RADIANT HEATING

Description

[0001] The invention relates to the field of heating systems and concerns a radiant heating system, such as can be used, for example, to heat individual areas in large, expansive, and / or high rooms. Furthermore, radiant heating can be used in other technical installations in which defined areas are to be efficiently heated primarily by radiation.

[0002] Tall and expansive spaces, such as factory halls, aircraft hangars, or similar, often require special heating systems to ensure effective and energy-efficient heating. For reasons of energy efficiency and cost-effectiveness, the heating systems used should be capable of maintaining the required thermal parameters only in selected locations or areas. These locations or areas could, for example, be staff rest areas or special production or storage zones. Other locations or areas with lower thermal parameter requirements can therefore be conditioned with less energy input. Similar tasks, namely the targeted supply of energy for heating purposes to limited local areas, can also arise in residential and public buildings, even for a limited period of time.Examples of this include entrance areas where service personnel are permanently stationed. Special heating solutions are also required for the targeted conditioning of glass panes that need to be protected from fogging or kept free of ice and snow, such as checkout areas or in automotive manufacturing.

[0003] Typically, so-called radiant heaters are used for these tasks. The term "radiant heating" generally refers to heating systems whose share of thermal radiation in the total heat output is significant. This share is of great importance for various heating tasks. This ultimately results in the general task of radiant heaters to increase the share of radiation as much as possible while achieving a high level of efficiency in relation to the final energy used.

[0004] In conventional radiant heating systems, thermal radiation originates entirely from thermal radiation. Here, the surfaces of bodies heated in various ways emit electromagnetic radiation in the projected amount, which arrives at the desired receiving location and is converted into sensible heat in solid bodies.

[0005] The power of the radiation emitted by surfaces is determined, among other things, by the temperature. It is proportional to the fourth power of the temperature. The resulting increased surface temperatures compared to the environment also have disadvantages. On the one hand, hazards can arise in terms of contact by people or the risk of fire. On the other hand, the surface also releases a significant amount of heat into the surrounding room air through convection, which in the majority of cases does not benefit the heating task and is therefore to be described as a loss and is therefore undesirable. The energy release from the surface, determined, among other things, by its surface temperature, is therefore desirable because of thermal radiation and advantageous due to its orientation and transfer to / to a specific location, but is often subject to losses due to convection into the room air.Furthermore, losses due to heat conduction can occur due to the chosen fastening method.

[0006] It is known from DE 20 2012 003681 U1, KR 10 1 059 950 B1, DE 10 2014 001 044 that radiant heaters based on LEDs (LED - light-emitting diode = semiconductor component) offer efficiency advantages over radiant heaters based purely on thermal radiation.

[0007] In these solutions, the propagation and transmission of energy by radiation for heating purposes is retained, but thermal radiation is no longer used primarily and exclusively as the radiation source. At least a portion of the emitted radiation in the desired wavelength range is generated by the recombination of charge carriers of opposite charge in the semiconductor material.

[0008] IR LEDs (infrared LEDs) are preferably used as LEDs, i.e. a semiconductor component that primarily emits electromagnetic radiation in the wavelength range > 0.7 µm, since the energy transfer for heating purposes does not affect the visual orientation of humans and animals.

[0009] Electromagnetic radiation in the wavelength range from 0.78 µm to 1000 µm is commonly referred to as infrared radiation. The practical generation of electromagnetic radiation by semiconductor components in this wavelength range for energy transmission for heating purposes ends at approximately 15 µm.

[0010] However, such semiconductor components do not completely convert the supplied electrical energy into radiation in the desired wavelength range. Additional heat is generated, which must be dissipated from the semiconductor body. This is achieved by heat sinks, which are typically placed on top of the semiconductor component and then dissipate heat to the environment, primarily through the physical transfer processes of convection and radiation.

[0011] According to DE10 2004 047 324 A1, a light-emitting diode arrangement is known which consists of a light-emitting diode chip with an optical element and a heat-conducting element through which the heat generated by the light-emitting diode chip is dissipated and guided to a cooling device which absorbs the heat from the heat-conducting element.

[0012] It is important that the LED emits radiation in the visible light wavelength range toward the optical element, and that the heat transferred from the LED chip to the heat-conducting element, preferably by thermal conduction, is transferred from the heat-conducting element to the cooling device, preferably by thermal conduction and / or convection. The cooling device preferably contains at least one of the following elements: heat sink, thermally conductive material, heat pipe, thermosyphon, fluid circuit, or fan.

[0013] DE 102 05 695 A1 discloses a headlight for vehicles in which several light sources, each with a light-emitting semiconductor component, are located on a carrier. The carrier is shaped into a reflector in the area of ​​the semiconductor components and has a projection running in the direction of radiation, which ends near the cover plate. The carrier dissipates heat and dissipates it primarily through the projection. This projection does not carry any semiconductor components and is therefore cooler. Since the projection runs near the cover plate, it is heated. This eliminates the need for a separate heater.

