U.S. patent application number 15/875693 was filed with the patent office on 2018-07-26 for moisture separation system.
The applicant listed for this patent is Carrier Corporation. Invention is credited to Haralambos Cordatos, Yinshan Feng, Parmesh Verma.
Application Number | 20180209670 15/875693 |
Document ID | / |
Family ID | 62906084 |
Filed Date | 2018-07-26 |
United States Patent
Application |
20180209670 |
Kind Code |
A1 |
Feng; Yinshan ; et
al. |
July 26, 2018 |
MOISTURE SEPARATION SYSTEM
Abstract
A moisture separating system includes a first heat pump, a
liquid source in thermal communication with a heat absorption
section of the heat pump, and a source of a gas to be treated. The
system also includes a hydrophilic nanoporous membrane comprising a
first side that receives a flow of gas from the gas source and a
second side that receives a flow of liquid from the liquid
source.
Inventors: |
Feng; Yinshan; (South
Windsor, CT) ; Verma; Parmesh; (South Windsor,
CT) ; Cordatos; Haralambos; (Colchester, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Carrier Corporation |
Jupiter |
FL |
US |
|
|
Family ID: |
62906084 |
Appl. No.: |
15/875693 |
Filed: |
January 19, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62448693 |
Jan 20, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F 2003/1435 20130101;
F24F 3/1423 20130101; F24F 2203/1036 20130101; F24F 3/14
20130101 |
International
Class: |
F24F 3/14 20060101
F24F003/14 |
Claims
1. A moisture removal system, comprising a first heat pump; a
liquid source in thermal communication with a heat absorption
section of the first heat pump; a source of gas; and a hydrophilic
nanoporous membrane comprising a first side that receives a flow of
gas from the gas source and a second side that receives a flow of
liquid from the liquid source.
2. The system of claim 1, wherein the first heat pump includes a
heat rejection section that rejects to heat ambient air.
3. The system of claim 1, wherein the first heat pump includes a
heat rejection section that rejects heat to a water flow path in
communication with a cooling tower.
4. The system of claim 1, wherein the first heat pump is a vapor
compression refrigerant heat transfer circuit, a single phase
refrigerant heat transfer circuit, an electrocaloric heat pump, a
thermoelastic heat pump, or a magnetocaloric heat pump.
5. The system of claim 1, wherein the first heat pump comprises a
vapor compression refrigerant heat transfer circuit that includes a
refrigerant evaporator including a heat rejection side that
receives a flow of liquid from the liquid source.
6. The system of claim 1, further comprising a heat exchanger that
comprises a heat rejection side that receives a flow of the gas,
and a heat absorption side in thermal communication with the heat
absorption section of the first heat pump.
7. The system of claim 6, further comprising a controller
configured to operate the heat exchanger in a sensible heat mode in
which sensible heat is absorbed from the gas by the heat exchanger,
and to operate the hydrophilic nanoporous membrane in a latent heat
mode in which latent heat from the condensation of water is
absorbed by the liquid flowing on the second side of the
membrane.
8. The system of claim 1, wherein the liquid source comprises a
chilled water circulation system that includes said first heat
pump, wherein said water circulation system is in thermal
communication with one or more heat sinks.
9. The system of claim 1, further including a second heat pump
comprising a heat absorption section in thermal communication with
a flow of the gas.
10. The system of claim 9, further comprising a controller
configured to operate the second heat pump in a sensible heat mode
in which sensible heat is absorbed from the gas by the second heat
pump, and to operate the hydrophilic nanoporous membrane in a
latent heat mode in which latent heat from the condensation of
water is absorbed by the liquid flowing on the second side of the
membrane.
11. The system of claim 1, wherein the hydrophilic nanoporous
membrane comprises pores configured to promote capillary
condensation of water vapor from the gas on the first side of the
membrane and transport of condensed water to the second side of the
membrane.
12. The system of claim 1, wherein the hydrophilic nanoporous
membrane comprises pores of less than or equal to 100 nm.
