GB1591808A

GB1591808A - Solar energy collector panels

Info

Publication number: GB1591808A
Application number: GB2651/77A
Authority: GB
Original assignee: Pearce F H
Current assignee: Pearce F H
Priority date: 1978-03-01
Filing date: 1978-03-01
Publication date: 1981-06-24

Description

(54) SOLAR ENERGY COLLECTOR PANELS (71) I, FRANCIS HUXHAM PEARCE, a British subject of West Brinsea Farm, Congresbury, Avon, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to solar energy collector panels and to equipment associated with solar energy collector panels.

Solar energy collector panels are known in which a liquid hazing a freezing point below 0 C is circulated. Such panels are provided with heat exchangers which facilitate the exchange of thermal energy between the circulating liquid and a domestic hot water system, for example. These heat exchangers are not as efficient as might be desired, but they are necessary because water circulating directly from a domestic supply would freeze in ambient temperatures of or below 0 C. Such freezing could produce fracturing of pipes supplying a panel, or of the panel itself.

According to one aspect of the present invention there is provided a solar energy collector panel provided with means for accommodating expansion upon freezing of a liquid flowing in the panel in use of the panel, the means comprising resilient, flexible, cellular material of closed cell construction. The means could be in the form of a cord or strip. Such a cellular material could be rubber or a synthetic plastics material, preferably silicone rubber or neoprene.

The solar energy collector panel could comprise a front panel, a back panel and means for accommodating expansion upon freezing of a liquid flowing through the collector panel in use of the collector panel, the front and back panels being arranged such that passageways are provided for a liquid to flow through the collector panel, said means being accommodated in these passageways and comprising resilient, flexible, cellular material of closed cell construction.

Alternatively, the solar energy collector panel could comprise a front panel, a back panel and means for accommodating expansion upon freezing of a liquid flowing through the collector panel in use of the collector panel, the front and back panels being fastened together to provide a cellular or "eiderdown" arrangement, said means being acccommodated inside the arrangement and comprising resilient, flexible, cellular material of closed cell construction. The cellular material could be a foamed rubber or a synthetic plastics material. Suitable foamed rubber could be a neoprene, a polymer of epichlorhydrin, or silicone rubber.

Preferably, the front and/or back panel could be made of a plastics, stainless steel, coated steel, or copper material. The front and back panels could be fastened together by bolts, rivets or other fastening means or they could be fastened together at their peripheries by turning over together of their respective peripheral regions.

Such solar energy collector panels could be provided with coupling means for the supply of a liquid to the collector panel, the coupling means comprising an angled fitting having a flange adapted to form a seal with said means for accommodating expansion.

Such a solar energy collector panel could be provided with a protective cover arranged to protect the panel from weather and reduce heat loss from the front of the panel in use of the panel, the cover comprising a clear or translucent plastics dome and could be provided with flanges to facilitate fitting of the cover over the collector panel.

Preferably, there could be a channel formed in one flange of the cover for drainage purposes.

In the case where the cover comprises a clear or translucent plastics dome, such a dome could be formed from a single piece of plastics material.

According to a second aspect of the invention there is provided a solar energy collector panel comprising a sheet or plate, two or more tubes in thermal contact with the sheet or plate, an inlet manifold, and an outlet manifold, one end of each tube communicating with the inlet manifold and the other end communicating with the outlet manifold, wherein at least one of the manifolds is provided with means for accommodating expansion upon freezing of a liquid flowing through the tubes in use of the panel, the means comprising resilient, flexible, cellular material of closed cell construction.

The means could conveniently be a foamed rubber material. The sheet or plate of such a solar collector panel could be made of a material of good thermal conductivity, such as copper or aluminium. Each tube of such a collector panel could preferably have only one curved portion.

A solar energy collector panel according to the second aspect of the invention could be provided with a protective cover as defined above.

