Note: Descriptions are shown in the official language in which they were submitted.
C~oss-Referenc~e to ReZated AppZi~ations
The subject matter of the present application is
related to the following U. S. patents issued to Joseph C.
Balch: Reissue 26,387l granted May 7, 1968; 3,472,314,
issued October 14, 1969; 3,648,767, issued March 14, 1972;
and 3,908,753, issued September 30, 1975.
Ba~kground of the Invention
Field of the Invention
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This invention relates generally to heating and
cooling systems, and more particularly, but not by way of
limitation, relates to an improved heating and cooling
system utilizing solar, or other energy for a heat source,
and a buried thermal unit for transfe.r of heat to the
earth for storage and subse~uent transfer to a heat pump
which may be reversed, for heating or cooling a structure,
a body of material, or the like.
Description of the Prior Art
For the purpose of saving energy, it has been
suggested that solar energy be collected and stored for
later release and transfer to a structure to be heated.
The storage means susgested usually comprise tanks of water
or brine, or piles of rocks, or the like, through which
fluid heat transfer pipes are run for ultimate transfer
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of heat to the building. Such storage means require a great
deal of space, and are therefore, normally limited in size
and capacity. This also 1imits the amount of time the heat
can be stored, so that frequently the known systems are
inoperative to deliver the required amount of heat.
.,
Summary of ~he .Invention
The present invention contemplates a heating and
cooling system utilizing solar, waste, or other available
heat sources, simpli$ied apparatus for transferring and
storing the heat in the ground, or in other natura:L bodies r
a heat pump installed in a structure, or body of material,
to be heated or cooled, and duct means connecting the heat
pump to a heat transfer unit forming part of the apparatus
buried in the storage area.
It is, therefore, a primary object of the present
invention to provide an improved heating and cooling system
utilizing simpler apparatus and operating much more effi-
ciently than conven'ional solar eneryy systems.
It is another important object of the invention
to provide a heating and cooling system, which is easy to
install, and which has long life, and requires li-ttle or no
maintenance over long periods of time.
It is a further important ohject of the inven-tion
to provide a heating and cooling system utilizing radiant,
or waste energy, and storing such energy in a large, effi-
cient storage medium, and which is operative ~o perform its
a~ ~
heating or cooling function adequately over entire seasons, or
long periods of time, despite excessive varlations in, or even
nearly complete disappearance of the source of radiar~tenergy dur-
ing a lengthy season.
It is a still further object of the invention to pro-
vide an improved method for heating and cooling which includes
the steps of: collec-ting heat from a source, storing said heat
in underground storage means, and conveying heat from said stor-
age means to a heat purnp in an installation to be heated or
cooled.
B~IEF DESCRIPTION OF THE DRAWINGS
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The novel features that are considered characteristic
of the invention are set forth with par-ticularity .in the appended
claims. The invention itself, however, both as to its orgar~ization
and its method of operation, together with additional objects and
advantages thereof, will best be understood from the following
description of specific er~odiments when read in connection with
the accompanying drawings, wherein like reference characters in-
dicate like parts throughout the several figures, and in which:
Figure 1 is a diagrammatic, elevational view of a
heating-cooling system according to the invention, which utilizes
the earth as a heat storage means and a solar collector as a source
of heat energy;
Fig~re 2 on the third page of drawings is a diagrammatic,
elevational view, partly in section, of a typical thermal cell, for
earth burial, forming part of the system of Figure l;
Figur~ 3 is an enlarged, diagrammatlc elevational view of
the solar collector and connected apparatus;
r~
Figure 4 is a top plan view of the wind tur.bine of
Fig. 3;
Figure 5 iS an enlarged diagrammatic, ele~ational view of
the diaphragm fluid pump of Fig. 3;
Figure 6 on -the fifth page of drawings is a reduced
sectional view along lines 6-6 of Fig. 5, looking in the direction
of the arrows;
Figure 7 on the fifth page of drawings is a view similar
to Fig. 6 but showing the pump cam rotated 180;
Figure 8 is an enlarged diagrammatic perspective view
of the heat pump of Fig. l and connected apparatus;
Figure 9 is a view similar to Fig. 2, but showing a mod-
ified thermal cell for earth burial; and
Figure 10 is an enlaryed, exploded perspective v.iew
of the upper heat transfer jacket of the cell shown in Fig. 9.
