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The present invention relates to a device for the collection of solar heat
energy, and is particularly concerned with improvements in effeciency in
solar heat collection devices and in the method of making such devices and
in constructing and utilizing such devices.
Devices for collecting solar heat energy have been known and experimented
with for a long time. Heretofore, the devices have been relatively
expensive to construct and have proved to be relatively inefficient and,
in general, have not been satisfactory.
With the foregoing in mind, the present invention proposes the construction
of a device for collecting solar energy in which the drawbacks referred to
above are eliminated.
BRIEF SUMMARY OF THE INVENTION
The solar heat energy collector of the present invention comprises one or
more units with each unit comprising a body of material which is formed of
a translucent or transparent plastic which may, for example, be an acrylic
resin. It is also possible to use glass. Other materials will suggest
themselves, with the material, in every case, being relatively transparent
to solar radiation and capable of prolonged exposure to the elements
without significant deterioration.
The body of material forming a single unit includes a top wall, a bottom
wall and a peripheral wall and extending therebetween a central web
parallel to the top and bottom walls and including therein a plurality of
side by side fluid passages. Manifolds at each end of the unit communicate
with the passages to form the means for causing fluid flow into and out of
the passages with the fluid collecting solar heat energy from sunlight
passing through the top wall of the unit, and through the fluid confining
wall directly into the fluid. Efficiency of the device derives from
heating the fluid directly without heating the collecting device.
Each unit is preferably mounted in a frame which confines the unit from
beneath and laterally while exposing the top wall thereof while being
formed of a material which either conducts heat poorly or which is
insulated against heat flow outwardly from the unit.
Each frame may be tiltably supported so that the unit therein can be
presented with the top wall in a frame substantially perpendicular to the
sunlight falling thereon, or may be conventionally supported.
It is advantageous for the unit to be formed by an extrusion process with
the ends of the unit being closed after the extrusion has been made. An
extrusion of the nature referred to might, for example, be three to about
six feet in width and can be formed in suitable lengths.
When the collector is in operation, light sensitive detectors carried by
the frame cause automatic tilting of the frame so that the collector will
follow the sun as the earth rotates while fluid is caused to flow through
the passages in the unit, either by pumping means or by convection. The
heated fluid withdrawn from the collector can be stored or delivered to
points of use.
As many collectors as might be desired can, of course, be included within a
single system. Instead of sensing the movement of the earth by light
sensitive detection to cause the frame to tilt to follow the sun, the
movement of the frame could be under the control of a clockwork, either
mechanical, electrical or electronic, or could otherwise be programmed to
follow the sun and then return to a starting position. The motor driving
the frame could, for example, be powered by a battery that is charged by a
solar cell.
While it is advantageous for the plastic material to be transparent to the
heat radiating from the sun, it is advantageous to provide reflecting
means on the rearward side of the fluid conducting passages which may be,
for example, an aluminized electroplated surface, or a reflecting foil,
and it is also of advantage to include a pigment or dye in the fluid
passing through the passages in order to enhance the ability of the fluid
to convert the solar energy to heat energy, or to coat the inner walls of
the fluid passages with a pigment or dye or other opaque substance to
convert the solar energy into heat energy and conduct the heat energy into
the fluid.
Advantageously, the unit is mounted on a swivel support so as to be freely
tiltable in all directions and the fluid supply and fluid withdrawal lines
or conduits are connected with the unit through the tiltable support with
the connections including flexible hoses so that the unit is freely
tiltable under all conditions.
The exact nature of the present invention will become more clearly apparent
upon reference to the following detailed specification taken in connection
with the accompanying drawings in which:
FIG. 1 is a somewhat schematic perspective view showing a solar heat
collector according to the present invention.
FIG. 2 is a somewhat schematic plan view looking down on top of a collector
according to the present invention.
FIG. 3 is a transverse section indicated by line III--III on FIG. 1, drawn
at enlarged scale, and partly broken away.
