IE43855B1 - Manifold for a solar energy collecting apparatus - Google Patents

Description

The present invention relates to the collection of solar energy radiated by the sun's rays in a solar collector apparatus and in particular to an elongate manifold for such apparatus.

In accordance with the present invention, there is provided an elongate manifold for a solar energy collector comprising a plurality of pairs of metal cup-shaped members whose open mouths are each defined by respective annular flange portions and which are disposed with the two cup-shaped members in each pair coaxial and back-to-back so as to define two compartments, respectively, which are separated by a transverse partition formed by their bases, the pairs of cup-shaped members being disposed in laterally spaced apart, mutually parallel relation longitudinally of the manifold, with the longitudinal axis of the cupshaped members all lying in a common plane, an inlet header pipe extending longitudinally of the manifold, a first fluid handling conduit connecting the inlet header pipe to at least one of said compartments formed by said plurality of cup-shaped members, an outlet header pipe extending longitudinally of the manifold and spaced from the inlet header pipe, a second fluid handling conduit connecting at least one other of said compartments formed by said plurality of cup-shaped members to the outlet header pipe, means interconnecting the compartments of the cup-3- 42855 shaped members to enable fluid flow therebetween, and a thermally insulating jacket member comprised of a cellular insulating material and surrounding the cupshaped members, the inlet and outlet header pipes and the fluid handling conduits, the jacket member including apertures providing access to the flanged openings of said cup-shaped members for connecting solar collector apparatus externally of the jacket member to the cupshaped members. 1C rhe invention, rs described farther u ex? C ΧΡ. £<.4, t by way of example, with reference to the accompanying drawings, in which:Figure 1 is a perspective view of a solar energy collector apparatus comprised of two modules installed on a support for solar exposure; Figure 2 is a view in perspective, partly broken away, showing one of the solar collector tubes of the apparatus; Figure 3 is a perspective side view of the inner parts of a manifold during fabrication showing the construction of the cups for receiving the collector tubes and the counter flow headers interconnected therewith; Figure 4 is a sectional plan view of the manifold parts shown on Fig. 3, taken along line 4-4 on Fig. 5; Figure 5 is a side elevational view of the manifold parts shown on Fig. 3; Figure 6 is a perspective view, with a portion broken away, showing the insulated manifold section for a modular unit of the collector apparatus; Figure 7 is a fragmentary sectional elevational view of the collector apparatus; Figure 8 is an exploded perspective view showing the interconnection of two modular sections of the manifold; Figure 9 is an exploded perspective view showing an end connection and cap for the manifold Of the collector apparatus; Figure 10 is an exploded perspective view, partly in phantom, outline, showing the mounting bracket for the manifold and its assembly therewith; Figure 11 is a fragmentary end sectional elevational view of the mounting bracket of Fig. 10; Figure 12 is a perspective view of the end cap mounting bracket for supporting the free ends of the array of collector tubes' in the modular collector apparatus; Figure 13 is a perspective interior view of the end cap fastener for attaching the collector tube into the mounting bracket shown on Fig. 12; Figure 14 is an exploded perspective view showing the assembly of a collector tube in the mounting bracket and being retained thereon by the end cap of Fig. 13; and Figure 15 is a schematic diagrammatic view of a heating or cooling system for applying the absorbed solar energy.

In Fig. 1, a plurality of tubular collectors 10, which shall be described in greater detail hereinafter, are connected into a manifold 11. The manifold is supported over a surface that is exposed to solar rays, such as a southerly facing side of a roof on a building, and to increase the efficiency Of operation of the tubular collectors 10, the array thereof is spaced from a backside surface 12 on the roof area that comprises a diffuse-reflecting surface coextensive in area, at least, with the surface area covered by the array of the tubular collectors. The surface 12 may take the form of a white painted surface and may in particular be a matte finish surface, aa compared to a shiny or specular finished surface. The tubular collectors 10 are supported, as a group, above the diffuse-reflecting surface layer 12 by the combination of the manifold 11 and its support bracket elements 13 fastened firmly onto surface 12 together with end support members 14 which fasten and support the closed ends of the collectors 10 at the outwardly dependent closed ends which are opposite the ends connected into manifold 11.

