Surface radiator, device having surface radiator and use of surface radiator

Abstract

The invention relates to a surface radiator (100) having a light-emitting semiconductor component (2) and a housing (1). The housing (1) has at least one cooling channel (10, 11) for a coolant, which cooling channel forms part of a fluid path (a) extending from an inflow opening (3) to a return opening (4) of the housing (1). An emission window (5) is arranged on the housing, covers the light-emitting semiconductor component (2) and defines a front side of the surface radiator (100) and is transparent to the use radiation (S) that can be emitted by the semiconductor component (2). The housing (1) provides the at least one light-emitting semiconductor component (2) with a fastening surface (12) spaced apart from the emission window (5). The arrangement of the emission window (5) on the housing (1) is fluid-tight, and the housing (1), the light-emitting semiconductor component (2) and the emission window (5) define an emission chamber (6). The fluid path (a) is defined by i) at least one first cooling channel (10) extending through the housing (1) from an inflow opening (3) to a mouth opening (13), and ii) a firing chamber (6), and iii) at least one second cooling channel (11) extending through the housing (1) from an outflow opening (14) to a return opening (4). The coolant (K) is an electrically insulating liquid which is transparent to the use radiation (S).

Description

Technical Field

[0001] The invention relates to a surface radiator having a light-emitting semiconductor component and a device for lighting, photochemical reaction or disinfection equipped with such a surface radiator, as well as a use of such a surface radiator for photochemical reaction or disinfection. Background Art

[0002] It is known from the prior art to use surface radiators with directional light radiation to achieve uniform illumination of a surface. The surface radiator therefore has a one-sided radiation characteristic, wherein the radiation angle can vary. Due to the significantly reduced energy consumption, surface radiators with light-emitting semiconductor components, such as light-emitting diodes (LEDs), are also increasingly used to radiate light on large surfaces. Even at the spontaneous full luminous flux, LEDs have a high service life and a high switching resistance. Although LEDs are not heat sinks, the high temperatures that occur during operation can significantly shorten the service life of the LEDs, depending on the arrangement and properties of the LEDs. In order to avoid this adverse effect, the LEDs are usually not operated at the rated power, but at a power lower than the rated power, and in order to obtain the required amount of light, the number of LEDs used increases.

[0003] To form a surface radiator, the LEDs are arranged with their housing frames on a substantially flat, usually rectangular carrier surface behind an emission window and can be surrounded by a reflector frame to adjust the radiation characteristics. In the case of surface radiators with a very large number of LEDs, these can be fixed in groups on corresponding circuit boards, on which conductor tracks are provided for electrical contacting of the LEDs and, if necessary, a ballast (LED driver) for control. The conductor tracks usually extend to the edge of the circuit board in order to make electrical connections there. Disadvantageously, the heat generated during operation cannot be sufficiently dissipated from the circuit board.

[0004] Therefore, EP 2701473 A2 proposes a circuit board for LED surface radiators, which provides a planar conductor track segment that forms a relatively large interface with the surrounding area of ​​the circuit board. The waste heat generated by the LED will be dissipated from the circuit board to the environment through the planar conductor track segment.

[0005] In order to significantly improve the heat dissipation, metal housings are used, mainly made of aluminum. For example, DE 202011050253 U1 discloses a lighting device with a plurality of LEDs, which are arranged on a carrier unit configured as a printed circuit board. The lighting device also includes an H-shaped aluminum profile body with two parts, wherein the carrier unit with the LEDs is arranged on a first part of the profile body. A translucent polymer housing surrounds the carrier unit with the LEDs and the first part. The second part of the profile body protruding from the polymer housing serves to transfer heat to the housing.

[0006] In industrial applications of high-power diodes, more efficient heat dissipation is required to preserve the service life of the LEDs, which operate at high currents with high light output or high radiant intensity.

[0007] WO2020 / 148289A1 describes a planar light source with LEDs for curing printing ink or varnish, wherein at least one light-emitting semiconductor component (as an LED module with an associated circuit board) is arranged on a carrier plate. The light source also has a distributor element configured as a housing, on which an emission window superimposed on at least one LED module is arranged. In addition, the housing distributor element has a cooling channel, which is connected to a connector for the inflow and return of a cooling fluid via a connecting element. Multiple carrier plates with LED modules can be arranged on the housing distributor element, wherein the surface of each carrier plate facing away from the LED module is configured as a cooling surface, which is arranged on the distributor element in a sealed manner. Therefore, the cooling surface partially defines a fluid path that is connected to the cooling channel in the distributor element via a channel branch. Summary of the invention

[0008] Starting from this prior art, the object of the present invention is to provide a surface radiator which is improved with regard to heat dissipation and thermal decoupling of light-emitting semiconductor components.

[0009] This object is achieved by a surface radiator having the features of claim 1 .

[0010] A further object of providing a device for lighting, performing photochemical reactions or disinfection is achieved by a device having the features of independent claim 13 which is improved with regard to heat dissipation and thermal decoupling of light-emitting semiconductor components of a surface radiator.

[0011] By using a device having the features of independent claim 15 , a use of a surface radiator is disclosed which is improved with regard to heat dissipation and thermal decoupling of light-emitting semiconductor components.

[0012] Developments are set forth in the respective dependent claims.

[0013] According to a first embodiment, the surface radiator according to the present invention has at least one light-emitting semiconductor component and a housing having at least one cooling channel for a coolant. In this case, the surface radiator generally comprises a plurality of LEDs, which are arranged side by side at a uniform distance on a substantially flat surface for unilateral directional light radiation. The cooling channel forms at least a portion of a fluid path extending from an inlet opening of the coolant to a return opening of the coolant. The inlet opening and the return opening are formed on the housing and are preferably used to connect to a coolant circuit. An emission window is provided on the housing, which defines the front side of the surface radiator, on which unilateral directional light radiation occurs. The "emission window" here is understood to be a plate or disk made of a material transparent to the use of radiation emitted by at least one light-emitting semiconductor component, the use of radiation being defined by electromagnetic radiation of at least one predetermined wavelength or at least one predetermined wavelength range, depending on the intended use of the surface radiator for lighting, photochemical reactions or disinfection. "Transparent" here means that the emission window using radiation has a transmittance of at least 75%. The size of the emission window and its arrangement on the housing correspond to the arrangement of one LED or a plurality of LEDs, so that the emission window covers at least one light-emitting semiconductor component on the surface.

[0014] According to the invention, the housing itself provides a fastening surface for at least one light-emitting semiconductor component spaced apart from the emission window, without the need for an additional carrier structure as in the prior art, wherein the fastening surface for arranging the LED corresponds to the emission window. The arrangement of the emission window on the housing is fluid-tight, so that a sealed emission chamber is defined by the housing, the semiconductor component and the emission window. The fluid path for cooling the LED is then defined by,

[0015] i) at least one first cooling channel extending from the inlet opening through the housing to one or more mouth openings formed on a first side adjacent the fastening surface and opening into the firing chamber, and

[0016] ii) a firing chamber extending from a mouth opening to one or more outflow openings, the one or more outflow openings being formed on a fastening surface on a second side of the housing adjacent to the first side, such that the fastening surface is located between the mouth opening and the outflow openings and the firing chamber is completely filled with coolant, and

[0017] iii) at least one second cooling channel, the at least one second cooling channel extending from the outflow opening through the housing to the return opening.

[0018] Since according to the invention the coolant thus fills the emission chamber and is in direct contact with the LED in order to more effectively dissipate the heat generated by the LED during operation, according to the invention the coolant is an electrically insulating liquid which is transparent to the use radiation emitted by the light-emitting semiconductor component and which, due to the specific heat capacity, density and thermal conductivity, provides a better heat transfer than a gaseous cooling medium or air. In this case, transparency is understood to be relative to the path length defined by the distance between the LED and the emission window, which path length is at least 75%. Advantageously, by flooding the emission chamber with a liquid coolant, which is supplied from the first cooling channel through the mouth opening and discharged into the second cooling channel through the outflow opening, heat can be absorbed not only from the LED but also, optionally, from the environment, which heat can be released from outside the surface radiator, thereby avoiding heat accumulation between the LED and the emission window, keeping the temperature of the LED constant and achieving thermal decoupling of the surface radiator from the environment. Another advantage of flooding the emission chamber with a liquid coolant is that the formation of condensed water is avoided in the case of large temperature gradients relative to the environment or the irradiated surface.

[0019] Preferably, a circuit design of the coolant can be provided, in which the coolant heated in the surface radiator is guided in a circuit in order to release the absorbed heat again outside the emission chamber. Flooding the emission chamber with liquid coolant also advantageously ensures that near-field reflections between the LED and the emission window are avoided and prevents the presence of volatile organic hydrocarbon compounds (VOCs) in the emission chamber that could damage the LED. Compared with the use of inert gases such as nitrogen, the advantage here is that accelerated aging of the primary optics of the LED is avoided. This is because VOCs ("volatile organic compounds") are particularly present in chemical plants, which penetrate into the primary optics, which are usually designed as silicone lenses, making them turbid and thus reducing the light output. Since the primary optics according to the invention are no longer exposed to any gas-containing atmosphere, but are shielded by the coolant, the aging process is significantly slowed down. In order to completely avoid the limitation of the light output due to the aging process of the primary optics, in the surface radiator according to the invention, there is advantageously the possibility that protective primary optics, such as silicon lenses, can be omitted in the LED, because the liquid coolant already fully protects the semiconductor chip of the LED from environmental influences.