The present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a cross-section through part of a solar energy collector panel provided with passageways, Figure 2 shows a front elevation of the solar energy collector panel shown in Figure 1, Figure 3 shows a cross-section through part of a solar energy collector panel of cellular or "eiderdown" construction, Figure 4 shows a front elevation of the solar energy collector panel shown in Figure 3, Figure 5 shows a cross-section through one example of coupling means and part of a solar energy collector panel, Figure 6 shows a cross-section through another example of coupling means and part of a solar energy collector panel, Figure 7 shows a cross-section transverse the longitudinal axis of one example of a protective cover for a solar panel, fitted over such a panel on a roof, Figure 8 shows a cross-section along the longitudinal axis of one end of the protective cover shown in Figure 7 fitted on a roof, Figure 9 shows a plan view of another example of a protective cover fitted on a roof, Figure 10 shows a cross-section along the longitudinal axis of one end of the protective cover shown in Figure 9 fitted on a roof, Figure 11 shows a front elevation of a solar collector panel provided with inlet and outlet manifolds, and Figure 12 shows a cross-section through one manifold and part of the solar energy collector panel shown in Figure 11.

Referring to Figure 1, a solar energy collector panel comprises two metal sheets - a front sheet 1 and a back sheet 2. The back sheet 2 comprises a flat sheet of thin gauge stainless steel and the front sheet comprises a sheet of stainless steel formed to the shape shown in Figure 1. A layer of foamed rubber 3 is sandwiched between the sheets 1 and 2.

The back sheet 2 is carried by a mild steel backplate 4. The sheets 1 and 2 and the layer of foamed rubber 3 are clamped together by means of bolts or rivets (not shown) applied between the backplate 4 and the mild steel front frame members 5. The bolts or rivets pass through corresponding fixing holes 6 in the sheets 1 and 2, the layer of foamed rubber 3 and the backplate 4 and front members 5.

The layer of foamed rubber 3 is compressed at the points 7 around the fixing holes 6 where pressure is applied by the bolts or rivets. Elsewhere, the layer of foamed rubber 3 is allowed to assume its normal shape due to the curvatures of the formed front sheet 1. Passageways 8 are formed between the layer of foamed rubber 3 and the internal curved surfaces of the front sheet 1.

Referring to Figure 2, a plurality of parallel mild steel front frame members 5 are arranged at regular intervals transverse the front sheet 1 of the panel such that a plurality of the passageways 8 shown in Figure 1 are produced which extend across the solar collector panel.

Such frame members 5 are also aranged around the periphery of the front sheet 1.

A passageway 8 extends along each of the longest sides of the panel, between the respective peripheral frame members 5 and the plurality of frame members 5 transverse the panel.

The fixing holes 6 for the bolts or rivets (not shown) are located at regular intervals along the frame members 5.

An inlet and an outlet (not shown), for a liquid supply to the panel, are provided at the back of the panel at respective ones of two connection positions 9 located at diagonally opposite corners of the panel.

In use of the panel, water is supplied via the inlet at one of the connection positions 9 and circulates in the panel before being conveyed away via the outlet at the other con nection position 9. The water circulates along the passageways 8, the compressed regions of the layer of foamed rubber 3 under the frame members 5 effectively forming gaskets between the sheets 1 and 2.

Referring to Figures 3 and 4, pressed sheet metal front and back sheets, 10 and 11 respectively, are clamped with a layer of foamed rubber 12 sandwiched between them. Both the front sheet 10 and the back sheet 11 have been formed with curved portions such that passageways 15 are produced between corresponding curved portions of the sheets 10 and 11. The layer of foamed rubber 12 is free to assume its normal shape in these passageways 15. Elsewhere, at respective peripheries of the sheets 10 and 11 - which are folded together to produce rolled edges 14 - and at fixing centres 13, the layer of foamed rubber 12 is compressed. The fixing centres 13 each comprise, for example, a nut and bolt, the bolt passing through corresponding holes in the sheets 10 and 11 and the layer of foamed rubber 12, and two washers, each bearing against a respective side of the assembly.

The fixing centres 13 are arranged, as shown in Figure 4, to produce a solar energy collector panel having a cellular or "eiderdown" construction.

In Figure 5, the coupling means for the supply of liquid to a solar energy collector panel comprises a connector tube 16 adapted to fit an opening in a back sheet 17 of a panel.