[0014] Furthermore, DE 10 2016 211 317 A1 discloses a radiant heater having at least one semiconductor component which emits at least radiation in the wavelength range > 0.7 µm and is partially surrounded by a heat sink, wherein at least one surface of the semiconductor component for emitting radiation in the wavelength range > 0.7 µm is not covered by the heat sink, and wherein the heat sink has at least one surface in the direction of radiation emission in the wavelength range > 0.7 µm, and the heat sink is arranged at least partially in positive contact with an insulation in the opposite direction to the radiation emission in the wavelength range > 0.7 µm.

[0015] DE 10 2019 203 593 A1 discloses a decorative heating panel with a light-emitting layer, which essentially consists of a decorative layer, a heating layer, and a light-emitting layer. The decorative layer is transparent or translucent to visible light, the heating layer emits infrared light, and the light-emitting layer emits visible light. The heating layer and the light-emitting layer are arranged on the back of the decorative layer, and at least one of the layers is transparent or translucent to visible and / or infrared light. In this heating panel, all three layers are arranged one above the other, and it combines the use of light and infrared radiation, with (IR) LED solutions also being mentioned for radiation emission.

[0016] According to EP 3 173 694 A1, a device for the combined emission of heat radiation and light is known. The device consists of a heat source emitting heat radiation and a light source, such as LEDs. The device comprises a plate-shaped base body on which a luminous element is arranged such that the emitted light from the luminous element enters the base body. Furthermore, the base body contains a scattering device that couples the light to the cover surface of the base body. A heating mat or IR LEDs are also provided as the heat source.

[0017] DE 10 2016 107 495 A1 discloses a multilayer carrier system and a method for its production and use. The multilayer carrier system comprises a ceramic substrate and a matrix module composed of heat-producing semiconductor components. The semiconductor components are arranged on the ceramic substrate, and the matrix module is electrically connected to a driver circuit via the ceramic substrate.

[0018] According to US 2016 / 368347 A1, a liquid heating device for a motor vehicle and corresponding heating and / or air conditioning systems are known. The liquid heating device consists of a metal body with a cavity through which the liquid to be heated flows. A heating rail is mounted on the metal body. This heating rail acts as an ohmic resistor, converting electrical energy into heat energy and transferring this heat energy to the liquid to be heated by conduction through the wall of the metal body and by convection.

[0019] Furthermore, from DE 10 2015 115 459 A1 a heating device with a heat radiator arrangement and a control unit is known, in which the heating elements of the heat radiator arrangement can be controlled independently of one another and the control unit is designed to adjust the power of the heat radiator arrangement by controlling at least a first heating element in such a way that the power of each first heating element always corresponds either to a predetermined minimum value or to a predetermined maximum value.

[0020] A disadvantage of the state-of-the-art solutions for radiant heating with semiconductor components is that part of the thermal energy generated by the radiant heating is still not used for the actual heating task and therefore the energy efficiency of radiant heating with semiconductor components is still inadequate.

[0021] The object of the present invention is to further increase the efficiency of radiant heaters with semiconductor components - that is, the ratio of the amount of energy arriving in the room area to be heated to the amount of energy supplied to the radiant heater.

[0022] The object is achieved by the invention defined in the claims. Advantageous embodiments are the subject of the dependent claims, whereby the invention also includes combinations of the individual dependent claims in the sense of an AND connection, as long as they are not mutually exclusive.

[0023] The radiant heater according to the invention has at least one semiconductor component which emits at least radiation in the wavelength range > 0.7 µm, which is partially surrounded by a heat sink, wherein at least one surface of the semiconductor component for emitting radiation in the wavelength range > 0.7 µm is not covered by the heat sink, and wherein the heat sink has at least one surface in the direction of radiation emission of the semiconductor components in the wavelength range > 0.7 µm, and the heat sink is arranged at least partially in at least positive contact with a thermal insulation in the opposite direction of the radiation emission of the semiconductor components in the wavelength range > 0.7 µm, wherein at least one ballast is also provided for converting the electrical energy for the operating mode of the semiconductor components,which is positioned with at least one surface on the surface of or partially in the heat sink and at least one surface of the ballast points in the direction of radiation emission of the semiconductor components in the wavelength range > 0.7 µm, and further device elements may be present.

[0024] Advantageously, IR-LEDs and / or IR-OLEDs are used as semiconductor components.

[0025] Furthermore, in addition to one or more semiconductor components which emit radiation in the wavelength range > 0.7 µm, one or more semiconductor components, such as LEDs and / or OLEDs, which emit radiation from the wavelength range > 0.4 µm can be present.

[0026] Also advantageously, the radiant heater comprises semiconductor components that emit radiation in the wavelength range > 0.7 µm and semiconductor components that emit radiation in the wavelength range from 0.4 to 0.78 µm.

