WO2011009754A2

WO2011009754A2 - Solar collector and production method thereof

Info

Publication number: WO2011009754A2
Application number: PCT/EP2010/060009
Authority: WO
Inventors: Uwe Clement
Original assignee: Robert Bosch Gmbh
Priority date: 2009-07-24
Filing date: 2010-07-13
Publication date: 2011-01-27
Also published as: WO2011009754A3; DE202009018432U1; DE102009034658A1

Abstract

The invention relates to a solar collector and a method for producing a solar collector, particularly a flat-plate solar collector, comprising a glass cover (1), a particularly foamed housing (2), an absorber disposed therein and permeated by a solar fluid, and an insulation (4) on the side of the absorber (3) facing away from the glass cover (1). An aim of the invention is to provide a solar collector and a method for the production thereof, having low material requirements and low production times, and allowing robustness and good flexibility. The invention is characterized in that the housing (2) and at least one part of the absorber (3) are produced by deforming and/or master forming as an integrated component, and that the absorber (3) is encapsulated as a prefabricated component by the housing material when producing the foamed housing (2).

Description

DESCRIPTION

The invention relates to a solar collector with a housing and disposed therein, by a solar fluid permeable absorber according to the preamble of claim 1. Furthermore, the invention relates to a method for producing a solar collector according to the preamble of claim 8. solar panels, in particular solar panels are well known. Such solar collectors consist essentially of a glass cover, arranged therein, by a solar fluid permeable absorber and insulation on the side facing away from the glass cover side of the absorber. In this case, the absorber is designed as a channel through which the fluid can flow or as a fluid channel system. The fluid channel system in conventional embodiments comprises one or more tubes attached to respective brackets, for example, coated copper or aluminum sheets. The separately designed absorber is inserted into the solar collector housing, which also forms a separate assembly, and attached thereto. The absorber forms a separate unit. The effort to produce such a solar collector is considerable and therefore relatively expensive. In particular, the cost of materials and production times are high.

Also known are foamed housings, which are produced, for example, in a first production step and may even include preformed channels and structures, hydraulics, insulation, hydraulic connections, etc. In a second step, an absorber plate is then glued into the housing, for example, resulting in cavities in which the solar fluid can flow.

For reasons of robustness, especially because of the thermal expansion, the housing and the absorber are made of the same material. With other material combinations, there is otherwise a risk that leaks and thus leakage of the solar fluid may occur. In order to obtain a tightly sealed fluid space, the materials of the housing, the absorber plate and the adhesive must be precisely matched to one another with this concept. These include chemical resistance, thermal and mechanical properties, etc. This presents a challenge in development and manufacturing. The invention has for its object to provide a solar collector and a method for its production in order to overcome the disadvantages of the prior art. In particular, it is an object of the invention to provide a solar collector and a manufacturing method, which require a lower material cost and less-time manufacturing than before and allow robustness and good flexibility.

This is achieved by the objects with the features of claims 1 and 8 according to the invention. Advantageous developments can be found in the dependent claims. The solar collector according to the invention is characterized in that the housing and at least part of the absorber is produced by forming and / or prototyping as an integrated component and that the absorber is enclosed as a prefabricated, fluid-carrying component in the manufacture of the foamed housing from the housing material. For this purpose, the absorber is selected in its embodiment as a prefabricated component from the group of heat exchangers, namely parallel or structured sheets or plates and / or foils in the form of Plattenwärmeübertragern, individual, serially or parallel interconnected pipes in the form of tube bundle, harp and meander absorbers or flat flow through absorbers. The material of the absorber as a prefabricated component is in its embodiment selected from the group of large-pore and open-cell foams as well as plastic, rubber and / or ceramic materials and / or metals.

As a prefabricated component, the absorber has inherent stability. This is designed for the required pressure resistance during a foaming process during manufacture of the housing, so that it is not compressed. Alternatively, a waiver of the inherent stability is possible. Then the components can be subjected to water or air pressure which is as great as the pressure which builds up within the tool and the foaming process. For this purpose, the pressure during the foaming process is determined at a time or over the entire production process.

In a further embodiment, the absorber has openings spaced apart from one another, through which the foam material flows during a foaming process during the manufacture of the housing in order to form connecting webs for increasing the stability and to completely foam and encase the absorber. These additional The resulting connecting webs increase the stability of the structure with respect to the internal pressure prevailing in the hollow body during later operation.

In a preferred embodiment, an insulation is provided on the side facing away from the glass cover side of the absorber. In this case, the insulation is arranged at a distance below the absorber, so that flows during a foaming process in the manufacture of the housing of the foam material, at least in the peripheral edge region, between the absorber and insulation. In an additional, alternative embodiment, an insulation on the side facing away from the glass cover side of the absorber can be fixed thereto or adjacent thereto. The insulation with the absorber then forms a foamable unit.

