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

Abstract

A method is proposed for detecting an irregular ignition process of a heating appliance (1), designed to supply a burner (3) of the heating appliance with a flow rate (10) of a mixture of fuel and combustion air, wherein during the commissioning of the heating appliance (1) the flow rate (10) supplied to the burner (3) is recorded and an irregular ignition process is detected by evaluating the recorded flow rate (10), wherein a target flow rate (12) is set during commissioning of the heating appliance (1) and a time period (15) is used to detect an irregular ignition process until a renewed attainment (14) of the target flow rate (12) can be recognized based on the recorded flow rate (10).

Description

[0001] The invention relates to a method for detecting an irregular ignition process of a heating device, a computer program, a control and regulation device, a heating device and, not the subject of the patent claims, a use of a parameter.

[0002] A variety of heating appliances are known that burn a mixture of a fuel, especially gas or hydrogen, and ambient air in a combustion chamber to generate heat for supplying a building or for providing hot water.

[0003] When commissioning such heating appliances, a conveying system is typically brought up to a set output, and fuel is added to a conveyed volume of drawn-in combustion air. The combustion mixture is then fed to a burner within the heating appliance and ignited by an ignition device, such as a spark or glow plug.

[0004] Irregularities in the fuel supply and / or composition of the combustion mixture can lead to problems, with an excessively high fuel content in the mixture being a common cause and one of the reasons for what is known as hard ignition. This can manifest as an explosive noise and may also result in damage to the heating appliance or its components. In addition to the reduced comfort due to the noise, hard ignition can therefore cause damage and thus pose a safety risk.

[0005] According to current best practices, the user should recognize the problem and report it to a qualified technician who can then service and inspect the heating appliance. If this is not possible, for example, because no one is present to detect the problem, there is a high risk of damage to the heating appliance, along with the general safety risks associated with a (potentially damaged) gas system. Furthermore, after an unsuccessful (hard) ignition attempt, the heating appliance may try to ignite again, further increasing the risk of damage.

[0006] EP 3 581 850 A1 proposes detecting a faulty ignition during burner start-up using the control device. This involves recording the blower speed and comparing it to a stored and expected profile, thus identifying a faulty ignition. The proposed method of using a regulated blower speed appears problematic because it is influenced by the speed control system, complicating and delaying the comparison with a stored signal.

[0007] DE 696 14 230 T2 relates to a combustion control system in which a signal from a flow detector for combustion air or combustion gas is detected during ignition and evaluated by means of a combustion control system to determine whether the ignition was normal or abnormal. A disadvantage is that a change in the flow detector signal can also be caused by effects other than irregular ignition, and the method therefore offers only limited reliability.

[0008] EP 3 396 248 A1 describes a diagnostic method for detecting faults in a gas safety valve. This method uses the signal from a sensor in the air supply duct. The signal can also be used to determine whether ignition was successful if the gas burner control unit did not recognize the flame. However, the method does not allow for a sufficiently precise detection of irregular ignition processes.

[0009] DE 696 14 230 T2 discloses a system for controlling combustion that can determine whether a combustion state is normal or abnormal. This system uses the signal from a flow detector. The system can include a period from the start of ignition until the detection of a rapid decrease in flow rate, which occurs during normal combustion. However, this method cannot precisely detect an irregular ignition process.

[0010] Based on this, the object of the invention is to propose a method for commissioning a heating device that at least partially overcomes the problems of the prior art described above. In particular, problems during commissioning should be detected automatically and a further ignition attempt prevented.

[0011] Furthermore, the invention should not significantly increase the complexity of a heating device, should require only minor structural changes to a heating device, and should allow for easy integration into an existing production process.

[0012] These problems are solved by the features of the independent claims. Further advantageous embodiments of the solution proposed here are specified in the dependent claims. It should be noted that the features listed in the dependent claims can be combined with one another in any technologically meaningful way and define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, which also presents further preferred embodiments of the invention.

[0013] This is achieved by a method for detecting an irregular ignition process of a heating device, wherein the heating device is configured to supply a flow rate of a mixture of fuel and combustion air to a burner of the heating device, wherein the supplied flow rate is recorded during the commissioning of the heating device and an irregular ignition process is detected by evaluating the recorded flow rate, and wherein a target flow rate is set during commissioning of the heating device and a time period is used to detect an irregular ignition process, from a deviation of the recorded flow rate from the set target flow rate until the target flow rate can be reached again based on the recorded flow rate.

