U.S. patent application number 12/340379 was filed with the patent office on 2010-06-24 for solar receiver.
This patent application is currently assigned to Skyline Solar, Inc.. Invention is credited to Khiem B. DO, Jason R. WELLS.
Application Number | 20100154788 12/340379 |
Document ID | / |
Family ID | 42264256 |
Filed Date | 2010-06-24 |
United States Patent
Application |
20100154788 |
Kind Code |
A1 |
WELLS; Jason R. ; et
al. |
June 24, 2010 |
SOLAR RECEIVER
Abstract
In one embodiment, a solar receiver has a base plate having a
first surface and a second surface, a plurality of solar cells
positioned over and supported by the first surface of the base
plate, and a multiplicity of fins extending outwardly from the
second surface of the base plate. Each of the multiplicity of fins
has a fin height axis extending generally perpendicular relative to
the base plate, a fin length axis extending generally in parallel
with the base plate, and a bottom end attached to the second
surface of the base plate, wherein each of the multiplicity of fins
are formed from a single, continuous sheet of metal arranged in a
serpentine configuration, and wherein each of the multiplicity of
fins have a plurality of undulations along the length axis of the
fin.
Inventors: |
WELLS; Jason R.; (San
Francisco, CA) ; DO; Khiem B.; (San Jose,
CA) |
Correspondence
Address: |
Beyer Law Group LLP
P.O. BOX 1687
Cupertino
CA
95015-1687
US
|
Assignee: |
Skyline Solar, Inc.
Mountain View
CA
|
Family ID: |
42264256 |
Appl. No.: |
12/340379 |
Filed: |
December 19, 2008 |
Current U.S.
Class: |
126/658 |
Current CPC
Class: |
Y02E 10/52 20130101;
H01L 31/054 20141201; F24S 20/20 20180501; H01L 31/052
20130101 |
Class at
Publication: |
126/658 |
International
Class: |
F24J 2/24 20060101
F24J002/24 |
Claims
1. A solar receiver, comprising: a base plate having a first
surface and a second surface; a plurality of solar cells positioned
over and supported by the first surface of the base plate, each
solar cell having a cell face suitable for receiving solar
radiation that faces away from the base plate; and a multiplicity
of fins extending outwardly from the second surface of the base
plate, each of the multiplicity of fins having a fin height axis
extending generally perpendicular relative to the base plate, a fin
length axis extending generally in parallel with the base plate,
and a bottom end attached to the second surface of the base plate,
wherein each of the multiplicity of fins are formed from a single,
continuous sheet of metal arranged in a serpentine configuration,
and wherein each of the multiplicity of fins have a plurality of
undulations along the length axis of the fin.
2. The solar receiver of claim 1, wherein there are at least four
undulations along the length axis of each fin.
3. The solar receiver of claim 1, wherein the plurality of
undulations have at least four peaks and four valleys along the
length axis of each of the multiplicity of fins.
4. The solar receiver of claim 1, wherein a pitch of each of the
plurality of undulations is no greater than approximately one
undulation per inch.
5. The solar receiver of claim 1, wherein the multiplicity of fins
are made from a metal.
6. The solar receiver of claim 5, wherein the multiplicity of fins
are made from aluminum.
7. The solar receiver of claim 1, wherein the bottom end is
substantially flat whereby substantially all of a surface area of
the bottom end is attached with the second surface of the base
plate.
8. The solar receiver of claim 7, wherein the bottom end is
attached to the second surface of the base plate with an
adhesive.
9. The solar receiver of claim 1, wherein each of the plurality of
fins has a top end opposite the bottom end and wherein a width of
the top end is less than a width of the bottom end.
10. The solar receiver of claim 1, wherein the top end further
comprises an opening to facilitate convective air flow.
11. A solar receiver, comprising: a base plate having a first
surface and a second surface; a plurality of solar cells positioned
over and supported by the first surface of the base plate, each
solar cell having a cell face suitable for receiving solar
radiation that faces away from the base plate; and a multiplicity
of fins extending outwardly from the second surface of the base
plate, each of multiplicity of fins having a bottom end opposite a
top end, the bottom end attached to the second surface of the base
plate, wherein the top end has a width less than a width of the
bottom end, wherein each of the multiplicity of fins are formed
from a single, continuous sheet of metal arranged in a serpentine
configuration, and wherein each of the multiplicity of fins have a
plurality of undulations along a length axis of the fin.