13. The system of claim 1, wherein the hydrophilic nanoporous
membrane comprises an organic polymer.
14. The system of claim 1, wherein the hydrophilic nanoporous
membrane comprises a plurality of hollow fibers.
15. The system of claim 1 wherein the hydrophilic nanoporous
membrane comprises a membrane sheet spiral wound together with a
feed spacer sheet and a filtrate spacer sheet.
16. The system of claim 1, wherein the hydrophilic nanoporous
membrane comprises a plurality of membrane sheets in a stack
alternately separated by a feed spacer sheet or a filtrate spacer
sheet.
17. The system of claim 1, wherein the liquid comprises water.
18. The system of claim 1, wherein the liquid comprises a
desiccant.
19. A method of operating the moisture removal system of claim 1,
comprising flowing from the liquid source on the first side of the
hydrophilic nanoporous membrane and flowing gas from the gas source
along the second side of the hydrophilic nanoporous membrane.
20. The method of claim 19, wherein the system further comprises a
heat exchanger that comprises a heat rejection side that receives a
flow of the gas, and a heat absorption side in thermal
communication with the heat absorption section of the first heat
pump, or the system further comprises a second heat pump comprising
a heat absorption section in thermal communication with a flow of
the gas, and wherein the method further comprises operating the
heat exchanger or the second heat pump in a sensible heat mode in
which sensible heat is absorbed from the gas by the heat exchanger
or the second heat pump, and operating the hydrophilic nanoporous
membrane in a latent heat mode in which latent heat from the
condensation of water is absorbed by the liquid flowing on the
second side of the membrane.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This patent application claims priority to U.S. Provisional
Application No. 62/448,693, filed Jan. 20, 2017, which is
incorporated herein by reference in its entirety.
BACKGROUND
[0002] Moisture can be separated or removed from a gas for various
purposes such as industrial processes or air conditioning.
[0003] For example, conventional vapor compression air conditioning
(VCC) systems generally do not provide direct control of humidity
of conditioned air. However, humidity control is often required,
and is provided with VCC systems by direct expansion of refrigerant
to a temperature below the dew point of the air being conditioned.
This results in removal of moisture from the air by condensation of
atmospheric moisture at the VCC system evaporator. Air flow leaving
the evaporator coils is typically near the refrigerant saturation
temperature for a given suction pressure, which is often colder
than the temperature needed for conditioned air, necessitating
re-heating to provide conditioned air at desired temperature and
humidity levels.
BRIEF DESCRIPTION
[0004] In some embodiments of this disclosure, a moisture
separating system comprises a first heat pump, a liquid source in
thermal communication with a heat absorption section of the heat
pump, and a source of a gas to be treated. The system also includes
a hydrophilic nanoporous membrane comprising a first side that
receives a flow of gas from the gas source and a second side that
receives a flow of liquid from the liquid source.
[0005] In any of the foregoing embodiments, the first heat pump
includes a heat rejection section that rejects heat to ambient
air.
[0006] In any one or combination of the foregoing embodiments, the
first heat pump includes a heat rejection section that rejects heat
to a water flow path in communication with a cooling tower.
[0007] In any one or combination of the foregoing embodiments, the
first heat pump comprises a vapor compression refrigerant heat
transfer circuit that includes a refrigerant evaporator including a
heat rejection side that receives a flow of liquid from the liquid
source.
[0008] In any one or combination of the foregoing embodiments, the
system can further comprise a heat exchanger that comprises a heat
rejection side in that receives a flow of the gas, and a heat
absorption side in thermal communication with the heat absorption
section of the heat pump.
[0009] In any one or combination of the foregoing embodiments, the
liquid source can comprise a chilled liquid circulation system that
includes said first heat pump, wherein said liquid circulation
system is in thermal communication with one or more heat sinks. In
some embodiments, the one or more heat sinks can include the heat
absorption side of the heat exchanger that comprises a heat
rejection side in that receives a flow of the gas, and a heat
absorption side in thermal communication with the heat absorption
section of the heat pump.
