U.S. patent application number 11/948029 was filed with the patent office on 2009-06-04 for solar line boiler roof.
Invention is credited to Daniel D. De Lima.
Application Number | 20090139512 11/948029 |
Document ID | / |
Family ID | 40674486 |
Filed Date | 2009-06-04 |
United States Patent
Application |
20090139512 |
Kind Code |
A1 |
Lima; Daniel D. De |
June 4, 2009 |
Solar Line Boiler Roof
Abstract
A solar energy devices comprises a plurality of half cylinder
troughs along a slanted roof of a static structure. The sun light
entering the trough is reflected onto a secondary collector
situated at a focus line of the primary collector. Light is
directed onto a boiler tube contain a fluid to be used in an
appropriate thermal cycle. Solar panels may be provided on surfaces
along the secondary collector to power portions of the system.
Braces can be provided to support the secondary collector over the
primary collector. Reflectors may be provided to redirect light
away from the braces onto the primary collector
Inventors: |
Lima; Daniel D. De;
(Norfolk, VA) |
Correspondence
Address: |
MEREK, BLACKMON & VOORHEES, LLC
673 S. WASHINGTON ST.
ALEXANDRIA
VA
22314
US
|
Family ID: |
40674486 |
Appl. No.: |
11/948029 |
Filed: |
November 30, 2007 |
Current U.S.
Class: |
126/600 ;
126/623; 126/646 |
Current CPC
Class: |
Y02E 10/40 20130101;
F01K 25/10 20130101; F24S 30/425 20180501; Y02E 10/44 20130101;
F24S 23/80 20180501; F24S 50/20 20180501; F24S 23/74 20180501; F24S
20/67 20180501; F22B 1/006 20130101; F24S 23/79 20180501; Y02B
10/20 20130101; F24S 20/20 20180501; Y02E 10/47 20130101 |
Class at
Publication: |
126/600 ;
126/646; 126/623 |
International
Class: |
F24J 2/38 20060101
F24J002/38; F24J 2/04 20060101 F24J002/04; F24J 2/46 20060101
F24J002/46 |
Claims
1. A solar energy line boiler comprising: a trough having a
substantially circular section and a light reflective interior
surface; a boiler tube provided at a center of curvature of said
trough; a reflector of constant interior reflecting cross-section
for transposing light from a focus of said trough to the center of
curvature where said boiler tube is provided, said reflector
rotatably mounted to accommodate variations in the focus of said
trough; and a pump for driving fluid through said boiler tube;
wherein said trough is aligned such that an axis of rotation of
said reflector is east to west such that fluid running within said
boiler tube absorbs and transforms direct solar energy to an energy
source for a static structure.
2. The solar energy line boiler according to claim 1, including: at
least two troughs, each trough having a boiler tube and a
reflector.
3. The solar energy line boiler according to claim 1, including
multiple parallel boiler tubes, where a principle boiler tube is
positioned at the center of curvature of said trough, and at least
one secondary boiler tube is proximally positioned parallel
thereto.
4. The solar energy line boiler according to claim 1, including a
reflector motion and control photovoltaic system comprising: a
photovoltaic panel mounted above said reflector; and a pair of
photovoltaic sensor strips powered by the photovoltaic panel
mounted to sides of said reflector; whereby the reflector may be
positioned by comparing and balancing outputs of the photovoltaic
sensor strips.
5. The solar energy line boiler according to claim 4, wherein the
outputs of the sensor strips is further used to control said pump
for driving fluid through the boiler tube.
6. The solar energy line boiler according to claim 5 wherein the
pump provides a fluid pumping rate directly proportional to energy
received by the photovoltaic system.
7. The solar energy line boiler according to claim 1 wherein the
boiler tube is provided in a convection insulated light transparent
housing.
8. The solar energy line boiler according to claim 1 including
lateral braces that transverse the trough, boiler tube support for
mounting the boiler tube to the braces, and notches provided in the
reflector for the tube support.
9. The solar energy line boiler according to claim 8 including
bearings for rotating the reflector, the reflector having planar
reflective surfaces at each of the notches; tube unions for
dismantling and servicing the boiler tube provided in the notches;
and an eccentric fluid bypass provided between tube unions within
each of the notches.
10. The solar energy line boiler according to claim 1, wherein the
troughs form a roofing section for a static structure.
11. The solar energy line boiler according to claim 10, where said
troughs are inclined along an east west axis, at an angle of
inclination for the latitude of said static structure.
