METHOD FOR OPERATING A HEATING APPLIANCE, COMPUTER PROGRAM, STORAGE MEDIUM, CONTROL AND REGULATION DEVICE, HEATING APPLIANCE AND USE OF A TEMPERATURE SENSOR

Description

[0001] The invention relates to a method for operating a heating device, a computer program, a storage medium, a control and regulating device, a heating device and a use of a temperature sensor.

[0002] Condensate typically occurs during combustion in heating devices, for example, during the combustion of fuel gases such as natural gas or hydrogen. The condensate is often drained from the combustion chamber and the heating device through a drain, which may often include a siphon.

[0003] Obviously, a blocked drain or siphon can cause problems. Condensate can no longer drain away and collects in the combustion chamber, where it can potentially flow into the burner and / or further into the gas supply. This can cause significant damage to the heater.

[0004] In devices with ionization current-based flame detection, the ionization electrode can be located below the burner. If the (condensate) drain is blocked, the condensate could only collect up to the initiation electrode because contact between the ionization electrode and the condensate would interrupt the ionization current, and the heater would shut down due to a lack of flame detection. Such a system is described, for example, in DE 10 2015 206 810 A1. However, this solution cannot be used in heaters with an incorrectly positioned ionization electrode and / or in heaters with an alternative flame detection system.

[0005] To prevent a heater drain from becoming blocked, GB 2187 829 A proposes collecting condensate generated in the heater in a container and then emptying the entire container via the drain. This is intended to reduce the risk of a drain blockage.

[0006] GB 249 7140 A proposes providing a connector in a condensate drain pipe with a switch that can be activated by the condensate flowing out of the drain pipe. The switch can, via communication, trigger another switch to shut off the heater.

[0007] US 5,024,595 A discloses a system in which a flame monitoring circuit is closed when a certain condensate level is reached in a manifold, thus shutting off the gas supply to the heating unit. However, this method is only applicable to heaters with appropriate flame monitoring.

[0008] DE 4 134 230 A1 describes a heating device in which a device is provided in a condensate drain to maintain a certain minimum head. This device can be a valve seat and a valve body. However, this heating device cannot help detect a blocked condensate drain.

[0009] US 2018 / 216849 A1 describes a device for neutralizing condensate, comprising a chamber containing materials for neutralizing condensate and having an inlet and an outlet. Even this complex device cannot help solve the current problem of detecting a blocked condensate drain.

[0010] EP 3 171 094 A1 describes a condensing boiler in which a pump is provided in a condensate drain to drain accumulated condensate. This boiler also fails to solve the problem of simply detecting a blocked condensate drain.

[0011] The main disadvantage of these systems is their complexity, which not only increases the probability of failure but also increases the costs of manufacturing and assembly.

[0012] Based on this, the object of the invention is to propose a method for operating a heater that at least partially overcomes the described problems of the prior art. In particular, the method is intended to provide a very simple and reliable way to detect a blockage in a (condensate) drain and prevent subsequent damage.

[0013] In addition, the invention should at least not significantly increase the complexity of a heater, require only minor structural changes to a heater and enable easy integration into an existing production process.

[0014] These objects are achieved by the features of the independent patent claims. Further advantageous embodiments of the solution proposed here are specified in the independent patent claims. It is pointed out that the features listed in the dependent patent claims can be combined with one another in any technologically expedient manner and define further embodiments of the invention. Furthermore, the features specified in the patent claims are further specified and explained in the description, with further preferred embodiments of the invention being presented.

[0015] A method for operating a heating device contributes to this, comprising the following steps: a) detecting a temperature in an area below the burner of the heater, b) comparing the temperature detected in step a) with a limit temperature, c) detecting a blocked outlet of the combustion chamber if, in the comparison according to step b), the temperature detected in step a) is below the limit temperature.

[0016] In a regular process sequence, steps a), b), and c) are generally performed at least once in the specified order. In particular, it is possible to repeat steps a) to c) several times in the specified order. It is also conceivable to perform steps a) to c) continuously or at regular intervals (every second or minute).

