U.S. patent application number 12/570562 was filed with the patent office on 2010-04-08 for water production system and method with auxiliary refrigeration cycle.
This patent application is currently assigned to ISLAND SKY CORPORATION. Invention is credited to Thomas MERRITT.
Application Number | 20100083675 12/570562 |
Document ID | / |
Family ID | 42073815 |
Filed Date | 2010-04-08 |
United States Patent
Application |
20100083675 |
Kind Code |
A1 |
MERRITT; Thomas |
April 8, 2010 |
WATER PRODUCTION SYSTEM AND METHOD WITH AUXILIARY REFRIGERATION
CYCLE
Abstract
An apparatus and method for condensing water vapor in air to
extract liquid water in which a refrigeration system defines a
closed-loop refrigerant path. The refrigeration system includes a
main portion, a first branch portion and a second branch portion.
The first branch portion and the second branch portion each have an
entrance and an exit in fluid communication with the main portion.
The first branch portion includes a first evaporator operable at a
temperature of at most a dew point of air contacting the first
evaporator to cause liquid water to condense on an exterior surface
of the first evaporator. The second branch portion includes a
second evaporator. A first water vessel is positioned proximate to
the first evaporator for collecting water from the exterior surface
of the first evaporator. A second water vessel is positioned
proximate to the second evaporator for holding water chilled by the
second evaporator. A conduit transports water from the first water
vessel to the second water vessel.
Inventors: |
MERRITT; Thomas; (Hollywood,
FL) |
Correspondence
Address: |
CHRISTOPHER & WEISBERG, P.A.
200 EAST LAS OLAS BOULEVARD, SUITE 2040
FORT LAUDERDALE
FL
33301
US
|
Assignee: |
ISLAND SKY CORPORATION
Hollywood
FL
|
Family ID: |
42073815 |
Appl. No.: |
12/570562 |
Filed: |
September 30, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61102120 |
Oct 2, 2008 |
|
|
|
61184956 |
Jun 8, 2009 |
|
|
|
Current U.S.
Class: |
62/93 ; 62/178;
62/288; 62/291; 62/507 |
Current CPC
Class: |
Y10T 137/7737 20150401;
Y02A 20/109 20180101; Y02A 20/00 20180101; E03B 3/28 20130101 |
Class at
Publication: |
62/93 ; 62/291;
62/288; 62/507; 62/178 |
International
Class: |
F25D 17/06 20060101
F25D017/06; F25D 21/14 20060101 F25D021/14; F25B 39/02 20060101
F25B039/02; F25D 17/00 20060101 F25D017/00 |
Claims
1. An apparatus for extracting water from air, the apparatus
comprising: a refrigeration system defining a closed-loop
refrigerant path, the refrigeration system including: a main
portion; a first branch portion; and a second branch portion, the
first branch portion and the second branch portion each having an
entrance and an exit in fluid communication with the main portion;
the first branch portion including a first evaporator operable at a
temperature of at most a dew point of air contacting the first
evaporator to cause liquid water to condense on an exterior surface
of the first evaporator; the second branch portion including a
second evaporator; a first water vessel positioned proximate to the
first evaporator for collecting water from the exterior surface of
the first evaporator; a second water vessel positioned proximate to
the second evaporator for holding water chilled by the second
evaporator; and a conduit for transporting water from the first
water vessel to the second water vessel.
2. The apparatus according to claim 1, wherein the second
evaporator operates at a temperature less than the ambient air
temperature.
3. The apparatus according to claim 1, wherein the first water
vessel is positioned below the first evaporator to collect the
water dripping from the exterior surface of the first
evaporator.
4. The apparatus according to claim 1, wherein the refrigeration
system further comprises: a compressor in the main portion of the
closed loop refrigerant path; a condenser in the main portion of
the closed loop refrigerant path; a first expansion valve in the
first branch portion of the closed loop refrigerant path; and a
second expansion valve the second branch portion of the closed loop
refrigerant path.
5. The apparatus according to claim 4, further comprising a
refrigerant in the closed loop refrigerant path, the refrigerant
passing sequentially during operation from the compressor to the
condenser, to both of the first and second branch portions in
parallel, thereafter returning to the compressor.
6. The apparatus according to claim 1, wherein the refrigeration
system further comprises an air movement device for moving air over
the exterior surface of the first evaporator.
7. The apparatus according to claim 1, further comprising: a first
sensor, the first sensor being used to determine an amount of water
in the first water vessel; and a switch operable to shut off the
air movement device when the amount of water in the first water
vessel is at least equal to a predetermined amount.
8. The apparatus according to claim 7, wherein the switch is
further operable to shut off the refrigeration system when the
amount of water in the first water vessel is at least equal to the
predetermined amount.
9. The apparatus according to claim 7, further comprising: a second
sensor, the second sensor being used to determine a temperature of
water in the second water vessel; and a switch to activate the
refrigeration system when the temperature of water in the second
water vessel is less than a predetermined temperature.
