Bright Radiator
By employing hydrogen as fuel and advanced combustion air and exhaust gas mixing with optical control, the bright radiator achieves efficient and virtually emission-free operation, addressing pollutant emissions in modern bright radiators.
Patent Information
- Application Number
- JP2023572176
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2021-12-10
- Filing Date
- 2022-12-06
- Publication Date
- 2024-12-05
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Modern bright radiators have high efficiency but still produce significant pollutant emissions, necessitating further reductions in harmful substances like carbon monoxide, carbon dioxide, and hydrocarbons.
The use of hydrogen as the fuel gas, angled hydrogen and combustion air flows, a reflector to define an exhaust gas chamber, and an ejector to mix combustion air and exhaust gas, along with an optical sensor to control the combustion process, ensures efficient combustion with reduced emissions.
This configuration results in virtually emission-free exhaust gases by optimizing the combustion process, minimizing carbon-containing pollutants through hydrogen combustion and precise flame control.
Smart Images
Figure 2024544808000001_ABST
Abstract
Description
[Technical field]
[0001] The invention relates to a Hellstrahler, which comprises a burner, a fan and a radiation plate acting as a radiation surface and provided with flame passages, the burner being connected to a fuel gas supply, the fan being arranged to supply combustion air to the burner and the burner being arranged to cause an isothermal glow of the radiation plate.
[0002] In the industrial and commercial sectors, infrared radiators are often used to heat production and storage areas. They generate infrared radiation that is used to generate heat. The advantage of infrared radiators over conventional heating systems is, on the one hand, that they emit their heat almost without loss. On the other hand, draft phenomena, as occur in conventional combustion systems, are avoided.
[0003] A distinction is made between bright and dark radiators. In dark radiators, heat is generated in closed tubes by the combustion of a fuel gas-air mixture, whose surface is heated by the hot gases formed and emits the heat mainly as radiation, whereas in bright radiators the fuel gas-air mixture is burned on the surface of one or more ceramic radiating plates arranged for this purpose. Natural gas or liquid gas (propane or biogas) is used as fuel gas. The name bright radiator is based on the visible combustion of the fuel gas-air mixture on the ceramic radiating plate, which becomes red-hot due to this combustion. For this purpose the ceramic radiating plate has several flame passages arranged parallel to one another and which have a recess, often conical, towards the radiating side. During combustion, flame formation takes place substantially within these recesses, which results in uniform heating of the side walls of the recesses and of the webs formed between the recesses. The ceramic radiating plates can reach temperatures of more than 950°C. The combustion exhaust gases are discharged towards the room air. Such a bright radiator is described, for example, in EP 2014980 A1.
[0004] In order to minimize the harmful substances that are produced during the combustion of fuel, there is a continuous effort to achieve an optimal stoichiometric ratio of fuel gas and air in order to achieve the most complete possible combustion with minimal harmful emissions. In modern bright radiators, very good exhaust gas values have already been achieved, in particular by adapting the fuel gas and / or air to the burner. Furthermore, DE 10 2014 019 766 A1 describes a bright radiator which uses a sensor to determine the combustion value of the fuel gas and adjusts the supply of combustion air according to the optimal mixture ratio for this combustion value (closed loop control).
[0005] Modern bright radiators have proven to have a high efficiency and at the same time a relatively low emission of harmful substances. The problem underlying the present invention is to provide a bright radiator with at least the same efficiency, but with an even lower emission of harmful substances. According to the present invention, this problem is solved by the features of claim 1.
[0006] According to the present invention, a bright radiator is provided that has at least the same efficiency as the prior art and has reduced harmful emissions. The fuel gas supply is preferably connected exclusively to a hydrogen source, so that the exhaust gas theoretically contains no carbon-containing harmful substances such as carbon monoxide, carbon dioxide or hydrocarbons, because hydrogen does not contain carbon.
[0007] In a refinement of the invention, the hydrogen supply and the fan are configured and oriented such that the hydrogen flow and the combustion air flow are angled with respect to each other at an angle, preferably less than 90 degrees and greater than 45 degrees, thereby achieving good mixing of the hydrogen and the combustion air.
[0008] In the configuration of the present invention, a reflector is arranged, which surrounds the radiation surface of the radiation plate and defines an exhaust gas chamber. A combustion air mixing chamber is arranged upstream of the burner, which is connected to a combustion air source and to the exhaust gas chamber. By feeding the exhaust gas to the combustion air, oxygen reduction is achieved, which allows a reduction in the flame temperature. Furthermore, the recirculation of the exhaust gas leads to a reduction in nitrogen oxide emissions.
