SOLAR HEAT COLLECTING DEVICE

Abstract: A device (20) for collecting solar heat comprises an elongate light-permeable body (21) having a constant converging lenticular transverse section having an optical centre. The optical centre, produced longitudinally of the body (21) defines an optical axis and an elongate hollow member (23) is disposed parallel with the said optical axis and is spaced therefrom by the focal length of the said section. The member (23) is interposed in a fluid-circulation system. In one example, the body (21) is a cylinder and the member (23) has a concave semi-cylindrical plate (22) at a radius equal to the focal length of the section. In this example, light converges to a general focus on what may be termed a focal axis which gradually sweeps over the plate (22). The device (20) may form part of an assembly of such devices arranged as a solar panel.

Description: - 1 - ING_ EVICE DESCRIPTION This invention relates to a device for collecting solar heat . Such devices are used primarily to heat water, and hitherto have usually been in the form of panels wherein water in a flat hollow panel receives heat through a light-permeab Le cover. However, the temper¬ ature of the water cannot be raised appreciably with such devices. High temperature solar collectors have been developed with mirrors. Essentially the mirror forms a large lens concentrating the Light from the sun into a point focus and it is possible to melt metals. It is, however, economically impractical to make use of mirror Lenses in smaller installations. In accordance with the present invention, there is provided a device for collecting solar heat, compri¬ sing an elongate light-permeable body of constant converging lenticuLar transverse section having an optical centre which, produced longitudinally of the tody, defines an opt cal axis along which light and heat from sun light may be concentrated. Embodiments of the invention, will now be described, by way of example, with reference to the accompanying drawings, in which:- Figs. 1,2 and 3 are respectively, a side elevation, a front elevation and a plan of a device according to a first embodiment of the invention; Figs. 4 and 5 are sections on the line A-A of Fig. 1 diagrammatically illustrating conditions at 9.00 a.m. and noon; Fig. 6 is an isometric view of a solar panel with its casing removed and comprising an assembly of devices according to Figs. 1 to 5; Figs. 7 to 11 are views corresponding respectively to Figs 1 to 5 of a device according to a second embodiment of the invention Fig. 12 is a view, corresponding to Fig. 6 compri¬ sing an assembly of devices according to Figs 7 to 11; Figs. 13 to 17 are view corresponding respectively to Figs. 1 to 5 and also respectively to Figs. 7 to 11 of a device according to a third embodiment of the i nventi on; Fig. 18 is identical with Figs 16 to 17 but diagrammatically illustrating conditions at 3.00 p.m.; and Fig. 19 is a view corresponding to Figs. 6 and 12 comprising an assemlby of devices according to Figs. 13 to 18. In Figs. 1 to 5, a device 20 for collecting solar heat comprises an elongate Li ght-per eab Le body of constant converging lenticuLar transverse section. The body is in the form of a cylinder 21 which may be solid or hollow and filled with liquid. The transverse section is, of course, circular and has an optical centre which is the centre of the circle. The optical centre of the section, produced longitud nally of the body, defines an optical axis which is the axis of the cylinder 21. Sun light incident upon one side of the cylinder refracts and converges the Light to a light and heat concentration or general focus on what may be termed a focal axis parallel with the optical axis and spaced therefrom by the focal Length of the section. The device also comprises an elongate hollow member 23 parallel with the said optical axis and having a concave semi -cyLi ndri ca I plate 22 coaxial with the cylinder 21 at a radius equal to the focal length of the section. The plate 22 is heat-permeable so that heat from sun Light is concentrated on the focal axis which gradually sweeps over the plate 22 as the hours of sun Light progress (as shown in Figs 4 and 5 ) and s transferred to the interior of the member 23. The member 23 is interposed in a fluid-circulation system so that the fluid in the member 23 is heated during the - 3 - hours of sun light. As. shown in Fig. 1, the device is hinged at 24 so that its inclinatton can be adjusted according to the latitude of its location on the earth and the time of year so as to optimise its reception of solar heat. Fig. 6 shows a solar comprising an assembly of the devices shown in Figs. 1 to 5. A casing of the panel is not shown but a backing of heat-insulating material for the members 23 is shown at 25. The solar panel is shown facing south as would be appropriate for location in a northern latitude. In Figs. 7 to 11, the hollow member 23 is a tube which is coupled to the cylinder 21 by arms 26 so as to sweep about the axis of the cylinder 21 with the focal axis. In Fig.12 the arms 26 are shown gauged to a rod 27 so as to move in unison under the control of a 24 hour ti ing mechanism 28. Otherwise, the device shown in Figs. 7 to 11 is similar to the device shown in Figs. 1 to 5 and the solar panel shown in Fig. 12 is similar to the solar panel shown in Fig. 6 In Figs. 13 to 18, the hollow member 23 is again a ti^e s in Figs. 7 to 11, but the cylinder 21 is replaced by an elongate I i ght-permeab Le body 29 which may be solid or hollow and filled with liquid, the transverse section of which is similar to the diametral section of a double-convex lens (as shown in Figs, 16, 17 and 18) or other converging lens. This section produces a more clearly defined focus than a circular section but requires to be moved so as to remain directly facing the sun light. Thus, the body 29 is arranged to move with the arms 26 about the axis of the body 29 otherwise, the device shown in Figs. 13 to 18 is similar to the device shown in Figs. 7 to 11 and the solar panel shown in Fig. 19 is similar to the solar panel shown in Fig. 12. The device as shown in Figs. 1 to 5, 7 to 11 or 13 to 18 can be made and used aLone in various sizes for various purposes. In its Larger sizes the heat OM - 4 - generated could be sufficient to create steam power, for desalination of sea water and for fractional d stillation. The linear concentration of heat could be used to heat a roasting spit instead of an eLongate hollow member. Furthermore, the solar panel shown in Figs, 6, 12 or 19 could be used without the elongate hollow members as a drying chamber for industrial purposes . - mTΪE OMP