10. The apparatus according to claim 9, further comprising: a
switch to shut off the refrigeration system when the temperature of
water in the second water vessel is not more than a second
predetermined temperature.
11. The apparatus according to claim 10, wherein the predetermined
temperature substantially equals the freezing temperature of liquid
water.
12. The apparatus according to claim 1, further comprising an
ozonator and an ozone diffuser for purifying liquid water in the
second water vessel.
13. A method of extracting water from air using a water production
system, the water production system including an air movement
device, a first water vessel, a second water vessel and a
refrigeration system having a first cooling element and a second
cooling element, the method comprising: operating the air movement
device to cause air to flow and contact the first cooling element;
operating the refrigeration system to: cause the first cooling
element to have a temperature of at most a dew point of air
contacting the first cooling element during operation; and cause
the second cooling element to have a temperature less than the
temperature of a fluid contacting the second cooling element during
operation; condensing liquid water from the air on an exterior
surface of the first cooling element; collecting the water in the
first water vessel; moving a portion of the water from the first
water vessel into the second water vessel; cooling the water in the
second water vessel using the second cooling element; and shutting
off the air movement device if an amount of water in the first
water vessel exceeds a predetermined amount.
14. The method according to claim 13, further comprising: shutting
off the refrigeration system if a temperature of water in the
second water vessel is not greater than substantially to the
freezing temperature of water.
15. The method according to claim 13, further comprising: resuming
operation of the air movement device if an amount of water in the
first water vessel is less than a predetermined amount.
16. The method according to claim 13, wherein the fluid contacting
the second cooling element is air.
17. The method according to claim 13, wherein the fluid contacting
the second cooling element is water in the second water vessel.
18. A method of extracting water from air using a water production
system, the water production system including an air movement
device, a first water vessel, a second water vessel and a
refrigeration system having a first cooling element and a second
cooling element, the method comprising: monitoring an amount of
water in the first water vessel; monitoring a temperature of water
in the second water vessel; and operating the air movement device
to cause air to flow and contact the first cooling element when the
amount of water in at least one of the first water vessel and the
second water vessel is below a predetermined amount; operating the
refrigeration system to: cause the first cooling element to operate
at a temperature of at most a dew point of air contacting the first
cooling element; cause the second cooling element to refrigerate
the second water vessel; condensing liquid water from the air on an
exterior surface of the first cooling element; collecting the water
in the first water vessel; moving a portion of the water from the
first water vessel into the second water vessel when the amount of
water in the first water vessel exceeds a predetermined amount.
19. The method according to claim 18, further comprising: operating
the air movement device and shutting off the refrigeration system
if a temperature of water in the second water vessel is not greater
than substantially the freezing temperature of water.
20. The method according to claim 18, wherein shutting off the air
movement device reduces a rate of condensation of liquid water on
the first cooling element.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 61/102,120, entitled "Methods and Systems for
Potable Water Production," filed Oct. 2, 2008, and to U.S.
Provisional Application Ser. No. 61/184,956, entitled "Method And
System For Water Recovery From Air Using Combined Receiver And
Water Cooled Condenser," filed Jun. 8, 2009, the entirety of both
of which are incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
FIELD OF THE INVENTION
[0003] The present invention relates generally to production of
water, and more specifically to improved systems and methods for
extracting water from water vapor, for example from the
atmosphere.
BACKGROUND OF THE INVENTION
[0004] Ambient air naturally contains some quantity of water vapor,
so the general atmosphere is a potential water source. Extracting
this water from the surrounding atmosphere presents several
challenges. Other attempts to produce water from atmospheric air
have typically fallen short of the desirable criteria, including
efficiency in the amount of water produced per the amount of energy
used, extracting the greatest possible percent of the moisture
available in the air under local conditions, and producing
acceptable quantities of water at all times of day and in various
weather, seasons, and climates. Therefore, atmospheric water vapor
is an essentially untapped source of greatly needed water supplies
that is potentially available worldwide.
[0005] Refrigeration systems have been known for some time.
Vapor-compression cycle refrigeration systems are most common
today, but other types of refrigeration are possible including gas
absorption and heat pumps. A refrigeration system may provide one
or more closed-loop circuits for a refrigerant medium. If the
refrigeration system uses a vapor-compression cycle, it may include
a compressor, evaporator, expansion valve, and condenser.
[0006] Diagrams of an example vapor compression refrigeration
system, and its thermodynamic operation, are shown in FIGS. 10-12.
For example, a compressor may compress a refrigerant from a
saturated vapor state to a superheated vapor state. A condenser may
then remove the superheated condition from the refrigerant vapor,
and then condense the refrigerant to a saturated liquid state.
Across an expansion valve, the refrigerant may become mixed states
of liquid and vapor. And an evaporator may convert the refrigerant
back to saturated vapor. During this cyclical process, an external
surface of the evaporator will become cold. Some form or variation
of this process may be used in refrigerators, freezers, and air
conditioning systems.
