Note: Descriptions are shown in the official language in which they were submitted.
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THERMAL ELECTRONIC SOLAR COLLECTOR
The present invention relates to the art of methods and apparatus for
converting solar
energy to thermal and electrical energy through a thermoelectric fluid
containing micro-
structures for absorbing radiated heat and converting photonic energy into
electronic
energy. The present invention also relates to the use of solar collector
apparatus for
conversion of sunlight radiated energy to a thermoelectric fluid and mechanism
for
pumping and transporting the stored energy to a heat exchanger and electrode
system.
BACKGROUND OF THE INVENTION
Devices for solar energy collection and conversion can be classified into
concentrating
types and non-concentrating types. Non-concentrating types of solar collectors
capture
heat from sunlight with a flat array composed of absorbing materials or
devices such as
photovoltaic cells or fluid conduit, for example. The output is a direct
function of the area
of the array. Concentrating type of solar collectors focuses the energy rays
using a
parabolic reflector or a lens system, multiplying the sunlight intensity
several times onto
a focal point. The sunlight is concentrated to increase the intensity of
conversion of solar
radiation to higher photovoltaic outputs or to higher temperature of collected
heat from
the solar radiation to provide for higher temperature applications.
In conventional concentrating and non-concentrating solar energy collectors,
the solar
radiation is typically absorbed through a metallic conductive conduit or
photovoltaic cell
array. The solar radiation can be focused at a point from a circular reflector
(e.g., a dish-
shaped reflector) or along a focal line from a cylindrical shaped reflector.
Such apparatus
perform efficiently in ideal conditions and climates where a lower energy
output less than
700 Wth/M2 heat and 150 Wev/M2 are sufficient throughput.
However, even conventional concentrating solar energy receivers require
improvement
for two reasons. First, the solar radiated energy conversion in conventional
systems
occurs at the surface of an absorbing material which conducts thermal energy
to a conduit
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which in turn conducts the thermal energy to a fluid being pumped through the
conduit,
creating numerous thermal resistances. Secondly, a large portion of the solar
radiated
energy absorbed initially by the absorbing material is reflected back to the
atmosphere
during its conductivity path to the conduit.
4146408 Mar., 1979 Nelson 136/259.
4153474 May., 1979 Rex 136/246.
4388481 Jun., 1983 Uroshevich 136/246.
4943325 Jul., 1990 Levy 136/259.
6020553 Feb., 2000 Yogev 136/246.
6225551 May., 2001 Lewandowski et al. 136/246.
5551991 Sep., 1996 Avero 136/248.
6018123 Jan., 2000 Takada.
Steadily, the sun delivers energy at the earth's surface at the average rate
of 1,000
Watts/Mz per hour. This is enough energy to heat and light the whole world on
a
continuous basis. However, the efficiency of conventional solar collectors in
converting
radiated solar energy into heat and electricity has been limited. The flat
plate solar
collectors widely used at the present time provide applications no better than
heating
dwelling spaces and hot water for domestic uses. The present day technology
for
collecting solar energy at a significantly elevated temperature is limited to
parabolic
reflectors and focusing lenses, which are expensive, complex and cumbersome
technologies and are neither promising nor encouraging in terms of their
present status
and their future potential. One of the most typical examples of solar energy
application is
the use solar energy for air conditioning in the tropical and subtropical
regions where the
expense of cooling in summer time is far greater than the expense of heating
in winter
time. Another prosperous application is the generation of steam for power
stations.
Solar photovoltaic cells are usually produced as small units, each capable of
producing
limited electric power in the range of a few watts. For large scale
applications, it is
necessary to integrate many cells to form a module that can produce higher
electric
power. Due to mechanical limitations, very close packing of cells is very
difficult and in
many cases, each cell has a small area with inactive material. When such a
module is
formed, a portion of the area of the module is inactive and when oriented
towards the sun,
a fraction of the light that is incident on this area is not utilized.
Moreover, when the
module is used for converting concentrated solar radiation to electricity,
this fraction of
concentrated radiation can damage the module.
There is a need to improve and develop new systems that convert solar energy
to both
thermal and electrical energy efficiently in severe and extreme climates to
deliver heat
and electric power reliably with minimal losses.
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SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a solar collector
that absorbs
radiated solar energy to produce thermal energy at higher efficiency.
Another object of the present invention is to provide a solar collector that
absorbs
radiated solar energy by means of a thermoelectric fluid composed of micro-
structures
converting photonic energy into electronic energy.
A further object of the present invention is to provide a solar collector that
absorbs
radiated solar energy to produce thermal and electrical energy for
residential, industrial
and commercial needs and into systems that are affordable.