The inventive method for producing a solar collector, in particular solar flat collector, is characterized in that the housing and at least a part of the absorber are produced by forming and / or prototyping as an integrated component and that the forming with a foaming process, in particular with a spray process for the manufacture of long or continuous fiber reinforced sandwich components in the manner of a composite spray molding process (CSM) is performed. The foaming process is carried out with at least one to be introduced into the open mold release agent for better demolding, wherein the release agent forms the weather protection on the component to be produced and wherein the coating within the mold, a so-called in-mold coating, in particular based on polyurethane (PUR ) is sprayed on the entire surface of the tool.

In a preferred embodiment, the foaming comprises the steps of introducing at least one release agent into at least one mold, then introducing at least one liquid foaming material, which is optionally provided with reinforcing materials such as glass fibers and / or gas-fiber mats, into the mold, then inserting the Absorber, the insulation and / or other components to umschäumender components in the mold, and optionally the introduction of additional layers of foaming material and reinforcing materials. Finally follows the shaping of the foam material as a finished component. In a preferred embodiment, the foaming comprises the steps of introducing at least one release agent into at least one mold, then the introduction at least one liquid foaming material, which is optionally provided with reinforcing materials such as glass fibers and / or gas-fiber mats, into the mold and then the insertion of a previously manufactured by a foam processing method composite component of absorber and insulation. The absorber is at least partially enclosed by hard foam. If necessary, other components to be foamed can be inserted into the mold. In the same way, optionally further layers of foaming material and reinforcing materials can be introduced before, after curing, the last step is the opening of the molding tool for shaping the foaming material as a finished component.

In yet another embodiment of the method according to the invention, the foaming is carried out by a reaction injection molding method (RIM), wherein first the absorber, the insulation and / or other components to be foamed are inserted into the mold and then subsequently the foaming material in the closed tool is sprayed under pressure.

With the solar collector according to the invention and the method according to the invention for its production, disadvantages according to the prior art are avoided and the robustness is increased. In addition to a lower cost of materials, the invention has a positive effect on the production since shorter production times are necessary and good flexibility with regard to structure and material properties is made possible.

Due to the integrated construction, a compact construction is possible, which enables the production of very flat collectors, that is, flat collectors with a low collector height. Furthermore, can be saved by the integrated design up to 50% of the required in the prior art absorber material, usually the expensive material copper.

The sealing of the foam material against the solar fluid to corresponding absorber surfaces or inner surfaces is relatively simple and thus in another

Step in the pre-production of the absorber by infiltration, pouring or coating. In order that the plastic used remains solar-fluid-resistant over the entire service life, for example water-resistant, all surfaces in which the solar fluid contacts the absorber may preferably be infiltrated and / or coated with a protective coating, a so-called liner, or the like. The liner or a comparable substance can, for example, be sprayed on, dosed or applied in a dipping process. Eliminated, on the other hand, due to the inventive measures the application of an adhesive agent, such as an adhesive to connect items. This is a significant advantage, since it is no longer necessary to carefully apply or dose adhesive on all bearing surfaces between the absorber parts and the housing in order to seal fluid channels tightly and to form a functioning absorber. For this purpose, the production concept according to the invention provides prefabricated fluid-carrying elements or hollow bodies. The drawings illustrate an embodiment of the invention and the production thereof and show in the figures:

1 shows schematically a cross section through a solar collector according to the invention with a distance from the absorber insulation,

Fig. 2 shows schematically a cross section through a solar collector according to the invention with an absorber fixed insulation and

3 schematically shows three different embodiments of an absorber in the

Top view and in section along the line S-S, namely

3a as a porous foam body

3b as a combination of absorber tubes with at least one absorber sheet 3c as a flat hollow body The solar collector, in particular solar flat collector, consists essentially of a glass cover 1, a foamed housing 2, arranged therein, by a solar fluid permeable absorber 3 and an insulation 4 on the of the The housing 2 and at least a portion of the absorber 3 are produced by forming and / or prototyping as an integrated component, wherein the absorber 3 as a prefabricated component in the manufacture of the foamed housing 2 from the housing material, at least in the edge regions , is bordered. The absorber 3 can be designed according to FIG. 3 in various embodiments. As a porous foam body 31 according to Figure 3a, as a combination of absorber tubes 32nd with at least one absorber sheet 33 according to Figure 3b or as a flat hollow body 34 according to Figure 3b.

There are provided mutually spaced openings 5 in the absorber 3, flows through the during a foaming process in the manufacture of the housing 2 of the foam material to form connecting webs to increase stability and enclose the absorber 3.