[0007] Most refrigeration systems have some cooling element,
through which air passes to shed heat and reach a lower
temperature. In a vapor compression cycle refrigeration system, the
cooling surface of the cooling element will be an exterior surface
of the evaporator. An evaporator having a temperature of at most a
dew point of air contacting the evaporator will cause liquid water
to condense on an exterior surface of the evaporator.
[0008] Whenever this cooling element has a temperature at or less
than the local dew point of the air, water vapor in the air will
tend to condense into droplets of liquid water. When a cooling
element has a temperature at or less than the freezing point of
water, such as in a freezer, water vapor in the air will tend to
condense and then freeze into ice.
[0009] In most residential and commercial refrigeration systems,
this condensation is considered undesirable, and some refrigeration
systems even have features for ameliorating them. However, the
principles causing such condensation can be used to produce liquid
water from water vapor in atmospheric air.
[0010] Exemplary methods of water production and accompanying
apparatus are described in U.S. Pat. No. 6,343,479, entitled
"Potable Water Collection Apparatus" which issued on Feb. 5, 2002,
and U.S. Pat. No. 7,121,101, entitled "Multipurpose Adiabatic
Potable Water Production Apparatus And Method" which issued on Oct.
17, 2006, the entire contents of both of which are incorporated by
reference.
[0011] These patented methods and devices present viable means of
extracting liquid water from atmospheric air, including apparatus
for transforming atmospheric water vapor into potable water, and
particularly for obtaining drinking quality water through the
formation of condensed water vapor on surfaces maintained at a
temperature at or below the dew point for a given ambient
condition. The surfaces upon which the water vapor is condensed are
kept below the dew point by a refrigerant medium circulating
through a closed fluid path, which includes refrigerant evaporation
apparatus, thereby providing cooling of air flowing through the
device, and refrigerant condensing apparatus to complete the
refrigeration cycle.
[0012] Water production systems also suffer from the drawback in
which the refrigeration system operates in an "all or nothing"
manner such that trying to keep the produced water cool also
results in the extraction of additional water from the atmosphere.
The result is that operation of the compressor for a system whose
water collection vessel is full will result in overflow of the
vessel or that the system cannot be operated to keep the collected
water cool. Neither is a desirable result or situation.
[0013] It is desirable to provide a water production system with
different operating modes, to customize operation of the water
production system and its refrigeration system.
SUMMARY OF THE INVENTION
[0014] The present invention advantageously provides a system,
device and method for extracting water from air using a
refrigeration system having different operating modes for
customized operation of the water production system and the
refrigeration system.
[0015] In accordance with one aspect, the present invention
provides an apparatus for extracting water from air in which a
refrigeration system defines a closed-loop refrigerant path. The
refrigeration system includes a main portion, a first branch
portion and a second branch portion. The first branch portion and
the second branch portion each have an entrance and an exit in
fluid communication with the main portion. The first branch portion
includes a first evaporator operable at a temperature of at most a
dew point of air contacting the first evaporator to cause liquid
water to condense on an exterior surface of the first evaporator.
The second branch portion includes a second evaporator. A first
water vessel is positioned proximate to the first evaporator for
collecting water from the exterior surface of the first evaporator.
A second water vessel is positioned proximate to the second
evaporator for holding water chilled by the second evaporator. A
conduit transports water from the first water vessel to the second
water vessel. In accordance with another aspect, the present
invention provides a method of extracting water from air.
[0016] In accordance with another aspect, the present invention
provides a method of extracting water from air using a water
production system in which the water production system includes an
air movement device, a first water vessel, a second water vessel
and a refrigeration system having a first cooling element and a
second cooling element. The air movement device is operated to
cause air to flow and contact the first cooling element. The
refrigeration system is operated to cause the first cooling element
to have a temperature of at most a dew point of air contacting the
first cooling element during operation and to cause the second
cooling element to have a temperature less than the temperature of
a fluid contacting the second cooling element during operation.
Liquid water is condensed from the air on an exterior surface of
the first cooling element. The water is collected in the first
water vessel. A portion of the water is moved from the first water
vessel into the second water vessel. The water in the second water
vessel is cooled using the second cooling element. The air movement
device is shut off if an amount of water in the first water vessel
exceeds a predetermined amount.
[0017] In accordance with still another aspect, the present
invention provides a method of extracting water from air using a
water production system in which the water production system
includes an air movement device, a first water vessel, a second
water vessel and a refrigeration system having a first cooling
element and a second cooling element. An amount of water in the
first water vessel is monitored, and a temperature of water in the
second water vessel is monitored. The air movement device is
operated to cause air to flow and contact the first cooling element
when the amount of water in at least one of the first water vessel
and the second water vessel is below a predetermined amount. The
refrigeration system is operated to cause the first cooling element
to operate at a temperature of at most a dew point of air
contacting the first cooling element and to cause the second
cooling element to refrigerate the second water vessel. Liquid
water is condensed from the air on an exterior surface of the first
cooling element. The water is collected in the first water vessel.
