U.S. patent application number 16/273097 was filed with the patent office on 2019-07-25 for advanced energy recovery ventilator.
The applicant listed for this patent is Xergy Inc. Invention is credited to Bamdad Bahar, Jack Saltwick.
Application Number | 20190226703 16/273097 |
Document ID | / |
Family ID | 67299304 |
Filed Date | 2019-07-25 |
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United States Patent
Application |
20190226703 |
Kind Code |
A1 |
Bahar; Bamdad ; et
al. |
July 25, 2019 |
ADVANCED ENERGY RECOVERY VENTILATOR
Abstract
A composite ion exchange membrane is made by combining ionomer
with porous polyolefin, such as polyethylene or polypropylene. The
composite ion exchange membrane may be used in the core of an
energy recovery ventilator. The core of the energy recovery
ventilator may comprise corrugated or pleated supports for
supporting the composite ion exchange membrane. The air flow into
the energy recovery ventilator may be modified to actively create
non-laminar flow.
Inventors: |
Bahar; Bamdad; (Georgetown,
DE) ; Saltwick; Jack; (Georgetown, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Xergy Inc |
Harrington |
DE |
US |
|
|
Family ID: |
67299304 |
Appl. No.: |
16/273097 |
Filed: |
February 11, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15800398 |
Nov 1, 2017 |
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16273097 |
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PCT/US16/63699 |
Nov 23, 2016 |
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15800398 |
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62258945 |
Nov 23, 2015 |
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62300074 |
Feb 26, 2016 |
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62353545 |
Jun 22, 2016 |
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62373329 |
Aug 10, 2016 |
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62385175 |
Sep 8, 2016 |
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62416072 |
Nov 1, 2016 |
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62629044 |
Feb 11, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F 12/006 20130101;
F24F 11/0008 20130101; F24F 11/30 20180101; G05B 15/02 20130101;
F24F 2003/1435 20130101; C25B 1/10 20130101; F24F 3/147 20130101;
F24F 12/002 20130101; Y02E 60/36 20130101; C25B 9/10 20130101; C25B
13/00 20130101; Y02E 60/366 20130101 |
International
Class: |
F24F 11/00 20060101
F24F011/00; C25B 1/10 20060101 C25B001/10; F24F 12/00 20060101
F24F012/00 |
Claims
1. An advanced energy recovery ventilator comprising: a) a
composite ion exchange membrane comprising: i) a porous polyolefin
support layer having a thickness and comprising a plurality of
pores that extend through the thickness; ii) an ionomer coupled to
the porous support layer; iii) an intake side; iv) an extract side
that is opposite the intake side; wherein the composite ion
exchange membrane is non-permeable, having a Gurley Densometer
reading of at least 500 seconds; b) an intake air inlet for
receiving intake air c) an exhaust air outlet; wherein intake air
enters the intake air inlet, passes by the intake side of said
composite ion exchange membrane and exits the exhaust air outlet of
the energy recovery ventilator as exhaust air; d) an extract air
inlet for receiving extract air; e) a supply air outlet; wherein
extract air enters the extract air inlet, passes by the extract
side of said composite ion exchange membrane and exits the supply
air outlet of the energy recovery ventilator as supply air.
2. The advanced energy recovery ventilator of claim 1, wherein the
extract air is hotter than the supply air.
3. The advanced energy recovery ventilator of claim 1, wherein the
exhaust air is hotter than the intake air.
4. The advanced energy recovery ventilator of claim 1, wherein the
extract air comprises moisture and wherein said moisture in the
extract air is transferred through the composite ion exchange
membrane to the intake air.
5. The advanced energy recovery ventilator of claim 1, wherein the
porous support layer comprises expanded porous polyethylene.
6. The advanced energy recovery ventilator of claim 5, wherein the
ionomer is imbibed into the expanded porous polyethylene.
7. The advanced energy recovery ventilator of claim 6, wherein the
ionomer is imbibed into the pores of the polyolefin layer.
8. The advanced energy recovery ventilator of claim 1, wherein the
support layer is polyethylene.
9. The advanced energy recovery ventilator of claim 8, wherein the
support layer is expanded Ultra-High Molecular Weight porous
Polyethylene.
