GB2024407A

GB2024407A - Improvements in or relating to solar heat absorbing panels

Info

Publication number: GB2024407A
Application number: GB7921990A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-06-26
Filing date: 1979-06-25
Publication date: 1980-01-09

Abstract

The object of the invention is to provide a solar heat absorbing panel. The heat absorbing panel comprises a support sheet (10) of glass reinforced plastics material to which are secured first and second panel members (13, 14) of glass reinforced plastics material and a glazing sheet 21 of glass. An insulating layer is secured between the support sheet (10) and the second panel member (14). The panel members are moulded to provide orifices which may be used as outlets from or inlets to allow fluid to be passed between the panel members (13, 14). The first panel member (13) is translucent, and the second panel member (14) is black so that radiation impinging on the panel passes through the glazing sheet (21) and the first panel member (13), into fluid passing between the panel members (13, 14), and finally to the black second panel member (14) which absorbs radiation and is heated. Uses of the heat absorbing panel include the heating of water for domestic water systems or for swimming pools. <IMAGE>

Description

SPECIFICATION Improvements in or relating to heat absorbing panels The invention relates to heat absorbing panels for absorbing energy in the form of electromagnetic radiation, for example soiar energy, to heat a fluid, for example water.

According to the invention there is provided a heat absorbing panel comprising first and second panel members sealed to one another, and inlet and outlet means to allow fluid to be passed between the panel members, the first panel member being of translucent material to allow radiation to pass therethrough and the second panel member being black to absorb radiation energy impinging thereon.

The first and second panel members are preferably of glass reinforced plastics material, and may be planar.

The first and second panel members may lie against one another when fluid is not present between the panel members.

The support means preferably comprises a support sheet having side walls, preferably of glass reinforced plastics material, the panel members being secured at their periphery to side walls of the support panel so that the second panel member is adjacent the support sheet.

A layer of insulating material, for example foam material, is preferably arranged against the second panel member on that side thereof remote from the first panel member.

The panel members and the support sheet are preferably secured together by screws passing through the panel members and engaging the support sheet. The support sheet may include a reinforcing strip, preferably of metal, for engagement by the screws.

The panel may further comprise a glazing sheet arranged parallel to the panel members and adjacent the first panel member to provide an air gap between the first panel member and the glazing sheet.

By way of example, two embodiments of a heat absorbing panel according to the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a sectional side view of the first embodiment of a heat absorbing panel, Figure 2 is a sectional side view of an edge arrangement of the heat absorbing panel of Figure 1, Figure 3 is a sectional side view of a second embodiment of a heat absorbing panel, and Figure 4 is a sectional side view of an edge arrangement of the heat absorbing panel of Figure 3.

As shown in Figures 1 and 2, a heat absorbing panel comprises a support sheet 10 of glass reinforced plastics material which has a planar base portion rectangular in plan and stepped side walls two of which are indicated at 11 and 12.

A translucent first panel member 13 and a black second panel member 14 both rectangular and both of glass reinforced plastics material are secured to a first stepped portion 1 5 of the support sheet 10. The panel member are approximately 1/1 6 inch thick, although other thicknesses could be used. The panel members 13 and 14 are secured to the support sheet by screws 1 6 the heads of which engage an aluminium strip 18, pass through holes in the panel members 13 and 14 and engage an aluminium strip 17 embedded in the support sheet 10. It will be appreciated that an alternative arrangement could be used to secure the panel members to the support sheet 10.

The panel members 13 and 14 are sealed to one another by a peripheral strip of mastic 19, and between the second panel member 14 and the support sheet 10 is secured, preferably by adhesive, an insulating layer 23 of foam or other suitable material.

At the corners of the panel, the panel members 13 and 14 are moulded to each provide half of cylindrical opening so that, when assembled, four openings are provided. The openings act as inlets or outlets for fluid, for example water for domestic use or swimming pool water, to be passed circulated through the panel between the panel members 1 3 and 14.

To a second stepped portion 20 of the support sheet 10 is sealed a rectangular glazing sheet 21 which may be of glass or translucent glass reinforced plastics material. The glazing sheet 21 is sealed to the support sheet by mastic and creates an air gap 22 to insulate the panel members 13 and 14 from the atmosphere and thereby prevent heat losses from the panel members 13 and 14.

