GB2064097A

GB2064097A - Solar Heating Device

Info

Publication number: GB2064097A
Application number: GB7940542A
Authority: GB
Original assignee: Carpools Environmental Protection Services Ltd
Current assignee: Carpools Environmental Protection Services Ltd
Priority date: 1979-11-23
Filing date: 1979-11-23
Publication date: 1981-06-10
Also published as: GB2064097B

Abstract

A solar quilt (1) comprises an upper film (12) of optically transmitting material, its lower surface being reflective to infra-red energy impinging on its underside, and a lower film (14) of non-optically transmitting material, the upper surface of the lower film being rough. The two films form between them a multiplicity of gastight compartments providing a thermal insulation barrier. The quilt has utility in the solar heating of buildings, heat pump collectors, swimming pools and agricultural growing beds. In the last mentioned application the quilt may also be used to extend the growing season and to collect rain and to divert the latter onto the roots of produce. <IMAGE>

Description

SPECIFICATION Solar Heating Device This invention relates to a solar quilt for lengthening the growing season and for drying fruits in argiculture, heating swimming pools and buildings, heating of sewage treatment lagoons and for other industrial and domestic purposes.

It is a feature of one object of the invention to provide a quilt which collects radiant energy and transmits the energy therethrough, but which substantially reduces heat flow in an opposite direction.

It is a feature of another object of the invention to provide a solar quilt suitable for use in heating a swimming pool.

It is a feature of another object in the invention to provide a solar quilt for use in connection with the heating of buildings either directly or in conjunction with heat pumps.

It is a feature of a further object of the invention to provide a solar quilt for raising the temperature of soil and for extending the growing season in agricultural processes, including the drying of produce.

It is a feature of a further object of the invention to provide a solar quilt for use in raising and/or controlling the temperature of sewage lagoons, fishponds, aquaculture areas, and similar examples.

In accordance with the foregoing features, the invention comprises: a solar quilt comprising at least one solar energy receiving and transmitting layer, said layer comprising: i) an upper film of optically transmitting material, said upper film having a high ultraviolet and infrared transmission capability, the upper film having a lower surface which reflects downwardly the infrared energy impinging on the underside of said upper film; ii) a lower film of non-optically transmitting material, said lower film having a high light energy absorption capability and high heat conductivity capability said lower film having an upper surface which is rough, said upper and lower films forming therebetween a multiplicity of isolated gastight compartments providing a thermal insulation barrier between said upper and lower films.

By way of introduction, it is required that a solar quilt be formed to provide a high solar heat absorption capability and high thermoconductivity for transmission of heat from a collector to the medium to be heated. It is further required that the quilt have a high surface area, and be usually buoyant, wear resistant and flexible.

Compromises between weight, thickness, durability, vapour or gas retention, insulation, heat absorption and transmission will all vary with the purpose and cost effectiveness of each application.

Applications include, but are not limited to the following: Solar heating of liquids in all appropriate weather conditions for indoor and outdoor swimming pools, aquaculture and sewage treatment lagoons, or industrial and domestic processes; Solar heating of building surfaces; Solar heating of ground surface and above ground areas for agricultural purposes of all types where appropriate; Insulation purposes with or without solar energy.

The invention will now be described with reference to the accompanying drawings, in which: Figs. 1 and 2 are cross-sectional views of a solar quilt having sinusoidally-shaped pockets therein.

Figs. 3A, 3B and 3C are cross-sectional views of a solar quilt having semi-circular or sphericalshaped pockets therein.

Fig. 4 is an isometric view of a solar blanket having parallel rows of cylindrical pockets therein.

Fig. 5 is an isometric view of a plantation of produce growing in soil which is heated by a solar blanket and wherein pairs of the solar blankets are used to funnel rain onto the produce.

In the following description of preferred embodiments, the words solar quilt, solar blanket, or solar panel are used as appropriate to the utilization of the invention and dependent on whether the device is buoyant, flexible or rigid.

In Fig. 1, a solar quilt comprises an upper film 12 of optically transmitting material and a lower film of non-optically transmitting material. The upper and lower films abut and are sealed to each other at a multiplicity of separated junction points to form a matrix of isolated gastight compartments. The compartments thus formed inherently define an upper film which undulates, for example, sinusoidally, thereby increasing its net surface area. The upper film 12 has a high ultraviolet and infrared transmission capability, and the lower surface of the upper film reflecting downwardly much of the infrared energy impinging thereon from the underside of the upper film, thereby contributing to the "greenhouse" effect.

The lower film 14 has a high light energy absorption capability and preferably, an upper surface which is rough. The upper film 12 may be formed of clear plastics material selected from the group consisting of: nylon, polyolefin (e.g.

Cryovace), polyethylene, (e.g. Molars) and vinyl.

The lower film 1 6 may comprise a plastics or elastomeric material. Thus the film may be formed of a material selected from the group consisting of nylon, polypropylene, polyvinylchloride, and an ionomer resin (e.g.