The arrangement of the collectors 10, manifold 11, 13 and end support members 14 comprise a modular unit of the system which is preferably mounted over the diffuse-relector surface 12 in accordance with the teachings of Patent Specification No. 41813.

According to that arrangement, the lateral spacing between the axial centres of the tubular collectors 10, which have a common diametrical dimension, is up to 4 times the outside diameter of the collector 10; and the collectors are supported with their axial centres in spaced relation from the surface 12 and in the direction of the sun an amount that is no greater than 4 times their outer diameter.

By virtue of the system just described, the module may be firmly supported on the roof or curtain wall of a building, or the like, without provision for tracking (angular adjustment) with respect to the sun during the solar day period. However, the present apparatus, as hereinafter described, may very readily be mounted on a support that is movable for a tracking system should such be desirable to use.

The module of the tubular collector array may be arranged with an adjacent similar module in the installation, as is shown on Fig. 1, to provide the area of coverage and collection area desired and designed into a given installation. The module may be constructed with as many tubular collectors as desired, the particular example given on Fig. 1 being a module having thirty-two tubular collectors 10 disposed evenly and in pairs on opposite sides of the manifold 11.

The tubular collector 10 is shown in Fig. 2 in greater detail. This collector 10 is preferably constructed of transparent glass and comprises an outer or cover tube 15 that is circumferentially transparent and open at its one end and closed at the opposite end upon tipping off the tubulation 16, as will be described later herein. The open end wall of the cover tube is sealed to a glass absorber tube 17 near one end of its tubular wall by a glass-toglass hermetic seal 18. This seal is most readily made by fusion of the two glass parts in an annular pattern by heating the glass locally to or just above the softening point. The absorber tube 17 is made of glass and is of somewhat lesser outside diameter and of slightly greater length than the inside diameter and length, respectively, of the cover tube 15. Tube 17 is closed at its one end 17a somewhat like a test tube, and open at its opposite end 17b. Prior to assembly, the external peripheral glass surface of the absorber tube 17 is coated with an opaque layer of an 3 8 5 5 - 7 energy absorbing coating 19 (shown by the shaded area on Fig. 2), which is preferably an overall highperformance, wave length selectively absorbing coating material. Such coatings are commercially available in the optics field. A high performance wave length selective coating constitutes one which is selective in solar radiation having an absorptance property of 0.8 and higher of the wave lengths of 2.5 microns and above, and an infra-red emittance property of 0.1 and ±0 rest. Thus, the coaxing layer 19 has a very high absorptance and very low emittance. Examples of suoh wave length selective coatings are a metallic undercoating of aluminum or silver deposited as a layer on the glass surface; and a semi-conductor type of coating deposited over the metallic layer to provide the wave length sensitivity desired. The open end 17b of the absorber tube is inserted into the manifold, seated and sealed, in a manner to be hereinafter described. The closed, free end 17a of the absorber tube is preferably retained in place near the closed end of cover tube 15 by a coiled spring element 20.

After the tubes 17, 15 are telescopically assembled and seal 18 is made, the annular space 21 between the -4 tubes is pumped to a hard vacuum, of the order of 10 torr or less. The assembly 17, 18, 15, 20 is baked at high temperature for removal of moisture. The tabulation 16 at the end of the cover tube 15 is tipped off (sealed) in the known manner, so as to form a vacuum tight seal.

The manifold 11 is shown in detail in Figs. 3 to 11. Referring first to Figs. 3 to 5 and 7, a series of cups 22 are made as metal stampings, such - 8 as copper (selected for corrosion resistance). Cups 22 have an annular, outwardly flared and stepped wall 23 which provides a flange 24 at the outer open end thereof and an end wall 25 across the opposite closed end. Interiorly of flange 24 is an annular groove 26, which provides a gasket seat for a silicone rubber 0-ring gasket 27 (Fig. 7).

