Solar heating panel fabricated from multi-wall plastic sheets
A solar panel, through which a fluid is circulated, includes a transparent central panel, with a number of channels extending through the panel from one end to another. A manifold is attached to each end of the transparent central panel so that distributing chambers within the manifolds direct the fluid to move between adjacent channels within the central panel. The solar panel additionally includes a transparent support structure above the central panel and a lower support structure below the panel. Dark, opaque material below the central panel absorbs heat and warms the fluid.
This application claims the benefit of U.S. Provisional Application No. 60/920,093, filed Mar. 26, 2007.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTNot Applicable
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates to solar panels, and, more particularly, to solar panels including multi-layer translucent plastic sheets, known as multi-wall sheets, having an array of tunnels formed in the direction of extrusion, through which a fluid flows to be heated by solar radiation.
2. Summary of the Background Art
Solar water heaters have been installed for many years, but have not become very popular because they require a quite large investment, which amortizes over a very long time. Because of the high expenses involved, many people cannot afford such a system, as the return ratio involves excessive time, even when such a project is financed. Since the present designs of the solar water heating panels require materials and equipment that is not readily available in many places worldwide, shipping makes these products even more expensive and out of reach for many people. In particular, prior-art solar panel designs require a heavy frame surrounding flexible panel elements.
What is needed is a low-cost solar water heating panel, that is highly efficient, light weight, easy to handle and can be manufactured in almost any place worldwide.
U.S. Pat. Appl. Pub. No. 2007/0186922 A1 describes a A panel for generating electrical and thermal power comprises an upper layer formed by a translucent sheet having an array of photovoltaic cells and a support structure including a pair of multi-walled translucent sheets, and an underlying reflective sheet. The multi-walled translucent sheets each include a number of elongated channels, with the two sheets being arranged so that their channels lie perpendicular to one another for rigidity. The channels within at least one of the sheets are filled with circulating water, which is heated by solar energy not absorbed within the photovoltaic cells.
SUMMARY OF THE INVENTIONAccording to one aspect of the invention, a solar panel is provided, including a transparent central panel a pair of manifolds, a transparent upper support panel, a lower support panel, a dark, opaque structure extending under the transparent central panel, and a side cover extending upward and downward from each side of the transparent central panel. The pair of manifolds includes a manifold fastened to extend along each end of the transparent central panel. Each manifold includes a plurality of distributing chambers, each of which connects a plurality of adjacent channels within the translucent central panel. The pair of manifolds includes a pair of ports. The distributing chambers are located so that two of the distributing chambers are connected by adjacent channels in the transparent central sheet to one of the ports and to one of the distributing chambers in the manifold at the opposite end of the transparent central panel. and so that each of the remaining distributing chambers are each connected by adjacent channels within the transparent central panel to a pair of adjacent distributing chambers in the manifold at the opposite end of the central transparent panel.
As the terms are used herein, the upper side of the solar panel is the side facing the sun, and the upward direction is perpendicular to the panels within the solar panel, in the general direction of the sun.
The distributing chambers in either of the manifolds may consist of an even number of distributing chambers, with one of the ports being located in each of the manifolds. Alternately, the distributing chambers in either of the manifolds may consist of an odd number of distributing chambers, with both of the ports being located within one of the manifolds.
Both the transparent central panel and the outer support panels may be formed from a plastic multi-wall sheet of uniform thickness including a number of internal, parallel channels. Alternately, the transparent central panel may be formed as an integral part with the side walls, or the support structures may each be formed using a slotted panel having a number of legs adhesively attached to the transparent central panel. The upper support panel and the transparent central panel may include a web having a number of sections shaped to concentrate light within a fluid in the channels within the central transparent panel.
Preferably, each of the manifolds includes at least one dead air space. The manifolds may be attached to the upper and lower support structures by screws extending through clearance holes within edges of the support structures to engage threaded holes within brackets extending within channels in the support structures.
Various internal features of a solar panel 10, built in accordance with a first embodiment of the invention, will now be discussed, with reference being made to
In the example of
Each of the manifolds 18 additionally includes a central outer cavity 30, an outer end cavity 32, and inner end cavities 34, all of which are enclosed by outer walls 36 to form dead-air spaces providing thermal insulation separating the fluid circulating within the solar panel 10 from ambient conditions. Additional thermal insulation is provided by dead air spaces within two outermost channels 38 at each side 39 of the central multi-walled panel 12. Preferably, the manifolds 18 are aligned with the central multi-wall sheet 12 by means of ribs 40 within the manifolds 18 extending into notches 41 within the sheet 12.
Preferably, the solar panel 10 is oriented with a first side 62 facing the sun, and with a first outer multi-wall sheet 64 and the central multi-wall sheet 12 are composed of transparent materials, and with the second outer multi-wall sheet 66 composed of a dark opaque material. In this way, solar radiation is allowed to travel through the multi-walled sheets 64, 12 to heat the fluid 15 within the multi-wall sheet 12, while solar radiation traveling through the multi-wall sheets 64, 12 and the fluid 15 is mostly absorbed within the second outer multi-wall sheet 66 to further heat the fluid 15. Alternately, the lower side 65 of the central sheet 12 may be coated with a dark, opaque material.