[0020] The surface radiator according to the invention is thus not only improved in terms of cooling of the LED and thermal decoupling from the environment, but also protects the LED from harmful substances. Furthermore, the surface radiator according to the invention particularly advantageously provides an increased total light or radiated power relative to lamps according to the prior art, since the photon decoupling efficiency at the phase boundary of the diode surface relative to the coolant in the emission chamber is increased due to the liquid coolant, and the reflection at the phase boundary between the coolant present in the emission chamber and the emission window is reduced.

[0021] In this case, “use radiation” is understood to be electromagnetic radiation of a specific wavelength or wavelength range which is suitable for the intended use of the surface radiator, for example lighting, carrying out a photochemical reaction or disinfection.

[0022] The light-emitting semiconductor component can be a light-emitting diode or preferably an LED module, which consists of at least one LED and a circuit board with conductor tracks for electrically connecting the at least one LED. In this case, the circuit board does not correspond to a carrier structure of the prior art: there are also used LED modules consisting of at least one LED and a circuit board, wherein the module is fixed to a carrier structure, for example an H-shaped carrier unit or a carrier plate with a cooling surface, via the circuit board, and the carrier structure is arranged on a housing.

[0023] In this case, LED is understood to be all light-emitting diodes that emit electromagnetic radiation in the infrared, visible or ultraviolet wavelength range, including organic light-emitting diodes (OLED). In addition, LEDs can have an emission spectrum with a combination of components in the infrared, visible and / or ultraviolet wavelength range. In order to adapt the radiation emitted by the LED to the intended purpose, the LED is usually doped differently. For example, diamond, aluminum nitride, aluminum gallium nitride or aluminum gallium indium nitride can be used as a dopant for emitting UV radiation. According to another embodiment of the surface radiator according to the present invention, the housing can have a rear side facing away from the front side and is defined by the side between the front side and the rear side. The inflow opening and the return opening of the fluid path can be arranged together on one side, or arranged together on the rear side, or arranged separately on different sides, or arranged separately on one side and the rear side in each case. The arrangement of the inflow opening and the return opening on the rear side and / or the side of the housing can be selected according to the installation environment of the surface radiator in a superordinate device for lighting, in particular for performing photochemical reactions or for disinfection. The housing can also be designed for arranging the surface radiator in such a superordinate device, since the housing can have, for example, one or more mounting elements, such as fastening holes, tabs or collars.

[0024] According to another advantageous embodiment of the surface radiator of the present invention, the mouth opening is formed on the side of the fastening surface facing away from the inflow opening, that is, away from the inflow opening. The first cooling channel extends at least partially through the housing in a plane parallel to the mounting surface so as to lead to the emission chamber in a region away from the inflow opening. Since the first cooling channel extends through the housing below the fastening surface, the heat generated by the LED and absorbed by the housing via the fastening surface can be released from the housing to the coolant that has been supplied through the two channels of the first cooling channel. The housing is preferably made of a thermally conductive material, particularly preferably aluminum. In this way, the temperature of the housing can also be kept constant, so that the heat generated by the LED can be dissipated not only on the front side by direct contact between the LED and the coolant, but also on the rear side by the housing. At least one outflow opening can preferably be formed on the side of the fastening surface close to or facing the return opening, so that the heated coolant is guided to the return opening through the second cooling channel and can be kept as short as possible.

[0025] Depending on the number and / or power of the LEDs, in particular in the case of a greater number and / or higher power of the LEDs, in another embodiment of the surface radiator according to the invention, it can be provided that the inflow opening is fluidly connected to a distributor channel portion close to the inflow opening, from which a plurality of first cooling channels extend through the housing and parallel to the fastening surface to the corresponding mouth openings. The second cooling channel can then extend from the collecting channel portion connected to the plurality of outflow openings to the return opening. Optionally, the first cooling channel can extend from the inflow opening to the distributor channel portion, which is away from the inflow opening and on which a plurality of mouth openings are formed, wherein here, the second cooling channel also extends from the collecting channel portion connected to the plurality of outflow openings to the return opening. In a possible, less preferred alternative, the housing can have a plurality of first cooling channels, the first cooling channel having a corresponding plurality of allocated inflow openings and outflow openings, and a plurality of second cooling channels, the first cooling channel having a corresponding plurality of allocated outflow openings and return openings.

[0026] According to a further embodiment, the surface radiator according to the invention can have a holding frame which is preferably detachably arranged on the housing for holding the emission window and is configured corresponding to the window frame in such a way that the light opening provided through the emission window for the at least one light-emitting semiconductor component is not covered or is free. In order to seal the arrangement of holding frame and emission window on the housing, a circumferential seal can be arranged in each case between holding frame and emission window and between emission window and housing (for example, by means of sealing cords in corresponding sealing grooves in holding frame and housing).

[0027] As an alternative to fastening the emission window by means of a retaining frame, in another embodiment the emission window can be fastened to the housing by means of an adhesive layer which simultaneously provides a seal. In this case, an almost unlimited design of the surface radiator can advantageously be provided, which can be particularly suitable for integration into a superordinate device. Furthermore, embodiments are conceivable in which both arrangements of the adhesive layer of the emission window and the retaining frame are combined to the housing, for example, if the emission window is fixed in a sealing manner by means of an adhesive layer in a retaining frame, the retaining frame can be detachably arranged on the housing, so that only one circumferential seal is required to seal the retaining frame or the emission window to the housing.

[0028] Another embodiment of the surface radiator according to the invention relates to the fact that the housing body has at least one fastening shoulder on the front side, which fastening shoulder surrounds the fastening surface as a stepped circumference of the edge, wherein the first fastening shoulder is configured to receive the emission window, i.e. serves as a support for the emission window. The distance of the electromagnetic radiation through the coolant is thus defined by the height of the emission chamber, the distance of the first fastening shoulder, where the emission window is located, from the fastening surface. An embodiment can be provided with a second fastening shoulder, which surrounds the first fastening shoulder as a stepped circumferential edge, for arranging a holding frame for fastening the emission window to the housing.

[0029] In another embodiment of the surface radiator according to the present invention, a connection chamber can be formed in the housing on the front side close to the fastening surface, the connection chamber leading to the emission chamber for receiving electrical connection elements for the LED and filled with a coolant like the emission chamber. In addition, a connection opening is formed on the housing, wherein the arrangement of the connection opening on one of the side or rear sides of the housing can be selected according to the installation environment, such as the arrangement of the inflow opening and the return opening. As an electrical connection element for connecting to a power source outside the housing, at least one connection line for connecting at least one light-emitting semiconductor component extends at least into the connection chamber and optionally extends to or through the connection opening.

[0030] In addition, according to another embodiment, the surface radiator according to the present invention can have a plurality of light-emitting semiconductor components, in particular a plurality of LEDs arranged on a circuit board, if necessary, arranged on a plurality of circuit boards, by which the light-emitting semiconductor components are fastened to the fastening surface of the housing. In this case, on the circuit board, on one side close to the connection chamber, a pair of corresponding connection contacts for a row of light-emitting semiconductor components are formed on the circuit board, wherein each connection contact is conductively connected to a corresponding connection line. Here, a "row" of LEDs means a predetermined number of LEDs on the circuit board, which can preferably be arranged in a straight line along the length of the circuit board, but can also be arranged in different patterns, such as zigzags, if necessary. The surface radiator can include a circuit board with a row of LEDs, preferably with several parallel rows of LEDs. By arranging the connection contacts on one side of the connection chamber, the length of the connection line can be minimized, and the line can be avoided from passing through the emission chamber, as a result of which not only the shadow of the LED can be prevented, but also the wire sheath material can be protected, for example, from ultraviolet radiation. The conductive connection of the connection wire to the connection contact can be, for example, soldered to avoid insulation resistance caused by the coolant.

[0031] The ballast or LED driver required for operating the LED can be arranged on the circuit board between the connection contacts and the LED. However, in order to minimize the heat input of the ballast to the LED, according to another embodiment of the surface radiator according to the invention, it can be preferably provided that the ballast or the light-emitting semiconductor component is arranged in the connection chamber and connected to one or more connecting lines. In this case, the heat generated by the ballast is not transferred to the LED via the circuit board, but is transferred to the housing surrounding the connection chamber via the coolant and / or is taken away from the emission chamber together with the coolant. In addition, an alternative variant can provide that the ballast is arranged outside the housing and can be connected to one or more connecting lines extending through the connection chamber.

