-control unit. PLC 5310 connects to the sensors inside
of FCU 5200, specifically in this embodiment FCU 5231 air
temperature sensor and DPT 5240. DPT 5240 is shown in this
embodiment as sensing the pressure difference across FCC 5220. In
other embodiments, DPT 5240 measures other pressure drops, such as
between the entrance to FCU 5200 and the exit from FCU 5200. In yet
other embodiments, more than one DPT 5240 is used depending upon
what air-velocity and air-flow-rate measurements are needed or
desired.
[0121] In the embodiment of FIG. 21, PLC 5310 receives air-flow,
fan speed, cooling fluid flow or other data from sensors such as
DPT 5240 for air-flow through the system, fan speed (sensors not
shown), cooling fluid temperature or flow rate (sensors not shown)
or both, among other sensor input. Using the input data, PLC 5310
controls at least fan speed or cooling fluid flow rate through one
or more of cooling coil units 5210 or 5220. In some embodiments,
such as those with two or more FCU fans 5230, individual fan speeds
can be controlled to be the same or can be individually controlled.
The FIG. 21 embodiments show two FCU fans 5230 located at the exit
of FCU 5200. But FCU fans 5230 can be located at the entrance to
FCU 5200 or placed somewhere between the entrance and the exit.
Multi-fan embodiments exist in which the fans are located away from
each other.
[0122] As can be seen in the figure, FCU 5200 is located below
floor 5400 in the embodiment of FIG. 21. But embodiments exist in
which FCU 5200 is located above server rack enclosure 5100
(SRE).
[0123] PLC 5310 connects to the various sensors and controllers
through individual wires, wired local area networks or buses (such
as Ethernet, CAN, i2c, 1-wire, or any other known bus), or wireless
local area networks (using any of the widely known protocols).
[0124] In addition to FCU 5200, the ISECS embodied in FIG. 21 also
comprises components that allow PLC 5310 or an associated control
module 5300 (CM) to monitor the internal temperature of individual
servers 5110 with temperature sensor 5120 and adjust that
temperature by adjusting air flow through the individual servers
5110 individually or by individually controlling the server's
cooling-fan speed.
[0125] Additional components included baffles or gap seals 5140 to
direct air flow within enclosure 5100 and server air-flow control
dampers 5130. Air temperature within each server 5110 is measured
using server temperature sensor 5120.
[0126] In operation, servers or other electronic equipment mounted
in rack enclosures generate heat as they use electric power to
facilitate their desired functions. This raises their temperature.
Optimal operation and longevity of the server or other electronic
equipment mounted in rack enclosures calls for maintaining their
temperature below values set by their manufacturers. Each server or
other electronic equipment mounted in rack enclosures has different
loads moment to moment. This difference in loads causes a
moment-to-moment difference in temperature between the server or
other electronic equipment mounted in rack enclosures and therefore
a moment-to moment difference in cooling requirements. The
efficiency of the cooling system suffers when the cooling supplied
doesn't match with the needed cooling.
[0127] FCU fans 5230 pull air through enclosure 5100, past air
filter 5150, and into FCU 5200. Server air intakes 5135 are located
upstream of the server or other electronic equipment mounted in
rack enclosure 5100. This is typically on the front or room-facing
side of individual servers 5110. Intake 5135 is dedicated to an
individual server. Gap seals 5140 are strategically located in
enclosure 5100, for instance between servers or other electronic
equipment, so that when FCU fans 5230 pull air through enclosure
5100, a majority (>60%, >70%, >80%, >90%, or >95%)
of the incoming air must come through intakes 5135 on each
individual server 5110. This arrangement directs room air through
the front of servers 5110, across server 5110's heat-generating
components and out through vents (not shown) on the back of each
individual server 5110. This directional flow heats the air moving
through the enclosure 5100 as indicated by arrows 5160 and arrows
5161 downstream of filter 5150.
[0128] The heated air passes into FCU 5200, across PCC 5210 and FCC
5220, through FCU fans 5230, and out of FCU 5200, cooled to a
desired temperature. The cooled air eventually returns into the
room and begins another cycle through enclosure 5100 (or enclosure
of other server racks or other electronic equipment mounted in rack
enclosures in the facility).
[0129] As air moves through FCU 5200, the air pressure drops. DPT
5240 communicates the pressure drop to PLC 5310, which uses the
data to determine the air flow velocity and air-flow rate. FCU
temperature sensors 5231 communicate air temperature data to PLC
5310.
[0130] From various data, such as cooling fluid temperature in one
or more cooling coils 5210 and 5220, air flow rate, cooling fluid
flow rate, server power usage, etc. PLC 5310 controls the speed of
FCU fan 5230 (associated with air velocity and air-flow rate
through FCU 5200) and cooling fluid flow rate through one or more
cooling coils 5210 and 5220 to maintain the room air temperature
with a range around a temperature set point. PLC 5310 controls
coiling-coil flow rates by controlling valves 5250 and 5260. PLC
5310 connects to valves 5250 and 5260 through individual wires or
through the wired or wireless LANs or buses discussed above.