[0027] Furthermore, the heat sink is advantageously made of copper, aluminum and / or graphite or is designed as a metal core circuit board.

[0028] And also advantageously, the thermal insulation consists of mineral, inorganic and organic insulating materials or insulation boards, advantageously of rock wool, glass wool, calcium silicate, foamed plastics, foamed elastomers, vacuum insulation boards, vegetable or animal fibers or recycled material.

[0029] It is also advantageous if the thermal insulation on the surface of the side facing away from the heating task has a low emission coefficient for thermal radiation, which is advantageously realized by an aluminum lamination.

[0030] It is also advantageous if the semiconductor component and / or the at least one ballast is not covered by the heat sink only on the surface for emitting radiation from the semiconductor components in the wavelength range > 0.7 µm.

[0031] It is furthermore advantageous if the heat sink is arranged in positive contact with an insulation on all surfaces, except on the surfaces on which the semiconductor components and / or the ballast are arranged and except on the surface in the direction of radiation emission of the semiconductor components in the wavelength range > 0.7 µm.

[0032] It is also advantageous if, as further device elements, structures are provided for restricting and / or obstructing the air flow over the surface of the radiant heater, which emits at least radiation from the semiconductor components in the wavelength range > 0.7 µm.

[0033] It is also advantageous if metal sheets or baffles are provided as structures to restrict and / or obstruct the air flow over the surface of the radiant heater, which emits at least radiation from the semiconductor components in the wavelength range > 0.7 µm.

[0034] It is also advantageous if, as structures for restricting and / or obstructing the air flow over the surface of the radiant heater, which emits at least radiation from the semiconductor components in the wavelength range > 0.7 µm, one or more ballasts are present which have a greater height difference of their surface in the direction of the radiation emission of the semiconductor components, compared to the surface in the direction of the radiation emission of the semiconductor components.

[0035] It is also advantageous if additional device elements such as covers, optical lenses and / or beam guiding elements that are permeable to radiation in the wavelength range > 0.7 µm are present.

[0036] Advantageously, the semiconductor components and / or the ballasts are arranged on and / or in and / or with the heat sink in a modular design, and the modules can be removed individually from the radiant heater.

[0037] It is also advantageous if one or more heat-insulating layers are present as further device elements, which are arranged between semiconductor components and / or ballast and / or heat sink, each as individual elements or as modules.

[0038] The solution according to the invention makes it possible for the first time to further increase the efficiency of radiant heaters with semiconductor components - that is, the ratio of the amount of energy arriving in the room area to be heated to the amount of energy supplied to the radiant heater - compared to the solutions of the prior art.

[0039] For the solution according to the invention, a radiant heater is present as a starting point, in which at least one semiconductor component which emits at least radiation in the wavelength range > 0.7 µm is partially surrounded by a heat sink, wherein at least one surface of the semiconductor component for emitting radiation in the wavelength range > 0.7 µm is not covered by the heat sink, and wherein the heat sink has at least one surface in the direction of radiation emission of the semiconductor components in the wavelength range > 0.7 µm, and the heat sink is arranged at least in the opposite direction of the radiation emission of the semiconductor components in the wavelength range > 0.7 µm at least partially in positive contact with a thermal insulation.

[0040] Based on such radiant heaters, according to the invention there is further provided at least one ballast for converting the electrical energy for the operating mode of the semiconductor components.

[0041] This ballast is positioned with at least one surface on the surface of the heat sink or partially within it, and at least one surface of the ballast faces in the direction of radiation emission from the semiconductor components in the wavelength range > 0.7 µm. By utilizing the radiation also emitted by the ballast for the heating task, the efficiency of the radiant heating is further increased by the inventive arrangement of the ballast.

[0042] The semiconductor components used are LEDs (LED - light-emitting diode = semiconductor component).

[0043] Radiant heaters with LEDs generally offer efficiency advantages over radiant heaters based on the use of thermal radiation alone. At least a portion of the emitted radiation is generated by the recombination of charge carriers of opposite charge in the semiconductor. This results in a lower surface temperature for the same surface-specific radiant power, which ultimately leads to reduced convective heat dissipation and thus lower convective loss. IR LEDs are preferably used, a semiconductor component that primarily emits electromagnetic radiation in the wavelength range > 0.7 µm. This means that the energy transfer for heating purposes does not affect the visual orientation of humans and animals.The use of OLEDs (OLED - organic light emitting diode = luminous thin-film component made of organic semiconducting materials) is to be considered equivalent with regard to the present invention.

[0044] In the context of the present invention, (IR) LEDs are understood to mean all radiation-emitting semiconductor components, LEDs, IR LEDs, IR OLEDs, and / or OLEDs. This includes both semiconductor components that emit radiation in the wavelength range > 0.7 µm, i.e., in the IR range, and semiconductor components that emit radiation in the wavelength range from 0.4 to 0.78 µm, i.e., in the visible light range.