[0032] In a preferred embodiment, the connecting opening may be connected to the connecting chamber via a passage opening, wherein a cross-sectional area of ​​the passage opening is smaller than a cross-sectional area of ​​the connecting opening to facilitate sealing of the connecting opening relative to the connecting chamber filled with the coolant.

[0033] In this case, the passage opening can have a cross-sectional shape deviating from a circle, for example a polygonal shape, or can be configured, for example, in two planes, in order to prevent a rotational arrangement of a correspondingly shaped connecting element, for example a connecting plug connected to a connecting line or an adapter element through which a connecting line extends.

[0034] Therefore, in another embodiment for electrical connection, the surface radiator according to the invention can provide that at least one connecting wire extends from the connection chamber through the passage opening at least partially into the connection opening, or the surface radiator has a connection plug, to which at least one connecting wire (optionally via a ballast) is connected, wherein the connection plug at least partially extends into the connection opening and optionally also into the passage opening leading to the connection chamber. In order to avoid leakage through the insulating sheath of the connecting wire or the connecting plug, the arrangement of the connecting plug (or the connecting wire) in the connection opening (and / or the passage opening leading to the connection chamber) can be sealed by potting or a solder block.

[0035] Furthermore, according to an embodiment of the surface radiator according to the present invention, the surface radiator may have an inflow connection element connected to the inflow opening to connect the coolant inflow line. The surface radiator also has a return connection element connected to the return opening to connect the coolant return line. In this case, the connection of the inflow connection element to the inflow opening and / or the connection of the return connection element to the return opening is potted or soldered to prevent leakage.

[0036] The device according to the invention for lighting, performing photochemical reactions or disinfecting has, in one embodiment according to the invention, at least one surface radiator having at least one light-emitting semiconductor component, the emission spectrum of which provides corresponding use radiation for lighting, performing photochemical reactions or disinfecting.

[0037] According to another embodiment of the device for lighting, performing a photochemical reaction or disinfecting according to the invention, the device has a housing. This includes not only the wall that completely surrounds the reaction chamber, but also a holder in a more general sense. The housing thus at least partially surrounds the lighting chamber, the reaction chamber or the disinfection chamber and has at least one mounting position for at least one surface radiator. The housing of the surface radiator preferably has at least one mounting element for being arranged at a predetermined mounting position in the device.

[0038] The inventive use of the surface radiator according to the invention is lighting, carrying out photochemical reactions or disinfection, wherein at least one light-emitting semiconductor component of the surface radiator has an emission spectrum which provides suitable use radiation for lighting, carrying out photochemical reactions or disinfection. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Further embodiments and some advantages associated with these and further embodiments will become clear and more easily understood through the detailed description below with reference to the accompanying drawings. Substantially the same or similar objects or parts thereof may have the same reference numerals. The accompanying drawings are only schematic diagrams of embodiments of the invention.

[0040] In the attached picture:

[0041] Figure 1 is a perspective view of a surface radiator according to an embodiment of the present invention;

[0042] Figure 2 is based on Figure 1 A front view of the surface radiator of the present invention, with section lines AA, CC, DD, EE, FF;

[0043] Figure 3 yes Figure 2 A cross-sectional view of the surface radiator along the section line AA;

[0044] Figure 4 yes Figure 2 A cross-sectional view of a surface radiator along section line CC;

[0045] Figure 5 yes Figure 2 A longitudinal section of the surface radiator along the section line DD;

[0046] Figure 6 is based on Figure 5 A longitudinal sectional view showing the housing, emission window and holding frame of the surface radiator in an assembled state;

[0047] Figure 7 yes Figure 2 A longitudinal section of the surface radiator along the section line EE;

[0048] Figure 8 yes Figure 2 A longitudinal section of the surface radiator along the section line FF;

[0049] Fig. 9 is a schematic perspective view of a housing of a surface radiator according to the present invention, wherein a fluid path a is shown;

[0050] Fig.10 A front view of a surface radiator according to an embodiment of the present invention with electrical connection elements is shown;

[0051] Fig.11 is a schematic longitudinal section through a surface radiator according to another embodiment of the present invention;

[0052] Fig.12 is a schematic front view of a surface radiator having a distributor channel near a mouth opening according to another embodiment of the present invention;

[0053] Fig.13 is a schematic front view of a surface radiator having a distributor channel away from a mouth opening according to another embodiment of the present invention;

[0054] Fig.14 is a schematic front view of a surface radiator having a curved first cooling channel according to another embodiment of the present invention;

[0055] Fig.15 is a schematic cross-sectional view through an LED having a primary optics which can be used as a light-emitting semiconductor component in a surface radiator implemented according to the invention;

[0056] Fig.16 is a schematic cross-sectional view through an LED without primary optics, which LED can be used as a light-emitting semiconductor component in a surface radiator according to a further embodiment;

[0057] Fig.17 is a schematic side view of a device having a surface radiator for performing a photochemical reaction according to an embodiment of the present invention;

[0058] Fig.18 is a schematic side view of a device having a surface radiator for disinfection according to another embodiment of the present invention. DETAILED DESCRIPTION

[0059] The present invention relates to an LED surface radiator, which is mainly used as a high-power radiator for industrial purposes, for example as a surface radiator in a device for disinfecting surfaces or performing photochemical reactions. For this purpose, the surface radiator can be installed, for example, in a holder above the surface to be disinfected, or in a wall element of a photoreactor, which wall element can also be a reactor cover. In addition, the LED surface radiator according to the present invention can also be constructed for lighting purposes or as a thermal radiator, which as a high-power radiator also requires effective heat dissipation. Therefore, the present invention also relates to any device for lighting, and optionally a device for heat treatment, photochemical reaction or disinfection, which has a surface radiator in an embodiment according to the present invention, and the use of the surface radiator according to the present invention, in particular for lighting, but also optionally for heat treatment, photochemical reaction or general disinfection.

[0060] exist Figures 1 to 8 2 , the structure of a surface radiator 100 according to the present invention is explained, which has a plurality of LEDs 2 arranged on a surface and a housing 1 . Fig. 9 and 11 The simplified, almost detail-free schematic diagram shows the principle of the device, in particular the flow path a of the coolant K through the surface radiator 100 according to the invention. In this case, Fig.11The surface radiator 100 in FIG. 1 has a different cooling channel design. In the surface radiator 100, the LED 2 arranged on the fastening surface 12 of the housing 1 is covered by the emission window 5, which is spaced apart from the fastening surface 12 on the housing 1 and is transparent to the use radiation S emitted by the LED 2, as shown in FIG. Fig.11 . The arrangement of the emission window 5 on the housing 1 is fluid-tight, so that the housing 1, the LED 2 arranged on the fastening surface 12 and the emission window 5 defining the front side of the surface radiator 100 define an emission chamber 6 through which the fluid path a passes. Therefore, the emission chamber 6 is completely filled with the coolant K, which is therefore in direct contact with the LED 2 to absorb and dissipate the generated heat. Therefore, a thermally conductive and electrically insulating liquid is selected as the coolant K, which, like the emission window 5, is transparent to the use radiation S. Therefore, in the surface radiator 100 according to the present invention, the fluid path a starts from the inlet opening 3 formed on the outer wall of the housing 1 in the flow direction of the coolant K, passes through the first cooling channel 10, and the first cooling channel 10 extends through the housing 1 to the mouth opening 13 formed in the emission chamber 6 on the first side adjacent to the fastening surface 12. The fluid path a extends from the mouth opening 13 through the launch chamber 6 to an outflow opening 14, which is formed on a second side away from the first side, adjacent to the fastening surface 12 and connects the launch chamber 6 to a second cooling channel 11, which passes through the housing 1 and leads to a return opening 4 on the outer wall of the housing 1.

[0061] The coolant K filling the emission chamber 6 and flowing through the emission chamber 6 effectively dissipates most of the heat generated by the LED 2 during operation due to direct contact. In addition, the housing 1 can be made of a thermally conductive material, which can be a metal material, and particularly preferably aluminum or an aluminum alloy, so that a certain proportion of the heat generated by the LED 2 on the rear side of the LED 2 can also be conducted to the housing 1.

[0062] Preferably, the heat absorbed by the coolant K can be cooled outside the emission chamber 6 or outside the housing 1 after being discharged through the return opening 4, and the cooled coolant K can be supplied to the circuit again via the inflow opening 3. Therefore, the surface radiator 100 can have corresponding known elements for forming a coolant circuit. In addition, the coolant K filling the emission chamber 6 and flowing through the emission chamber 6 also ensures that the LED 2 is thermally decoupled from the environment adjacent to the emission window 5, because the coolant K can also exchange heat with the environment via the emission window 5. The coolant K filling the emission chamber 6 also advantageously ensures that near-field reflections between the LED 2 and the emission window 5 are avoided, and prevents the occurrence of volatile organic hydrocarbon compounds (VOCs) in the emission chamber 6 that may damage the LED 2. In addition, by filling the emission chamber 6 with the coolant, an explosive atmosphere is avoided. Therefore, the surface radiator 100 according to the present invention is not only improved in terms of the cooling of the LED 2 and its thermal isolation from the surrounding environment, but also protects the LED 2 from harmful substances, and in addition, compared with the prior art, it is particularly advantageous to provide an increased total light or radiation power of the radiation S. This is due to the fact that the liquid coolant K, preferably selected from saturated hydrocarbons, silicone oils and synthetic ester and ether compounds, has a refractive index significantly greater than that of air or an inert gas and, for a suitable coolant, in the range of about 1.35 to about 1.55 (at 20° C.), increases the photon decoupling efficiency at the phase boundary of the diode surface relative to the coolant K in the emission chamber 6. This reduces reflection at the phase boundary between the coolant K in the emission chamber 6 and the emission window 5.