As seen in Fig. 4, the cups 22 are arranged in coaxial, oppositely facing pairs, indicated 22 and 22', such that the interior closed end walls 25 of each are in abutting relationship. An aperture 28 is punched in each closed end wall 25 and a metal tab portion of one end wall is folded or bent over the periphery of the aperture 28 in the other abutting end wall 25 and crimped. The pair of cups 22, 22', in each instance, together define a rim 29 at aperture 28 which receives a later assembled circular grommet 30, preferably comprised of silicone rubber. Along wall 23 of the cups, a circular port 31 is out in each stamping to receive the ends of a copper tube 32, which serves as a liquid cross connection between a oup 22 and another cup 22'. The cups 22, 22' and cross connecting tubes 32 are placed with their longitudinal axes in a common plane and with the pairs of members 22, 22' disposed in laterally spaced apart, mutually parallel relation, as shown in Figs. 4 and 5, ready for fastening them in an assembly.

Along the sides of the assembly of cups 22, 22', as best seen in Fig. 4, there are provided two copper header tubes, the one being used as inlet header tube 33, positioned along one side of the cups and disposed between the opposite facing flanges 24 thereof, and 438 SS - 9 the other tube being used as outlet header tube 34 and similarly positioned along the other side of the cups. The headers 33, 34 extend in parallel, generally, with the longitudinal dimension of the manifold assembly which coincides with the cross-over tubes 32. Inlet header 33 has a stub pipe 36 (Figs. 3 and 5) connecting it with the interior of the one end cup 22 of the manifold series, the pipe 36 being fastened into another port formed in the wall 23 of the end cup 22 at about 90 degrees from the cross-over pipe connection point, inis connection via pipe 36 serves to introduce fluid into the first cup pair of the series in the manifold section. Fluid is removed from the manifold through a port in the wall 23 of the last cup 22 of the series, which is connected by stub pipe 38 into the outlet header tube 34.

The header tubes may be arranged, as shown on Fig. 5, so that the manifold sections may be connected one to another in series. The inlet header 33, for example, will be sweat solder connected with an outlet header 34' (in phantom outline on Fig. 5) from a preceding manifold section at the flanged end 33a, the opposite end 33b being closed. The outlet pipe 34 is reversed in that the flanged end 34a is disposed opposite the closed end 33b of the inlet header, and closed end 34b is opposite flanged end 33a. Outlet header 34 will in turn receive at its flanged end 34a the end of the next inlet header pipe 33' (Fig. 5) and the two sweat soldered together. The inter-modular connections, just described, will be made at the job site in erecting the particular modular configuration called for by the installation of the system. 43853 - 10 The parts are assembled as above described in a fixture and furnace brazed into a unit in a known manner. After the parts are assembled and brazed together for a manifold section, the unit is placed into a mold for defining a thermal insulation jacket, shown in particular in Figs. 6 to 9, The jacket 39 is molded, preferably by a foam-in-place process, whereupon the assembled metal manifold parts, just described, are thermally insulated with a low density cellular insulation, such as foamed polyurethane. The polyurethane material is preferred for its excellent thermal insulation properties and its hard skin covering. The mold (not shown) provides the exterior contours of the insulation jacket 39 shown on the drawings and particulate polyurethane and foaming agent are added to fill the mold. As is shown on Fig. 6, the foamed plastic insulation jacket 39 is shaped generally as a cylinder, the inlet header tube 33 or both inlet and outlet header tubes 33 and 34 (as on Fig. 6) protruding from the longitudinal end of the manifold section 11. The mold in which the insulation jacket 39 is formed includes plugs and cores to form the apertures 40 for inserting the open end of the tubular collectors therein and in sealing connection with the 0-ring gasket 27 held by the annular groove 26 provided at flange 24 of the cups 22 (Fig. 7).

The insulation is molded with flat faces 41 for butting the end of the cover tubes thereon in seating the collectors into the socket-like connections, i.e. gasket 27 in the flange end of cup 22.

The final molded insulation jacket is next coated with a thin layer of corrosion resistant material, sealing the exposed outer cells or pores of the £3888 insulation. This sealant may take the form of a white paint material, and an example of a preferred sealant material is a brushed or sprayed on layer of an organopolysiloxane resin dissolved in n-butanol solvent, the mixture of resin and solvent containing about 40% by weight of roair. solids. The applied layer ie dried and cured to provide a protective coating over the outer hard skin of the insulation exhibiting good wear resistance.

There are shown in the drawings the two different configurations of manifold sections needed for connecting the modules in series in an elongate bank thereof; these being the end sections of manifold for placement at either end of the system, and the intermediate sections joined together therebetween.