12. A static structure including a solar energy line boiler as part
of its roof, the solar energy line boiler comprising: a trough
having a substantially circular section and a light reflective
interior surface; a boiler tube provided at a center of curvature
of said trough; a reflector of constant interior reflecting
cross-section for transposing light from a focus of said trough to
the center of curvature where said boiler tube is provided, said
reflector rotatably mounted to accommodate variations in the focus
of said trough; and a pump for driving fluid through said boiler
tube; wherein said trough is aligned such that an axis of rotation
of said reflector is east to west such that fluid running within
said boiler tube absorbs and transforms direct solar energy to an
energy source for the static structure.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method and apparatus for
collecting solar power and a building or other static structure
incorporating the same.
[0003] 2. Description of the Prior Art
[0004] Interest in solar power continues to accelerate in the face
of global warming, concern over the long term availability of
petroleum and the pressures of rising energy prices. Tapping even a
portion of available solar power has the potential to reduce
reliance on petroleum and to hopefully reduce pressures on the
national energy grid by distributing power generating sources more
locally. Even cutting external energy demands by three percent
would have a significant impact on energy demand and therefore on
energy prices. And recently some cities have joined the effort by
loaning the money to buy solar equipment to residents to encourage
residents to buy solar.
[0005] One drawback to solar power, however, is that it tends to
have low thermal efficiencies and the amount of area that a home
would need to break even for the year on energy requirements is
very high. What is needed is a way to make the most of the solar
energy available to power a home while minimizing the costs of the
power system to make solar power more energy efficient, more
attractive and financially more effective.
[0006] None of the above inventions and patents, taken either
singly or in combination, is seen to describe the instant invention
as claimed.
SUMMARY OF THE INVENTION
[0007] According to a preferred embodiment of the present
invention, two half cylinder troughs along a slanted roof of a
building. The sun light entering the trough is reflected onto a
secondary collector situated at a focus line of the primary
collector. Light is directed onto a boiler tube contain a fluid to
be used in an appropriate thermal cycle. Solar panels may be
provided on surfaces along the secondary collector to power
portions of the system. Braces can be provided to support the
secondary collector over the primary collector. Reflectors may be
provided to redirect light away from the braces onto the primary
collector.
[0008] Accordingly, it is a principal object of a preferred
embodiment of the invention to provide a highly efficient and cost
effective solar system. It is another object of the invention to .
. . .
[0009] It is a further object of the invention to . . . .
[0010] Still another object of the invention is to . . . .
[0011] It is an object of the invention to provide improved
elements and arrangements thereof in an apparatus for the purposes
described which is inexpensive, dependable and fully effective in
accomplishing its intended purposes.
[0012] These and other objects of the present invention will be
readily apparent upon review of the following detailed description
of the invention and the accompanying drawings. These objects of
the present invention are not exhaustive and are not to be
construed as limiting the scope of the claimed invention. Further,
it must be understood that no one embodiment of the present
invention need include all of the aforementioned objects of the
present invention. Rather, a given embodiment may include one or
none of the aforementioned objects. Accordingly, these objects are
not to be used to limit the scope of the claims of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an environmental perspective of a static structure
employing an embodiment of the present invention.
[0014] FIG. 2 is a perspective view of primary and secondary
collectors of the present invention.
[0015] FIG. 3 is a diagrammatic view showing reflection of light in
the primary collector.
[0016] FIG. 4 is a cross section of a secondary collector according
to the invention.
[0017] FIG. 4b is an end plan view of the primary and secondary
collector according to a second embodiment of the invention.
[0018] FIG. 5 is a perspective view of the secondary collector and
braces according to a further embodiment of the invention.