[0063] The radiation used for the intended purpose of the surface radiator (for example for lighting, performing a photochemical reaction or disinfection) is provided by an LED, the doping of which ensures electromagnetic radiation with the intended wavelength of use. As is well known, LEDs that cover not only visible light but also infrared and / or UV spectral ranges are available. Therefore, the material selection of the emission window and the coolant may be limited by the wavelength range of the radiation used. Therefore, the radiation used for lighting is visible light, so that the emission window is transparent at least for the part of the electromagnetic spectrum with a wavelength of about 380 to 780 nm. UV radiation (100-380 nm) can be used as the radiation used for disinfection and performing a photochemical reaction, so that the emission window is made of a material that is transparent to at least the UV wavelength used in each case. For example, UV-C radiation (100-280 nm) is used for disinfection purposes. UV-B (280-315 nm) and UV-A radiation (315-380 nm) are used for many photochemical reactions, but photochemical reactions are not limited to this spectral range, because the radiation required to carry out the photochemical reaction depends on the type of reaction desired or the absorption wavelength of the starting material molecules, so the radiation used for some photochemical reactions can also optionally be within its wavelength range. Should the reference numerals here be placed here or all left out?

[0064] In principle, the emission window can also be transparent to wavelengths other than the use radiation, but it may also be desirable that the emission window is transparent only to certain wavelengths, in particular in the region of the photochemical reaction, so that the emission window can also assume a filtering function by selecting materials or coatings in order to filter out unwanted wavelengths. It is a routine activity in the art to select the window material according to the wavelength of the use radiation, for example from various glass and plastic materials. For example, the person skilled in the art knows that synthetic quartz and high borosilicate glass still have good transparency even in the UV-C range. In addition, glass ceramics show good transparency in the infrared spectral range and can be used as window materials. If the purpose is to carry out a photochemical reaction, when selecting the window material, it must be ensured that no reaction occurs with the starting materials or products. Accordingly, the coolant is selected from electrically insulating liquids according to the spectral range of the use radiation. If the window material and the coolant have a transmittance of at least 75% for the wavelength of the use radiation along the corresponding path through the emission window or through the emission chamber between the LED surface and the emission window, respectively, it is considered to be "transparent".

[0065] Liquid coolants for use with radiation in the visible and ultraviolet spectral ranges can be selected, for example, from highly refined mineral oils that contain virtually only alkanes and cycloalkanes, i.e., saturated hydrocarbons. Alkanes and cycloalkanes are advantageously transparent from the visible wavelength range to the wide UV-C range (220-230 nm). Below this value, the transmittance decreases, but it is still sufficient for wavelengths up to 195 nm and below, especially when the distance between the LED and the emission window is small enough. Cycloalkanes may be preferred due to their higher refractive index compared to the corresponding straight-chain alkanes. Thus, the refractive index (20°C) of C5-C14 cycloalkanes is in the range of about 1.41 to 1.55, while the refractive index (20°C) of the corresponding linear C5-C14 alkanes is in the range of about 1.36 to about 1.43. For example, the refractive index of cyclohexane is about 1.43, while the refractive index of hexane is about 1.37. A major disadvantage of saturated hydrocarbons is the formation of highly flammable vapor-air mixtures with a temperature class of 3, which specifies a maximum surface temperature of 200°C for operation in a flammable atmosphere. Therefore, when using highly refined mineral oils as coolants, the air must be carefully sealed to avoid the formation of such flammable vapor-air mixtures.

[0066] According to a preferred embodiment of the present invention, a low-viscosity silicone oil can be provided as a coolant for use radiation in the visible and ultraviolet spectral range, which has a refractive index in the range of about 1.37 to 1.40, is advantageously non-flammable, and is transparent from the visible wavelength range to the intermediate UV-C range (about 250nm). However, below 250nm, the transmittance begins to decrease and wavelengths less than 200nm are absorbed, so silicone oil is particularly suitable for applications where it is desired to use wavelengths greater than 250nm. For applications where it is desired to use wavelengths in the range of 200 to 250nm, silicone oil is only suitable to a limited extent, namely when the distance in the emission chamber between the LED and the emission window, and therefore the absorption, is small enough to allow sufficient transmission. Otherwise, in the spectral range below 250nm, saturated hydrocarbons should be used as coolants.

[0067] Other alternative examples of coolants that can be used for radiation in the visible and ultraviolet spectral ranges according to the present invention include synthetic esters and ether compounds. Compared with mineral oils, synthetic organic ester oils have advantages such as higher temperature resistance and higher combustion and ignition temperatures, and are more environmentally friendly, but have lower aging resistance and are transparent in the mid-UV range (about 270 to 280nm), and the absorption increases significantly below this range. In addition, in the case of ether compounds, such as 1,4-dioxane with a refractive index of 1.422, the transmission extends to the middle UV range (270 to 300nm, except for ether, up to 255nm), however, below this range, the transmission decreases too steeply, so if the distance between the LED and the emission window is small enough, the ether compound can also be used as a coolant for wavelengths below 270nm. However, wavelengths less than 220nm are absorbed. However, with regard to safety technology, it must be taken into account that ether compounds form flammable vapor-air mixtures, and there are great differences between various ether compounds. For example, diethyl ether is below temperature class T4 (maximum allowable surface temperature 135° C.), while 1,4-dioxane is below temperature class 2 (maximum allowable surface temperature 300° C.), so 1,4-dioxane can be better used as a coolant.

[0068] Depending on the wavelength of the radiation used, fluorinated hydrocarbons such as perfluorinated hydrocarbons and hydrofluoroethers can also optionally be used as coolants, which are advantageously non-flammable but have absorption bands in certain wavelength ranges: if the radiation used lies outside the absorption band, fluorinated hydrocarbons, such as 3M Fluorinert Electronic Liquid or 3M Novec High-Tech Flüssigkeit from 3MTM (3M electronics, St. Paul, USA) can be used. Of course, other liquids can also be used as coolants in the surface radiator according to the invention, as long as they are electrically insulating and transparent to the wavelength of the radiation used. In order to provide a transmittance of at least 75% required for the required transparency, the distance of the emission window from the fastening surface with the LED can be minimized as much as possible, so that the distance of the emission chamber filled with coolant between the LED and the emission window is reduced accordingly - thereby reducing the absorption of the radiation used. At the same time, when determining the size of the emission chamber, the conditions for optimal flow guidance and a sufficient liquid volume for optimal heat dissipation must be taken into account with respect to the distance of the emission window from the fastening surface with the LED.

[0069] In a preferred embodiment of the surface radiator 100 according to the present invention, the first cooling channel 10 extends through the housing 1 in such a manner that Figures 1 to 10 and Figure 12 to Figure 14 As shown, on the side away from the inflow opening 3, close to the fastening surface 12, the first cooling channel 10 extends through the housing 1 at least partially in a plane parallel to the fastening surface 12. In this way, the coolant K flowing through the first cooling channel 10 can absorb a part of the heat dissipated from the LED 2 via the housing 1 during the first cooling channel 10 before the coolant K flows into and flows through the emission chamber 6, so as to dissipate most of the heat from the LED 2 by direct contact. The design of the first cooling channel 10 (the distance from the fastening surface 12 and the route under the fastening surface 12) and the matching coolant throughput can ensure that the temperature rise of the coolant passing through the first cooling channel 10 is small. The second cooling channel 11 leading to the outflow opening 14 is kept as short as possible in order to minimize the heat transfer at the housing 1, and the coolant K heated by the passage of the emission chamber 6 flows through the second cooling channel 11. Therefore, in the example shown, the outflow opening 14 is formed on the side of the fastening surface 12 close to the return opening 4.

[0070] exist Figures 1 to 11In the example of , the corresponding surface radiator 100 has a first coolant channel 10 leading from the inflow opening 3 to the outflow opening 13 and a second coolant channel 11 connecting the outflow opening 14 to the return opening 4. Depending on the size of the surface radiator 100, i.e. the number and distribution of the LEDs 2 on the fastening surface 12 and their conduction, this simple embodiment may be sufficient to effectively cool the LEDs 2. In this case, the mouth opening 13 and the outflow opening 14 are not only arranged on opposite sides of the fastening surface 12, but also associated with the diagonal corners of the fastening surface 12, so as to flow through as many LEDs 2 as possible as evenly as possible.