[0045] For the present invention, it is clear that the radiant heater must comprise at least semiconductor components that emit radiation in the wavelength range > 0.7 µm. However, the radiant heater according to the invention can also contain semiconductor components that emit radiation in the visible light range, so that the radiant heater according to the invention can also fulfill an illumination function in addition to the heating function.

[0046] The radiation propagation characteristics of IR LEDs and pure thermal radiation from surfaces are significantly different. LEDs generally have a much more focused radiation pattern ("lossless lampshade"). This can further increase the efficiency of such a radiant heating system with IR LEDs, depending on the location and extent of the heating task.

[0047] The terms "operating device" or "power supply" are often used synonymously for the ballast provided by the invention. The ballast converts the electrical energy supplied from the general power grid into electrical energy with the parameters required (current, voltage) for the operation of (IR) LED modules.

[0048] This transformation process is associated with energy losses. Part of the supplied electrical energy is converted into heat energy, and the ballast dissipates this heat (heat loss). This negatively impacts the efficiency of a radiant heating system with (IR) LED modules, i.e., the ratio of the energy arriving at the specified heating location to the electrical energy used.

[0049] According to the invention, the heat loss from the ballast now at least partially benefits the actual heating task. This is achieved by the ballast becoming a component of the actual radiant heating system. It is integrated on top of, or at least only partially within, the heat sink, which partially encloses the (IR) LEDs and dissipates heat from the (IR) LEDs and the ballast. Due to the positioning of the ballast, at least one surface of the ballast is always facing the area to be heated, thus also emitting infrared radiation to it.

[0050] Furthermore, the integrated ballast is connected to the heat sink, at least by a positive fit, with excellent thermal conductivity. The heat sink absorbs heat from the ballast and then dissipates most of it toward the heating task, further improving the efficiency of the radiant heating system according to the invention. As with the (IR) LEDs, the rear thermal insulation minimizes heat dissipation from the ballast in an undesired direction.

[0051] The ballast surfaces facing the area to be heated advantageously have a high emission coefficient for thermal radiation, preferably greater than 0.9. This can be achieved, for example, through appropriate coatings. Furthermore, the ballast's geometry can be optimized to deliver the greatest possible amount of radiant energy toward the heating task and heat to the heat sink. A shallow depth (installation height) and consequently a larger length and width are more advantageous.

[0052] Depending on the application, it may also be advantageous for the radiant heater according to the invention to have a modular design. Both the semiconductor components and the ballast(s) can be designed as modules.

[0053] Each semiconductor component or (IR) LED module as a structural component combines one or more (IR) LEDs and fulfils at least one of the following tasks a) to f). a) electrically conductive connection of the (IR) LEDs in accordance with the designed technical parameters, b) electrical connectivity of the (IR) LEDs connected in this way, c) static fixation of the (IR) LEDs, d) ensuring proper heat dissipation, e) inclusion of optical or mechanical devices to influence the propagation of the electromagnetic radiation emitted by the (IR) LEDs, f) inclusion of design elements to improve the aesthetic appearance of the module.

[0054] An advantageous embodiment of the radiant heater according to the invention is when the ballast(s) integrated on or in the heat sink are designed such that the (IR) LED modules and the ballast(s) are produced in modules and then connected to each other at the installation site in a form-fitting, material-fitting, and / or force-fitting manner. This embodiment of the invention can offer advantages in production, during assembly, and / or in the event of repairs.

[0055] The modularity allows for a wide variety of combinations. The ballast with heat sink and thermal insulation can form a module alongside the (IR) LED modules. However, the heat sink for the ballast with thermal insulation can also form a module, in which case the ballast and the (IR) LED modules, as essential components of the radiant heating system according to the invention, complete it.

[0056] It is also possible to arrange a thermally insulating layer, which can also be designed as an air layer, between the ballast module(s) and the (IR) LED module(s). This is advantageous when the (IR) LEDs used and the ballast have different maximum permissible ambient temperatures as technical parameters. In this case, the thermal insulation significantly minimizes heat transfer by conduction between the two associated heat sinks. The thickness of the air layer and / or the thermal insulation is then preferably greater than approximately 3 mm.

[0057] The heat sink materials used according to the invention should exhibit the highest possible thermal conductivity and thermal diffusivity, such as copper, aluminum, and / or graphite. At the same time, the surface emitting thermal energy in the direction of radiation from the semiconductor components in the wavelength range > 0.7 µm should also exhibit the highest possible emission coefficient for thermal radiation. This can be achieved, for example, by coatings or coverings on the surface. Materials such as radiator paints can be used as such coatings or coverings.

[0058] The function of the heat sink - large-area heat absorption of the device elements of the radiant heater according to the invention, such as the (IR) LEDs and / or the ballast(s) and dissipation of the absorbed heat by thermal conduction and by convection and radiation essentially in the direction of the heating task - can be fulfilled in a further embodiment of the invention by a metal core circuit board.