[0131] As this process continues CM 5300 either alone or under PLC
5310's control monitors server 5110 power usage and the internal
temperature of servers 5110. Server temperature sensors 5120 supply
the internal temperature data to CM 5300. CM 5300 controls the
temperatures by further opening or closing server air-flow dampers
5130 (each one associated with an individual server 5110). Further
opening or closing a damper 5130 causes the associated server to
receive more or less cooling air. CM 5300 controls the temperature
of each server 5110 within a range of a set-point temperature,
which may be the same as or different from the set-point of FCU
5200. The server 5110 temperatures could be controlled in a group
if desired instead of individually.
MECS Plus ISECS Plus SCM Inline with HX
[0132] In FIG. 22, an embodiment of the ISECS has a MECS cooling
system paired with an SCM, as described above. In this embodiment,
the MECS services one or more ISECS.
[0133] Pump 1110 circulates cooling fluid from cooling fluid
reservoir 1111, associated with CT-1, to HX 3620 in addition to
circulating it to HX 2100 associated with CT-2. After the cooling
fluid passes through HX 3620, it returns warmed cooling fluid to
wet media 1112. This embodiment shows only two cooling loads on
CT-1, but embodiments exist in which CT-1 services additional
cooling loads.
[0134] Returning to FIG. 22, pump 3621 pumps cooling fluid in a
closed loop through HX 3620, a liquid-liquid heat exchanger, to PCC
3700 and back. Similarly, pump 3110 pumps cooling fluid from
cooling fluid reservoir 3111 to HX 3630 and returns warmed cooling
fluid to wet media 3112. This embodiment shows only a single
cooling load on CT-3, but embodiments exist in which CT-3 services
additional cooling loads.
[0135] Returning to FIG. 22, pump 3631 pumps cooling fluid in a
closed loop through HX 3630, a liquid-liquid heat exchanger, to FCC
3800 and back. In some embodiments, pump 3631 pumps cold cooling
fluid to and from other FCUs. The embodiment depicted in FIG. 22
further comprises HX 3710, a liquid-liquid HX, which has one side
connected into the cooling circuit serviced by pump 3631. SCM 3640
is connected to the other side of HX 3710. The circuit connecting
SCM 3640 to HX 3710 is serviced by pump 3641. SCM 3640 is similar
to the SCMs discussed above. This arrangement allows SCM 3640 to
service or boost the cooling of several FCUs simultaneously.
[0136] The MECS portion of this embodiment operates as discussed
above, wherein sometime after starting, the MECS reaches a state
where each of the cooling reservoirs, 1111, 2111, and 3111 are cold
(although each has a different temperature). This state services
the cooling load presented by the ISECS. Servicing the cooling load
includes supplying cold cooling fluid to PCC 3700 and FCC 3800
located in enclosure 3141 of FCU 3140. Pump 1110 circulates cold
cooling fluid through the CT-1 circuit. One side of HX 3620 is part
of the CT-1 circuit. Pump 3621 circulates cooling fluid through the
PCC circuit. The other side of HX 3620 is part of the PCC circuit.
As cooling fluid circulates through the PCC circuit, the cooling
fluid is chilled as it passes through HX 3620. The PCC circuit
circulates this chilled fluid to PCC 3700. CT-1 through HX 3620
cools one side of HX 3620 allowing the other side of HX 3620 to
cool the fluid in the PCC loop. Likewise, pump 3110 circulates cold
cooling fluid through the CT-3 circuit. One side of HX 3630 is part
of the CT-3 circuit. Pump 3631 circulates cooling fluid through the
FCC circuit. The other side of HX 3630 is part of the FCC circuit.
As cooling fluid circulates through the FCC circuit, the cooling
fluid is chilled as it passes through HX 3630. The FCC circuit
circulates this chilled fluid to FCC 3800. CT-3 through HX 3630
cools one side of HX 3630 allowing the other side of HX 3630 to
cool the fluid in the FCC loop.
[0137] At a second state, the PCC 3700 and FCC 3800 combine to cool
hot air that comes from the SRE (not shown). The hot air enters and
passes by PCC 3700 and FCC 3800 pulled by FCU fan 3190. During this
movement, the air is chilled. Finally, the cold air returns to the
IT room.
[0138] When the atmospheric conditions are favorable, operating the
MECS provides enough cooling capacity to maintain the temperature
of the air returning to the IT room at or below a set-point
temperature. In other words, the servers in the server rack
enclosure are adequately cooled. The circuit containing SCM 3640 is
present, but powered down. When the atmospheric conditions are
unfavorable, operating the MECS may not adequately service the
load. At that point, perhaps detected by the temperature of the
cooling fluid in the CT-3 cooling circuit, the command-and-control
device (not shown) starts SCM 3640, which provides additional
cooling to the HX 3800 cooling circuit, which allows the MECS to
meet the cooling load.
ISECS plus MECS plus SCM Inline with FCC
[0139] In FIG. 23, an embodiment of the ISECS has a MECS cooling
system paired with an SCM, as described above. In this embodiment,
the MECS services one or more ISECS.
[0140] Pump 1110 circulates cooling fluid from cooling fluid
reservoir 1111, associated with CT-1, to HX 4135, a liquid-liquid
heat exchanger, in addition to circulating it to HX 2100 associated
with CT-2. After the cooling fluid passes through HX 4135, it
returns warmed cooling fluid to wet media 1112. This embodiment
shows only two cooling loads on CT-1, but embodiments exist in
which CT-1 services additional cooling loads.
[0141] Returning to FIG. 23, pump 4160 pumps cooling fluid in a
closed loop through the other side of HX 4135 to PCC 3160 and back.