[0071] In order to further even out the coolant flow through the emission chamber 6, a plurality of mouth openings and outflow openings 13, 14 can be provided on the back side of the fastening surface 12 in each case, which are evenly distributed along the respective side, such as Fig.12 and 13 The schematic diagram is intended only to illustrate the corresponding principles, but is not drawn to scale and does not represent any limitation on the number and arrangement of the openings and the routes and diameter ratios of the channels. Fig.12 A variant is shown in which the first cooling channel 10 extends from the inflow opening 3 through the housing 1 to a distributor channel portion 10b, which extends in the housing 1 along a side remote from the inflow opening 3 or facing away from the inflow opening 3 relative to the fastening surface 12. The distributor channel portion 10b is connected to a plurality of mouth openings 13, which are formed on the side remote from the inflow, close to the fastening surface 12. On the other side of the fastening surface 12, close to the inflow, a corresponding plurality of outflow openings 14 are formed, which are connected to the second cooling channel 11 extending to the return opening 4 via a collecting channel portion 11a.

[0072] In a modified variant not shown, the housing 1 can have a plurality of parallel first cooling channels 10, each extending from its respective associated inflow opening 3 to a respective associated mouth opening 13. Correspondingly, the housing 1 can have a plurality of second cooling channels 11, each extending from its respective associated outflow opening 14 to a respective associated return opening 4. This embodiment is less preferred because the coolant requires a plurality of inflow and return connections. However, depending on the number, arrangement and power of the LEDs 2 used, the design of a fluid path a with a plurality of cooling channels may make sense for certain embodiments of the surface radiator 100.

[0073] Fig.13 Shows something like Fig.12The design of the fluid path a is similar to that of the embodiment of the present invention, but the difference is that the distributor channel portion 10a here is formed on the side close to the inflow relative to the fastening surface 12, that is, the side away from the mouth opening, so that the plurality of first cooling channels 10 extend from the distributor channel portion 10a through the housing 1 parallel to the fastening surface 12 to the corresponding associated mouth openings 13. By arranging the plurality of first cooling channels 10 extending parallel to the mouth openings 13 below the fastening surface 12, more uniform temperature control of the housing 1 through two passages of the coolant through the first cooling channels can be achieved if necessary, rather than in the case of the most single cooling channel 10 extending straight on one side below the fastening surface 12. However, if the cooling channel 10 has a route that uniformly covers the fastening surface 12, for example Fig.14 Even if the cooling channel 10 is curved, more uniform temperature control can be achieved by using only one cooling channel 10. Figures 1 to 11 A simpler cooling channel design of the example can be manufactured by drilling holes on one or both sides in the housing 1, where the direction of the cooling channel section changes at most once, but more complex cooling channel designs with more than one change in direction of the channel section require multi-side drilling, followed by closing of the hole sections that are not part of the fluid path, or, if necessary, a generative manufacturing method of the housing.

[0074] In order to arrange the emission window 5 on the housing 1 in a fluid-tight manner so as to seal the emission chamber 6 filled with the coolant K from the environment, Figures 1 to 10 In the exemplary surface radiator 100 shown, a holding frame 17 is provided, which in this example is detachably fixed to the housing 1 by means of screws 50, for which purpose corresponding fastening holes 19 are provided in both the holding frame 17 and the housing 1. The holding frame 17 defines an opening 17a, the area size of which substantially corresponds to the fastening surface 12, so that the LED 2 is not covered and the radiation is allowed to escape through the emission window 5. In this case, the sealing of the emission chamber 6 is achieved by arranging corresponding circumferential seals 18 between the holding frame 17 and the emission window 5 and between the emission window 5 and the housing 1, for which purpose the holding frame 17 and the housing 1 each have a corresponding sealing groove 18a (at Figure 6 , for receiving a sealing cord or a corresponding sealing element.

[0075] Fig.11 The exemplary surface radiator 100 according to the present invention dispenses with a holding frame, because the emission window 5 is fastened to the housing 1 and sealed at the same time by means of an adhesive layer 60. Therefore, the surface radiator 100 is designed to have almost no edges and is therefore particularly suitable for seamless installation into, for example, a reactor wall element of an apparatus for performing a photochemical reaction.

[0076] Of course, variations and combinations of fastening and sealing of the emission window to the housing are also conceivable, for example, the emission window is fastened and sealed to a retaining frame detachably fastened to the housing by an adhesive layer, the arrangement of the retaining frame on the housing being sealed by a sealant.

[0077] If the surface radiator according to the invention is used in a device for carrying out a photochemical reaction, the sealing of the emission window on the housing is designed in terms of material selection and shape to correspond to the expected reaction pressures and reaction temperatures that may prevail in the reaction chamber adjacent to the emission window. These include in particular reaction temperatures and pressures that differ from room temperature and ambient pressure, which prevail in the reaction chamber adjacent to the emission window, and may also include temperatures below +5° C. and above +40° C. and pressures in the range of high vacuum and 6 bar overpressure.

[0078] As in Figure 6 As can be seen particularly clearly in FIG. 1 , the housing 1 of the illustrated exemplary embodiment of the surface radiator 100 according to the invention has a first fastening shoulder 12a for arranging the emission window 5 and a second fastening shoulder 12b for arranging the holding frame 17, which surround the fastening surface 12 in a stepped manner. In this case, the first fastening shoulder 12a is defined by the step of the second fastening shoulder 12b, the dimensions of the surface defined thereby corresponding to the emission window 5 to be arranged, and the height of the step to the second shoulder 12b corresponds to the thickness of the emission window 5. The height of the step of the first fastening shoulder 12a relative to the fastening surface 12 determines the distance of the emission window 5 from the fastening surface 12 and thus the height of the emission chamber 6, which defines the distance of the radiation emitted by the LED 2 through the coolant K. The second fastening shoulder 12b for the holding frame 17 is also defined by a boundary web, wherein the dimensions of the surface defined thereby and the height of the boundary web correspond to the corresponding dimensions of the holding frame 17 to be arranged.

[0079] Fig.11 The housing 1 of the example of the embodiment of the present invention, in which the emission window 5 is fastened to the housing 1 by means of an adhesive layer 60, also has a first fastening shoulder 12a, but is not surrounded by a further fastening shoulder or web, so that the emission window 5 covers the front side of the housing 1. Unlike the example shown, in order to arrange the emission window fastened by means of the adhesive layer, the boundary of the first fastening shoulder 12a can also be provided by a further shoulder or web, whereby the dimensions of the surface of the boundary and the height of the boundary web correspond to the corresponding dimensions of the emission window.

[0080] In order to accommodate the electrical connection elements for the LED 2, Figures 1 to 8The surface radiator 100 according to the invention of the example of 10 and 11 has, on the front side in the housing 1 adjacent to the fastening surface 12, a connection chamber 15 which is formed between the first and second cooling channels 10, 11 in the housing 1 and is open toward the emission chamber 5. In the example shown, the connection chamber 15 is covered by a holding frame 17, for which purpose the holding frame 17 has a wider frame section on the respective side. A connection opening 16b in the housing 1 is formed together with the connection chamber 15 by means of a channel opening 16a, which allows an electrical connection to a power source. Fig.10 In the example shown, the electrical connection elements extending into the connection chamber 15 comprise connection wires 22 for connecting the LED 2 .

[0081] In the exemplary surface radiator 100 shown, the light-emitting semiconductor components 2 are arranged on a circuit board 20, which has corresponding conductor tracks (not shown) for connecting the LEDs 2, which lead to connection contacts 21 arranged on the side of the circuit board 20 close to the connection chamber 15. In each case, a pair of connection contacts 21 is provided for each row of LEDs 2 and is connected to corresponding connection lines 22. Figures 1 to 8 As shown in the example of FIG. 5 , the circuit board 20 can be fastened to the fastening surface 12 of the housing 1 by means of screws 50 , and the housing 1 has corresponding fastening holes 19 .

[0082] However, if Fig.11 As shown, the LEDs 2 can also be fastened individually to the fastening surface 12 without a circuit board 20. Each LED 2 can then have its own connection, which is particularly suitable for surface radiators 100 with a limited number of LEDs or surface radiators 100 in which the LEDs are arranged in a single row, which allows a lateral connection of each LED. In the case of surface radiators with multiple rows of LEDs, if a circuit board 20 with conductor tracks for the electrical connection of the LEDs is not required, it can be provided that the fastening surface has grooves, for example. The grooves are introduced into the fastening surface in such a way that the connection lines to the respective LEDs can extend therein and thus no shadowing of the LEDs is produced by the connection lines. The individual connections of the LEDs, which can thus be individually controlled, make it necessary that in the event of failure of one LED, only the affected LED needs to be switched off, rather than all the LEDs, so that the remaining LEDs remain operational.

