Heat exchange device for a photovoltaic module, and system, uses and method therewith

Abstract

The invention discloses a heat exchange device (1) for a photovoltaic module (2), the heat exchange device (1) having: a frame (3) with a cover (4), wherein the frame (3) can be attached to the rear side of the photovoltaic module (2), so that a hollow space (5) can be formed within the frame (4) and between the photovoltaic module (2) and the cover (4); a thermally conductive element (6) which is provided in the hollow space (5) and has support regions (15) for support on the photovoltaic module (2); an inlet (7) into the hollow space (5) and an outlet (8) out of the hollow space (5) for a gaseous heat exchange medium; wherein the thermally conductive element (6) is designed to allow heat exchange between the photovoltaic module (2) and the heat exchange medium flowing between the inlet (7) and the outlet (8) in the hollow space (5).

Description

[0001] Heat exchange device for a photovoltaic module, as well as system, uses and methods thereof

[0002] TECHNICAL FIELD

[0003] The invention relates to a heat exchange device for a photovoltaic module, a system with the heat exchange device and the photovoltaic module, a system with the heat exchange device and with a supply device for a heat pump, uses of the heat exchange device and the systems, and methods with the heat exchange device.

[0004] STATE OF THE ART

[0005] Heat exchangers for photovoltaic modules are well known. Collectively, these are also referred to as combined photovoltaic-thermal modules. The goal of combining photovoltaic modules with solar thermal collectors is generally to increase the area-related efficiency and generate both electricity and usable heat. The side of the photovoltaic module facing away from the sun is usually equipped with a heat exchanger, through which a liquid or gaseous heat transfer medium flows, making a portion of the solar radiation not converted into electrical energy and absorbed usable in the form of heat.

[0006] However, such heat exchangers for photovoltaic modules have not yet established themselves on the market. Reasons for this include, for example, a regularly negative cost / benefit ratio, increased complexity, increased maintenance effort, and often insufficient efficiency of such heat exchangers. EP 2 655 759 B1 accordingly discloses a building-integrated thermoelectric hybrid roof system. This system provides a roof comprising the following: a plurality of metal slats mounted horizontally on a plurality of wooden slats mounted vertically above the roof, each of the plurality of metal slats having a longitudinal channel extending in a longitudinal direction; a liquid-containing heat pipe extending longitudinally along the longitudinal channel and mounted in each of the plurality of metal slats such that the metal slat alone supports the heat pipe;a heat exchanger connected to the heat pipe; a pump connected between the heat pipe and the heat exchanger to circulate the fluid through the heat pipe; a plurality of solar-electric roof tiles mounted on the plurality of metal battens such that the metal batten alone holds the heat pipe and the plurality of solar-electric roof tiles, each of the plurality of solar-electric roof tiles being a building-integrated photovoltaic roof tile having a solar module bonded to a fiber cement tile and connected in series to form a string;

[0007] Such complete fluid-carrying systems are complex and expensive to install, require intensive maintenance, and often do not even cover their initial costs. Furthermore, the efficiency of such systems is not optimal.

[0008] EP 3 408 869 B1 further discloses a hybrid solar panel comprising: a photovoltaic module having a front side and a back side, a heat exchanger arranged opposite the back side of the photovoltaic module, a cooling fluid circulating in the heat exchanger to absorb the heat of the photovoltaic module, the heat exchanger having a heat exchange area arranged beneath the photovoltaic module and in which the cooling fluid flows, this fluid flowing between an inlet area and an outlet area, internal channels extending over the entire surface of the exchange area, the heat exchange area being formed by a double-walled hollow chamber plate, this hollow chamber plate consisting of an upper wall and a lower wall extending between two lateral ends of the plate and between which hollow chambers are arranged,and these hollow chambers are in the form of adjacent internal channels which are in fluid communication with the inlet and outlet areas.

[0009] This hybrid solar panel is not optimized for flow and therefore requires improvement in efficiency. For example, its air supply and exhaust are lossy and cannot be connected with conventional piping, which is why transition pieces are required. Furthermore, the production of the hybrid solar panel is complex, as special (milled) metal profiles are required.

[0010] Another problem with photovoltaic modules with a combined heat exchanger is that the different thermal expansion of the heat exchanger on the back of the photovoltaic module and the photovoltaic module itself leads to thermal stresses, which can cause material fatigue. A further disadvantage of conventional systems is that, compared to a conventional photovoltaic module, the module temperatures can rise if the flow of the heat exchange medium fails or is insufficient, thus reducing the power yield. Therefore, there is a need for optimization in this regard as well.

[0011] In addition, a general problem with conventional photovoltaic modules with a combined heat exchanger is that, due to the rear insulation, they generally have a greater problem with the heat generated, which reduces the yield of the photovoltaic modules.

[0012] Another disadvantage of conventional photovoltaic modules with combined heat exchangers is that they often cause unwanted noise due to flow-acoustic phenomena.

[0013] Heat pumps are also known. These are used, for example, for heating buildings.

