METHOD FOR TESTING A CHECK VALVE IN A HEATING SYSTEM

Description

[0001] The invention relates to a method for testing a non-return valve in a heating system, a computer program, a storage medium, a control and regulating device, a heating device and an application.

[0002] For example, in apartment buildings, several gas heating appliances are often connected to a shared exhaust system. Such systems are called multi-occupancy systems. To prevent exhaust gas backflow, check valves are usually used, which prevent exhaust gases from one heating appliance from flowing back into other heating appliances in the multi-occupancy system.

[0003] When commissioning heating appliances, the presence of a non-return valve usually needs to be indicated by making a setting in the appliance's control unit. However, a heating appliance would also operate if the setting has been made in the control unit, but the non-return valve has not been installed or is defective. Conversely, a non-return valve would also operate if it is installed, but the setting has not been made in the control unit.

[0004] EP 3 712 502 A1 proposes a method for checking the presence of a check valve, in which an operating parameter of a conveying device of the heating appliance is changed in such a way that the fluid flow conveyed by the heating appliance and exhaust system is altered. By simultaneously measuring the fluid flow using a suitable parameter, it can be determined whether a check valve is present.

[0005] However, it has been shown that the mass flow sensor required to carry out the procedure is associated with costs and increases the complexity of a heating device, which is accompanied by an increased probability of failure.

[0006] Based on this, the object of the present invention is to at least partially overcome the problems described with reference to the prior art. In particular, a solution is to be proposed that does not increase the complexity of a heating device compared to the prior art.

[0007] These problems are solved by the features of the independent claims. Further advantageous embodiments of the solution proposed here are specified in the dependent claims. It should be noted that the features listed in the dependent claims can be combined with one another in any technologically meaningful way and define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, which also presents further preferred embodiments of the invention.

[0008] This includes a procedure for testing a non-return valve in a heating system with at least one heating device, which comprises at least the following steps: a) Changing an operating parameter of the heating device that can cause a change in the fluid flow conveyed by a conveying device of the heating device, b) Detecting a comparison parameter that allows a conclusion to be drawn about the power consumption of the conveying device of the heating device, c) Detecting the presence of a check valve if the comparison parameter is at least temporarily independent of the change in the operating parameter.

[0009] The comparison parameter is a control signal for the conveying device. Using this control signal, a conveying device can, for example, be regulated to a defined speed by a controller, particularly a pi controller. The control signal can be, in particular, a pulse-modulated signal, such as a pulse-duration modulated, a pulse-length modulated, or a pulse-width modulated signal; preferably, the control signal can be a pulse-width modulated signal (PWM signal).

[0010] Steps a), b), and c) are typically performed at least once in the specified sequence during regular operation. It is also possible for steps a) through c) to be repeated multiple times (in the specified sequence). In particular, it is conceivable that steps a) and b) are repeated several times consecutively before step c) is performed. Furthermore, steps a), b), and c), or at least steps a) and b), can also be performed at least partially in parallel or even simultaneously. The procedure can also be carried out using a heating device, which is also described herein.

[0011] The method can be used in particular for the automatic detection of the existence and / or functionality of the backflow preventer. The method can (also) be used to detect a misadjustment of the heating device.

[0012] The solution presented here describes a particularly advantageous and / or reliable method for (automatically) detecting whether a check valve is installed in a heating system with multiple occupancy units. In other words, the method can also be described as an automatic backflow valve detection system. In this context, the method can be used to (automatically) check for the presence of a check valve in a heating system with at least one heating appliance. Furthermore, according to one embodiment of the method, a heating appliance malfunction can be detected.

[0013] In principle, this method can be used when integrating a (new or additional) heating appliance into a (multi-occupancy) heating system and / or during the commissioning of such a heating appliance. This advantageously allows faulty installations or settings of the heating appliance in the heating system, in particular a missing or defective check valve, to be detected as early as possible and the consequences described above to be avoided.

[0014] Alternatively or cumulatively, the procedure can also be carried out as needed, at specific times, or after certain operating intervals during the operation of the heating appliance. This can, for example, help to detect whether a check valve (in the open position) has jammed. Thus, the procedure can also be used generally to test the function of an (existing) check valve. The detection of the check valve's absence during operation (i.e., after it has been detected once during commissioning) can be interpreted as a malfunction of the valve.