FIG. 4 is a longitudinal section indicated by line IV--IV on FIG. 1, drawn
at enlarged scale, and partly broken away.
FIG. 5 is a fragmentary sectional view drawn at enlarged scale and showing
a modification.
FIG. 6 is a fragmentary sectional view, drawn at enlarged scale, and
showing a modification.
FIG. 7 is a somewhat schematic fragmentary view showing an arrangement for
the swivel mounting of a collector unit according to the present
invention.
FIG. 8 shows a modification.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings somewhat more in detail, the drawings show a
single collector unit, although it will be understood that, as mentioned,
a plurality of units could be connected together for supplying heated
fluid to a single system.
As will be seen in FIGS. 1 and 2, the collector unit, generally indicated
at 10, comprises a body of material, preferably plastic and translucent
and transparent, at least in respect of the heat radiated by the sun. The
body of material may be self-supporting, or it may be mounted in a support
frame 14 which confines the body on the sides thereof and at the bottom
while leaving the upper wall or web 11 thereof exposed. Web 11 thus has
the upper surface 12 disposed for the passage of heat radiation from the
sun therethrough.
The body of the collector is provided with side by side passage means 16 in
about the middle of the height thereof extending in a direction
substantially parallel to the top and bottom walls of the unit. The
passages 16, at the opposite ends thereof, communicate with manifolds 18
and 20 extending transversely to the passages 16 and provide for the
purpose of admitting fluid thereto and withdrawing fluid therefrom.
Passages 18 and 20 communicate with longitudinally extending conduits 22
and 24 on the underneath side of passages 16 and which passages 22 and 24
include connection portions 23 and 25 which extend out the bottom of the
unit through the bottom of frame 14 in a direction substantially
perpendicular to the top and bottom walls of the unit.
As will be seen in FIGS. 3 and 4, the tubular passages 16 are formed in a
central web 28 formed in the body of the collector unit and extending from
side to side thereof. Advantageously, the side to side direction of the
collector unit is the shorter direction and the dimension of the unit in
the direction of the axes of passages 16 is the longer dimension.
As will also be seen in FIGS. 2 and 3, the unit includes longitudinal ribs
26 between web 28 and top wall 11 and longitudinal ribs 34 between the
bottom of web 28 and the bottom wall 13 of the unit. FIG. 2 will also show
that transversely extending stiffening elements 19 could also be supplied
extending at right angles to longitudinal ribs 26 while similar stiffening
elements could be provided beneath transverse web 28 and extending between
ribs 34.
The body of the unit, including top wall 11, bottom wall 13, side walls 15
and web 28, with passages 16, and longitudinal reiforcing ribs 26 and 34,
can be extruded and cut off to any desired length. The longitudinal
passages 22 and 24, which communicate with manifolds 18 and 20, can be
coincidently extruded and thereafter interrupted in the center of the unit
so that the connecting portions 23 and 25 can be connected thereto as by
cementing or fusing.
Similarly, each unit, as will be seen in FIG. 4, has end walls 17, and
these must be supplied to the unit after it has been extruded and cut off.
Further, the transverse manifolds 18 and 20 cannot be extruded together
with the unit so that these elements are mounted in the unit and connected
with the longitudinal passages 22 and 24 and with the opposite ends of the
passages 16 following the extrusion of the unit. After manifolds 18 and 20
are put in place, end walls 17 can be cemented or fused on the ends of the
unit and a complete basic structure is then provided adapted for being
placed in the respective support frame 14.
The longitudinal ribs 26 and 34, together with any lateral reinforcing
elements 19 extending therebetween divide the space inside the unit above
and below web 28 into dead spaces which inhibit loss of heat from the
fluid in passages 16. Thus, if fluid is caused to flow through passages
16, either by convection or by a pump arrangement, while sunlight is
passing through upper web 11, and the heat therefrom being collected by
the fluid in passages 16, relatively efficient conditions will be created
with a minimum loss of heat from each unit by radiation or conduction.