10. The advanced energy recovery ventilator of claim 1, wherein the
support layer is polypropylene.
11. The advanced energy recovery ventilator of claim 1, wherein the
ionomer is a styrene-based ion exchange ionomer.
12. The advanced energy recovery ventilator of claim 1, wherein the
composite ion exchange membrane is less than 25 microns thick.
13. The advanced energy recovery ventilator of claim 1, wherein the
composite ion exchange membrane is less than 15 microns thick.
14. The advanced energy recovery ventilator of claim 1, wherein the
composite ion exchange membrane is less than 10 microns thick.
15. The advanced energy recovery ventilator of claim 1, wherein the
composite ion exchange membrane is less than 5 microns thick.
16. The advanced energy recovery ventilator of claim 1, wherein the
composite ion exchange membrane comprises corrugations.
17. The advanced energy recovery ventilator of claim 1, wherein the
composite ion exchange membrane comprises corrugations.
18. The advanced energy recovery ventilator of claim 1, wherein the
composite ion exchange membrane is configured in an exchange module
comprising a plurality of flow channels configured from corrugated
composite ion exchange membrane.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of U.S. patent
application Ser. No. 15/800,398, filed on Nov. 1, 2017 and
currently pending, which is a continuation in part of International
Patent Application no. PCT/US2016/063699, filed on Nov. 23, 2016
which claims the benefit of U.S. provisional patent application No.
62/258,945, filed on Nov. 23, 2015, U.S. provisional patent
application No. 62/300,074, filed on Feb. 26, 2016, U.S.
provisional patent application No. 62/353,545, filed on Jun. 22,
2016, U.S. provisional patent application No. 62/373,329, filed on
Aug. 10, 2016 and U.S. provisional patent application No.
62/385,175, filed on Sep. 8, 2016; and U.S. application Ser. No.
15/800,398 claims the benefit of priority to U.S. provisional
patent application No. 62/416,072, filed on Nov. 1, 2016, and U.S.
application Ser. No. 15/800,398 claims the benefit of U.S.
provisional patent application No. 62/629,044, filed on Feb. 11,
2018; the entirety of all applications listed are hereby
incorporated by reference herein.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] This application is a novel composite ion exchange membrane
comprising an ionomer coupled with a porous polymer and
particularly a porous polyethylene or polypropylene, and the use of
this novel composite ion exchange membrane in an energy recovery
ventilator.
Background
[0003] Increased focus on energy efficiency in both for commercial
and residential buildings has led to building envelopes becoming
tighter against airflow into and out of structures. This is
desirable from a heating/cooling standpoint, but requires attention
be paid to ventilation of the space to ensure high indoor air
quality for building occupants; air free from noxious buildup of
volatile organic compounds VOCs (out-gassing carpet, furniture,
etc.) cleaners, particulate (pet dander, dust etc.) and
bioeffluents including carbon dioxide. To minimize the
heating/cooling and (de)humidification costs associated with such
ventilation, Energy Recovery Ventilators (ERVs), as generally show
in FIG. 1, are designed to move heat and moisture between exhaust
and fresh airstreams to pre-condition incoming air. Among various
types of ERVs, fixed-plate ERVs--which transfer heat and moisture
directly from one airstream to another through membranes arranged
in a "core"--are uniquely advantageous in that such devices are
passive (no moving parts), low maintenance, and can demonstrate
negligible leakage from exhaust to fresh airstreams--enabling
energy recovery from a wider range of exhaust air supplies
(including bathroom exhaust) than other types of ERVs. Such
advantages have made fixed-plate ERVs an increasingly popular form
in the market. An analysis conducted with industry
statistics.sup.1,2 market forecast.sup.3, and climate data.sup.4
estimates that total energy savings from fixed plate ERVs over a
20-year operational lifetime is 6.6 Quads. Performance enhancements
will increase the rate of market uptake and energy savings
SUMMARY OF THE INVENTION
[0004] This application describes an advanced ion exchange membrane
for integration into ERVs and redesigning the air-exchange core to
significantly increase the energy recovery of the system. This
system is anticipated to improve performance by at least 23% over
conventional systems, enabling ERV systems to increase their energy
benefit to 7.4 Quads nationally over a 20-year period i.e. energy
savings would increase by 0.8 Quads over current, commercially
available fixed-plate ERV exchangers.