DESCRIPTION OF THE BASIC
PREFERP~ED EMBODIMENTS
As shown in Fig. l, the preferred embodiment of
a heating-cooling system according to the invention includes
a source of heat, such as solar collector 10, connected by
ducts to one or more thermal cell units 12, buried under-
gro~md as a heat reservoir, and which are in turn connected to
a heat pump 14 ins-talled in a building 16, for heating,
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d
or cooling r thereof.
The thermal cell unit 12, as best illustrated in
Fig. 2, is ~uite similar in structure to the temperature
control tubes fully described in patents 3,472,314 and
3,678,717, there being however structural improvements, and
variations in the mode of use, mode of functioning, and
connections to accessory apparatus. Thermal cell unit 12
comprises an elongated pipe 20 of metal or other suitable
material, which is entirely buried under the earth surface
22, Fig. 1 and filled through a filler opening, normally
closed by cap 24, to a level shown at 26, with a refrigerant
medium 28 having a low freezing and a high boiling tempera-
ture, such as ethylene glycol mixed with water, alcohol and
water, brines, alcohol and brine, or a large number of
petroleum based products, such as gasoline, or jet fuel.
Centrally of tube 20 is disposed a generally horizontal baffle
plate 30, of molded plastic, molded rubber, or metal, which
separates fluid 28 into upper and lower temperature zones,
or compartments, between which the fluid circulates by con-
vection. To this end the ba~le 30 has a pair of openings
in which are fitted an upstanding riser pipe 32 and a down-
wardly projecting drop tube 34, the former extending to a
level near the top, and the latter to a level near the bottom
of tube 20. The pipes 32 and 34 ~nay be formed of plastict
metal or other suitable materials. Warmer fluid 28 in the
bottom portion of tube 20 will rise following arrows A,
enter riser 32, and exit into upper compartment of tube 70.
Cooler fluid 28 in the upper compartment will descend,
following arrows B, enter drop tube 34, and exit into the
lower compartment. Thus a circulation of fluid 28, arising
from temperature differences and changes, constantly occurs in
tube 20.
~ pper and lower heat transfer jackets, 36 and 38
respectively, surround and are affixed to the upper and lower
portions of tube 20. These jackets are filled with a fluid,
such as ethylene glycol, and/or water, or an alcohol mixture
with water. The lower jacket 38 is fed warm fluid from the
solar collector 10, or the heat pump 14, through duct 40
opening into the top of the jacket, see arrow C. A return
duct 42, opening to the bottom of jacket 38, carries cooled
fluid from the lower jacket either to the solar collector
or the heat pump. Outlet duct 46 leading from the top of
upper jacket 36 carries warmed fluid to the heat pump, and
inlet duct 48 returns cooled fluid from the heat pump to
the upper jacket. Thus the upper jacket affords a means
for transferring a heated fluid to the heat pump. Correspond-
ing ducts 46a and 48a communicating with the upper jacket are
provided for connecting one or more thermal cell units 12
to each other in parallel, see Fig. 1.
The earth surrounding the thermal cell units 12,
acts as a source of heat as well as a heat sink. When the
temperature of the earth is higher than that of the cell
units, heat passes by conduction and radiation into the unit.
When the temperature of the surrounding earth is lower than
that of the ~mits, or portions thereof, heat passes from
the units to the earth. In this way heat from the solar
collector, and from the heat pump, when the latter is cooling
buildiny 16, passes to the earth to replenish heat previously
removed. Thus the combination of the earth and cell units 12
operates with reverse action, and in a novel manner with re-
spect to the thermal tubes described in patents 3,472,314 and
3,648,767, which function only to remove heat from the earth.