12. The solar receiver of claim 11, wherein the bottom end is
substantially flat whereby substantially all of a surface area of
the bottom end is attached with the second surface of the base
plate.
13. The solar receiver of claim 11, wherein there are at least four
undulations along the length axis of each fin.
14. The solar receiver of claim 11, wherein the plurality of
undulations have at least four peaks and four valleys along the
length axis of each of the multiplicity of fins.
15. The solar receiver of claim 11, wherein the bottom end is
attached to the base plate with an adhesive.
16. The solar receiver of claim 11, wherein the multiplicity of
fins are made from a metal.
17. The solar receiver of claim 11, wherein the top end further
comprises an opening to facilitate convective air flow.
18. Stackable solar receivers, comprising: a first solar receiver,
having: a first base plate having a first surface and a second
surface; a first plurality of solar cells positioned over the first
surface of the first base plate, each solar cell having a cell face
suitable for receiving solar radiation that faces away from the
first base plate; and a first multiplicity of fins extending
outwardly from the second surface of the first base plate, each of
the first multiplicity of fins are formed from a single, continuous
sheet of metal arranged in a serpentine configuration having a
bottom end opposite a top end, the bottom end attached directly to
the second surface of the first base plate, wherein the top end has
a width less than a width of the bottom end; a second solar
receiver, having: a second base plate having a first surface and a
second surface; a second plurality of solar cells positioned over
the first surface of the second base plate, each solar cell having
a cell face suitable for receiving solar radiation that faces away
from the second base plate; and a second multiplicity of fins
extending outwardly from the second surface of the second base
plate, each of the second multiplicity of fins are formed from a
single, continuous sheet of metal arranged in a serpentine
configuration having a bottom end opposite a top end, the bottom
end attached directly to the second surface of the second base
plate, wherein the top end has a width less than a width of the
bottom end, wherein the first multiplicity of fins is interleaved
with the second multiplicity of fins to stack the first solar
receiver with the second solar receiver during transport or
storage.
19. The solar receivers of claim 18, wherein each of the first and
second multiplicity of fins have a plurality of undulations along a
length axis of the fin.
20. The solar receivers of claim 19, wherein an undulating pitch
and an undulating phase of each of the plurality of undulations are
substantially similar.
21. The solar receivers of claim 18, wherein each of the first
multiplicity of fins having a first fin height axis extending
generally perpendicular relative to the first base plate and
wherein each of the second multiplicity of fins having a second fin
height axis extending generally perpendicular relative to the
second base plate.
22. The solar receivers of claim 21, wherein the first multiplicity
of fins extend substantially the entire second fin height of the
second multiplicity of fins when the first multiplicity of fins are
interleaved within the second multiplicity of fins.
Description
FIELD OF THE INVENTION
[0001] The present disclosure relates generally to solar receivers.
More particularly, the present disclosure relates generally to
solar receivers having a heat sink.
BACKGROUND OF THE INVENTION
[0002] The highest cost components of a solar photovoltaic (PV)
system are the solar cells that convert sunlight to electricity by
the photoelectric effect. To use these cells more effectively,
concentrating photovoltaic (CPV) systems focus sunlight from a
larger aperture onto a smaller cell area. The waste heat generated
in the solar receivers used in CPV systems may raise the cell
temperature subjecting the solar cells to thermal stresses causing
malfunction, inefficiencies, and increased costs.
[0003] Heat sinks may be used to absorb and dissipate the heat from
the solar receivers. However, current solar receivers are not
sufficiently efficient from a thermal energy transfer standpoint
while at the same time sufficiently simple, rugged, compact, and
lightweight to be transportable, susceptible to on-site assembly,
or efficiently stored.