[0015] A check valve can also be generally referred to as a non-return valve. A check valve typically opens in only one direction. Its primary function is to prevent the (unwanted) backflow of exhaust gas from a heating appliance in one apartment of a building into another apartment in the same building. The check valve can be located, for example, in a mixture duct, an air intake duct, and / or in the exhaust pipe of the heating appliance, and / or at the connection point between the heating appliance and the heating system, or between the heating appliance and a shared exhaust system of the heating system. The check valve can be designed to open when a predetermined fluid flow (air or mixture flow) through the heating appliance is reached (or when a predetermined fluid flow threshold is exceeded), and to close under a minimum flow rate (or when the threshold is not reached) due to the check valve's own weight.The check valve can also be spring-loaded, either alternatively or cumulatively. A "flap" in this sense does not necessarily have to be a pivoting closure element; rather, it can also include other movable closure elements, such as ball valves, axially movable slides, etc.

[0016] The heating system in question is a so-called multi-occupancy system. This is characterized by the fact that several heating appliances (from different apartments) are connected to a common exhaust system (of a building), which may vent to the surrounding area via a chimney.

[0017] The heating appliance in question is typically a gas and / or oil-fired boiler. In other words, this refers specifically to a heating appliance designed to burn one or more fossil fuels, such as natural gas and / or heating oil, possibly with the addition of ambient air from a dwelling, to generate energy for heating, for example, water for use within the dwelling. The heating appliance might, for instance, be a so-called condensing gas boiler. The heating appliance generally has at least one burner and a delivery system that supplies a mixture of fuel (gas) and combustion air (through a mixing channel within the boiler) to the burner. The exhaust gas produced by combustion can then be routed through an (internal) flue pipe of the heating appliance to a building's exhaust system. Several heating appliances are typically connected to this exhaust system.

[0018] According to a preferred embodiment of the process, preferably no fuel is supplied during the execution of the process. Preferably, the heating device can only be released for commissioning after successful completion of the process.

[0019] In step a), an operating parameter of the heating device is changed (in a targeted and / or controlled manner), which can cause a change in the fluid flow through the heating device. The operating parameter can be, for example, a rotational speed and / or [missing information]. The conveying device can be, for example, a blower, a propeller, a compressor, or the like. Preferably, the conveying device is a blower. In other words, the fluid flow through the heating device describes a fluid flow passing through (at least partially) the heating device, in particular a channel of the heating device. The fluid flow can be characterized by a volumetric flow rate and / or a mass flow rate. The fluid can be, for example, (combustion) air, fuel (in particular gas), exhaust gas, and / or a mixture of air and fuel.

[0020] Changing an operating parameter can be achieved, for example, by increasing or decreasing it from a predefined (constant) starting value to a predefined (constant) final value. This increase or decrease can be continuous and / or linear. However, a sudden or abrupt change in the operating parameter is also conceivable. Furthermore, several different operating parameters can be changed (at least partially in parallel or even simultaneously).

[0021] Alternatively or cumulatively, the operating parameter can also be changed so that a predefined threshold value of the operating parameter and / or the fluid flow is exceeded or fallen below. Here too, increasing or decreasing the operating parameter can generally be done continuously and / or linearly. The threshold value is specifically set such that if the threshold value is exceeded, an existing check valve would just open, and / or if the threshold value is not reached, an existing check valve would just close.

[0022] In an advantageous embodiment, it is proposed that the operating parameter be the rotational speed of a conveying device of the heating unit. This advantageously allows for the simplest and most precise implementation of the method. In particular, this is the rotational speed of a blower of the heating unit. The rotational speed can advantageously be detected by a speed sensor of the conveying device and is advantageously already available to a control unit of the heating unit.

[0023] In step b), a comparison parameter is recorded that allows conclusions to be drawn about the power consumption of the heating device's conveying system. The comparison parameter can, in particular, be an electrical signal that allows a (direct) inference about the power consumption of the heating device's conveying system.

[0024] In step c), the presence of a check valve is detected if the comparison parameter behaves independently of the operating parameter change, at least temporarily (during or immediately after the change). For example, if the operating parameter is the speed of the conveying device, a brief reduction or stagnation of the speed and / or a brief increase in the electrical signal, allowing for a (direct) inference about the power consumption of the conveying device or the heating unit, can be detected at the moment a check valve opens due to the pressure built up by the conveying device. In other words, a brief disturbance, i.e., a brief increase or decrease in the parameter, can be detected in the parameter profiles of the operating and comparison parameters when a check valve opens or closes.The parameter profiles during this short-term disturbance show, in particular, an inverse profile (one parameter decreases while the other increases), for example, with a PWM signal as a comparison parameter and a speed of the conveying device as an operating parameter).