[0005] It should be noted that ERVs, within standard ventilation
systems, provide an opportunity to downsize heating and
air-conditioning equipment due to load reductions by enabled by the
ERV. An improved ERV system would therefore also allow for
significant additional operational cost savings. It should also be
noted that the U.S. market has been poorly penetrated. An improved
ERV core would be transformational and disruptive, enabling
significant expansion of the current market for ERVs by improving
economic payback for buyers. This would yield further energy
savings not captured in our calculations.
[0006] Fixed-plate ERVs are simple devices: exhaust air moves
through a channel formed between two parallel membrane plates and
maintained by a flow-field separator. Immediately opposite the ERV
membrane from the exhaust air, supply air moves through a similar
flow field separator.
[0007] Academic studies suggest that the airside boundary layer can
account for as much as 95% of the overall heat transfer resistance
(5,6). However, analysis of commercially available membrane ERV
exchangers attribute most of the moisture transfer resistance to
the membrane, with airside (boundary layer) moisture transfer
resistance estimated at only 10-35% of the total moisture transfer
resistance (7). To maximize the energy-saving potential of
fixed-plate ERVs, both the airflow dynamics through the membrane
exchanger as well as water permeability characteristics of the
membranes must be improved.
[0008] Over the past 30 years, commercial ERV cores have been
developed for low construction cost, and not for optimized
performance. With much of the U.S. supply coming from overseas,
margins are squeezed, and no-one in the U.S. is in the position to
expend resources to do research to improve performance. Significant
improvements are feasible, yet no single entity can address these
developments without the formation of a consortium and grant
support.
[0009] An exemplary energy recovery ventilator may be used in a
wide variety of applications including, a desiccator, such as for
an ionic liquid desiccant, as a component of a sensor, as a
component of used in electrolysis, as a component of a battery, as
a component of an ultracapacitor, as a component of an
electrochemical compressor, or a pervaporation device.
[0010] The summary of the invention is provided as a general
introduction to some of the embodiments of the invention, and is
not intended to be limiting, Additional example embodiments
including variations and alternative configurations of the
invention are provided herein.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0011] The accompanying drawings are included to provide a further
understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention, and together with the description serve to explain
the principles of the invention.
[0012] FIG. 1 shows a perspective view of an exemplary energy
recovery ventilator
[0013] FIG. 2 shows a perspective view of an exchange module of an
exemplary energy recovery ventilator having a pleated transfer
medium forming flow channels.
[0014] FIG. 3 shows diagrams of exemplary air twisters for an
ERV.
[0015] FIG. 4 shows a cross-sectional diagram of an exemplary
composite ion-exchange membrane
[0016] FIG. 5 shows a graph of water permeance vs. projected
materials cost for various polymer membranes
[0017] FIG. 6 shows a graph of water permeability vs. ion exchange
capacity for styrene-based ion exchange resins.
[0018] FIG. 7 shows the chemical structure of an exemplary novel
styrene-based ion exchange resin structure, with maximum ion
exchange capacity (IEC) of up to 6.2 meq/g.
[0019] The figures represent an illustration of some of the
embodiments of the present invention and are not to be construed as
limiting the scope of the invention in any manner. Further, the
figures are not necessarily to scale, some features may be
exaggerated to show details of particular components. Therefore,
specific structural and functional details disclosed herein are not
to be interpreted as limiting, but merely as a representative basis
for teaching one skilled in the art to variously employ the present
invention.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0020] As used herein, the terms "comprises," "comprising,"
"includes," "including," "has," "having" or any other variation
thereof, are intended to cover a non-exclusive inclusion. For
example, a process, method, article, or apparatus that comprises a
list of elements is not necessarily limited to only those elements
but may include other elements not expressly listed or inherent to
such process, method, article, or apparatus. Also, use of "a" or
"an" are employed to describe elements and components described
herein. This is done merely for convenience and to give a general
sense of the scope of the invention. This description should be
read to include one or at least one and the singular also includes
the plural unless it is obvious that it is meant otherwise.