[0014] It is an object of the invention to provide an optimized heat exchange device for a photovoltaic module, optimized methods with the heat exchange device, an optimized system with the heat exchange device and the photovoltaic module, an optimized system with the heat exchange device and a supply device for a heat pump, as well as optimized uses of the heat exchange device and the systems.

[0015] In particular, an object of the invention may be to simplify the construction of the heat exchange device and / or the assembly of the same on the photovoltaic module, in particular in order to reduce costs.

[0016] A further object of the invention may be to optimize the service life of the heat exchange device.

[0017] An additional object of the invention may be to facilitate the assembly of the heat exchange device.

[0018] A further object of the invention may be to improve the heat exchange between the photovoltaic module and the heat exchange device. A further object of the invention may therefore be to propose a heat exchange device whose configuration allows for optimized efficiency.

[0019] A further object of the invention may also be to provide a low-noise heat exchange device.

[0020] The above-mentioned task(s) or the potential individual problems may also relate to individual aspects of the overall system, for example to the profiles disclosed herein or to individual components of the heat exchange device.

[0021] This above-mentioned problem(s) is / are solved by the subject matter of claim 1. Further aspects and advantageous developments are the subject matter of the dependent claims.

[0022] According to one aspect, a heat exchange device for a

[0023] Photovoltaic module provided, the heat exchange device comprising: a frame with a cover, wherein the frame can be attached to the back of the photovoltaic module so that a cavity can be formed within the frame and between the photovoltaic module and the cover; a heat conducting element provided in the cavity with support areas for resting on the photovoltaic module; an inlet into the cavity and an outlet from the cavity for a gaseous heat exchange medium; wherein the heat conducting element is designed to enable heat exchange between the photovoltaic module and the heat exchange medium flowing in the cavity between the inlet and the outlet.

[0024] According to a further development of this aspect, a heat exchange device is provided, wherein the cavity is rectangular and the heat exchange device is designed such that a flow clearance, which is preferably wedge-shaped or trapezoidal in plan view, is provided on the inlet side and / or outlet side in the cavity.

[0025] According to a further development of one of the above aspects, a heat exchange device is provided, wherein the heat-conducting element is provided by at least one folded, kinked and / or bent sheet such that flow channels running alongside one another are provided for the flow of the heat exchange medium in the cavity; wherein the flow channels preferably run parallel; and wherein the flow channels are preferably provided over at least 80% of the width of the heat exchange device. The sheet can also be folded. According to a further development of one of the above aspects, a heat exchange device is provided, wherein the heat-conducting element is preferably made of aluminum; and / or the heat-conducting element is in one piece; and / or the support regions are provided as flat surfaces.

[0026] According to a further development of one of the above aspects, a heat exchange device is provided, wherein the heat conducting element has the support regions such that they can lie flat on the photovoltaic module; and the heat conducting element has protruding regions which protrude into the cavity.

[0027] According to a development of one of the above aspects, a heat exchange device is provided, the heat exchange device further comprising: a fan which is provided at or in the inlet or at or in the outlet for generating a volume flow of the heat exchange medium in the cavity, and preferably a heating element which is provided at or in the inlet for heating the heat exchange medium, wherein preferably the fan and the heating element are provided as a structural unit.

[0028] According to a further development of one of the above aspects, a heat exchange device is provided, wherein the heat exchange medium is air; and / or the inlet and the outlet each have an insulating bushing or a seal for sound insulation.

[0029] According to a further development of one of the above aspects, a heat exchange device is provided, wherein the heat conducting element has regions projecting into the cavity, which are formed in the cross-sectional profile, preferably at least largely, in triangular shape, in diamond shape, in pear shape or in spherical shape.

[0030] According to a development of one of the above aspects, a heat exchange device is provided, the heat exchange device further comprising: a recess in the cover; a thermo-reactive closure element provided in or on the recess, for example a lip made of bimetal, which is designed such that the recess is open above a predefined limit temperature and that the recess is closed below the predefined limit temperature.

[0031] According to a further aspect, a system with a heat exchange device according to one of the preceding aspects is provided, the system comprising: a photovoltaic module, wherein the heat exchange device is provided on the rear side of the photovoltaic module and / or a supply device for a heat pump, which is fluidly connected to the outlet via a piping in order to supply the heat exchange medium from the heat exchange device to the heat pump, wherein the supply device is preferably provided in front of or on the heat pump in such a way that the heat pump is supplied with the heat exchange medium on the inlet side.

[0032] According to a development of one of the above aspects, a system is provided, the system further comprising: a transparent front cover on the photovoltaic module; and / or insulation on the back of the heat exchange device; and / or at least one wind deflector which is attached to the sides of the photovoltaic module or the heat exchange device and which protrudes forward from the photovoltaic module. According to a further aspect, a method with the heat exchange device or with the system is provided, the method comprising the following steps: generating a flow of the heat exchange medium in the cavity of the heat exchange device; heating the heat exchange medium in the cavity of the heat exchange device by heat exchange with at least the heat-conducting element.