[0025] According to a further preferred embodiment of the method, it is additionally recorded whether a multiple occupancy mode has been activated in the heating device's settings. Activation of the multiple occupancy mode can refer to any setting of the heating device that signals a multiple occupancy mode, i.e., the presence of a check valve, to the heating device.

[0026] By recording the "Multiple Occupancy Mode" setting, the proposed procedure can be used to check whether a check valve has been detected despite the fact that a multiple occupancy mode is not activated in the heating appliance's settings. Advantageously, the heating appliance can perform this procedure before each commissioning or new commissioning and compare the result with the multiple occupancy mode settings configured in the appliance. This also allows for the detection of missing settings in the heating appliance or highlights a discrepancy between the heating system's configuration (check valve present) and the corresponding settings in the heating appliance (multiple occupancy mode not activated).

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

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

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

[0030] Another aspect is the proposal for a control unit for a heating appliance, designed to carry out the procedure presented here. This control unit can, for example, include or be equipped with a processor. In this context, the processor can, for instance, execute the procedure stored in the control unit's memory.

[0031] Another aspect is the proposed heating system with a control unit as presented here. This control unit is often a component of the heating system's boiler. The boiler is typically a gas boiler with a gas burner and a delivery system that supplies a mixture of gas and combustion air (combustible mixture) to the gas burner.

[0032] Another aspect proposes using a control signal and an operating parameter of a conveying device in a heating appliance to check for the presence of a non-return valve in a heating system. The operating parameter is preferably the speed of the conveying device and / or the control signal is preferably a digital control signal, in particular a pulse-modulated or PWM signal.

[0033] This document presents a method for testing a non-return valve in a heating system, a computer program, a control unit, and a heating device for carrying out the method, as well as an application, which at least partially solve the problems described with reference to the prior art. In particular, the method, the computer program, the control unit, the heating device, and the application each contribute to enabling simple and reliable detection of the presence of a non-return valve in a heating system. Furthermore, the complexity of the heating device is advantageously not increased, as the proposed method can be implemented without additional sensors.

[0034] The invention and its technical context are explained in more detail below with reference to the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the situations described in the figures and combine them with other components and findings from the present description. It should be emphasized that the figures, and especially the depicted dimensions, are only schematic. They show: Fig. 1: a sequence of a method proposed here, Fig. 2: a heating device proposed here, and Fig. 3: an illustration of parameter curves that may result when carrying out a method presented here.

[0035] Figure 1Figure 1 shows an exemplary and schematic representation of the sequence of a procedure proposed here. The procedure serves to check (the presence of) a non-return valve 1 in a heating system with at least one heating appliance 2. The sequence of steps a), b), and c), depicted by blocks 110, 120, and 130, can occur during normal operation.

[0036] Fig. 2 Figure 1 shows an exemplary and schematic representation of a heating device 2 proposed here. The heating device 2 has a control unit 8 which is set up to carry out a procedure presented here.

[0037] The heating appliance 2 (e.g., a gas condensing boiler) is equipped with a burner system in which, upstream of a blower (here represented by an example of a conveying device 5), the gas from a gas valve 3 and a gas supply channel 13 and the combustion air from an air intake channel 12 are combined in a mixing point 14 and a mixture channel 11. This mixture is then transported by the conveying device 5 via the mixture channel 11 to a burner 9, where combustion takes place. The exhaust gases produced by combustion are routed through an internal exhaust pipe 10 to an exhaust system (not shown here). The conveying device 5 is connected to the control unit 8 via a signal line 7, through which a control signal can be transmitted. The conveying device 5 may have a speed sensor 6 that detects the speed of the conveying device 5 and transmits it to the control unit 8.

[0038] A check valve 1 is arranged in the mixture channel 11. This valve opens at a predetermined air or mixture flow rate (i.e., a predetermined threshold value) and closes below a minimum flow rate due to the check valve 1's own weight. Alternatively, such a check valve 1 could also be arranged in the air intake channel 12 or the exhaust pipe 10. The check valve 1 could also be spring-loaded, either alternatively or in combination.

