METHOD FOR MONITORING A FLAME OF A HEATING APPLIANCE, HEATING APPLIANCE, COMPUTER PROGRAM AND STORAGE MEDIUM

Description

[0001] The invention relates to a method for monitoring a flame of a heating device, a computer program, a storage medium and a heating device.

[0002] Heating appliances are often equipped with a flame detection and monitoring system to detect the escape of unburned fuel gas. In addition, flame information is frequently used to control the heating appliance, particularly the composition of the combustion mixture (fuel and combustion air). This is achieved using a flame monitoring device, such as optical systems or ionization electrodes.

[0003] Heating appliances are also known to be suitable for various types of gas, such as natural gas (L-gas or H-gas), hydrogen, or liquefied petroleum gas (LPG). However, it has been shown that monitoring the flame when using a heating appliance with different types of gas presents difficulties because the position and / or formation of the flame depends on the type of fuel gas. Inaccurate or malfunctioning flame monitoring can lead to the heating appliance shutting down, resulting in a loss of comfort and costs for the operator.

[0004] JP H09 145049 A describes a method and a device in which a flame rod for monitoring a flame as a function of an oxidation state is moved axially into the flame by a drive unit.

[0005] US Patent 3,301,307 A relates to a device for detecting a flame pattern of a burner, in which an electrode is moved in the flame and a voltage curve of the electrode is detected, from which a flame pattern can be derived.

[0006] US Patent 3,059,693 A shows a direct automatic spark igniter and a safety verification system in which a thermal element expands under the influence of the heat of the flame and closes a mechanical switch, thus indicating the presence of a flame.

[0007] The aforementioned solutions are unsuitable for optical flame monitoring sensors. A disadvantage of the solutions shown, which involve an electrode positioned or moving within the flame, is the increased maintenance required, as the electrode can wear out and / or become soiled under the influence of the flame. Therefore, they are unsuitable for use in heating appliances for building supply. Furthermore, the proposed solutions are particularly suitable for single flames. Monitoring a flame field, such as that of a perforated burner plate in a heating appliance, is either impossible or extremely difficult with the devices shown. DE 296 12 014 U1 proposes a flame detection device for a gas burner flame, comprising at least two flame detection elements arranged at different distances from a burner surface.However, the use of at least two flame detection elements can result in high costs.

[0008] Based on this, the object of the invention is to propose a method for monitoring the flame of a heating appliance that at least partially overcomes the problems of the prior art described above. In particular, the method should enable the safe operation of a heating appliance with different types of fuel gas.

[0009] Furthermore, the process should be feasible without increased effort and should not significantly increase the complexity of a heating device.

[0010] These problems are solved by the features of claim 1. Further advantageous embodiments of the solution proposed here are specified in the dependent claims. In addition, the features specified in the claims are further specified and explained in the description, and further preferred embodiments of the invention are presented.

[0011] The inventive method for monitoring a flame of a heating device, comprising a flame monitoring device comprising an optical sensor, includes at least the following steps: a) Sensory detection of a flame situation using the flame monitoring device; allowing conclusions to be drawn about flame characteristics such as the position and / or the shape of the flame at the burner; b) Evaluation of the detected flame situation using a comparison or analysis unit of the heating appliance with regard to at least one flame characteristic, which includes the relative position of the flame to the burner, the height, orientation, distribution, temperature and / or color of the flame, whereby a comparison is made with predetermined, previously detected and / or previously evaluated flame characteristics of a flame situation, so that a change over time can be detected; c) Positioning of the flame monitoring device depending on the flame characteristic

[0012] The determination of the (current) flame situation is carried out using sensors. In particular, it can be determined which fuel gas and / or fuel gas-air mixture is used to generate the flame. The current flame situation allows conclusions to be drawn about the position and / or shape of the flames at the burner. These conclusions lead, in step b), to an evaluation of how pronounced one or more flame characteristics are. A flame characteristic includes the relative position of the flame to the burner, its height, orientation, distribution, temperature, and / or color, etc. Step b) involves a comparison with predefined or previously determined / evaluated flame characteristics, so that any changes in the flame characteristics over time can be detected.A flame characteristic can be assigned a predetermined or suitable position of the flame monitoring device, so that in step c) an actual position of the flame monitoring device is set depending on this flame characteristic(a).