[0033] According to a further aspect, a method is provided with the above heat exchange device or with the above system, the method comprising the following steps: energizing the heating element to heat the heat exchange medium; energizing the fan to convey the heat exchange medium from the heating element to the heat conducting element; heating the heat conducting element by the heated heat exchange medium.

[0034] According to a development of the above aspect, the method further comprises the following step: heating the photovoltaic module to a temperature, for example 2 or 4 degrees Celsius, such that snow crystals located on the surface of the photovoltaic module are melted. To determine a suitable time for heating the photovoltaic module, the heat exchange device according to one of the above aspects can further comprise a sensor for detecting snowfall or a device for determining a probable imminent or ongoing snowfall. Such a device for determining a probable imminent or ongoing snowfall can obtain the weather information required for this purpose, for example via a network and / or a weather service.According to a further aspect, the heat exchange device or system is used to heat an infrastructure, for example a building.

[0035] According to a further aspect, the system is used for de-icing or snow removal from the photovoltaic module. The thermal energy required for this can be provided either by the heating element or by another thermal source, for example, a building.

[0036] According to a further aspect, the system is used for, preferably preventively, heating the photovoltaic module. For example, the photovoltaic module can be preventively heated before snow falls or before snow crystals adhere to the surface of the photovoltaic module and ice forms. Furthermore, the photovoltaic module can be heated, for example, when rapid snowfall or ice accumulation is detected on the photovoltaic module.

[0037] The advantages of the above aspects and details thereof will become apparent from the following description of the associated embodiments.

[0038] In general, the heat exchange device according to the above aspects is integrated into an energy management system, for example into a building heating system, via piping.

[0039] Although all the above individual features and details of a

[0040] Aspect of the invention and the developments of this aspect are described in the context of the heat exchange device and the associated systems, individual features and details of this device and the system are also disclosed as such independently of the heat exchange device.

[0041] In particular, a device for preventing overheating of a photovoltaic module is described, independent of the heat exchange device, which device has the thermoreactive closure element. This can also be used in other types of heat exchangers for a photovoltaic module.

[0042] The heat exchange device according to the invention is explained in more detail below in exemplary embodiments and individual aspects with reference to the figures of the drawing:

[0043] Fig. 1 shows a three-dimensional overview view of a heat exchange device according to an embodiment of the invention;

[0044] Fig. 2 shows a three-dimensional exploded view of the heat exchange device of Fig. 1 from a different perspective;

[0045] Fig. 3 shows a plan view of the heat exchange device of Figures 1 and 2;

[0046] Fig. 4 shows a schematic view of the heat exchange device of Figs. 1 to 3;

[0047] Fig. 5 shows exemplary profiles of the heat-conducting element according to a modification of the embodiment of Figures 1 to 4; Fig. 6 shows a partial cross-sectional view through a heat exchange device, which is a modification of the embodiment of Figures 1 to 4;

[0048] Fig. 7 shows a schematic oblique view of the modification of Fig. 6;

[0049] Fig. 8 shows a schematic section of a modification of the heat exchange device of Figures 1 to 4;

[0050] Fig. 9 shows an exploded view of the modification of the heat exchange device of Fig. 8;

[0051] Fig. 10 shows an addition to the heat exchange device of Figures 1 to 4;

[0052] Fig. 11 shows an alternative addition to the heat exchange device of Figures 1 to 4;

[0053] Fig. 12 shows a plurality of heat exchange devices 1 of Figures 1 to 4 with a plurality of wind deflectors;

[0054] Fig. 13 shows a schematic representation of a system with the heat exchange device of Figures 1 to 4 and with a supply device for a heat pump;

[0055] Fig. 14 shows a section through an exemplary structural embodiment of the feed device of Fig. 13. DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0056] Various embodiments of the present disclosure are disclosed below, by way of example only, with reference to the accompanying drawings. However, embodiments and terms used therein are not intended to limit the present disclosure to specific embodiments, and it should be construed to include various modifications, equivalents, and / or alternatives according to the embodiments of the present disclosure.

[0057] If more general terms are used in the description for features or elements shown in the figures, it is intended that not only the specific feature or element in the figures is disclosed to the person skilled in the art, but also the more general technical teaching.

[0058] With regard to the description of the figures, the same reference symbols may be used in the individual figures to refer to similar or technically corresponding elements. Furthermore, for the sake of clarity, more elements or features may be depicted with reference symbols in individual detailed or partial views than in the overview views. It is assumed that these elements or features are also disclosed accordingly in the overview views, even if they are not explicitly listed there.

[0059] It is to be understood that a singular form of a noun corresponding to an object may include one or more of the things, unless the context in question clearly indicates otherwise.