Similarly, pump 3110 pumps cooling fluid from cooling fluid
reservoir 3111 to HX 4130, a liquid-liquid heat exchanger, and
returns warmed cooling fluid to wet media 3112. This embodiment
shows only a single cooling load on CT-3, but embodiments exist in
which CT-3 services additional cooling loads.
[0142] Returning to FIG. 23, pump 4136 pumps cooling fluid in a
closed loop through the other side of HX 4130 to FCC 3170 and back.
In some embodiments, pump 4136 pumps cold cooling fluid to and from
other FCUs. The embodiment depicted in FIG. 23 further comprises HX
4170, a liquid-liquid HX, which has one side connected into the
cooling circuit serviced by pump 4136. SCM 4120 is connected to the
other side of HX 4170. The circuit connecting SCM 4120 to HX 4170
is serviced by pump 4110. SCM 4120 is similar to the SCMs discussed
above. This arrangement restricts SCM 4120 to servicing or boosting
the cooling of a single FCC (in this embodiment FCC 3170).
[0143] The MECS portion of this embodiment operates as discussed
above; sometime after starting, the MECS reaches a state where each
of the cooling reservoirs, 1111, 2111, and 3111 are cold (although
each has a different temperature). This state services the cooling
load presented by the ISECS. Servicing the cooling load includes
supplying cold cooling fluid to PCC 3160 and FCC 3170 located in
enclosure 3141 of FCU 3140. Pump 1110 circulates cold cooling fluid
through the CT-1 circuit. One side of HX 4135 is part of the CT-3
circuit. Pump 4160 circulates cooling fluid through the PCC
circuit. The other side of HX 4135 is part of the PCC circuit. As
cooling fluid circulates through the PCC circuit, the cooling fluid
is chilled as it passes through HX 4135. The PCC circuit circulates
this chilled fluid to PCC 3160. CT-1 through HX 4135 cools one side
of HX 4135 allowing the other side of HX 4135 to cool the fluid in
the PCC loop. Likewise, pump 3110 circulates cold cooling fluid
through the CT-3 circuit. One side of HX 4130 is part of the CT-3
circuit. Pump 4136 circulates cooling fluid through the FCC
circuit. The other side of HX 4130 is part of the FCC circuit. As
cooling fluid circulates through the FCC circuit, the cooling fluid
is chilled as it passes through HX 4130. The FCC circuit circulates
this chilled fluid to FCC 3170. CT-3 through HX 4130 cools one side
of HX 4130 allowing the other side of HX 4130 to cool the fluid in
the FCC loop.
[0144] At a second state, PCC 3160 and FCC 3170 combine to cool the
hot air coming from the SRE (not shown). This hot air enters and
passes by PCC 3160 and FCC 3170 pulled through FCU 3140 by FCU fan
3190. As the hot air passes over PCC 3160 and FCC 3170, the air is
cooled. Finally, the cold air returns to the IT room.
[0145] When the atmospheric conditions are favorable, operating the
MECS provides enough cooling capacity to maintain the temperature
of the air returning to the IT room at or below a set-point
temperature. In other words, the servers in the server rack
enclosure are adequately cooled. The circuit containing SCM 4120 is
present, but powered down. When the atmospheric conditions are
unfavorable, operating the MECS may not adequately service the
load. At that point, perhaps detected by the temperature of the
cooling fluid in the cooling circuit of FCC 3170, the
command-and-control device (not shown) starts SCM 4120, which
provides additional cooling to FCC 3170.
[0146] In FIG. 24, an embodiment of the ISECS has a MECS cooling
system paired with an SCM, as described above. In this embodiment,
the MECS services one or more ISECS.
[0147] Pump 1110 circulates cooling fluid from cooling fluid
reservoir 1111, associated with CT-1, to HX 4150, a liquid-liquid
heat exchanger, in addition to circulating it to HX 2100 associated
with CT-2. After the cooling fluid passes through HX 4150, the
warmed cooling fluid returns to wet media 1112. This embodiment
shows only two cooling loads on CT-1, but embodiments exist in
which CT-1 services additional cooling loads.
[0148] Returning to FIG. 24, pump 4151 pumps cooling fluid in a
closed loop through the other side of HX 4150 to PCC 3160 and back.
Similarly, pump 3110 pumps cooling fluid from cooling fluid
reservoir 3111 to HX 4130, a liquid-liquid heat exchanger, and
returns warmed cooling fluid to wet media 3112. This embodiment
shows only a single cooling load on CT-3, but embodiments exist in
which CT-3 services additional cooling loads.
[0149] Returning to FIG. 24, pump 4131 pumps cooling fluid in a
closed loop through the other side of HX 4130 to FCC 3170 and back.
In some embodiments, pump 4131 pumps cold cooling fluid to and from
other FCUs.
[0150] In this embodiment, FCU 3140 comprises an additional cooling
coil serviced by SCM 4120. This coiling coil is sometimes called
SCC 4180. The circuit connecting SCM 4140 to SCC 4180 is serviced
by pump 4110. SCM 4140 is similar to the SCMs discussed above. SCM
4120 provides a boost to the cooling directly to the air stream
through SCC 4180. In some embodiments, SCM 4140 services SCCs
located in more than one FCU.
