Abstrict A liquid polymer-salt solution as a desiccant in an air conditioning
system comprised of a heat-pipe having its heat absorber section
in an outside air inlet duct following water vapor adsorption into
the desiccant by a contacter section of a dehumidifier, and the
heat-pipe having its heat rejecter section in an exhaust air duct
and preferably preceeding water vapor discharge from the desiccant
by a regenerater section of the dehumidifier.
Claims I claim:
1. An air conditioning system having an outside air inlet duct
and a conditioned air supply duct into a conditioned space, and
an air dehumidifier means for processing a water vapor adsorptive
liquid desiccant including;
a contacter section in the inlet duct for interface contact of
outside air with said liquid desiccant applied thereto by a distribution
means to adsorb water vapor therefrom and thereby weakening the
liquid desiccant,
a regenerater section to remove said adsorbed water vapor from
said weakened desiccant from the contacter section and returned
thereto by said distribution means,
and a heat source means applying heat to the regenerater section
for said removal of adsorbed water vapor therefrom,
the liquid desiccant being a hygroscopic polymer-salt sulfonated
and in solution.
2. The air conditioning system and dehumidifier means as set forth
in claim 1 wherein the liquid desiccant salt is an anionic polymer
containing an element having an atomic weight of 133 and less, sulfonated
and in an aqueous solution.
3. The air conditioning system and dehumidifier as set forth in
claim 1 wherein the liquid desiccant salt is an anionic polymer
containing the element Lithium (Li) having an atomic weight of 6.9
sulfonated and in an aqueous solution as SO.sub.3 Li+.
4. The air conditioning system and dehumidifier as set forth in
claim 1 wherein the liquid desiccant salt is an anionic polymer
containing the element Sodium (Na) having an atomic weight of 23
sulfonated and in an aqueous solution as SO.sub.3 Na+.
5. The air conditioning system and dehumidifier means as set forth
in claim 1 wherein the liquid desiccant salt is an anionic polymer
containing the element Potassium (K) having an atomic weight of
39 sulfonated and in an aqueous solution as SO.sub.3 K+.
6. The air conditioning system and dehumidifier as set forth in
claim 1 wherein the liquid desiccant salt is an anionic polymer
containing the element Calcium (Ca) having an atomic weight of 40
sulfonated and in an aqueous solution as SO.sub.3 Ca+.
7. The air conditioning system and dehumidifier means as set forth
in claim 1 wherein the liquid desiccant salt is an anionic polymer
containing the element Cesium (Ce) having an atomic weight of 133
sulfonated and in an aqueous solution as SO.sub.3 Ce+.
8. An air conditioning system having an outside air inlet duct,
a conditioned air supply duct into a conditioned space, a return
air duct from said conditioned space and a relief exhaust air duct
exhausting return air displaced by outside air and with a blower
means to transport said outside, supply, return and relief air,
and including;
an air dehumidifier means for processing a water vapor adsorptive
liquid desiccant and having a contacter section in the inlet duct
for interface contact of outside air with said liquid desiccant
applied thereto by a distribution means to adsorb water vapor therefrom
and having a regenerater section in the relief air duct for interface
contact of relief exhaust air with weakened liquid desiccant from
the contacter section and applied thereto by a distribution means,
a heat source means applying heat to the regenerater section to
remove water from the liquid desiccant and into the exhaust air,
and a heat-pipe having a heat absorber section in the inlet duct
following said contacter section for removing the heat of adsorption
in the dehumidified air therefrom, and a heat rejecter section in
the relief exhaust air duct ahead of the regenerater section for
applying heat to the regenerater secton to supplement said heat
source means heat application thereto.
9. The air conditioning system and dehumidifier means as set forth
in claim 8 wherein the contacter section is of the packed type
wetted with the desiccant and through which incoming outside air
flows for intimate contact with said liquid desiccant regenerated
and drawn from the regenerater section, heat of regeneration being
removed by heat exchanger means to a cold source.
10. The air conditioning system and dehumidifier means as set forth
in claim 8 wherein the regenerater section is a heat exchanger
in circuit with the heat source means and wetted with weakened water
saturated desiccant from the contacter section and through which
outgoing relief exhaust air flows for intimate contact with said
liquid desiccant to remove water therefrom by means of heat transfered
thereto by the heat exchanger.
11. The air conditioning system and dehumidifier means as set forth
in claim 8 wherein the contacter section discharges weakened water
saturated desiccant through a heat exchanger and to the distribution
means of the regenerater section, and wherein the regenerater section
discharges regenerated heated desiccant through said heat exchanger
and to the distribution means of the contacter section for heat
transfer into and for regeneration of the first mentioned weakened
desiccant.
12. The air conditioning system and dehumidifier means as set forth
in claim 8 wherein evaporative cooling means wets the rejecter
section of the heat-pipe with evaporative liquid for increasing
the cooling effect of the heat absorber section thereof.