A portion of the water is moved from the first water vessel into
the second water vessel when the amount of water in the first water
vessel exceeds a predetermined amount.
[0018] A more complete understanding of the present invention, and
its associated advantages and features, will be more readily
understood by reference to the following description and claims,
when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A more complete understanding of the present invention, and
the attendant advantages and features thereof, will be more readily
understood by reference to the following detailed description when
considered in conjunction with the accompanying drawings
wherein:
[0020] FIG. 1 is a diagrammatic side view of an exemplary water
production system, constructed in accordance with the principles of
the present invention;
[0021] FIG. 2 is a diagrammatic side view of an exemplary water
production system, constructed in accordance with the principles of
the present invention;
[0022] FIG. 3 is a diagrammatic side view of an exemplary water
production system, constructed in accordance with the principles of
the present invention;
[0023] FIG. 4 is a partial perspective view of an exemplary water
production system constructed in accordance with the principles of
the present invention;
[0024] FIG. 5 is a partial perspective view of an exemplary water
production system constructed in accordance with the principles of
the present invention;
[0025] FIG. 6 is a diagrammatic top view of the exemplary water
production system of FIG. 4;
[0026] FIG. 7 is a diagrammatic side view of the exemplary water
production system of FIG. 4;
[0027] FIG. 8 is a partial exploded view of refrigeration system
components of an exemplary water production system, constructed in
accordance with the principles of the present invention;
[0028] FIG. 9 is a partial exploded view of refrigeration and
structural components of an exemplary water production system,
constructed in accordance with the principles of the present
invention;
[0029] FIG. 10 is a psychrometric chart of water, showing the
physical properties of moist air at sea level;
[0030] FIG. 11 is a representative diagram of temperature and
entropy for an exemplary refrigerant; and
[0031] FIG. 12 is a representative diagram of a known refrigeration
system.
DETAILED DESCRIPTION OF THE INVENTION
[0032] The present invention advantageously provides an improved
system and method for extracting water from water vapor, for
example from the atmosphere. The water production system of the
present invention may have various sizes, arrangements and
features.
[0033] Some aspects of the present invention relate to combinations
of components and method steps for implementing systems and methods
to improve the efficiency and operation of water production
systems. Accordingly, some components have been represented where
appropriate by conventional symbols in the drawings, showing only
those specific details that are pertinent to understanding the
embodiments of the present invention, so as to avoid details that
will be readily apparent to those of ordinary skill in the art
having the benefit of this description.
[0034] Relational terms, such as "first" and "second," "top" and
"bottom," and the like, may be used solely to distinguish one
entity or element from another entity or element, without
necessarily requiring or implying any physical or logical
relationship or order between such entities or elements.
[0035] Referring to the drawings, various embodiments of water
production devices are illustrated. The illustrations of course
depict only some of many different possible designs that are within
the scope of the present invention. In particular, the present
invention encompasses water production systems having numerous
combinations of elements, and the description of any element also
contemplates providing more than one of that element. For clarity
and convenience, the present detailed description will only
describe a few specific embodiments of the present invention.
[0036] An apparatus for extracting water from the water vapor in
atmospheric air may generally include a refrigeration system having
a cooling element and a subcooler, with a water basin for
collecting water as it condenses on the cooling element, in which
the subcooler is submerged. The cooling element has a temperature
of at most a dew point of air contacting the cooling element, so
that liquid water condenses on an exterior surface of the cooling
element.
[0037] The refrigeration system may be of various types, including
vapor-compression cycles, gas absorption and heat pumps. Regardless
of which type of refrigeration system is chosen, the refrigeration
system should have at least one cooling element, with an exterior
cooling surface. During operation, the cooling surface is
maintained at a temperature which is at or less than a dew point of
air. In other words, atmospheric air flowing through a water
production system can contact a cooling element of a refrigeration
system having a temperature of at most the dew point, to cause
liquid water to condense on a cooling surface.
[0038] An example water production system may include for example,
a first and second cooling element, and a first and second water
vessel. The first water vessel may be positioned proximate to the
first cooling element for collecting water condensing on its
exterior surface. The second water vessel may be positioned
proximate to the second cooling element for holding water chilled
by the second evaporator. A conduit may also be provided for
transporting water from the first water vessel to the second water
vessel. According to some of the principles of the present
invention, an apparatus and method may be used to optimize water
production, which may include maintaining a desired amount of
chilled potable water.
[0039] With specific reference to the drawings, in which like
reference designators refer to like elements, an exemplary diagram
of a water production system is shown in FIG. 1, and is generally
designated as "10." In this particular illustrated example, water
production system 10 has a refrigeration system 12, which may be of
any suitable type, and may have various arrangements of
refrigeration components. If the refrigeration system is of the
vapor-compression type, it may include for example at least one
compressor, evaporator, expansion valve, and condenser. The
refrigeration system may provide one or more closed-loop circuits
for a refrigerant medium.