[0151] The MECS portion of this embodiment operates as discussed
above; sometime after starting, the MECS reaches a state where each
of the cooling reservoirs, 1111, 2111, and 3111 are cold (although
each has a different temperature). This state services the cooling
load presented by the ISECS. Servicing the cooling load includes
supplying cold cooling fluid to PCC 3160 and FCC 3170 located in
enclosure 3141 of FCU 3140. Cold cooling fluid gets to PCC 3160
through the action of pump 4151. As cooling fluid circulates
through the CT-1 circuit, it cools the cooling fluid of the PCC
circuit as the respective cooling fluids pass through opposing
sides of HX 4150. The action of pump 1110 cools one side of HX 4150
allowing the other side of HX 4150 to cool the fluid in the PCC
loop.
[0152] At a second state, PCC 3160 and FCC 3170 combine to cool the
hot air coming from the SRE (not shown). This hot air enters and
passes by PCC 3160 and FCC 3170 pulled through FCU 3140 by FCU fan
3190. As the hot air passes over PCC 3160, FCC 3170, and SCC 4180,
the air is cooled. Finally, the cold air returns to the IT
room.
[0153] When the atmospheric conditions are favorable, operating the
MECS provides enough cooling capacity to maintain the temperature
of the air returning to the IT room at or below a set-point
temperature. In other words, the servers in the server rack
enclosure are adequately cooled. The circuit containing SCM 4120 is
present, but powered down. SCM 4120 doesn't provide any cooling in
this state. When the atmospheric conditions are unfavorable,
operating the MECS may not adequately service the load. At that
point, perhaps detected by the temperature of the air in FCU 3140,
the command-and-control device (not shown) starts SCM 4120, which
provides additional cooling by circulating cold cooling fluid to
SCC 4180.
[0154] To present a better understanding of the design and
operational specifics of the MECS, demonstration of its cooling
capability and performance, and for eventual comparison with a
Conventional Mechanical Refrigeration System, the following design
conditions are used to provide a comparable engineering analysis
for both systems performing equal tasks:
EXAMPLES
Example 1
Cooling Application
[0155] a) Cool a conditioned space with the summer design sensible
cooling load of approximately 92 tons of equivalent refrigeration.
[0156] b) Project Location--Phoenix, Ariz. [0157] c) The ASHRAE
specified design ambient air parameters for Phoenix Ariz. for
cooling applications are 110.2.degree. F. DB and 70.degree. F. WB.
[0158] d) The ASHRAE specified design ambient air parameters for
Phoenix Ariz. for evaporation applications for 0.4% are
76.1.degree. F. WB and 96.4.degree. F. MCDB (Mean Coincident dry
bulb temperature). (For reference only) [0159] e) The indoor design
air temperature is approximately 80.degree. F. DB at a comfortable
40 to 65% relative humidity range. [0160] f) The preliminary
estimate of required volume of makeup/supply cooled air into the
conditioned space is approximately 35,000 CFM.
[0161] These calculations are provided as illustrative example only
for the exemplary system described herein. They do not limit the
invention in any way and are only provided to guide the user in
implementing other equivalent implementations of the invention.
[0162] Typical MECS engineering design and component list selected
for performing the above-mentioned cooling.
[0163] The MECS is configured for this particular application, and
it consists of the following main components: [0164] Three induced
draft counter flow cooling towers or comparable Air Washers;
variable speed exhaust air fans; and variable flow circulating
water pumps; and, [0165] Pre-cooling coils located at the ambient
air inlets of the cooling towers.
[0166] The components of makeup air-handling unit 715 sit in the
following sequence and following the airflow direction. Powered by
a fixed or variable speed supply fan 735, ambient air passes
through the air inlet 720 of makeup air-handling unit 715. Then it
passes through air particulate filter(s) 750 and air-to-air heater
exchanger 745. Air flow through air-to-air heat exchanger 745 is
assisted by fan 755. This air flow is building exhaust air, which
pre-cools ambient air destined for introduction into the building.
Next, it reaches cooling coil 740. Cold water is pumped from a
cooling stage of a cooling system, through pipe 65' through the
cold water inlet 213 to cooling coil 740 of makeup air-handling
unit 715 and then through the cooling coil 740 to the warm water
outlet 214 to pipe 66' back to the cooling system. As air passes
over cooling coil 740, it gives off heat to the cold water causing
the temperature of the air to fall providing sensible cooling.
[0167] In applications where the space does not required 100%
ambient air but still has the same space cooling load, the
air-to-air heat exchanger 745 could be replaced with an air-mixing
module (not shown). The air-mixing module mixes large volumes of
lower temperature return air from the conditioned space with the
minimal required volume of ambient air (ventilation air). This
mixed air application will significantly reduce the total energy
consumption of the MECS. (Note: If this air-mixing application is
implemented, the need for humidification is greatly reduced or
eliminated in most cases.)
[0168] Return Air Sub-System (RA Sub-System)--the RA Sub-System
contains ductwork, an adiabatic humidification chamber, and return
air exhaust fan. The RA Sub-System controls temperature, humidity,
and air volume of the return air stream being fed to one side of
the air-to-air heat exchanger 745 or to the air-mixing module.