13. The air conditioning system and dehumidifier means as set forth
in claim 8 wherein a heat exchanger in the inlet duct ahead of
the contacter section is in circuit with the heat source means to
heat incoming outside air to an optimum range of temperature for
humidification and to deter icing conditions.
14. An air conditioning system having an outside air inlet duct,
a conditioned air supply duct into a conditioned space, a return
air duct from said conditioned space and a relief exhaust air duct
exhausting return air displaced by outside air and with a blower
means to transport said outside, supply, return and relief air,
and including;
an air dehumidifier means for processing a water vapor absorptive
liquid desiccant and having a contacter section in the form of a
heat exchanger in the inlet duct for interface contact of outside
air and wetted with said liquid desiccant applied thereto by a distribution
means to adsorb water vapor therefrom, a regenerater section in
the relief air duct for interface contact of relief exhaust air
with weakened liquid desiccant from the contactor section and applied
thereto by a distribution means,
a heat source means applying heat to the regenerater section to
remove water therefrom and into the exhaust air,
a cooling source means in circuit with the contacter section heat
exchanger to extract heat of adsorption therefrom,
and a heat-pipe having a heat absorber section in the inlet duct
following said contacter section for removing the heat of adsorption
in the dehumidified air therefrom, and a heat rejector section in
the relief exhaust air duct ahead of the regenerater section for
applying heat to the regenerater section to supplement said heat
source means heat application thereto.
15. The air conditioning system and dehumidifier means as set forth
in claim 14 wherein the incoming outside air flows through the
wetted contacter section for intimate contact with said liquid desiccant
regenerated and drawn from the regenerater section, heat of regeneration
being removed by heat exchanger means to a cold source.
16. The air conditioning system and dehumidifier as set forth in
claim 14 wherein the regenerater section is a heat exchanger in
circuit with the heat source means and wetted with weakened water
saturated desiccant from the contacter section and through which
outgoing relief exhaust air flows for intimate contact with said
liquid desiccant to remove water therefrom by means of heat transferred
thereto by the heat exchanger.
17. The air conditioning system and dehumidifier means as set forth
in claim 14 wherein the contacter section discharges weakened water
saturated desiccant through a heat exchanger and to the distribution
means of the regenerater section, and wherein the regenerater section
discharges regenerated heated desiccant through said heat exchanger
and to the distribution means of the contacter section for heat
transfer into and for regeneration of the first mentioned weakened
desiccant.
18. The air conditioning system and dehumifier means as set forth
in claim 14 wherein evaporative cooling means wets the rejecter
section of the heat-pipe with evaporative liquid for increasing
the cooling effect of the heat absorber section thereof.
19. The air conditioning system and dehumidifier means as set forth
in claim 14 wherein a heat exchanger in the inlet duct ahead of
the contacter section is in circuit with the heat source means to
heat incoming outside air to an optimum range of temperature for
humidification and to deter icing conditions.
Description BACKGROUND OF THE INVENTION
This invention relates to air conditioning wherein the intake of
outside air is dehumidified. Heretofore, the desiccants employed
have been expensive and because of their corrosive nature the dehumidifying
section of air conditioning equipment has been fabricated of exceedingly
expensive corrosive resistant materials, for examples calcium chloride
or lithium chloride desiccants employing copper-nickel steel equipment
is the usual requirement. Accordingly, it is a primary object of
this invention to provide a relatively inexpensive and less corrosive
desiccant, and a desiccant that is economically effective and which
is adapted to use in relatively inexpensive equipment made of commercial
grade materials such as steel that is protectively coated as by
a paint or sealant, plating, or galvanizing and the like. It is
cost effective dehumidification which is an object of this invention,
all of which is accomplished without change to the downstream refrigeration
and/or heating equipment.
There are a number of materials known to be useful as desiccants
and particularly polymers proposed to be used as solids adapted
to absorb water and to be regenerated as by drying for repeated
use. However, the use of solid desiccant involves equipment implementation
that can become bulky and oversized due to the nature of volume
increase by the cube of the structural dimensions. With solid polymer
the composition of the desiccant in a substrate is fixed. Therefore,
the water uptake is dependent only upon temperature. However, with
an aqueous polymer solution the liquid concentration can be variable,
so that the water uptake is controllable, since the vapor pressure,
concentration and temperature are all adjustable so as to maximize
their functions. It is therefore an object of this invention to
avoid objectionable size increase in the equipment by employing
liquid polymers which avoid the same as capacity requirements increase,
since they are fluid and are therefore more versatile in their applications.