The tube 16 is provided at one end with an angled flange 22 arranged to overlap the opening in the back sheet 17 to bear against a foamed rubber layer 18 carried by the back sheet 17. The tube 16 is guided and secured to the panel by means of an outer sleeve 19.

This sleeve 19 is also angled, such that the coupling means enters the panel at an angle of about 25 to 30 with respect to the panel.

The flange 22 of the tube 16 and the sleeve 19 are held fast with the foamed rubber layer 18 and the back sheet 17 respectively by means of an internally threaded back-nut 20 carried by an externally threaded length of the tube 16. Liquid is conveyed to or from the panel via the tube 16. Compression of the foamed rubber layer 18 between the flange 22 and the back sheet 17 produces a gasket thus sealing the coupling means with the panel.

Referring to Figure 6, an end of a standard copper tube 23 is terminated with a boss 24.

The boss 24 is drilled to receive the tube 23 such that it forms an angle of about 25 to 30 with respect to the latter. The tube 23 and the boss 24 are soldered or brazed together.

The boss 24 is provided with a flange which is adapted to overlap an opening in a back sheet 25 of a solar collector panel when fitted.

This flange bears against and compresses, over an annular region 27, a foamed rubber layer 26 carried by the back sheet 25. The boss 24, and hence the tube 23, are held fast with the panel by means of an internally threaded backnut 28 which is carried by an externally threaded portion of the boss 24. A gasket is produced by the flange of the boss 24 in the annular region 27 in a manner similar to that of the coupling means described with reference to Figure 5.

The angled fitting of the coupling means described with reference to Figures 5 and 6 permits adequate venting of solar energy collector panels to which they are fitted. Such coupling means also allow rotation of the solar energy collector panel to which they are fitted, with respect to pipes conveying liquid to and from the panel via the coupling means. This rotation facilitates the location of the solar energy collector panel in the desired position during installation.

In Figures 7 and 8, a protective cover 40 is shown fitted on a roof over a solar energy collector panel 41 (indicated by a broken line).

This cover 40 is made of a single piece of clear plastics material. The cover 40 and the panel 41 are carried by battens 42 which are supported by the roof rafters 43, usually with an intervening layer of felt.

The cover 40 is provided with a flange 46 around its periphery, which flange 46 bears against the battens 42. The portion of the flange 46 which is provided along the side of the cover 40 nearest the apex of the roof is wider than the other portions of the flange 46 and extends underneath roof tiles 48 which are tilted by means of an additional batten 44 bearing against the upper surface of the flange 46. The width of this wider portion of the flange 46 is determined according to the longest batten gauge (the distance between adjacent battens on the roof) likely to be encountered.

The cover 40 is fitted on the roof such that the lower portion of its flange 46 substantially abuts the course of tiles 48 running below the cover 40. A strip 45 of proprietry self-adhesive flashing material (weathering strip) is attached across the upper surfaces of the flange 46 and tiles 48 along this lower edge.

The cover 40 is provided with an integral channel 48 formed in each of its portions of the flange 46. A cross-section of one of these side channels 49 is shown in Figure 8. The remaining outer part of the side portions of the flange 46 act as lips 52. These lips 52 bear against feathering strips 50 which are carried by and fixed to the battens 42. These strips 50 comprise timber battens which tilt tiles 48 running adjacent respective sides of the cover 40 and provide the necessary depth for the side channels 49. The cover 40 is held fast with the roof by fixing means passing through the lips 52.

Referring to Figures 9 and 10, another example of a protective cover 60 for a solar energy collector panel is provided at its periphery with a flat flange 61. This flange 61 is supported by roof battens 64. Feathering strips 62 comprising timber battens are fixed over flange 61 above each roof batten 64 to provide a fixing for the roof tiles 65. Weathering is provided by means of shaped water shedding pieces 63 made of a plastics or metal material.

These pieces 63 are tightly sandwiched between the feathering strips 62 and the flange 61, and are fixed to the flange 61 with a suitable sealant. The sides of these pieces 63 which are perpendicular to the flange 61 and which face the apex of the roof are angled such that any water is shedded towards the cover 60.