Overview
[0004] A solar receiver is described having a base plate having a
first surface and a second surface, a plurality of solar cells
positioned over and supported by the first surface of the base
plate, each solar cell having a cell face suitable for receiving
solar radiation that faces away from the base plate, and a
multiplicity of fins extending outwardly from the second surface of
the base plate. Each of the multiplicity of fins has a fin height
axis extending generally perpendicular relative to the base plate,
a fin length axis extending generally in parallel with the base
plate, and a bottom end attached to the second surface of the base
plate, wherein each of the multiplicity of fins are formed from a
single, continuous sheet of metal arranged in a serpentine
configuration, and wherein each of the multiplicity of fins have a
plurality of undulations along the length axis of the fin.
[0005] In another embodiment, the solar receiver may have a base
plate having a first surface and a second surface, a plurality of
solar cells positioned over and supported by the first surface of
the base plate, each solar cell having a cell face suitable for
receiving solar radiation that faces away from the base plate, and
a multiplicity of fins extending outwardly from the second surface
of the base plate. Each of multiplicity of fins has a bottom end
opposite a top end, the bottom end attached to the first surface of
the base plate, wherein the top end has a width less than a width
of the bottom end, wherein each of the multiplicity of fins are
formed from a single, continuous sheet of metal arranged in a
serpentine configuration, and wherein each of the multiplicity of
fins have a plurality of undulations along a length axis of the
fin.
[0006] Stackable solar receivers are also described with a first
solar receiver having a first base plate having a first surface and
a second surface, a first plurality of solar cells positioned over
the first surface of the first base plate, each solar cell having a
cell face suitable for receiving solar radiation that faces away
from the first base plate, and a first multiplicity of fins
extending outwardly from the second surface of the first base
plate, each of the first multiplicity of fins are formed from a
single, continuous sheet of metal arranged in a serpentine
configuration having a bottom end opposite a top end, the bottom
end attached directly to the second surface of the first base
plate, wherein the top end has a width less than a width of the
bottom end.
[0007] The stackable solar receiver also has a second solar
receiver having a second base plate having a first surface and a
second surface, a second plurality of solar cells positioned over
the first surface of the second base plate, each solar cell having
a cell face suitable for receiving solar radiation that faces away
from the second base plate, and a second multiplicity of fins
extending outwardly from the second surface of the second base
plate, each of the second multiplicity of fins are formed from a
single, continuous sheet of metal arranged in a serpentine
configuration having a bottom end opposite a top end, the bottom
end attached directly to the second surface of the second base
plate, wherein the top end has a width less than a width of the
bottom end, wherein the first multiplicity of fins is interleaved
with the second multiplicity of fins to stack the first solar
receiver with the second solar receiver during transport or
storage.
[0008] These and other features will be presented in more detail in
the following detailed description of the invention and the
associated figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The accompanying drawings, which are incorporated into and
constitute a part of this specification, illustrate one or more
example embodiments and, together with the description of example
embodiments, serve to explain the principles and
implementations.
[0010] In the drawings:
[0011] FIGS. 1A-1D illustrate one embodiment of a heat sink.
[0012] FIGS. 2A-2D illustrates a heat sink fin in accordance with
one embodiment of the invention.
[0013] FIGS. 3A-3C illustrate example solar receivers.
[0014] FIGS. 4A and 4B illustrates an embodiment of a stackable
solar receiver.
[0015] FIGS. 5A and 5B illustrate other embodiments of a stackable
solar receiver.
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0016] Embodiments are described herein in the context of a solar
receiver. The following detailed description is illustrative only
and is not intended to be in any way limiting. Other embodiments
will readily suggest themselves to such skilled persons having the
benefit of this disclosure. Reference will now be made in detail to
implementations as illustrated in the accompanying drawings. The
same reference indicators will be used throughout the drawings and
the following detailed description to refer to the same or like
parts.
[0017] In the interest of clarity, not all of the routine features
of the implementations described herein are shown and described. It
will, of course, be appreciated that in the development of any such
actual implementation, numerous implementation-specific decisions
must be made in order to achieve the developer's specific goals,
such as compliance with application- and business-related
constraints, and that these specific goals will vary from one
implementation to another and from one developer to another.