[0060] In the present disclosure, a term such as "A or B," "at least one of A or / and B," or "one or more of A or / and B" may include all possible combinations of features listed together. Terms such as "first," "second," "primary," or "secondary" used herein may represent various elements regardless of their order and / or meaning and do not limit corresponding elements. When an element (e.g., a first element) is described as being "operably" or "communicatively" coupled or connected to another element (e.g., a second element), the element may be connected directly to the other element or may be connected to the other element via another element (e.g., a third element).

[0061] For example, a term "configured to" (or "adapted to") used in the present disclosure may be replaced by "suitable for," "suitable for," "adapted to," "made to," "capable of," or "designed to," depending on what is technically feasible. Alternatively, in a particular situation, a term "device configured to" or "adapted to" may mean that the device can operate in conjunction with another device or component, or can perform a corresponding function.

[0062] All size specifications given in "mm" are to be understood as a size range of +- 1 mm around the specified value, unless another tolerance or other

[0063] Areas are explicitly stated. It should be noted that the present individual aspects, for example the heat-conducting element, are disclosed separately from or separately from the heat exchange device herein as individual parts or individual devices. It is therefore clear to the person skilled in the art that individual aspects or system components are also disclosed individually. In the present case, the individual aspects or system components are disclosed in particular in the subchapters marked with brackets. It is intended that these individual aspects can also be claimed separately.

[0064] Furthermore, for the sake of clarity, not all features and elements are individually identified in the figures, especially when they are repeated. Rather, the elements and features are identified as examples. Analogous or identical elements are to be understood as such.

[0065] Heat exchange device

[0066] Fig. 1 shows a three-dimensional exploded view of the heat exchange device 1 according to an embodiment of the invention. Fig. 2 shows a three-dimensional exploded view of the heat exchange device 1 of Fig. 1 from a different perspective. Fig. 3 shows a plan view of the heat exchange device 1 of Figs. 1 and 2. Fig. 4 shows a schematic view of the heat exchange device 1 of Figs. 1 to 3.

[0067] In Figures 1 and 2, arrow V indicates the front view of the heat exchange device 1, and arrow H indicates the rear view of the heat exchange device 1. This view corresponds to the arrangement of the heat exchange device 1 on the rear side of the photovoltaic module 2. The width direction of the heat exchange device 1 corresponds to the direction of the smaller extension of the heat exchange device 1, and the length direction of the heat exchange device 1 corresponds to the direction of the larger extension of the heat exchange device 1.

[0068] Figures 1 to 4 show a heat exchange device 1 for a photovoltaic module 2, which is indicated here by a black area, wherein the heat exchange device 1 has a frame 3 and a cover 4.

[0069] The frame 3 is preferably flush with the outer circumference of the photovoltaic module 2 so that the maximum area of ​​the rear of the photovoltaic module 2 can be used. The cover 4 is provided on the frame 3 and covers the frame 3 completely. This cover 4 can be a simple sheet or plate, or it can be designed as an insulating cover 4 and consist of a heat-insulating material, for example foam. Alternatively, the frame 3 can also be not flush with the outer circumference of the photovoltaic module 2, for example offset inwards.

[0070] The frame 3 and the cover 4 (partially enclosed) form a cavity 5 in which a heat-conducting element 6 is provided. When the heat exchange device 1 is attached to the photovoltaic module 2, the cavity 5 is largely or completely enclosed. The heat-conducting element 6 can be attached to the frame 3, to the cover 4 and / or preferably to the photovoltaic module 2. For example, the heat-conducting element 6 can also be attached only to the photovoltaic module 2 and can represent an insert in the cavity 5.

[0071] The heat-conducting element 6 is preferably provided by at least one folded or bent sheet metal 6, so that a plurality of flow channels 11 is provided in the heat-conducting element 6. These flow channels 11 preferably run parallel and can preferably be provided over at least 80% of the width of the heat exchange device 1. From the perspective of the cover 4, the flow channels 11 can be provided both above and below the heat-conducting element 6, whereby the flow cross-section is maximized and the pressure loss is reduced. The speed of the heat exchange medium relative to the heat-conducting element is therefore also low, which promotes heat exchange.

[0072] The at least one heat-conducting element 6 or sheet 6 can be designed, for example, as a trapezoidal sheet, or as shown in Figures 1 and 2, as a triangular sheet. The triangularly protruding parts of the heat-conducting element 6 can also be referred to as (triangular) fins.

[0073] The heat-conducting element 6 or the sheet metal 6 has support areas 15 which can lie flat on the photovoltaic module 2. These support areas 15 provide a surface for heat exchange with the photovoltaic module 2. The support areas 15 can also serve for the efficient and durable fastening of the heat-conducting element 6 with a thermally conductive adhesive. The present construction with the heat-conducting element 6 also minimizes the thermal stress acting on the heat exchange device and the photovoltaic module. Furthermore, the heat-conducting element 6 or the sheet metal 6 has protruding areas 16 which provide a surface for heat exchange with the gaseous heat exchange medium.

[0074] The design of the heat conducting element 6 explained above improves heat exchange while at the same time keeping manufacturing and assembly costs low.