[0010] In any one or combination of the foregoing embodiments, the
liquid source can comprise a chilled liquid circulation system that
includes said first heat pump, wherein the liquid circulation
system is in thermal communication with one or more heat sinks. In
some embodiments, the one or more heat sinks can include a heat
exchanger comprising a heat rejection side that receives a flow of
the gas, and a heat absorption side that receives a flow of liquid
from the chilled liquid circulation system.
[0011] In any one or combination of the foregoing embodiments, the
system can further include a second heat pump comprising a heat
absorption section in thermal communication with a flow of the gas.
In some embodiments, the second heat pump can be a vapor
compression refrigerant heat transfer circuit, a single phase
refrigerant heat transfer circuit, an electrocaloric heat pump, a
thermoelastic heat pump, or a magnetocaloric heat pump. The second
heat pump can comprise a second vapor compression refrigerant heat
transfer circuit that includes a refrigerant evaporator in thermal
communication with the flow of gas.
[0012] In some embodiments, the system can further comprise a
controller configured to operate the heat exchanger or the second
heat pump in a sensible heat mode in which sensible heat is
absorbed from the gas by the above-referenced heat exchanger or the
second heat pump, and to operate the hydrophilic nanoporous
membrane in a latent heat mode in which latent heat from the
condensation of water is absorbed by the liquid flowing on the
second side of the membrane.
[0013] In any one or combination of the foregoing embodiments, the
hydrophilic nanoporous membrane can comprise pores configured to
promote capillary condensation of water vapor from the gas on the
first side of the membrane and transport of condensed water to the
second side of the membrane.
[0014] In any one or combination of the foregoing embodiments, the
hydrophilic nanoporous membrane can comprise pores of less than or
equal to 100 nm.
[0015] In any one or combination of the foregoing embodiments, the
membrane can comprise an organic polymer.
[0016] In any one or combination of the foregoing embodiments, the
membrane can comprise an inorganic material.
[0017] In any one or combination of the foregoing embodiments, the
hydrophilic nanoporous membrane can comprise a plurality of hollow
fibers.
[0018] In any one or combination of the foregoing embodiments, the
hydrophilic nanoporous membrane can comprise a membrane sheet
spiral wound together with a feed spacer sheet and a filtrate
spacer sheet.
[0019] In any one or combination of the foregoing embodiments, the
hydrophilic nanoporous membrane can comprise a plurality of
membrane sheets in a stack alternately separated by a feed spacer
sheet or a filtrate spacer sheet.
[0020] In any one or combination of the foregoing embodiments, the
liquid can comprise water.
[0021] In any one or combination of the foregoing embodiments, the
liquid can comprise a desiccant.
[0022] In some embodiments, a method of operating the gas
conditioning system of any one or combination of the foregoing
embodiments comprises flowing liquid from the liquid source on the
first side of the hydrophilic nanoporous membrane and flowing gas
from the gas source along the second side of the hydrophilic
nanoporous membrane.
[0023] In some embodiments where the system can include a second
heat pump or a heat exchanger comprising a heat rejection side that
receives a flow of the gas, and a heat absorption side that
receives a flow of liquid from a chilled liquid circulation system,
the method of operating the system, the method further comprising
operating the heat exchanger or the second heat pump in a sensible
heat mode in which sensible heat is absorbed from the gas by the
heat exchanger or the second heat pump, and operating the
hydrophilic nanoporous membrane in a latent heat mode in which
latent heat from the condensation of water is absorbed by the
liquid flowing on the second side of the membrane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Subject matter of this disclosure is particularly pointed
out and distinctly claimed in the claims at the conclusion of the
specification. The foregoing and other features, and advantages of
the present disclosure are apparent from the following detailed
description taken in conjunction with the accompanying drawings in
which:
[0025] FIG. 1 is a schematic depiction of an example embodiment of
a moisture separation or removal system;
[0026] FIG. 2 is a schematic depiction of a membrane unit;
[0027] FIG. 3 is a schematic depiction of a plate and frame
membrane unit;
[0028] FIG. 4 is a schematic depiction of a spiral wound membrane
unit;
[0029] FIG. 5 is a schematic depiction of a tube in shell membrane
unit;
[0030] FIG. 6 is a schematic depiction of another example
embodiment of another moisture separation or removal system;
[0031] FIG. 7 is a schematic depiction of an example embodiment of
a moisture separation or removal system integrated with a chilled
water circulation system;
[0032] FIG. 8 is a schematic depiction of another example
embodiment of a moisture separation or removal system integrated
with a chilled water circulation system; and
[0033] FIG. 9 is a schematic depiction of an example embodiment of
a moisture separation or removal system integrated with an
additional heat pump.