[0059] A metal-core circuit board is a good alternative to a standard circuit board when the circuit board is subjected to greater mechanical stress, dimensional stability is required, and / or high heat flows from power components or (IR) LEDs must be dissipated. In the simplest case, it consists of the copper layer of the actual current-carrying conductor, typically in the µm range in thickness, an electrically insulating layer, also typically in the µm range, and the subsequent metal core. The material choice of this core is determined by the aforementioned tasks of static support and dimensional stability, as well as ensuring excellent heat dissipation. The core is therefore typically made of copper or aluminum in the mm range. Due to their thickness and the material's thermal conductivity, the copper layer (conductor) and the electrically insulating layer represent a completely negligible thermal resistance.

[0060] The metal-core circuit board used according to the invention is then also coated with highly effective thermal insulation, also facing the direction of the heating task. This minimizes heat dissipation to the environment on this side. The side facing the heating task (direction of radiation from the semiconductor components in the wavelength range > 0.7 µm) has a high emission coefficient for thermal radiation, preferably > 0.9, which can be achieved by applying a coating layer.

[0061] It is advantageous for the thermal insulation to be made of common mineral, inorganic, and organic insulating materials or insulation boards, such as rock wool, glass wool, calcium silicate, foamed plastics, foamed elastomers, vacuum insulation boards, plant or animal fibers, or recycled materials. It is also advantageous for the thermal insulation to have a low emission coefficient for thermal radiation on the side facing away from the heating task. This is usually achieved by aluminum lamination.

[0062] The thermal insulation is advantageously connected to the heat sink of the ballast and the (IR) LED modules in a form-fitting and / or force-fitting and / or material-fitting manner, unless a support structure is arranged in between.

[0063] Furthermore, it may be advantageous for the ballast(s) connected to the heat sink in a form-fitting, force-fitting, and / or material-fitting manner, in which at least one surface faces the heating task and thus contributes to the heating task with the released waste heat, to be provided with a cover for optical or functional reasons. This cover can, in turn, be connected to the ballast in a form-fitting, force-fitting, and / or material-fitting manner, whereby the waste heat is absorbed by the ballast through conduction and then dissipated by radiation and convection, preferably in the direction of the heating task, as in the arrangement without a cover.

[0064] A further minimization of the convective heat emission and thus of efficiency losses can be achieved in the solution according to the invention in that the radiant heater is provided with further device elements, advantageously in the form of structures, for blocking and / or obstructing the air flow over the surface of the radiant heater, which emits at least radiation of the semiconductor components in the wavelength range > 0.7 µm in the direction of the heating task.

[0065] In this case, structures for blocking and / or obstructing the air flow caused by free convection or for other reasons over the side facing the heating task can advantageously be present on the edge of the radiant heater on the surfaces which emit radiation in the wavelength range > 0.7 µm in the direction of the heating task, advantageously in the form of sheets or baffles.

[0066] In a further advantageous embodiment of the invention, the ballast(s), with or without a cover, is / are arranged on the surface of the radiant heater with a greater height difference of its surface in the direction of radiation emission of the semiconductor components, compared to the surface in the direction of radiation emission of the semiconductor components.

[0067] As a result, the ballast(s) themselves form a flow obstacle for free, forced or mixed heat dissipation by convection over the side of the radiant heater facing the heating task, whereby the lossy heat dissipation of the (IR) LED modules by convection is significantly reduced.

[0068] The raised arrangement of the ballast(s) can have a height difference of a few millimeters to approximately 10 cm from the surface of the (IR) LED modules. This prevents any free, forced, or mixed convective heat dissipation via the (IR) LED modules, further minimizes overall convective losses, increases the percentage of emitted thermal radiation relative to the supplied electrical energy, and thus further enhances the overall efficiency of the radiant heating system.

[0069] Likewise, other components such as permeable covers, optical lenses and / or beam guiding elements for radiation in the wavelength range > 0.7 µm may be present.

[0070] Typically, in residential and commercial construction or similar applications, heating and lighting tasks must be solved simultaneously. The required heating outputs generally differ by orders of magnitude from the lower connected loads required for the lighting task. The advantageous embodiments of the invention make it possible to equip one or more (IR) LED modules or even one or more radiant heating modules (see example 5) only with LEDs that emit electromagnetic radiation primarily in the visible wavelength range. This allows the module surfaces to be used for both tasks precisely as required according to a design calculation. At the same time, a uniform appearance in the room is maintained.

[0071] The invention is explained in more detail below using several examples.