Figures 3 and 4 show a second embodiment of a heat absorbing panel. The embodiment of Figures 3 and 4 is generally similar to the embodiment of Figures 1 and 2, but the securing arrangement of the panels is different. In Figures 3 and 4 reference numerals the same as those in Figures 1 and 2 will be used to indicate like parts, but the numerals of Figures 3 and 4 are primed.

As shown in Figures 3 and 4, the black second panel member 14' continues beyond the periphery of the translucent first panel member 1 3' to provide side walls 11' to which is secured the glazing sheet 21'. Thus the second panel member 14' provides the structural base for the heat absorbing panel, instead of the support sheet 10 of the first embodiment. The first panel member 13' of the second embodiment is secured to the second panel member 14' by screws 16', and peripheral sealing is effected by a layer of mastic 19'.

The insulating layer 23' is held in position behind the second panel member 14' by a sheet 24' of flexible polymeric material, such as polyethylene, secured to the second panel member 14'.

In use, the panel is positioned to be exposed to radiation from the sun and connected to a water circuit comprising a tank, an inlet pipe leading- from the tank to the panel, and an outlet pipe leading from the panel to return water to the tank.

A pump may circulate water around the circuit.

The inlet to the panel is arranged at a base corner so that space between the panel members 13 and 14 is occupied before water reaches the outlet.

Although the panel members 13 and 14 lie against one another with no fluid present, when fluid is circulated in the system, fluid pressure causes the panel members to separate.

Radiation from the sun impinging on the panel is able to pass through the glazing sheet 21 and first panel member 13 without significant loss.

The radiation then reaches the circulating water and imparts to it some energy before reaching the black second panel member 14. The member 14, being black, absorbs the remaining energy and is heated. Due to contact between the member 14 and the water, the water is heated; the insulation layer 23 minimising heat loss from the member 14. Heat loss from the first panel member 13 is minimised by the sealed air gap 22.

The panels, in use in a building, are arranged to be fitted in a roof in such a way that the glazing sheet 21, 21' is flush with the surface of the roof.

Such a fitting is achieved by providing a hole of the required panel size in the outer roof covering and inwardly extending flashing at an angle to the roof surface corresponding to the angle at which the side walls 11, 11' lie to the general plane of the panel.

The advantages of these embodiments of the invention are firstly that heat is absorbed actually inside the water chamber and does not rely completely on conduction into the water, and secondly that the arrangement allows use to be made of cheap and easily manufactured and shaped material.

Claims

1. A heat absorbing panel comprising first and second panel members sealed to one another, and inlet and outlet means to allow fluid to be passed between the panel members, the first panel member being of translucent material to allow radiation to pass therethrough and the second panel member being black to absorb radiation energy impinging thereon.

2. A heat absorbing panel as claimed in claim 1 further comprising a layer of insulating material against the second panel member and on that side of the second panel member remote from the first panel member.

3. A heat absorbing panel as claimed in claim 1 or claim 2 in which the first and second panel members are of glass reinforced plastics material.

4. A heat absorbing panel as claimed in any preceding claim further comprising a glazing sheet arranged parallel to the panel members and adjacent the first panel member to provide an air gap between the first panel member and the glazing sheet.

5. A heat absorbing panel as claimed in nny preceding claim in which the first and second panel members lie against one another when fluid is not present between the panel members.

6. A heat absorbing panel as claimed in any preceding claim comprising a support sheet having side walls, the panel members being secured at their periphery to the side walls of the support sheet so that the second panel member is adjacent the support sheet.

7. A heat absorbing panel as claimed in claim 6 in which the support sheet is of glass reinforced plastics material.

8. A heat absorbing panel as claimed in claim 6 or claim 7 in which the panel members are secured to the support sheet by screws passing through the panel members and engaging the support sheet.

9. A heat absorbing panel as claimed in claim 8 in which the support sheet has a peripheral reinforcing strip for engagement by the screws, a further reinforcing strip being arranged on the side of the first panel member away from the support sheet, the heads of the screws engaging the further reinforcing strip.

1 0. A heat absorbing panel substantially as hereinbefore described with reference to and as shown in Figures 1 and 2 or in Figures 3 and 4 of the accompanying drawings.

11. A fluid heating system comprising a tank, a heat absorbing panel as claimed in any preceding claim, pipes connecting the panel and the tank and means to circulate fluid through the panel

12. A building comprising a fluid heating system as claimed in claim 11 in which the heat absorbing panel is recessed in the roof such that the outermost surface of the heat absorbing panel lies flush with the roof surface.