[0083] Fig.15a) shows a conventional LED 2 with a plastic lens as primary optics 2a, which can be used in the LED surface radiator 100 according to the invention. Flooding with a coolant is advantageous compared to the use of an inert gas such as nitrogen, in order to avoid accelerated aging of the primary optics 2a of the LED 2, since VOCs ("volatile organic compounds") are present in particular in chemical plants, which penetrate into the primary optics 2a, which are usually designed as silicone lenses, darken them, and thus reduce the light output. Since, according to the invention, the primary optics 2a is no longer exposed to any gas-containing atmosphere, but is shielded by the coolant, the aging process is significantly slowed down. In order to completely avoid a limitation of the light output due to aging processes of the primary optics 2a, in the surface radiator 100 according to the invention, the LED 2 of the surface radiator 100 can advantageously completely dispense with the primary optics 2a, for example a silicon lens, since the liquid coolant already adequately protects the semiconductor chip of the LED from environmental influences and the coolant takes over the function of the primary optics. Fig.16 shows an LED 2 without primary optics, the structure of which may correspond to Fig.15 The semiconductor crystal 2b, wire 2c, anode 2d, LED chip 2e, cathode 2f and base structure 2g or circuit board 20 of the conventional LED 2 are combined, wherein in addition to saving components, the cooling effect is further improved.

[0084] In addition, if Fig.10 As shown, a ballast 24 for LED 2 connected to the connecting line 22 can be accommodated in the connection chamber 15. Due to the fluid connection of the connection chamber 15 with the emission chamber 6, the connection chamber 15 is also filled with a coolant and can take away the heat generated by the ballast 24 during operation. Therefore, the arrangement of the ballast 24 on the circuit board 20 can be omitted, thereby avoiding the ballast 24 from inputting heat to the adjacent LED 2 via the circuit board 20. However, it is not excluded to arrange the ballast 24 on the circuit board 20 in the surface radiator 100 according to the present invention, because in such an embodiment, the coolant also ensures effective heat dissipation. In addition, an alternative ballast not shown, such as a DC converter or a power supply unit, can be installed on the housing on the rear side of the housing attachment. Here, liquid coolant can also be used to cool the DC converter or other ballast by connecting the housing attachment to the cooling circuit. In order to operate safely through ATEX certification, the inertization, pressure-resistant design or oil encapsulation of the rear housing attachment can be achieved. Another alternative, not shown, can provide that the ballast is arranged outside the connection chamber and the emission chamber, so that only the connection line 22 is located in the connection chamber 15 and can extend to or through the connection opening 16b. This means that electrical or electronic devices, such as DC converters or other ballasts, can also optionally be placed in a separate housing close to the housing of the surface radiator. If the surface radiator 100 is operated in an explosion-proof area, the separate housing can be installed outside the explosion-proof area.

[0085] exist Fig.10 The connection plug 23, which is connected to the ballast 24 in the embodiment but can also be connected to the connection line 22, extends from the connection chamber 15 through the passage opening 16a having a smaller cross-sectional area than the connection opening 16b and through the connection opening 16b, so that the electrical connection of the surface radiator 100 can take place from the outside. In this case, the connection plug 23 can have a portion whose cross-sectional area corresponds to the cross-sectional area of ​​the passage opening 16a, such as Figure 3 As shown, the passage opening 16a can deviate from a circular shape and is designed as a double plane in the example shown therein. Fig.10 Different from the above, the connection plug 23 may have a stepped shape so that the connection plug 23 has not only a portion adapted to the cross section of the passage opening 16a, but also a portion adapted to the cross section of the connection opening 16b, so as to seal the connection chamber 15. Alternatively or additionally, in order to seal the arrangement of the connection plug 23 in the connection opening 16b and / or the passage opening 16a, a potting or solder block may be used to avoid leakage due to the insulation of the connection plug 23. The same applies to embodiments of the arrangement of the cable having the connection wire 22 or including the connection wire 22 and extending through the passage opening 16a and the connection opening 16b, so as to prevent the coolant from leaking from the connection chamber 15, so that the coolant does not penetrate to the outside through the insulation or shielding of the wire due to the capillary effect.

[0086] Similarly, the arrangement of the inlet connection element 30 arranged in the inlet opening 3 formed in the housing 1 and thus providing the inlet connection of the surface radiator 100 and the return connection element 40 arranged in the return opening 4 formed in the housing 1 and thus providing the return connection of the surface radiator 100 (see Figure 1 , 2 , 5, 7, 8) can also be sealed by potting or solder bumps to prevent leakage.

[0087] In principle, all connection points can be fluid-tight to prevent the coolant from penetrating to the outside of the surface radiator 100 along the corresponding connection elements by capillary effect. For this purpose, measures such as casting the pipeline section into the housing 1 and / or a plug connection sealed by a seal may be sufficient. In addition, preferably, all electrical connections surrounded by the coolant or in contact with the coolant can be fluid-tight to prevent the coolant from penetrating due to creep and capillary effects caused by surface tension, for example between the contact points, where the electrical contact may deteriorate or be interrupted. In the case of a plug connection, a sealed plug may be sufficient in some cases, but further measures, such as welding the contact points, may also be required in order not only to avoid creep of the coolant but also to ensure electrical contact.

[0088] According to the emission spectrum of the LED 2 used, the surface radiator 100 according to the present invention can be used for lighting, photochemical reaction or disinfection, so the arrangement of the inflow opening 3 and the return opening 4 on the housing 1 and the connection opening 16b depends on the installation environment of the surface radiator 100 in the corresponding lighting, photochemical reactor or disinfection device. Figures 1 to 10 As shown in the examples of FIGS. 12 to 14 , the inflow opening 3 and the return opening 4 may be arranged together on the side of the housing 1 . Figures 1 to 8 and Fig.10 As shown in the example of FIG. 1 , the connecting opening 16 b may also be arranged on the same side as the inflow opening 3 and the return opening 4 . Fig.11 The exemplary embodiment of the surface radiator 100 in FIG. 1 shows the arrangement of the inflow opening 3 and the return opening 4 on the rear side of the housing 1, similar to Fig.17 In the case of the surface radiator 100 of the device 110 , as can be seen from the shown inflow and return flow connecting elements 30 , 40 , each inflow and return flow connecting element 30 , 40 is connected to an inflow and return flow opening not shown here. Fig.17 Also shown is a connection plug 23 arranged in a connection opening (not shown) on the rear side of the housing 1. However, the inlet, return and connection openings 3, 4, 16b can also be arranged on different sides of the housing 1, for example Fig.18 It can be seen from the surface radiator 100 of the device 110 shown that the inflow connection element 30 connected to the inflow opening (not shown) is arranged on the rear side of the housing 1, and the return connection element 40 connected to the inflow opening (not shown) and the connection plug 23 arranged in the connection opening (not shown) are arranged on the side faces facing away from each other of the housing 1. However, the device 110 according to the present invention is not limited to the arrangement of the inflow, return and connection openings 3, 4, 16b shown in the example, which can be based on the corresponding installation environment and changed accordingly.

[0089] Since active cooling by direct contact of the LED with the coolant allows the use of surface emitters with multiple LEDs or their operation at maximum power, high power densities are achieved, which can compete with low- and medium-pressure emitters in the photochemical field. Handling and controlling the thermal balance of the LED surface emitters (thermal management in short), which also has to take into account the process temperature of the reaction medium adjacent to the emission window of the surface emitter, is crucial for a sufficient lifetime of the LED.

[0090] Fig.17A first example of an apparatus 110 according to the invention is shown, which is configured to carry out a photochemical reaction with a surface radiator 100 according to the invention, the LED 2 of the surface radiator 100 providing an emission spectrum for carrying out the photochemical reaction. The apparatus 110 for carrying out a photochemical reaction is a photoreactor, the housing of which comprises a reactor vessel 111 and a reactor cover 112. In the example shown, the mounting position provided for the surface radiator 100 is arranged in the reactor cover 112, other reactor devices may also provide mounting positions in the wall of the reactor vessel 111. In addition, the reactor device 110 may have a plurality of mounting positions for a plurality of surface radiators. For installation in the reactor cover 112, the housing 1 of the surface radiator 100 has a fastening hole 101 as a mounting element (see also Figure 1 and Fig.10 ), so that the surface radiator 100 can be fastened in the reactor cover 112 by screws or bolts. In order to achieve optimal cooling of the LED 2 by taking away the heat from the outside of the surface radiator 100 in this case, too, a coolant that absorbs not only the heat generated by the LED 2 but also the heat from the exothermic reaction is guided from the coolant of the reaction chamber adjacent to the emission window 5 in a circuit, which is guided from the return connection element 40 via a coolant return line 114 in a circuit line 116, which includes a pump and an optional heat exchanger and / or accessories, for example for regulating the pressure in the emission chamber, and via a coolant inlet line 113 to a valve of the inlet connection element 30. Furthermore, it is shown that the surface radiator 100 is electrically connected to the connection plug 23 via a connecting cable 115 to a power supply and control device 117. The power supply and control device 117 can be an external power supply and control device, which can include, for example, a ballast or power electronics, a driver (if not accommodated on a circuit board or in a connection chamber) and power supply components.

