Energy conversion apparatus

A modular solar collector comprises a plurality of detachably interconnected modules forming a closed structural surface. Each module comprises a solar collector unit with a cavity receiving a heat carrier fluid through an inlet and delivering the heated fluid through an outlet, the inlet and out each having a coupling part. The unit is carried on a mounting plate which has a conduit portion for the fluid embedded therein. The inlet and outlet ends of the conduit portion each has a coupling part. The inlet end coupling part and the outlet coupling part, on the one hand, and the outlet end coupling part and the inlet coupling part, on the other hand, are matched for detachable assembly to form detachable joints between respective registering pairs of the coupling parts for detachably assembling the unit and the mounting plate. One of the detachable joints detachably assembles adjacent ones of the mounting elements and the conduit portions detachably joined to the cavities form a conduit system for the heat carrier fluid to and from the cavities. The unit comprises a transparent front plate, a rear plate, the plates defining the cavity therebetween, and an element arranged between the outer surface of the front plate and the inner surface of the rear plate which does not transmit solar radiation.

The present invention relates to improvements in energy conversion 
apparatus for converting solar into thermal energy. Such apparatus 
comprises modules of an energy conversion unit arranged for exposure to 
solar radiation and defining a cavity capable of receiving a heat carrier 
fluid, the unit including an inlet and an outlet for the fluid in 
communication with the cavity, and a mounting element carrying the energy 
conversion unit. A conduit delivers the heat carrier fluid, such as water 
or air, to the cavities and removes the heated fluid therefrom to a heat 
consumption system normally including a heat exchanger. 
It is one primary object of this invention ro provide a modular energy 
conversion apparatus of this general type wherein the construction of a 
moisture-proof and preferably heat-insulating closed structural surface is 
facilitated, which may find use, for example, as a roof covering without 
requiring any additional structural elements. 
It is a further object of the invention to minimize heat losses in the 
inlet and outlet conduits of the heat conversion units of such an 
apparatus. 
It is another important object of the present invention to provide a closed 
modular structural surface, such as a roof covering or a wall, which is 
comprised of such detachably assembled modules on which the heat 
conversion units are detachably mounted and can be removed from their 
mounting elements without destroying the closed surface. 
The above and other objects are accomplished in accordance with one aspect 
of the invention with a modular energy conversion apparatus for converting 
solar into thermal energy, which comprises a plurality of interconnected 
modules each module comprising an energy conversion unit and a mounting 
element carrying the unit. The energy conversion unit is arranged for 
exposure to solar radiation and defines a cavity capable of receiving a 
heat carrier fluid, the unit including an inlet and an outlet for the 
fluid in communication with the cavity, and the inlet and the outlet each 
having a coupling part. The mounting element includesa conduit portion 
embedded therein and having an inlet and an outlet end, the inlet and 
outlet ends of the conduit portion each having a coupling part. The inlet 
end coupling part and the outlet coupling part, on the one hand, and the 
outlet end coupling part and the inlet coupling part, on the other hand, 
are matched for detachable assembly to form detachable joints between 
respectively registering pairs of the coupling parts for detachably 
assembling the energy conversion unit and the mounting element. One of the 
detachable joints detachably assembles adjacent ones of the mounting 
elements, registering ones of the coupling parts forming the one 
detachable joint, and the conduit portions detachably joined to the 
cavities form a conduit system for the heat carrier fluid to and from the 
cavities. 
In the closed modular structural surface constituting another aspect of 
this invention, each of the detachably interconnected modules forming the 
surface comprises an energy conversion unit arranged for exposure to solar 
radiation and defining a cavity capable of receiving a heat carrier fluid, 
and a mounting element carrying the unit and including a conduit portion 
embedded therein. The conduit portions join the cavities to form a conduit 
system for the heat carrier fluid to and from the cavities, and adjacent 
mounting elements are connected to form the closed surface. 
