Method for starting up a heating device, control and control device, heating device and computer program

Abstract

A method for commissioning a heating appliance (1) is proposed. This appliance may be configured to combust a combustion mixture of combustion air and fuel gas, which is supplied to a burner (3) and ignited by an ignition device (12). The method comprises at least the following steps: a) detecting a power requirement Q for the heating appliance (1), b) selecting a suitable ignition power (29, 30, 31) of the ignition device (12) for the power requirement Q detected in step a), c) initiating an ignition process of the heating appliance (1) with the ignition power (29, 30, 31) of the ignition device (12) selected in step b). The method allows the ignition power (29, 30, 31) to be adapted to the power requirement Q of the heating appliance (1) and can thereby increase the convenience and safety of an ignition process.

Description

[0001] The invention relates to a method for commissioning a heater, a control and regulating device, a heater and a computer program.

[0002] A large number of heating devices are known which burn a mixture of a fuel, in particular gas or hydrogen, and ambient air in a combustion chamber in order to generate heat to supply a building or to provide hot water.

[0003] When such heaters are started up, a feed system is typically brought up to a desired output, and fuel is added to a conveyed volume flow of drawn-in combustion air. The resulting combustion mixture is fed to a burner of the heater and ignited by an ignition device, such as a spark igniter or glow igniter. If the supplied combustion mixture does not form a flame within a safety period, the start-up attempt is aborted. The safety period is selected so that the escape of a critical (unburned) amount of fuel gas from the burner during a start-up attempt can be reliably avoided.

[0004] Different ignition conditions, such as the heater's modulation point during the ignition process or operating parameters, can significantly influence the ignition process. Problems during the ignition process can lead to unwanted noise and, if more severe, even damage to the heater.

[0005] EP 3 301 365 A1 proposes to control the ignition operation of a heater by taking into account an operating parameter recorded before the ignition operation. The operating parameter can be suitable for representing the quality, type, or calorific value of the fuel and / or a power requirement of the heater. However, the proposed method is very complex; in particular, the determination and consideration of the operating parameter must be tailored to the heater and is therefore prone to errors.

[0006] DE 196 05 216 A1 discloses a vehicle heater for a liquid fuel, in which a control voltage of a glow plug is adjusted during a starting process depending on the supplied combustion air and the supplied fuel.

[0007] Based on this, the object of the invention is to propose a method for starting up a heating device that at least partially overcomes the problems described in the prior art. In particular, a particularly simple and universally applicable method is to be proposed.

[0008] In addition, the invention should at least not significantly increase the complexity of a heater, require only minor structural changes to a heater and enable easy integration into an existing production process.

[0009] These objects are achieved by the features of the independent patent claims. Further advantageous embodiments of the solution proposed here are specified in the independent patent claims. It is pointed out that the features listed in the dependent patent claims can be combined with one another in any technologically expedient manner and define further embodiments of the invention. Furthermore, the features specified in the patent claims are further specified and explained in the description, with further preferred embodiments of the invention being presented.

[0010] A method for commissioning a heating device contributes to this, wherein the heating device is designed to burn a combustion mixture of combustion air and fuel gas and the method comprises at least the following steps: a) detecting a power request to the heater, b) selecting a suitable power of the ignition device for the power request detected in step a), c) initiating an ignition process of the heater with the power of the ignition device selected in step b).

[0011] Steps a), b), and c) can be performed at least once in the specified sequence during regular procedure execution. In particular, steps a) to c) can be performed each time the heater is started up. This procedure ensures a safe ignition process or safe start-up of a heater and can, in particular, help reduce noise during the ignition process and prevent damage to the heater.

[0012] The heater can comprise at least one heat generator, in particular a gas condensing boiler, which releases thermal energy through the combustion of a fuel and can transfer it to a heating circuit via at least one heat exchanger, wherein consumers of the heating circuit can be connected to the heater via a heating flow and a heating return of the heating circuit. In the heater, a circulation pump in the heating circuit can be configured to circulate a heat transfer medium (heating water), wherein heat transfer medium heated via a heating flow can be supplied to consumers, such as convectors or surface heating systems, and returned to the heat generator or the at least one heat exchanger via the heating return. Exhaust gases produced during combustion can be discharged to the outside via an exhaust duct of the heater and a downstream exhaust system.