[0075] The heat-conducting element 6 can also consist of several adjacently arranged sheets 6 or individual elements. The heat-conducting element 6 can also be made of metal, for example, aluminum. This allows for optimal heat conduction at low cost.

[0076] The cover 4 can have an opening for an inlet 7 and another opening for an outlet 8. Alternatively, the inlet 7 and the outlet 8 can also be provided in the frame 3.

[0077] The openings for the inlet 7 and for the outlet 8 are preferably circular and serve, for example, for the connection of pipes (not shown) which are suitable for conducting a gaseous heat exchange medium, preferably air.

[0078] The inlet 7 and the outlet 8 can each have an insulating bushing 14 or a seal 14, which reduces the noise caused by the flow of the heat exchange medium. The vibrations, which are generally generated by the flow of the gas, also propagate in the solid body, whereby acoustic decoupling of the heat exchange device 1 from the piping of the latter advantageously contributes to noise insulation.

[0079] In Figures 1 to 4, the cavity 5 of the heat exchange device 1 is shown as rectangular, wherein the heat conducting element 6 provided in the cavity 5 is arranged such that a wedge-shaped or trapezoidal flow space 9 is provided on the inlet side and / or outlet side in the cavity 6, which serves to distribute the flow of the heat exchange medium in the cavity 5.

[0080] The inlet 7 and the outlet 8 are provided laterally in the cover 4 as viewed from above. The inlet 7 and the outlet 8 can preferably be provided opposite one another with respect to a center point M, see Fig. 3 and Fig. 4, so that the inlet 7 and the outlet 8 are each provided in the corner regions of the cover 4. Furthermore, the heat-conducting element 6 can be provided symmetrically with respect to the center point M.

[0081] In the wedge-shaped or trapezoidal flow space 9, its free cross-section gradually decreases from the side of the inlet 7 or the outlet 8, respectively, such that a more uniform distribution of the heat exchange medium in the flow channels 11 is realized across the width of the heat exchange device 1. This homogenizes the flow of the heat-conducting element 6, thereby improving the efficiency of the heat exchange device 1.

[0082] Not shown is an optional additional opening in the cover 4 or in the frame 3 for any condensation that may occur. However, this opening can be very small or designed in a labyrinthine manner, so that any loss through this additional opening is negligible.

[0083] Fig. 4 shows a schematic representation of the flow pattern of the heat exchange medium in the heat exchange device, starting from an overall inlet flow. The flow in the flow space is divided into individual flows which flow through the flow channels 11. For the sake of clarity, Fig. 4 only shows four of a plurality of resulting individual flows through the respective channels. At the outlet 8, the individual flows are again combined into an overall outlet flow A.

[0084] In Fig . 4 it can be seen that the total length of the individual flows is approximately equal to one another, whereby an approximate homogeneity of the flow of the heat conducting element 6 can be provided.

[0085] By selecting acute angles α and β, preferably less than 30 degrees, more preferably < 15 degrees, for the wedge shape or trapezoidal shape of the flow space 9, the desired flow distribution can be ensured on the one hand, while on the other hand the effective area of ​​the heat conducting element 6 can be kept comparatively large because the flow space 9 only takes up a small part of the length of the heat exchanger device 1. The acute angles α and β are each formed between the inlet and outlet inner edges of the frame 3 and the adjacent edge of the heat conducting element 6. The acute angles α and β can be the same, as shown in Fig. 4, but can alternatively also be different. The overall flow pattern in Fig. 4 is provided such that the pressure loss is low, while the flow-through area of ​​the heat conducting element nevertheless enables effective heat exchange.Likewise, with the present flow guidance, the noise development due to the flow is reduced, since only a single edge (the inlet-side edge of the heat conducting element 6) protrudes into the flow.

[0086] The electrical conversion efficiency of photovoltaic modules decreases with increasing temperature. For example, a typical photovoltaic module with a nominal power of 400 W can only deliver 320 W at 70 °C. Thus, the present heat exchange device 1 not only utilizes the heat generated by a photovoltaic module, but also cools the photovoltaic module, thereby increasing its efficiency.

[0087] The heat conducting element 6 is a structure which enlarges the area of ​​flow or flow around, thus improving the efficiency of the heat exchange device.

[0088] Profiles of the heat-conducting element 6

[0089] Fig. 5 shows exemplary profiles of the heat-conducting element 6 with their support areas 15 in a respective partial cross-sectional view through the heat exchange device 1 of Figs. 1 to 4.

[0090] Profile 6a is a multiply folded profile arranged at an angle to the surface of photovoltaic module 2. Profile 6b is a multiply folded profile arranged perpendicular to the surface of photovoltaic module 2. These profiles 6a and 6b allow the surface area for heat exchange to be maximized.

[0091] Profile 6c is a diamond-shaped profile, which can be produced, for example, by folding an aluminum sheet several times. This profile also provides a comparatively large surface area.