[0009] In another embodiment of the invention, the exhaust gas chamber is connected to the combustion air mixing chamber via an ejector, the driving medium of which is the combustion air introduced by the fan, and the medium drawn into the combustion air mixing chamber is the exhaust gas present in the exhaust gas chamber, thereby achieving a defined ratio of combustion air to exhaust gas. An actuator is preferably provided, via which the ratio of the combustion air volume flow rate to the drawn-in exhaust gas volume flow rate of the ejector can be adjusted.
[0010] In a further development of the invention, a combustion air mixing chamber is arranged inside the fan, as a result of which good mixing of the combustion air with the exhaust gases occurs.
[0011] In the present invention, the hydrogen supply is guided in an area through a distribution plate, which is arranged parallel to and spaced apart from the radiation plate and defines a fuel mixing chamber. This avoids flame backflow and at the same time produces a uniform and area-like hydrogen-combustion air mixture. Advantageously, the fuel gas supply can be connected to a source of hydrogen-combustion air mixture, in which case the hydrogen concentration in the mixture is provided above the upper explosion limit, so that the hydrogen-combustion air mixture is not ignitable. This requires only a very low oxygen content in the combustion air introduced into the mixing chamber.
[0012] In another embodiment of the invention, an intake duct is arranged at least partially surrounding the distributor plate and connected to a fan. The intake duct is preferably designed so that the combustion air flows in an area over the distributor plate, so that a uniform mixture of the combustion air with the hydrogen flowing through the distributor plate is achieved.
[0013] According to a further development of the invention, an optical sensor is provided, which is adapted to detect at least one parameter of the flame generated by the burner. Advantageously, the sensor is a UV sensor. This allows flame detection of the invisible hydrogen flame to be achieved.
[0014] In the configuration of the present invention, the optical sensor is oriented towards the radiation plate, preferably at an obtuse angle therewith, thereby achieving reliable flame detection.
[0015] In another embodiment of the invention, a reflector is arranged at least partially surrounding the radiation plate, the reflector having a window, and the optical sensor is directed from the outside of the reflector through the window towards the radiation plate, thereby achieving flame detection in a position that protects the sensor against heat.
[0016] In a refinement of the invention, the optical sensor is connected to an actuator connected to the fan for interrupting and / or regulating the combustion air supply. Preferably, the optical sensor is connected to an actuator connected to the fuel gas supply for interrupting and / or regulating the hydrogen supply. This makes it possible to influence the combustion air / hydrogen mixture or to cut off the hydrogen supply depending on the flame conditions.
[0017] In one aspect of the present invention, the actuator is connected to a control and regulation module that is programmed to adjust the flame characteristics by varying the amount of hydrogen and / or the amount of combustion air per stored target parameters.
[0018] Further refinements and configurations of the invention are defined in the remaining dependent claims. Exemplary embodiments of the invention are shown in the drawings and are explained in more detail below. [Brief description of the drawings]
[0019] [Figure 1] FIG. 2 is a schematic diagram showing a bright radiator. [Diagram 2] FIG. 13 is a schematic diagram showing a bright radiator in another embodiment. [Diagram 3] FIG. 11 is a schematic diagram showing a bright radiator in a third embodiment. [Figure 4] FIG. 10 is a schematic diagram showing a fourth embodiment of a bright radiator, including a distribution plate and a radiation plate.
[0020] The bright radiator shown in Figure 1, chosen as an example, includes a burner 1 connected to a hydrogen supply 2 and a fan 3. A reflector 4 is arranged to surround the burner 1.
[0021] The burner 1 comprises a fuel mixing chamber 11, which is delimited by a ceramic radiator plate 12. In a known manner, the ceramic radiator plate 12 is provided with a hole pattern extending over its entire surface, which is formed by a number of cylindrical flame passages which are formed with a conical expansion on the outwardly facing side of the radiator plate 12. A hydrogen supply 2 is arranged opposite the radiator plate 12 and perpendicular to the radiator plate 12. The hydrogen supply 2 opens into the fuel mixing chamber 11. A discharge line 31 connected to a fan 3 opens into the fuel mixing chamber 11 at a right angle to the hydrogen supply 2.
[0022] The fan 3 is connected on its suction side to an ejector 32, the drive connection of which is connected to a combustion air supply 33 and the suction connection of which is connected to an exhaust gas supply line 34. The exhaust gas supply line 34 is guided through the reflector. A recirculation throttle 35 is arranged in the exhaust gas supply line 34. The combustion air flow sucked in by the fan 3 through the combustion air supply 33 serves as the driving medium, by which a part of the exhaust gas padding 381 in the reflector 4 is sucked in through the recirculation throttle 35. By means of the recirculation throttle 35, the proportion of the exhaust gas flow in the combustion air flow can be adjusted, which in turn determines the oxygen content of the exhaust gas-combustion air flow mixture. The remaining exhaust gas flow passes from the reflector 4 into the surrounding air. A combustion air mixing chamber 39 is integrated in the fan 3.