Moreover, it will be appreciated that such a development effort
might be complex and time-consuming, but would nevertheless be a
routine undertaking of engineering for those of ordinary skill in
the art having the benefit of this disclosure.
[0018] Heat sinks can be used to absorb and dissipate heat from
solar receivers. Heat sinks have a plurality of fins whereby heat
generated by the solar cells dissipates by natural free convection
through the plurality of fins. This minimizes the temperature rise
experienced by the solar cells to improve efficiency and prevent
warping, electrical shorts, or any other malfunctions due to high
temperatures.
[0019] FIGS. 1A-1D illustrate one embodiment of a heat sink. FIG.
1A illustrates a side view of a plurality of heat sink fins and
FIG. 1B illustrates a perspective view of the plurality of heat
sink fins of FIG. 1A. As illustrated in FIGS. 1A and 1B, the
plurality or multiplicity of fins 102 are formed or fabricated from
one continuous roll or sheet of material and bent to form a
serpentine configuration. This eliminates the need to assemble a
heat sink using individual fins and is low cost and easy to
manufacture. The sheet of material can be any material that has
good thermal conductivity such as aluminum, copper, or the
like.
[0020] However, forming the plurality of fins illustrated in FIGS.
1A and 1B has some drawbacks. FIG. 1C illustrates a side view of
various imperfect formations of a bottom end of the plurality of
heat sink fins of FIGS. 1A and 1B. The plurality of fins can be
attached to a base plate 106 of a solar receiver 100 in multiple
bonding areas, such as at the bottom end 104a,b of each of the
plurality of fins 102. Each of the plurality of fins may be
attached to the base plate 106 through any known means, such as
with the use of adhesives.
[0021] Forming a flat and/or squared bottom end 104a, 104b is a
challenging task when forming the serpentine configuration. The end
result may be a rounded bottom end 104a, a skewed bottom end 104b,
or any other non-flat or non-planar configuration.
[0022] The various shapes and configurations of the bottom end
104a, b result in a non-uniform gap 108 between the base plate 106
and each of the plurality of fins 102. Thus, more adhesive is
necessary to bond the fins 102 to the base plate 106, which
increases thermal resistance to the fins 102. Adhesives have less
thermal conductivity than the material used to form the base plate
and/or the plurality of fins. Thus, the amount of adhesive should
be minimized to form a very thin layer of adhesive between the base
plate and the heat sink fin to minimize thermal resistance of the
bonding layer. Although the use of a adhesive has been used to
describe the bond or attachment between the heat sink fin and the
base plate, it is not meant to be limiting as any suitable means
that enables good thermal conductivity contact between the heat
sink fin and the base plate may be used, such as the use of bolts,
screws, mechanical fasteners, soldering, brazing, welding or the
like.
[0023] The thermal conductivity of most adhesives is only
approximately 1% that of aluminum. Thus, a larger gap 108 between
the base plate 106 and the bottom end 104a, b requires more
adhesive to bond the fins 102 to the base plate 106. The use of
more adhesive forms a thicker bonding layer 103, which then impedes
heat transfer from the base plate 106 to the fins 102. Furthermore,
since only a small portion or a small surface area of the bottom
end 104a, 104b of the fin 102 is in close contact with the base
plate 106, the heat flow or transfer from the base plate 106 to the
fin 102 is not symmetric or uniform. More heat flows from the area
where the fin 102 is closer to the base plate 106 than the areas
where the fin 102 is further away from the base plate 106. As such,
there is a higher thermal resistance in the areas where there is
more adhesive, such as the areas where the fin 102 is furthest away
from the base plate 106. This undesirably reduces the effectiveness
of the heat sink and solar receiver 100.
[0024] FIG. 1D illustrates a side view of the plurality of heat
sink fins being attached to the base plate. To bond the plurality
of fins 102 to the base plate 106, the plurality of fins 102 may to
be pressed against the base plate 106 by a force in the direction
illustrated by arrows A. As illustrated in FIG. 1D, the plurality
of fins 102 easily bow when the pressed against the base plate 106.