[0014] The method serves to detect an irregular ignition process of a heating device, in particular a so-called "hard" ignition, i.e. an explosive ignition process, especially triggered by: an excessively high proportion of fuel in the mixture of fuel and combustion air supplied to the burner, in particular a lambda value in the range of 1 or (significantly) below, another irregularity in the gas supply, and / or a delayed ignition of the mixture.

[0015] The procedure can be carried out in particular during each commissioning (each ignition process) of a heating device in order to monitor it for irregularities.

[0016] The heating appliance in question is specifically a heating device designed to burn a liquid and / or gaseous fuel (heating oil, natural gas, hydrogen) with the addition of ambient air and to generate thermal energy, for example, to heat a heat transfer fluid in a heating circuit or to provide hot water. In particular, the heating appliance may be a condensing boiler. The heating appliance typically has a combustion chamber and a conveying system that feeds a mixture of fuel and combustion air through a mixture channel into a combustion chamber, in which a burner may be located. The combustion products can then be discharged through an exhaust duct of the heating appliance into a flue system.

[0017] The conveying device can be, in particular, a blower whose (conveying) capacity can be specified by its rotational speed. The conveying device's capacity is often regulated by a controller. The controller can, for example, be a proportional (P) or variable-speed (PL) controller. The conveying device can thus regulate the flow rate of combustion air and / or a mixture of combustion air and fuel, which can be detected by a flow sensor.

[0018] When the heating appliance is started up, the conveying system can be set to a suitable (predefined) output ((predefined) speed), thereby delivering a target flow rate of combustion air or a mixture of fuel and combustion air. Typically, a suitable quantity of fuel (for ignition) is added to a mass flow of combustion air. In the case of a gaseous fuel, this can be supplied via a gas valve. The fuel-combustion air mixture can then be ignited by an igniter (spark igniter, glow plug).

[0019] It is assumed that during an irregular ignition process, such as an explosive event (hard ignition), a pressure pulse (pressure change, pressure wave) propagates through the mixture channel (and exhaust channel / exhaust system) and thus abruptly changes the flow rate. Even if this change is only brief, it can be detected based on the measured flow rate. A pressure pulse can also occur during a regular ignition process, but this can be distinguished from an irregular ignition process by quantitative analysis and / or by measuring the parameter's temporal change.

[0020] The measured flow rate can refer in particular to a measured mass or volume flow rate of the combustion air supplied to the burner and / or the combustion air-fuel mixture supplied to the burner. Monitoring and controlling the actual flow rate is advantageous compared to monitoring a fan speed because it allows for the consideration of influences such as (1) pressure or suction in the exhaust system due to environmental factors like wind or air pressure, etc., and / or (2) back pressures caused by the type and / or length of the exhaust pipes or other heating appliances on the same flue. Furthermore, tolerances due to pressure losses in the appliance components and / or fan tolerances, as well as blockages in the exhaust system, can be compensated for.

[0021] According to one embodiment, a change in the measured flow rate during the ignition process of the heating appliance can also be included. For example, a (sudden) change of at least 10% can be relevant. The specific value can depend on various characteristics of the heating appliance, whereby the value for a regular ignition process can be easily determined, thus enabling a distinction between regular and irregular ignition processes. This can advantageously allow for the detection of component defects. For instance, the combination of change and duration could indicate a defect in the blower or the exhaust system (flue, exhaust duct). This defect could have been caused by a delayed ignition.

[0022] Thus, with a regulated output (speed) of the conveying device, an irregular ignition process can be detected according to the invention by observing the time period between a deviation of the (detected) flow rate from the set target flow rate suitable for the ignition process, until the target flow rate is reached again (by the control system). In other words, as described above, a pressure pulse triggered by an irregular ignition process can cause a change in the target flow rate, and the time period until the control system can regulate the output of the conveying device back to the target flow rate can be a measure of the intensity of the pressure pulse and thus distinguish an irregular ignition process.

[0023] According to an advantageous embodiment, the time period can range from 1 s to 3 s [seconds]. The time period can also depend on various properties and conditions, whereby even in the case of a regular ignition process, the time period can be easily determined, thus allowing a simple distinction between a regular and an irregular ignition process.