The end section of manifold is shown on Fig. 9, which indicates an initial inlet connection Of the system working fluid which is connected at an elbow 42 sweat soldered onto inlet header 33. The inlet supply pipe of the heating/cooling system is connected at the elbow 42. After the connection is made, the exposed piping is covered by an end cap 43 which fits over the end of the insulation jacket 39 and an arcuate recess 44 on either side of the cap 43 fits around the cover tube of a tubular collector 10 installed in the end aperture 40 nearest the cap.

An intermediate section of manifold is shown on Figs. 6 and 8. In this instance, the foamed thermoplastic insulation jacket 39 is formed the same way as described above, and the two header pipes 33 and 34 protrude from each axial end of the section. The intermediate sections are placed 180° from each other such that an inlet header tube 33 of the next section is connected to the outlet header tube 34 of the previous section, reference being left to right in Fig. 8. Similarly, the outlet header tube 34 is connected to an inlet header tube 33 of the previous section, the pipes and flanges are interfitted and sweat soldered together to make a fluid tight coupling of the sections. Next, a split coupling collar 45 is assembled over the adjacent ends of the two connected manifold sections and fastened in place.

The split collar 45 has a semi-circular, annular web 46 that includes two arcuate recesses 44 formed opposite the tubular collectors to be inserted into the apertures 40 at the adjacent end positions on the manifold. The split sections of collar 45 have a radial, arcuate centre rib 47 for engaging the end face of the insulation jacket 39 of the two coupled together sections of manifold. In essence, the split coupling collar 45 of the insulation material is like a special split washer. The collar halves 45 are assembled together in full arcuate array encircling the adjacent ends of the manifold jacket sections and fastened together in place by suitable means, such as an adhesive or by tape.

At the last section of manifold selected in the system design, an end section similar to that shown in Fig. 9 is used but shifted through 180° so as to provide the outlet pipe connection for the fluid into the heating/cooling system.

One means Of mounting the manifold sections on the installation's supporting structure is by the support bracket elements 13 shown on Figs. 1, 10 - 13 and 11, with occasional references also to Fig. 9.

An angle bracket 48 is cast in a lower support segment 49 formed integrally with the end section of the insulation jacket 39, shown on Fig. 9. This bracket 48 is placed beside a corresponding L-shaped lower bracket 50 and fastened thereto securely by studs 51. Prior to this, the lower bracket 50 may be fastened in place on the surface 12 of the roof structure over a rubber gasket 53, screws 54 and lock washers 55.

The support elements 13 space the sections of the manifold 11 above the surface 12 to fulfil Lhe purposes Of: (1) supporting the manifold and in turn the tubular collectors 10 at their one end and a prescribed distance above the diffuse-reflector surface 12 for optimum operation, and (2) supporting the manifold itself above the roof surface to allow water, ice and snow to drain on the roof surface, if such be the place of the installation. Also, in this latter connection, wind is allowed to travel around the manifold, which is designed in the contour of the manifold (cylindrical shown herein) for best air flow and least wind resistance.

Having described manifold 11 and its relationship to the tubular collectors 10 in supporting them at their one end 17b, the other closed end 17a is supported in members 14 secured to the surface 12 and extending parallel with the longitudinal axis of manifold 11. The detail of the tube end support member 14 is shown in Figs. 12 to 14. The member 14 is formed of metal and stamped to an L-shaped configuration. The lower or base leg 56 of the member is provided along the free edge surface with 4385S an outer scalloped edge 57 sinusoidally contoured (as a sine wave) enabling flush end-to-end assembly of two modules of the collector, as shown on Fig. 1. The leg 56 also includes slots 58 in the metal which terminate in drain holes 59 which serve as a means for draining water along a roof where the solar collectors are installed. The upstanding leg 60 of member 14 is formed with contoured apertures 61 spaced therealong to correspond with.the spacing of the tubular collectors 10 along the manifold. The centres of the respective apertures should align with the axis of the cups 22 in the manifold. On the periphery of apertures 61 are a plurality of lugs 63. A frusto-conical end cap 62, formed of plastics material, is placed over the tubulation 16 at closed end 17a of a collector tube 10 that is inserted through aperture 61.