[0169] The integrated MECS contains the following sequential
process cooling stages:
Cooling Stage-1 (Water Cooling)
[0170] From FIG. 6, this cooling stage comprises cooling tower 601
and a water pump 60. Cooling tower 601 generates cold water that
collects in its cold-water reservoir 20. Cooling stage-1 generates
cold water for pre-cooling ambient air entering into the next stage
cooling towers. The cooling coil (air-to-water heat exchanger 230)
pre-cools ambient air entering into the next stage cooling tower
601' using some of the cold water from cooling tower 601.
Cooling Stage-2 (Water Cooling)
[0171] This cooling stage comprises a second cooling tower 601', a
water pump 60', and a cooling coil (air-to-water heat exchanger
230'). Cooling tower 601' generates cold water that collects in its
cold-water reservoir 20' and supplies cold water to the
air-to-water heat exchanger 230' of the third cooling tower
601''.
Cooling Stage-3 (Water Cooling)
[0172] This cooling stage comprises third cooling tower 601'', a
water pump 60'', and a cooling coil (air-to-water heat exchanger
230'). Cooling tower 601'' generates cold water that collects in
its cold-water reservoir 20'', and supplies cold water to a cooling
coil (air-to-water heat exchanger 740) installed in the housing of
makeup air-handling unit 715 or some other cooling load or process
cooling load.
Cooling Stage-4 (Makeup Air Cooling)
[0173] This cooling stage comprises a cooling coil (air-to-water
heat exchanger 740) installed in the makeup air-handling unit. The
cooling coil (air-to-water heat exchanger 740) receives cold water
from third cooling tower 601''. The cooling coil (air-to-water heat
exchanger 740) sits in the housing of makeup air-handling unit 715
downstream of an air-to-air heat exchanger 745 and can either cool
air leaving the air-to-air heat exchanger 745 or, if the air-to-air
heat exchanger is not included, pre-cools warm ambient air as it
enters into the makeup air-handling unit 715.
Cooling Stage-5 (Makeup Air Cooling)
[0174] This stage is the final cooling stage inside of the makeup
air-handling unit 715. It provides adiabatic cooling of the supply
air using any suitable direct evaporative cooling system 732, such
as using high pressure water fogging nozzles.
Cooling Stage-6 (Return Air Cooling)
[0175] This cooling stage is a part of the return air RA
Sub-System, combining the return air (RA) ductwork, evaporative air
humidification chamber, and the RA exhaust fan. The humidification
chamber comprises a humidifier that could be either a high-pressure
water dispersion type, or any other evaporative humidifier type
appropriate for the application. The purpose of cooling stage-6 is
to provide high-efficiency adiabatic cooling of the RA stream
before its heat exchange interaction with the warm ambient air
stream in the air-to-air heat exchanger 745, or before mixing with
ambient air (ventilation air) in the air-mixing module, if the
cooling system is configured to use an air-mixing module.
Cooling Stage-7 (Makeup Air Cooling)
[0176] This cooling stage is an air-to-air heat exchanger and its
function is to pre-cool outside warm air using the lower
temperature return air stream from the conditioned space and
thereby reduce the MECS total energy use.
[0177] Different cooling applications call for varying MECS
configurations.
[0178] Each MECS is configured to produce the required amount of
cooling for a defined application, such as conditioned space or
process cooling for industry. Each design factors in the peak
cooling demand at summer conditions for the local environment.
[0179] The MECS has a dedicated control and monitoring system with
appropriate software to provide optimum, moment-to-moment control
over operating parameters that yield the required amount of cooling
at minimal power consumption based on constantly changing building
cooling loads, process cooling loads, and ambient air
conditions.
MECS Cooling Stages--Divided into Water and Air Cooling Stages
[0180] Described in a different way, in general, all cooling stages
of MECS fall into two states: a water-cooling stage and an
air-cooling stage.
A. Water Cooling Stages
[0181] The three water-cooling stages of the MECS use three cooling
towers 601,601',601'' with each stage having a cooling tower, a
cooling coil (optional in the first cooling tower), and a pump
arranged in series to provide a cascade of cooling stages. That is,
the cooling tower of a preceding stage generates cold water
similarly to prior art cooling towers. This cold water is used to
pre-cool the incoming air of a succeeding stage, allowing the
cooling tower of the succeeding stage to produce cooler water than
was possible in the preceding stage. In some embodiments, this
cascading of one cooling tower after another with a lower stage
bolstering the cooling ability of a higher stage continues, giving
cooling systems with 3, 4, 5, or more successive stages, each stage
capable of producing cold water at successively colder
temperatures.
[0182] MECS operation begins with a command from the central
computer of the energy management system and from the local
programmable logic controller. The operation of the MECS takes
place in the following sequential steps:
Step-1
[0183] The fan 655 of the first cooling tower 601 starts, using a
slow start method. Water circulating pump 60 starts, using a slow
start method. The pump 60 takes cold water from the cold-water
reservoir 20 and directs the water to pre-cooling coil
(air-to-water heat exchanger 230) installed at the ambient air
intakes of another cooling tower(s), respectively. Water, warmed by
pre-cooling coils, returns to the source cooling tower and
distributes the water evenly over the top of cooling tower fill,
positioning it for continuing the evaporative cooling cycle.
