The invention relates to a stationary infrared radiator which is to be operated in a decentralized manner for heating buildings, having a reflector and at least two different components emitting IR radiation for heating, wherein the reflector has a longitudinal axis and a transverse axis extending at right angles to the longitudinal axis and parallel to the reflector, and a reflector surface. The first component is designed as a light radiator or as a dark radiator and has a connection for supplying fuel gas. The second component is designed as an electric resistance heater having at least one heating element. The infrared radiator is preferably mounted suspended from a ceiling.
A stationary infrared radiator which is to be operated in a decentralized manner is to be understood as a heating device, in particular for halls, which is primarily designed as a ceiling device and is directly operated using fuel gas and/or electrical energy. Such decentralized infrared radiators generate the thermal energy themselves and emit it to the environment via the respective radiating components, overwhelmingly in the form of IR radiation. They function, when driven by fuel, in a temperature range between 300° C. and 900° C. and, when driven by electricity, at up to 1200° C. Fuel gas and also fuel oil are to be understood as fuels. In the case of centrally operated radiators, the thermal energy is centrally generated outside of the respective radiator and hydraulically supplied to the radiators by means of heat exchangers, in contrast to decentralized radiators.
Operating infrared radiators with a burner and indirectly in combination with electrical energy, is already known. EP 2 492 600 B1 describes heating the combustion air with the aid of solar energy before introducing it into the burner, wherein electrical energy is also used in addition to thermal energy.
EP 3 239 616 B1 describes a system of an infrared radiator, in which the radiant tube is produced from stainless steel and is heatable both using fuel gas and also using an electric resistance heater.
DE10 2009 021158 A1 describes the basic design of an infrared radiator with a reflector designed as a housing with a reflector surface and with an additional tube reflector arranged between the radiant tube and the reflector surface. An alternative design of a generic infrared radiator is known from DE10 2012 025299 A1, in which a reflector is accommodated by a separate housing and additional tube reflectors are also provided. The respective reflector forms a hood for the warm air generated by the infrared radiators. According to CN 203 605 313 U, a floor unit is known, in which a gas heating device and an electric heating device are combined.
The underlying object of the invention is to design an infrared radiator, which may be operated using different energy media, and arrange it in such a way that it may be more precisely controlled as a ceiling unit with respect to its temperature and is simultaneously easier to produce.
The problem is solved according to the invention in that the first component and the second component are arranged in front of the reflector surface offset from one another in a direction of the transverse axis and/or the first component and the second component are arranged in front of the reflector surface offset from one another in a direction perpendicular to the longitudinal axis and/or in a direction perpendicular to the transverse axis. The preferred solution is also included in this solution, that the first component and the second component are respectively arranged in front of the reflector surface offset from one another in a direction of the transverse axis and in a direction perpendicular to the longitudinal axis and to the transverse axis.
Due to the offset and during pure electrical operation, the electric heating element partially heats the component of the dark or light radiator provided for emitting. The dark radiator preferably forms an exhaust gas pipe, functioning as a radiant tube, for combusting the fuel gas. In particular in the case of dark radiators, the radiant energy of the electric heating element, captured or absorbed by the exhaust gas pipe designed as a radiant tube, is discharged or emitted again as radiant heat. Since the dark radiator or light radiator is likewise completely located under the reflector, the so-called shading of the electrically-generated IR radiation thus does not negatively impact the radiation factor or the efficiency of the infrared radiator. The advantage of the shading is significant in the case of power adjustment by means of pulse width modulation of the electric heating element. In this case, the mass of the dark radiator or light radiator results in additional inertia, which results in a favorable equalization of the temporal radiation profile. The advantage according to the invention is greater due to the design and geometry used in dark radiators than for light radiators. Another advantage which supports this effect is the convection trough usually formed by the reflector or the hood of the reflector, in which the warm air collects and thus prevents any convection losses due to shadowing.
Regardless of the advantage for pulse width modulation, the structural separation of the radiant tube or incandescent body for the fuel gas energy medium from the resistance heater for the electrical energy medium achieves that the radiant temperatures may be controlled in a targeted way for each medium in isolation. Due to the structural separation, the respective surface temperatures do not substantially influence each other in bivalent operation of the infrared radiator, thus when it is heated with fuel gas and simultaneously with electricity. With respect to the relevant prior art, the necessity of electrical insulation of the radiant tube is thereby eliminated as well as the processing of stainless steel for the radiant tube.
According to the invention, the method for operating an infrared radiator is also advantageous, in which the radiant tube captures the radiation energy of the electric heating element through absorption and the mass inertia of the radiant tube is used for equalizing the temporal radiation profile of the infrared radiator in the case of pulse width modulation of the electric heating element. The radiant tube causes a shadow for the radiation of the heating element or a shading of the electrically-generated IR radiation, which is advantageously exploited.
It may also be hereby advantageous if both components are attached to the infrared radiator structurally separated or independently from one another. Each component may thus be designed and installed in isolation, without having to take structural features of the respective other components into consideration. The infrared radiator has a mounting, which is designed, for example, as a reflector, housing, and/or as a bulkhead, wherein the respective components are attached to the mounting.
It may be further advantageous if a separate tube reflector is provided between the reflector and the component. Due to the tube reflector, it is possible to set the radiation sector and the radiation direction of the respective component with respect to efficiency and shading. For this purpose, the surface of the tube reflector may have different radii of curvature and an asymmetry relative to the respective component. The reflector is designed as double-walled and reflects the IR radiation emitted by all components. An outer wall extending parallel to the reflector is provided on the side of the reflector opposite the reflector surface and is insulated from the reflector by an air gap. With regards to efficiency, it may be advantageous if insulation is provided between the reflector and the tube reflector. By this means, the amount of radiation reflected by the tube reflector is optimized with respect to the pure air gap insulation.