Separating the energy conversion module into an energy conversion unit and 
a mounting element therefor makes it possible to vary the structures of 
the unit and/or element widely so that they may be adapted to special 
needs. Thus, the mounting elements may be adapted to various existing roof 
structures, thus making it possible to replace desired portions of such 
structures with the energy conversion aparatus of this invention. Complex 
support elements may be eliminated since the mounting elements themselves 
may be adapted for direct support on existing roof frames. The detachably 
mounted energy conversion units may be readily removed for repair, 
servicing or replacement. The manufacture of all parts and their assembly 
is simple and, therefore economical. The conduit system for the heat 
carrier fluid, which usually must be connected on-site by specially 
constructed inlet and outlet conduits is built into the mounting elements, 
thus being completed simply by assembling the same. The detachable conduit 
joints may readily be made fluid-tight and heat-insulated to avoid heat 
losses, and damage to the energy conversion units is avoided during 
assembly of the closed structural surface since the units may be mounted 
on the mounting elements after the same have been assembled. 
In the closed modular structural surface of the present invention, the 
mounting elements are detachably inter-connected by complementary coupling 
parts of conduit portions forming the conduit system for the heat carrier 
fluid. The coupling parts preferably extend perpendicularly from the 
mounting elements, the fluid being preferably supplied through an inlet 
coupling part from below and being removed through an outlet coupling part 
from above, thus providing a thermal fluid movement component in addition 
to pressure applied by a pump supplying the fluid to the apparatus. 
Modules extending in horizontal rows may be interconnected in series while 
the modules in vertical rows are connected in parallel.

Referring now to the drawing and first to FIG. 1, there is shown an energy 
conversion apparatus 1 for converting solar into thermal energy. This 
apparatus is comprised of a series of energy conversion units 2 each 
consisting of a solar radiation collector and of associated mounting 
elements 3. Each mounting element receives an associated energy conversion 
unit and, in the illustrated embodiment, is an essentially plate-shaped 
body. At least the upper surface of this body, and in the illustrated 
embodiment the entire body, is of a moisture-impervious and thermally 
insulating material. A rigid synthetic resin, preferably a plastic foam, 
is a very useful material for the mounting elements. Mounting elements of 
such material can serve as roof coverings if the apparatus is disposed on 
a roof and may thus save roof tiles or other roof coverings. 
Conduit system 5, through which a heat carrier fluid is passed, comprises 
conduit portions 4 each embedded in a respective one mounting elements 3. 
The mounting elements with their embedded conduit portion may be mass 
produced simply in suitable molds wherein a suitable synthetic resin is 
molded and foamed about conduit portions 4 inserted in the mold. 
Each plate-shaped mounting element 3 has an abutment 7 projecting 
downwardly from the lower surface of the element at one end of the element 
and a shoulder 10 projecting laterally from the upper surface of the 
element at an opposite end thereof. Such mounting elements may be 
assembled in series on a roof structure 6, as shown in FIG. 1, to form a 
roof covering which is impervious to moisture and may thus serve as an 
effective roof covering with or without mounting energy conversion units 
thereon. In this manner, all types of energy conversion units may be used 
without further taking into consideration the need for moisture-proofing 
the roof. As illustrated, roof structure 6 comprises rafters 9 and roof 
battens 8, and each mounting element 3 is suspended at one end on a 
respective batten 8 engaged by abutment 7 and supporting the lower surface 
of theelement, and at the opposite end on the upper surface of an adjacent 
mounting element engaged by shoulder 10, the shoulder defining a recess in 
the mounting element into which the adjacent mounting element fits. Thus, 
the shoulder 10 of each mounting element 3 over-laps an adjacent end of an 
underlying mounting element. The shoulders define grooves facing the upper 
surfaces of the underlying mounting elements which grooves serve as water 
conduits for removing water from the roof structure covering. 