Such polymers which are feasible to be used as packed desiccants
are:
Polystyrene sulfonic acid sodium salt
Polyacrylic acid ammonium salt
Poly (methacrylic acid) sodium salt
Poly (n-vinylacetamide vinyl sulfonate) sodium salt
Polyacrylic acid sodium salt
Cellulose sulfonate sodium salt
Methyl cellulose
However, it is a liquid desiccant of polymer material with which
this invention is concerned, and to this end it is an object to
provide the same in the form of hygroscopic fluids as a desiccant,
rather than in the form of solid salts.
Water vapor sorption by polymers is a recognized advantage, however
there is criticality involved in the salt to be employed therewith,
the water uptake capability being most important. The ion-dipole
interaction is therefore to be considered, reference being made
to FIGS. 3a, 3b and 3c of the drawings, which illustrate the comparisons
between the use of Lithium, Sodium and Potassium. It becomes apparent
that the Lithium ion Li+ accomodates a far greater amount of water,
of the three, due to to its small cationic size as compared with
either Sodium Na+ or Potassium K+. The atomic weight and corresponding
cationic size of various elements are considered, as follows:
Therefore, it is an object of this invention to employ any one
of the known salts in the sulfonation of the aforementioned polymers
to be employed in a liquid form as a hygroscopic liquid, especially
as a desiccant. Accordingly, Polystyrene Sulfonic Acid Lithium Salt
Solution or PSSALS is a preferred embodiment herein (see FIG. 5b).
It is an object of this invention to implement the advantages of
a polymer-salt solution in dehumidification equipment, as a low
cost unit or section of equipment applicable to existant refrigeration
air conditioning equipment, without major change thereto. Air conditioning
involves generally, an outside air supply, a supply air discharge
into a building interior, return air intake from the building interior,
and a relief air discharge. The polymer-salt solution dehumidifier
of the present invention is adapted to the outside air intake and
to the relief air discharge of the existent air conditioning equipment.
It is an object of this invention to advantageously employ the outside
supply air intake temperature for desiccant treatment. It is also
an object of this invention to advantageously employ a heat-pipe
to extract heat after dehumidification and to dissipate that heat.
The air dehumidifier intake section herein disclosed replaces an
air intake or power section of usual equipment and is preferably
attached to a blower section unit that separates the relief air
from the return air, as shown.
An air conditioning system involves the discharge of relief air
that is replaced by outside supply air. The volume ratio of these
two columns of air varies as a result of variations in leakage from
the conditioned air space involved, the relief air being stale interior
air retrieved at a place or places of higher interior temperature
and where stale air exists. Consequently, relief air is substantially
warmer than supply air (the conditioned air), it being an object
of this invention to advantageously employ warmer relief air before
its discharge as exhaust air, by dissipating its usable heat energy
through the regenerater section of the dehumidifier. It is still
another object of this invention to advantageously employ the heat
energy rejected by the heat pipe, or pipes, for this purpose, as
disclosed in each of the embodiments of this invention as later
described.
In a second embodiment of this invention, FIG. 4 the adsorption
element of the dehumidifier is a heat exchanger over which the polymer-salt
solution is wetted and through which a coolant is circulated for
reduced temperature intake air into the air conditioning equipment.
In practice, the coolant is controlled and circulated by a pump,
over or through a heat exchanger, and chilled or cooled as by means
of an evaporative cooling tower (employing water). The heat-pipe
relationship remains the same as in the first embodiment.
In a third embodiment of this invention, FIG. 6 the adsorption
element of the dehumidifier is the absorber section or hot end of
the heat-pipe and over which the polymer-salt solution is wetted
for water vapor sorption and through which the heat-pipe refrigerant
recirculates for heat absorption. There is a simultaneous heating
effect and cooling effect on the outside supply air, said air being
heated as a result of the water vapor sorption by the polymer-salt
solution while being cooled as a result of heat adsorption by the
hot end of the heat-pipe. It is to be understood that the use of
a hygroscopic desiccant liquid involves regeneration through the
application of heat, which is shown herein generally as a supplemental
heat source, all according with state of the art processes. In accordance
with this invention, regeneration is by means in the discharge of
relief air over the heat rejector section or cold end of the heat-pipe.
In a fourth embodiment of this invention, FIG. 9 a central regenerater
unit services a multiplicity of dehumidifier contactor sections.
That is, a multiplicity of dehumidifier means, each serving an independent
air conditioning unit, commingles weakened desiccant to be strengthened
by a single regenerater section or unit. This combination reduces
the complexity of the dehumidifier means operable with each air
conditioner unit, and makes possible the use of a larger most efficient
regenerater unit for cost efficient operation.
In a fifth embodiment of this invention, FIG. 10 the regenerater
section is a self contained and self operable unit wherein heat
is the prime mover directly applied to the water saturated desiccant
without resort to contact with blower motivated air. Reference is
made to the polymer-salt desiccant solution disclosed herein as
the preferred hygroscopic liquid for the adsorption of water vapor.