[0024] According to an advantageous embodiment, after the detection of an irregular ignition process, the heating device can be (automatically) shut down and / or, in particular, (also automatically) restarted (automatically) prevented (blocked). For safety reasons, restarting can only be permitted by a specialist workshop or a qualified person. This advantageously prevents damage to the heating device.

[0025] According to an advantageous embodiment, upon or after the detection of an irregular ignition process, the output of the conveying device or blower can be automatically adjusted so that the flow rate is (re)brought back into a predetermined range. In particular, it is possible to automatically restore suitable conveying conditions for ignition immediately after the detection of an irregular ignition process. In this way, a shutdown of the heating device can (initially) be avoided, or an attempt can be made to stabilize the process. The effect of the adjustment of the conveying device or blower can be further monitored via the flow rate, for example, over a predetermined adjustment period. After the adjustment period has elapsed, the system can then either return to normal operation or switch to emergency operation or an emergency stop.

[0026] According to an advantageous embodiment, information about the detection of an irregular ignition process, particularly after the automatic readjustment described above, can be displayed on a display device of the heating appliance and / or made available for retrieval via a network, especially the internet, and / or sent as a message. For example, the information can thus be made available to a specialist company and / or a user / operator of the heating appliance on a mobile device or computer. A specialist company could then (automatically and independently) schedule and carry out a maintenance appointment.

[0027] Another aspect is the proposal for a computer program designed to (at least partially) execute the procedure presented here. In other words, this specifically concerns a computer program (product) comprising instructions that, when executed by a computer, cause it to carry out the procedure described here.

[0028] Another aspect that is proposed is a machine-readable storage medium on which the computer program is stored.

[0029] The machine-readable storage medium is usually a computer-readable data carrier.

[0030] Another aspect is the proposal for a control unit for a heating device, designed to carry out the procedure presented here. This control unit can, for example, include or be equipped with a processor. In this context, the processor can, for instance, execute the procedure stored in the control unit's memory. Advantageously, a control unit often already regulates the output of the conveying device, so that a parameter to be acquired according to the proposed procedure is already available to the control unit.

[0031] Another aspect is the proposal for a heating appliance with a control unit as presented here. This heating appliance is specifically a gas-fired unit with a burner and a delivery system that supplies a mixture of fuel gas and combustion air to the burner. The heating appliance features a flow sensor that can detect the mass or volume flow of combustion air and / or the mixture of combustion air and fuel supplied to the burner.

[0032] According to a further aspect, which is not itself the subject of the appended patent claims, the use of a parameter that allows conclusions to be drawn about the flow rate of combustion air or a mixture of combustion air and fuel supplied to the burner is proposed for detecting an irregular ignition process of a heating appliance. According to an advantageous embodiment, the parameter can, in particular, be detected by a flow sensor and can also be a time period from a deviation from a (set) target flow rate until the target flow rate is reached again after the ignition process (by the control system).

[0033] The details, features, and advantageous configurations discussed in connection with the process may also occur in the computer program, control unit, heating device, and / or application presented here, and vice versa. In this respect, full reference is made to the explanations provided therein for a more detailed characterization of the features.

[0034] This document describes a method for commissioning a heating appliance, a computer program, a control and monitoring device, a heating appliance, and its application, which at least partially solve the problems described with reference to the state of the art. In particular, the method for commissioning a heating appliance, the computer program, the control and monitoring device, the heating appliance, and its application contribute, at least in part, to enabling the automated detection of an irregular start-up process and preventing (subsequent) restarts and potential negative consequences.

[0035] Furthermore, the invention can be implemented with a heating device according to the prior art without any structural modifications and can therefore also be easily retrofitted to existing devices in the form of a software update.

[0036] 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 device proposed here, and Fig. 2: a parameter profile that can be achieved when carrying out a procedure proposed here.

[0037] Fig. 1 Figure 1 shows an exemplary and schematic representation of a heating appliance 1 proposed here. A conveying device 2 can be configured to draw in a mass flow of combustion air via a combustion air supply 4, to which fuel gas can be added via a gas valve 5. The mixture of combustion air and fuel gas can be supplied to a burner 3 of the heating appliance 1 via a mixture channel 16. The combustion products can be discharged via an exhaust gas channel 8 into an exhaust system 9.