The insulation shield 50 is installed at the time
cells are buried, and functions to slow radiation of heat
stored in the earth. The shield is preferably a styrofoam
panel, but an~ number of foams, plastic or other insulating
materials, compatible with the earth, may be used instead.
For light applications, such as heating and coollny a small
dwelling, the shield may be unnec~ssary, as sufficient heat
will remain stored in the earth for long periods without
the shield.
The solar collector 10, see Figs. 1 and 3-7,
comprises as its major parts a thin corrugated casing 52
forming elongated fluid passageways from inlet ducts ~2
and 102 to outlet duct 40, a wind turbine 54 driving a
diaphragm pump 56, a thermostatic bellows device 58 for
stopping the turbine, and a check valve 60 for preventing
reverse flow when warm fluid is fed from the heat pump
toward the cells 12 and solar collector 10. The collector
casing 52 ma~ be made much smaller than normal solar heat
collection devices, because of the great capacity of the
earth to store the collected heat for long periods of
time. Otherwise the collector casing 52 is conventional
in structure~ The wind turbine 54 functions as a slow-moving
drive device to operate pump 56 and circula-te warm fluid
such as ethylene glycol, from casing 52 through check valve
60, duct 40 to the tops of the lower cell heat transfer
jackets 38, out of the bottoms of jackets 38, through ducts
~2 and back to pump 56.
Wind turbine 54 and thermostatic device 58 are
similarly structured and function in the manner fully
described in U. S. Patent 3,908,753, particularly the Fig. 6
embodiment. Briefly, the wind turbine 54 includes a pair of
opposed, offset, semicircular vanes 62, 62 turned by the
wind and fixed to a dependant shaft 64 and a bottom disc 66
having a notch 68 on its under side. Shaft 64 is journalled
in a bearing 70 passing through cap 72 in pump 56 and has its
lower end passing through an eccentric opening in the cylin-
drical cam 112. The -thermostatic device 58 is supported by
brackets from the inlet 102 of solar collector casing 52,
and includes a bellows 76 having a detent pin 78 protruding
upwardly from its top. Under normal ambient temperatures
or higher temperatures, the bellows 76 is expanded; the detent
pin is lowered, and the wind vanes 6~ are free to turn. How-
ever, under low ambient temperatures the bellows contract,
causing detent pin 78 to enter notch 68 and stop the turbine
from revolving. This o~ course stops p~mp 56 and prevents
further circulation of fluid from solar collector 10 to the
thermal units 12 until the ambient temperature rises suffi-
ciently to remove the pin and restart the circulation of
fluid between the solar collector and the buried thermal
cell units.
.
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The diaphragm pump 56, as best illustrated in
Figs. 5-7, is an impro~ement over the screw type propelling
means, described in U. S. Patent 3,908,753, since it permits
slow pumping operation under very light prevailing breezes,
which with the patented device would be inoperative to
circulate fluid between the solar collector and the buried
thermal units. Pump 56 is housed within an elongated, verti-
cally disposed, tubular casing 80. The casing is closed at
the bottom by disc 82 and at the top by disc 72, both secured
to the casing in any suitable manner. Third and fourth discs
84 and 86 are secured within the casing 80 to form a compres-
sion chamber. Disc 86 has an opening 88 aligned with similar
openings 90, 92 in upper disc 84 and bottom closure 82,
respectively. The cold fluid inlet duct 42 is connected in
opening 92 and the pipe 94, having a ball check valve 96
therein, is connected between openings 92 and 88. Check
valve 96 includes a ball valve which closes in its lowermost
position. Opening 90 in the upper disc is connected by pipe
98, having a check valve 100 therein, to the inlet 102 of
solar collector panel 52. Check valve 100 also houses a
ball valve closed when its lowermost position. Housed between
discs 84 and 86 is a rigid, metal, or other semi cylindrical
support 103 for the resilient diaphragm 104. The diaphragm,
o rubber, or like material, is a tubular sheet surrounding
the support plate and closing the diametricalchord across the
open side of the support so as to form a chamber 106 between
discs 8~ and 86 and communicating with the pipes 94 and 98.