Prior to assembling the tubular collector on the end bracket 14, a longitudinal feeder tube 73 (Fig. 2) is inserted through the rubber grommet 30 retained in the aperture in the end wall 25 of the manifold cups. Feeder tube 73 is preferably made of glass and extends through grommet 30 so that one end of tube 73 is near the closed end 17a of the absorber tube 17 of the tubular collector on the right hand side of the manifold and the other end of this tube 73 extends to near the closed end 17a, of.the absorber tube in the collector that is assembled on the left hand side of the manifold (Fig. 7). Thus, the feeder tube will be in position in the manifold grommet opening before the tubular collector elements comprised of tubes 15 and 17 are placed into the manifold seat at the O-ring gasket 27 thereof. Of course, the depending feeder 3 3 5 5 tube ends are inserted inside the absorber tube at this time in assembly. Thereafter, the closed end of the collector is placed through the aperture 61 in the end support structure 14.

Next, an end retainer member 64 is fitted over tubulation 16 with a coil spring 65 compressed therebetween, the inner end of the member 64 fitting over an annular end boss 66 on cap 62. The opposite end of the coil spring 65 is compressed against the inner surface of end wall 67 of the retainer 64. A vent 68 is provided in wall 67 for the draining of rain water. With the closed end 17a, of the collector tube carrying end cap 62, spring 65 and retainer member 64, the retainer housing is pushed axially toward the aperture compressing spring 65. The glass engages spaced apart axially disposed interior webs or ribs 72 of the end cap 62. Lugs 63 are aligned with notches 69 in a rear flange 70 of the retaining member, the notches corresponding in spacing annularly with lugs 63 about the inside periphery of aperture 61. By axial pressure on assembly, lugs 63 pass through notches 69, whereupon the retainer is twisted clockwise (Fig. 14) and released. The flange 70 and lugs 63 co-operate as a bayonet-type fastener for connecting the retainer member to the end support bracket through the aperture 61. Twisting movement in that direction is restrained when the lugs 63 butt against the longitudinal wall 71 spaced about the periphery of the retainer 64. When the pressure is released after twisting, the compression force of spring 65 drives the retainer assembly forward and locks the flanges 70 against the lugs 63. This is a form of a bayonet, twist lock. Thereafter, the 43888 outer glass tube,of the tubular collector 10 rests solely in the plastic end cap 62 avoiding scratching of the glass surface and the tubular collector 10 is axially loaded and seated on its 0-ring gasket 27 in the mouth of the cup 22 of the manifold, in the position shown in Fig. 7.

The end force applied by the collectors 10 may be established for low pressure operation. At pressures internally exceeding 10 psig, the collector tubes 10 .0 will be lifted from the 0-ring seat with the internal pressure acting on the absorber tube cross sectional area at the closed end 17a biased only by the axial spring load in the end cap assembly. Thus, glass failure will be avoided by leakage or bleed off of the working fluid which will relieve excess pressure build up to protect the glass parts.

Fig. 15 illustrates a system in diagrammatic form which may utilize the aforegoing apparatus. The heated fluid flows from the outlet header pipe 34 into a ) heat storage sump 74 that is vented at 75 through a relief valve 76. The hot fluid is connected by a pipe 77 to the inlet of a low pressure pump 78 which maintains circulation of the fluid through a heat exchanger 79 that is connected to a load. Fluid transferred through the heat exchanger device 79 is connected to the inlet header pipe 33 to complete the circuit. The closed circuit is maintained at the relatively low pressure selected for the system.

It should be understood that several other systems could be connected into the solar energy collector device of the invention, the foregoing installation, illustrated schematically on Fig. 15, is given merely - 17 by way of an operating example.

When a plurality of manifold sections of cylindrical configurations are joined together, the individual sections preferably have the same diameter.