[0013] By moving the flame monitoring device to a suitable position as described in step c), the device's functionality for monitoring the flame can be ensured. The suitable monitoring position can be specifically tailored to the type of fuel gas and the associated flame height and spread. This advantageously ensures reliable flame monitoring of a heating appliance even when operating with different types of fuel gas.

[0014] The heating appliance in question is, in particular, a gas-fired boiler designed to burn fuel gas with the addition of ambient air and to generate heat energy, for example, to heat a heat transfer fluid in a heating circuit or to provide hot water in a domestic hot water supply. Specifically, the heating appliance may be a condensing gas boiler. The heating appliance typically has a combustion chamber and a delivery system that supplies a mixture of fuel gas and combustion air to the combustion chamber. The combustion products can then be discharged through an exhaust system.

[0015] The heater is equipped with a flame monitoring device. Monitoring the flame of a heater is particularly important to prevent the escape of (unburned) fuel gas. Escaping fuel gas poses a significant health risk and an explosion hazard, among other things, which is why flame monitoring devices are legally required in most countries. Flame monitoring can be integrated into a gas burner control unit, which can also be used to regulate and control the heater.

[0016] Several methods for monitoring the flame of a heating appliance are known in the prior art. For example, an ionization electrode is frequently used, which utilizes the conductivity and rectifying effect of the flame during ignition and combustion to detect the flame, thereby also enabling an assessment of the flame quality. The ionization principle for flame monitoring is particularly common in natural gas-fired gas heating appliances.

[0017] For example, monitoring hydrogen-powered heating appliances using the ionization principle is not always simple or reliably possible because the combustion of hydrogen does not produce a sufficient ion concentration. Therefore, optical devices, especially optical sensors such as UV sensors, are primarily used to monitor the flame of hydrogen-powered heating appliances.

[0018] A suitable position can refer to the physical position (location, orientation, etc.) of a flame monitoring device relative to the flame. In particular, the suitable position can also include the orientation of the flame monitoring device, in other words, its line of sight. This can be particularly relevant for optical flame monitoring devices.

[0019] The procedure can be initiated manually, for example, during a gas conversion of a heating appliance to a different type of fuel gas. This could be done, for instance, by loosening the mechanical connection between a flame monitoring device and the heating appliance, moving the flame monitoring device to a different position, and securing it there, for example, by using a screw connection at different positions. Preferably, the positions can be marked.

[0020] In a further step d), a suitable position of the flame monitoring device can be determined. Determining a suitable position of the flame monitoring device can involve retrieving a position stored, for example, on a storage medium of the control unit.

[0021] Steps a) to d) can be executed in the specified order. It is possible for step d) to be executed before steps a) to c). It is possible for the steps to overlap or be executed in parallel, at least partially. It is possible for step a) to be executed automatically at predetermined times and / or based on a specific burner situation or a flame monitoring result.

[0022] Determining a suitable position of the flame monitoring device can consist of evaluating the monitoring by the flame monitoring device during its movement, identifying a suitable position, and recording it.

[0023] The flame monitoring device can be arranged in or on a positioning device. A positioning device can be a device with which the flame monitoring device can be moved into different positions and fixed in place. A positioning device can, for example, be designed as a rail within which the flame monitoring device is slidably arranged.

[0024] The positioning device can have a rotational mechanism, for example a (ball) joint or a hinge. Advantageously, the flame monitoring device can thus be moved and aligned by means of a translational and / or a rotational movement.

[0025] The flame monitoring device can be moved or positioned by at least one drive. This drive can be, for example, electric or hydraulic. Preferably, one drive for translational movement, such as a linear drive, and one drive for rotational movement can be provided. An automated movement of the flame monitoring device can advantageously be achieved using a single drive. For this purpose, various positions of the flame monitoring device can be stored in a memory, for example, in the control unit of the heating appliance. When required, for example, when changing the gas type, these positions can be recalled, and the flame monitoring device can be moved to the recalled position.