[0013] The heater can have a conveying device, in particular a fan, which can supply a mixture of combustion air and fuel (hydrogen) to a burner of the heater. The conveying device can comprise a power control, in particular a speed controller. The heater can form a pneumatic gas-air connection in which a mass flow of combustion air is added to a mass flow of combustion air according to a negative pressure (control pressure) of a throttle point, such as a Venturi nozzle, so that a predefined (specified) combustion air ratio (air ratio, lambda) can be established. Alternatively, the heater can have an electronic gas-air connection in which a signal from a flame monitor can be used to draw conclusions about the flames and the combustion air ratio (also referred to as lambda or air ratio), thus enabling control of the same.The heater can be designed, in particular, to burn hydrogen as a fuel or a mixture containing hydrogen. The mixture can have a hydrogen content of at least 80% or at least 90%.

[0014] The heater can also have flame monitoring. An ionization electrode is often used for this purpose, which can use the ionization current of the flame to detect it. However, this principle cannot be robustly applied to a hydrogen flame, as significantly fewer free charge carriers are produced during the combustion of hydrogen. Therefore, other methods are often used in hydrogen-powered heaters, such as detecting the electromagnetic radiation emitted by the flame, particularly infrared (IR) and / or UV (ultraviolet) radiation, or detecting the flame temperature. A signal from a flame monitor can indicate the presence of a flame and also allow conclusions to be drawn about the combustion air ratio of the flame.

[0015] The heater may also have an ignition device arranged on the burner in such a way that the combustion mixture emerging from the burner can be ignited. The ignition device may, in particular, be an electrical ignition device whose power is electrically controllable.

[0016] The ignition device can, in particular, be a spark igniter, where the intensity of the generated ignition spark can be adjusted by the applied electrical power. The intensity of the ignition spark, and thus the (electrical) power of the ignition device, can significantly influence the ignition process. The electrical power can be adjusted, for example, by an ignition voltage.

[0017] Alternatively, the ignition device can be a hot-surface igniter, which can be electrically heated to a surface temperature above the ignition temperature of the combustion mixture. The electrical power of a hot-surface igniter can be used to adjust its surface temperature, and thus the ignition conditions of the combustion mixture at the burner.

[0018] Commissioning a heater can proceed as follows. First, a control unit of the heater, for example, can start a delivery device, usually designed as a fan, to a specified starting power or starting speed. Subsequently, after the starting power or starting speed has been reached, a mass flow of fuel specified for the starting speed can be supplied, and an ignition process can be initiated by starting the ignition device at a specified power.

[0019] According to step a), a (current or most recently existing) power requirement for the heater can be recorded. The power requirement can, for example, be a modulation point of the heater determined by a heat requirement for the heater. For this purpose, a control unit of the heater can, for example, detect a heat requirement (measured or calculated) and determine a corresponding modulation point. The heat requirement can be detected, for example, based on recorded temperatures of the heating flow and return. The modulation point can specify a power to be modulated within a range of a minimum and a maximum power of the heater. For example, a request for hot water from the heater usually results in the selection of a modulation point that corresponds to a high power, often the maximum power, of the heater.

[0020] According to step b), a suitable ignition power can be selected for the power requirement recorded in step a). In particular, the suitable ignition power is selected in (direct) dependence on the recorded power requirement, with predefined power ranges available if necessary. For this purpose, relationships or characteristic maps determined from (laboratory) tests can be used, which assign an ignition power to the parameter recorded in step a). As a rule, the ignition power to be selected will increase with increasing power requirement.

[0021] According to step c), an ignition process of the heater's burner can now be initiated with the ignition device's power selected in step b). The combustion mixture can then be ignited at the burner by the ignition device with the power selected in step b).

[0022] According to one embodiment, several power ranges of the power requirement for the heater can be (pre-)defined, each of which is assigned a specific value or value range of the ignition device's power. The power ranges can be defined, for example, by limit values that delimit adjacent power ranges of the power requirement.

[0023] According to one design, three performance areas can be defined, namely: If the power requirement is more than 60%, 70% or 80% of the maximum power of the heat generator, an ignition device power of 60% to 80%, in particular approximately 70%, can correspond to the maximum power of the ignition device; if the power requirement is less than 40%, 30% or 20% of the maximum power of the heat generator, an ignition device power of 20% to 40%, in particular approximately 30%, can correspond to the maximum power of the ignition device; and if the power requirement is in the remaining middle range, an ignition device power of 40% to 60%, in particular approximately 50%, can correspond to the maximum power of the ignition device.

