EP3896340B1 - Method for detecting a current or imminent blockage of at least one flow path - Google Patents

Description

The invention relates to a method for detecting an existing or impending blockage of at least one flow path that fluidly connects a heater installed in a building with the environment outside the building, a computer program for carrying out the method, a machine-readable storage medium and a heater for a building and a system including the heater. The invention can contribute in particular to the detection of an at least partially blocked or clogged exhaust and/or supply air pipe, chimney or chimney. Furthermore, the reason for the blockage, such as icing or a bird's nest building, can also advantageously be determined. The invention can therefore be used advantageously to avoid device failures caused, for example, by icing up the exhaust gas and/or supply air duct or building bird's nests.

If the exhaust gas and/or supply air path of gas condensing boilers becomes blocked or icy, they must, according to the state of the art, switch to a controlled locking fault shutdown. In this case, the user of the heater usually has no heating or hot water available until a repair is carried out. This usually happens abruptly and without warning to the user.

From the EP 3 260 777 A1 A generic method for detecting a blockage of an exhaust gas discharge of a burner system, in which at least one pressure characteristic value for detecting the blockage is recorded and/or evaluated, is known.

From the DE 10 2005 011 021 A1 is a method for adapting the device heating output of a fan-assisted heater to the individual Pressure losses in a fresh air exhaust pipe system are known. From the US 6,401,708 B1 a pressure sensor device for a gas oven is known.

It is therefore the object of the invention to at least partially solve the problems mentioned with reference to the prior art or to provide a method by means of which the operational readiness of a heater can be improved. In particular, a blockage or icing of the flow path, which could lead to an abrupt shutdown of the heater, and in particular its cause should be able to be identified as early and/or reliably as possible.

This task is achieved using a method according to the features of claim 1. Advantageous refinements result from the features of the dependent claims.

1. a) Erfassen mindestens eines Maßes für die Durchströmung des Strömungswegs,
2. b) Auswerten des in Schritt a) erfassten mindestens einen Maßes, wobei ein Vergleich mit Referenzdaten für eine freie Durchströmung des Strömungswegs erfolgt,
3. c) Veranlassen zumindest einer Warnung oder einer Beeinflussung des Betriebs des Heizgeräts, wenn aus der Auswertung gemäß Schritt b) auf eine vorliegende oder drohende Blockade des Strömungswegs geschlossen werden kann; wobei weiterhin mindestens ein Maß für die Umgebungstemperatur erfasst und ausgewertet wird und/oder mindestens ein Maß für die Luftfeuchtigkeit in der Umgebung erfasst und ausgewertet wird, und wobei, wenn aus der Auswertung gemäß Schritt b) auf eine vorliegende oder drohende Blockade des Strömungswegs geschlossen werden kann, der Grund für die vorliegende oder drohende Blockade unter Verwendung des Maßes für die Umgebungstemperatur und/oder für die Luftfeuchtigkeit in der Umgebung bestimmt wird.

A method for detecting an existing or impending blockage of at least one flow path that fluidly connects a heater installed in a building with the environment outside the building contributes to this, comprising at least the following steps:

1. a) recording at least one measure of the flow through the flow path,
2. b) evaluating the at least one measurement recorded in step a), whereby a comparison is made with reference data for a free flow through the flow path,
3. c) causing at least a warning or an influence on the operation of the heater if the evaluation according to step b) can be used to conclude that there is a current or impending blockage of the flow path; wherein furthermore at least one measure of the ambient temperature is recorded and evaluated and / or at least one measure of the air humidity in the environment is recorded and evaluated, and where, if the evaluation according to step b) indicates an existing or impending Blockage of the flow path can be closed, the reason for the existing or impending blockage is determined using the measure for the ambient temperature and / or for the air humidity in the environment.

To carry out the method, steps a) to c) can, for example, be carried out at least once in the specified order. Furthermore, steps a) and b) can also be repeated (multiple times) or steps a) and b) can start repeatedly (in the manner of a loop) with step a) before step c) is carried out. At least parts of steps a) to c), in particular steps a) and b) can be carried out at least partially in parallel or simultaneously.