This preferred desiccant is known to be more viscous than the usual
prior art desiccant such as Lithium Chloride, and though spray bar
distribution is practical in the contacter section of a dehumidifier
means, regeneration by means of spray bar and interface heat application
presents liquid handling problems, because of the higher viscosity.
It is an object of this invention, therefore, to directly process
the weakened higher viscosity desiccant through a multi effect boiler
concentrater, using the direct application of heat in a first high
pressure stage followed by at least one or more lower pressure stages
and with a counter flow of desiccant from which water vapor is driven
out of the weakened water saturated liquid and returned to the contacter
section or sections as strengthened desiccant.
SUMMARY OF THE INVENTION
A polymer-salt solution is provided as the desiccant in the form
of a hygroscopic liquid that can be processed and transported most
efficienly in cost effective dehumdification equipment. There are
a number of salts that may be used in the formation of the desiccant
provided, prefereably one of small cationic size such as Lithium,
Sodium or Potassium. These polymer materials do not vaporize and
are reasonably stable for the purpose intended, and they are sulfonated
and retained in solution and liquid state for transport between
and effective processing at the contacter section and regenerater
section of the dehumidifier. The preferred desiccant is sulfonated
Lithium, for its small dipole configuration as illustrated in FIG.
3a of the drawings, a cost effective material that is, for example,
approximately two thirds the cost of a comparable aqueous Lithium
Chloride solution, when prepared for the purpose under consideration.
And, by employing a polymer-salt solution as specified herein, corrosive
effect upon the equipment is minimized to the extent that cost effective
materials can now be used in their construction. Accordingly, commercial
grade low cost materials can be used to replace high grade copper-nickel
materials.
The aforesaid employment of polymer-salt solutions for dehumidification
is advantageously combined herein with the function of heat-pipe
means, in a system that has no adverse effect on the outside air
intake to the downstream air conditioning equipment, but rather
a beneficial effect. A feature of this invention is that the dehumidified
air discharge is through heat-pipe means that removes heat added
to the outside intake air in the preceeding process of adsorption.
Another feature of this invention is the use of relief air discharge
over the heat rejecter portion of the heat-pipe means whereby heat
energy in the relief air is advantageously employed and supplemented
by a controllable heat source to operate the regenerater section
of the dehumidifier.
It is still another object of this invention to combine a dehumidifier
and a heat-pipe for simultaneous dehumidification and heat rejection
from outside intake air, ahead of refrigeration or heating by downstream
equipment. In accordance with this invention, the heat absorber
section of the heat-pipe means serves as the adsorption section
of the dehumidifier, its heat transfer surface being wetted with
the desiccant, preferably with the sulfonated Lithium solution as
described. In the summer mode of operation, outside dehumidified
air is pre-cooled. In the winter mode of operation, outside dehumidified
air is permitted to add heat through inherent reversal of the heat-pipe.
The downstream air conditioning equipment operates in either the
summer or winter mode.
The regeneration of weakened desiccant can be conducted on a unit
basis with a regenerater section assigned to each contacter section,
or on a central service basis with a common return to and supply
from a remoted regenerater unit of most efficient design. Further,
a most significant feature of this invention is the higher viscosity
of the polymer-salt solution used as the desiccant, wherein a direct
multi stage boiler regenerater section or unit is most efficient,
thereby eliminating the usual prior art liquid to air interface
contact for vaporization and water vapor discharge.
The foregoing and various other objects and features of this invention
will be apparent and fully understood from the following detailed
description of the typical preferred forms and applications thereof,
throughout which description reference is made to the accompanying
drawings.
THE DRAWINGS
FIG. 1 is a longitudinal side elevation illustrating the system
of the present invention, with the dehumidifier section installed
ahead of a downstream air conditioner.
FIG. 2 is an enlarged diagram showing a first embodiment wherein
a heat-pipe reduces outside intake air temperature and utilizes
the discharge of inside relief air.
FIGS. 3a, 3b and 3c illustrate the comparison in the cationic size
of Lithium, Sodium and Postassium ions, the preferred salts use
herein to form the polymer-salt solution as a desiccant.
FIG. 4 is a diagram similar to FIG. 2 showing a second embodiment,
wherein the adsorption section of the dehumidifier is a heat exchanger
that cools the outside intake air.
FIG. 5a and 5b are diagrams that illustrate Hydrogen and Lithium
anionic polymers, respectively.
FIG. 6 is a diagram similar to FIGS. 2 and 4 showing a third embodiment,
wherein the contacter section of the dehumidifier is combined with
the heat absorber section of the heat-pipe, and with heat rejection
into the relief air that is exhausted through the regenerator section
of the dehumidifier.
FIG. 7 is a perspective fragmentary section of a heat-pipe configuration
as it is employed throughout this disclosure.