The diaphragm is secured by a series of fasteners 108 to a
10- ~
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vertically disposed semi-cylindrical cam striker plate 110
extending nearly th~ full height between the discs 84 and 86.
A vertically disposed, cylindrical cam 112 is rotatably
supported between discs 84 and 86 and the wind turbine drive
shaft 64 passes vertically through an eccentric opening in
the cam and is fixed to the cam in any suitable manner. The
shaft 64 is journalled in an upper pump bearing and seal block
114 on disc 84, and supported at its bottom in a lower bearing
block 116, fixed to the underside of disc 86.
It will be apparent from the above description,
that when the wind turbine is turning, the drive shaft 64
rotates cam 112 so as to move the curved striker plate 110
alternately between the positions shown in Figs. 6 and 7.
In the Fig. 6 position chamber 106 is at its largest size and
in its suction condition so that the cooled fluid enters the
chamber from pipes 42 and 94 lifting and passing valve 96.
As the cam striker plate 110 moves from its Fig. 6 to its
Fig. 7 position, the chamber 106 is reduced in volume, com-
pressing the fluid therein and forcing the fluid upwardly to
lift ball valve 100 in pipe 98, and to pass into the solar
inlet pipe 102, Fig. 3. Thus while the wind turbine is
turning, even slowly under the influence of very light bxee~es,
pump 56 will circulate fluid between the thermal cell units 12
and the solar collector 10. The fluid warmed in the solar
collector gives up its heat to be stored in the earth at the
thermal units, as previously explained.
The heat pump 14 may be of any conventional type.
A typical heat pump is diagrammed, as installed for heating
structure 16, in Fig. 8. Briefly described, the pump 14 is
connected to a heat exchanger 110 and a circulation pump 112,
and includes an expansion valve 114, recei.ver 116, convector
118, compressor 120, register 122 with fan 124. The heat
exchanger 110 comprises a pip~ loop 126 housing an internal
pipe 128. One end of pipe 126 is connected to ducts 46 and
42, leading to the upper and lower jackets 36 and 38 respective-
ly of the thermal cell units 12, by a manually-operated, two-
way valve 130. The other end of heat exchanger pipe 126 is
similarly connected to ducts 48 and 40 leading to the upper
and lower jackets respectively of the thermal cell units 12,
by another manually operated two-way valve 132. Thus
warmed fluid is brought through pipe 46 to pipe 126 and cir-
culated co~nter-clockwise, as shown by arrow H, the pump 112
forcing the ethylene glycol fluid cooled in exchanger 110 back
through valve 132 and duct 48 to the upper jackets 36 of the
cell units 12. When valves 130 and 132 are manually changed
to close ducts 46 and 48 and open ducts 42 and 40, cooler
glycol fluid from thebottoms of lower jackets 38 is brought
to pipe 126, circulated clockwise and returned through duct
40 to the tops of lower cell unit jackets 38. A motor 134
drives compressor 120 by belt 136. A second belt 138 from
the motor shaft drives fan 124, while a third belt 140 drives
circulation pump 112. The inner heat exchange pipe 128 is
connected by pipe 142 to one side of the compressor and by
pipe 144 to a se.rpentine, finned pipe 146 in the convector
118. The other end of pipe 146 is connected through receiver
116 and expansion valve 114 to the other end of heat exchanger
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inner pipe 128. A refrigerant such as Freon fills pipe 128
and the connected pipes and parts.