The method advantageously enables the operational readiness of a heater to be improved by, for example, a (at least partial) blockage or icing of the flow path, in particular an exhaust gas and/or supply air path, which could lead to an abrupt shutdown of the heater, and in particular the cause can also be identified as quickly and/or reliably as possible. Early detection of an impending blockage contributes in particular to preventing locking fault shutdowns due to a blockage in the flow path, e.g. B. caused by at least partial blockage (e.g. by building a bird's nest) or icing of the flow path can be avoided if possible. Reliably identifying the cause of a blockage can help ensure that the heater can return to regular operation as quickly as possible after the cause has been eliminated.

The heater is usually a heater for a building. Furthermore, the heater can be, for example, a gas heater. In other words, this applies in particular to a heater that is set up to do so or to burn several fossil fuels such as liquefied petroleum gas and/or natural gas, possibly with the supply of ambient air from a building or the surrounding area, to provide energy for heating, for example, water for use in an apartment in the building and/or a water circuit for heating the building or a part of it. For example, the heater can be a so-called gas condensing boiler. The heater usually has at least one burner and a conveyor device, such as a fan, which conveys a mixture of fuel (gas) and combustion air (through a mixture channel of the heater) to the burner.

The exhaust gas resulting from combustion can then be led through an (internal) exhaust pipe of the heater to an exhaust system (of the building or system). If necessary, several heating devices can also be connected to a (common) exhaust system. The at least one flow path can be, for example, a supply air path (or supply air flow path) and/or an exhaust gas path (or exhaust gas flow path). The flow can be, for example, a supply air flow and/or exhaust gas flow.

The supply air path can, for example, include at least part of an (internal) supply air pipe of the heater and/or at least part of a supply air system (of the building or the system). The supply air path can, for example, open at one end or at one of two ends at a mixing point (for mixing fuel and air) and/or a mixture channel of the heater. The supply air path can, for example, open at another end or at the other of two ends in the environment outside the building. The supply air path serves in particular to enable a (sufficient) supply of air from the environment to the heater, in which it can usually be used as combustion air in the burner.

The exhaust path can, for example, include at least part of an (internal) exhaust pipe of the heater and/or at least part of an exhaust system (of the building or the system). The supply air path can at least partially surround the exhaust gas path (coaxially). In other words, this can also be described in such a way that the supply air path and the exhaust gas path are formed at least in sections by two separate channels in a common pipe, which is usually arranged between the heater and the environment (for example in the case of an at least partially combined exhaust and Supply air system). Thus, the supply air system and the exhaust system can, for example, be designed at least in sections as a combined system. An area of the flow path that is particularly susceptible to existing or impending blockages of the flow path is in particular the end of the flow path or the supply air and/or exhaust system that opens into the environment. This area is often formed by the chimney or the section of the supply air and/or exhaust system outside the building.

In principle, the building can be a residential building and/or a commercial building. The heater can be used in particular to heat only or at least part of the building, such as a single apartment or a single room. Alternatively or cumulatively, the heater can also be used to heat a water system (heating water circuit) of the building or an apartment. Alternatively or cumulatively, the heater can also be used to heat drinking water or service water in the building.

A blockage is present in particular when a (flow-through) cross-sectional area of the flow path is reduced or narrowed to such an extent that there is a sufficient supply of air from the environment to the heater and/or a Sufficient removal of exhaust gas(es) from the heater into the environment can no longer be guaranteed. Such a blockage of the flow path occurs in particular when the flow path (at least in a section, such as a section of a supply air and/or exhaust system external to the building, for example formed in a chimney) is already completely or almost completely blocked. An impending blockage occurs in particular if there is a fear of future blockage of the flow path. In this context, an impending blockage can be concluded in particular when a reduction in the (throughputable) cross-sectional area of the flow path begins and/or increases.

