EP4209712A2 - Method for detecting a blocked condensate discharge of a heating device, computer program, control device and heating device - Google Patents

Abstract

A method for detecting a blocked condensate drain (14) of a heating device (1) comprising at least the following steps: a) detecting an operating parameter that allows conclusions to be drawn about the voltage amplitude of an ionization electrode (13) of a flame detection, b) comparing the in step a) detected operating parameters with a limit value, c) detection of a blocked condensate drain (14). The invention can be used in particular for automatic detection of a blocked condensate drain (14) of a heating device (1) and is based in particular on the idea of detecting a blocked condensate drain (14 ) and the associated contact of an ionization electrode (13) with condensate via an operating parameter that enables a (direct) conclusion to be drawn about the voltage amplitude present at an ionization electrode (13) of the flame detection.

Description

The invention relates to a method for detecting a blocked condensate drain of a heating device, a computer program, a regulation and control device and a heating device.

As a rule, condensate occurs in a heating device during a combustion process (e.g. of natural gas or hydrogen). According to the prior art, the condensate collecting in a combustion chamber of the heating device is fed from the combustion chamber and the heating device to a drain through a condensate drain, often comprising a siphon.

Disadvantageously, a blocked drain or siphon can lead to significant problems. If the drain is blocked, the condensate can rise in the combustion chamber and possibly flow into the burner or possibly further into the gas supply. This can cause considerable damage to the heater and require costly repairs.

In the case of devices with flame detection based on ionization current, the ionization electrode can be arranged below the burner. If the condensate drain is blocked, the condensate could only collect up to the level of the ionization electrode, because if the ionization electrode comes into contact with the condensate, the ionization current is interrupted and the heater switches off due to the lack of flame detection. Such a solution is for example in EP 3 081 861 A1 described. However, this solution can have disadvantages not be used with hydrogen-powered heaters because a hydrogen flame does not release sufficient electrical charge carriers to detect an ionization current and therefore a collapse of the ionization current due to a ground fault of the ionization electrode due to an increased condensate level cannot be detected.

In the GB 2187 829A is proposed to prevent a blockage of a heater outlet to collect condensate arising in the heater in a container and then to empty the entire container via the drain. This is intended to reduce the risk of the process being blocked.

GB 249 7140 A proposes providing a connection piece with a switch in a condensate drain pipe, which can be activated by condensate flowing out inside the drain pipe. Through communication means, the switch can cause another switch to turn off the heater.

A particular disadvantage of these solutions is their complexity, which, in addition to an increased probability of failure, also entails increased costs for production and assembly.

Proceeding from this, it is the object of the invention to propose a method for operating a heating device which at least partially overcomes the problems of the prior art described. In particular, the method is intended to create a very simple and safe way of detecting a blockage in a (condensate) drain and preventing consequential damage.

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

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.

1. a) Erfassen eines Betriebsparameters (des Heizgeräts oder eines zugehörigen Bauteils), der einen Rückschluss auf eine (elektrische) Spannungsamplitude an einer lonisationselektrode einer Flammenerkennung ermöglicht,
2. b) Vergleichen des in Schritt a) erfassten Betriebsparameters mit einem (vorgegebenen) Grenzwert,
3. c) Erkennen eines blockierten Kondensatablaufes (aus dem Vergleich in Schritt b)).

A method for detecting a blocked condensate drain of a heater contributes to this, comprising at least the following steps:

1. a) Detection of an operating parameter (of the heater or an associated component) that allows conclusions to be drawn about an (electrical) voltage amplitude at an ionization electrode of a flame detection system,
2. b) comparing the operating parameter recorded in step a) with a (specified) limit value,
3. c) Detection of a blocked condensate drain (from the comparison in step b)).

Steps a), b) and c) can be carried out at least once in the specified sequence in a regular process sequence.

The invention can be used in particular for automatic detection of a blocked condensate drain of a heating device. A blockage of the drain would result in condensate no longer being able to drain out of the combustion chamber of the heater and accumulating in the Combustion chamber accumulates, which can lead to significant damage to the heater. The invention is based here in particular on the idea of detecting a blocked condensate drain and the associated contact of an ionization electrode with the condensate via an operating parameter that enables (immediate) conclusions to be drawn about the voltage amplitude of an ionization-based flame detection.