Preferably, the fluid 15 is water, which may include additives. For example a pigment may be included to improve the absorption of radiated heat, or an anti-freeze additive may be included to prevent freezing of the fluid 15 during periods when the solar panel 10 is not being used, such as at night. Alternately, the fluid may be another liquid, a gas, or a fluid that changes from a liquid to a gas when heated within the solar panel 10.
Variations in the form of cavities provided to improve the thermal insulation of the fluid 15 within the solar panel will now be discussed, with reference being made to
For example,
For example, the solar panel 90 is oriented with the first outer multi-wall sheet 96 facing the sun, with the first outer multi-wall sheet 96 and the central multi-wall sheet 95 being composed of a transparent material, and with the spacing multi-wall sheet 100 being composed of a dark opaque material. The space 112 provides an air space, through which radiant energy easily travels inward, in the direction of arrow 114 to warm the fluid 15, while a convective or conductive flow of heat outward, opposite the direction of arrow 114 is largely prevented. The opaque spacing sheet 100 absorbs radiant energy, additionally warming the fluid 15.
Alternately, the solar panel 90 is oriented with the second multi-wall sheet 98 facing the sun, with the multi-wall sheets 98, 100, and 95 all being composed of a transparent material, allowing radiant energy to warm the fluid 15, and with the space 112 being filled with an opaque insulating material (not shown)l, which is warmed by exposure to radiant energy, but which prevents the conductive transfer of heat from the warmed fluid 15.
Alternate methods for fastening manifolds to multi-wall sheets will now be discussed, with reference being made to
The concept of providing a web having convex or concave sections to provide a preferred pattern in which radian energy is concentrated can also be applied to the closed channels within a multi-wall sheet 12, 46, or within the central panel structure 190, described above in reference to
It is understood that various features of one embodiment described herein may be readily applied to one of the other embodiments. For example, the central panel structure 190, described above in reference to
While the invention has been described in terms of preferred embodiments and versions with some degree of particularity, it is understood that this description has been given only by way of example, and that many change can be made without departing from the spirit and scope of the invention, as defined in the appended claims.
Claims
1. A solar panel comprising:
- a transparent central panel including a pair of ends opposite one another, a pair of sides opposite one another and perpendicular to the pair of ends, and plurality of channels extending between the pair of ends;
- a pair of manifolds, including a manifold fastened to extend along each end of the transparent central panel, wherein each manifold includes a plurality of distributing chambers, each connecting a plurality of adjacent channels within the plurality of channels in the transparent central panel, wherein the pair of manifolds includes a pair of ports, wherein the distributing channels within the pair of manifolds are located so that two distributing chambers in the plurality of distributing chambers are connected by adjacent channels within the transparent central panel to one of the ports and one of the distributing chambers located adjacent an opposite side of the transparent central panel, and so that the remaining distributing chambers in the plurality of distributing chambers are connected by adjacent channels within the transparent central panel to a pair of adjacent distributing channels adjacent an opposite end of the transparent central panel,
- a transparent upper support panel extending above the transparent central panel to enclose a plurality of dead air spaces above the transparent central panel;
- a lower support panel extending below the transparent central panel to enclose a plurality of dead air spaces below the transparent central panel;
- a dark, opaque structure extending under the transparent central panel; and
- a side cover extending upward and downward from each side of the transparent central panel to engage outer edges of the upper and lower support structures.
2. The solar panel of claim 1, wherein
- all of the distributing chambers in either of the manifolds comprise an even number of distributing chambers,
- each of the manifolds includes one of the ports; and
- the manifolds are formed as identical and oppositely oriented on the ends of the transparent central structure.
3. The solar panel of claim 1, wherein
- all of the distributing chambers in either of the manifolds comprise an odd number of distributing chambers,
- one of the manifolds includes both of the ports.
4. The solar panel of claim 1, wherein the side covers and the transparent central panel are formed as a single, integral part.
5. The solar panel of claim 1, wherein each of the manifolds encloses at least one dead air space.
6. The solar panel of claim 1, wherein the manifolds are attached to the upper and lower support structures by screws extending through clearance holes within edges of the upper and lower support structures to engage threaded holes within brackets extending within channels in the support structures.
7. The solar panel of claim 1, wherein the lower support structure is dark and opaque.
8. The solar panel of claim 1, wherein the upper and lower support panels each comprise a panel including a plurality of channels extending perpendicular to the channels within the transparent central panel.
9. The solar panel of claim 1, wherein the upper and lower support panels each comprise a panel including a plurality of legs adhesively attached to an adjacent surface of the central transparent panel and a web connected to each of the legs to extend along a side of the support panel opposite the transparent central panel.
10. The solar panel of claim 1, wherein upper support panel and the transparent central panel together include a web having a number of sections shaped to concentrate light within a fluid in the channels within the central transparent panel.
11. The solar panel of claim 1, wherein at least one of the support panels is held by side covers spaced away from the transparent central panel.
Type: Application
Filed: Feb 21, 2008
Publication Date: Oct 2, 2008
Inventor: Guenter Schaefer (Coconut Creek, FL)
Application Number: 12/070,792
International Classification: F24J 2/05 (20060101); F24J 2/10 (20060101);