[0024] According to one embodiment, in a step d), a diagnostic parameter that allows a conclusion to be drawn about the ignition process can be recorded and evaluated during the ignition process. The diagnostic parameter can be a parameter that allows a conclusion to be drawn about a pressure curve in the flow path (combustion air supply, fuel gas supply, mixture duct, exhaust pipe or system) of the heater, for example a volume or mass flow sensor in the combustion air supply or in the mixture duct, and / or a signal from the conveyor device, in particular a speed signal or a control signal from a speed controller of the conveyor device. Alternatively or cumulatively, a signal from a flame monitor of the heater can also be used as a diagnostic parameter, for example an ionization current of the flame or a signal from an optical sensor (UV sensor) that can be directed in the direction of a flame on the burner.

[0025] An evaluation of the recorded diagnostic parameter may include a comparison with reference values or characteristic maps. The reference values or characteristic maps may have been determined in advance based on laboratory tests on a reference heater.

[0026] According to one embodiment, during a repeated execution of the method, the selection of the appropriate power of the ignition device in step b) can be adjusted according to the evaluation of an ignition process in step d). In other words, a result of the evaluation of the ignition process according to step d) can be incorporated into the selection of the power of the ignition device in step b) during a repeated execution of the method. For example, if a slow ignition process is detected, the power of the ignition device can be increased during the next execution of the method, for example, by 10% of the maximum power of the ignition device.

[0027] According to one embodiment, if a critical ignition process is detected, the heater can be placed into a fault state in which restart is blocked or can only be performed by a qualified person. A critical ignition process can be detected, for example, by exceeding a pressure limit in the heater's gas supply or by a lack of or insufficient flame formation.

[0028] According to a further embodiment, information about the result of an evaluation of the ignition process, a detected critical ignition process, or the heater entering a fault state can be displayed via a display device (external or integrated into the heater) and / or made available for retrieval via a network, in particular the Internet, and / or sent as a message. For example, the information can be made available for retrieval on an appliance interface of the heater or on a network storage device (cloud). Advantageously, for example, a user / operator of the heater and / or a specialist company can be informed about the implementation of a method proposed here via a message, and the specialist company can plan and carry out an appointment for maintenance and / or repair accordingly.In particular, this can quickly resolve a fault condition in the heater.

[0029] According to a further aspect, a computer program is also proposed, which is configured to (at least partially) carry out a method presented here. In other words, this relates in particular to a computer program (product) comprising instructions which, when executed by a computer, cause the computer to carry out a method proposed here. The computer program can be executed in particular on a control and regulation device of the heater.

[0030] According to a further aspect, a machine-readable storage medium on which the computer program is stored is also proposed.

[0031] The machine-readable storage medium is usually a computer-readable data carrier.

[0032] According to a further aspect, a control and regulating device for a heater is also proposed, configured to carry out a method proposed here. For this purpose, the control and regulating device can, for example, have and / or be equipped with a processor. In this context, the processor can, for example, execute the method stored in a memory (of the control and regulating device). For this purpose, the control and regulating device can, in particular, be electrically connected to an ignition device, a conveying device, and a flame monitor. In addition, data recorded or required within the scope of carrying out a method proposed here can be stored in a memory of the control and regulating device, for example the power requirement recorded in step a) and / or reference values and / or characteristic maps for carrying out step d).

[0033] According to a further aspect, a heating device is also proposed, configured to burn a combustion mixture of combustion air and fuel gas, which can be fed to a burner and ignited by an ignition device, and further comprising means adapted to carry out the steps of the method specified here. The means can comprise a regulating and control device. The heating device can be a gas heating device, in particular a hydrogen-powered gas heating device. The gas heating device can have a burner and a conveying device with which a mixture of fuel (hydrogen) and combustion air can be fed to the burner.

[0034] The details, features, and advantageous embodiments discussed in connection with the method can also be applied to the computer program, the control unit, and the heater presented here, and vice versa. In this respect, reference is made in full to the explanations therein for a more detailed characterization of the features.

[0035] Thus, a method for commissioning a heater, a control device, a heater, and a computer program are provided here, which at least partially solve the problems described with reference to the prior art. In particular, the method for commissioning a heater, the control device, the heater, and the computer program, as well as their use, at least contribute to enabling safe and convenient commissioning of a heater. This can advantageously reduce noise generated during the ignition process and the energy consumption of an ignition device.

[0036] In addition, the invention can be used particularly advantageously without structural changes to a heating device in the form of a software implementation.

[0037] The invention and the technical environment 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 cited. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other components and findings from the present description. In particular, it should be noted that the figures, and in particular the proportions shown, are only schematic. They show: Fig. 1 : a sequence of a procedure proposed here, Fig. 2 : a heater proposed here, and Fig. 3 und 4 : Parameter curves that can occur when carrying out a procedure proposed here.