FIG. 8 is a sectional view showing the finned feature of the heat-pipe
for efficient heat transfer.
FIG. 9 illustrates a multiplicity of downstream air conditioner
units and each preceeded by a dehumidifier section, and wherein
the multiplicity of dehumidifier sections is serviced by a central
regenerator unit.
And FIG. 10 illustrates a desiccant regeneration multi stage boiler
servicing at least one or more downstream air conditioning systems
or units, and each of which has a contacter section for dehumidifying
incoming outside air.
PREFERRED EMBODIMENTS
Referring now to the drawings, FIG. 1 illustrates typical refrigeration
air conditioning equipment comprised of a power return section 10
a filter section 11 a coil section 12 a blower section 13 and
a diffuser and final filter section 14. The necessary refrigeration
compressor and condenser (not shown) are included in the coil section
12 or they are external. The power section 10 is preferably a blower
section that includes means that separates return air RA into recirculated
supply air SA which is supplemented by incoming outside air OSA
air and into relief air RE which is exhausted to outside atmosphere.
That is, a portion of the conditioned interior air is discharged
as relief air RE, and it is replaced by new incoming outside air
OSA. In practice, the discharge temperature of incoming outside
air OSA into the power return section 10 is proximate to the outside
air temperature, while the discharge temperature of relief air is
that of the warmer interior air. The sections 10-14 discharge supply
air SA into the conditioned interior at a temperature set by thermostat
control means (not shown). The downstream air conditioning equipment
is state of the art, having an intake duct at 15 to receive dehumidified
outside air, and a discharge duct 16 to deliver conditioned supply
air into a building structure. The power return section 10 is in
open communication with the intake duct 15 and receives dehumidified
outside air OAS therefrom. The power section 10 is characterized
by damper means or the like (not shown) that separates a portion
of the return air for discharge to atmosphere via a discharge duct
17 corresponding in capacity to an intake duct 18 (see FIG. 1),
ducts 17 and 18 opening at the interface of power section 10 with
the dehumidifier contactor D and regenerator section R later described.
In accordance with this invention, the structure of the dehumidifier
sections are of commercial grade materials that require the desiccant
to be substantially non-corrosive, and to this end I have provided
a polymer-salt solution in the form of a hygroscopic liquid. As
specified above, there are a number of elements and their atomic
weights to be considered, and among which are the following:
These materials when added to the anionic polymer solutions, as
described herein, will vary in their corrosiveness, it being determined
that some are well within tolerance for contact with commercial
grade materials such as steel that is protectively coated as by
a paint or sealant, plating, or galvanized and the like, without
undue corrosive action. The selected material or element is also
selected for its cationic size (see FIGS. 3a, 3b and 3c), a material
having the smaller ion size being preferable in order to accomodate
a greater number of water clusters in surrounding hydration spheres,
as is illustrated. Accordingly, Lithium Li is preferred, since its
atomic weight and cationic size are very small, and because its
corrosiveness is known to be tolerable when using the commercial
grade materials specified herein. For a comparison, Helium H has
a lower atomic weight of one (1) and therefore a smaller cationic
size, but when sulfonated into a salt solution its corrosive action
is intolerable for a cost effective structure of the type under
consideration.
According to the foregoing, the preferred desiccant is presently
sulfonated Lithium SO.sub.3 Li, PSSALS in a solution and at viscosity
that can be pumped and sprayed within a heat range of 80.degree.
F. to 225.degree. F. db. The sorption properties of this Lithium
polymer-salt solution is substantial and cost effective and provides
a non-vaporizing desiccant that is reasonably stable.
Referring now to the first embodiment and to FIG. 2 of the drawings,
the dehumidifier or contacter section D is a means that involves
both the aforesaid relief air discharge duct 17 and the air intake
duct 18 these two ducts being of substantially the same air flow
capacity, as shown. Discharge duct 17 exhausts relief air RE to
atmosphere at 20 while the separate and essentially parallel duct
18 receives outside air OSA at 21. In accordance with this invention,
there is adsorption means for removal of water from the outside
air OSA flowing therethrough, and there is a heat-pipe means P for
removing heat from the outside air OSA entering through the duct
18 and for rejecting said heat into the relief air RE exhausting
through the duct 17. Accordingly, the heat absorber section 22 of
the heat-pipe means P follows the dehumidifier contacter section
D in the flow of outside air OSA from the entry at 21 to the downstream
discharge at duct 15. And, the heat rejecter section 23 of the heat-pipe
means P preceeds a regenerater section R of the dehumidifier means.
The dehumidifier contacter section D heats the incoming outside
air OSA as a result of the desiccant adsorption of water vapor,
following which said outside air is cooled by the heat absorber
section 22 of the heat-pipe means P. In the first embodiment of
FIG. 2 the dehumidifier contacter section D is of the packed desiccant
wetted type, through which a column of outside air OSA is passed
for intimate contact with the hygroscopic desiccant liquid solution.