Each conduit portion 4 has respective coupling parts 11, 12 at the ends 
thereof, the coupling parts extending perpendicularly to the upper surface 
of the mounting element wherein the conduit portion is embedded. The 
conduit portion of each mounting element extends from coupling part 12 in 
the region of the one end of the mounting element towards the opposite end 
thereof. The shoulder of each mounting element defines a bore 14 extending 
perpendicularly to the upper surface of the mounting element for receiving 
coupling part 12 of an adjacent mounting element, coupling part 12 
projecting from the upper surface of the adjacent mounting element into 
bore 14 which is in registry therewith. 
The illustrated energy conversion units 2 are comprised in the illustrated 
embodiment of rear wall 17, preferably also made of a rigid synthetic 
resin, and a transparent front wall 19, which may be a double-walled glass 
or synthetic resin plate. Such double-walled plates provide increased heat 
insulation and reduce radiation losses of the heat carrier to the ambient 
atmosphere. The walls of the unit 2 define therebetween a cavity 18 which 
may be constituted by a meandering channel system 18, the cross sections 
of the channels being substantially parabola-shaped and the focal length 
of the parabola being relatively short. A heat carrier fluid supplied 
through conduit system 5 passes through the meandering channel system 18 
and solar radiation energy impinging upon transparent front wall 19 and 
absorbed by an underlying absorption plate heats the carrier fluid passing 
through the channel system, thus converting solar into heat energy. Thus, 
the temperature of the heat carrier fluid increases as it flows from one 
energy conversion unit to the next. The cavities 18 of units 2 are 
connected in series to conduit system 5, respective ends of each cavity 
having coupling parts 15, 16 arranged to form fluid-tight joints 13 with 
coupling parts 12, 11 of associated conduit portions 4, coupling parts 15, 
16 also extending perpendicularly to the support surfaces of mounting 
elements 3. As shown in FIG. 1, coupling part 15 forms the inlet and 
coupling part 16 the outlet for each cavity 18. When solar collector 2 is 
placed on the upper surface of a mounting element 2 with coupling part 15 
in registry with bore 14 and projecting thereinto and coupling part 16 in 
registry with coupling part 11 and projecting thereinto, coupling part 12 
projects into coupling part 16 and the registering coupling parts form 
telescoping joints 13 wherein coupling parts 11 and 15 constitute sockets 
receiving coupling parts 16 and 12, respectively. O-rings 20 are 
interposed between the telescoping coupling parts to form fluid-tight 
joints 13 as the solar collector 2 is pressed upon the underlying mounting 
element into flush engagement with the upper surface thereof. If desired 
and preferably, any leaks may be prevented by using a silicon paste or 
like putty in spaces remaining along adjoining edges of units 2 and 
mounting elements 3 to provide air-tight joints and thus to make best use 
of the heat insulating property of mounting elements 3 for insulating the 
rear wall of the solar collectors. In this manner, the simple step of 
pressing the solar collectors against the mounting elements will not only 
couple together all the cavities of the solar collectors in series but 
joint 13 in bore 14 will also connect the adjoining mounting elements to 
each other. This will greatly facilitate the assembly and save costs, 
reducing the number of couplings and joints to a minimum. 
If the heat-insulating material of mounting element 3 wherein conduit 
portion 4 is embedded is light-transparent in the direction of solar 
collector 2 while it is light-absorbing in the opposite direction, the 
heat insulation of the embedding material will not only reduce heat losses 
in the heat carrier fluid passing through the conduit portion but this 
conduit portion may actually serve for obtaining additional heat energy. 
As is apparent from FIG. 1, the joined series of mounting elements 3 and 
their associated energy conversion units 2 form a detachable modular 
covering for a structure, which may be readily assembled and disassembled, 
the mounting elements constituting a closed surface for the structure and 
incorporating portions of a conduit system through which the heat carrier 
fluid passes. 
FIGS. 2 and 3 illustrate modified embodiments of a mounting element 21 and 
an associated energy conversion unit 22, respectively. Mounting element 
21, as illustrated in FIG. 2, has mounting and guide device 23 on the 
upper surface thereof for slidably guiding and mounting unit 22 thereon. 