In principle, a method proposed here can be used in any heating device whose operation can produce a significant amount of condensate. As a primary or secondary (redundant) system, the heater can have an ionization current-based flame detection, by means of which a method described here can be carried out. Heaters that use hydrogen as a fuel may have flame detection based on the UV (ultraviolet) radiation of the flame as the primary system and may also have a redundant ionization current-based system, which may be used to carry out a method proposed here. For this purpose, the heater can have a device for ionization current-based flame detection, comprising an ionization electrode that can be positioned in or in the immediate vicinity of a flame of the heater. The device for flame detection based on ionization current can also include an (electrical) circuit with a transformer that can provide the ionization electrode with an AC voltage and a control circuit that can regulate the voltage amplitude of this AC voltage.

The heater is in particular a gas heater which is set up to burn a gaseous fuel, such as natural gas or in particular hydrogen, with the supply of ambient air, in order to provide heat, for example for a heating circuit and/or a hot water supply. The heater usually has at least one burner and a conveyor (such as a fan) that a mixture of fuel (especially a fuel gas) and combustion air through a mixture channel of the heater to the burner. The exhaust gas produced by the combustion can then be routed through an exhaust pipe of the heater to an exhaust system. In addition, the heater has a drain for the (liquid) condensate that occurs during combustion. The drain may include a siphon. The condensate can be routed to a suitable location, for example a sewer, via the drain and/or the siphon.

The drain is usually located at the (geodetically) lowest point of the combustion chamber (in the operating position) to ensure that the condensate drains off as completely as possible. The drain often includes a siphon, that is to say a U-shaped area which closes the drain in a gas-tight manner, as a result of which it is possible to prevent external air from entering the combustion chamber. A blockage of the drain is often caused by or in the siphon. A blockage of the drain can result in the same being completely closed, or also in such a reduced outflow speed that the condensate cannot drain off quickly enough and collects in the combustion chamber. A “blockage” is understood here in particular to mean that the condensate cannot flow off, or only to an insufficient extent.

According to a step a), the (preferably metrological and/or automatic) detection of an operating parameter of the heating device or a part of the heating device takes place, which makes it possible to draw conclusions about a voltage amplitude of an ionization electrode of the flame detection. The operating parameter, which allows conclusions to be drawn about the voltage amplitude of an ionization electrode of a flame detection, can be detected by measuring the voltage amplitude, for example. In an advantageous manner, a manipulated variable of the regulation for keeping the voltage present at the ionization electrode constant can be detected directly from the voltage regulation. Frequently the manipulated variable will be a PWM (pulse width modulated) signal. A known device for ionization current-based flame detection can thus be used particularly advantageously for a method presented here.

According to a step b), the operating parameter recorded in step a) is compared with a limit value. The limit value can represent a threshold value below or above which it can be assumed with certainty that the ionization electrode has come into contact with condensate and an associated (electrical) ground fault or a conductive connection between the electrode and the reference potential (typically the device ground). The limit value can be selected in particular with a view to the heating device and/or its surroundings and/or its fuel mixture or the combustion process. It is possible that the limit value is fixed; B. with regard to relevant parameters of the current combustion and / or environmental conditions can be automatically, variably determined and specified.

According to a step c), a blocked condensate drain can be recognized from the comparison from step b), in particular when the limit value is reached, fallen below or exceeded. For example, if the operating parameter recorded in step a) is a control variable for keeping the voltage applied to the ionization electrode constant, a blocked condensate drain can be detected in step c) if the control variable reaches or exceeds a limit value. If the operating parameter is the (unregulated) voltage of the ionization electrode, reaching or falling below a limit value can indicate a blocked condensate drain. The limit value can thus be determined based on the behavior of the operating parameter recorded in step a) when the ionization electrode comes into contact with condensate, for example based on tests on a reference heating device. The limit value can be stored in a memory, in particular in a memory of a regulation and control unit of the heater.

According to an advantageous embodiment, the heater can be switched off (automatically) in step d) if a blocked outlet is detected in the heater (step c)). In particular, this can result in the automatic stop of the heater burner.

According to a further advantageous embodiment, when a blocked condensate drain is detected according to step c), the heater can provide or send information about the blocked condensate drain in a step e). Advantageously, the heater can thus automatically inform an operator, user or a specialist company about the blocked condensate drain and, if necessary, a shutdown of the heater (step d)). In a particularly advantageous manner, the information can be provided or sent via a network, in particular the Internet. For example, after detecting a blocked condensate drain of the heater according to step c), the heater could automatically send information about this to a selected specialist company, which can plan and carry out a maintenance appointment to eliminate the blocked drain.

According to an advantageous embodiment, the operating parameter can be detected in step a) via a combined ignition and ionization electrode.