The heat pump 14 described above is, except for heat
exchanger 110 and its connections 7 a conventional two-way heat
pump, and includes manually or electrically operated changing
cycle transfer valves and switche~, not shown. Accordingly
when the heat pump 14 is to be used for cooling structure 16,
the motor 134 and the pump 112 are reversed and the flow of
fluids in pipes 126 and 128 of the heat exchanger 110 is
clockwise in ~oth as indicated by arrow C'. Under these
circumstances, and with valves 130 and 132 moved to open
ducts 40 and 42 and close ducts 46 and 48, ethylene glycol is
brought from the tops of lower cell jackets 38 through duct
40, clockwise through pipe 126 and returned to the bottoms of
jackets 38 through ducts 42. During passage -through pipe 126,
heat is transferred to the Freon flowing clockwise through
pipe 128. The warmed Freon is compressed in compressor 120
and expands in pipe 146 of convector 118, absorbing heat from
air being pulled through the convector toward register 122,
50 that cooler air is blown through the register into the
building 16.
From the above description, operation of the
Figure 1 system to both heat and cool a building will be
apparent. Heat imparted to the fluid in solar collecter 10
is circulated thxough duct 40 to lower heat transfer jackets
38 and returned to the collecter through duct 42. Jackets 38
impart heat both to the earth and to fluid in tube 2(). The
earth acts as a heat sink to store heat and to release heat
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transferred from and back to the thermal units 12. From
their upper jackets 36, fluid circulates through pipe 126 of
heat exchanger 110 to warm the Freon in p:Lpe 12~. This warm-
ed Freon in turn is circulated through pipe 146 where heat is
released to air blowing through the register 122. The per-
formance of a heat pump increases in efficiency as the con-
densing and cooling coil temperature approach each other.
Therefore, during the heating cycle, if a warmer source can
be found than the ambient air, an increase in per~ormance can
be expected. As the thermal tubes 12 are buried in the earth,
they achieve a more consistent high temperature than other-
wise could be expected from the ambient air.
The reversal of flow in heat pump 14 and heat
exchanger 110 to accomplish cooling of building 16 has been
adequately described above. It should be noted that during
cooling, ducts 40 and 42 are open to both the heat pump 14
and the solar collector 10. For this reason, one-way check
valve 60 is inserted near the solar collector to prevent
flow of fluid from the heat pump to the collector. As the
wind turbine induced pressure of the fluid passing through
the solar collector is very low compared to the pressure
induced at heat pump 112, the check valve stops the fluid
from flowing from the solar collector while the heat pump
is operating to cool the structure; but, when the heat pump
is not in cooling operation, the circulation is available
from the collector.
The described heating-cooling system is much more
efficient than a conventional system because in common systems,
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using storage tanks filled with heated material such as
water, rocks, or the like, a 2,000 gallon tank would be
about 270 cu~ic feet of storage; on the other hand, a
21 foot thermal tube inserted into the earth at a depth of
30 feet would have not less than 2,500 cubic feet of heat
storage and exchange from the surrounding earth. Thus by
storing heat underground, or in the ground, it is there
for months and not days as in the conventional system. In
some cases one thermal tube may be all that is required
if its base is in warm earth or water of 45,or more,degrees
Fahrenheit. Much depends upon location and soil conditlons.
Wi~h a parallel hook-up of thermal tubes, one can expect
ample heat all winter. It must be understood that with a
proper heat pump the thermal tube could remove enough heat
from the soil to cause permafrost in any of the 50 states
of the United States. In order to pre~ent reezing of the
soil~ heat needs to be replenished, a capability of the
present invention not existing in conventional systems.
Des~ription of the Piyure 9 Em~odiment
In Figs. 9 and 10 ls illustrated a modiied thermal
cell unit 12' which eases the installation in the ground by
enclosing all connecting ducts within the confines of upper
heat transfer jacket 36', thus eliminating the need to dig
holes in the earth for some of the ducts. The upper and lower
jackets 36' and 38' are preferably identical cylindrical tubes.