Step-2
[0184] The fan 655' in the second cooling tower 601' starts, using
a slow start method. The water circulating pump 60' starts, using a
slow start method. The pump 60' takes cold water from cold-water
reservoir 20' and directs the water to pre-cooling coil
(air-to-water heat exchanger 230') installed at the ambient air
intakes of the next stage cooling tower 601''. Warmed water from
the pre-cooling coil returns to the source cooling tower 601' and
distributes the water evenly over the top of the fill of the
cooling tower for continuing the evaporative cooling cycle.
Step-3
[0185] The fan 655 "of the third cooling tower 601" starts, using a
slow start method. The water circulating pump 60'' starts, using a
slow start method. The pump 60'' takes cold water from the
cold-water reservoir 20'' and directs the water to pre-cooling coil
(air-to-water heat exchanger 740') installed in the makeup
air-handling unit 715. The warm water from the pre-cooling coil
returns to the source cooling tower 601' and distributes the water
evenly over the top of the fill for continuing the evaporative
cooling cycle.
[0186] Due to the heat-mass transfer process taking place in the
fill of all cooling towers, part of the water falling over the
cooling tower fill evaporates and this evaporation process lowers
the temperature of the remaining water that is falling through the
cooling tower and collected in the cold-water reservoirs. The dry
bulb temperature of ambient air entering into the pre-cooling coils
is higher than the temperature of the cooling coil cooling water.
The pre-cooling coils extract some amount of heat from the ambient
air and, as a result, the dry bulb and wet bulb temperatures of the
ambient air falls (is lowered). The calculations for the embodiment
assume approach temperatures for cooling towers 2.degree. F., and
approach temperatures for pre-cooling coils 3.degree. F.
[0187] These approach temperatures have been selected as
illustrative examples only for the exemplary system described
herein. Other approach temperatures may be applied that will
provide a varying degree of results. The cooling towers may have
approach temperatures that are different from one another or that
are the same. Pre-cooling coils may have approach temperatures that
are different from one another or that are the same.
Step-4
[0188] Supply fan 735 of makeup air-handling unit 715 starts, using
a slow start method.
Step-5
[0189] The RA exhaust fan of the RA Sub System starts, using the
slow start method.
Step-6
[0190] After the cooling system achieves the desired cold air
supply from the makeup air-handling unit and achieves the desired
temperature for the air leaving the pre-cooling coil, the control
system, based on established parameters, activates the humidifier
730 at its minimum capacity and gradually adjusts its
humidification capacity to humidify air as set out in the specific
design specifications of the application for the conditioned
space.
Step-7
[0191] After the cooling system achieves the desired cold air
supply from the makeup air-handling unit 715, the control system
adjusts and regulates the return air fan to meet the desired volume
of return air.
Step-8
[0192] After the supply and return airflows are balanced as
desired, the control system activates the humidifier in the RA Sub
System at its minimum capacity and gradually adjusts its
humidification capacity until it optimizes the humidification level
to provide the lowest possible temperature of the return air
stream. Lower air stream temperatures at this point provide maximum
pre-cooling of ambient air in the air-to-air heat exchanger.
Example 2
[0193] The following estimates show cold water temperatures leaving
the cooling towers for a cooling system design based on summer
ambient air conditions for Phoenix, Ariz., and according to the
MECS (cooling system) design. Since ASHRAE-specified design ambient
air parameters for Phoenix, Ariz., for evaporation applications for
0.4% are 76.1.degree. F. WB and 96.4.degree. F. MCDB (evaporative
application) exist at peak conditions for only a very short cooling
time, these analysis and calculations focus on the ASHRAE Cooling
Application corresponding to ambient air parameters for Phoenix,
Ariz., of 110.2.degree. F. DB and 70.0.degree. F. WB temperatures.
These parameters approximate some of the least favorable conditions
for using evaporative cooling systems in Phoenix.
[0194] The estimated theoretical temperatures of cold water exiting
any cooling tower with a design approach temperature of 2.degree.
F. operating at the design ambient air conditions of 76.1.degree.
F. WB and 96.4.degree. F. MCDB (evaporative application) without
using pre-cooling coils is approximately 78.1.degree. F.
[0195] The estimated theoretical temperatures of cold water exiting
a similarly designed cooling tower operating while not using a
pre-cooling coil and cooling towers operating while using
pre-cooling coils at the design ambient air conditions of
76.1.degree. F. WB and 96.4.degree. F. MCDB (evaporative
application) are approximately 78.1.degree. F., 73.6.degree. F. and
72.6.degree. F., respectively.
[0196] The estimated theoretical temperatures of cold water exiting
any cooling tower with a design approach temperature of 2.degree.
F. (operating without pre-cooling coils) at the design ambient air
conditions of 110.degree. F. DB and 70.degree. F. WB (cooling
application) is approximately 72.degree. F.
[0197] The estimated theoretical temperatures of cold water exiting
a similarly designed cooling tower operating while not using a
pre-cooling coil and second and third stage cooling towers
operating while using pre-cooling coils at the design ambient air
conditions of 110.degree. F. DB and 70.degree. F. WB (cooling
application) are approximately 72.degree. F., 60.2.degree. F. and
55.5.degree. F., respectively.
[0198] The design approach temperature for all the cooling towers
is 2.degree. F. The design approach temperature for all cooling
coils in this calculation is 3.degree. F. But approach temperatures
may change to meet specific cooling design applications for
specific locations and design parameters and will result in varying
cooling results.