[0021] Certain exemplary embodiments of the present invention are
described herein and are illustrated in the accompanying figures.
The embodiments described are only for purposes of illustrating the
present invention and should not be interpreted as limiting the
scope of the invention. Other embodiments of the invention, and
certain modifications, combinations and improvements of the
described embodiments, will occur to those skilled in the art and
all such alternate embodiments, combinations, modifications,
improvements are within the scope of the present invention.
[0022] Non-permeable, as used herein, is defined as a material
having greater than a 500 second Gurley Densometer reading, as
measured using an automatic Gurley Densometer 4340, from Gurley
Precision Instruments, Inc., Troy, N.Y.
[0023] As shown in FIG. 1, an exemplary energy recovery ventilator
10 utilizes a composite ion exchange membrane 60 to transfer heat
and humidity from extract air 30 to intake air 20. The intake air
20 enters through an intake air inlet 40 and flow past the intake
side 66 of the composite ion exchange membrane before exiting
through the exhaust air outlet as exhaust air 24. The exchange air
30 enters through the extract air inlet 50 and flows past the
composite ion exchange membrane before exiting through the supply
air outlet 54 as supply air 34. Heat and/or humidity are exchanged
through the composite ion exchange membrane from the exchange air
to the intake air. This system may be a low cost way to keep air
fresh in a room or to reduce humidity in an enclosed space.
[0024] As shown in FIG. 2, the composite ion exchange membrane may
be configured into an exchange module 80 having flow channels 82
formed from pleats 70 of the composite ion exchange membrane 60. A
flow channel may be formed on one side by the pleated composite ion
exchange membrane and on the opposing side by a flat sheet layer 84
of the composite ion exchange membrane.
Core Design
[0025] The core of an energy recovery ventilator may have pleated
or corrugated supports for the transfer medium, or ion exchange
membrane, as shown in FIG. 2.
Airflow Design
[0026] A twister 90 or 90', as generally shown in FIG. 3 may create
turbulent flow through the energy recovery ventilator which may
enhance exchange through the composite ion exchange membrane. A
twister comprises a plurality of elongated members that extend into
the flow of the intake air and/or extract air.
[0027] As shown in FIG. 4, a composite ion exchange membrane 60
comprises a porous polyolefin 62 and an ionomer 64. The porous
polyolefin acts as a support layer for the ionomer and has pores
that extend through the thickness. The ionomer may be coated on one
or both sides of the porous polyolefin layer and/or may be imbibed
into the pores of the porous polyolefin, as shown. The composite
ion exchange membrane 60 has an intake side 66, exposed to the
intake air, and an extract side 68, exposed to the extract air. The
thickness 67 of the composite ion exchange membrane 60 may be very
low, such as no more than about 50 microns, no more than about 25
microns, no more than about 15 microns, no more than about 10
microns and even no more than 5 microns, and any range between and
including the values provided. The thinner the composite ion
exchange membrane, the more transfer of heat and humidity through
the layer.
New High-Performance Membranes
[0028] Ion exchange membranes, typically used for electrochemical
applications, demonstrate the properties required for an enhanced
ERV membrane. High water permeances (2.00.times.10.sup.-8 kg
s.sup.-1 m.sup.-2 Pa.sup.-1, FIG. 5) can be achieved with both
cation-exchange membranes (such as commercially-available
perfluorosulfonic acid (PFSA) membranes) and novel anion exchange
membranes, typically used for fuel cells. Traditional ion exchange
resins are prohibitively expensive (generally, a bare minimum of
$50/m.sup.2 when cast into a composite membrane suitable for
ERVs).