The insulation 4 is provided on the side facing away from the glass cover 1 side of the absorber 3. According to FIG. 1, this is located at a distance below the absorber 3, so that during a foaming process during the production of the housing 2, the foam material also flows between the absorber 3 and the insulation 4. In contrast, as shown in FIG. 2, the insulation on the side facing away from the glass cover 1 side of the absorber 3 fixed thereto or arranged directly adjacent to this, so that the insulation 4 and absorber 3 form a einschäumbare unit.

Claims

1. Solar collector, in particular solar flat collector, comprising a glass cover (1), a particular foamed housing (2) arranged therein, by a solar fluid permeable absorber (3) and an insulation (4) on the side facing away from the glass cover (1) of the absorber (3),

characterized in that the housing (2) and at least a part of the absorber (3) is produced by forming and / or prototyping as an integrated component and that the absorber (3) as a prefabricated component in the manufacture of the foamed housing (2) surrounded by the housing material becomes.

2. Solar collector according to claim 1,

characterized in that the absorber (3) is selected as a prefabricated component in its embodiment from the group of heat exchangers, namely parallel or structured sheets or plates and / or foils in the form of Plattenwärmeübertragern, individual, serially or parallel interconnected tubes in the form of tube bundles -, harp and meander absorbers or surface traversed absorbers.

3. Solar collector according to claim 1 or 2,

characterized in that the material of the absorber (3) is selected as a prefabricated component in its embodiment from the group of large-pored and open-cell foams and the plastic, rubber and / or ceramic materials and / or metals.

4. Solar collector according to one of claims 1 to 3,

characterized in that the absorber (3) as a prefabricated component has an intrinsic stability, which is adapted to the required pressure resistance during a Schäu- mung process in the manufacture of the housing (2).

5. Solar collector according to one of claims 1 to 4,

characterized in that the absorber (3) has spaced apertures (5) through which during a foaming process in the manufacture of the housing (2) the foam material flows to form connecting webs to increase stability and encase the absorber (3).

6. Solar collector according to one of claims 1 to 5,

characterized in that an insulation (4) is provided on the side of the absorber (3) facing away from the glass cover (1) and that the insulation (4) is arranged at a distance below the absorber (3) so that during a foaming process ses during manufacture of the housing (2) of the foam material between the absorber (3) and insulation (4) flows.

7. Solar collector according to one of claims 1 to 6,

characterized in that an insulation (4) on the side facing away from the glass cover (1) side of the absorber (3) fixed thereto or adjacent to this, so that the insulation (4) with the absorber (3) a foamable unit forms.

8. A method for producing a solar collector, in particular solar flat collector comprising a glass cover (1), a particular foamed housing (2) arranged therein, by a solar fluid permeable absorber (3) and an insulation (4) on the of the glass cover ( 1) facing away from the absorber (3), according to one of claims 1 to 7,

characterized in that the housing (2) and at least a part of the absorber (3) are produced by forming and / or prototyping as an integrated component and that the forming with a foaming process, in particular with a spray process for producing long- or endless fiber reinforced sandwich components after Type of composite spray molding process (CSM).

9. Method according to one of claims 1 to 8,

characterized in that the foaming process is carried out with at least one to be introduced into the open mold release agent for better demolding, wherein the release agent forms the weather protection on the component to be produced and wherein the coating within the mold, a so-called in-mold coating, in particular Base of polyurethane (PUR), is sprayed on the entire surface of the tool.

10. Method according to one of claims 1 to 9,

characterized in that the foaming comprises the steps of:

Introducing the at least one release agent into at least one mold, introducing at least one liquid foaming material which is optionally provided with reinforcing materials such as glass fibers and / or gas-fiber mats, into the mold, inserting the absorber (3), the insulation (4) and / or other components to be foamed in the mold, optionally introducing further layers of foaming material and reinforcing materials and molding the foaming material to the finished component.

1 1. A method according to any one of claims 1 to 9,

characterized in that the foaming comprises the steps of:

Introducing the at least one release agent in at least one mold, introducing at least one liquid foaming material, which is optionally provided with reinforcing materials such as glass fibers and / or gas-fiber mats, in the mold, inserting a previously made by a foam processing method composite component of absorber (3) and insulation (4), wherein the absorber (3) is at least partially enclosed by hard foam, and / or other components to be foamed into the mold, optionally introducing further layers of foaming material and reinforcing materials and forming the foaming material to the finished component.

12. The method according to any one of claims 1 to 9,

characterized in that the foaming is carried out by a reaction injection molding method (RIM), wherein first the absorber (3), the insulation (4) and / or other components to be foamed are placed in the mold and then the foaming material is sprayed into the closed tool under pressure.

13. The method according to any one of claims 1 to 12,

characterized in that the absorber as a prefabricated component during the foaming process with water or air pressure is applied, said pressure being as large as the pressure which builds up within the tool and the foaming process, and wherein the pressure during the foaming process at a time or over the entire manufacturing process is determined.