[0039] In block 110, according to step a), an operating parameter 3 of the heating device 2 is changed, which can cause a change in the fluid flow through the heating device 2. In block 120, according to step b), a comparison parameter 4 is recorded, which allows conclusions to be drawn about the power consumption of the conveying device 5 of the heating device 2. In block 130, according to step c), the presence of the check valve 1 is detected if the comparison parameter 4 is at least temporarily independent of the change in operating parameter 3.

[0040] Fig. 3Figure 1 shows an exemplary and schematic illustration of parameter profiles over time that can result from the execution of a procedure presented here. Operating parameter 21 is, for example, the rotational speed of the conveying device 5 of the heating unit 2, and comparison parameter 20 is a control signal of the conveying device 5, specifically a PWM signal. The PWM signal can be specified as a percentage of the time fraction of a period during which the PWM signal is active. The rotational speed, as operating parameter 21, can be specified in revolutions per minute.

[0041] When carrying out the proposed procedure, for example, the conveying device 5 can be driven to a speed 26. The speed can increase almost linearly from the idle state, and the PWM signal, as a comparison parameter 20, can remain largely constant or decrease slightly. At a certain point 27, the check valve 1 can open due to the pressure built up by the conveying device 5. The opening of the check valve 1 can trigger a fault 25, in which the increase in the speed of the conveying device 5, as an operating parameter 21, or even the speed itself, can decrease for a short period (compared to an initial parameter profile 24).Simultaneously, the PWM signal, used as a comparison parameter 20, can experience a disturbance 23 and increase abruptly compared to an original curve 24, for example, because a controller increases the power consumption of the conveying device 5 to counteract a drop in the speed of the conveying device 5 associated with the opening of the check valve 1. The evaluation electronics of the process control unit 8 can now detect the presence of a check valve 1. If a check valve 1 is absent, the control unit 8 can put the heating device 2 into a fault mode, in which commissioning is blocked and which can only be terminated by technical personnel.

[0042] According to an optional configuration, the control unit 8 can detect whether a multiple occupancy mode has been activated in the settings of the heating unit 2. If the multiple occupancy mode is not activated, but a non-return valve 1 has been detected, the control unit 8 can put the heating unit 2 into a fault mode, in which commissioning is blocked and which can only be ended by technical personnel. Reference symbol list

[0043] 1 Check valve 2 Heater 3 Gas valve 5 Conveyor 6 Speed ​​sensor 7 Signal line 8 Control unit 9 Burner 10 Exhaust pipe 11 Mixing channel 12 Air intake channel 13 Gas supply channel 14 Mixing point 20 Comparison parameter 21 Operating parameter 23 Original profile 24 Original profile 26 Speed ​​27 Check valve opening time

Claims

1. Method for testing a non-return valve (1) in a heating system with at least one heating device (2), comprising at least the following steps: a) Changing an operating parameter (3) of the heating device (2) which can cause a change in a fluid flow conveyed by a conveyor device (5) of the heating device (2) through the heating device (2), b) Detecting a comparison parameter (4) that allows conclusions to be drawn about the power consumption of the conveyor device (5) of the heating device (2), wherein the comparison parameter is a control signal of the conveyor device (5) of the heating device (2), c) detecting the presence of a non-return valve (1) when the comparison parameter (4) runs at least temporarily independently of the change in the operating parameter (3).

2. Method according to claim 1, wherein the operating parameter (3) is a rotational speed of a conveyor device (5) of the heating device (2).

3. Method according to one of the preceding claims, wherein the control signal is a PWM signal.

4. Method according to one of the preceding claims, wherein the method is carried out before each start-up of the heating device (2) and it is additionally detected whether a multiple occupancy mode of the heating device (2) has been activated.

5. Method according to one of the preceding claims, wherein if the presence of a non-return valve (5) is not detected and / or if the presence of a non-return valve (5) is detected and the multiple occupancy mode is not activated, commissioning of the heating device (2) is blocked in step d).

6. Control unit (8) for a heating device (2), wherein the control unit (8) is designed to cause the heating device (2) to perform the method steps according to one of claims 1 to 5.

7. Heating device (2) with a control device (8) according to claim 6.

8. Computer program comprising commands which, when executed by a control device (8) according to claim 6 of a heating device (2) according to claim 7, cause the heating device (2) to carry out the method steps according to one of claims 1 to 5.

9. Machine-readable storage medium on which the computer programme according to claim 8 is stored.

10. Use of a control signal and an operating parameter of a conveyor device (5) of a heating device (2) for testing a non-return valve (1) of a heating system.