In step a), at least one measure of the flow through the flow path is recorded. The measure for the flow through the flow path can be, for example, a (flow) pressure (such as an exhaust gas pressure and/or a supply air pressure), in particular a pressure in the heater, a differential pressure (in particular between the ambient pressure and the flow pressure or Pressure in the heater), a (flow) mass flow and/or a (flow) volume flow (in particular measured in the heater). The detection is usually carried out using sensors, in particular via at least one sensor of the heater or via at least one sensor arranged in the heater. For example, the detection can take place via a sensor of the heater that can be brought into contact with the flow, such as a supply air flow and/or an exhaust gas flow. One or more sensors can be used. One sensor can be assigned to a supply air path and another sensor to an exhaust gas path. However, it can (alternatively) also be provided that a common sensor is assigned to the supply air path and the exhaust gas path. Furthermore, if necessary (for example if a differential pressure is to be determined), an ambient pressure sensor external to the heater can be used. The detection can alternatively or cumulatively also be done with at least one sensor System, comprising the heater and at least part of the exhaust system and / or at least part of the supply air system. The sensor can, for example, be assigned to the exhaust system or the supply air system, in particular be arranged in or on the exhaust system or the supply air system. If several sensors are used, for example one sensor can be assigned to the exhaust system and another sensor to the supply air system and/or arranged in or on it. The at least one sensor can, for example, be (in each case) a pressure sensor, differential pressure sensor, mass flow sensor and/or volume flow sensor. Various of these sensors can also be used.

In step b), the at least one measurement recorded in step a) is evaluated, with a comparison being made with reference data for a free flow through the flow path. The reference data can, for example, represent or describe a free flow through the flow path. The free flow can represent or describe a state of the flow path without blockage or contamination of the flow path or at least a state in which there is a sufficient supply of air from the environment to the heater and/or a sufficient removal of exhaust gas(es) from it heater into the environment can be guaranteed. The evaluation can be carried out, for example, by a control unit of the heater. The evaluation can, for example, include monitoring (continuously or repeated at time intervals) of the at least one measure.

In step c), at least a warning or an influence on the operation of the heater is initiated if it can be concluded from the evaluation according to step b) that there is a current or impending blockage of the flow path. The warning can be sent, for example, via a display on the heater and/or via a radio connection to a mobile device (such as a smartphone). a user of the heater and/or to a service provider for monitoring and/or maintenance of the heater. Influencing the operation of the heater may include, for example, restricting the operation of the heater and/or switching the heater to a defrosting mode. For example, it can be concluded that there is a blockage in the flow path if a difference between the reference data (or a reference value for the free flow) and the recorded measure of the flow through the flow path is greater than a (predefined) maximum permissible threshold value. Furthermore, for example, an impending blockage of the flow path can be concluded if a difference between the reference data (or a reference value for the free flow) and the recorded measure of the flow through the flow path is greater than a (predefined) threshold value which is in the Rule is below the maximum permissible threshold.

According to an advantageous embodiment variant, the method and in particular step c) relates to (supply air and/or exhaust gas) volume flow monitoring for gas condensing boilers to detect an existing or impending blockage and/or icing of the (supply air and/or exhaust gas) flow path. In particular, abrupt and/or locking fault shutdowns, which usually require recommissioning by qualified personnel, can advantageously be avoided as far as possible by using additional sensors and the logical combination of the (sensor) signals provided, for example by issuing a warning message at an early stage or appropriate countermeasures can be initiated.

According to an advantageous embodiment, it is proposed that the detection according to step a) is carried out using at least one sensor of the heater. This sensor can be, for example, a pressure sensor, differential pressure sensor, Act as a mass flow sensor and/or volume flow sensor. If necessary, several of these sensors can also be used in order to be able to measure, for example, several (different) measures of the flow through the flow path and/or a measure of the flow through a supply air path and (if necessary even simultaneously) a measure of the flow through an exhaust gas path.