[0040] In the diagram of FIG. 1 for example, a refrigeration
circuit may be arranged from a compressor 20, to a first condenser
22, to a second condenser 24, to an optional subcooler 14, to an
expansion valve 26, to an evaporator 28, and back to the compressor
20. A refrigerant medium may proceed in a closed-loop path around
the components and conduits of the refrigeration system.
[0041] For example, a refrigerant in a saturated liquid state may
cross expansion valve 26, becoming mixed states of liquid and
vapor. Evaporator 28 may then convert the refrigerant back to
saturated vapor. An external surface of the evaporator 28 may
accordingly be cooled to a temperature at or below the local
ambient dew point of air, which will tend to cause liquid water to
condense from water vapor in the air. The resulting cooled liquid
water will tend to condense and fall from the evaporator 28, into
water basin 16.
[0042] Continuing a refrigeration cycle description, the compressor
20 may then compress refrigerant from a saturated vapor state to a
superheated vapor state. The first condenser 22 may then remove the
superheated condition from the refrigerant vapor, thus acting as a
de-superheater. The second condenser 24 may then condense the
refrigerant to a saturated liquid state. Then, subcooler 14 of the
present invention uses water in the water basin 16 to further cool
the saturated liquid refrigerant. The subcooler 14 may thus serve
as a reservoir for liquid refrigerant until needed, based on demand
through the expansion valve.
[0043] Passing the tubing of the subcooler through water transfers
heat from the refrigerant inside the subcooler by conduction, and
by some water flow through the water basin into the water
collection vessel, rather than merely by convection alone with the
air. Also, water in the water basin will tend to have a temperature
lower than the ambient air temperature, having fallen from
condensation in contact with the cooler external surfaces of the
evaporator. Accordingly, the water in the water basin is even more
effective than ambient air, for example, to cool the refrigerant
inside the subcooler.
[0044] The subcooler may have various desired arrangements, such as
for example a conduit or tube having any suitable shape, including
straight, curved, undulating, convoluted, sinusoidal, coiled,
spiral, etc. The subcooler may also have either a two-dimensional
or three-dimensional shape or pattern. If desired, a subcooler may
have bends that are smooth and arcuate, to facilitate flow of
refrigerant through it. Also, it may be desirable to provide a
convoluted shape of some kind, to maximize the external surface
area of the subcooler in contact with water in the water basin.
Such a larger surface area will tend to consequently maximize heat
transfer from the refrigerant inside the subcooler to the water in
the water basin. Accordingly, a subcooler may increase efficiency
of the refrigeration system, and lower operating costs of the water
production system.
[0045] The water basin may also be fitted with a mechanism for
maintaining a desired amount of water in the water basin, so that
the subcooler remains submerged. Such a water-level maintaining
mechanism may have any suitable configuration, including a
float-actuated device, servo mechanism, or the illustrated example
of a drain tube 32. Drain tube 32 may be arranged vertically, with
an inlet port 34 inside the water basin at an elevation or a
vertical position above the subcooler, and an outlet port 36
opening above the water collection vessel 18.
[0046] Accordingly, water basin 16 will tend to initially fill with
water until the level reaches the elevation of the drain tube 32
inlet port, which is vertically positioned to completely submerge
the subcooler in water. Additional water will then tend to drain
into the inlet port 34, through drain tube 32, exiting from outlet
port 36 and into water collection vessel 18.
[0047] As indicated by the arrows in FIG. 1, air flow may be
provided to or by the water production system, passing through the
refrigeration system and particularly through the evaporator and
condensers. Of course, the air flow may be natural or forced, with
or without an air movement device such as a fan.
[0048] Another embodiment of the present invention may provide one
or more additional refrigeration systems. For example, a water
production system may include more than one refrigeration
system.
[0049] For example, the water production system shown in FIG. 2
provides a first and second refrigeration system, each arranged in
a similar fashion and defining separate closed-loop refrigerant
paths. The two refrigeration systems include two compressors 38 and
40, two matching pairs of evaporators 58, 60, 62 and 64, two
water-cooled subcoolers 50 and 52, two pairs of expansion valves
54, 55, 56, and 57, and two pairs of condensers 42, 44, 46 and 48.
An air movement device such as a fan 66 may be used to cause air
flow, for example in the direction of the arrows in FIG. 2.
[0050] An example cold water refrigeration circuit of a potable
water collection apparatus, constructed in accordance with the
principles of the present invention, is described with reference to
FIG. 3. The particular embodiment shown in FIG. 3 depicts an
exemplary water production system for extracting potable water from
the atmosphere, including a compressor 124, a first condenser 68
and a second condenser 70, a water-cooled subcooler 72, an
expansion valve 74, and one or more evaporators 76. First condenser
68 may be provided to perform the role of a de-superheater. A
housing 78 may include an air inlet 80 and an optional air bypass
inlet 82, into which ambient air may be pulled by way of a fan 84.