The method is suitable for a gas-powered heater that uses hydrogen or natural gas as fuel in particular.

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 device). In addition, one or more limit values for carrying out a method presented here can also be stored in a memory of 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 gas burner and a delivery device which can deliver a mixture of gas (especially hydrogen) and combustion air to the gas burner.

According to a further aspect, it is proposed to use an operating parameter which allows conclusions to be drawn about the voltage amplitude of an ionization electrode of a flame detection system for detecting a blocked condensate outlet of a heating device.

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

A method for detecting a blocked condensate drain of a heating device, a computer program, a storage medium, a regulation and control device, a heating device and the use of an operating parameter are thus specified here, which at least partially solve the problems described with reference to the prior art. In particular, the method, the computer program, the regulation and control unit, the heater and the use at least contribute to the reliable detection of a blockage in the condensate drain of a heater. The method can be implemented particularly advantageously without physically changing a heating device by implementing a computer program. Thus, the complexity of a heater presented here corresponds to that of a heater according to the prior art.

Fig. 1:

einen Ablauf eines hier vorgeschlagenen Verfahrens,

Fig. 2:

eine Brennkammer eines hier vorgeschlagenen Heizgerätes,

Fig. 3:

ein hier vorgeschlagenes Heizgerät,

Fig. 4:

eine schematische Darstellung eines Regelkreises zur Flammenüberwachung, und

Fig. 5:

eine schematische Darstellung eines Aufbaus einer Schaltung zur Flammenerkennung.

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:

Figure 1:

a sequence of a method proposed here,

Figure 2:

a combustion chamber of a heater proposed here,

Figure 3:

a heater proposed here,

Figure 4:

a schematic representation of a control circuit for flame monitoring, and

Figure 5:

a schematic representation of a structure of a circuit for flame detection.

1 shows an exemplary and schematic sequence of a method proposed here. The method is used to detect a blocked condensate drain 14 of a heating device 1. The sequence of steps a), b) and c) shown in blocks 110, 120 and 130 can occur in a regular operating sequence. In particular, however, carrying out steps a) to c) simultaneously (permanently) or regularly at different times may appear sensible.

In block 110, according to step a), an operating parameter is detected which allows conclusions to be drawn about the voltage amplitude of an ionization electrode 13 of a flame detection. In block 120, according to step b), the operating parameter recorded in step a) is compared with a limit value. In block 130, according to step c), a blocked condensate drain 14 of the combustion chamber 8 is detected.

2 shows a schematic example of a heater 1 proposed here. The heater 1 can have a supply of combustion air 4 to which combustion gas can be added via a gas valve 5 . The resulting combustion mixture can be fed to a burner 3 arranged in a combustion chamber 8 via a mixture channel 16 in which a conveying device 2 can be arranged. Combustion products that arise can be discharged from the combustion chamber 8 via an exhaust system 9 .

The heating device 1 can also have a regulating and control unit 7 which can be electrically connected to an ionization electrode 13 which can be electrically connected in the combustion chamber 8 below the burner 3 . In addition, the regulation and control device 7 can be electrically connected to the gas valve 5 , the delivery device 2 and an ignition device 6 . In an alternative embodiment, a combined ignition and ionization electrode can also be used. A method proposed here can advantageously be carried out on the regulating and control device 7 .

3 shows an example and schematically a combustion chamber 8 of a heater 1 proposed here. Combustion mixture can be fed to the burner 3 via the mixture channel 16 and burned with the formation of a flame 11 . The flame 11 can be monitored using a UV sensor 12, for example. The combustion chamber 8 can also have an ionization electrode 13, which is also suitable for monitoring the flame 11. UV sensor 12, burner 3 and ionization electrode 13 can be arranged in a burner door 17, as a result of which electrical wiring, for example with a regulating and control device 7, can advantageously be simplified.

In the installed state, geodetically at the lowest possible point, the combustion chamber 8 can have a condensate drain 14 which can include a siphon 15 . If the condensate drain 14 is blocked, the condensate level in the combustion chamber 8 can rise to the height of the ionization electrode 13. According to the method proposed here, the heater 1 would now use an operating parameter to draw conclusions about the voltage amplitude of the ionization electrode 13 of the flame detection if the condensate drain 14 is blocked .

According to an optional step d), the burner 3 of the heating device 1 could be switched off in step c) after a blocked condensate drain 14 was detected, thus preventing the condensate level in the combustion chamber 8 from rising further. Damage to the heating device 1, in particular to the burner 3, can thus be effectively prevented. Switching off the heating device 1 can refer in particular to shutting down the burner 3 in order to prevent further formation of condensate.