DETAILED DESCRIPTION
[0034] It has been discovered that the energy and system component
requirements on VCC systems for excess cooling to handle the latent
cooling load and then reheat the air being conditioned can create
inefficiency in the air conditioning process and system.
Additionally, water condensation on metallic heat exchanger coils
can cause corrosion problems, further adding to system design and
fabrication costs as well as requiring additional system
complexity. Alternate humidity removal approaches such as desiccant
wheels loaded with a solid desiccant positioned downstream of a
temperature control unit can be space-consuming, and significant
thermal energy is typically required to regenerate the desiccant,
leading to efficiency reductions. Moreover, because the desiccant
wheel is relatively cumbersome and not easy to install or
uninstall, the capacity and operation of the systems based on
desiccant wheels are generally not modular enough to accommodate a
wide range of operations. Liquid desiccant systems can avoid some
of the physical configuration limitations imposed by solid
desiccant systems by providing the capability to move the liquid
desiccant through a flow loop. However, liquid desiccants (e.g.,
lithium chloride) can be highly corrosive or toxic, or both,
further adding to system design complexity, system cost, and
fabrication costs as well as requiring additional system
maintenance. Also, as with solid desiccants, significant heat
energy is typically required to regenerate the desiccant, reducing
system efficiency.
[0035] With reference now to the Figures in which the same numbers
may be used in different Figures to represent like components, FIG.
1 shows a schematic depiction of an example embodiment of a gas
(e.g., air) conditioning system 10a. As shown in FIG. 1, a liquid
source is provided by a liquid circulation loop 12 driven by pump
14. Liquid in the liquid circulation loop 12 is pumped from tank 16
by pump 14. In some embodiments, such as the embodiment shown in
FIG. 1, circulation of liquid through the membrane element 34 can
be facilitated by vacuum pump 17 in communication with the vapor
space of the tank 16. As further shown in FIG. 1, liquid on the
liquid circulation loop 12 is pumped through conduits 12a and 12b
into thermal communication with a heat absorption section of a heat
pump. In the example embodiment shown in FIG. 1, the heat
absorption section of the heat pump is a heat exchanger 18 that is
an evaporator in a vapor compression refrigerant heat transfer
circuit. However, the type of heat pump is not essential, and the
heat pump can be any type of heat pump including but not limited to
a single phase refrigerant heat transfer circuit, a solid state
heat pump such as an electrocaloric heat pump, a thermoelastic heat
pump, or a magnetocaloric heat pump. Heat pumps of the above or
other types could be graphically represented by a modified FIG. 1
in which components 20, 22, 24, 26, 28, and 30 are not present and
in which 18 represents a heat absorption section of a heat pump
such as any of the above mentioned heat pump types that receives
heat rejected from the liquid in circulation loop 12 for the heat
pump to transfer to a heat sink (not shown). With respect to FIG. 1
as shown, the heat exchanger 18 (also referred to as evaporator 18)
operates as an evaporator in a vapor compression refrigerant heat
pump in which refrigerant is compressed in a compressor 20
pressurizes refrigerant in its gaseous state, which both heats the
fluid and provides pressure to circulate it throughout the system.