Surlyns) or natural or artificial rubber.

The lower film 14 may further comprise an upper coating of aluminum, copper, metallic oxide, and/or conductive components in the form of powder, film, solution, or as a mixture on or within the material selected.

In the embodiment shown in Fig. 1, the upper and lower films abut each other at a multiplicity of junction points to form a matrix of isolated gastight compartments.

Essential features of the invention reside in the formation of a multiplicity of gastight compartments, an undulating, pyramidal, hemispherical, cubic, or otherwise non-planar upper film having a net energy receptive area which is greater than its geometric planar area; an upper film which receives therethrough solar energy, a lower film which receives solar energy passing through the upper film and conducts the heat into a medium to be heated.

With further reference to Fig. 1, the quilt 1 may further include a second layer of gastight compartments by the addition of an intermediate film in place of the aforementioned lower film 14 and in which case the lower film will now be represented by item 1 6 in Fig. 1. This intermediate film may be formed of a similar material as that used for the first mentioned upper film 12. Also, one or both of strengthening chemical-resistant or wear-resistant films 10 and 18 may be added. The upper strengthening film 10 must, of course be formed of a material which transmits solar energy. The lower strengthening film 1 8 must be capable of transmitting heat. It is to be understood that the films 12 and 16 may be replaced by a single strengthening film 10 or 18.

The upper and lower films, 10 and 18, respectively, may be formed of a material having a fungicidal and/or bacteriacidal capability or coated or otherwise treated to produce the same or either of the said two capabilities.

In the embodiment of Fig. 2 at least one of two intermediate films 23 and 25 are used, in which case the upper and lower films 22 and 24 or 26 (in the case of a three-layer arrangement) do not abut each other, but abut and are joined to the intermediate films 23 and 25 to form the multiplicity of isolated gastight compartments.

In the embodiment shown in Fig. 3A, the upper film 32A is formed into semihemispherical modules which abut and are sealed to a lower film 34A. An upper strengthening film 30A may be included.

Fig. 3B shows a similar embodiment as that shown in Fig. 3A but wherein the lower film 34B is formed with semihemispherical modules which correspond to and oppose the modules in the upper film 32A. An intermediate planar film 36 may be used.

Fig. 3C shows two layers of the double seminemispherical modules or bubbles and comprises opposed upper bubbles 32C and 34C and opposed lower bubbles 36C and 38C. There may further be included upper 30 and/or lower 35 protective films as in the aforementioned embodiments shown in Figs. 1,2, and 3A. The lower bubbles 34C of the upper layer which abut the upper bubbles 36C of the lower layer are sealed together at the points of abutment.

In the embodiment shown in Fig. 4 the quilt 4 comprises upper bubbles 40 and lower bubbles 42 which are elongate and extend the full width of the quilt. Apart from the elongate bubbles, other variants of the quilt shown in Fig. 4 may be in accordance with embodiments shown in Figs.

1-3C. In this embodiment, the elongate bubbles inherently provide transverse strength so that the quilt may be relatively rigid and may be supported solely along the longitudinal edges of the quilt.

When the quilt 4 is supported in this manner the various elements may, if necessary, be formed of more rigid materials and/or include upper and lower films equivalent to items 10 and 18 in Fig.

1, items 20, 23, 25, or 28, in Fig. 2, and items 30A or 34A in Fig. 3A, etc.

Fig. 5 shows only one example of an agricultural application of the quilt shown in Fig.

4. Rows of quilts, 5A-5F may be arranged, as shown, to form troughs in which produce is planted. The quilts raise the temperature of the ground and promote more rapid growth and extend the growing season. Moreover, any precipitation and condensation from dew is directed towards the produce.

Round, oval, pyramidal or rectangular sections as well as strips of the solar quilt may be used for individual and multiple seeds, plants, vines, or trees. These variations may include structural combinations of the forms shown in Figs. 1-4 where circular sections may be appropriate with radial surface troughs. In this case the junction points between the films are arranged substantially along non-parallel and mutually convergent rows, whereby the overall shape of the quilt is circular, and whereby a plurality of radially disposed drainage troughs is defined.

In each of the aforementioned embodiments the perimeter of the quilt may be formed with a curve having an aerofoil section which stabilizes the edges and creates an oblique pressure when the quilt is subjected to wind or lateral movement across the surface of the quilt.

Examples of other uses would include coverings for eavestroughs, downspouts, sidewalls, etc. in freezing temperatures to control ice formation.

Figures 3C and A show sections adjacent to the solar collector lower film through which fluids may pass for heat absorption.

Price and stability of base materials will vary widely with the life expectancy and durability requirements; from lightweight, economical, low efficiency needs such as met with current household garbage type bag containers, to heavy duty, durable, high efficiency materials for longer term use.

The molecular structure and density of individual plastics, the thickness, the reinforcing such as fibreglass, and the surface or entrained solar collection components are principal factors in the physical characteristics to be included in the structure of the invention.

Selective light ray transmission, absorption, and reflection factors are practical for a wide range of available film materials and cominations.

