DE102022103736A1 - Procedure for starting up a heater, computer program, regulation and control device, heater and use of a parameter - Google Patents

Abstract

A method for starting up a heater (1) is proposed, set up to supply a flow rate (10) of a mixture of fuel and combustion air to a burner (3) of the heater, wherein during the start-up of the heater (1) the burner (3) supplied flow rate (10) is detected and an irregular ignition process is detected by evaluating the detected flow rate (10).

Description

The invention relates to a method for starting up a heating device, a computer program, a regulation and control device, a heating device and the use of a parameter.

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 obtain heat for supplying a building or for providing hot water.

When such heaters are put into operation, a delivery device is generally started up to a target output and fuel is added to a delivered volume flow of intake combustion air. The combustion mixture is fed to a burner of the heater and ignited by an ignition device, for example a spark or glow igniter.

Irregularities in the supply and/or composition of the combustion mixture can cause problems here, with an excessively high proportion of fuel in the mixture composition occurring regularly and being one of the reasons that lead to so-called hard ignition. This can be expressed in an explosive noise, which can also damage the heater or its components. In addition to the loss of comfort due to noise exposure, the occurrence of hard ignition can lead to damage and is therefore relevant to safety.

According to the state of the art, the occurrence is recognized by the user and reported to a specialist company, which can carry out maintenance and inspection of the heater. If this cannot be done, for example because no one is present to identify the problem, there is a high risk of damage to the heater combined with the general safety risks of a (possibly damaged) gas system. Last but not least, the heater can try again after unsuccessful (hard) ignition, increasing the risk of damage.

The EP 3 581 850 A1 proposes to detect faulty ignition when starting a burner with the help of the control device, with a fan speed of the fan being recorded and compared with a stored and expected course of the same and faulty ignition being determined. The proposed method of a regulated blower speed appears to be difficult because it is influenced by a speed control and makes the comparison with a stored signal more difficult and delays it.

Proceeding from this, it is the object of the invention to propose a method for starting up a heating device which at least partially overcomes the problems of the prior art described. In particular, problems during commissioning should be recognized automatically and a new ignition attempt should be prevented.

In addition, the invention should at least not significantly increase the complexity of a heating device, require only minor structural changes to a heating device and enable simple integration into an existing production process.

These objects are solved by the features of the independent patent claims. Further advantageous refinements 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 meaningful manner and define further refinements of the invention. In addition, the features specified in the patent claims are specified and explained in more detail in the description, with further preferred configurations of the invention being presented.

A method for starting up a heater contributes to this, the heater being set up to supply a burner of the heater with a flow rate of a mixture of a fuel and combustion air, with the flow rate supplied being recorded during the start-up of the heater and an irregular ignition process being detected by evaluating the detected flow rate is detected.

• - einen zu hohen Anteil Brennstoff in dem, dem Brenner zugeführten Gemisch aus Brennstoff und Verbrennungsluft,
• - insbesondere also einem Lambda-Wert in einem Bereich von 1 oder (deutlich) darunter,
• - eine andere Unregelmäßigkeit in der Gaszufuhr, und/oder
• - ein verspätetes Zünden des Gemisches.

The method is used to detect an irregular ignition process of a heater, in particular a so-called "hard" ignition, i.e. an explosive ignition process, triggered in particular by:

• - too high a proportion of fuel in the mixture of fuel and combustion air fed to the burner,
• - in particular a lambda value in a range of 1 or (significantly) below,
• - another irregularity in the gas supply, and/or
• - delayed ignition of the mixture.

In particular, the method can be carried out each time a heating device is started up (every ignition process) in order to monitor it for irregularities.

The heater is, in particular, a heater that is set up to burn a liquid and/or gaseous fuel (heating oil, natural gas, hydrogen) with the supply of ambient air and thermal energy, for example to heat a heat transfer medium of a heating circuit or to provide it to generate a hot water supply. In particular, the heater can be a condensing boiler. The heater generally has a combustion chamber and a delivery device that can deliver a mixture of fuel and combustion air via a mixture channel into a combustion chamber in which a burner can be arranged. The combustion products can then be fed to an exhaust system through an exhaust duct of the heater.

The delivery device can in particular be a blower whose (delivery) performance can be specified by a speed. The performance of the conveyor is often controlled by a regulator. The controller can be a P or PI controller, for example. The delivery device can thus set a flow rate of combustion air and/or a mixture of combustion air and fuel, which can be detected via a flow sensor.

When the heater is started up, the delivery device can be started up to a (specified) suitable (target) output ((target) speed), whereby a target flow rate of combustion air or a mixture of fuel and combustion air can be promoted. As a rule, a suitable amount of fuel (for an ignition process) 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 igniter).