4 shows an example and a schematic of a control circuit 18 for carrying out a method presented here and figure 5 , also schematically and by way of example, a known circuit for operating an ionization current-based flame detection, the ionization electrode 13 are used simultaneously as an ignition electrode and a Ignition circuit 29 can be connected upstream. A voltage amplitude for the ionization electrode 13 is specified as a target variable 19 for a regulator 24 and feedback of the actual voltage 21 is fed via a voltage divider to an ADC (analog-to-digital converter) input of the regulator 24 and evaluated in the regulator 24 . The controller 24 can use a manipulated variable 20, here a PWM (pulse width modulated) signal, as an actuator 22 to control a switch 25 and thus an input voltage 27 transformed by a transformer 26. The AC voltage signal 23 provided by the transformer 26 and the switch 25 can be transmitted to the ignition circuit 29 via a diode 28, where the ignition circuit 29 can comprise a capacitor which is charged to the amplitude of the AC voltage signal. The AC voltage signal is applied to the ionization electrode 13 via the capacitors without a DC component.

If the ionization electrode 13 comes into contact with condensate when the condensate level in the combustion chamber 8 is rising due to a blockage of the condensate drain 14, an electrical current can flow from the ionization electrode 13 to ground due to the conductivity of the condensate, which increases the voltage at the ionization electrode 13 and thus at of the ignition circuit 29 and the ionization electrode 13 attenuates. The controller 24 detects this via the feedback of the actual voltage 21 and attempts to counteract this by changing the manipulated variable 20 in order to increase the voltage amplitude back to the specified target variable 19 .

In the example shown, the voltage at the ionization electrode 13, for example via the feedback of the actual voltage 21, or also the manipulated variable 20 of the controller 24, can be detected as an operating parameter that draws conclusions about the voltage amplitude of an ionization-based flame detection in step a).

A method presented here can advantageously be executed as a computer program on a regulation and control unit 7 presented here and a device known from the prior art for ionization current-based flame detection.

The invention can be used in particular for automatic detection of a blocked condensate drain of a heating device and is based in particular on the idea of detecting a blocked condensate drain and the associated contact of an ionization electrode with condensate via an operating parameter that allows (immediate) conclusions to be drawn about the voltage amplitude present at an ionization electrode Flame detection allows to detect.

reference list

1

heater

2

conveyor

3

burner

4

supply of combustion air

5

gas valve

6

ignition device

7

regulation and control unit

8th

combustion chamber

9

exhaust system

11

flame

12

UV sensor

13

ionization electrode

14

condensate drain

15

siphon

16

mixture channel

17

burner door

18

control loop

19

target size

20

manipulated variable

21

Actual voltage feedback

22

actuator

23

AC voltage signal

24

controller

25

Switch

26

transformer

27

input voltage

28

diode

29

ignition circuit

30

capacitors

Claims (11)

Method for detecting a blocked condensate drain (14) of a heating device (1), comprising at least the following steps: a) detecting an operating parameter of the heater, which allows conclusions to be drawn about a voltage amplitude of an ionization electrode (13) of a flame detection, b) comparing the operating parameter recorded in step a) with a limit value, c) Recognition of a blocked condensate drain (14) from the comparison according to step b). Method according to claim 1, wherein the operating parameter detected in step a) is a voltage amplitude of an AC voltage signal (23) of the ionization electrode (13) of the flame detection. Method according to claim 1 or 2, wherein the operating parameter detected in step a) is a manipulated variable (20) of a control loop (18) for keeping constant the voltage amplitude of an AC voltage signal (23) of the ionization electrode (13) of the flame detection. Method according to one of the preceding claims, wherein the operating parameter is detected in step a) via a combined ignition and ionization electrode (13). Method according to one of the preceding claims, wherein in a step d) a burner (3) of the heating device (1) is switched off when a blocked condensate outlet (14) is detected. Method according to one of the preceding claims, wherein in step e) information about a result of the comparison in step b) or about switching off the heating device (1) in step d) is provided or sent. Computer program set up to carry out a method according to one of the preceding claims. A machine-readable storage medium on which is stored a computer program according to claim 7. Regulating and control device (7), set up to carry out a method according to one of Claims 1 to 6. Heating device (1) having a regulating and control device (7) according to Claim 9. Use of an operating parameter, which allows conclusions to be drawn about the voltage amplitude of an ionization electrode (13) of a flame detector, for detecting a blocked condensate outlet (14) of a heating device (1).

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