A disc 150 and equal diameter disc 152 are welded or o-therwise
sealingly secured to the top and bottom of jacket 36'. The
thermal tube 20' constructed as explained for the Fig. 2
embodiment, is passed through central opening 154 in the
cover disc and through opening 156 in the bottom closure disc
and extends down and through jacket 38~ having upper and lower
closures identical to disc 152. Tube 20' is welded or other-
wise sealed in the openings 154, 156 of a:Ll closures through
which it passes. The opening 156 in the closure at the bot-
tom of jacket 38' is filled and sealed by a plug. Cover disc
150 has six spaced openings through which the ducts correspond-
ing to those of the Fig. 2 embodiment pass into jacket 36'.
These ducts are numbered ~0', 42', 46', 48' and ~6b and 48b.
Ducts 40' and ~2' pass through openings in disc 152 at the
bottom of jacket 36' and extend to and through corresponding
openings in disc 152 at the top of lower jacket 38'. The
openings in the bottom closure disc for jacket 38' are plugged
and the central opening in the top closure 150 is capped.
It will be apparent that the modified thermal cell
unit has virtually the same structure and therefore operates
in the same manner as the Fig. 2 embodiment, its advantages
lying in ease of ~abricating, assembly,and installation in
the ground.
The length and diameter of the thermal tube 20 or
20' can vary to extremes. Tests have proven that tubes made
as small as 8 inches long work effectively and tubes as
long as 150 feet operate effectively. Diameters have been
used ranging from 1 inch or less to some units having dia-
meters as much as 60 inches. It is expected tha~ a range of
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of lO feet to 200 feet for length with a 2 to 12 inch diameter
of the thermal tube would cover the majority oE applications.
A standard tu~e is expected to be maae out of 2 inch diameter
tubing with ~ inch diameter jackets.
The depth of burial of the thermal cell unit depends
upon the soil conditions. A standard tube is expected to be
about 21 feet in length. The top would be ~uried about 3 or
4 feet below the earth's surface, well below frost lines.
In the Figure 2 embodiment, tubes 32 and 34 are
normally made of polyethylene plastic pipe and are made of
double wa]l pipe for insulation beneflt of a small air space.
For tubes longer than ~0 feet a metal pipe with a ~oam plastic
insulatiorl is desirable.
It is preferable that all duct pipes connecting the
thermal unit transfer ~ackets to the heat pump and solar
collector be double walled with an air space between pipes,
or have an outer wall of insulating material to prevent heat
losses from the ducts.
Considering the above description of -the structure
and operation of the heating-cooling system, it should be
obvious that it is not necessary to install nearly as large
or nearly as many solar collectors as in conventional systems,
and that alternative heat sources can be utilized, such as
the surfaces of roadways, walkways, parking lots, roof sur-
faces, walls, fences, etc. It is estimated that, for example,
a one acre asphalt parking lot having plastic pipe installed
near its surface and being in direct sunshine would absorb
ample heat to replenish the earth with enough heat in two days
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to supply a 10lOOO square foot structure with heat for a
month or more in any of the northern tier states.
Instead of the wind turbine and diaphragm pump,
an electric motor and pump may be used to ciculate fluid
between the heat source (solar collector) and the th~rmal
cell units. While one example of a heat pump has been
describea, other known pumps may obviously be substituted.
The thermal cell units need not be buried in earth, but may
be sunk in hodies of surface or underground water, or bodies
of other materials constituting good heat storage capabilities.
Finally the heat source need not be the sun, as alternatively,
wind, air or exhaust energy may be utili7ed and stored in
the earth.
Evaluation tests indicate that a century of
maintenance-free service can be obtained from the buried
thermal cell units, depending upon proper selection of
materials. It has also been estimated that the present
heating-cooling system requires only expenditure of one
fourth the energy than that of an all electric heating-cooling
system yielding the same output.
Although certain specific embodiments of the
invention have been shown and described, it is obvious -that
many modifications thereof are possible. The invention,
therefore, is not int~nded to be restricted to the exact
showing of the drawings and description thereof, but is
considered to include reasonable and o~vious equivalents.
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