The hot pressurized gaseous refrigerant exiting from the compressor
20 flows through conduit 22 to condenser 24, which functions as a
heat exchanger to transfer heat from the refrigerant to a heat sink
such as outside air or to chilled liquid from a chilled liquid
circulation system (not shown), resulting in condensation of the
hot gaseous refrigerant to a pressurized moderate temperature
liquid refrigerant. The liquid refrigerant exiting from the
condenser 24 flows through conduit 26 to an expansion device (e.g.,
an expansion valve) 28, where the pressure is reduced. The reduced
pressure liquid refrigerant exiting the expansion valve 28 flows
through conduit 30 to evaporator 18, which functions as a heat
exchanger to absorb heat from the flowing liquid on the heat
rejection side of the evaporator 18. Gaseous refrigerant exiting
the evaporator 18 flows through conduit 32 to the compressor 20,
thus completing the refrigerant loop.
[0036] On the heat rejection side of the evaporator 18, the liquid
from conduit 12b is cooled, rejecting heat to the refrigerant. The
cooled liquid exits from the evaporator 18 and is directed through
conduit 12c to the membrane unit 34. At the membrane unit 34, a fan
(not numbered) can provide a source of a stream of gas to be
treated 36 (e.g., air such as ambient outdoor air or any process
warm humid air) is introduced to a first membrane side of the
membrane unit 34. In the membrane unit 34, water vapor in the air
36 undergoes capillary condensation and is transported to the
liquid circulation loop 12. For embodiments in which the liquid is
water, a water removal conduit 37 (which can include vacuum
backflow prevention, not shown) can provide for removal of water
from the water circulation loop 12 to balance the addition of
condensate from the membrane unit 34. For embodiments in which the
liquid is a desiccant, techniques known for water removal
desiccants can be utilized instead of the water removal conduit
37.
[0037] The liquid on the liquid circulation loop 12 can be any
liquid that is compatible with the water that is condensed in and
transported through the membrane. In some embodiments, the liquid
compatible with water is fully soluble with water or has sufficient
solubility with water to absorb the amount of condensate
transported from the membrane. In some embodiments, the liquid
comprises water. In some embodiments, the liquid consists of water
or consists essentially of water. In some embodiments, the liquid
comprises a water-soluble organic solvent. In some embodiments, the
liquid comprises water and a water-soluble organic solvent.
Additives such as anti-scale additives, biocides, corrosion
inhibitors, pH buffers, etc., can also be included. In some
embodiments, the liquid can include a desiccant. Liquid desiccants
can include aqueous halide salt solutions such as a liquid
desiccant lithium chloride, calcium chloride, lithium bromide,
alcohol solutions (e.g. triethylene glycol, propylene glycol), or
aqueous chemical agents such as CaSO.sub.4.
[0038] An example embodiment of a basic form of a membrane is
schematically shown in FIG. 2. As shown in FIG. 2, a membrane 38
receives air stream 36 along a first side and a liquid stream 40
from the liquid source conduit 12c on a second side. Water vapor 42
from the air is transported through the membrane 38, where it
condenses through capillary condensation and enters the liquid
liquid stream 40. Water vapor in the air is believed to enter the
pores of the nanoporous membrane where it is exposed to hydrophilic
surface with nano sized radius such that that the formed concave
meniscus in the pores induces condensation at temperatures above
the dew point of the bulk gas outside of the pores. The latent heat
of vaporization released by the condensing water is rejected into
the flowing liquid stream, which exits the membrane unit 34 through
conduit 12d for return to the evaporator 18 where heat from the
liquid is rejected to the heat absorption section of the heat
pump.
[0039] The hydrophilic nanoporous membrane can be formed from
various materials, including organic materials (e.g., polymers) and
inorganic materials. Examples of polymer membranes that can be used
to form the hydrophilic nanoporous membrane include
poly-piperazineamides such as the UTC-60 nanofiltration membrane
supplied by Toray Corp, poly-ether-sulfones, or cellulose acetates.