[0019] Similar reference characters denote corresponding features
consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0020] The present invention is to an improved method and apparatus
for collecting and utilizing solar power, and a building
incorporating the same. As shown in FIG. 1, a building 110
incorporating at least one solar trough 120 is shown. A portion of
the building includes a downward slanting wall incorporating two
side by side troughs 120. This wall preferably faces in the most
efficient solar collecting direction to maximize the amount of
sunlight hitting the face of the wall on an annual basis or using
other algorithms to maximize, for example, the caloric impact of
the sun ("solar incidental energy") on the wall on a set periodic
basis. Generally, the wall will face an Eastern direction so that
as the sun rises, the sun will generally follow the longitudinal
axis of the troughs 120. It should be noted that as the earth tilts
through its orbit, the sun will track through 23 degrees north or
23 degrees south of the axis of the earth. The sun will thus
substantially track parallel to the troughs as the earth tilts
through its annual tilt cycle. As will be explained further
hereunder, the vertical walls of the trough and optionally tilting
of the collectors will act to maximize solar collection as the
earth tilts through its cycle. The troughs could be extended to
slope in a Westward direction as well to capture the afternoon sun,
however, for simplicity, the invention will be described with
regard to one trough, with the understanding that any number of
troughs and trough orientations could be used. Preferably the
troughs are built into the structure of the building, but one
skilled in the art would recognize that the troughs could be added
to the building later or independently affixed to the building.
Preferably the troughs are incorporated into the structure of the
building to increase the stability of the troughs, to prevent
vulnerability to weather such as low pressure storm cells, and to
increase the stability of the building to accept additional
equipment such as air conditioning units that may be incorporated
into the roof and solar system.
[0021] The trough itself ("primary collector") 120 is preferably
semicircular in profile, basically a hollow cylinder cut
substantially in half. The trough faces upward to allow sunlight in
to shine off each face and focus onto a central focus line (F-F,
FIG. 2) that will be discussed further herein. The trough is
preferably permanently tilted to maximize exposure to the sun.
Depending on various requirements and applications, the degree of
tilt may be varied, but preferably the degree of tilt is a function
of the latitude of the building incorporating the solar receptor.
Ideally, the degree of tilt is the same as the latitude, such that
a building 20 degrees north latitude will have an angle as if the
cylinder were sectioned 20 degrees relative to the earth's surface.
This angular tilt (as opposed to the axial tilt of the centerline
of the cylinders along the building wall or roof) causes the
opening "face" (the plane along which a hypothetical cylinder would
be cut to form the semicircular cross section) to point towards the
mean path of the sun across the trough. In this way, the trough
will have the greatest average sun light on the trough throughout
the year. To further aid in collecting the maximum amount of
sunlight, the semicircular cross section of the trough may not
include the full 180 degree cross section. While in theory, rays at
the extreme edges of the semicircle will still reflect and focus on
the central foci, it has been found that removing a portion of the
edge to reduce the shading effect of the outer walls provides
greater overall solar energy capture than providing the full
semicircular walls. Therefore, it is preferred to trim the trough
walls to about 178 degrees, to maximize solar energy
collection.
[0022] Optionally, as shown in FIG. 1, the trough may extend on
more than one slanted wall to take advantage of morning and
afternoon soon. The trough is divided perpendicular to the axis
into two sections, with one section mounted on each opposing,
slanted building wall in an inverted V shape. One wall is shown as
the front side of the building 110, and the other wall is the back
side of the A shaped building. In this way, the walls are
preferably formed by cutting the trough in half perpendicular to
its axial centerline to provide two like semicircular troughs. The
first trough is mounted 20-40 degrees (i.e., axial center line to
earth surface angle) towards the east and the second is mounted
20-40 degrees towards the west in an inverted V pattern. In this
way one trough efficiently collects morning sun and the other
trough efficiently collects afternoon sun. By distributing the
collection of sunlight more regularly throughout the day, there are
fewer (or smaller) peaks in the energy collected, allowing smaller
boilers and other equipment downstream to be used.
[0023] One advantage of the trough configuration compared to flat
solar panels is that the troughs are somewhat self cleaning. Water
from rain storms or from induced spray run through the troughs
under force of gravity to clean the troughs of any debris. The
troughs may optionally have a water source associated at an upper
end or along the troughs to allow the troughs to be cleaned
periodically.
[0024] As shown in FIG. 2, running parallel to the axis of the
primary collector ("trough") 120 is a secondary collector 140. The
secondary collector is located within the trough and surrounds the
foci of the reflections within the trough. Unlike a normal solar
panel, the trough is not made of panels that absorb the sun, but
are instead made of panels that reflect the sun onto a second
collector and from the secondary collector onto a boiler tube.
Because the trough is nearly a complete half cylidnder (i.e.,
semicircular in cross section) and light from the sun enters the
primary collector in substantially parallel rays, the sun light
that is received within the primary collector will focus the light
on or more accurately through a single point F (FIG. 3). One
skilled in the art will recognize that since the trough is three
dimensional and not just a two dimensional semicircle, that point F
is actually a line F-F that parallels the axis of the trough, and
that the focus line changes according to the direction from which
light enters, but all light parallel to line E (including lines A,
B and D) will reflect through the same focal line F-F.