With respect to the electrical component, it may be advantageously provided that the heating element has a heating spiral which is sheathed with a metallic and/or ceramic sheath. The two materials are generally used in alternation. It has been shown that the advantage of pulse width modulation may be used for both types of heating elements, thus for those made from metal and those made from ceramic. As an alternative to a surrounding, symmetrical sheath, the heating spiral may be meander-shaped or in strips laid adjacent to one another, embedded into a metallic and/or ceramic material or sheathed by the same.
It may be advantageous for the further improvement of efficiency if insulation is also provided between the heating element and the reflector. In the case of use without a separate tube reflector, the proportion of radiation directed upward or behind the heating element is minimized by this means in favor of the proportion of radiation directed downward or forwards. This advantage may be used both for ceramic heating elements and also for heating elements with a metallic sheath. With respect to a simple design, it may be advantageous is if the heating element is mounted on the reflector. The reflector thereby functions as a supporting component, and a connection for the heating element through the reflector into a supporting housing, which is present behind the reflector, may be thus omitted.
It may be further advantageous for the pulse width modulation if the first component is designed as a dark radiator, has a burner for fuel, and has at least one exhaust gas pipe coupled to the burner and designed as a radiant tube. The exhaust gas pipe forms a very good buffer for absorbing the radiation emitted by the heating element, and the exhaust gas pipe has a very good property of redischarging or reemitting this absorbed radiation. In addition to the material property, the large surface and the large mass of an exhaust gas pipe are decisive for the advantage of being used as a buffer.
It may be advantageous for the operation of an infrared radiator with fuel if a suction fan is arranged at the end of the exhaust gas pipe so that the exhaust gas pipe connects the burner to the suction fan. The fuel does not flow freely into the exhaust gas pipe and completely combusts in the exhaust gas pipe.
It may be advantageous for a dark radiator if the exhaust gas pipe has at least one linearly-extending section or at least two linearly-extending sections coupled via a connecting tube deflecting the exhaust gas flow, wherein the linearly-extending sections are arranged on the reflector parallel to the longitudinal axis. The course of the exhaust gas pipe is largely dependent of the geometry of the flame, which is also controlled by the suction fan.
As an alternative to a dark radiator, it may be advantageous if the first component is designed as a light radiator, has at least one incandescent body, and has a connection for supplying fuel gas to the incandescent body. Such heat sinks, preferably produced from ceramic, form a very large surface for the fuel and may also have catalytic properties.
The combination of electrical components with components that are operated with fuel has the advantage that the infrared radiator only has one electrical connection which is provided to supply and/or control all components. Correspondingly, the addition of a second component does not necessitate an increase in installation costs.
It may be advantageous for a dark radiator if the reflector is placed on at least two bulkheads arranged parallel to the transverse axis, wherein the bulkheads have attaching points for suspending the infrared radiator. At the same time, the bulkheads have multiple recesses which function as mounts for the exhaust gas pipe.
It may be advantageous with regard to versatility if at least one electrical ceiling light with a light source is provided as a working light, connecting to the reflector surface in at least one direction of one of the axes or connecting to the reflector in at least one direction of one of the axes. The present installation, in the form of electrical cables and supports for the infrared radiator, may be simultaneously used for lighting due to this type of integrated ceiling light.
It may also be advantageous if the connection is designed for three-phase alternating current and the same number of heating elements and/or light sources are connected to each phase of the connection. A uniform network load is achieved in this way.
With regard to a simpler production, it may be of particular significance for the present invention if a common control unit is provided to control the two components and the two components may be selectively controlled independently from one another or simultaneously with one another.
Further advantages and details of the invention are explained in the patent claims and in the description and depicted in the figures. As shown in:
For reasons of clarity, the respectively identical components depicted in the following figures are not consistently numbered. The respective reference numeral of a certain component may be determined from the respective first figure of a certain view. These are essentially
Numerous details of an infrared radiator 1 are depicted in a sectional view in
Reflector 2 forms a hood 26, closed at the top, in which multiple components 30, 40 are arranged to generate heat in the form of infrared radiation. Air gap 10 is accessible via holes 29 in reflector 2, so that air may be extracted from hood 26 via air gap 10 and supplied to a burner 3 (
In all exemplary embodiments, a component for heating, designed as radiant tube 30, is identically positioned underneath reflector 2 for heating. Radiant tube 30 functions to supply and combust fuel gas and has two sections A1 and A2 (
A second component for heating is provided in the form of an electric resistance heater 4. This comprises three heating elements 40 extending in the direction of longitudinal axis L, which have a heating spiral 41 with a metallic sheath 42, depicted in greater detail in
Electric resistance heater 4 is arranged centered and above the two sections of radiant tube 30. Electric resistance heater 4 is thereby likewise offset in the direction of transverse axis Q with respect to radiant tube 30 as well as offset above in the vertical direction perpendicular to transverse axis Q. Due to this offset, radiant tube 30 lies in the radiation sector of heating element 40, which is depicted with dashed lines on the left side for a heating element 40 by way of example. This always creates a radiation shadow, regardless of whether radiant tube 30 is colder or warmer than heating element 40.
According to
A combination of metallic and ceramic heating elements 40 in conjunction with a dark radiator is depicted in
According to all depicted exemplary embodiments and regardless of the selection of the material for electric resistance heater 4, an offset to radiant tube 30 is provided, which according to the invention enables a simple power adjustment using pulse width modulation of the electric heating elements together with an independent assembly.
As is clear in
According to the view from below according to
In the exemplary embodiment according to
Additional exemplary embodiments are sketched in
Number | Date | Country | Kind |
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DE202021004 139.7 | Aug 2021 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2022/073657 | 8/25/2022 | WO |