[0091] exist Fig.18 In the illustrated device 110, the surface radiator 100 is shown with inflow and return connection elements 30, 40 and a connection plug 23, wherein in this case the device 110 can also have a connection for the coolant to flow from the return connection element 40 via the return, return, inflow line to the corresponding Fig.17 The circuit design of the inflow into the connecting element 30 (not shown here). In addition, the device 110 can have the power supply shown for the surface radiator 100, which can be connected to the connecting plug 23, for example, via a connecting cable. Fig.18The exemplary device 110 shown is constructed for disinfecting the surface of an object G, wherein the front side of the surface radiator 100 faces in the direction of a conveyor belt 118, and the object G to be disinfected is transported below the surface radiator 100 on the conveyor belt 118, so that the radiation S used for disinfection in the UV-C spectrum range emitted in the radiation area of ​​the surface radiator 100 hits the surface of the object G during transportation and eliminates the bacteria present therein. The installation environment of the surface radiator 100 in the device 110 for disinfection includes a holder 119 as a housing, and the surface radiator 100 is arranged at a predetermined distance above the conveyor belt 118 by means of the holder 119. For this purpose, the surface radiator 100 has a fastening hole 101 on the housing 1 (see also Figure 1 and Fig.10 ), for example a pin or a screw can be engaged into the fastening hole 101 to fasten to the retainer 119.

[0092] The type and number of mounting elements should not be limited to the fastening holes shown, as the type and number of mounting elements may also depend on the installation environment and the size and design of the surface radiator 100. All mounting elements may be designed to form preferably removable plugs, screws, plug screws, clamping connections, etc. Alternative or additional mounting elements (not shown) may be, for example, but not limited to, pins, tabs, collars, webs or flanges, or may also be profiled protrusions or profiled recesses for engagement with corresponding mating profiled elements, which may support or simplify the installation of the surface radiator 100 in the device 110.

[0093] The protective scope of the invention should not be limited to the two shown examples of devices comprising a surface radiator 100 according to the invention.

[0094] The surface radiator with improved cooling according to the invention can be used for any purpose of lighting, photochemical reaction or disinfection with LED, the emission spectrum of which is the corresponding use radiation for lighting, photochemical reaction or disinfection. Accordingly, the device for lighting and the device for photochemical reaction or disinfection also include devices different from the examples shown, which include the surface radiator according to the invention and are not within the scope of protection.

[0095] With regard to the operation of the surface radiator 100 according to the invention with a circulating coolant in a photoreactor or a device for carrying out a photochemical reaction, attention must be paid to the flow rate, in particular in the case of silicone oil, keeping the flow rate low, i.e. preferably below 1 m / s, since otherwise in the case of non-conductive products present in the photoreactor, electrostatic charging may occur and there is a danger of forming an ignition source. In order to meet the current requirements of ATEX certification with regard to "o" = oil seal, the kinematic viscosity of the coolant (at 25°C) must be at least 20 cSt, even if a coolant with a lower viscosity (e.g. 5 cSt) is technically more advantageous for circulation and maintaining the LED surface temperature. The coolant can therefore have a kinematic viscosity (at 25°C) of 5 to 60 cSt, wherein, according to the applicable explosion protection standards, a viscosity in the range of 20 to 50 cSt is preferred in order to obtain the corresponding certification. In the case of using a coolant with a high viscosity, in order to avoid internal pressure losses, it is also advantageous to dimension the return and inflow connection lines with a sufficiently large diameter to avoid excessive pressure on the LED.

[0096] In order to maintain the surface limit temperature of the LED, in another embodiment for controlling the coolant flow rate, since the flow rate of the coolant guided in the loop should not be lower than a predetermined minimum value, the surface radiator or the upper device can additionally have a flow meter, which is connected to a control unit, and the control unit is configured to control a pump and / or an accessory (valve) connected to one of the return and inflow connection lines according to the flow value measured by the flow meter, so as to maintain a predetermined flow rate of the coolant through the emission chamber along the surface of the LED. The control unit can be a separate unit, a part of a flow meter, a pump or an accessory, or a part of a control device of the upper device. Due to the high viscosity required for explosion protection and the low flow rate to be maintained, a mass flow meter, such as a Coriolis mass flow meter or a float flow meter or other suitable measurement methods, can be preferably used, while a vortex flow measurement device is quite unsuitable. For the high viscosity and low flow rate required for ATEX certification, a Coriolis mass flow meter that meets the ATEX certification safety integrity level ("safety integrity level", referred to as SIL) is particularly suitable as a flow meter. However, a float flow meter that can be used alternatively also provides reliable measurement values ​​at high viscosity and low flow rate of the coolant. Furthermore, a breathing unit with a desiccant can be arranged in one of the circuits or coolant connecting lines, preferably at the highest point, to allow coolant to be vented to avoid condensation, thereby preventing the introduction of moisture into the fresh air through the desiccant, such as silica gel.

[0097] In order to separate the LED from the conditions prevailing in the environment adjacent to the emission window and not to impair the operability of the LED, the emission window can be a double-walled emission window, or the surface radiator or the superordinate device can have a second emission window covering the emission window that confines the emission chamber. The gap formed between the two emission windows or the double walls provides further thermal decoupling. This can be further enhanced by using a suction device to create a negative pressure in the gap or by connecting another cooling circuit for cooling the fluid in the gap. When designed as a double-walled emission window, the gap between the walls can also be evacuated during its two manufacturing processes. All liquid or gaseous fluids that are transparent to the radiation used, for example water, inert gases such as nitrogen or air, are suitable as cooling fluids.

[0098] In some embodiments, the surface radiator according to the present invention can also have a plurality of circuit boards, each circuit board having a part of the total number of LEDs, depending on the number of LEDs used, wherein the circuit boards can be individually manipulated. This makes it unnecessary to turn off all LEDs when an LED on a circuit board fails, but only the affected circuit board needs to be turned off, while the other circuit boards can continue to work. The replacement of the relevant circuit board can be postponed to a suitable time, for example, after the photochemical reaction carried out by the surface radiator is over. To this end, the surface radiator of each circuit board can have a detection unit, which is configured to detect the failure of one or more LEDs on the circuit board, and according to the detected failure, interrupt the power supply of the relevant circuit board, and if necessary, limit the power supply of other circuit boards accordingly. If necessary, when the detection unit is connected to the power supply and control device, a warning message can also be output via the control device or the superior device of the surface radiator. In principle, each LED can also imagine such a detection unit, so that in the case of a single LED failure, the corresponding power supply is interrupted, and if necessary, the power supply to other LEDs is limited accordingly, thereby avoiding the LED failure associated with the temperature hot spot leading to a chain reaction, resulting in the failure of other LEDs due to a temperature higher than the maximum limit temperature.

[0099] Furthermore, the surface radiator can have one or more temperature sensors, which are arranged on the housing or on the circuit board and are connected to a power supply and control device, which includes a circuit breaker for the LED. When the maximum permissible ambient temperature is exceeded, the circuit breaker provides a protective shutdown to protect the semiconductor components. If the LEDs or LED groups of the surface radiator can be controlled individually and if temperature sensors are associated with the LEDs or LED groups, the control device can shut down the LED or LED group associated with the sensor when one of the sensors detects that the maximum temperature is exceeded. Correspondingly, when the sensor determines that the maximum temperature is below due to the protective shutdown, the control device can automatically switch on the corresponding LED / LED group again. All safety-related sensors of the surface radiator, such as identification units and temperature sensors, can be redundant or dual-channel in order to achieve the corresponding necessary SIL level.

[0100] Alternatively or additionally, the power supply and control device may also include at least one control circuit for LED control, with which the same or different LEDs can be dimmed and / or the spectrum of the emission wavelengths of different LEDs can be changed in order to adjust the amount of emitted light or the emission wavelength as desired or required. Thus, an application- or process-specific spectrum can be provided, and furthermore, the radiation intensity can be adapted to the application, such as a photochemical process, by means of a control loop. Thus, for example, in a device for carrying out a photochemical reaction, an LED power regulation (dimming) for process control can be performed, since in many reactions the absorption changes during the process. This can be responded to by targeted measurement and control circuits and LED dimming in order to achieve an efficient system and avoid excessive radiation.

[0101] The surface radiator according to the invention can have a monochromatic LED as well as a mixture of LEDs with different emission spectra, which provide the best use of radiation, which corresponds to the execution of the photochemical reaction or the disinfection of the optimal utilization of the absorption spectrum of the corresponding reaction. This also applies when the device for carrying out the photochemical reaction is a bioreactor. Here, LEDs with different emission wavelengths can be implemented to achieve an optimal growth rate. At different growth stages or for different cells, in each case an optimal mixture of spectra and intensities can be used to optimize growth.