Yet another object of the present invention is to provide a highly efficient
solar collector
employing translucent conduits allowing solar radiated energy to be captured
directly by
the thermoelectric fluid and eliminate numerous thermal resistances and
conductivity
bridges.
These and other objects of the present invention will become clear as the
description
thereof proceeds.
There is disclosed herein a solar energy collector comprising an array of
translucent
passages connected at one end to a fluid inlet header and at the other end, to
a fluid outlet
header and placed in a direct path with sunlight. A opaque thermoelectric
fluid composed
of homogenous propylene glycol and micro structure semiconductors is processed
through the array of translucent passages. Solar energy radiates onto the
array of
translucent passages allowing the thermoelectric fluid to absorb solar energy
directly and
causing the thermoelectric fluid to increase in temperature. Fraction of the
solar energy
absorbed by the thermoelectric fluid is converted from heat and photonic
energy to
electron energy within the micro structure semiconductors.
The solar radiated thermoelectric fluid circulates by pumping mechanism from
the inlet
header to the outlet header of the translucent passages and to an energy
storage tank
through a conversion system composed of a heat exchanger and a planar
electrode system
where thermal and electrical energies are recuperated. The thermal energy and
electrical
energy thus recuperated in the conversion module can be used for heat and
power
applications.
The energy conversion module includes a reception surface composed of planar
electrodes and heat exchanger. The planar electrodes act as poles where
electrons are
collected as voltage. The heat exchanger collects the thermal energy from the
fluid
through conduction.
The thermoelectric fluid may include up to 30% micro-structure semiconductors
in
weight of the total component of the fluid solutions which is equivalent to 3
times the
surface area of the solar collector if the micro-structure semiconductors were
laid down
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next to each other. Solar absorptivity of the thermoelectric fluid is directly
proportional to
the content and absorptivity of the micro-structure semiconductors in the
solution.
However, other mechanical and fluid thermodynamics consideration limits the
total
content of micro-structure semiconductor into the fluid. Nonetheless, the
efficiency of the
solar collector is enhanced sharply by use of the opaque thermoelectric fluid.
In an alternate embodiment, there is disclosed a concentrating solar energy
collector
comprising multiple parabolic reflectors having high reflectivity surface on a
concave
side of the reflector and having a focal axis extending from a concave side of
the reflector
which passes through a focal point where a translucent glass tube is placed. A
opaque
thermoelectric fluid passes through the translucent glass tube and is
irradiated by the
solar light converging at the focal point. This alternate embodiment allows
higher
temperatures being reached due to convergence of solar light equivalent to 100
to 1000
suns depending on the geometry and size of the parabolic surface with respect
to the glass
tube surface.
It is therefore first a broad object of the present invention to ameliorate
the disadvantages
of the prior art solar collectors.
It is a further broad object of the present invention to provide a solar
collector system
capable of absorbing radiated solar energy for conversion to thermal energy
and
electronic energy to supply heat and electricity for a wide range of
applications.
It is still a further object of the present invention to provide a solar
collector system that
eliminates the use pipes and other metallic passages between the absorbing
fluid and the
radiated sun energy.
In accordance with the present invention, there is therefore provided a high
efficiency
solar radiation collector, thermal and electronic conversion system,
comprising at least
one absorbing surface and thermoelectric fluid, said surface being made of a
translucent
material and said thermoelectric fluid being made of thermal absorbing micro-
structure
semiconductors, wherein said thermoelectric fluid absorbs solar energy and
wherein said
conversion system recuperates thermal energy and converts fraction of thermal
energy to
electric energy.
The present invention was accomplished on the basis of the above-discussed
recognition.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages
thereof,
reference is now made to the following description taken in conjunction with
the
accompanying Drawings in which:
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FIG. 1 illustrates a typical solar energy system application comprising a
solar collector,
thermal fluid conduits, thermal reservoir and thermal exchanger.
FIG. 2 illustrates an array of translucent passages comprising a inlet for the
pumped
thermal fluid entrance and outlet for the thermal fluid exit.
FIG. 3 illustrates the thermoelectric fluid micro-structures and a
representation of the
thermal absorption, conductivity, convection and thermal radiation.
FIG. 4 illustrates the thermoelectric fluid micro-structures and a
representation of the
photonic absorption, reaction and representation of the electron transport.
FIG. 5 is a pictorial drawing illustrating the conversion system comprising a
thermal
exchange section and a electron exchange system.
FIG. 6 illustrates another alternate embodiment of a concentrating solar
energy collector
wherein a collector tube is installed at the focal area.