Although FIG. 1D illustrates a symmetric outwardly bowing of each
of the plurality of fins 102, in practice, uneven bowing occurs
with each of the plurality of fins 102 such that some fins 102 may
bow inward and others bow outward. Additionally, some of the fins
102 may also break or crack as a result of the force or pressure
applied when pressed against the base plate 106.
[0025] As such, there is a limit to the amount of force that may be
applied to the plurality of fins 102. This makes it difficult to
obtain a thin adhesive bonding layer between the base plate 106 and
the plurality of fins 102 to obtain high thermal conductivity
between the base plate 106 and each of the fins 102.
[0026] FIGS. 2A-2D illustrates a heat sink fin in accordance with
one embodiment of the invention. FIG. 2A illustrates a top view of
the heat sink fin and FIG. 2B illustrates a perspective view of the
heat sink fin of FIG. 2A. The heat sink fins 200 are formed or
fabricated from one continuous roll or sheet of material and bent
to form a serpentine configuration similar to the fins illustrated
in FIG. 1A. This eliminates the need to assemble a heat sink using
individual fins and is low cost and easy to manufacture. The sheet
of material can be any material that has good thermal conductivity
such as aluminum, copper, or the like.
[0027] Each fin 202 may also be bent to form a plurality of
undulations 204 along a length axis 206 of each of the fins 202.
The length axis 206 can extend generally in parallel with the base
plate 106. The plurality of undulations 204 creates a wave-like or
ruffled configuration to each of the fins 202. Each fin 202 may
also have a fin height axis 208 that extends generally
perpendicular relative to the base plate. For example, the fin
height and fin height axis may be within 100 of the perpendicular
to the base plate. In another embodiment, the fin height axis 208
need not be generally perpendicular to the base plate. For example,
the fin height axis 208 may vary from a perpendicular axis to the
base plate by about 0.degree.-45.degree..
[0028] In one embodiment, each fin 202 may have between about 2 to
10 undulations along the length axis 206. In another embodiment,
each fin 202 may have between about 3-6 undulations, and in a
specific embodiment, each fin 202 may have between about 4-5
undulations along the length axis 206.
[0029] In another embodiment, each fin 202 has between about 2 to
15 peaks 220 and valleys 222 along the length axis 206 of each of
the fin 202. In another embodiment, each fin 202 may have between
about 3 to 8 peaks 220 and valleys 222 along the length axis 206,
and in a specific embodiment, each fin 202 may have at least 4
peaks 220 and valleys 222 along the length axis 206 of each fin
202.
[0030] Each of the plurality of undulations 204 may have an
undulation pitch 212, which is the distance between each
undulation. In one embodiment, the undulation pitch is no greater
than approximately one undulation per inch. An undulation amplitude
216 is the depth of the undulation parallel to the base plate 106
and an undulation radius 218 is the radius of the curvature
associated with the undulation 204. The heat sink fin 200 may have
a fin pitch 214, which is the distance between similar structures
on an adjacent fin.
[0031] The plurality of undulations 204 forms a heat sink fin 200
having an overall higher stiffness or rigidity that is able to
withstand additional pressure during bonding or attachment to the
base plate without bowing or breaking of the fins 202. The
resulting heat sink fin 200 is more stabilized and able to
withstand bending and distortions.
[0032] FIG. 2C illustrates the bottom ends of the heat sink fin of
FIGS. 2A and 2B and FIG. 2D illustrates the top ends of the heat
sink fin of FIGS. 2A and 2B. The formation of the fins with the
plurality of undulations 204 results in each fin 202 having a
bottom end 206 that is substantially planar or flat which
facilities an efficient bond with the base plate 106. The bottom
ends 206 of each of the fins 202 are substantially perpendicular to
the fin height 208 and parallel to the base plate 106. As
illustrated in FIG. 2D, a top end 226 of each fins 202 may also be
substantially planar or flat and substantially perpendicular to the
fin height 208 and parallel to the base plate 106.
[0033] This results in little to no gap between the base plate 106
and the fin 202, which in turn increases thermal conductivity
between the base plate 106 and the heat sink fins 200. Furthermore,
substantially the entire surface area of the bottom end 206 of each
fin 202 is in close contact with the base plate 106.