The mounting element of this embodiment is a plate-shaped body similar to 
a roof tile and thus makes it possible to replace an existing roof 
covering readily with an energy conversion apparatus using mounting 
elements 21 for receiving energy convention units. The heat carrier fluid 
conduit system 5 of the embodiment shown in FIG. 2 comprises inlet conduit 
portion 24 and outlet conduit portion 25 embedded in mounting element 21, 
the inlet conduit portion 24 having coupling parts 26 and 30 at the ends 
thereof while outlet conduit portion 25 has respective end coupling parts 
27 and 31. Coupling parts 26 and 27 extend through mounting and guide 
device or molding 23 and, when mounting element 21 and energy conversion 
unit 22 are assembled by means of molding 23, coupling parts 28 and 29 in 
communication with meandering channel system 32 in unit 22 are in registry 
with coupling parts 26 and 27, the telescoping coupling parts forming 
joints 13. Coupling parts 30 and 31 extend perpendicularly to the opposing 
surfaces of mounting element 21. When two adjacent mounting elements are 
connected to form a series of mounting elements in the manner of the 
assembly of FIG. 1, projecting coupling part 31 of one mounting element 
will be in registry with coupling part 30 of an adjacent and overlying 
mounting element, coupling part 31 telescopingly engaging coupling part 
30, somewhat in the manner of coupling parts 12 and 15 of FIG. 1. While 
coupling parts 26 and 27 extend substantially parallel to the major 
surfaces of mounting element 21, coupling parts 30 and 31 extend 
perpendicularly thereto. The mounting elements are assembled with their 
associated energy conversion units simply by sliding each unit 22 along 
the upper surface of an associated element 21 into the open end of molding 
23, and the superposed and overlapping arrangement of the tile-like 
elements 21 will provide a closed roof covering while conduit system 21 
will interconnect cavities 18 in the energy conversion units in series in 
a manner equivalent to that described in connection with FIG. 1. Molding 
23 enables the mounting elements 21 and energy conversion units 22 to be 
plugged together, units 22 being shaped and dimensioned to fit into 
molding 23. 
By arranging the coupling parts of the inlet as well as the outlet conduits 
in the mounting element and the energy conversion unit, respectively, in 
registry, when assembled, the simple assembly of the mounting element and 
the energy conversion unit will provide a module in which the heat carrier 
fluid conduit system is fully connected. In this arrangement, inlet 
conduit coupling part 28 and outlet conduit coupling part 29 of energy 
conversion unit 22 are parallel to each other and extend perpendicularly 
to transverse edges 33 and 34 of the unit whence they project. While three 
edges of the unit, i.e. transverse edge 34 and longitudinal edges 35 and 
36, are grooved guide elements fitting three-sided molding 23, which 
enables unit 22 to be snapped onto mounting element 21, the fourth edge, 
i.e. transverse edge 33, fits the open side of molding 23 and holds inlet 
conduit coupling part 28. Transverse edge 33 has bores 37 for receiving 
fastening elements, such as screws or bolts, for fastening unit 22 on 
mounting element 21, aligned bores being provided in the two ends of 
molding 23 to receive the fastening elements. 
With the tile-like mounting elements 21, it is possible first to cover an 
entire roof by assembling the elements in overlapping relationship, rows 
of such elements being interlocked by telescoping joints formed by the 
coupling part 31 of one element projecting into coupling part 30 of an 
adjoining overlying element, while the longitudinal rims of the elements 
of one row overlap and engage the longitudinal rims of the elements in the 
adjacent row. In this manner, a closed roof covering is produced and 
energy conversion units 22 may then be simply mounted on the mounting 
elements by pressing them onto moldings 23 serving as mounting and guide 
devices for units 22, this mounting automatically interconnecting the 
coupling parts in the mounting elements and the energy conversion units to 
complete the conduit system for the heat carrier fluid. Units 22 are 
securely maintained in position by driving fasteners into bores 37. If 
desired, edges 34 to 36 and/or molding 23 may be grooved to permit 
application of putty or like sealant to provide good moisture insulation 
between mounting elements 21 and energy conversion units 22. 