[0029] Other ion exchange materials exist that demonstrate similar
water transport properties to fuel cell membranes while being based
on less expensive, commodity chemicals. For example, sulfonated
polystyrene or sulfonated styrene-ethylene-butadiene (SEBS)
copolymers offer high water permeance (2.00.times.10.sup.-8 kg
s.sup.-1 m.sup.-2 Pa.sup.-1) at a low (approx. $5/m.sup.2) cost
(FIG. 5). These materials are currently in use for ERV
applications. However, none of them have ion exchange capacity
(IEC) greater than 2.5 meq/g. There is a correlation between IEC
(the degree to which the polymer is functionalized) and water
permeability (the thickness-independent property of a material to
transport water) (FIG. 6). With new synthesis techniques, ion
exchange resins based on commodity SEBS polymers can be produced
with an IEC up to 6.0 meq/g (FIG. 7), more than twice that of
commercially-available resins. Although these copolymers retain
some mechanical strength, they do need to be `composited` i.e.
combined with a thin, porous support layer, to improve dimensional
stability and provide additional mechanical reinforcement in
operation.
[0030] One key element of this advanced composite material is the
use of porous polyethylene or polypropylene as the support matrix
versus expanded polytetrafluoroethylene (ePTFE) as patented by W.
L. Gore and Associates. Polyolefins are more suited to many
Non-fluorinated ionomers--such as SEBS, but also advanced
phenyls-based systems as patented by Rensselaer Polytechnic
Institute and University of Delaware. Porous Polyolefins can be
produced in a number of different ways which is more commonly used
as a separator for lithium-ion batteries. Its use as a base for
composite ion exchange media is novel. These materials can be made
via solvent extrusion or an expansion process similar to the
production of ePTFE, by using Ultra-high-molecular-weight
polyethylene (UHMWPE) i.e., producing a compressed puck from
powders, then pultruding through a die (with temperature, and
solvent) and then subsequent expansion to stretch out the pultruded
film to many times the width of the slot die. Because they are not
perfluorinated substrates, the physical compatibility of the
ionomers and solutions is improved with these alternates
substrates.
Novel Core Construction
[0031] Without fundamental changes in core design and construction,
advanced membranes cannot operate to their full potential. It is
well known that traditional construction methods employed to build
ERV cores use corrugated triangular spacers between membrane sheets
to enable air flow. This is a low cost, simple approach that
provides for essentially-laminar flow across the membrane. To
reduce resistance due to boundary layer formation in ERV cores, the
present invention contemplates the integration of `air twisters`
into the ERV core right at the inlet to air (see attached
photograph). The degree of rotation (turbulence, as expressed by
measured Reynolds number), the length of the air twisters, and
overall width of the air slot are important parameters that must be
optimized to obtain optimum energy recovery. A schematic of this
design is provided.
[0032] The ionomer may be a styrene based ionomer or ion exchange
material, as shown in FIG. 7, and may have a maximum exchange
capacity of up to 6.2 meq/g.
REFERENCES
[0033] The entirety of all references listed below are hereby
incorporated by reference herein.
[0034] 1. AHRI. Confidential Reports: Air-to-Air Energy Recovery
Ventilation Equipment. 2017.
[0035] 2. Confidential Reports: Air-to-Air Energy Recovery
Ventilation Equipment. 2016.
[0036] 3. MarketsandMarkets. Energy Recovery Ventilator
Market--Global Forecast to 2021. 2016.
[0037] 4. Engineering Weather Data. [CD] Asheville, N.C.: National
Climatic Data Center, 2000.
[0038] 5. Zhang LZ, Niu J L., Energy requirements for conditioning
fresh air and the long-term savings with a membrane-based energy
recovery ventilator in Hong Kong.Energy2001;26:119-35.
[0039] 6. Jason Woods, Membrane processes for heating, ventilation,
and air conditioning, Renewable and Sustainable Energy
Reviews33(2014)290-304
[0040] 7. Heat transfer and pressure drop in spacer-filled channels
for membrane energy recovery ventilators. Jason Woods, Eric
Kozubal. 2013, Applied Thermal Engineering, pp. 868-876.
[0041] It will be apparent to those skilled in the art that various
modifications, combinations and variations can be made in the
present invention without departing from the spirit or scope of the
invention. Specific embodiments, features and elements described
herein may be modified, and/or combined in any suitable manner.
Thus, it is intended that the present invention cover the
modifications, combinations and variations of this invention
provided they come within the scope of the appended claims and
their equivalents.
* * * * *