The air may then be evacuated at an exit opening in the housing 78
where the fan 84 is generally positioned. The amount of bypass air
introduced into the housing 78 through the air bypass inlet 82
relative to the air flowing into inlet 80 may be controlled and
modulated by a valve or damper 86. In one embodiment, damper 86 may
be operated by a stepper motor, servo, or other controller, which
in turn may be manually controlled or coupled with a
microcontroller to cause the operation and adjustment of damper 86
based on environmental or other conditions.
[0051] The optional bypass inlet 82 and the associated damper 86
may be physically located between the condenser 70 and the
evaporator 76. At lower temperatures, the damper may be closed,
thereby allowing more air to flow over evaporator 76. At higher
temperatures, the damper 86 may be opened, allowing more air over
condensers 68 and 70 in comparison to the amount of air flowing
over evaporator 76. Less air flowing over evaporator 76 means a
lowering of the temperature of the refrigerant in evaporator 76.
With damper 86 open, the needed air pressure may drop to about 8
pounds per minute, requiring less energy to operate. If the
dimensions of bypass air inlet 82 are made larger relative to air
inlet 80, the required air pressure may be able to be lowered to
approximately 5 pounds per minute.
[0052] Air entering housing 78 through air inlet 80 passes through
evaporator 76 and then de-superheater 68 or condenser 70.
Evaporator 76, de-superheater 68 and condenser 70 operate as known
in the art based on the flow of refrigerant through the
refrigeration components. Air entering housing 78 through air
bypass inlet 86 passes through de-superheater 68 or condenser 70,
and bypasses evaporator 76.
[0053] The refrigerant flow of the present invention may be
described as follows. Refrigerant is compressed by compressor 124
and flows through a conduit to de-superheater 68 and then condenser
70, where it collects in water-cooled subcooler 72. This portion of
the refrigeration system may be referred to as a main portion. The
refrigerant then flows through thermostatic expansion valve 74 and
through evaporator 76. This portion of the refrigeration system may
be referred to as a first branch portion. Thermostatic expansion
valve 74 is controlled by temperature sensing bulb 88. Temperature
sensing bulb 88 is in contact with the suction line after the
evaporator 76, and measures the temperature of the refrigerant
leaving evaporator 76. As the temperature of evaporator 76
increases, more refrigerant is needed to effect the extraction of
the water from the air by maintaining or lowering the surface
temperature of the evaporator 76. As the temperature of the
refrigerant exiting evaporator 76 increases, the pressure in
temperature sensing bulb 88 increases, thereby exerting pressure on
a diaphragm inside the expansion valve 74, which in turn allows
increased refrigerant flow through expansion valve 74. This action
allows the surface of evaporator 76 to be maintained below the dew
point of ambient air at a wide range of ambient air temperatures.
In operation, air flowing through the evaporator 76 gives up its
heat, thereby causing water vapor within the air to condense on the
surface of evaporator 76 and fall into a collecting tray 90.
[0054] Water-cooled subcooler 72 allows additional refrigerant to
be stored within the refrigerant path, such that it is readily
available for use when conditions require additional refrigerant as
noted above. By maintaining collected water in collecting tray 90,
water-cooled subcooler 72 is submerged in water that has been
recently condensed, and cooled to a temperature at or near to the
temperature of evaporator 76. Water at this cooler temperature
increases the efficiency of the water-cooled subcooler.
[0055] The refrigerant flow also includes a path through an
auxiliary evaporator 92 via a second expansion valve 94. In
operation, this allows some compressed refrigerant to bypass around
the evaporator 76, thereby flowing through auxiliary evaporator 92.
This portion of the refrigeration system may be referred to as a
second branch portion. Auxiliary evaporator 92 may have any
suitable shape, including coiled, undulating or convoluted, and
surrounds chilled water vessel 96. Water inside chilled water
vessel 96 is thereby cooled, and the evaporated refrigerant enters
compressor 124 to begin the refrigeration cycle again.
[0056] The water extracted from ambient air flows through the water
production system shown in FIG. 3 as follows. Water collects in
collecting tray 90, and a drain tube 98 may be arranged within
collecting tray 90. Accordingly, after the water rises to a
predetermined level that is sufficient to submerge the water-cooled
subcooler 72, additional water drains through drain tube 98 and
into a water tank 100. An ozone diffuser 102 is supplied with ozone
by an ozonator 104, to ozonate the water in water tank 100, which
tends to purify it.