Additionally, polymers without inherent hydrophilicity can be
rendered hydrophilic by surface treatments. For example, PVDF
(poly-vinylidene fluoride)-based nanofiltration membranes including
surface modification for hydrophilicity are available from Toray
Corp. Examples of inorganic materials include ceramics and other
inorganic materials, such as aluminum oxide (Al.sub.2O.sub.3),
titanium dioxide (TiO.sub.2), nanoporous silicon or silicon dioxide
(SiO.sub.2); and materials based on aluminosilicate minerals
(zeolites). An example of a commercially available inorganic
membrane with 10 nm pore size has a selective layer based on
.gamma.-Al.sub.2O.sub.3 and is supplied by Media & Process
Technology, Inc. Composite materials or combinations of materials
can also be used for membranes, e.g., polymer matrix materials with
dispersed inorganic particles, multilayer membranes comprising
inorganic layer(s) and polymer layer(s), or different sections of a
membrane unit utilizing different types of membrane materials.
Nanoporous materials typically include pores with a range or
distribution of sizes, and the term "pore size" is commonly used in
the membrane industry to specify a nominal single size within a
distribution of pore sizes found in the actual material. Pore size,
along with other parameters such as porosity, pore density or pore
volume can be determined by known techniques such as gas adsorption
of nitrogen using the Brunauer, Emmett and Teller (BET) technique
with the membrane disposed on a gas-impermeable substrate. In some
embodiments, the membranes used herein can include nanopores of
less than 100 nm. In some embodiments, the membranes used herein
can include nanopores of less than 50 nm. In some embodiments, the
membranes used herein can include nanopores of less than 20 nm. In
some embodiments, the membranes used herein can include nanopores
in pore size range with a lower end of 0.5 nm, 1 nm, or 2 nm, and
an upper end of 20 nm, 50 nm, or 100 nm. All possible combinations
of the above-mentioned range endpoints are explicitly included
herein as disclosed ranges. It should also be noted that the
presence of pores outside any of the above ranges is not
excluded.
[0040] Various configurations of membranes can be used for the
membrane unit 34. Several example embodiments of membrane units are
schematically shown in FIGS. 3-5. In FIG. 3, a plurality of
membrane sheets 42 are arranged in a membrane unit 34a with a
plate-and-frame configuration with feed spacers 44 and filtrate
spacers 46 disposed between the membrane sheets to provide flow
passages for flowing air 36 and flowing liquid 40. FIG. 4
schematically shows membrane unit 34b with a spiral-wound
configuration. In the spiral wound membrane unit 34b, a membrane
sheet 42 is spiral wound around itself along with feed spacer 44
and filtrate spacer 46 to form a membrane envelope 48 for the air
flow 36 and a feed flow channel 50 for the liquid flow 40. FIG. 5
schematically shows a membrane unit 34c with a hollow fiber
configuration. As shown in FIG. 5, a plurality of hollow fiber
membranes 52 are disposed inside a housing 54. The configuration
shown in FIG. 5 is that of a tube-in-shell, in this case a
tube-in-tube heat exchanger, but other tube-in-shell configurations
could also be used. As shown in FIG. 5, the flow of air 36 to be
treated is introduced to the internal passages inside the hollow
fiber membranes 52 while the flowing liquid 40 flows through space
inside the housing 54 on the outside of the hollow fiber membranes
52. It should be noted that the flow configurations depicted in
FIGS. 2-5 are of representative example embodiments, and that other
flow configurations are included in this disclosure. For example,
the membrane configuration of FIG. 2 shows a counterflow
configuration for the flow of air 36 and the flow of liquid 40, but
co-flow or cross-flow configurations could also be used. In FIG. 4,
the flow of air 36 is directed circumferentially along the
spiral-wound membrane while the liquid 40 flows axially, but the
liquid 40 could instead be directed circumferentially while the air
36 flows axially. In FIG. 5, a counter-flow configuration is shown
for the flow air 36 and liquid 40, but a cross-flow configuration
could be used in which liquid is introduced along path 40a (through
a bottom port, not shown, in the housing 54), or a co-flow
configuration could be used in which liquid is introduced along
path 40b. In another alternative embodiment to FIG. 5, the hollow
fiber membranes 52 can simply be disposed across an airflow
passageway such as a duct instead of being disposed in a tubular
housing.