FIG. 4 illustrates a specific embodiment of a joint between the coupling 
parts of the mounting element and the energy conversion unit. Applied to 
outlet coupling part 29 of unit 22 and coupling part 27 of mounting 
element 21 of FIGS. 2 and 3, this enlarged sectional view of the joint 
shows the coupling part 29 to include tubular part 38 projecting 
perpendicularly from transverse edge 34 of unit 22 while the coupling part 
27 embedded in mounting element 21 is a sleeve 39 arranged to receive 
tubular part 38. A fluid-tight joing is assured by arranging O-rings 39 in 
grooves in sleeve 39 for gripping the tubular part inserted therein 
telescopingly when unit 22 is slid or plugged into the mounting element. 
The simple assembly of mounting element and energy conversion unit with 
registering coupling parts makes it possible to provide exchangeable 
elements and easy mounting. The telescoping joints, particularly when 
provided with O-rings or similar gaskets, provide fluid-tight connections 
which may be rapidly coupled and uncoupled. Using O-rings is very 
inexpensive and provides tight joints at elevated temperatures. 
FIG. 5 shows a modification of the joint of FIG. 4, also applied to 
coupling parts 27 and 29 but obviously applicable to any joints 13 between 
the telescoping coupling part connections herein described. In this 
embodiment, coupling part 29 of energy conversion unit 22 comprises 
projecting tubular part 42 defining circumferentially extending, annular 
groove 41. Coupling part 27 embedded in mounting element 21 comprises 
sleeve 43 for telescopingly receiving tubular part 42. Fixing device 44 is 
mounted on sleeve 43 and is arranged to hold tubular part 42 in position 
when it is inserted in sleeve 43 but to permit ready uncoupling and 
withdrawal of part 42 from sleeve 43. The illustrated fixing device 
comprises a bush mounted on sleeve 43 and radially yieldably holding 
locking balls 46. The locking balls are snapped through apertures in 
sleeve 43 into groove 41 when tubular part 42 is telescoped into sleeve 43 
but permit ready withdrawal of part 42 from sleeve 43. This may be readily 
accomplished by providing slot 47 in mounting element 21, insertion of an 
operating wedge 48 into slot 47 in a direction perpendicular to joint 13 
pressing unit 22 away from coupling part 27, radial movement of balls 46 
out of groove 41 uncoupling the joint. This arrangement will assure that 
the joint will remain securely in position even under adverse ambient 
conditions, such as strong winds or pressure of snow laying on the roof, 
while permitting ready uncoupling for repair work, for example. 
To prevent heat carrier fluid from escaping from conduit 25 in mounting 
element 21 when energy conversion unit 22 is detached, coupling part 27 
has mounted therein a spring-biased check valve 45 which will be moved 
into closing position by its spring when tubular part 42 is withdrawn from 
sleeve 43. 
FIG. 6 illustrates an embodiment of an energy conversion apparatus 
particularly useful in new buildings which have no existing roof covering. 
For purposes of illustration, two assembled modules are shown, each 
comprising a mounting element 56 of relatively large surface area on which 
a plurality of energy conversion units 62 are mounted. Side edges 57 and 
58 of mounting element 56 have dove-tailed or projecting guides 59 for 
connection with meshing guides on the side edges of adjoining mounting 
elements for assembly into a closed roof covering. Any spaces between the 
adjoining edges of the mounting elements are preferably filled with 
silicone paste or any other suitable sealant to provide a fluid-tight and 
thermally insulated roof. 
Heat carrier fluid conduit portions 60 forming conduit system 61 are 
embedded in the mounting element to enable a plurality of energy 
conversion units 62 to be assembled thereon, the conduit joints being 
formed with coupling parts 66 of conduit portions 60 in the manner 
hereinabove described. Any of the units 62 may be detached from the 
mounting element for repair when such joints are used, as has been 
described. 