[0023] On the discharge side, the fuel mixing chamber 11 is supplied with an exhaust gas / combustion air mixture by means of a fan 3. After this exhaust gas / combustion air mixture has flowed out through the radiant plate 12 together with a hydrogen flow introduced by the hydrogen supply 2, it is ignited by an ignition electrode 13 arranged outside the burner 1 in front of the radiant plate 12, so that a flame is formed on the outside of the radiant plate 12. The combustion takes place essentially in a conically expanded section of the flame passage of the radiant plate 12, so that the radiant plate 12 is heated to glowing on its outer surface. The flame temperature can be adjusted by the oxygen content of the exhaust gas / combustion air mixture, which can be adjusted via the recirculation throttle 35.
[0024] In the exemplary embodiment shown in FIG. 2, the burner 1 is designed corresponding to the preceding exemplary embodiment and is likewise surrounded by a reflector 4. Opposite the radiation plate 12 of the burner 1, likewise perpendicular to the radiation plate 12, is arranged a hydrogen supply 2 which opens into the fuel mixing chamber 11. A discharge line 31 connected to the fan 3 opens into the mixing chamber perpendicular to the hydrogen supply 2. In contrast to the above-mentioned exemplary embodiment, the fan 3 is connected on the suction side to the combustion air supply and an ejector 36 is inserted in the discharge line 31 inside the reflector 4, which forms a suction gap 37 which radially surrounds the discharge line 31. The section of the discharge line 31 following the ejector 36 forms a combustion air mixing chamber 39.
[0025] The exhaust gas flow 38 is sucked in through the exhaust gas padding 381 formed inside the reflector 4 by the combustion air flow introduced into the discharge line 31 via the fan 3 via the suction gap 37 and mixed with the combustion air flow. The exhaust gas-combustion air mixture leaving the combustion air mixing chamber 39 of the discharge line 31 is mixed in the fuel mixing chamber 11 with the hydrogen flow introduced by the hydrogen supply 2 and, after leaving through the radiation plate 12, is ignited by the ignition electrode 13 arranged outside the burner 1 and in front of the radiation plate 12.
[0026] In the exemplary embodiment shown in FIG. 3, a sensor receptacle 41 is processed in the reflector 4. The sensor receptacle has a window 42. A UV sensor 43 is introduced in the sensor receptacle, which is connected via an electrical line 44 to an actuating device (not shown) for interrupting the hydrogen supply. The UV sensor 43 is oriented at an angle of 45° to the radiation plate 12 in this exemplary embodiment. If no flame is detected by the UV sensor 43, the actuating device interrupts the hydrogen supply. The actuating device or a control and regulating module connected to the actuating device can additionally be connected to the ignition electrode 13, and can be configured in such a way that if no flame is detected, the ignition electrode 13 is first actuated and the hydrogen supply is only interrupted if the flame remains out.
[0027] In the embodiment shown in FIG. 4, a burner 5 is arranged which is also connected to the fan 3. The burner 5 comprises a fuel mixing chamber 51 which is defined by a ceramic radiator plate 52. Opposite the radiator plate 52 and perpendicular to the radiator plate 52, a hydrogen supply 2 is arranged which opens into the fuel mixing chamber 51. Between the hydrogen supply 2 and the radiator plate 52, parallel to the radiator plate 52, a distribution plate 53 is arranged. The distribution plate 53 is provided with a surface-like hole pattern formed by cylindrical perforations. The hydrogen supply 2 is connected to the distribution plate 53 via a hood-shaped section 21, so that hydrogen flows through the distribution plate 53 surface-like.
[0028] An air intake passage 54 is disposed between the distribution plate 53 and the radiator plate 52 surrounding the fuel mixing chamber 51 and has a nozzle 55 oriented in an imaginary plane angled parallel to the distribution plate 53. The air intake passage 54 is connected to and is supplied by the fan 3.
[0029] On its suction side, the fan 3 is connected to an ejector 32 according to the first embodiment, the drive connection of which is connected to a combustion air supply 33 and the suction connection of which is connected to an exhaust gas supply line 34 passing through the reflector 4. A recirculation throttle 35 is arranged in the exhaust gas supply line 34. In this embodiment, the combustion air drawn in by the fan 3 through the combustion air supply 33 also serves as the driving medium, by which a part of the exhaust gas padding 381 in the reflector 4 is drawn in through the recirculation throttle 35. By means of the recirculation throttle 35, the proportion of the exhaust gas flow in the combustion air flow can also be adjusted in this embodiment, so that the oxygen content of the exhaust gas-combustion air flow mixture is also determined. The remaining exhaust gas flow flows from the reflector 4 into the surrounding air. In this embodiment, the combustion air mixing chamber 39 is also integrated in the fan 3.