[0025] As mentioned above, the primary collector 140 acts to focus
all of the light going through point F ("line F-F") through the
opening of a secondary collector, which then focuses the light onto
boiler tube 150. The boiler tube contains water or preferably a
more suitable refrigerant which is designed or chosen for the
particular thermal cycle which the fluid undergoes, but for
purposes of clarity and simplicity, the fluid of the system will be
referred to in this application as water.
[0026] FIG. 4 shows a cross sectional view of the secondary
collector. Each wall of the secondary collector is preferably
described by an ellipse to maximize reflection through the
secondary collector directly onto the boiler tube 150. Each wall's
elliptical vertical centerline is separated by a distance X.
Overlapping portions described by the two ellipses is removed to
form a heart shaped secondary collector. A bottom portion described
by the ellipses is also removed to form a mouth 142 to allow the
sun light to enter the secondary collector. The secondary collector
preferably overlaps the focus point of the primary collector. More
preferably, the mouth 142 of the secondary collector is aligned
such that the focus point F is located in the middle of the lips
("lower most edge") 144 of the mouth of the secondary collector. As
shown by the lines B-E, the angular arrangement of the interior
reflecting surface 146 of the secondary collector 140 act to
reflect all received light onto the boiler tube 150. Additionally,
the interior surfaces of the secondary collector may be enhanced to
increase the reflectivity of the surfaces, especially by polishing
or silvering. The boiler tube may have one central chamber as shown
in FIG. 5, or may be divided into multiple chambers to heat various
fluids. FIG. 4 shows a preferred embodiment having three separate
chambers for heating three distinct fluids. The fluids in the
various chambers may be the same type of fluid, but are capable of
being run in separate, divided circuits, that is without
mixing.
[0027] In a most preferred embodiment, solar cells are the side or
sides of wing 148 near the mouth 142 of the secondary collector to
catch stray solar rays. Light may reflect off the primary collector
at a less than ideal angle due to surface imperfections, blockage
caused by debris or for other reasons. Slight wings may be added to
the lower end of the secondary collector near the mouth. Preferably
the width of the wings does not substantially change the outer
profile (i.e., does not cast additional shadow) of the secondary
collector. The mouth 142 of the secondary collector is designed to
be substantially larger than the focal point F to catch stray
light. Light that is reflected just beyond the mouth that would
normally be reflected out of the primary reflector back to the sky
can be captured by these wings 148. Solar panels on the bottom and
optionally on the top of the wing, catch sun light directed onto
the wing. This additional energy may be utilized as needed, but is
preferably used to power the functions of the solar collector
itself, such as to rotate and/or align the secondary collector as
will be discussed further below.
[0028] The top of secondary collector will generally point towards
the sun. This will cause a shadow on the primary collector at a
point below the mouth. The solar energy that would normally be
wasted can be captured in part by providing solar panels 152 at the
top of the secondary collector. Preferably, the total width (x') of
the top solar panels 152 is the same or nearly the same as the
width (x'') of the body of the secondary collector to maximize the
width of the solar panel without increasing the profile ("shadow")
of the secondary collector. Likewise, the wings 148 at the mouth of
the collector are configured to have the same width as the
secondary collector for the same reasons. It should be noted that
the energy collected by the solar panel 152 will be directly
related to the energy collected at the boiler tube 150, since the
solar panels receive a fraction of the light that is also normally
directed onto the boiler tube. This may be used in part to measure
the light collected on or energy imparted to the boiler tube or for
other purposes.
[0029] The secondary collector 140 is held in place over the
primary collector 120 by a number of braces 160. While the primary
and secondary collectors are preferably continuous along the length
of the trough and have a substantially constant cross-section along
the length, the braces 160 are only spaced intermittently along the
trough. This is desirable to limit the shading effect of the braces
on the primary collector. Any shade caused by the braces, which
overly the primary collector, would reduce the amount of solar
energy collected by the primary collector and thus needs to be
minimized. The total number and size of the braces would depend on
the weight and forces on the secondary collector, including forces
from wind, rain, and snow.