Metallic, and non-metallic matter such as glass in various forms such as powder, thread, particles, cloth, film or sheet, will become integral components and additions for speciaiized purposes. Coatings and films may be necessary to control vapours and gases within the small compartments, channels or bubbles which form part of the insulating and "greenhouse effect" features of the invention.

The pressure of the vapours and gases within the compartments will vary from partial vacuum to above atmospheric depending on the purpose and function.

The upper layer of layers of light transmitting materials may be constructed from many alternatives such as nylon, vinyl, PVC etc., while the bottom energy absorbing layer may be constructed from alternatives such as latex based or synthetic rubbers; chlorinated polyethylene; Hypalons; Aclars; polypropylene etc. depending upon economics and function and compatibility with additional materials mixed or dissolved to achieve maximum solar energy absorption and/or heat transmission properties. Functions for agricultural purposes would increase the ground temperature by solar energy and at the same time provide insulation for improved temperature conditions for germination and growth plus protection from frost.

Openings and channels may be provided for control and direction of irrigation water or dew, from natural or artificial sources.

Claims

1. A solar quilt comprising at least one solar energy receiving and transmitting layer, said layer comprising: i) an upper film of optically transmitting material, said upper film having a high ultraviolet and infrared transmission capability, the upper film having a lower surface which reflects downwardly the infrared energy impinging on the underside of said upper film; ii) a lower film of non-optically transmitting material, said lower film having a high energy absorption capability and high heat conductivity capability, said lower film having an upper surface which is rough, said upper and lower films forming therebetween a multiplicity of isolated gastight compartments providing a thermal insulation barrier between said upper and lower films.

2. A solar quilt as defined in Claim 1 , wherein said junction points are arranged to form a plurality of recesses in the upper film, said recesses having bases which are substantially interconnected.

3. A solar quilt as defined in Claim 1, wherein said junction points are arranged substantially parallel in rows so as to form a plurality of drainage troughs on the upper surface of said quilt.

4. A solar quilt as defined in Claim 1, wherein one or more intermediate sheets and/or quilt sections of transparent material separate the upper and lower films to provide strength and/or a further thermal insulating barrier.

5. A solar quilt as defined in Claim 1, 2 or 3 further including a coat of wear-resistant material on the upper surface of said upper film.

6. A solar quilt as defined in Claim 1,2 or 3, further including a chemically resistive coat on the upper surface of said upper film.

7. A solar quilt as in Claim 1,2 or 3, further including a coat of unidirectional light transmitting material on the lower surface of said upper film, said said unidirectional light transmitting material having the capability of transmitting solar energy in a downward direction and impeding transmission of thermal energy in the upper direction.

8. A solar quilt as defined in Claim 1,2 or 3, wherein the upper surface of said lower film is roughened to increase the effective surface area thereof.

9. A solar quilt as defined in Claim 1,2 or 3, further including a coat of light energy absorbing material disposed on the upper surface of said lower film.

10. A solar quilt as defined in Claim 1,2 or 3, wherein said lowerfilm is comprised of a thermal conductivity enhancing material.

11. A solar quilt as defined in Claim 1, 2 or 3, wherein said lower film further includes mechanical reinforcement means by addition of higher strength materials.

12. A solar quilt as defined in Claim 1,2 or 3, wherein said quilt is buoyant on liquid.

13. A solar quilt as defined in Claim 1,2 or 3, wherein said quilt is structured to permit rollingup along a selected axis thereof.

14. The solar quilt as defined in Claim 1,2 or 3, wherein the lower film comprises a multiplicity of geometric shapes to increase the effective surface area thereof, in sections of spheres, pyramids, or cubes.

15. The solar quilt as defined in Claim 1,2 or 3, further including a coat on the lower surface of the lower film, said coat on the lower surface having a heat reflective capability.

16. The solar quilt as defined in Claim 1, 2 or 3, said coat on the lower surface of the lower film having an antiabrasive capability.

17. The solar quilt as defined in Claim 1,2 or 3, said coat on the lower surface of the lower film having an anticorrosive capability.

18. The solar quilt as defined in Claim 1, 2 or 3, said coat on the lower surface of the lower film having fungicidal capability.

19. The solar quilt as defined in Claim 1,2 or 3, said coat on the lower surface of the lower film having bacteriacidal capability.

20. The solar quilt as defined in Claim 1,2 or 3, having curved edges forming an airfoil section which stabilizes the edges and creates an oblique pressure when subjected to wind or air lateral movement across the surface of the quilt.

21. The solar quilt as defined in Claim 1,2 or 3, having selected openings in designated positions to permit surface drainage, and also to serve as points for connection.

22. A solar quilt as defined in Claim 1 , wherein said junction points are arranged substantially along non-parallel and mutually convergent rows, whereby the overall shape of the quilt is circular, and whereby a plurality of radially disposed drainage troughs is defined.

23. A solar quilt substantially as herein described with reference to the accompanying drawings.