While the principles of the present invention have now been made clear by the
illustrative
embodiments, it will be immediately obvious to those skilled in the art that
many
modifications of the structure, arrangements, elements, proportions and
materials which
are particularly adapted to a certain working environment and operating
condition in the
practice of the invention are possible without departing from those principles
of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is illustrated a typical solar energy system
according to the
present invention. The solar collector 2 is installed on a typical building
roof 1 and
secured. The pipe 3 brings the thermoelectric fluid 12 through the solar
collector 2 by
pumping mechanism. The thermoelectric fluid absorbs the solar radiated energy
13
incident onto the surface of the solar collector 2. The therefore heated
thermoelectric
fluid 12 is returned by means of insulated pipe 4 through conversion system 6
to the
thermal exchanger 5. The energy contained in the thermoelectric fluid 12 is
recuperated
as heat and electric energy through the conversion system 6. The electric
energy is stored
in batteries 14 and heat is stored in reservoir 8 where heat is reabsorbed by
thermal coil 7
and ejected in heating devices 11 to supply ambient comfort heat to the
building I.
Sanitary water can also be extracted from reservoir 8 and brought to reservoir
9 through
insulated pipe 10 for supplying clean warm water.
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Referring now to FIG. 2, there is illustrated one embodiment of a solar energy
collector
20 according to the present disclosure, comprising an array of translucent
passages 21.
The solar energy collector 20 includes a inlet pipe 22 and outlet pipe 23 to
allow the
thermoelectric fluid 12 of figure 1, to flow in and out with pumping action.
There is
provided onto the inlet pipe 22 and outlet pipe 23, a threaded section 24 an
25 to allow
for pipe connections. The array of translucent passages 21 comprises a
multitude of
channels 27 enhancing laminar flow through the solar collector 20 and
increasing solar
radiation absorption through surface 26 by the thermoelectric fluid 12.
While referring now to FIG. 3, there is illustrated an enlarged view of the
micro-structure
semiconductors 32 within the thermoelectric fluid 12 and a single channel 30,
part of the
multitude of channel 27, illustrating the photon absorption process. The
photons
contained into light rays 31 are absorbed by micro-structure semiconductor 32.
The
photons transfer energy to electron 38 to flow freely to find electron holes
in the micro-
structure. This process creates electric current. The radiated light rays 31
induce heat into
the micro-structure 32 which is partly absorbed, partly radiated to nearby
elements of the
micro-structure 34, partly convected to the fluid 33 and also partly radiated
to the fluid 35
and the atmosphere 36. The size x 37 of the micro-structure elements vary from
500
nanometer to 5 micrometers and are composed of multiple elements.
Referring now to FIG. 4, there is illustrated the thermoelectric fluid 41 and
micro-
structure semiconductors 40. The solar radiated light energy 42 induce photons
and
photocurrent transients through the electronic process occurring into the
micro-structure
semiconductors 43. The electron transport to the conversion system electrodes
is
achieved through the thermoelectric fluid 41 acting as an electrolyte. The
shape and the
time domain for the current transients are dependent on the conversion system
of figure 5
membrane thickness, membrane material and thermoelectric fluid conductivity.
The
micro-structure semiconductors 45 travel in suspension within the
thermoelectric fluid 41
due to the density of the fluid which is mainly composed of propylene glycol,
chemically
made micro-structure semiconductors 45, 43 and electrolyte. The micro-
structure
semiconductors 45 have a higher thermal absorptivity than the thermoelectric
fluid 41
and exchange heat energy 46, 47 on their way to the conversion system.
Referring now to FIG. 5, there is illustrated the conversion system 50,
comprising a
thermal exchanger 53 with inlet 51 and outlet 55 for the proper flow of the
thermoelectric
fluid. A water thermal absorbing section comprising an inlet 52 and outlet 54
allow
sanitary water from reservoir 6 to be heated. Electronic energy carried by the
micro-
structure semiconductors 56 is absorbed through the membrane 58 and thin film
electrode
57.
Referring now to FIG. 6, there is illustrated in cross section, a alternate
solar multiple
parabolic collector embodiment 60 comprising multiple parabolic reflectors 61
shown in
cross section. As is well known, this is an efficient shape for receiving
incident solar
energy radiation. However, the concentrating solar energy receiver 60 of the
present
disclosure is not limited to any parabolic shape reflector 61 but could be
other geometric
shapes such as an ellipse, an oval, a rectangle (i.e., a cylindrical
reflector), a polygon or
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an array of regular polygons or any other closed plane figure. Such an array
of panel
segments could be a composite of contiguous shapes placed edge-to edge or a
composite
of reflecting elements arranged in proximity to one another or a composite of
reflecting
elements arranged in predetermined positions though not necessarily close
together.
While continuing reference to FIG. 6, Further, the solar multiple parabolic
collector
comprises a plurality of glass translucent tubes 62 allowing the
thermoelectric fluid to
flow by pumping mechanism. The solar multiple parabolic collector 60 also
comprises
insulation 63, seal 65 and glazed plate 64 to enhance its performance.