[0199] It should be noted that the estimated temperature values of
cold water shown above for the cooling and evaporative applications
does not include the pre-cooling of ambient air in the cooling coil
located at the air intake of the first cooling tower. If the MECS
design includes the cooling effect of the cooling coil, the water
temperatures leaving the next stage cooling towers would be
lower.
Sequential Cold Water Temperature Chain of the MECS Water Cooling
Stages
[0200] The temperature of cold water exiting the third cooling
tower is approximately 55.5.degree. F., lower than the temperature
of cold water exiting the second cooling tower, and the temperature
of cold water exiting the second cooling tower is approximately
60.2.degree. F., lower than the temperature of cold water exiting
the first cooling tower, which is approximately 72.degree. F.
Another means of stating the above is that the temperature of cold
water exiting cooling towers is that the third cooling tower is
approximately 55.5.degree. F. which is less than the second cooling
tower of approximately 60.2.degree. F. which is less than the first
cooling tower of approximately 72.degree. F. In this design
example, the initial ambient air wet bulb temperature is 70.degree.
F. Therefore, in this example, an invention cooling system provides
evaporatively cooled cold water exiting the final cooling tower at
approximately 55.5.degree. F., which is lower than the 70.degree.
F. initial wet bulb temperature of the ambient air.
[0201] Some invention cooling systems achieve these effects using
various methods and systems consisting of the following:
[0202] Pre-cooling the ambient air entering into the cooling
tower(s) with cooling coil(s) to provide sensible cooling of the
entering air for lowering the ambient air's dry bulb and wet bulb
temperatures.
[0203] If more than one cooling tower is arranged in series
(cascaded) to meet a specific application, cold water from a first
stage cooling tower is supplied to the cooling coil of the second
cooling tower and to other optional cooling loads. Cold water from
a second stage cooling tower is supplied to the coiling coil to a
third or subsequent stage cooling towers and to other optional
cooling loads. Cold water from a second, third, or greater stage is
supplied to the cooling coil in the makeup air-handling unit and
may be supplied to other optional cooling loads.
[0204] For the specific local design conditions and specific
cooling application, the piping system configuration supplying cold
water or cold air to the air or water cooling loads can be modified
to provide flexibility in operating any combination of cooling
towers.
[0205] In all cases, invention methods of arranging the cooling
towers in a series/cascade providing for the operation of the
cooling tower combinations using special direct/indirect
evaporation techniques is able to generate cold water with a final
temperature lower than the initial wet bulb temperature of ambient
air. The temperature of cold water generated by MECS can be used to
satisfy a majority of HVAC and process cooling applications while
using significantly lower energy as compared to conventional
mechanical refrigeration systems.
Air Cooling Stages
[0206] The makeup air-handling unit cools the makeup air for this
particular application. The makeup air-handling unit comprises a
pre-cooling coil providing sensible cooling (cooling stage-4) of
the ambient air, an evaporative humidifier providing additional (if
necessary) adiabatic cooling of the makeup air (cooling stage-5),
and either an air-to-air heat exchanger (cooling stage-7) or
air-mixing section or both use the return air from the conditioned
space.
Cooling Stage-4 (Makeup Air Cooling)
[0207] The makeup air-handling unit fan pulls the required amount
of the makeup (ambient) air into the makeup air-handling unit
housing through the air intake louver. The air then passes through
the air filter section, the air-to-air heat exchanger section, and
enters into the pre-cooling coil, which cools makeup air using cold
water supplied from cooling tower. (Note: At this point, it is not
assumed that an air-to-air heat exchanger is incorporated thereby
facilitating the next statement.) Air enters pre-cooling coil at
conditions of 110.2.degree. F. DB and 70.degree. F. WB temperature
and leaves pre-cooling coil at approximately 58.5.degree. F. DB and
51.5.degree. F. WB temperature. The sensible cooling load for
pre-cooling coil for a cooling application described herein is
approximately 168.0 tons of equivalent refrigeration.
[0208] Note: For demonstration of the available cooling capacity of
the MECS, we do not take into consideration the heat rejected from
the ambient air stream by pre-cooling the return air stream in the
air-to-air heat exchanger.
Cooling Stage-5 (Makeup Air Cooling)
[0209] Cooling Stage-5 further increases cooling capacity of the
cooled supply air, reducing its dry bulb temperature by means of
adiabatic cooling of ambient air coming through the pre-cooling
coil. Cooling Stage-5 comprises an evaporative air humidifier
installed in the makeup air-handling unit housing downstream of the
supply air fan. The adiabatic cooling capacity of cooling stage-5
is approximately 96,485 BTU/hr or 8 tons of equivalent
refrigeration. The humidifier could be either a high-pressure water
dispersion type or any other type of evaporative humidifier
appropriate for the application. The integrated part of the cooling
stage-5 is a mist eliminator situated downstream of the humidifier.
The parameters of the supply air leaving cooling stage 5 and
entering into the conditioned space are approximately 51.8.degree.
F. DB and 51.3.degree. F. WB at the total supply airflow rate of
approximately 35,000 CFM (air mass flow is equivalent to 160,809
lbs/hr). Assuming a condition space temperature of 80.degree. F.
DB, the assimilating sensible cooling capacity of the supply air is
approximately 92 tons of equivalent refrigeration.