Protective covers for solar energy collector panels, such as those described with reference to Figures 7 to 10, may be fitted to most existing roofs without necessitating the cutting of rafters, battens, felting or, in some cases, tiles. Such covers also permit the connection of water supplies to panels without the pipes carrying these supplies being subjected to potentially freezing outside conditions. Accordingly, solar energy collector panels protected by such covers need not be finished to weather resistant standards. Also, solar collector panels provided with means for accommodating expansion upon freezing of a liquid flowing in them may be supplied with ordinary water without the risk of frost damage, the supply pipes being suitably insulated or protected.

Such a supply of ordinary water could be taken directly from and returned to a domestic hot water system, for example.

Referring to Figures 11 and 12, an absorber sheet 70 made of a material having a good thermal conductivity, such as copper or aluminium, has several metal tubes 71 arranged over it. These tubes 71 are attached to the sheet 70 such that they make good thermal contact with it.

Each one of the tubes 71 has, at most, one curved portion 73 along its length. Respective ends of the tubes 71 are coupled with inlet and outlet manifolds 72 which are located in opposite comers of the sheet 70. These manifolds 72 are each provided with a connection 76 for an external water supply. These connections 76 are made to the manifolds 72 such that the air is naturaly expelled through the higher connection.

The manifolds 72 each comprise a chamber 75 provided with a layer of foamed rubber 74 (see Figure 12).

In use, any ice forming in the tubes 71, when the panel is subjected to freezing conditions, causes displacement of water towards the manifolds 72 in which the increase in water volume is accommodated by compression of the layer of foamed rubber 74.

WHAT I CLAIM IS: 1. A solar energy collector panel provided with means for accommodating expansion upon freezing of a liquid flowing in the panel in use of the panel, the means comprising resilient, flexible, cellular material of closed cell construction.

2. A solar energy collector panel according to claim 1, wherein said means is in the form of a cord or strip.

3. A solar energy collector panel according to claim 1 or 2, wherein the cellular material is a rubber or a synthetic plastics material.

4. A solar energy collector panel according to claim 3, wherein the cellular material is silicone rubber or neoprene.

5. A solar energy collector panel comprising a front panel, a back panel and means for accommodating expansion upon freezing of a liquid flowing through the collector panel in use of the collector panel, the front and back panels being arranged such that passageways are provided for a liquid to flow through the collector panel, said means being accommodated in these passageways and comprising resilient, flexible, cellular material of closed cell construction.

6. A solar energy collector panel comprising a front panel, a back panel and means for accommodating expansion upon freezing of a liquid flowing through the collector panel in use of the collector panel, the front and back panels being fastened together to provide a cellular or "eiderdown" arrangement, said means being accommodated inside the arrangement and comprising resilient, flexible, cellular material of closed cell construction.

7. A solar energy collector panel according to claim 5 or 6, wherein the cellular material is foamed rubber or a synthetic plastics material.

8. A solar energy collector panel according to claim 7, wherein the foamed rubber comprises a neoprene, a polymer of epichlorhydrin, or silicone rubber.

9. A solar energy collector panel according to any of claims 5 to 8, wherein the front and/or back panel is made of a plastics, stainless steel, copper material, or coated steel.

10. A solar energy collector panel according to any of claims 5 to 9, wherein the front and back panels are fastened together by bolts, rivets or other fastening means.

11. A solar energy collector panel according to any of claims 5 to 9, wherein the front and back panels are fastened together at their peripheries by turning over together of their respective peripheral regions.

12. A solar energy collector panel according to claim 10 or 11, wherein a seal is provided between the front and back panels, the seal being formed by a part of the means for accommodating expansion.

13. A solar energy collector panel according to any of claims 5 to 12, wherein there is provided coupling means for the supply of a liquid to the collector panel, the coupling means comprising an angled fitting having a flange adapted to form a seal with said means for accommodating expansion.

14. A solar energy collector panel according to any preceding claim, provided with a protective cover arranged to protect the panel from weather in use of the panel, the cover comprising a clear or translucent plastics dome.