[0030] These lateral braces 160 support the boiler tube and
secondary collector preferably at both ends and in a series of
spaced apart braces along the secondary collector. These braces
preferably are insulated with a low conductivity material such as
ceramics, especially where the braces connect to the boiler tube to
minimize any heat losses from the boiler tube. As shown in FIG. 5,
the brace may include a tube that connects to the boiler tube 160
by an insulated spacer block 161 In order to lessen the shading
effect of the braces, each brace may have a reflector 162 mounted
thereto to deflect the sun onto the primary collector. The brace
reflector preferably includes an inverted V shaped reflector
sloping away from the brace on either side of the reflector to
maximize the amount of light deflected away from the brace. In this
way the individual sloped plates of the bracket reflectors reflect
away from the boiler tube as well and on to the primary collector.
Insulators around the boiler tube can be discontinued where the
braces are to minimize the shading on the primary reflector. The
braces are preferably attached to the secondary reflector and
boiler tube to allow the secondary reflector rotate for the reasons
discussed below. The boiler tube and the secondary reflector may
rotate together, but preferably the boiler tube is fixedly
connected to the braces and the free floating secondary collector
is connected to rotate about the cylindrical boiler tube. A cutout
163 may be provided on the secondary collector to allow the
collector to rotate about the brace without interfering with the
braces.
[0031] The secondary collector is preferably assembled as one
continuous piece as shown in FIG. 5, but may also be divided into
continuous sections between the braces. The sections of the
secondary collector may be joined together to rotate as one unit or
may be separate pieces that are rotated in coordination with each
other, depending on the amount of rotation desired and the location
of the location and number of braces as the braces will tend to
limit the amount of rotation that joined sections of secondary
collectors can rotate about the boiler tube without interfering
with the braces.
[0032] Any method can be used to rotate the secondary collector
about the boiler tube, including friction wheels between the
secondary collector and the boiler tube, a stationary member on the
boiler tube with a movable arm, etc. Any method that allows the
secondary collector sections to move, preferably simultaneously or
in a coordinated manner.
[0033] The secondary collector is preferably moved periodically to
constantly point towards the sun throughout the day and or seasons,
or more correctly, the mouth of the secondary collector is pointed
directly away from the sun. In theory the trough is aligned
parallel to the track of the sun and the collector will only have
to be turned slightly each morning. However, this ability to rotate
will also provide a correction mechanism for a misaligned trough or
one that has shifted. Of course, one could also build an alignment
adjustment mechanism into the trough connection to the static
structure ("building") to make slight alignment adjustments to the
positioning of the primary collector trough during or after
installation.
[0034] One preferred mechanism for tracking the sun involves
placing a small hole 154 through the top solar collector 152 or at
a break therein. By providing light sensors, photovoltaic sensor
strips, charged capacitor devices or similar devices that can
determine when the sun points at a position other than directly on
line, the location of the light on the detectors around the target
can be used to determine the current position of the secondary
collector relative to the sun, such as by comparing measurements on
various sensors. This information can be used to determine how to
re-aim the secondary collector to maximize collection of the solar
energy while minimizing the shadowing of the collector on the
primary collector. Additionally or as an alternative, a daily
estimation or annual historical data table can be used to pre-move
the secondary collector a set amount for the day or for that
particular day. Preferably energy collected and/or stored from the
secondary solar cells such as those on the wings 148 and/or solar
collector 152 of the secondary collector are used to rotate the
secondary collector, but one skilled in the art would appreciate
that other sources of power could be used. The energy derived from
the solar panels 148, 152 can also be used to run pumps, such as
for the fluid(s) in the boiler tube, or for other purposes.
[0035] The fluid in the boiler tube is thus heated to a maximum
amount and can be circulated through an appropriate system to
utilize the fluid to generate electricity, run air conditioning or
heating systems, to heat water or for other purposes. By
efficiently directing solar energy onto the boiler tube, solar
energy can be used more efficiently than present systems. The exact
usage of the fluid heated by the present system is elective and
should not be used to limit the claims of the present
application.
[0036] While this invention has been described as having a
preferred design, it is understood that it is capable of further
modifications, uses and/or adaptations of the invention following
in general the principle of the invention and including such
departures from the present disclosure as come within the known or
customary practice in the art to which the invention pertains and
as maybe applied to the central features hereinbefore set forth,
and fall within the scope of the invention and the limits of the
appended claims. It is therefore to be understood that the present
invention is not limited to the sole embodiment described above,
but encompasses any and all embodiments within the scope of the
following claims.
* * * * *