[0072] Show Fig. 1 a schematic section through a radiant heater with (IR) LEDs and integrated ballast, with the ballast being arranged on the heat sink Fig. 2 a schematic section through a radiant heater with (IR) LEDs and integrated ballast, whereby the ballast is partially surrounded by the heat sink at least in a form-fitting manner Fig. 3 a schematic perspective projection view of a radiant heater with (IR) LEDs and integrated ballast Fig. 4 a schematic perspective projection view of a radiant heater with (IR) LEDs and integrated ballast, wherein the (IR) LEDs and a heat sink and thermal insulation, which together form an (IR) LED module, and the ballast and a heat sink and thermal insulation, which together form a module, are designed and combined as individual modules Fig. 5 a frame-shaped support structure Fig. 6 the view towards the heating task of the radiant heating module x with (IR) LED modules and two modules consisting of ballast and heat sink Fig. 7 a section through the radiant heating module x with (IR) LED modules and two modules consisting of ballast and heat sink along the section line A - A in Fig. 6 Example 1

[0073] With radiant heating according to Fig. 1 The heat sink 2 is realized by a metal-core circuit board. Copper is used as the material for the metal core. The thickness of the metal core is approximately 1.5 mm, the thickness of the conductor layer (also made of copper) is approximately 35 µm, and the thickness of the insulating layer between them is approximately 60 µm.

[0074] For the thermal insulation 3 on the side facing away from the heating task, a foamed, high-temperature-resistant elastomer (thermal conductivity 0.045 W / (mK)) with a layer thickness of 0.025 m is used, which is provided with an aluminum lamination on the side facing away from the heating task.

[0075] The height difference 8 of approximately 0.04 m between the ballast 4 and the (IR) LEDs 1 on the heat sink 2 hinders possible free, forced or mixed convective heat dissipation over the surface of the heat sink 2 with the (IR) LEDs 1.

[0076] This further minimizes convective losses, increases the percentage of emitted heat radiation in relation to the supplied electrical energy and thus further increases the overall efficiency of the LED radiant heater. Example 2

[0077] In Fig. 2 a schematic section through a radiant heater with (IR) LEDs 1 and integrated ballast 4 can be seen, wherein the ballast 4 is partially surrounded by the heat sink 2, at least in a form-fitting manner.

[0078] A metal-core circuit board is also used as heat sink 2, but unlike Example 1, it has an aluminum metal core with a layer thickness of 3 mm. Furthermore, the dimensions of the ballast 4 have been changed compared to Example 1 in that the height is now approximately 0.02 m and the width has been doubled. The ballast 4 is surrounded by a 2 mm layer of heat sink 2 on its sides. The structure and properties of the thermal insulation 3 correspond to those of Example 1.

[0079] By using the heat loss from ballast 4 for the heating task, the overall heat output of the radiant heater is increased. Example 3

[0080] According to Fig. 3 A radiant heater can be seen which has (IR) LEDs 1 which are electrically connected to one another by a very thin (thickness approx. 93 µm) and flexible circuit board with the carrier material polyimide, which ensures the electrical connection of the (IR) LEDs, and which are attached to a heat sink 2 made of 3 mm aluminum. The circuit board and the heat sink 2 are separated from one another by an electrically insulating layer with a layer thickness in the µm range. Due to the combination of the material property of thermal conductivity and the selected material thickness, the circuit board material and the electrically insulating layer represent a negligible thermal resistance. The ballast 4 is arranged on the same heat sink 2 as the (IR) LEDs 1.The printed circuit board material, the surfaces of the heat sink 2 facing the heating task without further covering, and the surfaces of the ballast 4 facing the heating task have a surface coating that has a high emission coefficient for thermal radiation of 0.91.

[0081] The structure and properties of thermal insulation 3 correspond to those of Example 1. Example 4

[0082] The Fig. 4 shows a schematic perspective projection view of a radiant heater, wherein the (IR) LEDs 1, a heat sink 2, and the thermal insulation 3 are implemented as an (IR) LED module, and the ballast 4, a heat sink 2, and the thermal insulation 3 are implemented as another single module and combined in the radiant heater. This combination can be implemented in a form-fitting and / or material-fitting and / or force-fitting manner. In the present case, it is implemented in a form-fitting manner.

[0083] At the junction between the modules, a heat-insulating layer 6 made of a foamed, high-temperature-resistant elastomer (thermal conductivity 0.045 W / (mK)) with a thickness of 6 mm is arranged.

[0084] The presence of a thermally insulating layer 6 is necessary because the (IR) LEDs 1 and the ballast 4 used have different maximum permissible ambient temperatures as technical parameters. In this case, the thermally insulating layer 6 significantly minimizes heat transfer by conduction between the two associated heat sinks 2.

[0085] The structure of the (IR) LED modules with respect to heat sink 2 and circuit board corresponds to the structure, dimensions, and properties in Example 3. The heat sink 2 of the ballast 4 is made of 3 mm thick aluminum. The surfaces of this heat sink 2 and the ballast 4 facing the heating task have a surface coating with a high emission coefficient for thermal radiation of 0.91. The structure and properties of the respective rear thermal insulation 3 correspond to those of Example 1.

[0086] Furthermore, a plate 5 is provided to reduce airflow caused by free convection or other reasons above the side facing the heating task. The plate protrudes approximately 0.04 m above the side of the (IR) LED modules facing the heating task. Example 5

[0087] A radiant heating system can be Fig. 5 bis Fig.7 be arranged on a frame-shaped support structure 7.