A distribution means or spray bar 25 supplied with strong polymer-salt
solution desiccant from a pump 26 wets the pack through which the
air column flows. A sump 27 collects the fall of weak liquid desiccant
from the packing, and from which the desiccant is recirculated to
a regenerater means R by a pump 29. The desiccant supply is subject
to depletion due to evaporation of its water content when operated
in the humidification mode, and it is replenished by a float control
valve 28 supplied with make-up water, as shown.
The regenerater means or section R processes weak moisture laden
desiccant collected by the sump 27 removing the adsorbed water
therefrom, shown herein as a desiccant wetted heat exchanger operated
through the application of heat from a controlled heat source means
32 the pump 29 delivering water laden desiccant thereto by means
of a spray bar 30 or like means. A sump 31 collects the fall of
regenerated liquid desiccant from the heat exchanger and from which
it is returned to the dehumidifier contacter section D via the pump
26. The controlled heat source means 32 is shown in a closed circuit
through the heat exchanger of the regenerater means R, and can be
any suitable heat source such as a boiler or the like. A pump 33
recirculates a liquid heating fluid (water) while applying supplemental
heat as may be required, in addition to the heat rejected into the
relief air RE through the rejecter section 23 of the heat-pipe as
will be decribed. In practice, and for example, heat of compression
can be withdrawn from the refrigeration compressor as by means of
a heat exchanger (not shown), or by any equivalent source of heat
associated with the compressor or section 12.
The heat-pipe means P cools the incoming outside air OSA discharged
by the dehumidifier contacter section D, by absorbing heat therefrom
at its heat absorber section 22 and it heats the outgoing relief
air RE by rejecting heat at its heat rejecter section 23. Accordingly,
the heat absorber section 22 is in the duct 15 following contacter
D while the heat rejecter section 23 is in the duct 17 preceeding
the regenerater section R. The heat-pipe means P is characterized
by a hot end for absorption of heat and by a cold end for rejection
of heat. In other words, there is a "heat in" end and
a "heat out" end, for the normal summer cooling mode,
which is inherently reversed for the normal winter heating mode.
In carrying out this invention, the cold "heat out" rejecter
section 23 is placed in the relief air RE and exhaust duct 17 and
the hot "heat in" absorber section 22 is placed in the
outside air OSA inlet duct 18. A feature of this invention is that
the heat absorber section 22 follows the dehumidifier contacter
section D, while the rejecter section 23 preceeds the regenerator
section R. Accordingly, there is a heat transfer function that occurs
between and from duct 18 to duct 17 so as to reduce the induction
air temperature after dehumidification by the desiccant, and to
increase the relief air RE temperature prior to its employment in
regenerating the desiccant. In practice, transfer of heat energy
from the incoming column of OSA air to the outgoing column of RE
air is by means of a multiplicity of heat-pipe tubes, the cold end
sections 23 in the form of heat dissipaters placed in the duct 17
ahead of the regenerater means and the hot end sections 22 in the
form of heat absorbers placed in the duct 18 following the dehumidifier
means.
In accordance with this invention, the heat-pipes P are lengths
of heat conductive tubing 33 sealed at their opposite ends, having
interior fitting tubular wicks 34 and charged with a fluid refrigerant
35 a temperature responsive liquid-to-gas fluid (see FIG. 7). A
temperature differential between the ends of each pipe causes the
fluid refrigerant to migrate in its liquid state by capillary action
to the warmer end where evaporation to its gaseous state takes place
and thereby absorbs heat. The resultant gaseous refrigerant vapor
then returns through the hollow of the tube, where it gives up the
heat carried thereby, by condensing into the wick in order to repeat
the cycle. The heat transfer process is efficient, since the heat
pipes are sealed and have no moving parts, and therefore require
little or no attention. The heat-pipes are finned for most efficient
heat energy transfer.
In accordance with this invention, control of the heat-pipe means
P involves evaporative cooling of the heat rejecter section 23 thereof
as and when required, to increase the cooling effect of the heat
absorber section 22. As shown, a spray bar 36 supplied with an evaporative
liquid such as water from a sump 37 by a recirculating pump 38 wets
the finned air contacting exterior of the heat rejecter section
23 of the heat-pipe. In practice, the evaporative liquid is cold
make-up water that has a sensible cooling effect as well as an evaporative
cooling effect. A thermostat 24 senses temperature as a control
means that determines cooling requirements.
Referring now to the second embodiment and to FIG. 4 of the drawings,
the dehumidifier means D' differs from the first embodiment in that
it is of the heat exchanger type through which a coolant is circulated
to reduce the desiccant temperature. The ducting 17 18 20 and
21 remain the same, and the heat-pipe means P is unchanged and operates
as above described, with control by means of sensible and/or evaporative
cooling. In practice, a finned air coil type through flow liquid
contact exchanger is employed, with a cold water inlet 40 from a
cooling tower T, and a return line 41 through a pump 42 to the tower.