[0092] Profile 6d is a pear-shaped profile that protrudes into cavity 5. Profile 6e is a spherical profile. Profiles 6d and 6e have no sharp edges, which makes them favorable in terms of aeroacoustics.

[0093] All of the above-mentioned profiles enable the advantages explained above regarding the heat-conducting element 6 .

[0094] Overheating protection

[0095] Fig. 6 shows a partial cross-sectional view through a heat exchange device 1, which is a modification of the embodiment of Figures 1 to 4. Fig. 7 shows a schematic oblique view of this modification.

[0096] As a result of the rear-insulating cover 4, the photovoltaic module 2 gets warmer without forced ventilation than without the heat exchanger device 1. Furthermore, the heat transfer coefficient to the surroundings of photovoltaic modules is typically in the range of 7-14 W / m2 K, which means that the photovoltaic module can also be regarded as thermally insulating. Although this insulation on both sides is desirable, it also brings with it problems. While the bare photovoltaic module, for example, can get as hot as 65 - 75 degrees C with little or no wind and full sunlight, the temperature of the photovoltaic module rises to higher temperatures due to the heat exchanger device 1 with cover 4 and without forced ventilation. This should be avoided, particularly to protect the material and because of the rapid drop in efficiency.

[0097] For this purpose, an elongated recess 18 can optionally be provided in the cover 4 of the heat exchanger device 1, which recess has a thermo-reactive closure element 17, for example a bimetal lip. The closure element 17 is designed such that during normal thermal operation, the recess 18 remains tightly closed and, above a predefined threshold value, for example 75 degrees Celsius, the closure element 17 opens and exposes the recess 18. This release enables natural convection and temperature peaks can be avoided.

[0098] Fig. 7 shows a schematic oblique view of the modification of Fig. 6. The recess 18 is preferably provided on a side of the heat exchange device 1 which, in the installed state, is provided at the upper or higher end of the heat exchange device 1. The recess 18 is preferably arranged such that it opens into one of the flow spaces 9. Furthermore, the recess can be arranged approximately centrally and run in the width direction of the heat exchange device 1. The recess 18 is preferably elongated.

[0099] ventilation

[0100] Fig. 8 shows a schematic section of a modification of the heat exchange device 1 of Figures 1 to 4. For a better overview, Fig. 9 shows an exploded view of the modification of the heat exchange device 1 of Fig. 8.

[0101] Fig. 8 shows a fan 12, which is provided at or in the inlet 7 or at or in the outlet 8 for generating a volume flow of the heat exchange medium in the cavity 5. This allows for effective flow to the heat-conducting element 6. The fan 12 can be provided, for example, as an electric fan with a power in the low wattage range.

[0102] The integration of the fan 12 into the heat exchange device 1 allows for regulation or control of the flow per heat exchange device, the use of a plurality of inexpensive individual fans, and the provision of an integrated solution, thus eliminating the need for external fans. Individual ventilation of the flow enables better or individual adjustment of the optimal operating point (efficiency depending on the flow volume) of the heat exchange device 1.

[0103] Furthermore, the fan 12 can be used to use the heat exchange device 1 to transport excess heat, for example from building heat, into the photovoltaic module 2.

[0104] In addition to the fan 12, a heating element 13 can be provided (optionally), which is provided at or in the inlet 7 or at or in the outlet 8 for heating the heat exchange medium. This heating element 13 can be provided as a heating insert for joint installation with the fan 12, and thus as a structural unit with the fan 12 (i.e., can be installed together).

[0105] Photovoltaic modules often remain covered in snow for weeks or even months. Due to the snow's high reflectivity, the solar energy is often insufficient to melt this layer; a layer of hard snow forms, which is detrimental. This significantly reduces the photovoltaic module's output over the course of a year. Manually cleaning a photovoltaic module is often only an option in exceptional cases and involves considerable effort and a risk to people and equipment.

[0106] This problem is addressed here by the heating element 13. If snow falls and remains on the photovoltaic modules 2, the temperature of the photovoltaic modules is controlled via the existing ventilation by means of the fan 12 and the heating element 13. This temperature control can be achieved, for example, at +2 to +4 degrees Celsius in order to melt the snow crystals before they stick to the panel surface. The fan 12 and the heating element 13 can be controlled manually or automatically by means of a controller. Alternatively, the heating of the at least one photovoltaic module can also be achieved using thermal energy that is not provided by the heating element 13. For example, the thermal energy or heat can be provided by a building.

[0107] Fig. 10 shows an addition to the heat exchange device 1 of Figures 1 to 4. Fig. 11 shows an alternative addition to the heat exchange device 1 of Figures 1 to 4. Fig. 10 shows a transparent front cover 20, for example a double-wall plate 20, which is provided on the heat exchange device 1. This provides front-side insulation on the photovoltaic module 2. In addition, plate-shaped insulation 19 is also provided on the rear. The heat exchange device 1 is thus insulated like a sandwich, which can improve the heat yield. Fig. 11 corresponds to Fig. 10 with the only difference that spacer elements 21 are provided between the heat exchange device 1 and the double-wall plate 21 for spacing.The spacer elements 21 provide a gap between the photovoltaic module 2 and the transparent front cover 20, in which an insulating air cushion is formed, which further improves the insulation to the outside.