According to a further advantageous embodiment, it is proposed that the detection according to step a) is carried out under a specific operating condition of a conveyor device of the heater. The specific operating condition of the conveyor device can, for example, be a specific speed of a fan representing the conveyor device. The detection under the specific operating condition can advantageously contribute to the fact that the recorded measure of the flow through the flow path can be compared as easily as possible with reference data which also relate to the specific operating condition or which were also determined under the specific operating condition.

According to a further advantageous embodiment, it is proposed that at least one measure of the ambient temperature is also recorded and evaluated. The measure of the ambient temperature is preferably a measured ambient temperature. The ambient temperature can be measured, for example, by a temperature sensor external to the heater and/or external to the building. The measure of the ambient temperature can be included in the evaluation according to step b) and/or can also be evaluated (with) in step b). For example, the reference data can include temperature-dependent reference values. The measure of the ambient temperature can alternatively or cumulatively be incorporated into step c) in such a way that the type of warning or influence on the operation of the heater depends on the ambient temperature.

According to a further advantageous embodiment, it is proposed that at least one measure of the air humidity in the environment is also recorded and evaluated. The measure of the humidity in the environment is preferably a measured humidity in the environment. The humidity can be measured, for example, by an (air) humidity sensor external to the heater and/or external to the building. The measure of the air humidity in the environment can be included in the evaluation according to step b) and/or can also be evaluated (with) in step b). For example, the reference data can include moisture-dependent reference values. The measure of the air humidity can alternatively or cumulatively be incorporated into step c) in such a way that the type of warning or influence on the operation of the heater depends on the air humidity in the environment.

According to a further advantageous embodiment, it is proposed that if an existing or impending blockage of the flow path can be concluded from the evaluation according to step b), the reason for the existing or impending blockage is determined using the measure for the ambient temperature and/or the measure for the air humidity in the environment is determined or limited. The determination or limitation of the reason can in particular include determining whether the existing or impending blockage is due to icing of the flow path or ice formation in the flow path. For example, if it is concluded that there is a blockage in the flow path at ambient temperatures below a predefinable temperature limit (such as 5 ° C), it can be determined, for example, that the flow path is blocked due to icing. If, for example, an impending blockage of the flow path is concluded at outside temperatures below a predefinable temperature limit, it can be determined, for example, that there is a threat of a blockage of the flow path due to ice formation. If icing and/or ice formation has been determined as the reason, For example, heating measures can be initiated that can advantageously counteract an abrupt and/or locking fault shutdown. As a heating measure, the heater can be switched to a defrosting mode, for example. Alternatively or cumulatively, if, for example, with ambient air humidity above a predefinable humidity limit (such as 60%), it is concluded that there is a blockage or an impending blockage of the flow path, it can be determined, for example, that a blockage of the flow path due to icing is present or is imminent due to ice formation . The supply air path is particularly susceptible to icing or ice formation, so that under appropriate conditions it can be determined in particular that a supply air path is blocked due to icing or is at risk of ice formation. In particular, if the supply air path at least partially surrounds an exhaust gas path, an increased and/or warmer flow through the exhaust gas path can be used in deicing mode, for example. In contrast, if, for example, at ambient temperatures above a pre-definable temperature limit and/or air humidity in the environment below a pre-definable humidity limit, it is concluded that there is a blockage or an impending blockage of the flow path, it can be determined, for example, that there is or is a threat of blockage of the flow path, which is not the case is not based on icing or ice formation, but can, for example, be traced back to the building of a bird's nest. The exhaust gas path is particularly susceptible to such blockages, so that under appropriate conditions it can be determined in particular that a blockage of an exhaust gas path is present or imminent, which is not due to icing or ice formation, but can be traced back to a bird's nest building, for example.

According to a further advantageous embodiment, it is proposed that an impending blockage is concluded if it emerges from time-spaced detection processes according to step a) that the recorded measure for the Flow through the flow path changes in the same direction from detection process to detection process. In this context, for example, several (different) (intermediate) threshold values can be (pre-)defined (which are generally below the maximum permissible threshold value), and when they are exceeded (successively or successively), this can advantageously be reliably concluded It can be assumed that there is a gradual reduction in the (flow-through) cross section of the flow path and thus there is a risk of a blockage.

