Photovoltaic thermal module with air heat exchanger

Abstract

The problem is solved as follows: the photovoltaic thermal module consists of a photovoltaic module, on the rear side of which facing away from the sun a heat exchanger is located. The heat exchanger consists of at least one conduit through which heat transfer fluid flows. The conduits (which are optionally enlarged by heat transfer surfaces) are disposed at a distance from the photovoltaic module such that they are in good contact with the ambient air and also thermally conductively connected to the photovoltaic module. The surface area and the amount of heat exchange to the ambient air are increased by the main orientation of the surfaces of the heat exchanger running transversely to the PV module. As a result, a good flow of ambient air around both the heat exchanger and the rear side of the PV module is made possible. The PVT module is used, in particular, in combination with heat pumps for supplying heat to and/or cooling buildings.

Claims

1. A photovoltaic thermal module for combined generation of electricity and low-temperature heat for heat pumps for generating hot water and building heat, and for building cooling, having a photovoltaic module, on the rear side of which, in the position of use, facing away from the sun, a heat exchanger is situated, wherein the heat exchanger is structured as a plate/air heat exchanger comprising a plurality of interstices, which comprises one or more lines and sheet-metal plates applied to them, wherein the sheet-metal plates are in thermally conductive contact with the photovoltaic module, wherein the heat exchanger comprises sheet-metal end pieces which are structured in such a manner that they serve directly for fixation of the plate/air heat exchanger on the photovoltaic module, wherein the heat exchanger contains at least one channel structure or line through which a liquid or gaseous heat carrier fluid flows, the at least one channel structure or line situated at a distance from the photovoltaic module, wherein the at least one channel structure or line not only stands in direct contact with the ambient air, but also is connected with the photovoltaic module in a thermally conductive manner to form a thermally conductive contact, wherein the thermally conductive contact between the at least one channel structure or line and the photovoltaic module is implemented by means of mechanical pressing combined with gluing, wherein the surface areas of the heat exchanger that stand in contact with the ambient air are disposed transversely to the plane of expanse of the photovoltaic module and lie directly on the photovoltaic module without coverage and connection over a full area of the photovoltaic module, wherein free spaces are provided between the surface areas of the heat exchanger, wherein the free spaces between the surface areas of the heat exchanger are configured to provide access to the ambient air for the photovoltaic module, and wherein, in conditions when the temperature of the heat carrier fluid is below a freezing point, an accumulation of an amount of ice occurs that does not close the plurality of interstices, and the accumulation of the amount of ice is higher at the at least one channel structure or line than at the photovoltaic module.

2. The combined photovoltaic thermal module according to claim 1, characterized in that the heat exchanger is built up from double-crosspiece profiles, which are disposed transversely to the photovoltaic module.

3. The combined photovoltaic thermal module according to claim 1, characterized in that the at least one channel structure or line of the heat exchanger has a surface area which is configured to increase in size from a first size to a second size.

4. The combined photovoltaic thermal module according to claim 3, characterized in that the heat exchanger has at least one line with surface-increasing ribs.

5. The combined photovoltaic thermal module according to claim 3, characterized in that the heat exchanger has at least one line with surface-increasing wires.

6. The combined photovoltaic thermal module according to claim 1, characterized in that the edge of the ribs or of the sheet-metal plates is bent away on the side facing the photovoltaic module, and as a result lies against the photovoltaic module with an increased contact surface.

7. The combined photovoltaic thermal module according to claim 1, characterized in that the photovoltaic module is transparent between the PV cells, and the heat exchanger is a dark color to absorb solar radiation.

8. The combined photovoltaic thermal module according to claim 1, characterized in that the photovoltaic module is transparent between the PV cells, and the heat exchanger is selectively coated to absorb solar radiation, at a reduced emission of infrared radiation.

9. The combined photovoltaic thermal module according to claim 8, characterized in that the photovoltaic thermal module is coupled with a heat pump, and the refrigerant of the heat pump flows directly through the at least one channel structure or line of the photovoltaic thermal module.