[0017] The invention can be used, in particular, to detect a blocked drain of a heater. A blockage of the drain would result in condensate from the heater's combustion chamber no longer being able to drain away and would collect in the combustion chamber, which could cause significant damage to the heater. The invention is based, in particular, on the idea that liquid condensate within a combustion chamber has a maximum temperature (usually approximately 100 °C), which is significantly lower than the temperature of an operating combustion chamber.

[0018] In principle, the method proposed here can be used in any heating device that generates significant amounts of condensate during operation. The present invention appears particularly useful in heating devices that do not have ionization current-based flame detection. However, the method proposed here can also be easily implemented in heating devices with ionization current-based flame detection.

[0019] The heater is, in particular, a gas heater designed to combust a gaseous fuel, such as natural gas or, in particular, hydrogen, with the addition of ambient air, in order to provide heat, for example, for a heating circuit and / or a hot water supply. The heater typically has at least one burner and a conveying device (such as a fan) that conveys a mixture of fuel (gas) and combustion air through a mixture duct of the heater to the burner; the exhaust gas produced by the combustion can then be guided through an exhaust pipe of the heater to an exhaust system. Furthermore, the heater has an outlet for condensate produced during combustion. The outlet may comprise a siphon. The condensate can be conveyed to a suitable location, such as a sewer, via the outlet and / or the siphon.

[0020] The drain is usually located at the lowest point of the combustion chamber to ensure the most complete drainage of the condensate. The drain often includes a siphon, a U-shaped area that seals the drain gas-tight, preventing external air from entering the combustion chamber. A blockage of the drain is often caused by or within the siphon. A blockage of the drain can result in its complete closure or in such a reduced drainage speed that the condensate cannot drain away sufficiently and collects in the combustion chamber. A "blockage" here, therefore, specifically means that the condensate cannot drain away or can only drain away insufficiently.

[0021] According to step a), a temperature is detected in an area below the burner of the heater. In particular, a signal from a temperature sensor located in the area below the burner can be detected. By arranging the sensor in an area below the burner, it can be ensured that any condensate that is not draining away is detected before it reaches the burner above and, if applicable, the gas supply.

[0022] In principle, any temperature sensor can be used to measure the temperature according to step a). In particular, a resistance-based temperature sensor, such as an electrical thermistor or PTC thermistor, a platinum or silicon measuring resistor, or even a semiconductor temperature sensor can be used.

[0023] According to a preferred embodiment, the temperature sensor can be an ignition device, in particular a hot-surface igniter of the heater, which should be arranged below the burner for carrying out a method proposed here. A hot-surface igniter has a temperature-dependent resistance and is therefore suitable as a temperature sensor. Advantageously, this does not increase the complexity of a heater, and no additional components are required to carry out a method proposed here.

[0024] According to an advantageous embodiment, in step a), a temperature can also be measured outside the combustion chamber in a position below the burner. Advantageously, a temperature sensor located there is easily accessible and, due to its proximity to the burner door cable harness, also easy to connect. Last but not least, the temperature sensor located in this position is not exposed to the corrosion- and wear-promoting conditions within the combustion chamber. When defining the limit temperature or evaluating a signal from a temperature sensor located outside the burner door, the thermal conduction and thermal properties of the burner door or burner wall must be taken into account. Last but not least, a signal delay due to the increased thermal mass of the sensor caused by the inclusion of the burner door or burner wall should also be taken into account.

[0025] According to step b), the temperature measured in step a) is compared with a predetermined limit temperature. For a temperature sensor located inside the combustion chamber, the limit temperature can be in a range of approximately 100 °C. For a temperature sensor located outside the combustion chamber, the limit temperature can be below the aforementioned 100 °C to compensate for heat conduction and the heat capacity of the burner door or burner wall.

[0026] According to step c), a blocked heater drain is detected if, in the comparison according to step b), the temperature detected in step a) is below the threshold temperature. The threshold temperature is selected in particular so that the presence of water at or in the immediate vicinity of the temperature sensor can be detected. Therefore, the threshold value is significantly below typical combustion chamber temperatures.

