AU2005279670B2

AU2005279670B2 - Collector module for generating thermal and electric power

Info

Publication number: AU2005279670B2
Application number: AU2005279670A
Authority: AU
Inventors: Martin Hadlauer
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-08-31
Filing date: 2005-08-29
Publication date: 2010-04-29
Anticipated expiration: 2025-08-29
Also published as: AU2005279670A1; EP1819968A1; ATE454595T1; EP1819968B9; EP1819968B1; DE502005008846D1; AT500760A2; AT500760B1; ES2342780T3; WO2006024060A1

Abstract

Disclosed is a tracking solar collector module which is characterized in that a reflector unit (1) directs the beams at an angle towards the rear in an intersecting manner onto a ring absorber (5) comprising cooled solar cells or directs the beams onto a central absorber (3) without the beams intersecting each other.

Description

1 Solar collector system for generating thermal and electric power [001] The invention on hand refers to solar collector systems, which require two-axled tracking systems. The solar collector modules are consisting each of the basic units, - mirror, thermal absorber and supporting structure with connection devices. [002] Appropriate collector systems are described very detailed in the patent filing A1000 2003. Depending on the collector type, the absorber is either provided with a thermal selective coating or is equipped in addition with solar cells. The solar cells get illuminated by the mirrors with high intensity of sun-light and get cooled by a heat exchanger, which is flown through with liquid. In the ideal case not only the electrical power but also the produced heat is used. According to the laws of physics approximately 50% of the incident radiation gets reflected at the solar panels. Therefore, for achieving a good thermal performance, the radiation which is reflected by the solar cells should be brought to a further absorber. The decision, whether to use mainly thermal collectors with high temperatures or solar cell collectors with hybrid function, is often very difficult and fundamentally depending on the future innovations in the solar cell sector. [003] Object of the present invention is now, to provide a modular assembling system for this two complete different collector types in the usage, which creates the possibility of refitting at low costs thermal collectors to hybrid collectors and replacing out of date solar cells with the latest technology. Moreover is important, that the reflected radiation from the solar cells get used. [004] According to the invention this is reached by directing the mirror rays over cross to a cylindrical solar cell configuration. The remaining part of the light, which is not absorbed gets directed to another central positioned absorber. The modular assembling system gets obtained by separating structurally the ring absorber, consisting of the cylindrical solar cell arrangement and a cooling body, from the central positioned absorber. [005] Ideally the ring absorber and the central absorber are hydraulically flown through in series, in which the cold coolant is fed into the upper part of the ring absorber. To keep the temperature of the solar cells as low as possible, the ring absorber is separated thermally from the considerably warmer central absorber. For providing this function a plastic ring with low heat conductivity might be the ideal component. The central absorber ideally has the design of a convex flattened dome, what leads to a high capture of reflected radiation. Due to the special mirror geometry, creating the crossing ray configuration accordingly to the invention, no shade throw arises to the solar panels. An additional advantage is, that the 2 outer rim of the mirror shifts outwardly, if one presupposes, the height will be kept constant. By that the mirror becomes a little flatter, which results in a better capture of diffuse sunlight at the absorbers. For the additional capture of diffuse sunlight and for keeping low the loss of energy caused by inaccuracies of the tracking system, the inner rim of the mirror shifts outwardly. Ideally the free area between the central absorber and the mirror is equipped with solar cells, which are not provided with a special cooling device. The equipping of the central absorber with solar cells is conceivable in the case special solar cells are used, which are designed to convert the reflected light-spectrum. Doing this, the main focus is the generation of electric power. Thermal energy eventually isn't used, just representing waste heat which requires a cooling device. According to the invention a completely new collector type for mainly thermal use is manufactured by using identical components, just replacing the ring absorber. Doing this, the central absorber gets moved upwardly, directly into the radiation cone of the mirror. At higher temperature requirements it is favourable, to provide a glass dome in front of the central absorber. Depending on temperature requirements the room inside can be evacuated or be filled with inert gas. This applies to both collector types equally, the thermal collector and the hybrid collector. [006] Broader characteristics and details of the present invention result from the following figure description: [007] Fig.1 shows a hybrid collector in the cross section. The ring absorber 5, consisting of the heat exchanger 5_2 and the solar cell arrangement 5_1, gets illuminated by a funnel-shaped mirror 1. A part of the radiation gets absorbed at the solar cells 5_1, the remaining part is directed to the central absorber 3. The solar cell arrangement (5_1) extends over the margin the heat exchanger (5_2) to the inner rim of the mirror (1), separated by a seal (8). The mirror 1 is joined flexibly to the ring absorber 5 by three or more bolts 2_1. This avoids possible fatigue failures, caused by temperature changes. Ring absorber 5 and central absorber 3 are assembled on a supporting structure 4. The supporting structure 4 has the function to separate thermally the two absorbers 5 and 3 and comprise the mechanical connection to the tracking system. In the here shown configuration the supporting structure 4 is subdivided into the subassemblies, carrier unit 4_3, plastic ring 4_2 and calotte 4_1. Conceivable is, to use one single unit 4, made of compound material, which at the same time has the functions of preventing gas diffusion and loss of heat. [008] Fig. 2 shows a thermal collector in the cross section. Between mirror and absorber a flat solar ring 6 without cooling device is provided. The mirror 1 is supported flexibly by three or more bolts 2_2, which are connected to the supporting structure 4. The absorber 3 is covered by a glass dome 7. At high temperature requirements the absorber 3 3 can be isolated thermally by providing vacuum in the inside of the glass dome. To be able to keep the vacuum for a long time appropriate diffusion-resistant materials and seals 9, 10 must get applied. [009] At the characteristics according to the invention, described and represented schematically in each of the figures it is pointed out, that the individual components can be manufactured with different methods and various materials.

Claims

1. Solar collector module comprising at least one absorber (5, 3), one mirror (1) and one supporting structure (4), characterized in that one mirror unit (1), usable for two types of solar collectors, either reflects the incident rays at an angle towards the rear in an intersecting manner onto a ring absorber (5) comprising cooled solar cells or directs the beams onto a central absorber (3) without the beams intersecting each other.

2. Collector module according to claim 1, characterized in that two absorbers (5, 3), which are separated structurally, - a ring absorber (5) with cooled solar cells and a central absorber (3), are provided, in which the mirror (1) illuminates the ring absorber (5).

3. Collector module according to any of the claims 1 to 2, characterized in that the central absorber (3) is laid out convex.

4. Collector module according to any of the claims 1 to 3, characterized in that the mirror (6) is assembled out of single segments.

5. Collector module according to any of the claims 1 to 4, characterized in that the surface of the central absorber (3) is equipped partly with a thermally selective coating and partly with solar cells.

6. Collector module according to any of the claims 1 to 5, characterized in that the solar cell component (5_1) extends over the margin of the heat exchanger (5_2) in the shape of a flat funnel, adjoining to the mirror (1) over a seal (8).

7. Collector module according to any of the claims 1 to 6, characterized in that the mirror (1) is supported by three or more bolts (2), which are fastened either on the heat exchanger unit (5_2) or on the supporting structure (4).

8. Collector module according to any of the claims 1 to 7, characterized in that the ring absorber (5) and the central absorber (3) are connected hydraulically in series, in which the cold coolant is fed into the upper part of the ring absorber (5). 5

9. Collector module according to any of the claims 1 to 8, characterized in that the glass dome (7) is pressed down and protected against pollution at the inside by a rubber seal.

10. Collector module according to any of the claims 1 to 9, characterized in that additionally to the rubber seal (10) another seal (9) is provided for the prevention of gas diffusion.