It has been mentioned that the fluid passing through the unit or the inside
surfaces of passages 16 can be dyed or pigmented to increase the
absorption of heat thereby, and it is also possible to provide the
rearward side of web 28 with light reflecting surfaces, as at 21,
especially in respect of modifications to be discussed hereinafter.
As will be seen in FIG. 7, the bottom of frame 14 may be provided in about
the geometric center thereof with a ball element 51 protruding therefrom
which is swivelly receivable in a socket member 53 which is mounted on the
support member 56 on which the collector is mounted. It will be noted that
connectors 23 and 25 extend completely through ball 51 and are connected
by flexible conduits 52 and 54 with main conduits 55 and 57 which lead to
storage or points of distribution of the heated liquid.
Conduit 55 is the one which is connected with supply conduit 22 and supply
manifold 18 and to this end may have a pump 59 therein for pumping liquid
from a place of storage 61 and to which place of storage the heated liquid
is returned via conduit 57.
In the FIG. 5 modification, the unit can be made up of an upper portion 64
and a lower portion 66 which are molded separately and which are then
cemented together in face to face relation so that the semi-circular
grooves 67 therein will make up the longitudinal passages for fluid flow.
The elements 64 and 66 may, in fact, be identical with the manifolds 16
and 18 and conduits 22 and 24 previously referred to being incorporated in
whichever one of the elements 64, 66 is to form the lower part of the unit
after assembly.
It will be apparent that with the arrangement of FIG. 5, the semi-circular
grooves 67 in that part of the unit which is to form the lower half
thereof can be plated or otherwise provided with reflective surfaces as
mentioned above in order to increase the efficiency with which fluid
flowing in the longitudinal channels absorbs heat energy. Such reflective
material can be placed on the inside of the grooves, if so desired.
In FIG. 6, the unit is again made up of molded parts with an uppermost part
69 and a lowermost part 70 which may be identical with each other.
Similarly, the intermediate parts 72 and 74 may be identical with
whichever thereof is to form the lower part being provided with manifolds
and reflective surfaces on the grooves 76 formed therein if so desired. In
the case of each of the modifications of FIGS. 5 and 6, the several parts
are cemented or fused together with end wall portions being added to
complete the assembly and with transverse support members also being
provided extending between the longitudinal support ribs if so desired.
In the FIG. 8 modification is shown a multiply lamination of flat and
embossed sheets processed to form the main body of a solar heat collecting
device and including an outer skin 71 on the top and 72 at the side,
closed cell insulating voids 74 formed beneath skin 71 and between support
ribs 75, and fluid passages, one-half of which are formed as shown at 76
in each of the embossed laminations 78. A pair of the units of FIG. 8 can
be combined as shown in FIGS. 5 and 6 to make up a collector unit.
It has been mentioned that the unit is arranged always to face directly
toward the sun, and for accomplishing this, the upper edges of housing 14
are provided with photosensitive elements 36 on the lateral sides at the
top edge and 37 at the ends on the top edge. The photosensitive elements
are interconnected in a controller 38 which may, for example, include
bridge circuits which detect differences in illumination of the light
sensitive elements of the two pairs thereof.
The signals thus developed by the bridge circuits are supplied via
electrical connectors 40 and 42 to electric motors 44 and 46 which are
connected by elements 48 and 50 to frame 14 at points spaced laterally and
longitudinally, respectively, from the central axis of ball 51 so that the
unit is continuously activated to face squarely toward the sun.
It will be understood that, when a balanced condition is obtained, the
signal supplied to the motor is reduced to zero and movement of the
position of the unit ceases.
As an alternate, a clockwork mechanism can be provided to cause the unit to
approximately follow the sun, or the unit can be conventionally mounted in
the best average rigid orientation in relation to the sun.
Modifications may be made within the scope of the appended claims.
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