Attention is hereby directed to Patent Specification No. 43854 which describes and claims a solar energy collector module comprising a plurality of tubular collector elements having the same outside diameter and each including a circumferentially transparent outer tube having a closed end and an open end, interiorly of said outer tune, a noiiow elongate absorber member spaced from said outer tube, having a closed end and an open end extending outwardly of the open end of the outer tube, and including a solar energy absorbing surface disposed between its ends, means sealing the open end of the outer tube around the absorber member to provide a closed space between the two, said space being evacuated to sub-atmospheric pressure, the absorber member having an interior chamber, an elongate manifold having lateral, outwardly facing cups for receiving the open ends of said absorber members, each said cup comprising an annular flange at its outer open end, an 0-ring gasket, and annular retaining means in said flange for holding said gasket, the gasket forming a fluid seal in the cup encircling said absorber member, an inlet header pipe adapted to be connected to a fluid supply and to at least one of said cups, means interconnecting the cups for flow of fluid through the absorber members and between the cups, an outlet header pipe connected to at least one of said cups for receiving fluid therefrom, and a thermal insulation jacket member of low density cellular material surrounding all of said cups, the interconnecting means therefor and said inlet and outlet header pipes, said jacket including apertures coaxial with said cups for connecting the 5 tubular collector elements into said cups of the manifold, and means supporting the tubular collector elements sealingly in said cups of the manifold.

Our latter pending Application also claims a solar energy collector apparatus which includes such a module.

Claims (9)

1. CLAIMS:1. An elongate manifold for a solar energy collec tor comprising a plurality of pairs of metal cup-shaped members whose open mouths are eaah defined by annular flange portions and which are disposed with the two cup-shaped members in each pair coaxial and back-to-back so as to define two compartments, respectively, which are separated by a transverse partition formed by their bases, the pairs of cup-shaped members being disposed in laterally spaced apart, mutually parallel relation longitudinally of the manifold, with the longitudinal axes of the cup-shaped members all lying in a common plane, an inlet header pipe extending longitudinally of the manifold, a first fluid handling conduit connecting the inlet header pipe to at least one of said compartments formed by said plurality of cup-shaped members, an outlet header pipe extending longitudinally of the manifold and spaced from the inlet header pipe, a second fluid handling conduit connecting at least one other of said compartments formed by said plurality of cup-shaped members to the outlet header pipe, means interconnecting the compartments of the cup-shaped members to enable fluid flow therebetween, and a thermally insulating jacket member comprised of a cellular insulating material and surrounding the cup-shaped members, the inlet and outlet header pipes and the fluid handling conduits, the jacket member including apertures providing access to the flanged openings of said cup-shaped members for connecting solar collector apparatus externally of the jacket member to the cupshaped members. - 20

2. A manifold apparatus as claimed in claim 1, wherein the outlet header pipe and inlet header pipe each extends beyond the opposite longitudinal ends of the insulating jacket member.

3. A manifold apparatus as claimed in claim 2, having a plurality of manifold sections interconnected end-to-end at the outlet header pipes, and inlet header pipes respectively for flow of fluid throughout said plurality of manifold sections.

4. A manifold apparatus as claimed in claim 3, wherein the plurality of manifold section·’ are of substantially cylindrical configuration of substantially the same diameter.

5. A manifold apparatus as claimed in claim 4, wherein the end-to-end assenibled manifold sections are longitudinally spaced apart, and in which is included a split cylindrical collar member encircling the interconnected inlet header and outlet header pipes in the space between each of the adjacent manifold sections of. the interconnected plurality thereof, the said collar member being comprised of a cellular thermally insulating material and being in abutting end engagement with the ends of the thermally insulating jacket component of said manifold sections.

6. A manifold apparatus as claimed in claim 5, wherein the opposite endmost manifold sections of the plural section manifold each include a cylindrical end cap, each of which is comprised of cellular thermally insulating material enclosing the outwardly extending portion of the outlet and inlet header pipes thereat.

7. A manifold apparatus claimed in claim 6, wherein the cellular thermally insulating material of the cylindrical insulating jacket members, each split cylindrical collar member and opposite cylindrical end caps are comprised of a foamed polyurethane material. 5

8. A manifold apparatus as claimed in claim 1, wherein a plurality of mounting brackets are fastened to the insulating jacket member of each of said manifold sections and depend therefrom normal to the axes of the cup members of the manifold sufficiently 10 for spacing the insulating jacket member thereof from a supporting surface.

9. A manifold apparatus for a solar energy collector substantially as hereinbefore particularly described with reference to and as illustrated in 15 the accompanying drawings.