Accordingly, the desiccant temperature is controlled and/or reduced
as may be required, as by means of a thermostat 44 that senses temperature
as a control means that determines cooling requirements. Desiccant
is supplied from sump 31 by the pump 26 and the regenerater means
R and heat-pipe means P are all as hereinabove described, so as
to control desiccant temperature as circumstances require.
Referring now to the third embodiment and to FIG. 6 of the drawings,
the dehumidifier contacter section D" differs from the first
and second embodiments in that it is combined with the heat absorber
section 22 of the heat pipe means P. The hot heat absorber end section
22 of the heat-pipe functions as a dehumidifier by being sprayed
with desiccant from a spray bar 45 supplied by a pump 46 drawing
desiccant from the sump 31. The spray bar 45 is vertically disposed
as shown, rather than horizontally as in the first and second embodiments.
Accordingly, the pump 46 replaces the pump 26 a sump 47 replaces
the sump 27 a spray bar 45 replaces the spray bar 25 all as shown
in the drawings. The ducting 171820 and 21 remain the same, and
the heat-pipe means P is the same except for its incorporation with
the dehumidifier D' as hereinabove described. In carrying out this
embodiment, the simultaneous functions of water vapor adsorpton
adding heat, and heat absorbtion into the heat pipe, involves combined
heating and cooling of the desiccant during the process of dehumidification.
In order to complete the required cooling effect, I provide a heat
exchanger 50 in the air supply duct 15 following the contacter
dehumidification step, supplied with cooled water at 51 from the
cooling tower T, and with a return line 52 through a pump 53 to
the tower. The relief exhaust air RE is discharged to atmosphere
from the duct 17 at 20 as shown and above described.
A feature of this invention is the adjusted temperature at the
interface of the dehumidifier contacter section D (D' and D"),
cooling the actively strong desiccant to an optimum range of temperature
conductive to water vapor adsorption. This coolant application moderates
the inherent heat rise that results from water vapor adsorption
in the desiccant when the outside air OSA is in contact therewith.
The second embodiment of FIG. 4 advantageously employs tower water
in the dehumifier contacter section D', a coil or plate type heat
exchanger that uses cold tower water to reduce the temperature at
the interface of the contacter section with the incoming outside
air where water vapor adsorption occurs. In accordance with this
invention the advantage of this feature is also provided in the
first and second embodiment, by utilizing cooled tower water to
lower the temperature of the regenerated desiccant, rather than
lowering the interface temperature with incoming air.
As shown in the first embodiment of FIG. 2 cold water from a coolng
tower T passes through a heat exchanger 55 and is returned to said
tower by a pump 56. This heat exchanger is of the tube or plate
type through which the desiccant supply passes to the contacter
spray bar 25 to reduce the temperature thereof at the interface
of the desiccant with the contacter pad or packing where water vapor
adsorption occurs (applicable to FIG. 4 embodiment).
As shown in the third embodiment of FIG. 6 cold water from a cooling
tower T passes through a heat exchanger 57 and is returned to said
tower by a pump 58. This heat exchanger is of the tube or plate
type through which the desiccant supply passes to the contacter
spray bar 45 to reduce the temperature at the interface of the
desiccant with the finned outside surface of the heat-pipe P. It
is the interface temperature of the heat absorber section 22 of
the heat-pipe that is adjusted or moderated by cooling the desiccant
before it is sprayed onto the contacter fins thereof.
Another feature of this invention is the adjusted temperature at
the interface of the dehumidifier contacter section D, heating the
incoming outside air OAS to an optimum range of temperature to avoid
icing, and to provide heat for humidification when required for
the winter mode of operation. As shown in FIG. 2 of the drawings,
this is accomplished by providing a liquid to air heat exchanger
60 in the duct 18 ahead of the dehumidifier contacter section D,
and supplied with heat from the controlled heat source 32 by a
pump 61 in a closed circuit. This application of heat to the incoming
outside air has its practical application to prevent icing-up conditions
which could be damaging to the dehumidifier means during inclement
winter weather. Typical dry bulb-wet bulb temperatures throughout
an operational system are shown in FIG. 2 of the drawings. For example,
a winter weather condition with outside air OAS at 20.degree./16.degree.
F. will benefit from heat applied through the heat exchanger 60
as shown and described.
Still another feature of this invention, in each embodiment, is
the transfer of heat from the regenerated desiccant and into the
weakened desiccant that is returned to the regenerator section for
strengthening. To this end there is provided a heat exchanger 65
of the tube or plate type through which hot regenerated desiccant
flows via pump 26 to the spray bar means 25 and through which cooler
weakened desiccant flows via pump 29 to the spray bar means 30.