It is assumed that in the case of an irregular ignition process, for example an explosive phenomenon (hard ignition) during the ignition process, which propagates through the mixture duct (and exhaust duct/exhaust system) as a pressure pulse (change in pressure, pressure wave) and thus changes the flow rate (suddenly). . Even if this change only lasts for a short time, it can be recognized from the recorded flow rate. A pressure pulse can also occur during a regular ignition process, but this can be distinguished from an irregular ignition process by a quantitative consideration and/or a change in the parameter over time.

The detected flow rate can in particular be a detected mass or volume flow relating to the combustion air supplied to the burner and/or the mixture of combustion air and fuel supplied to the burner. The monitoring or regulation of the actual flow rate is advantageous compared to monitoring a fan speed because it allows influences such as (1) pressure or suction in the exhaust system due to environmental influences such as wind or air pressure etc., and/or (2) back pressures due to the type and/or or length of the flue gas pipes or other heating devices on the same shaft can be taken into account. In addition, tolerances due to pressure losses in the device components and/or tolerances in the fan and a blockage in the exhaust gas system can be compensated for.

According to an advantageous embodiment, an irregular ignition process can be assumed if the detected flow rate undergoes a (sudden) change of at least 10% [percent] during the ignition process of starting up the heater. The specific value can depend on various properties of the heating device, with the value for a regular ignition process being able to be determined in a simple manner, thus making it possible to distinguish between a regular and an irregular ignition process.

According to an advantageous embodiment, with a regulated output (speed) of the delivery device, an irregular ignition process can also be detected by considering a time period from 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 (through the regulation). 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 period of time until the control of the output of the delivery device can regulate it back to the target flow rate can be a measure of the intensity of the pressure pulse and thus limit an irregular ignition process.

According to an advantageous embodiment, the period of time can be in a range from 1 s to 3 s [seconds]. The period of time can also depend on various properties and circumstances, with the period of time also being easily ascertainable in the case of a regular ignition process and in this way a distinction can be made between a regular and an irregular ignition process in a simple manner.

According to an advantageous embodiment, after an irregular ignition process has been detected, the heater can be (automatically) taken out of operation and/or in particular (likewise automatically) renewed operation can be (automatically) prevented (blocked). For safety reasons, it can only be put into operation again by a specialist workshop or a competent person. Damage to the heater can advantageously be prevented in this way.

According to an advantageous embodiment, when or after an irregular ignition process has been detected, the output of the conveying device or the blower can be automatically adjusted such that the flow rate is brought (again) within a predetermined range. In particular, it is possible to automatically set conveying conditions suitable for the ignition process again immediately after the irregular ignition process has been detected. In this way you can (initially) avoid switching off the heater or try to stabilize the process again. The effect of the readjustment of the delivery device or the blower can also be monitored via the flow rate, for example over a predetermined readjustment period. After the readjustment period has elapsed, either normal operation or emergency operation or an emergency stop can be resumed.

According to an advantageous embodiment, information about the detection of an irregular ignition process, in particular after the automatic readjustment described above, can be displayed via a display device of the heater and/or made available for retrieval via a network, in particular the Internet, and/or as a message to be sent. For example, the information can be brought to the attention of a specialist company and/or a user/operator of the heating device on a mobile terminal device or a computer. A specialist company could then (automatically and independently) plan and carry out a maintenance appointment.

According to a further aspect, a computer program is also proposed which is set up 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 the program is executed by a computer, cause the latter to execute a method described here.

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

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

According to a further aspect, a regulation and control unit for a heating device is also proposed, set up to carry out a method presented here. For this purpose, the regulating and control unit can have a processor, for example, or have it at its disposal. In this context, the processor can, for example, execute the method stored in a memory (of the regulation and control unit). Advantageously, a regulation and control unit often regulates the output of the delivery device anyway, so that a parameter to be detected according to a method proposed here is already available to the regulation and control unit.

According to a further aspect, a heater with a closed-loop and open-loop control unit presented here is also proposed. The heater is in particular a gas heater with a burner and a delivery device that can deliver a mixture of fuel gas and combustion air to the gas burner. The heater can in particular have a flow sensor which can detect the mass or volumetric flow of combustion air and/or mixture of combustion air and fuel supplied to the burner.

According to a further aspect, the use of a parameter that allows conclusions to be drawn about a flow rate of combustion air or a mixture of combustion air and fuel supplied to the burner to detect an irregular ignition process of a heating device is proposed. According to an advantageous embodiment, the parameter can be detected in particular 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).

The details, features and advantageous configurations discussed in connection with the method can accordingly also occur in the computer program presented here, the regulation and control device, the heating device and/or the use and vice versa. In this respect, reference is made to the statements there on the more detailed characterization terization of the features are referred to in full.