Cooling Stage-6 (Return Air Cooling)
[0210] The air cooling stage-6 provides the high-efficiency
adiabatic cooling of the RA stream to reduce its temperature as low
as possible before its heat exchange interaction with the warm
ambient air stream in the air-to-air heat exchanger which is part
of cooling stage-7. This air cooling stage-6 is a part of the RA
Sub-System, combining the RA ductwork, evaporative air
humidification chamber, and the air-to-air heat exchanger
physically located in the makeup air-handling unit housing. The
humidification chamber comprises the humidifier, which could be
either a high-pressure water dispersion type or any other
appropriate type of evaporative humidifier matching the
application. The integrated part of cooling stage-6 is a mist
eliminator situated downstream of the humidifier in the
humidification chamber.
Cooling Stage-7 (Makeup Air Cooling)
[0211] Cooling Stage-7 allows significant reduction in the total
energy usage by the MECS, especially at peak conditions, by
pre-cooling ambient air using the lower temperature return air from
the conditioned space. In our case, the estimated temperature of
the adiabatically cooled RA entering the air-to-air heat exchanger
could be within approximately 75-76.degree. F. DB range while the
temperature of ambient air entering the air-to-air heat exchanger
is 110.2.degree. F. DB. The anticipated heat transfer efficiency of
the heat exchanger with the above interacting airstreams is
approximately 70%.
[0212] Cooling Stage-7 consists of an air-to-air heat exchanger
situated at ambient air intake of the makeup air-handling unit, RA
exhaust fan, and RA ductwork. The RA exhaust fan is installed at
the strategic location-downstream of the air-to-air heat exchanger.
This location of the RA exhaust fan makes the following positive
energy impacts:
[0213] It increases the total amount of heat extracted from the
warm ambient air stream by eliminating the fan heat going to the RA
stream resulting in the production of cooler makeup air entering
into pre-cooling coil and reducing the cooling load on the
pre-cooling coil.
[0214] It decreases the required amount of cold water used by
pre-cooling coil, and reduces the energy consumption of all the
operating cooling towers and their respective water circulating
pump(s).
[0215] The makeup air-handling unit of the MECS supplies into the
conditioned space approximately 35,000 CFM of cooled air at the
estimated parameters of 51.8.degree. F. DB and 51.3.degree. F. WB.
The initial design parameters of ambient air entering into the
makeup air-handling unit are 110.2.degree. F. DB and 70.degree. F.
WB temperatures. The indoor air design parameters for the
conditioned space are approximately 80.degree. F. DB and
62.3.degree. F. WB temperatures. The cooling capacities of the air
cooling stages of the makeup air-handling unit are: [0216] Air
Cooling Stage-4 168 tons of equivalent refrigeration. [0217] Air
Cooling Stage-5 (sensible equivalent adiabatic cooling) 8 tons of
equivalent refrigeration.
[0218] The total gross air cooling capacity of the makeup
air-handling unit in this example is approximately 176 tons of
equivalent refrigeration. The total sensible cooling load for
cooling 160,809 lbs/hr of ambient air mass at initial temperatures
of 110.2.degree. F. DB and 70.degree. F. WB to supply air
temperatures of 51.8.degree. F. DB and 51.3.degree. F. WB is
approximately 170 tons of equivalent refrigeration. Therefore, to
cool specified amounts of ambient air from the initial design
parameters to the specified parameters of the supply requires a net
of approximately 170 tons of equivalent refrigeration.
[0219] 35,000 CFM (mass flow rate 160,809 lbs/hr) of supply air at
approximate conditions of 51.8.degree. F. DB and 51.3.degree. F. WB
temperatures can provide specified indoor air conditions of
80.degree. F. DB and relative humidity of 62.3% in the conditioned
space. The corresponding net sensible cooling capacity of the cold
supply air is approximately 92 tons of equivalent
refrigeration.
[0220] Note: The design parameters of the return air exiting the
conditioned space and entering into RA Sub-System are approximately
80.degree. F. DB and 62.3.degree. F. WB temperatures.
[0221] While particular embodiments of the present invention have
been shown and described, it will be obvious to those skilled in
the art that changes and modifications can be made without
departing from the embodiments of this invention in its broader
aspects and, therefore, the appended claims are to encompass within
their scope all such changes and modifications as fall within the
true, intended, explained, disclose, and understood scope and
spirit of this invention's multitudinous embodiments and
alternative descriptions.
[0222] Additionally, various embodiments have been described above.
For convenience's sake, combinations of aspects composing invention
embodiments have been listed in such a way that one of ordinary
skill in the art may read them exclusive of each other when they
are not necessarily intended to be exclusive. But a recitation of
an aspect for one embodiment is meant to disclose its use in all
embodiments in which that aspect can be incorporated without undue
experimentation. In like manner, a recitation of an aspect as
composing part of an embodiment is a tacit recognition that a
supplementary embodiment exists that specifically excludes that
aspect. All patents, test procedures, and other documents cited in
this specification are fully incorporated by reference to the
extent that this material is consistent with this specification and
for all jurisdictions in which such incorporation is permitted.
[0223] Moreover, some embodiments recite ranges. When this is done,
it is meant to disclose the ranges as a range, and to disclose each
and every point within the range, including end points. For those
embodiments that disclose a specific value or condition for an
aspect, supplementary embodiments exist that are otherwise
identical, but that specifically exclude the value or the
conditions for the aspect.
* * * * *