[0057] When a primary water collection vessel 100 is full, a
thermistor or other temperature sensor 216, which senses
temperature in chilled water vessel 96, may signal a first switch
or controller 220 to turn on compressor 124, and may signal a
second controller 218 to turn off an air movement device such as a
blower or fan 84. When the fan 84 is off, a first and second
evaporator 76 and 92 are under a decreased load, thereby lowering
the pressure and temperature of the refrigerant within the
refrigerant circuit. The compressor 124 sends the refrigerant to
the second evaporator 92 at a cold water vessel 96 to chill the
water. The use of the sensor 216 to control the blower 84 allows
the dual use of the water-making components to provide
refrigeration for the chilled water vessel 96 when the primary
collection vessel 100 is full.
[0058] When the primary water vessel 100 is full, float switch 214
may shut off the water-producing apparatus so that water is no
longer produced, but a refrigeration mode or "chilling cycle" is
enabled. During this chilling cycle, sensor 216 in the secondary
vessel 96 signals the first controller 220 to run the compressor
124, and signals the second controller 218 not to run the fan 84.
The result is that the secondary evaporator 92 chills the secondary
water vessel 96 without the first evaporator 76 producing more
drinking water.
[0059] Any suitable type of sensor may be used. For example, a
first sensor may be provided to determine an amount of water in the
primary water vessel, and a switch may shut off the air movement
device when the amount of water in the first water vessel is at
least equal to a predetermined amount. This predetermined amount
may be equal to that which fills the primary water vessel, or
another suitable amount. The switch may also shut off the
refrigeration system when the amount of water in the primary water
vessel is at least equal to the predetermined amount.
[0060] The sensor 216 may send a temperature indication to a
controller, e.g., a microprocessor, which determines the
appropriate time to turn the compressor on or off, as well as when
to turn the blower 84 off. This control allows the water-producing
apparatus to chill the water without freezing the water and/or any
refrigeration components. For example, when the apparatus is in a
water-producing mode, the blower 84 and the compressor 124 are both
on. However, when the apparatus is operating to refrigerate the
water, the compressor 124 is on, but the blower 84 is off.
[0061] The controller may also cycle the blower between on and off
while chilling the water to ensure that when water is dispensed, it
is subsequently replaced by ambient water. A second sensor may also
be provided to determine an amount of water in the primary
collection vessel 100 or the second water vessel 96, and a switch
may then activate both the refrigeration system including the
compressor 124 and the air movement device or fan 84, when the
amount of water in a water vessel is at most equal to a
predetermined amount. This predetermined amount may be
approximately equal to a water vessel being empty, or another
suitable amount such as for example half of a water vessel's
capacity.
[0062] Temperature sensor 216 may be provided to monitor the
temperature of water in the chilled water vessel 96, such that when
it falls below a predetermined threshold, the controller also turns
the compressor 124 off to ensure that the water does not freeze.
This predetermined threshold temperature may be substantially equal
to the freezing temperature of liquid water, or may be another
temperature.
[0063] A pick-up tube 106 is positioned within water tank 100, such
that water can be extracted from water tank 100 and pumped by a
water pump 108 into chilled water vessel 96, through a filter 110,
and out either a cold water faucet 112 or a hot water faucet 114.
Filter 110 can be, for example, a charcoal filter. Water destined
for hot water faucet 114 is first collected in a hot water vessel
116 and heated by a heater 118. Heater 118 may be an electric
heater controlled by a thermostat (not shown).
[0064] As is shown in FIG. 3, the water path of the water
production system also includes a return path back to water tank
100 through water return line 120 and valve 122. Valve 122 may be a
solenoid or other electrically-operated valve. When there is little
or no demand for water from the cold water faucet 112 and hot water
faucet 114, valve 122 may be opened so that water may be circulated
by water pump 108 from water tank 100, through chilled water vessel
96 and back into water tank 100. This recirculation facilitates the
ozonating process and resists bacteria formation in the plumbing
lines from water tank 100 to the faucets 112 and 114. Valve 122 can
be controlled by a microcontroller or other processor which
monitors water demand, for example, by monitoring the water
pressure on the outlet side of the pump 108. Other arrangements for
monitoring the water pressure to thereby control the valve 122 are
also contemplated, and of course the invention is not limited
solely to the arrangement described above.
[0065] Water production systems of the present invention may also
provide an air duct with one or more ports, including an entry port
and an exit port. An air movement device may be a fan disposed
within the air duct, operable to draw air through the air duct.
[0066] If a specific embodiment defines an air duct, an
intermediate port may be provided between the entry port and exit
port, such that the air duct defines a first and second air flow
path. The first air flow path may proceed sequentially through the
entry port, evaporator, condenser, and exit port. In contrast, the
second air flow path may proceed sequentially through the
intermediate port, condenser, and exit port, thus bypassing the
evaporator. In other words, with the intermediate port being
positioned between the evaporator and condenser, air can enter the
air duct: (i) through the entry port and evaporator, and (ii)
through the intermediate port, bypassing the evaporator. The air
movement device in such embodiments is capable of moving air
through the air duct along the first and second air flow paths.