[0030] On the discharge side, the fuel mixing chamber 51 is supplied with an exhaust gas-combustion air mixture by the fan 3 via an intake passage 54. This exhaust gas-combustion air mixture flows in an area over the distribution plate 53, is mixed with the hydrogen flowing through the distribution plate 53 and is then ignited by an ignition electrode 13 arranged in the fuel mixing chamber 51. The passages of the radiating plate 52 are passed by the hot combustion exhaust gases and are thus brought to the required temperature.
[0031] The distribution plate 53 is cooled by the planar flow of the exhaust gas-combustion air mixture formed across the distribution plate 53 by the air supply passages 54. This prevents flame backflow through the distribution plate 53.
Claims
1. A bright radiator comprising a burner (1, 5), a fan (3) and a radiation plate (12) with a number of flame passages acting as a radiation surface, the burner (1, 5) being connected to a fuel gas supply, the fan (3) being configured to supply combustion air to the burner (1, 5), and the burner (1, 5) being configured to cause a surface glow of the radiation plate (12, 52), A bright radiator, characterized in that the fuel gas supply unit is connected to a hydrogen source as a fuel gas source.
2. 2. The bright radiator according to claim 1, characterized in that the hydrogen supply (2) and the fan (3) are configured and oriented such that the hydrogen flow and the combustion air flow are angled at a predetermined angle to each other, said angle being preferably less than 90 degrees and greater than 45 degrees.
3. 3. A bright radiator according to claim 1 or 2, characterized in that a reflector (4) is arranged, which surrounds the radiation surface of the radiation plate (12, 52) and defines an exhaust gas chamber, and upstream of the burner (1, 5) a combustion air mixing chamber (39) is arranged which is connected to a combustion air source and to the exhaust gas chamber.
4. 4. The bright radiator according to claim 3, characterized in that the exhaust gas chamber is connected to the combustion air mixing chamber (39) via an ejector (32, 36), the driving medium of the ejector (32, 36) is the combustion air introduced by the fan (3), and the medium drawn into the combustion air mixing chamber (39) is the exhaust gas in the exhaust gas chamber.
5. 5. The bright radiator according to claim 4, further comprising an actuator (35) via which the ratio of the combustion air volume flow rate to the intake exhaust gas volume flow rate of the ejectors (32, 36) can be adjusted.
6. 6. Bright radiator according to claim 3, characterized in that the combustion air mixing chamber (39) is arranged in the fan (3).
7. 7. The bright radiator according to claim 1, wherein the hydrogen supply is guided in a planar manner through a distribution plate (53), which is arranged parallel to and spaced apart from the radiation plate (52) and defines a fuel mixing chamber (51).
8. 8. The bright radiator according to claim 7, characterized in that an air intake passage (54) is arranged at least partially surrounding the distribution plate (53), the air intake passage (54) being connected to the fan (3).
9. 9. The bright radiator according to claim 8, wherein the intake passage (54) is configured so that the combustion air flows in a planar manner across the distribution plate (53).
10. 10. Bright radiator according to any one of claims 1 to 9, characterized in that an optical sensor is arranged, which is configured to detect at least one parameter of the flame generated by the burner (1).
11. Bright radiator according to claim 10, characterized in that said optical sensor is a UV sensor (43).
12. Bright radiator according to claim 11, characterized in that the optical sensor is oriented towards the radiation plate (12), preferably at an obtuse angle with the radiation plate (12).
13. 13. The bright radiator according to claim 10, characterized in that a reflector (4) is arranged at least partially surrounding the radiation plate (12), the reflector (4) having a window (42), and the optical sensor is directed from outside the reflector (4) through the window (42) towards the radiation plate (12).
14. 14. Bright radiator according to any one of claims 10 to 13, characterized in that the optical sensor is connected to an actuator connected to the fan (3) for interrupting and / or adjusting the combustion air supply and / or the optical sensor is connected to an actuator connected to the fuel gas supply for interrupting and / or adjusting the hydrogen supply.
15. 15. The bright radiator according to claim 14, characterized in that the actuator is connected to a control and regulation module, which is programmed to adjust the flame characteristics by changing the amount of hydrogen and / or the amount of fuel and air per stored target parameters.