10. The combined photovoltaic thermal module according to claim 1, wherein the sheet-metal end pieces serve as a frame of the photovoltaic module.

Description

DESCRIPTION OF THE INVENTION

(1) In the following, concrete embodiments of the invention will be described using FIGS. 1 to 8.

(2) FIGS. 1a, b and c show a photovoltaic thermal module 1 according to claims 1 and 7 to 9. FIG. 1a shows the view of the module from above, 1b at a slant from below, and 1c a top view from below.

(3) Here, the heat exchanger 3 is configured as a plate/air heat exchanger 13, and is situated on the underside of the photovoltaic module 2. It consists of a meander-shaped line 5 (see FIG. 1c), which is connected, at the top and the bottom, in each instance, with a collector pipe 9. The collector pipes 9 allow easy parallel switching of multiple modules. The line 5 and the collector pipes 9 vertically penetrate a number of wave-shaped sheet metal plates 12 that run parallel. On the side, the plate/air heat exchanger 13 is delimited by a sheet-metal end piece 14 (not shown in FIG. 1c), for example. The sheet-metal end pieces 14 stabilize the photovoltaic module 2, and can be used for fixation of the photovoltaic thermal module 1 on an installation framework, i.e. a separate frame is not required. Furthermore, they protect the plate/air heat exchanger 13 against damage during installation. The 180? arcs of the meander-shaped line run within the horizontal indentations of the sheet-metal end pieces 14.

(4) The sheet-metal plates 12 are shorter at the location where an electrical connection box 17 of the photovoltaic module 2 is situated, so that room remains for the connection box. The line 5 can be shaped in such a manner that is runs next to the connection box 17 (see FIG. 1c); however, due to its distance from the photovoltaic module 2, it can also run by way of the connection box 17 (not shown). The connection box is shown at the bottom in FIGS. 1a and 1c, but it can also be disposed at the top.

(5) The upper and lower face side of the photovoltaic thermal module 1 are open, i.e. they do not have a frame. In this way, ambient air 7 can freely flow around the rear side of the photovoltaic thermal module with an air heat exchanger 1, and penetrate into the interstices of the plate/air heat exchanger 13 (see FIG. 1 a). In this regard, it is cooled and drops downward. The heat carrier medium 4, which flows within the collector 9 and line 5, generally flows from top to bottom for the purpose of reliable ventilation, so that an efficient counter-stream heat exchange or cross-counter-stream heat exchange occurs between the ambient air 7 and the heat carrier medium 4 (see FIG. 1c).

(6) The photovoltaic thermal module 1 is shown upright in FIG. 1a, b, c. According to the invention, it is likewise possible to structure the photovoltaic thermal module 1 transversely, wherein the sheet-metal plates preferably also run perpendicular from top to bottom, and the lines 5 run horizontally, so as to allow good ventilation of the line 5 and vertical flow of the ambient air 7 around the line.

(7) FIG. 2 shows a detail of the photovoltaic thermal module 1 shown in FIG. 1. The sheet-metal end piece 14, which is preferably produced as an aluminum extruded profile, is connected with the photovoltaic module 2 using a frame/gill profile 15. The sheet-metal plates 12 and the sheet-metal end piece 14 are additionally glued to the photovoltaic module 2 using an adhesive 16. The collector pipe 9 has a widened region on its left outer side, to hold a plug-in connector for coupling with the next module.

(8) FIG. 3 shows the same detail as FIG. 2. Here, the sheet-metal plates 12 are bent away on the side with which they lie on the PV module 2. The bent-away regions 12b allow a connection with the PV module over its full area, i.e. improved heat dissipation and possibly easier application of the adhesive 16, for example in the form of a double-sided adhesive film.