15. A solar energy collector panel according to claim 14, wherein the cover is provided with flanges to facilitate fitting of the cover over the collector panel.

16. A solar energy collector panel according to claim 15, wherein a channel is formed in one flange for drainage purposes.

17. A solar energy collector panel according to claim 14 or claims 15 and 16 as dependent O.l claim 14, wherein the dome is formed from a single piece of plastics material.

18. A solar energy collector panel comprising a sheet or plate, two or more tubes in thermal contact with the sheet or plate, an inlet manifold, and an outlet manifold, one end of each tube communicating with the inlet manifold and the other end communicating with the outlet manifold, wherein at least one of the manifolds is provided with means for accom

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. by such covers need not be finished to weather resistant standards. Also, solar collector panels provided with means for accommodating expansion upon freezing of a liquid flowing in them may be supplied with ordinary water without the risk of frost damage, the supply pipes being suitably insulated or protected. Such a supply of ordinary water could be taken directly from and returned to a domestic hot water system, for example. Referring to Figures 11 and 12, an absorber sheet 70 made of a material having a good thermal conductivity, such as copper or aluminium, has several metal tubes 71 arranged over it. These tubes 71 are attached to the sheet 70 such that they make good thermal contact with it. Each one of the tubes 71 has, at most, one curved portion 73 along its length. Respective ends of the tubes 71 are coupled with inlet and outlet manifolds 72 which are located in opposite comers of the sheet 70. These manifolds 72 are each provided with a connection 76 for an external water supply. These connections 76 are made to the manifolds 72 such that the air is naturaly expelled through the higher connection. The manifolds 72 each comprise a chamber 75 provided with a layer of foamed rubber 74 (see Figure 12). In use, any ice forming in the tubes 71, when the panel is subjected to freezing conditions, causes displacement of water towards the manifolds 72 in which the increase in water volume is accommodated by compression of the layer of foamed rubber 74. WHAT I CLAIM IS:

1. A solar energy collector panel provided with means for accommodating expansion upon freezing of a liquid flowing in the panel in use of the panel, the means comprising resilient, flexible, cellular material of closed cell construction.

modating expansion upon freezing of a liquid flowing through the tubes in use of the panel, the means comprising resilient, flexible, cellular material of closed cell construction.

19. A solar energy collector panel according to claim 18, wherein the disposition of the tubes is such that at their end regions they converge in their approach to the manifolds.

20. A solar energy collector panel according to claim 18 or 19, wherein the material is a foamed rubber material.

21. A solar energy collector panel according to any of claims 18 to 20, wherein the sheet or plate is made of a material of good thermal conductivity, such as copper or aluminium.

22. A solar energy collector panel according to any of claims 18 to 21, wherein each tube has only one curved portion.

23. A solar energy collector panel according to any of claims 18 to 22, provided with a protective cover as defined in any of claims 14 to 17.

24. A solar energy collector panel, substantially as herein described with reference to Figures 1 and 2 of the accompanying drawings.

25. A solar energy collector panel, substantially as herein described with reference to Figures 3 and 4 of the accompanying drawings.

26. A solar energy collector panel provided with coupling means, substantially as herein described with reference to Figure 5 of the accompanying drawings.

27. A solar energy collector panel provided with coupling means, substantially as herein described with reference to Figure 6 of the accompanying drawings.

28. A solar energy collector panel provided with a protective cover, substantially as herein described with reference to Figures 7 and 8 or 9 and 10 of the accompanying drawings.

29. A solar energy collector panel substantially as herein described with reference to Figures 1 and 2 or 3 and 4 of the accompanying drawings provided with a protective cover substantially as herein described with reference to Figures 7 and 8 or 9 and 10 of the accompanying drawings.

30. A solar energy collector panel, substantially as herein described with reference to Figures 11 and 12 of the accompanying drawings.

31. A solar energy collector panel substantially as herein described with reference to Figures 11 and 12 of the accompanying drawings provided with a protective cover substantially as herein described with reference to Figures 7 and 8 or 9 and 10 of the accompanying drawings.