It is also possible to provide end members 63 for assembly with sides edges 
58 of mounting element 56, member 64 being through-shaped to serve as a 
gutter and member 65 being shaped to serve as coping for the roof. The 
coupling parts 67 and 68 leading from conduit system 61 extend 
perpendicularly to side edges 57 of the mounting element in opposite 
directions and at opposite ends, enabling them to be brought into registry 
with coupling parts in adjoining mounting elements when the roof covering 
is assembled. 
As shown, pressure relief valve 69 under a thermostat control 70 may be 
arranged in conduit system 61 so as to avoid overheating of mounting 
elements 56 and control of the heat carrier fluid flow generally when the 
energy conversion units are assembled and detached. Additional valves may 
be built into the conduit system to provide desired fluid flow control. 
FIG. 7 shows another embodiment of a mounting element. The mounting element 
49 is comprised of corrugated asbestos shingle 50 forming a roof covering 
and carrying synthetic resin body 53 which preferably is a multi-layered 
plastic foam body mounted on the asbestos shingle. Depending on 
circumstances, the mounting element may be pre-fabricated by foaming 
multi-layered body 53 on the asbestos shingles or body 53 may be bonded to 
existing corrugated asbestos shingles on a roof with the use of suitable 
adhesive agents. The illustrated synthetic resin body 53 is a laminated 
body consisting, for instance, of a polyurethane foam layer 55 and a 
surface layer 54 of glass fiber reinforced synthetic resin. 
Such multi-layered synthetic resin bodies have enhanced thermal insulating 
properties which provide very effective insulation and desired rigidity 
even when relatively thin. 
FIG. 8 illustrates a saddle roof whose one side 71 has a conventional 
covering, for instance of roof tiles or shingles, while the other side is 
formed by two horizontal rows 72, 73 of energy conversion modules of the 
type described in connection with FIG. 6, like reference numerals 
designating like parts functioning in an equivalent manner. Coping members 
65 are attached to the upper edges of the mounting elements of upper row 
72 while gutter members 64 are attached to the lower edges of the mounting 
elements of lower row 73. End elements 74 and 75 are connected to the 
mounting elements of the modules, the elements being substantially like 
elements 56 but narrower and not adapted to carry energy conversion units. 
The have embedded therein bridging conduits 76 and 77 with coupling parts 
66, 67 enabling the conduit systems 61 of two adjoining horizontal rows of 
modules to be connected in series. The connection of the mounting elements 
along butt joint 78 between the horizontal rows of mounting elements is 
effected in the same manner as along edges 57 and 58, i.e. by means of 
dove-tailed or projecting guides. A portion of bridging conduit 77 is 
embedded in the upper end element 75 while another portion thereof is 
embedded in the lower end element 75, the portions being aligned and 
joined by coupling parts 66, 67. The lower end element 75 has an inlet 
conduit 80 for delivering a heat carrier fluid to the energy conversion 
apparatus, the upper end element 75 having an outlet conduit 81 for the 
fluid. 
FIGS. 9 and 10 show a wall 83 composed of assembled wall elements or plates 
82, each wall plate having an outer surface carrying two rows of two 
energy conversion units 84 each. These units are detachably mounted on the 
surface of the wall plates in a manner hereinabove described, the conduit 
portions 85 and 86 being embedded in the wall plates near the respective 
abutting edges of the wall plates, the conduit portions having coupling 
parts 89, 90 for forming telescoping joints between the conduit portions 
of adjoining wall plates. 
Wall plates 82 define horizontally extending bores 91 enabling reinforcing 
metal rods to be inserted into horizontally aligned bores in an assembled 
row of wall plates, the bores being filled with concrete after the wall 
has thus been reinforced. Vertical bores 93 may also be provided for the 
same purpose. Furthermore, as shown, the wall assembly may be further 
improved by providing a tenon-and mortise joint 94, 95 along the abutting 
edges of the wall plates. 
In this manner, a tightly closed wall structure is produced.