[0026] The positioning device can comprise a longitudinally extending element, for example a rail, on which the flame monitoring device is movable, preferably in a guide. The longitudinally extending element can have a curvature, so that by moving the flame monitoring device on the longitudinally extending element, both the position and the orientation of the flame monitoring device can advantageously be adjusted.

[0027] The flame monitoring device can be moved or positioned depending on the heating appliance's power output. Several flame characteristics, such as the position and / or extent of the flame, depend on the current power output of the heating appliance and can lead to inaccuracies in flame monitoring. This can be counteracted by positioning the flame monitoring device based on the power output. An automated repositioning of the flame monitoring device based on the heating appliance's power output can be particularly advantageous. Different positions depending on the heating appliance's power output could, for example, be stored in a memory as a characteristic curve.

[0028] A heating device according to a further aspect of the invention comprises an optical sensor of the flame monitoring device for determining a flame situation, a positioning device, a comparison and / or analysis unit for evaluating the flame situation and a control and regulating device which is suitable for carrying out the steps of the method according to the invention.

[0029] Furthermore, it can include a drive, a data storage device, data lines, electrical connections, etc.

[0030] In addition, a computer program is proposed which is configured to carry out a method presented here. In other words, this concerns a computer program (product) comprising commands which, when the program is executed by the control unit of the heating device according to the invention, cause it to execute a method described here.

[0031] Another aspect proposed is a machine-readable storage medium on which the computer program is stored. This storage medium can also contain suitable settings for different gas types and / or different heating appliance outputs, particularly in the form of a characteristic curve.

[0032] The machine-readable storage medium is usually a computer-readable data carrier.

[0033] The control unit may contain or have a processor. In this context, the processor can, for example, execute the procedure stored in a memory (of the control unit).

[0034] Advantageously, the positions of the flame monitoring devices, which are particularly suitable for different gas types or heating appliance outputs, can also be stored on a control and regulating device and / or a storage medium proposed here.

[0035] The control unit is a component of a heating appliance within a heating system. The heating appliance is, in particular, a gas-fired heating appliance with a gas burner and a conveying device that can supply a mixture of gas and combustion air (combustible mixture) to the gas burner. According to the invention, the heating appliance includes a positioning device for a flame monitoring device, with which different positions and / or orientations of the flame monitoring device can be set.

[0036] This document describes a method for monitoring the flame of a heating appliance, a computer program, and a heating appliance for carrying out the method, which at least partially solve the problems described with reference to the prior art. In particular, the method, the computer program, and the heating appliance each contribute to enabling precise and reliable monitoring of the flame of a heating appliance when using different types of fuel gas. Furthermore, adjusting the flame monitoring device to a suitable position based on the power output can enable reliable flame monitoring across the entire power range of the heating appliance.

[0037] It should be noted as a precaution that the numerical terms used here ("first", "second", etc.) primarily serve (only) to distinguish between several similar objects, quantities, or processes, and thus do not necessarily dictate any dependency and / or sequence between these objects, quantities, or processes. Should a dependency and / or sequence be required, this is explicitly stated here, or it will be obvious to a person skilled in the art upon studying the specific configuration described. Where a component can occur multiple times ("at least one"), the description of one of these components may apply equally to all or some of the multiple components, but this is not mandatory.

[0038] The invention and its technical context are explained in more detail below with reference to the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the situations described in the figures and combine them with other components and findings from the present description. It should be emphasized that the figures, and especially the depicted dimensions, are only schematic. They show: Fig. 1 : a heating system with a heating appliance as proposed here, and Fig. 2 : a burner of the heating appliance with a flame monitoring device when carrying out a procedure proposed here.