[0027] According to an advantageous embodiment, in step d), after detecting a blocked heater process according to step c), the heater can be shut down. This can, in particular, result in the automatic stopping of combustion in the heater.

[0028] According to a further advantageous embodiment, upon detection of a blocked process according to step c), the heater can provide or send information about the blocked process in a step e). Advantageously, the heater can thus automatically inform an operator, user, or specialist company about the blocked process and, if necessary, a shutdown of the heater. In particular, the information can be provided or sent via a network, in particular the Internet. For example, after detecting a blocked process 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 process.

[0029] The process is particularly suitable for operating the heater with hydrogen.

[0030] According to a further aspect, a computer program is also proposed which is configured to (at least partially) carry out a method presented here. In other words, this relates in particular to a computer program (product) comprising instructions which, when executed by a computer, cause the computer to execute a method described here.

[0031] 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.

[0032] According to a further aspect, a control device for a heater is also proposed, configured to carry out a method presented here. The control device can, for example, have or be equipped with a processor for this purpose. In this context, the processor can, for example, execute the method stored in a memory (of the control device). Furthermore, one or more limit temperatures for carrying out a method presented here can also be stored in a memory of the control device.

[0033] According to a further aspect, a heating device with a control and regulation device as presented here is also proposed. The heating device is, in particular, a gas heating device with a gas burner and a conveying device that can convey a mixture of gas (in particular hydrogen) and combustion air to the gas burner.

[0034] According to one embodiment, the heater may have a temperature sensor arranged in a region below the burner of the heater.

[0035] According to an advantageous embodiment of the heater, the temperature sensor can be arranged on the outside of the combustion chamber, in particular on the burner door or a burner wall, of the heater.

[0036] According to a further advantageous embodiment of the heating device, it can be designed to switch itself off if a temperature detected by the temperature sensor is below a limit temperature.

[0037] According to a further advantageous embodiment of the heater, the temperature sensor can be a temperature sensor for thermal flame detection of the heater. Thus, an existing temperature sensor can advantageously be used to implement the method proposed here.

[0038] According to a further aspect, the use of a temperature sensor is proposed, wherein the temperature sensor is arranged below a burner inside or outside a combustion chamber of a heater, for detecting a blocked (condensate) drain (of the combustion chamber) of the heater. The blocked condensate drain is detected by detecting a temperature at the temperature sensor below a threshold temperature.

[0039] The details, features, and advantageous embodiments discussed in connection with the method may also occur correspondingly in the computer program, storage medium, control device, heater, and / or use presented here, and vice versa. In this respect, reference is made in full to the explanations therein for a more detailed characterization of the features.

[0040] Thus, a method for operating a heater, a computer program, a storage medium, a control device, a heater, and the use of a temperature sensor are provided, which at least partially solve the problems described with reference to the prior art. In particular, the method and the heater contribute to providing a simple and reliable method for detecting a blocked condensate drain of a heater.

[0041] Furthermore, the invention is easy to implement and cost-effective, and it increases the complexity of a heating device only minimally or not at all. The invention can also be easily implemented on existing devices.

[0042] The invention and the technical environment are explained in more detail below with reference to the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments cited. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other components and findings from the present description. In particular, it should be noted that the figures, and in particular the proportions shown, are only schematic. They show: Fig. 1 : a sequence of a procedure proposed here, Fig. 2 : a heater proposed here, and Fig. 3 : a combustion chamber of a heating device proposed here.

[0043] Fig. 1 shows, by way of example and schematically, a sequence of a method proposed here. The method serves to detect a blocked (condensate) drain 14 of a heater 1. The sequence of steps a), b), and c) illustrated by blocks 110, 120, and 130 can occur during normal operation. In particular, however, simultaneous (permanent) or regularly staggered execution of steps a) to c) may be appropriate.

[0044] In block 110, according to step a), a temperature is detected in an area below the burner 3 of the heater 1. In block 120, according to step b), the temperature detected in step a) is compared with a limit temperature. In block 130, according to step c), a blocked outlet 14 of the combustion chamber 8 is detected.