[0034] Since the heat sink fin 200 has an overall higher stiffness
or rigidity, it may be bonded or attached to the base plate 106
using a greater force or pressure between the heat sink fin 200 and
the base plate 106. This results in a thinner bonding layer 210.
Additionally, since each of the bottom ends 206 are substantially
planar, the heat sink fin 200 may be bonded to the base plate 106
with a uniform bonding layer 210. Both the thinner and more uniform
bonding layer 210 results in decreased thermal resistance at the
bonding layer 210 between the heat sink fin 200 and the base plate
106.
[0035] The formation of the plurality of undulations along the fin
length axis also allows for the use of thinner material to form the
heat sink fin since the heat sink fin has an overall higher
stiffness or rigidity. This enables the formation of a lighter and
less expensive heat sink and solar receiver. Moreover, it has been
unexpectedly determined that the fin height may be increased
without compromising the mechanical integrity of the heat sink fin.
Thus, the fin height 208 to fin length 206 ratio may increase which
results in high thermal conductivity since there is more surface
area for heat transfer. In one embodiment, the fin height to fin
length ratio may be greater than 0.5.
[0036] FIGS. 3A-3C illustrate example solar receivers. Referring to
FIGS. 3A and 3B, FIG. 3A is a perspective view of the back of one
example solar receiver and FIG. 3B is a perspective view of the
front of the example solar receiver using an embodiment of the heat
sink fin. The solar receiver 300 may have a base plate 106 having a
first surface 304 and a second surface 320 opposite the first
surface 304. The solar receiver 300 may have a plurality of solar
cells 306 positioned over and supported by the first surface 304 of
the base plate 106. Each solar cell 306 has a cell face, facing
away from the base plate 106, which is suitable for receiving solar
radiation.
[0037] The solar receiver 300 has a multiplicity of fins 308
extending outwardly from the second surface 320 of the base plate
106. Each of the multiplicity of fins 308 has a fin height axis 208
and a length axis 206. The fin height axis 208 can extend generally
perpendicular relative to the base plate 106 and the fin length
axis 206 can extend generally parallel with the base plate 106. A
bottom end of each of the fins 308 can be attached to the second
surface of the base plate 106.
[0038] The solar cells 306 and multiplicity of fins 308 may be
attached or assembled to the base plate by any known means such as
those described in co-pending application Ser. No. 12/124,121,
entitled "Photovoltaic Receiver", filed May 20, 2008, which is
incorporated herein by reference in its entirety.
[0039] In use, the solar cells 306 produce waste heat that must be
removed from the solar receiver. The heat may be transferred or
transmitted to the base plate 106, through the bonding layer 210
(FIG. 2C), and to the heat sink fins 308 via conduction. In one
embodiment, the heat can then be dissipated into the surrounding
environment or air via natural convection along the length axis 206
of the multiplicity of fins 308.
[0040] FIG. 3C illustrates a perspective view of another example
solar receiver. A portion of the top end 226 (FIG. 2D) of the heat
sink fins 308 may be removed thereby forming an opening 322 on the
top end of the fin 308. The entire surface of the top end 226 is
not removed to retain the serpentine shape of the heat sink and to
allow the heat sink to be formed from one continuous sheet of
material. This embodiment allows for additional air flow paths in
the region below the top end 226, for example, the area enclosed by
the heat sink fin and the base plate as illustrated by arrow 326.
These additional air flow paths may improve thermal conductance of
the heat, reduce photovoltaic cell temperature, and improve solar
cell efficiency.
EXAMPLE
[0041] Examples are described herein for exemplary purposes only
and not intended to be limiting. An example heat sink fin may be
made from a continuous sheet of material, such as aluminum. The
sheet of material may have a thickness of about 0.020 inches. Each
fin may have a fin length of about 5.50 inches and a fin height of
about 3 inches. Thus, the ratio of fin height to fin length may be
3 inches/5.5 inches=0.55.
[0042] Each fin may have a fin pitch of about 0.25 inches and about
5.5 undulations along the fin length axis. Each fin may have an
undulation amplitude of about 0.050 inches, an undulation period of
about 1 inch, and an undulation radius of about 1.262 inches. The
heat sink may be formed to any desired length. In one embodiment,
the heat sink may have a length of about 52 inches, which results
in the formation of about 208 fins.