[0102] Reference numerals list

[0103] 1 Shell

[0104] 2Light emitting semiconductor components (LED)

[0105] 2a, 2b, 2c main optical devices, semiconductor crystals, wires,

[0106] 2d, 2e, 2f, 2g anode, LED chip, cathode, base structure

[0107] 3 Inflow opening

[0108] 4 Return opening

[0109] 5 Launch Window

[0110] 6 Launch Room

[0111] 10, 10a, 10b first cooling channel, distributor channel portion close to the inflow and away from the inflow

[0112] 11. 11a Second cooling channel, collecting channel part

[0113] 12 Fastening surface

[0114] 12a, 12b Fastening shoulders

[0115] 13 Mouth opening

[0116] 14 Outflow opening

[0117] 15 Connection Room

[0118] 16a, 16b channel opening, connection hole

[0119] 17, 17a holding frame, opening

[0120] 18, 18a seal, sealing groove

[0121] 19 Fastening holes

[0122] 20 Circuit Board

[0123] 21 Connecting contact pairs

[0124] 22 Connection cable

[0125] 23 Connecting plug

[0126] 24 Drivers / Ballasts

[0127] 30 Inflow connection element

[0128] 40 Return connection element

[0129] 50 Fasteners

[0130] 60 Adhesive layer

[0131] 100 Surface Radiator

[0132] 101 Mounting components

[0133] 110 Devices for lighting, photochemical reactions or disinfection

[0134] 111 Reactor vessel

[0135] 112 Reactor cover

[0136] 113 Coolant inlet line

[0137] 114 Coolant return line

[0138] 115 connection cable

[0139] 116 loop pipeline (with pump and optional heat exchanger)

[0140] 117 Power supply and control device

[0141] 118 conveyor belt

[0142] 119 Retainer

[0143] a Fluid Path

[0144] G Processing object

[0145] K Electrical insulating coolant

[0146] S Use Radiation

Claims

1. A surface radiator (100), comprising at least one light-emitting semiconductor component (2) and a housing (1), wherein: the housing (1) has at least one cooling channel (10, 11) for a coolant, the cooling channel forming at least a part of a fluid path (a) extending from an inlet opening (3) formed in the housing (1) to a return opening (4), and an emission window (5) is arranged on the housing (1), which emission window covers at least one light-emitting semiconductor component (2), defines a front side of the surface radiator (100) and is transparent for the use radiation (S) that can be emitted by the semiconductor component (2), It is characterized in that The housing (1) provides a fastening surface (12) for the light emitting semiconductor component (2) which is spaced apart from the emission window (5), wherein the arrangement of the emission window (5) on the housing (1) is fluid-tight, and the housing (1), the at least one light emitting semiconductor component (2) and the emission window (5) define an emission chamber (6), and the fluid path (a) is defined by, i) at least one first cooling channel (10) extending from the inlet opening (3) through the housing (1) to at least one mouth opening (13) formed on a first side adjacent to the fastening surface (12), and ii) an emission chamber (6) extending from the at least one mouth opening (13) to the at least one outflow opening (14), the at least one outflow opening being formed on a second side remote from the first side adjacent to the fastening surface (12), and iii) at least one second cooling channel (11) extending from the outflow opening (14) through the housing (1) to the return opening (4), wherein the coolant (K) is an electrically insulating liquid transparent to the use radiation (S).

2. The surface radiator (100) according to claim 1, It is characterized in that The housing (1) is configured to arrange the surface radiator (100) in a device (110) for lighting, photochemical reaction or disinfection, wherein the housing (1) has a rear side facing away from the front side and is defined by a side surface between the front side and the rear side, wherein the inlet opening (3) and the return opening (4) are arranged together on one of the side surfaces or the rear side, or are arranged separately on different side surfaces or on one of the side surfaces and the rear side.

3. The surface radiator (100) according to claim 1 or 2, It is characterized in that The at least one mouth opening (13) is formed on a side of the fastening surface (12) remote from the inlet opening (3), wherein the first cooling channel (10) at least partially extends through the housing (1) in a plane parallel to the fastening surface (12), wherein the at least one outflow opening (14) is preferably formed on a side of the fastening surface (12) close to the return opening (4).

4. The surface radiator (100) according to at least one of claims 1 to 3, It is characterized in that - the inflow opening (3) is fluidically connected to a distributor channel portion (10a) adjacent to the inflow opening (3), a plurality of first cooling channels (10) extend from the distributor channel portion to a corresponding plurality of mouth openings (13) on a side of the fastening surface (12) remote from the inflow opening (3), and the second cooling channel (11) extends from a collecting channel portion (11a) connected to a plurality of outflow openings (14) to the return opening (4), or - the first cooling channel (10) extends from the inlet opening (3) to a distributor channel portion (10b) remote from the inlet opening (3), a plurality of mouth openings (13) being formed at the distributor channel portion, and the second cooling channel (11) extends from a collecting channel portion (11a) connected to a plurality of outflow openings (14) to the return opening (4).

5. The surface radiator (100) according to at least one of claims 1 to 4, It is characterized in that -in, The surface radiator (100) comprises a holding frame (17) which is arranged on the housing (1) for holding the emission window (5) and is configured such that the at least one light-emitting semiconductor component (2) is not covered, wherein in each case a circumferential seal (18) is arranged between the holding frame (17) and the emission window (5) and between the emission window (5) and the housing (1), and / or The emission window (5) is fixed to the housing (1) by means of an adhesive layer (60).

6. The surface radiator (100) according to at least one of claims 1 to 5, It is characterized in that The housing (1) has at the front side at least one fastening shoulder (12a, 12b) surrounding the fastening surface (12), wherein the first fastening shoulder (12a) is configured to accommodate the firing window (5) and the distance between the first fastening shoulder (12a) and the fastening surface (12) defines the height of the firing chamber (6).

7. The surface radiator (100) according to at least one of claims 1 to 6, It is characterized in that A connection chamber (15) leading to the emission chamber (6) is formed in the housing (1) on the front side adjacent to the fastening surface (12), wherein a connection opening (16b) connected to the connection chamber (15) is formed on the housing (1), wherein at least one connection line (22) for connecting the at least one light-emitting semiconductor component (2) extends at least into the connection chamber (15).

8. The surface radiator (100) according to claim 7, It is characterized in that The surface radiator (100) has a plurality of light-emitting semiconductor components (2) arranged on at least one circuit board (20), the plurality of light-emitting semiconductor components (2) being fastened to the fastening surface (12) via the circuit board, wherein a pair of connection contacts (21) for a row of light-emitting semiconductor components (2) are formed on the circuit board (20) on one side of the circuit board (20) close to the connection chamber (15) in each case, and each connection contact (21) is connected to a corresponding connection line (22).

9. The surface radiator (100) according to claim 7 or 8, It is characterized in that A ballast (24) for the at least one light-emitting semiconductor component (2) is arranged in the connection chamber (15), the ballast being connected to the at least one connection line (22).

10. The surface radiator (100) according to at least one of claims 7 to 9, It is characterized in that The connection opening (16b) is connected to the connection chamber (15) via a passage opening (16a), wherein the cross-sectional area of ​​the passage opening (16a) is smaller than the cross-sectional area of ​​the connection opening (16b).

11. The surface radiator (100) according to at least one of claims 7 to 10, It is characterized in that The at least one connecting line (22) extends at least partially into the connecting opening (16b), wherein the arrangement of the at least one connecting line (22) in the connecting opening (16b) is sealed by potting or a solder bump, or A connection plug (23) is connected to the at least one connection line (22), wherein the connection plug (23) at least partially extends into the connection opening (16b), wherein the arrangement of the connection plug (23) in the connection opening (16b) is sealed by potting or a solder bump.

12. The surface radiator (100) according to at least one of claims 1 to 11, It is characterized in that The surface radiator (100) comprises an inflow connection element (30) connected to the inflow opening (3) and a return connection element (40) connected to the return opening (4), wherein the connection between the inflow connection element (30) and the inflow opening (3) and / or the connection between the return connection element (40) and the return opening (4) are sealed by potting or a solder bump.

13. A device (110) for lighting, carrying out a photochemical reaction or disinfection, comprising a surface radiator (100) having at least one light-emitting semiconductor component (2), the emission spectrum of which provides the corresponding use radiation (S) for lighting, heating, carrying out a photochemical reaction or disinfection, It is characterized in that The surface radiator is a surface radiator (100) according to at least one of claims 1 to 12.

14. The device (110) according to claim 13, It is characterized in that The device (110) has a housing (111, 112, 119), which at least partially surrounds an illumination chamber, a reaction chamber or a disinfection chamber and has at least one mounting position for at least one surface radiator (100), the housing (1) of the surface radiator preferably having at least one mounting element (101) for being arranged in the device (110).

15. Use of the surface radiator (100) according to at least one of claims 1 to 12 for lighting, photochemical reactions or disinfection, wherein: The at least one light emitting semiconductor component (2) has an emission spectrum which provides suitable use radiation (S) for illumination, for carrying out photochemical reactions or for disinfection.

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