According to a further advantageous embodiment, it is proposed that at least part of the reference data for the evaluation according to step b) be determined during operation of the heater with an inactive burner. In other words, this means in particular that the reference data relates to a flow of air. This advantageously contributes to the fact that (initial) reference data can be recorded during the commissioning of the heater and in particular before the burner is commissioned, whereby influence of the reference data by soot can be avoided as much as possible.

According to a further aspect, a computer program for carrying out a method described here is also proposed. In other words, this applies in particular to a computer program (product) comprising commands which, when the program is executed by a control device of a heater, cause it to carry out a method described here.

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

According to a further aspect, a heater for a building is also proposed, wherein the heater is set up to carry out a method described here. For this purpose, the heater includes a control device which is set up to carry out the method. By way of example, the control device can include a processor (controller) that can execute at least part of the method. For this purpose, the processor can, for example, execute the computer program, for which the processor can access the storage medium. For this purpose, the storage medium can represent a component of the control device or can be connectable to it. Furthermore, the heating device can comprise a corresponding sensor system for carrying out the method, such as a sensor for detecting the measure of the flow through the flow path and/or a sensor for detecting the measure of the ambient temperature, and/or a sensor for detecting the measure of the Read in humidity in the environment or data from the corresponding sensors (e.g. from an external temperature sensor and/or humidity sensor).

According to a further aspect, a system (for a building) is also proposed, comprising a heater described here and at least part of an exhaust system that can be connected to the heater and / or at least part of a supply air system that can be connected to the heater. The exhaust system and the supply air system can, for example, be components of an at least partially combined exhaust and supply air system.

The details, features and advantageous configurations discussed in connection with the method can also occur in the computer program presented here, the storage medium, the heater and/or the system and vice versa. In this respect, full reference is made to the statements there regarding the more detailed characterization of the features.

The invention will now be explained in detail with reference to the figures.

• Figur 1: schematisch ein Ablaufdiagramm zur Veranschaulichung eines Ausführungsbeispiels des hier beschriebenen Verfahrens, und
• Figur 2: schematisch ein beispielhaftes Heizgerät zur Durchführung des Verfahrens.

They represent:

• Figure 1 : schematically a flow chart to illustrate an exemplary embodiment of the method described here, and
• Figure 2 : Schematic of an exemplary heating device for carrying out the process.

Figure 1 schematically shows a flowchart to illustrate an exemplary embodiment of the method described here. The method is used to detect an existing or impending blockage of at least one flow path 2 (cf. Fig. 2 ), which fluidly connects a heater 1, which is installed in a building 3, to the environment outside the building 3. The sequence of steps a), b) and c) shown with blocks 110, 120 and 130 is exemplary and can thus be carried out in a regular operating procedure.

In block 110, according to step a), at least one measure for the flow through the flow path 2 is recorded. In block 120, according to step b), the at least one measure recorded in step a) is evaluated, with a comparison with reference data for a free flow through the Flow path 2 takes place. In block 130, according to step c), at least one warning or an influence on the operation of the heater 1 is initiated if the evaluation according to step b) can be used to conclude that there is a current or impending blockage of the flow path 2.

Figure 2 shows schematically an exemplary heater 1 for a building 3, the heater 1 being set up to carry out the method described here. The process is explained here using the exhaust gas path as an example. However, it can also be applied to the supply air route accordingly (alternatively or cumulatively). The flow path 2 is here, for example, at least partially (also) formed by an exhaust system. The heater 2 and the exhaust system (and/or a supply air system) can in particular form a (related) system.

In Fig. 2 It is illustrated that the measurement of the flow through the flow path 2 can be carried out, for example, by means of a sensor 4 of the heater 2. The sensor 4 is, for example, a volume flow sensor. Alternatively or cumulatively, a mass flow sensor and/or (differential) pressure sensor can also be used as sensor 4.