[0043] FIGS. 4A and 4B illustrates an embodiment of a stackable
solar receiver. FIG. 4A illustrates a cross-sectional side view of
a solar receiver. The solar receiver 400 may have a plurality of
fins 402 having a bottom end 404 and a top end 406 opposite the
bottom end 404. The bottom end 404 may be attached to the base
plate 106 via a bonding layer 408 as discussed above. Each fin 402
may have a top end width 410 and a bottom end width 412. Current
heat sinks have a top end width 410 that is equal to the bottom end
width 412. This does not allow for the ability of heat sink fins of
two opposing heat sinks to nest or stack within each other for
efficient transport or storage because the spacing between each fin
is equal to the bottom end width. The fins would simply interfere
with each other and not be able to nest or stack within each
other.
[0044] FIG. 4A illustrates a solar receiver 400 having a plurality
of fins 402 with a top end width 410 less than the bottom end width
412 thereby forming fins 402 with a trapezoidal or tapered
cross-section. This allows for the fins of two opposing solar
receivers to nest, stack, or be interleaved within each other as
illustrated in FIG. 4B. FIG. 4B illustrates a perspective view of
the nested, stacked, or interleaved solar receivers. Although the
figure illustrates nested heat sinks, this is not intended to be
limiting as the heat sinks may be attached to the base plate
forming a complete receiver the base plates are not illustrated for
clarity to illustrate how the fins stack or nest within each other.
A first solar receiver 414 having a first multiplicity of fins 418
may be flipped and nested or stacked within a second solar receiver
416 having a second multiplicity of fins 420. The undulation pitch
and undulation phase of each fin, as discussed above, should be
matched and/or substantially similar in order for the solar
receivers 414, 416 to nest within each other.
[0045] The first multiplicity of fins 418 may extend substantially
the entire fin height 208 of the second multiplicity of fins 420
when the first multiplicity of fins 418 are nested within the
second multiplicity of fins 420. The combined height of the first
solar receiver 414 and the second solar receiver 416 is only
slightly greater than the height of one of the solar receivers.
[0046] The ability to nest solar receivers increases the packing
density of the solar receivers during transportation or storage. In
fact, the shipping and storage volume of the solar receivers may be
reduced by a factor of two as compared to current shipping and
storage volumes where nesting of solar receivers are not possible.
As such, concomitant shipping and storage costs may be reduced
which can influence the commercial viability of CPV systems.
[0047] Furthermore, nesting the solar receivers reduces the
probability of fin damage during transportation or storage. The
fins form a mechanical protection layer for each opposing fin
thereby increasing the mechanical robustness of the structure.
[0048] FIGS. 5A and 5B illustrate other embodiments of a stackable
solar receiver. FIGS. 5A and 5B illustrate side views of
alternative embodiments of a stackable solar receiver. Referring to
FIG. 5A, the solar receiver 500 has a plurality of tapered heat
sink fins 510. Each fin 510 has a top end width 504 that is less
than a bottom end width 506. The tapered angle 508 of each fin 510
may be between about 2.degree. to about 30.degree..
[0049] FIG. 5B illustrates another embodiment of a stackable solar
receiver. The solar receiver 502 may have a plurality of heat sink
fins 512. Each fin 512 may have a rounded taper at the top end 514
such that the bottom end width 516 is greater than a width of the
tapered top end 514. The difference in width between the bottom end
518 and the top end 514 of the fins 512 allows two solar receivers
to nest within each other for transport or storage.
[0050] Although FIGS. 5A and 5B are illustrated with the top end
width less than the bottom end width, this is not limiting as the
opposite may be possible. The top end width may be greater than the
bottom end width. In this embodiment, one heat sink may slideably
engage another heat sink in order to nest or stack the heat sink
fins.
[0051] While embodiments and applications of this invention have
been shown and described, it would be apparent to those skilled in
the art having the benefit of this disclosure that many more
modifications than mentioned above are possible without departing
from the inventive concepts herein.
* * * * *