[0088] IR LED modules are used, consisting of IR LEDs 1 and a heat sink 2. The heat sink 2 in the IR LED modules is performed by a metal core circuit board. Copper or aluminum is used as the metal core material. The thickness of the metal core is approximately 1 to 3 mm.

[0089] The heat sink 2 associated with the ballast 4 consists of an aluminum plate approximately 2 to 3 mm thick.

[0090] IR LED modules and modules consisting of a ballast 4 and a heat sink 2 are mounted on the support structure 7 from the side facing the heating task for easier installation and possible repair. The support structure 7 provides static support for the entire IR LED radiant heater and also accommodates the highly effective, continuous thermal insulation 3 to minimize heat dissipation from the entire radiant heater against the direction of the heating task. The support structure 7 is designed as a frame with individual struts for securing the IR LED modules and the modules consisting of a ballast 4 and a heat sink 2. A feature of the support structure is its low specific weight. This can be achieved, for example, by using aluminum or glass-fiber-reinforced plastic (GRP).

[0091] Within the support structure 7, according to Fig. 6Six IR LED modules are arranged, each having IR LEDs 1 and a heat sink 2. Furthermore, two modules, each with a ballast 4 and a heat sink 2, are arranged in the support structure 7. Together with the continuous thermal insulation 3 inserted into the support structure 7, the modules form a radiant heater with the support structure 7.

[0092] A heat-insulating layer 6 in the form of an air layer is formed between the IR LED modules and the modules consisting of the ballasts 4 and heat sink 2. As a result, the heat sink 2 belonging to the IR LED modules and the heat sink 2 assigned to the ballast 4 have different temperatures. This is necessary because the ballasts 4 and IR LEDs 1 used have different permissible ambient temperatures as technical parameters. The necessary heat sink sizes are designed using appropriate thermal engineering calculations.

[0093] All heat sink surfaces 2 and the surfaces of the ballasts 4 facing the heating task have a high emission coefficient for thermal radiation of 0.91 due to a lacquer coating.

[0094] Due to the selection of the individual components of the described radiant heater with IR LEDs 1, it has a defined electrical connection load and a defined radiant output as a function of the room temperature. To cover the entire heating load of the specific heating task, several radiant heaters of the specific design are required. A single radiant heater is then referred to as radiant heater module x, which essentially consists of a) IR LED modules, b) a module consisting of a ballast 4 and a heat sink 2, c) a support structure 7, and d) thermal insulation 3.

[0095] The radiant heating module x can be combined with other modules (schematically shown modules x -1 or x + 1) so that the heating output is increased and a desired heating output is achieved.

[0096] The ballasts 4 are arranged on a single radiant heating module in such a way that they themselves represent a flow obstacle for free, forced or mixed heat dissipation by convection over the side facing the heating task and thus significantly reduce the lossy heat dissipation of the IR LED modules by convection.

[0097] The lateral and raised arrangement of the ballasts 4, with a height difference 8 of approximately 5 cm, hinders any possible free, forced, or mixed convective heat dissipation of the (IR) LED modules. This further minimizes convective losses, increases the percentage of emitted thermal radiation relative to the supplied electrical energy, and thus further enhances the overall efficiency of the radiant heating system.

[0098] A total of 162 IR LEDs 1 are arranged on all IR LED modules for a radiant heating module x. Each IR LED 1 is located in the center of a proportional square heat sink surface 2 (metal core circuit board) with an edge length of 0.0625 m and has an electrical power consumption of 3.5 W at an ambient temperature of 10 °C. The layer thickness of the thermal insulation 3 made of rock wool is 0.03 m. Furthermore, the thermal insulation 3 has a thermal conductivity coefficient of 0.04 W / (mK) and an aluminum lamination on the side facing away from the heating task (emission coefficient for thermal radiation approximately 0.1).

[0099] The connected load of all IR LED modules in a radiant heating module is approximately 567 W. These are supplied by two ballasts 4, which together have a power consumption of approximately 600 W. Approximately 80% of the conversion losses of approximately 33 W are radiated toward the heating task. This represents approximately 4.5% of the electrical energy used.

[0100] In total, a radiant heating system with many radiant heating modules according to the described structure emits approximately 85 to 87% of the electrical energy used in the form of infrared radiation in the direction of the heating task.

[0101] In the specific application, 75 of the described radiant heating modules are implemented and represent a total radiant heating system with semiconductor components and integrated ballasts with a connected load of 45 kW. Approximately 39 kW of this is emitted as infrared radiation in the direction of the heating task.