[0108] Fig. 12 shows a plurality of heat exchange devices 1 of Figures 1 to 4 with a plurality of wind deflectors 22. Thus, Fig. 12 also shows a system or systems comprising a heat exchange device and a photovoltaic module.

[0109] Between the heat exchange devices 1 shown in Fig. 12, arranged side by side, and the associated photovoltaic modules 2, wind deflectors 22 are provided, which protrude forward between them. These wind deflectors 22 are plate-shaped and can have openings to reduce wind load and shading.

[0110] Natural wind blowing across the photovoltaic module 2 impairs the efficiency of the entire device above a certain value by dissipating or losing heat. Wind deflectors 22 or wind fences 22, for example, vertically mounted perforated sheets or fine-mesh grids, can slow the adverse airflow and thus reduce the loss. The wind deflectors 22 can also be made of an at least partially transparent material in order to minimize the shadow cast on the photovoltaic module 2.

[0111] (System with the heat exchange device 1 and a supply device 31 for a heat pump 30)

[0112] Fig. 13 shows a schematic representation of a system with the heat exchange device 1 and a supply device 31 for a heat pump 30.

[0113] After heating the heat exchange medium in the heat exchange device 1, the gaseous heat exchange medium is conveyed via a piping 33 to the feed device 31, see arrow 34. This can be done, for example, by means of the blower 12 or by means of another blower in the piping 33 or in the feed device 31.

[0114] The supply device 31 is provided as a flat air outlet, which supplies the heat exchange medium flowing in the piping 33 to a heat pump 30, see arrow 32. In this respect, the supply device 31 enables a heat flow, preferably directed towards the heat pump via fins of the supply device 31, which supplies the heat collected by the heat exchange device 1 to the heat pump 30.

[0115] The supply device 31 can be provided as a flat air outlet such that it is located adjacent to or at a short distance from the inlet of the heat pump 30. The distance between the supply device 31 and the heat pump 30 can be dimensioned such that the heat pump remains functional even when the heat exchange device 1 is not in operation.

[0116] A heat pump 30 within the meaning of this application is a combined heat and power machine which, by expending technical work, absorbs thermal energy from a reservoir with a lower temperature (usually the environment) and transfers it as useful heat with a higher temperature to a system to be heated, for example a building.

[0117] The ratio of heat output delivered to the building to the electrical (compressor) power supplied is referred to as the coefficient of performance (COP) of heat pumps. The COP of a heat pump is influenced by many factors. One of these factors is the temperature of the heat pump's heat source (e.g., the outside air of a building). The general rule is that the COP is better the warmer the temperature of the heat source, or the smaller the temperature difference between the heat source and the heat pump's heat sink.

[0118] Thus, with the system shown in Fig. 13, the COP of the heat pump 30 can be advantageously increased, since the temperature of the source of the heat pump 30 or the reservoir is increased. This can improve the energy efficiency of the heat pump 30. In other words, the temperature difference between the environment and the heat sink (which is, for example, a heating flow) can be reduced.

[0119] Preferably, the supply device 31 is provided in front of or on the heat pump 30 in such a way that the heat pump 30 is supplied with the heat exchange medium on the inlet side.

[0120] Fig. 14 shows a section through an exemplary structural embodiment of the feed device 31 of Fig. 13.

[0121] The feed device 31 of Fig. 14 illustrates with the arrows 32 and 34 flows of the heat exchange medium which correspond to the air flows 32 and 34 of Fig. 13. The feed device 32 is provided as a flat air outlet and has (optional) slats 35 which direct the escaping flows onto an inlet of a heat pump 30 (not shown in Fig. 14 and surrounded by the feed device 32). In this respect, the feed device 31 of Fig. 14 is set up in such a way that it realizes a heat flow in the inlet of the heat pump 30 of Fig. 14 without blocking the inlet of the heat pump 30. The arrow 32 of Fig. 14 shows only an exemplary flow direction which exits from the opening surface of the feed device 31.

[0122] The supply device 31 can be designed in such a way that it allows mixing of the ambient air with the heat exchange medium.

[0123] The further advantages of the embodiment described herein and the associated aspects include the following key points: Increased solar yield by utilizing not only the electricity yield but also the heat yield with the same space requirement. Increased user yields even under limited radiation conditions. Rapid response of the heat exchanger device to changes in solar irradiation. The resulting warm air can be used directly. Retrofitting is easy. Leakage is unproblematic compared to liquid-based heat exchangers. The heat exchanger device disclosed here is frost-proof and requires only minimal upkeep and maintenance.

[0124] The embodiments and aspects disclosed herein are provided to describe and understand the disclosed technical matters and are not intended to limit the scope of the present disclosure. Therefore, the scope of the present disclosure should be interpreted as including any modifications or other various embodiments based on the technical spirit of the present disclosure.