[0038] Fig. 1 shows, by way of example and schematically, a sequence of a method proposed here. The execution of steps a), b), and c) represented by blocks 110, 120, and 130 can be performed at least once in the specified order in a regular method sequence. The method serves to increase the safety of a heater 1, in particular one operated with hydrogen or a hydrogen-containing mixture as fuel, during commissioning or an ignition process. The method enables the power of an ignition device 12 to be adapted to a power or modulation point of the heater 1.

[0039] Fig. 2 shows, by way of example and schematically, a heating device 1 proposed here. This can comprise a burner 3 arranged in a combustion chamber 8. Combustion air can be sucked in via a combustion air supply 4 by a conveying device 2, in particular designed as a fan. The conveying device 2 can be connected to a speed controller 6, which can regulate a speed n of the conveying device 2 by means of a pulse width modulated (PWM) signal. A gas valve 5 can add fuel gas from a gas supply 14 to the sucked-in air mass flow of combustion air and can comprise a safety valve and a gas control valve for controlling the mass flow of fuel gas to be added. The produced mixture of fuel gas and combustion air can flow via a mixture channel 11 to the burner 3 and be ignited there by the ignition device 12.The burner 3 may have a cylindrical shape, which may be attached by a base surface to a burner door 15 such that combustion mixture can flow from the mixture channel 11 into the burner 3. After combustion, the combustion products can be discharged to the outside via an exhaust pipe 9 of the heater 1 and an exhaust system 10.

[0040] The heater 1 proposed here can be configured, in particular, for the combustion of hydrogen. Furthermore, the heater 1 can have a flame monitoring device 13 on or in the burner door 15, which can be configured here as a sensor for UV (ultraviolet) radiation emitted by the flame.

[0041] A control and regulation device 7 can be configured to regulate the heater 1. For this purpose, it can be electrically connected, for example, to the speed controller 6, the conveyor device 2, the gas valve 5, the flame monitor 13, the ignition device 12, and a network 16 (Internet). The control and regulation device 7 can be configured to implement a method proposed here.

[0042] Fig. 3 shows three power ranges of the power requirement Q for the heater 1 and their assignment to an ignition power PZ . A first power range 21 of the power requirement Q extends from the minimum power 17 of the heater 1 up to a first limit value 19 of the power requirement Q. A second power range 22 of the power requirement Q extends from the first limit value 19 up to a second limit value 20 of the power requirement Q. A third power range 23 of the power requirement Q extends from the second limit value 20 up to a maximum power 18 of the heater 1 of the power requirement Q. The first limit value 19 can be, for example, 25% [percent] and the second limit value 75% of the maximum power 18 of the heater 1.

[0043] The power ranges 21, 22, 23 are each assigned an ignition power PZ, which can assume values ranging from a minimum ignition power 24 to a maximum ignition power 25 of the ignition device 12. Thus, the first power range 21 can be assigned a first ignition power 29, which can correspond to 30% of the maximum ignition power 25. Similarly, the second power range 22 can be assigned a second ignition power 30, which corresponds to 50% of the maximum ignition power 25, and the third power range 23 can be assigned a third ignition power 31, which can correspond to 70% of the maximum ignition power 25.

[0044] In block 110, a power requirement Q can be detected according to step a). This can be within a modulation range of the heater 1 from a minimum power 17 to a maximum power 18.

[0045] In block 120, according to step b), a power PZ of the ignition device 12 can be assigned to the power requirement Q detected in step a). In the present example, a power requirement Q can be assigned the first ignition power 29 in the first power range 21, the second ignition power 30 in the second power range 22, and the third ignition power 31 in the third power range 23.

[0046] In block 130, according to step c), an ignition process of the heater 1 can be initiated with the ignition power 29, 30, 31 selected in block 120 (step b)).

[0047] According to an optional step d), a diagnostic parameter that allows a conclusion to be drawn about the ignition process can be recorded and evaluated during the ignition process. A suitable diagnostic parameter can be, for example, a rotational speed n of the conveyor device 2. An evaluation of a recorded rotational speed curve of the conveyor device 2 during the ignition process can be carried out, for example, by observing a change in the rotational speed n triggered by the ignition process. If the change in the rotational speed exceeds a limit value, a hard ignition can be assumed.

[0048] Fig. 4shows, by way of example and schematically, a selected ignition power Pz for three implementations of a method proposed here. An ignition power of the first method run 26 can be selected by assigning the power range 21, 22, 23. By evaluating the diagnostic parameter of the ignition process, a hard ignition may have been detected. As a result, the ignition power of the second method run 27 can be reduced by 10% compared to the ignition power of the first method run 26. If a hard ignition is again detected during the second method run based on the diagnostic parameter, the ignition power of the third method run 28 can be reduced again by 10% compared to the ignition power of the second method run 27.