(9) FIG. 4 shows the structure of the photovoltaic thermal module 1 implemented with a ribbed pipe. The ribs 10 are bent away on the side with which they lie against the PV module 2; this can be done during the bending process of the ribbed pipe. The bent-away or folded-over regions 10b allow a connection with the PV module over its full area, analogous to what was described above for sheet-metal plates 12 in FIG. 3. The ribbed pipe 10 can be bent in meander shape, for example, analogous to the structure shown in FIG. 1c.

(10) FIG. 5 shows the structure of the photovoltaic thermal module 1 implemented with extruded profiles: Multiple extruded profiles 11 are laminated onto the rear side of the PV module, with contact to the PV module 2 over its full area, using the adhesive 16. At a distance from the PV module, the line 5 is held with good heat conductivity by clipping it in. In a widened profile region that is situated above that, the collector pipe 9 is also held by clipping it in. Furthermore, the extruded profile is provided with heat exchanger surface areas 6 that increase the size of its surface. At the bottom, the profile has widened regions, which serve as a stable contact region during installation. Ambient air 7 can flow between the profiles 11 to the photovoltaic module 2.

(11) FIG. 6 shows the rear side of the photovoltaic thermal module structured in accordance with FIG. 5. The profile 11 is laminated on in pieces that run parallel, which are correspondingly shorter at the electrical connection box 17. A line 5 bent in meander shape, as well as the two collector pipes 9, are clipped into the profile 11. The photovoltaic thermal module is enclosed by the frame 18.

(12) The photovoltaic thermal module 1 is shown upright in FIG. 6. It can also be structured transversely, wherein the profiles 11 with the lines 5 preferably continue to be disposed horizontally, for good ventilation.

(13) FIG. 7 shows a cross-section of the photovoltaic thermal module 1 structured in accordance with FIGS. 5 and 6. The profiles 11, which are glued onto the PV module 2 using the adhesive 16, project downward beyond the frame 18 of the photovoltaic thermal module 1, so that the ambient air can flow around them well. The profiles have 45? bevels on the right and the left, so that the 180? arcs of the line 5, which is bent in meander shape, can run outside of the profile. The collector pipes 9 are affixed below the line 5.

(14) FIG. 8 shows, seen from below, the structure of the photovoltaic thermal module 1 implemented using micro-channel or double-crosspiece profiles. The double-crosspiece profiles 8 are structured as flat hollow profiles, the two opposite delimiting surfaces of which are connected with one another using crosspieces. The heat carrier fluid 4 flows through the double-crosspiece profiles 8. They are situated between two collector pipes 9 (here, only the detail with one collector pipe is shown). The heat carrier fluid 4 flows through the double-crosspiece profiles 8, in parallel. They are in contact with the rear side of the PV module 2, and connected using the adhesive 16. Ambient air 7 can flow through the double-crosspiece profiles 8 and the photovoltaic module 2.

(15) Instead of the embodiments described, other embodiments are also possible according to the invention: for example, according to claim 1, also other heat exchangers through which heat carrier medium flows are possible, for example heat exchangers produced using the roll-bond method. Instead of the meander-shaped piping shown in FIGS. 1 to 7, other types of piping are also possible, for example with parallel through-flow as in the structure according to FIG. 8. Vice versa, the structure with double-crosspiece profiles can also be implemented differently than between two collector pipes 9, for example in meander form.

REFERENCE SYMBOL LIST

(16) 1 photovoltaic thermal module with air heat exchanger 2 photovoltaic module 3 heat exchanger 4 heat carrier fluid channel structure or line for heat carrier fluid 5 surface-increasing heat exchanger surface area to the ambient air 6 ambient air 7 double-crosspiece profile or micro-channel profile 8 collector pipe 9 rib of ribbed pipe, 10b: folded-over part 10 profile 11 sheet-metal plate, 12b: bent-away part 12 plate/air heat exchanger 13 sheet-metal end piece of the plate/air heat exchanger 14 frame/gill profile 15 adhesive 16 electrical connection box 17 frame of the photovoltaic thermal module