[0041] The configuration of the air conditioning system 10a shown
in FIG. 1 is a representative example embodiment, and numerous
variations can be made. Another example embodiment of an air
conditioning system 10b is schematically shown in FIG. 6. The
system shown in FIG. 6 utilizes a different liquid loop
configuration than the system of FIG. 1. As shown in FIG. 6, pump
14 draws liquid from a liquid flow side of membrane unit 34 through
conduit 56a and pumps through conduit 56b into tank 16, which is
pressurized, with a pressure control valve 58 in communication with
a gas space of tank 16. Liquid under pressure from a liquid space
of tank 16 is directed to the heat rejection side of evaporator 18.
Cooled liquid exiting from the heat rejection side of evaporator 18
is directed through conduit 56d and control valve 60 to a liquid
inlet of membrane unit 34. Control valve 60 can be adjusted to
regulate the liquid pressure inside the membrane unit 34.
Condensate removal through conduit 37 can be controlled through
control valve 62 to contribute to maintaining a target pressure in
the tank 16.
[0042] FIGS. 1 and 6 show an air conditioning system with a
dedicated heat pump in thermal communication with a liquid source.
As mentioned above, however, these are example embodiments and
numerous variations can be made. FIGS. 7 and 8 schematically show
systems 10c and 10d in which the liquid source is a chilled liquid
circulation system 64. Chilled liquid circulation systems such as
chilled water circulation systems are commonly used for building
cooling and other thermodynamic processes such as power generation,
chemical manufacturing, and other industrial processes. Although a
desiccant or other water-compatible liquid could be used in the
chilled liquid systems shown in FIGS. 7-8, they are described below
with respect to a chilled water circulation system 64 that can
include one or more heat pumps (not shown) that remove heat from
the water and can optionally include one or more circulation loops
(not shown) where chilled water is brought into thermal
communication with one or more heat sources to absorb heat and be
returned to the chilled water system heat pump(s) for heat removal.
As shown in FIGS. 7 and 8, chilled water is received from a supply
line of the chilled water circulation system 64 and directed
through conduit 66a and control valve 68 to a water inlet of the
membrane unit 34. As with the systems of FIGS. 1 and 6, the water
side of the membrane unit 34 receives condensate from moisture in
the air stream 36 and absorbs heat from the latent heat of
vaporization that is released from the condensation, and exits from
a water outlet of the membrane unit 34 through conduit 66b for
return to the chilled water circulation system 64.
[0043] In some embodiments, the return water flow from the membrane
unit 34 in FIGS. 7 and 8 can be returned directly to the chilled
water circulation system through conduit 66b, optionally assisted
by a pump such as pump 70. In some embodiments, a water removal
sub-system 72 comprising the tank 16, water removal conduit 37, and
control valves 58 and 62 similar to the example embodiment of FIG.
6 can optionally be included in the systems 10c or 10d if it is
desired to remove some or all of the condensate volume before
return to the chilled water recirculation system 64. In some
embodiments, such as shown in FIGS. 7 and 8, the system can include
a heat exchanger 72 with a heat absorption side in thermal
communication with the heat pump(s) of the chilled water
circulation system 64 via the receipt of chilled water through
conduit 66c, and a heat rejection side in communication with a flow
of air 74 to be conditioned. In some embodiments as shown in FIGS.
7 and 8, the flow of air to be conditioned can optionally be
configured so that dried air 75 exiting from the air side of the
membrane unit 34 is directed as inlet air 74 to the heat exchanger
72. In some embodiments (not shown), the flow direction can be
reversed so that cooled air exiting the heat exchanger 72 is
directed as inlet flow to the air side of the membrane unit 34.