[0045] Fig. 2 shows, by way of example and schematically, a heating device 1 proposed here. The heating device 1 can have a combustion air supply 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. Resulting combustion products can be discharged from the combustion chamber 8 via an exhaust system 9.

[0046] The heater 1 can also have a control unit 7, which can be electrically connected to a temperature sensor 10 located in the combustion chamber 8 below the burner 3. Furthermore, the control unit 7 can be electrically connected to the gas valve 5, the delivery device 2, and an ignition device 6. A method proposed here can advantageously be implemented on the control unit 7.

[0047] Fig. 3 shows, by way of example and schematically, a combustion chamber 8 of a heating device 1 proposed here. Combustion mixture can be fed to the burner 3 via the mixture channel 16 and burned to form a flame 11. The flame 11 can be monitored by a UV sensor 12. The combustion chamber 8 can also have an ionization electrode 13, which is also suitable for monitoring the flame 11. The temperature sensor 10 can be arranged below the ionization electrode 13. The UV sensor 12, burner 3, ionization electrode 13, and temperature sensor 10 can be arranged in a burner door 17, which advantageously simplifies electrical wiring.

[0048] At the bottom, the combustion chamber 8 can have a (condensate) drain 14, which can include a siphon 15. If the drain 14 is blocked, the condensate in the combustion chamber can rise to the level of the temperature sensor 10 and then cool it to condensate temperature, thus below the limit temperature. According to the method proposed here, the heater 1 would then shut down, preventing a further rise in the condensate level in the combustion chamber 3. Damage to the heater 1, in particular to the burner 3, can thus be effectively prevented. List of reference symbols

[0049] 1Heater 2Feeding device 3Burner 4Combustion air supply 5Gas valve 6Ignition device 7Regulating and control unit 8Combustion chamber 9Exhaust system 10Temperature sensor 11Flame 12UV sensor 13Ionization electrode 14Drain 15Siphon 16Mixing channel 17Burner door

Claims

1. Method for operating a heating appliance (1), comprising at least the following steps: a) detecting a temperature in an area below the burner (3) of the heating appliance (1), b) comparing the temperature detected in step a) with a limit temperature, c) identifying a blocked outlet (14) of the combustion chamber (8), if, in the comparison according to step b), the temperature detected in a step a) is below the limit temperature.

2. Method according to claim 1, wherein in a step d) after detecting a blocked outlet (14) according to step c) the heating appliance is switched off.

3. Method according to any one of the preceding claims, wherein in a step e) after detecting a blocked outlet (14) according to step c), the heating appliance (1) provides or transmits information about the blocked outlet (14).

4. Method according to any one of the preceding claims, wherein in step a) a temperature is detected outside of a burner door (17) in an area below the burner (3).

5. Method according to any one of the preceding claims, wherein the heating appliance (1) is operated with hydrogen.

6. Computer program, which, when executed by a regulating and control appliance (7) of a heating appliance (1), causes the heating appliance (1) to perform a method according to any one of the preceding claims.

7. Machine-readable storage medium, on which the computer program according to claim 6 is stored.

8. Regulating and control appliance (7) for a heating appliance (1), configured to cause the heating appliance (1) to perform a method according to any one of claims 1 to 5.

9. Heating appliance (1), having a regulating and control appliance (7) according to claim 8.

10. Heating appliance (1) according to claim 9, having a temperature sensor (10), arranged below the burner (3) of the heating appliance (1).

11. Heating appliance according to claim 10, wherein the temperature sensor (10) is arranged on the outside of the burner door.

12. Heating appliance (1) according to any one of claims 10 or 11, wherein the heating appliance (1) is configured to switch itself off if the temperature detected at the temperature sensor (10) is below a limit temperature.

13. Use of a temperature sensor (10), which is arranged below a burner (3) in a heating appliance (1), for detecting a blocked outlet (14) of the heating appliance (1), if the temperature detected at the temperature sensor (10) is below a limit temperature.