[0049] As a precaution, it should be noted that the numerals used here ("first", "second", ...) primarily serve (only) to distinguish between several similar objects, quantities, or processes, and therefore do not necessarily specify any interdependence and / or sequence of these objects, quantities, or processes. Should a dependence and / or sequence be required, this is explicitly stated here or will be obvious to the person skilled in the art upon studying the specifically described embodiment. To the extent that a component can occur multiple times ("at least one"), the description of one of these components may apply equally to all or part of the majority of these components, but this is not mandatory. List of reference symbols

[0050] 1 Heater 2 Conveyor system 3 Burner 4 Combustion air supply 5 Gas valve 6 Speed controller 7 Control unit 8 Combustion chamber 9 Exhaust pipe 10 Exhaust system 11 Mixture duct 12 Ignition device 13 Flame monitoring 14 Gas supply 15 Burner door 16 Network 17 Minimum power 18 Maximum power 19 First limit value 20 Second limit value 21 First power range 22 Second power range 23 Third power range 24 Minimum ignition power 25 Maximum ignition power 26 Ignition power first process run 27 Ignition power second process run 28 Ignition power third process run 29 First ignition power 30 Second ignition power 31 Third ignition power

Claims

1. Method for starting up a heating appliance (1), set up for the combustion of a combustion mixture of combustion air and combustion gas, which is supplied to a burner (3) and ignited by an ignition device (12), comprising at least the following steps: a) Detecting a power requirement Q for the heating appliance (1), b) selecting a suitable ignition power (29, 30, 31) of the ignition device (12) for the power requirement Q detected in step a), c) initiating an ignition process of the heating appliance (1) with the ignition power (29, 30, 31) of the ignition device (12) selected in step b).

2. Method according to claim 1, wherein a plurality of power ranges (21, 22, 23) of the power requirement Q for the heating appliance (1) are defined, to each of which a specific value of the ignition power (29, 30, 31) is assigned in step b).

3. The method according to claim 2, wherein three power ranges (21, 22, 23) are defined, wherein: - with a power requirement Q of less than 40% of the maximum power (25) of the heat generator, a first ignition power (29) of the ignition device of 20% to 40% of the maximum ignition power (25) is selected, - with a power requirement Q of more than 60% of the maximum power (25) of the heat generator, a third ignition power (29) of the ignition device of 60% to 80% of the maximum ignition power (25) is selected, and - with a power requirement Q in the remaining range, a second ignition power of 40% to 60% of the maximum ignition power (25) is selected.

4. Method according to one of the preceding claims, wherein, if in step a) a hot water demand is detected as power demand Q, a high ignition power of more than 60% of the maximum ignition power (25) is selected.

5. Method according to one of the preceding claims, wherein, in a step d), a diagnostic parameter which allows conclusions to be drawn about the ignition process is detected and evaluated during the ignition process.

6. Method according to claim 5, wherein the diagnostic parameter is a pressure in a flow path of the heating appliance (1), a speed of a conveying device (2) of the combustion mixture, a control signal of a speed controller (6) of the conveying device (2), and / or a signal of a flame monitor (13) of the heating appliance (1).

7. Method according to claim 5 or 6, wherein, in the case of a repeated performance of the method, the selection of the suitable ignition power in step b) is adapted in accordance with the evaluation of an ignition process in step d).

8. Method according to one of claims 5 to 7, wherein the heating appliance (1) is taken out of operation when a critical ignition process is recognised in the course of the evaluation in step d).

9. Regulating and control device (7) for a heating appliance (1), set up for the combustion of a combustion mixture of combustion air and combustion gas, which is fed to a burner (3) and ignited by an ignition device (12), wherein the regulating and control device (7) is set up to cause the heating appliance (1) to carry out the method steps according to one of claims 1 to 8.

10. Heating appliance (1), comprising a burner (3) and an ignition device (12), and arranged for the combustion of a combustion mixture of combustion air and combustion gas, which can be supplied to the burner (3) and can be ignited by the ignition device (12), and further comprising a regulating and control device (7) according to claim 9.

11. A computer program comprising instructions which, when executed by a regulating and control device of a heating appliance (1) set up for combustion of a combustion mixture of combustion air and combustion gas which is supplied to a burner (3) and ignited by an ignition device (12), cause the heating appliance (1) to carry out the method steps according to any one of claims 1 to 8.

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