Claims: CLAIMS 1. A device for collecting solar heat, comprising an elongate light-permeable body of constant converging lenticular transverse section having an optical centre which, produced longitudinally of the body, defines an optical axis along which light and heat from sun light may be concentrated. 2. A device according to claim 1, also comprising an elongate hollow member parallel with said optical axis and spaced therefrom by the focal length of the con¬ verging lenticular transverse section of the body, the hollow member being interposed in a fluid- circulation system. 3. A device according to claim 2, wherein the body is a cylinder. 4. A device according to claim 2, wherein the trans¬ verse section of the body is similar to the diametral section of a double-convex lens. 5. A device according to claim 3, wherein the elongate hollow member has a concave semi-cylindrical plate coaxial with the cylinder at a radius equal to the focal length of the section. 6. A device according to claim 3, wherein the elongate hollow member is a tube arranged to sweep around the axis of the cylinder. 7. A device according to claim 4, wherein the elongate hollow member is a tube coupled with the member to move together around the axis of the member. 8. A solar panel comprising an assembly of the devices each according to claim 1, 2, 3 or 4. 9. A solar panel according to claim 8, wherein the devices are each according to claim 5 and the hollow elongate members are backed with heat-insulating material. 10. A solar panel according to claim 8, wherein the devices are each according to claim 6 and the tubes are coupled together to move in unison around the axes of the respective cylinders. 11. A solar panel according to claim 8, wherein the devices are each according to claim 7 and the tubes and the bodies are coupled together to move in unison around the axes of the respective bodies. 12. A solar panel according to claim 8, 9, 10 or 11, which is hinged so that its inclination can be adjusted. OMPI

Inventors: MACINTYRE ROBERT HAMILTON, MACINTYRE, ROBERT, HAMILTON
Applicants: MACINTYRE ROBERT HAMILTON, MACINTYRE, ROBERT, HAMILTON
Application year: 1983
Main classification: F24J3
IPC codes: F24J2