A method for starting up a heating device, a computer program, a regulation and control unit, a heating device and a use are thus specified here, which at least partially solve the problems described with reference to the prior art. In particular, the procedure for starting up a heater, the computer program, the regulation and control unit, the heater and its use at least help to enable automated detection of an irregular starting process and to prevent (subsequent) renewed start-up and possible negative consequences.

In addition, the invention can be carried out with a heating device according to the prior art without structural changes and can therefore also be easily retrofitted to existing devices in the form of a software update.

• 1: ein hier vorgeschlagenes Heizgerät, und
• 2: einen Parameterverlauf, der sich bei Durchführung eines hier vorgeschlagenen Verfahrens einstellen kann.

The invention and the technical environment are explained in more detail below with reference to the attached figures. It should be pointed out that the invention should not be restricted by the exemplary embodiments given. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and findings from the present description. In particular, it should be pointed out that the figures and in particular the proportions shown are only schematic. Show it:

• 1 : a heater proposed here, and
• 2 : a parameter progression that can occur when a method proposed here is carried out.

1 shows a schematic example of a heater 1 proposed here. A conveying device 2 can be set up 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 fed to a burner 3 of the heater 1 via a mixture channel 16 . The combustion products can be discharged via an exhaust gas duct 8 of an exhaust system 9 .

A flow sensor 11 can be arranged in the combustion air feed 4 and/or in the mixture channel 16, which detects a mass or volume flow that occurs and can transmit it to a regulation and control unit 7 of the heater 1 via an electrical connection. The regulating and control unit 7 can also include a controller 6 for controlling the output of the conveying device 2 . The regulating and control unit 7 can also be electrically connected to the delivery device 2 and the gas valve 5 for regulating the heating device 1 . A display device 18 can display information about a result of a method proposed here and in particular can provide information about a switched off/blocked heating device 1 . The regulating and control device 7 can also be connected to a network 17, via which information about an (automatically) detected irregular ignition process can be made available for retrieval or sent as a message.

2 shows a parameter curve that can occur when a method presented here is carried out. in the in 2 The diagram shown shows a detected flow rate 10 as a function of time t, given in seconds, which can be, in particular, a detected signal from the flow sensor 11, a detected mass or volume flow.

When the heater 1 is started up, the flow rate 10 (given as volume flow V, for example) can be increased to a target flow rate 12 that can correspond to a target output of the delivery device 2 . After the target flow rate 12 has been reached, fuel gas can be added to the mass flow of combustion air via the gas valve 5 . Ignition 13 can then take place via an igniter. The flow rate 10 can decrease as a result of the ignition 13 due to a triggered pressure pulse, with the controller 6 attempting to reach the setpoint flow rate 12 again. After a period of time 15, the target flow rate 12 can be reached again 14.

An irregular ignition process can be recognized based on the time duration 15 and/or based on a quantitative consideration of the change (reduction) in the detected flow rate 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 plan and carry out a maintenance appointment.

Reference List

1

heater

2

conveyor

3

burner

4

supply of combustion air

5

gas valve

6

controller

7

regulation and control unit

8th

exhaust duct

9

exhaust system

10

flow rate

11

flow sensor

12

target flow rate

13

ignition

14

reaching again

15

duration

16

mixture channel

17

network

18

display device

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 3581850 A1 [0006]

Claims (12)

Method for starting up a heater (1), set up to supply a flow rate (10) of a mixture of a fuel and combustion air to a burner (3) of the heater, the flow rate (10) supplied to the burner (3) during the start-up of the heater (1) 10) is detected and an irregular ignition process is detected by evaluating the detected flow rate (10). procedure after claim 1 , The flow rate (10) being detected by a flow sensor (11). Method according to one of the preceding claims, in which the conveying device (2) is a fan. Method according to one of the preceding claims, in which an irregular ignition process is inferred if there is a sudden change in the detected flow rate (10) of more than 10%. Method according to one of the preceding claims, wherein when the heater (1) is put into operation, a target flow rate (12) is set and, to detect an irregular ignition process, a period of time (15) is used until, based on the detected flow rate (10), a renewed achievement (14 ) of the target flow rate (12) can be detected. procedure after claim 5 , the time period (15) being in a range from 1 second to 3 seconds. Method according to one of the preceding claims, wherein when an irregular ignition process is detected, the heating device (1) is taken out of operation. Method according to one of the preceding claims, wherein when an irregular ignition process is detected, information about this is displayed via a display device (18) and/or made available via a network (17) for retrieval and/or sent via the network (17) as a message. A computer program comprising instructions that cause a computer to carry out a method according to any one of the preceding claims. Regulating and control device (7), set up to carry out a method according to one of Claims 1 until 8th . Heater (1) having a regulation and control unit (7). claim 10 . Use of a detected flow rate (10) of combustion air or a mixture of combustion air and fuel fed to a burner (3) of a heating device (1) for detecting an irregular ignition process of the heating device (1).

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