Furthermore, the measurement of the amount of flow through the flow path 2 can be carried out under a specific operating condition of a conveyor device 6 of the heater 1. The specific operating condition of the conveyor device 6 can, for example, be a specific speed of a fan representing the conveyor device 6. The detection under the specific operating condition can advantageously contribute to the fact that the recorded measure of the flow through the flow path 2 can be compared as easily as possible with reference data, which also relate to the specific operating condition or which were also determined under the specific operating condition.

In this context, an exemplary reference measurement for obtaining the reference data can proceed as follows: First, this can be done here For example, fans representing the conveyor device 6 are controlled or brought to a defined speed (specific operating condition), such as approximately 6,000 rpm. The burner is usually out of operation. Therefore only the air conveyed by the fan flows. The volume flow is then recorded using the sensor system mentioned (sensor 4) and the value pair (speed - volume flow) is saved in, for example, the device electronics. This also represents an example of how at least part of the reference data for the evaluation according to step b) can be determined while the heater 1 is operating with an inactive burner.

In addition, at least one measure of the ambient temperature, such as the ambient temperature itself, and/or a measure of the air humidity in the environment can be recorded and evaluated. For illustrative purposes in this context, Fig. 2 a temperature sensor and/or humidity sensor 5 is entered. Thus, for example, the outside temperature can also be determined via an outside temperature sensor and/or the outside air humidity via an outside air humidity sensor and included in the detection process. If a measure of the ambient temperature and/or humidity is also recorded and evaluated or is to be included in the detection process, the outside temperature and/or humidity can also be recorded via the connected temperature sensor or temperature sensor and/or during the previously described reference measurement. or air humidity sensor or air humidity sensor 5. In this context, for example, the value pair (speed - volume flow) can be expanded to include the temperature and/or humidity and/or determined and saved depending on the temperature and/or humidity.

As part of the evaluation according to step b), monitoring of the amount of flow through the flow path 2 and/or the amount of Ambient temperature and/or humidity can be carried out. For monitoring purposes, for example, measurement can be carried out continuously or at defined time intervals (e.g. before or after every xth burner cycle, after x hours of operation or after x hours) using the existing sensors (e.g. volume flow sensor 4 and temperature and/or humidity sensor 5) and a logical linking of the (measuring) signals provided takes place. Furthermore, a comparison of the measured values with the reference values can be carried out. The evaluation is carried out here, for example, by a control unit 7 of the heater 1.

If it can be concluded from the evaluation or monitoring that there is an existing or impending blockage of the flow path 2, for example because the difference between the specified reference value and the measured value is greater than a previously defined threshold value, the reason for this can also be based on this or impending blockage can be determined or limited using the measure of the ambient temperature and/or humidity in the area. In this context, for example, the threshold value can be linked in combination with the temperature signal and/or humidity signal for evaluation. On this basis, for example, the conclusions explained below can be drawn.