[0102] To solve the lighting task in this specific application, four additional radiant heating modules are fully equipped with LEDs 1, which emit radiation in a wavelength range of 0.4 to 0.78 µm, thus achieving the required calculated light output. These modules are thus fully light modules. Inserted into the radiant heating strip of 45 radiant heating modules, a uniform appearance is achieved in the room. List of reference symbols

[0103] 1 -(IR-)LED 2 -Heat sink 3 -Heat insulation 4 -Ballast 5 -Sheet metal, which as a further device element forms an edge to minimize the air flow caused by free convection or other reasons over the surface facing the heating task 6 -Heat-insulating layer 7 -Frame-shaped support structure 8 -Height difference between the surface of the ballast and the surface of the (IR-)LED module

Claims

1. Radiant heater, wherein at least one semiconductor component (1) which emits at least radiation in the wavelength range > 0.7 µm is partly surrounded by a heat sink (2), wherein at least one surface of the semiconductor component (1) for emitting radiation in the wavelength range > 0.7 µm is not covered by the heat sink (2), and wherein the heat sink (2) has at least one surface in the direction of the radiation emission of the semiconductor components (1) in the wavelength range > 0.7 µm, and the heat sink (2), at least in the opposite direction to the radiation emission of the semiconductor components (1) in the wavelength range > 0.7 µm, is arranged at least partly in at least positively locking contact with a thermal insulation (3), characterized in that furthermore at least one ballast (4) for converting the electrical energy for the operating mode of the semiconductor components (1) is present which is positioned with at least one surface on the surface of or partly in the heat sink (2) and at least one surface of the ballast (4) faces in the direction of the radiation emission of the semiconductor components (1) in the wavelength range > 0.7 µm, and further device elements can be present.

2. Radiant heater according to Claim 1, wherein IR LEDs and / or IR OLEDs are present as semiconductor component (1) .

3. Radiant heater according to Claim 1, wherein one or more semiconductor components (1), such as LEDs and / or OLEDs, which emit radiation starting from the wavelength range > 0.4 µm can be present besides one or more semiconductor components (1) which emit radiation in the wavelength range > 0.7 µm.

4. Radiant heater according to Claim 3, wherein the radiant heater comprises semiconductor components (1) which emit radiation in the wavelength range > 0.7 µm and semiconductor components (1) which emit radiation in the wavelength range of 0.4 to 0.78 µm.

5. Radiant heater according to Claim 1, wherein the heat sink (2) consists of copper, aluminium and / or graphite or is embodied as a metal-core printed circuit board.

6. Radiant heater according to Claim 1, wherein the thermal insulation (3) consists of mineral, inorganic and organic insulants or insulating plates, advantageously of rock wool, glass wool, calcium silicate, foamed plastics, foamed elastomers, vacuum insulating plates, plant or animal fibres or recycling material.

7. Radiant heater according to Claim 6, wherein the thermal insulation (3) has a low emission coefficient for thermal radiation on the surface of the side facing away from the heating task, said low emission coefficient advantageously being realized by an aluminium lamination.

8. Radiant heater according to Claim 1, wherein the semiconductor component (1) and / or the at least one ballast (4) are / is not covered by the heat sink (2) only at the surface for emitting radiation of the semiconductor components (1) in the wavelength range > 0.7 µm.

9. Radiant heater according to Claim 1, wherein the heat sink (2) is arranged in positively locking contact with an insulation (3) at all surfaces, apart from at the surfaces at which the semiconductor components (1) and / or the ballast (4) are / is arranged and apart from at the surface in the direction of the radiation emission of the semiconductor components (1) in the wavelength range > 0.7 µm.

10. Radiant heater according to Claim 1, wherein structures (5) for preventing and / or impeding the air flow over the surface of the radiant heater which emits at least radiation of the semiconductor components (1) in the wavelength range > 0.7 µm are present as further device elements.

11. Radiant heater according to Claim 10, wherein metal sheets or baffle plates (5) are present as structures (5) for preventing and / or impeding the air flow over the surface of the radiant heater which emits at least radiation of the semiconductor components (1) in the wavelength range > 0.7 µm.

12. Radiant heater according to Claim 10, wherein one or more ballasts (4) are present as structures (5) for preventing and / or impeding the air flow over the surface of the radiant heater which emits at least radiation of the semiconductor components (1) in the wavelength range > 0.7 µm, said one or more ballasts having a larger height difference (8) of their surface in the direction of the radiation emission of the semiconductor components (1) by comparison with the surface in the direction of the radiation emission of the semiconductor components (1).

13. Radiant heater according to Claim 1, wherein for radiation in the wavelength range > 0.7 µm transmissive covers, optical lenses and / or beam guiding elements are present as further device elements.

14. Radiant heater according to Claim 1, wherein the semiconductor components (1) and / or the ballasts (4) are arranged on and / or in and / or with the heat sink (2) in a modular design, and the modules can be removed individually from the radiant heater.

15. Radiant heater according to Claim 1, wherein one or more thermally insulating layers (6) arranged between semiconductor components (1) and / or ballast (4) and / or heat sink (2), in each case as individual elements or as modules, are present as further device elements.