[0039] Fig. 1 Figure 1 shows an exemplary and schematic representation of a heating system 0 with a heating appliance 1 proposed here. The heating appliance 1 has a burner 3 to which a gas mixture (mixture of fuel gas and air) can be supplied via a mixture channel 11. Ambient air can be drawn in via an air intake pipe 4 and supplied with combustion gas via a gas supply pipe 8. The fuel gas can be introduced via a gas valve 5, which is electrically connected to a control and regulating device 7. A conveying device 2 can be arranged in the mixture channel 11, which can convey a mixture of fuel gas and air to the burner 3. The conveying device 2 can, for example, be designed as a blower and alternatively can also be arranged in the exhaust duct of an exhaust system 9 downstream of the burner 3. The burner 3 can be arranged in a combustion chamber 12, which can have an ignition device 6 and a flame monitoring device 10.The flame monitoring device 10 can, for example, be configured as a UV sensor, i.e., a sensor for ultraviolet light. The fuel gas can, for example, be hydrogen.

[0040] Fig. 2Figure 1 shows, also by way of example and schematically, a burner 3 which can generate a flame 17 when in operation. The burner 3 can be arranged in a burner door 13 and have an opening 15 for a flame monitoring device 10. The flame monitoring device 10 can be movably arranged in a positioning device 14. Moving (or repositioning) the flame monitoring device 10 can be accomplished, for example, by means of a drive 16, which can be designed as a linear drive. The drive 10 can move the flame monitoring device, for example, from a first position 101 to a second position 102. By moving the flame monitoring device 10, both its position and its orientation can be set. The first position 101 and second position 102 can represent suitable positions for different types of fuel gas.

[0041] According to a preferred further development, the flame monitoring device 10 can also be continuously moved between the first position 101 and the second position 102, thus enabling safe monitoring of the flame for the entire power range of the burner 3 or the heating device 1. Reference symbol list

[0042] 0 Heating system 1 Heater 2 Conveyor 3 Burner 4 Air intake pipe 5 Gas valve 6 Ignition device 7 Control and regulating unit 8 Gas supply pipe 9 Exhaust system 10 Flame monitoring device 101 First position 102 Second position 11 Mixture channel 12 Combustion chamber 13 Burner door 14 Positioning device 15 Opening 16 Drive 17 Flame

Claims

1. Method for monitoring a flame (17) of a heating appliance (1) with a flame monitoring device (10) having an optical sensor, comprising at least the following steps: a) Sensory determination of a flame situation with the flame monitoring device (10), which allows conclusions to be drawn about flame characteristics such as the position and / or formation of the flame (17) at the burner (3); b) evaluating the detected flame situation by means of a comparison and / or analysis unit of the heating appliance (1) with regard to at least one flame characteristic, which includes a relative position of the flame (17) to the burner (3), the height, the orientation, the distribution, the temperature and / or the colour of the flame (17) , whereby a comparison is made with predetermined, previously determined and / or previously evaluated flame characteristics of a flame situation, so that a change over time can be detected ; c) positioning the flame monitoring device (10) depending on the flame characteristics.

2. . Method according to claim 1, wherein in one step d) a suitable position (101, 102) of the flame monitoring device (10) is detected.

3. . Method according to one of the preceding claims, wherein the flame monitoring device (10) is moved by means of a positioning device (14) which enables translational and / or rotational movement of the flame monitoring device (10).

4. . Method according to one of the preceding claims, wherein the positioning of the flame monitoring device (10) is carried out with a drive (16).

5. . Method according to one of the preceding claims, wherein the flame monitoring device (10) can be positioned automatically.

6. . Method according to one of the preceding claims, wherein the flame monitoring device (10) is moved to a position (101, 102) depending on the output of the heating appliance (1).

7. . Heating appliance (1) with an optical flame monitoring device (10), a positioning device (14), a comparison and / or analysis unit and a control and regulation device (7) which is suitable for carrying out the steps of a method according to one of the preceding claims.

8. . Computer programme comprising commands which cause the control and regulation device (7) of the heating appliance (1) of claim 7 to execute the method steps according to one of claims 1 to 6.

9. . Machine-readable storage medium on which the computer program according to claim 8 is stored.