[0067] For example, FIGS. 4-9 depict a water production system
defining a rectangular air duct having entry ports, intermediate
ports, and exit ports. The exit port is positioned at one end of
the air duct, and the fan is positioned near the exit port. Water
production systems according to the present invention may have one
or more bypass ports that remain open, or may be selectively opened
and closed, either in a binary or selectively adjustable fashion.
The water production system 200 of FIGS. 4-9 has four intermediate
ports 202a-d (referred to collectively herein as "intermediate port
202") defined on the top between each of four evaporators 204a-d
(referred to collectively herein as "evaporator 204") and four
condensers 206a-d (referred to collectively herein as "condenser
206"), and at least four additional intermediate ports 208a-d
(referred to collectively herein as "additional intermediate port
208") are defined on both sides of each pair of evaporators 204 and
condensers 206. A corresponding set of four water-cooled subcoolers
210a-d (referred to collectively herein as "subcooler 210") are
positioned within four water basins 212a-d (referred to
collectively herein as "water basin 212"), and below each
evaporator 204.
[0068] While conventional refrigeration systems may be optimized
for cooling the air in a chamber, water production systems are
optimized for production of water. Accordingly, one or more
water-cooled subcoolers of the present invention may be desirable
to increase the efficiency of the water production system.
[0069] In embodiments having more than one evaporator and
condenser, it may also be desirable to connect the evaporators to
the refrigeration system in parallel, and yet connect the
condensers to the refrigeration system in series. In this case, the
refrigeration system may be arranged to cause the refrigerant to
exit the first condenser in a gaseous state, and to exit the second
condenser in a liquid state, such that the first condenser acts as
a de-superheater.
[0070] Water production systems of the present invention may also
be provided with an ice sensor capable of sensing ice buildup on an
evaporator, and a switch coupled with the ice sensor to shut off
the refrigeration system when ice is present, with the air movement
device remaining in operation.
[0071] In operation of the water production systems of the present
invention, a method of extracting water from air may include, for
example, providing an air duct having an entry port, an
intermediate port, and an exit port; providing an air movement
device; and providing a refrigeration system including a cooling
element. The method may also include operating the air movement
device to cause air to flow along a first and second air flow path.
The first flow path may be into the entry port, through the cooling
element, and out the exit port, while the second flow path may be
into the intermediate port, and out the exit port, thus bypassing
the cooling element. The method according to the present invention
may further include operating the refrigeration system to cause the
cooling element to maintain a temperature of at most a dew point of
air contacting the cooling element. The present invention may also
include condensing liquid water on an exterior surface of the
cooling element, and collecting the liquid water.
[0072] In the method of the present invention, a bypass valve may
further be provided, and may also include determining a temperature
of the air, opening the bypass valve when the temperature exceeds a
selected temperature, and closing the bypass valve when the
temperature falls below the selected temperature. The method of the
present invention may also include adjusting one or more bypass
valves in response to a variety of conditions, inputs or sensors,
including for example a thermometer, clock, timer, humidity sensor,
rain sensor, light sensor, etc.
[0073] In a specific example embodiment of the present invention, a
water production system may be provided as shown FIGS. 4-9, with
various components being selected as follows: two matching
refrigeration systems, each having a 5 hp compressor, a pair of
evaporators with an air flow capacity of 100 pounds of air per
minute, a pair of water-cooled subcoolers, a pair of expansion
valves, and a pair of condensers with an air flow capacity of 200
pounds of air per minute. The fan was selected having a capacity of
200 pounds of air per minute, and adjustable bypass valves were
provided with a controller set to open them above an ambient air
temperature selected at 78 degrees Fahrenheit, or 25.6 degrees
Celsius. The resulting example embodiment produced approximately
0.5 liters of water per minute.
[0074] Another embodiment of the present invention may involve
constructing a water production system with tubing and other
components of one or more materials which resist accumulation of
bacteria. Examples may include conduits from a water inlet to a
pump inlet, from a pump outlet to a water chiller component, and
from a chiller component to a water filter. In other words, all
plumbing pieces contacting the collected water may be composed of
tubing which resists contamination, for example HPC bacteria. One
possible material that may exhibit such an advantage is copper, and
using copper tubing may be advantageous.
[0075] Several advantages may be achieved with the present
invention, including for example enhanced efficiency, lowering the
amount of energy used to produce a specific amount of water when
operating the water production system. Another advantage of the
present invention includes broadening the possible environments,
geographical areas, weather conditions, and times of day when the
water production system of the present invention may be used
effectively and efficiently.
[0076] It should be understood that an unlimited number of
configurations for the present invention could be realized. The
foregoing discussion describes merely exemplary embodiments
illustrating the principles of the present invention, the scope of
which is recited in the following claims. In addition, unless
otherwise stated, all of the accompanying drawings are not to
scale. Those skilled in the art will readily recognize from the
description, claims, and drawings that numerous changes and
modifications can be made without departing from the spirit and
scope of the invention.
* * * * *