For example, it can be concluded that there is a blockage (existing blockage) in the flow path 2 (here, for example, the exhaust pipe) if an evaluation detects that a difference between the reference data and the recorded measure of the flow through the flow path 2 is greater than a predefined, maximum permissible threshold value. If this is at a comparatively low outside temperature (for example in the range or below 0 ° C), for example at outside temperatures below a predefinable temperature limit and / or at air humidity in the If the environment happens above a predefinable humidity limit, it can be concluded from the combination of this information that the flow path 2 is blocked by icing. If this is at comparatively normal or elevated outside temperatures (for example in the range or above 20°C) or at outside temperatures (for example above 5°C or 10°C) and/or air humidity (<60%) at which no icing is to be expected has happened, for example at outside temperatures below a pre-definable temperature limit and/or at ambient air humidity below a pre-definable air humidity limit, it can be concluded from the combination of this information that there is a blockage in the flow path 2, which is (probably) not due to icing . Corresponding blockages can be caused, for example, by a bird's nest or contamination of the exhaust pipe by soot. If it has been concluded that there is a blockage due to icing, heating measures can, for example, be initiated to eliminate the icing. During appropriate defrosting, the operation of the heater 1 can be restricted in order to avoid damage to the heater 1 and/or the ingress of exhaust gas into the building 3 as far as possible. For example, the heater 1 can be operated in a defrosting mode as a heating measure. Appropriate defrosting can advantageously help ensure that a locking fault shutdown of the heater 1 is not necessary. If it has been concluded that a blockage is not due to icing, the operation of the heater 1 can, for example, be restricted until the cause of the blockage has been eliminated. The successful or sufficient elimination of the cause of the blockage or icing can be verified, for example, by a subsequent or renewed measurement of the degree of flow through the flow path 2 in order to enable the regular operation of the heater 1 again. This can also contribute advantageously to a Locking fault shutdown of the heater 1, which usually requires repair and subsequent approval by qualified personnel, should be avoided if possible.

For example, it can be concluded that there is an impending blockage (partial blockage or slowly increasing blockage) of the flow path 2 if an evaluation detects that a difference between the reference data and the recorded measure of the flow through the flow path 2 exists and is in particular larger as a predefined threshold (which is usually below the maximum allowable threshold). If this happens at a comparatively low outside temperature (for example in the range or below 0 ° C) and / or high humidity, it can be concluded from the combination of this information that there is a risk of the flow path 2 becoming blocked due to ice formation. If this is at comparatively normal or elevated outside temperatures (for example in the range or above 20°C) or at outside temperatures (for example above 5°C or 10°C) and/or air humidity (<60%) at which no icing is to be expected has happened, it can be concluded from the combination of this information that there is a risk of blockage of flow path 2, which is (probably) not due to ice formation. Corresponding blockages can be caused, for example, by building a bird's nest or (increasing) contamination of the exhaust pipe with soot. If it has been concluded that a blockage is imminent due to ice formation, heating measures can be initiated, for example, to counteract the ice formation. During such a measure, the operation of the heater 1 can generally be continued without restrictions or with comparatively small restrictions, so that in particular an abrupt (locking) fault shutdown can advantageously be avoided. If it has been concluded that a blockage is not imminent due to ice formation or icing, a warning of an impending blockage can, for example, be sent to a user or a service provider of the heater 1 (e.g. via a display on the heater or through a notification on the user's smartphone or to a service provider). This can also advantageously help to avoid an abrupt (locking) shutdown of the heater if possible.

If an existing blockage or an impending blockage (for example a slowly clogging exhaust pipe) is detected or not detected, one of the following information can be provided, for example, via a display integrated in and/or on the heater (not shown here) or via a smartphone app solution are provided for the user of the heater 1: display of an OK signal, display of a warning signal for a slowly clogging exhaust pipe, or that the operation of the heater 1 is restricted. If after attempting to eliminate the cause of the blockage or icing (e.g. after operating the heater 1 in de-icing mode) and/or after restricting the operation of the heater 1 via a subsequent or renewed measurement of the flow rate through the flow path 2 cannot be verified that the flow path 2 is sufficiently free again, a controlled locking fault shutdown of the heater 1 can be initiated. This can also be displayed via the display or the app.

Furthermore, a conclusion can be drawn about an impending blockage if it emerges from time-spaced detection processes according to step a) that the detected measure of the flow through the flow path 2 changes in the same direction from detection process to detection process. This can be used advantageously to find faults and/or trigger triggers in the case of an exhaust pipe that is slowly becoming dirty. For example, several (different) (intermediate) threshold values can be (pre-)defined (which are usually below the maximum permissible threshold value), at which (successive or successive) If this is exceeded, it can be assumed that there is gradual contamination of the flow path 2 and/or there is a threat of a blockage due to increasing contamination of the flow path 2. When an (intermediate) threshold value is reached, a service message or warning may be triggered. When a final threshold value or the maximum permissible threshold value is reached or exceeded, a controlled shutdown can be carried out and, if necessary, a service message or warning indicating this can be triggered.