[0044] FIGS. 7 and 8 schematically show different example
embodiments for integration of the water return flows of the
membrane unit 34 and the heat exchanger 72 to the chilled water
circulation system 64. In FIG. 7, water from the outlet of heat
exchanger 72 is combined with water flow from conduit 66b pumped
from the membrane unit 34 outlet by pump 70. The combined water
flow is fed to pump 76 through conduit 66d, from where it is pumped
through conduit 66e as return water to the chilled water
circulation system 64. In FIG. 8, water from the outlet of the heat
exchanger 72 is pumped under pressure by pump 78 to ejector 80
where it draws a partial vacuum to draw water from the membrane
unit 34 water outlet through conduit 66b. A combined flow of water
from the membrane unit 34 and water from the heat exchanger 72
flows from an outlet of the ejector 80 through conduit 66e as
return water to the chilled water circulation system 64.
[0045] The system capability for integration of the heat exchanger
such as heat exchanger 72 in thermal communication with the heat
absorption section of the heat pump is facilitated by the
significant heat absorbing capacity of chilled water circulation
systems, but the integration can be accomplished in other systems
as well. For example, a heat exchanger for cooling air could be
configured into the systems of FIG. 1 or 6 with a liquid side in
communication with the liquid flow loop 12 (FIG. 1) or the liquid
flow loop 56 (FIG. 6) in similar fashion to the integration of the
heat exchanger 72 in FIGS. 7 and 8, although sizing of the
components of the vapor compression refrigerant heat transfer
circuit for such systems may not offer optimum economic efficiency.
In an alternative example embodiment, an additional heat exchanger
can be integrated with the system in the form of a heat absorption
section of a second heat pump. Such an example embodiment is
schematically shown in FIG. 9, in which air conditioning system 10e
integrates the components from system 10a (FIG. 1) with a second
heat pump 82. As shown in FIG. 9, the second heat pump 82 includes
similar components to the vapor compression refrigerant heat
transfer circuit of the system 10a, which are numbered the same for
the second heat pump 82. The evaporator 18 of the second heat pump
82 receives a flow of air 84 to be conditioned. In some
embodiments, the flow of air to be conditioned can optionally be
configured so that dried air exiting from the air side of the
membrane unit 34 is directed as inlet air 84 to the heat exchanger
18 of the second heat pump 82. In some embodiments (not shown), the
flow direction can be reversed so that cooled air exiting the heat
exchanger 18 of the second heat pump 82 is directed as inlet flow
to the air side of the membrane unit 34.
[0046] In some embodiments, the systems disclosed herein such as
the systems of FIGS. 1, 6, and 7-9 can include a controller 86. The
controller 86 can be in communication with electrical connections
and circuitry (not shown) or through wireless connections with
various sensors and system devices and equipment such as the
control valves, pumps, fans, compressors, etc. that are controlled
to operate the systems. In some embodiments, the controller can be
configured to operate the system to achieve target thermodynamic
performance parameters. For example, in some embodiments in which
the membrane unit-containing system also includes a heat-absorbing
side of a heat exchanger in thermal communication the air to be
conditioned such as shown in the example embodiments of FIGS. 7-9,
the controller 86 can be configured to operate the system so that
sensible heat is absorbed by the heat exchanger (heat exchanger 72
in FIGS. 7-8 or evaporator 18 of the second heat pump 82 in FIG. 9)
and released latent heat of vaporization from condensation of water
vapor is absorbed by the flowing liquid in membrane unit 34.
[0047] While the present disclosure has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the present disclosure is not limited to
such disclosed embodiments. Rather, the present disclosure can be
modified to incorporate any number of variations, alterations,
substitutions or equivalent arrangements not heretofore described,
but which are commensurate with the spirit and scope of the present
disclosure. Additionally, while various embodiments of the present
disclosure have been described, it is to be understood that aspects
of the present disclosure may include only some of the described
embodiments. Accordingly, the present disclosure is not to be seen
as limited by the foregoing description, but is only limited by the
scope of the appended claims.
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