[0038] A flow sensor 11 can be arranged in the combustion air supply 4 and / or in the mixture channel 16. This sensor detects any mass or volume flow and transmits it via an electrical connection to a control unit 7 of the heater 1. The control unit 7 can also include a controller 6 for regulating the output of the pump 2. Furthermore, the control unit 7 can be electrically connected to the pump 2 and the gas valve 5 for controlling the heater 1. A display unit 18 can show information about the result of a procedure proposed herein and, in particular, indicate whether the heater 1 is switched off or blocked. The control unit 7 can also be connected to a network 17, through which information about an (automatically) detected irregular ignition process can be made available for retrieval or sent as a message.

[0039] Fig. 2 shows a parameter curve that can occur when carrying out a procedure presented here. In the Fig. 2 The diagram shown depicts a recorded flow rate 10 as a function of time t, given in seconds, which can in particular be a recorded signal from the flow sensor 11, a recorded mass or volume flow.

[0040] When the heating device 1 is started up, the flow rate 10 (for example, given as volume flow V) can be increased to a target flow rate 12, which can correspond to a target output of the pumping device 2. After reaching the target flow rate 12, combustion air can be added to the mass flow via the gas valve 5. Subsequently, ignition 13 can occur via an igniter. Ignition 13 causes the flow rate 10 to decrease due to a triggered pressure pulse, whereby the controller 6 attempts to reach the target flow rate 12 again. After a time period 15, the target flow rate 12 can be reached again 14.

[0041] An irregular ignition process can be detected based on the time durations 15 and 10. By providing information about a detected irregular ignition process via the display device 18 and / or via a network 17 for retrieval and / or by sending a notification, a specialist company can automatically and independently schedule and carry out a maintenance appointment.

[0042] Additionally, a quantitative analysis of the change (reduction) in the recorded flow rate 10 can be included, for example to verify the detection of irregular ignition or to identify component defects. Reference symbol list

[0043] 1 Heating unit 2 Conveyor 3 Burner 4 Combustion air supply 5 Gas valve 6 Regulator 7 Control unit 8 Exhaust duct 9 Exhaust system 10 Flow rate 11 Flow sensor 12 Target flow rate 13 Ignition 14 Re-achievement 15 Duration 16 Mixture channel 17 Network 18 Display unit

Claims

1. Method for detecting irregular ignition of a heating appliance ( ) (1) designed to supply a burner (3) of the heating appliance with a flow rate (10) of a mixture of fuel and combustion air, wherein during start-up of the heating appliance (1) the flow rate (10) supplied to the burner (3) is detected and an irregular ignition process is detected by evaluating the detected flow rate (10), wherein a target flow rate (12) is set when the heating appliance (1) is started up and a time period (15) is used to detect an irregular ignition process, whereby, if there is a deviation of the detected flow rate (10) from the set target flow rate (12) , it can be detected when the target flow rate (12) is reached again (14) based on the detected flow rate (10) .

2. Method according to claim 1, wherein the flow rate (10) is detected by a flow sensor (11).

3. Method according to one of the preceding claims, wherein the conveying device (2) is a blower.

4. Method according to one of the preceding claims, wherein a sudden change in the detected flow rate (10) of more than 10% is additionally included and evaluated.

5. Method according to one of the preceding claims, wherein the time duration (15) is in a range from 1 second to 3 seconds.

6. Method according to one of the preceding claims, wherein the heating appliance (1) is taken out of operation when an irregular ignition process is detected.

7. Method according to one of the preceding claims, wherein, upon detection of an irregular ignition process, information thereabout is displayed via a display device (18) and / or made available for retrieval via a network (17) and / or sent as a message via the network (17).

8. Control and regulating device (7) for a heating appliance (1), wherein the heating appliance (1) is designed to combust a mixture of combustion air and fuel, which is supplied to a burner (3) of the heating appliance (1) is supplied and ignited by an ignition device, and has a flow sensor (11) for detecting a flow rate of the mixture, wherein the control and regulation device (7) is designed to cause the heating appliance (1) to carry out the process steps according to one of claims 1 to 7.

9. Heating appliance (1) comprising a burner (3), an ignition device and a flow sensor (11) arranged to combust a mixture of combustion air and fuel which is supplied to the burner (3) and ignited by the ignition device, wherein the flow sensor (11) is arranged to detect a flow rate of the mixture, further comprising a control and regulation device (7) according to claim 8.

10. Computer programme comprising commands which, when executed on the control and regulation device (7) of the heating appliance (1) according to claim 9, cause the method according to one of claims 1-7 to be carried out.

Images