With the method described, an abrupt locking fault shutdown can be advantageously prevented, particularly in the event of a blockage of the exhaust gas path of a (gas) heater that builds up over time or is imminent, by detecting a change in the exhaust gas volume flow or the pressure loss in the exhaust gas path with the help of sensors ( e.g. mass flow, differential pressure and/or volume flow sensor) is determined and evaluated in relation to, in particular, a previously defined reference value.

A method is thus provided by means of which the operational readiness of a heater can be improved. In particular, a blockage or icing of the flow path, which could lead to an abrupt shutdown of the heater, and in particular its cause can be identified as quickly and/or reliably as possible.

Reference symbol list

1

heater

2

flow path

3

Building

4

Volume flow sensor

5

Temperature and/or humidity sensor

6

funding facility

7

Control unit

Claims (12)

1. Method for detecting an existing or imminent blockage of at least one flow path (2) which fluidically connects a heater (1) installed in a building (3) to the environment outside the building (3), comprising at least the following steps:

   a) recording at least one measurement for the flow through the flow path (2),

   b) evaluating the at least one measurement recorded in step a), wherein a comparison is made with reference data for a free flow through the flow path (2),

   c) initiating at least one warning or influencing the operation of the heater (1) if it can be concluded from the evaluation according to step b) that there is an existing or imminent blockage of the flow path (2);

   characterised in that furthermore at least one measurement for the ambient temperature is recorded and evaluated and/or at least one measurement for the humidity in the environment is recorded and evaluated, and in that, if it can be concluded from the evaluation according to step b) that there is an existing or imminent blockage of the flow path (2), the cause of the existing or imminent blockage is determined using the measurement for the ambient temperature and/or for the humidity in the environment.
2. Method according to claim 1, characterised in that the recording according to step a) is performed by means of at least one sensor (4) of the heater (2).
3. Method according to claim 1 or 2, characterised in that the recording according to step a) is performed under a specific operating condition of a conveyor apparatus (6) of the heater (1).
4. Method according to any one of the preceding claims, wherein icing or bird nesting is ascertained as the cause of the blockage.
5. Method according to any one of the preceding claims, wherein the determination of the cause comprises ascertaining whether the existing or imminent blockage is due to icing of the flow path or ice formation in the flow path.
6. Method according to any one of the preceding claims, wherein, if ambient temperatures above a predefinable temperature limit value and/or humidity levels in the environment below a predefinable humidity limit value indicate an existing or imminent blockage of the flow path (2), it is determined therefrom that a blockage of the flow path (2) is present or imminent which is not due to icing or ice formation, but is attributable to bird nesting.
7. Method according to any one of the preceding claims, wherein it is concluded that a blockage is imminent if it is apparent from recording processes spaced apart in time according to step a) that the recorded measurement for the flow through the flow path (2) changes in the same direction from recording process to recording process.
8. Method according to any one of the preceding claims, wherein at least part of the reference data for the evaluation according to step b) is ascertained during operation of the heater (1) with an inactive burner.
9. Heater (1) for a building (3), wherein a flow path (2) fluidically connects the heater to the environment outside the building (3), wherein the heater comprises a control device (7), means (4) for recording at least one measurement for the flow through the flow path (2), as well as means for recording a measurement for the ambient temperature and/or means for recording a measurement for the humidity in the environment, wherein the control device (7) is configured to perform a method according to any one of claims 1 to 8.
10. Computer program comprising instructions which, when executed by a control device (7) of a heater (1) according to claim 9, perform a method according to any one of claims 1 to 8.
11. Machine-readable storage medium on which the computer program according to claim 10 is stored.
12. System comprising a heater (1) according to claim 9 as well as at least a part of an exhaust system connectable to the heater (1) and/or at least a part of a supply air system connectable to the heater (1).

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