Note that the above described heat exchanger 55 or 57 is in line
between the heat exchanger 65 and the spray bar means 25 or 45
following said heat exchanger 65.
Referring now to the fourth embodiment of air conditioner units
as shown in FIG. 9 of the drawings, a central regenerater unit R
operates to service a multiplicity of/air conditioner units A1-A4
as shown to be the same as the air conditioning equipment hereinabove
described, and each includes a power section 10 a filter section
11 a coil section 12 a blower section 13 and a diffuser and final
filter section 14. And the ducting 15-21 remains the same as above
described. It is the regenerater section R of the dehumidifier means
D that is removed from the exhaust air discharge duct 17 and remoted
as a central service unit (see FIG. 9). Accordingly, only the heat-pipe
P operates in the discharge duct 17 of each air conditioner unit
A1-A4 for the rejection of heat by the rejecter section 23 thereof.
Each dehumidifier section pump 29 returns weakened desiccant to
the central regenerater unit R via a common return line 66 and through
heat exchanger 65 as determined by independent operation of their
respective float controls 28 there being a common supply line 67
from the pump 26 to the spray bar means 25 of each unit A1-A4 (above
described).
It is to be understood that this air conditioning system as disclosed
herein is primarily for refrigeration and dehumidification of outside
air OSA delivered into a conditioned space as supply air SA. However,
a reverse situation is satisfied thereby during winter conditions,
in which case the demand is for heating and humidification of relatively
dry outside air OSA. Accordingly, either or both the dehumidifier
means D and heat-pipe P functions are reversed, so that incoming
outside air is heated and/or humidified by what has been disclosed
hereinabove as a contacter but which can now be operated as a humidifier,
and by the inherent reverse function of the heat-pipe P transferring
heat from section 23 to section 22. The heat-pipe responds to the
external heat differential between its opposite ends. The heat exchange
from exhaust duct 17 to inlet duct 18 will vary, and this preceeds
the heating function of the air conditioning unit that operates
in a heating mode rather than a refrigerating mode.
Referring now to FIG. 10 and the fifth embodiment of a dehumidifier
means and a downstream air conditioner system or multiplicity of
units, a regenerater section R' operates to service the same in
the form of a desiccant regeneration boiler B characterized by pressure
decreasing stages that efficiently drive off the unwanted water
vapor of adsorption or steam discharged as condensation to atmosphere
at low pressure. As shown, a three stage boiler system is provided
that will operate at a coefficient of performance (C.O.P.) of approximately
1.6 through the single application of heat to a first stage boiler
chamber 71 as by a gas burner means 70 operating, for example,
at approximately 40 p.s.i. (or at a heat of vaporization of approximately
934 B.T.U. per Lb.), followed by a second stage boiler chamber 72
operating at approximately 20 p.s.i. (or at a heat of vaporization
of approximately 945 B.T.U. per Lb.), and again followed by a third
stage boiler chamber 73 operating at approximately 20 p.s.i. (or
at a heat of vaporization of approximately 960 B.T.U. per Lb.).
By employing the direct multi stage regneration boiler system as
it is disclosed herein, a coefficient of performance of approximately
(C.O.P.) 1.6 is realized, as compared to the typical prior art C.O.P.
of approximately 0.6.
The first boiler chamber 71 discharges via a line 74 through a
heat recovery coil 75 in the second chamber 72. The chamber 72 discharges
via a line 76 through a heat recovery coil 77 in the third boiler
chamber 73. And, the chamber 73 discharges via a line 78 to atmosphere
through one side of a double bundle heat exchanger 81. A manifold
79 collects the condensed discharge from both lines 74 and 76 and
which is discharged to atmosphere through the other side of the
double bundle heat exchanger 81. The boiler pressures are controlled
by pressure regulating means 74', 76', 78' and the manifold 79 by
regulation means 79'.
As shown, exhaust of low pressure 16.5 p.s.i.) condensation and/or
steam is through the heat exchanger 81 for heat recovery into the
weakened desiccant returned by pump or pumps 29 to the regenerater
section or unit R' via the return line 66. The supply line 67 from
the pump 26 to the spray bar means 25 passes through the heat exchanger
65.
A feature of this boiler system is the counter flow of liquid desiccant
sequentially through the heat exchangers 65 and 81 and through
the boiler discharge coils 77 and 75 for heat recovery before the
application of operating heat by the gas fired means 70. Another
feature is the inherent flow of exhaust condensate and/or vapor
resulting from an efficient (80% or more) heat energy recovery from
the multi stage boiler operation.
Having described only the typical preferred forms and applications
of my invention, I do not wish to be limited or restricted to the
specific details herein set forth, but wish to reserve to myself
any modifications or variations that may appear to those skilled
in the art, as set forth within the limits of the following claims.
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