Claims

Claims 1. Heat exchange device (1) for a photovoltaic module (2), the heat exchange device (1) comprising: a frame (3) with a cover (4), wherein the frame (3) can be attached to the back of the photovoltaic module (2) so that a cavity (5) can be formed within the frame (4) and between the photovoltaic module (2) and the cover (4); a heat-conducting element (6) provided in the cavity (5) with support areas (15) for support on the photovoltaic module (2); an inlet (7) into the cavity (5) and an outlet (8) from the cavity (5) for a gaseous heat exchange medium; wherein the heat-conducting element (6) is designed to enable heat exchange between the photovoltaic module (2) and the heat exchange medium flowing in the cavity (5) between the inlet (7) and the outlet (8).

2. Heat exchange device (1) according to claim 1, wherein the cavity (6) is rectangular and the heat exchange device (1) is arranged such that a flow clearance (9), which is preferably wedge-shaped or trapezoidal in plan view, is provided on the inlet side and / or outlet side in the cavity (6).

3. Heat exchange device (1) according to claim 1 or 2, wherein the heat-conducting element (6) is provided by at least one folded, kinked and / or bent sheet metal such that adjacent flow channels (11) are provided for the flow of the heat exchange medium in the cavity (5); wherein the flow channels (11) preferably run parallel; and wherein the flow channels (11) are preferably provided over at least 80% of the width of the heat exchange device (1).

4. Heat exchange device (1) according to one of the preceding claims, wherein: the heat-conducting element (6) is preferably made of aluminum; and / or the heat-conducting element (6) is in one piece; and / or the support areas (15) are provided as flat surfaces for support on the photovoltaic module (2).

5. Heat exchange device (1) according to one of the preceding claims, wherein: the heat-conducting element (6) has the support areas (15) such that they can lie flat on the photovoltaic module (2); and the heat-conducting element (6) has protruding areas (16) that protrude into the cavity (5).

6. Heat exchange device (1) according to one of the preceding claims, further comprising: a fan (12) which is provided at or in the inlet (7) or at or in the outlet (8) for generating a volume flow of the heat exchange medium in the cavity (5), and preferably a heating element (13) which is provided at or in the inlet (7) for heating the heat exchange medium, wherein preferably the fan (12) and the heating element (13) are provided as a structural unit.

7. Heat exchange device (1) according to one of the preceding claims, wherein the heat exchange medium is air; and / or the inlet (7) and the outlet (8) each have an insulating bushing (14) or a seal (14) for sound insulation.

8. Heat exchange device (1) according to one of the preceding claims, wherein the heat conducting element (6) has regions (16) projecting into the cavity (5) which are formed in the cross-sectional profile, preferably at least largely, in triangular shape, in diamond shape, in pear shape or in spherical shape.

9. Heat exchange device (1) according to one of the preceding claims, further comprising: a recess (18) in the cover (4); a thermoreactive closure element (17) provided in or on the recess (18), for example a bimetal lip, which is designed such that the recess (18) is open above a predefined limit temperature, and that the recess (18) is closed below the predefined limit temperature.

10. System with a heat exchange device (1) according to one of claims 1 to 9, the system comprising: a photovoltaic module (2), wherein the heat exchange device (1) is provided on the back of the photovoltaic module (2); and / or a supply device (31) for a heat pump (30), which is fluidically connected to the outlet (8) via a piping (30) in order to supply the heat exchange medium from the heat exchange device (1) to the heat pump (30), wherein the supply device (31) is preferably provided in front of or on the heat pump (30) in such a way that the heat pump (30) is supplied with the heat exchange medium on the inlet side.

11. System according to claim 10, the system further comprising: a transparent front cover (20) on the photovoltaic module (2); and / or insulation (19) on the back of the heat exchange device (1); and / or at least one wind deflector (22) which is attached to the sides of the photovoltaic module (2) or the heat exchange device (1) and which protrudes forward from the photovoltaic module (2).

12. Method with the heat exchange device (1) according to one of claims 1 to 9 or with the system according to one of claims 10 or 11, the method comprising the following steps: Generating a flow of the heat exchange medium in the cavity (5) of the heat exchange device (1); Heating the heat exchange medium in the cavity (5) of the heat exchange device (1) by heat exchange with at least the heat conducting element (6).

13. Method with a heat exchange device (1) according to claim 5, the method comprising the following steps: Energizing the heating element (13) to heat the heat exchange medium; Energizing the fan (12) to convey the heat exchange medium from the heating element (13) to the heat conducting element (6); Heating the heat conducting element (6) by the heated Heat exchange medium.

14. Use of the heat exchange device (1) according to one of claims 1 to 8 or of the system according to one of claims 10 or 11 for heating an infrastructure, for example a building.

15. Use of the system according to claim 10 or 11 for de-icing or removing snow from the photovoltaic module (2) by means of warm air.

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