ES2983868T3 - Procedure for checking the presence of a non-return valve in a heating installation - Google Patents

Abstract

The invention relates to a method for testing a check valve (1) in a heating system with at least one heater (2), comprising at least the following steps: a) changing an operating parameter (3) of the heater (2) that can cause a change in a fluid flow through the heater (2), b) detecting a measurement parameter (4) that allows a conclusion to be drawn about the fluid flow through the heater (2), c) detecting the presence of a check valve (1) if the measurement parameter (4) is at least temporarily independent of the change in the operating parameter (3). (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Procedure for checking the presence of a non-return valve in a heating installation

Description

The invention relates to a method for testing a non-return valve in a heating installation with at least one heating device, a computer program, a machine-readable storage medium, a control unit, a heating device and a use of a heating device.

EP 1503 151 A1 provides an air conditioning and heating system which has a supply line with an inlet into a room of a building and consists of a ventilation unit, a connecting piece and a heating unit. The ventilation unit contains a control unit and is arranged between the inlet and a supply duct. The connecting piece is located in the supply duct. The piece also has a first non-return valve between the branches for the supply openings and the supply opening. The heating unit has, in series with one another, a further non-return valve, a fan and a combustion unit. In particular, it is proposed to check the function of the valve, which is assumed to be present, at intervals.

JP 2017 138012 A discloses a combustion chamber with downward combustion, which is capable of reducing ignition failures when the returning steam is frozen. A non-return valve is provided for this purpose in order to allow trouble-free combustion and ensure high safety.

EP 3396248 A1 relates to a diagnostic option for detecting faults in a gas safety valve in heating appliances. The proposed method comprises the following steps: (i) measuring, by means of a sensor, the mass or volume flow of the combustion air supplied; (ii) constructing the gradient of the sensor measurement signal; (iii) assigning the course of the gradient to stored fault images; (iv) detecting the fault based on the assigned gradient; and (v) emitting a fault signal.

In heating systems with several gas-fired heating appliances in a common flue gas system (so-called multiple-use system), non-return valves are installed to prevent the return flow of flue gases. In addition, a multiple-use mode is usually activated in the heating appliance control unit, which adapts the heating appliance's control parameters.

When such heating devices are put into operation, the device is usually set manually or electronically. However, the devices are also normally operated even if the non-return valve is incorrectly fitted or (accidentally) not fitted and/or the multiple-use mode setting has not been made. This requires appropriate training and understanding on the part of those who put the device into operation. This fault case (non-return valve failure) can lead to exhaust gases entering the heating device under pressure or, in the worst case, even exhaust gases reaching the building where the device is located.

In view of this, it is an object of the present invention to at least partially solve the problems outlined with reference to the prior art. In particular, a method for checking a non-return valve in a heating system with at least one heating device, a control unit and a heating device for carrying out the method, and a use of a heating device are to be provided, which in each case contribute at least to increasing the operational safety of a multiple-use system. In addition, the integration of a heating device into a multiple-use system is to be simplified and made more reliable.

These tasks are solved by the features of the independent patent claims. Further advantageous embodiments of the solution proposed here are indicated in the dependent claims. It should be noted that the features set out individually in the dependent patent claims can be combined with each other in any technologically sensible manner and define further embodiments of the invention. Furthermore, the features indicated in the patent claims are specified and explained in more detail in the description, and further preferred embodiments of the invention are presented.

This is supported by a method for checking the presence of a non-return valve in a heating installation with at least one heating device, where the non-return valve is configured to prevent backflows of flue gases, which comprises at least the following steps that are carried out when a heating device is integrated into the heating installation and/or during the commissioning of such a heating device:

a) modify an operating parameter of the heating device, which may cause a modification of a fluid flow through the heating device,

b) detect a measurement parameter that allows an inference about the fluid flow through the heating apparatus,

c) recognize the presence of a non-return gate if the measurement parameter evolves, at least for a time, without showing a relationship with the modification of the operating parameter,

d) cause the heating device to switch to an incident state and/or to a deactivated state if no non-return valve has been recognized.

The solution described here describes a particularly advantageous and safe option for (automatically) detecting whether a non-return valve is installed in a heating system in a multiple-use system. The method can also be described in other words as automatic non-return valve detection. In this context, the method serves to (automatically) check the presence of a non-return valve in a heating system with at least one heating device.

The method is used when a (new or additional) heating device is integrated into a (multi-purpose) heating system and/or when such a heating device is put into operation. This advantageously makes it possible to detect faulty installations of the heating device in the heating system as early as possible and to avoid the consequences described above.

In addition, the procedure can also be carried out as required, at certain times or after certain operating time intervals during operation of the heating appliance. This can help, for example, to recognise whether a non-return flap is stuck (in the open position). The procedure can therefore generally also be used to check the function of an (existing) non-return flap. Recognition of the absence of the non-return flap during operation (i.e. after it has been detected once during commissioning) can be interpreted as a malfunction of the flap.

In general, the non-return valve can also be referred to as a check valve. The non-return valve usually only opens in one direction. It is used to prevent (unintentional) backflow of flue gases from a heating appliance from one dwelling in a building into another dwelling in the building. The non-return valve can be arranged, for example, in a mixing duct, an air intake duct and/or in an exhaust gas pipe of the heating appliance and/or in the connection area of the heating appliance to the heating system or between the heating appliance and a common flue gas discharge system of the heating system. The non-return valve can be designed such that it opens when a predetermined flow of fluid (air flow or mixture flow) through the heating appliance (or when a predetermined threshold value for the fluid flow is exceeded), and closes below a minimum flow (or when the threshold value is not reached) due to the non-return valve's own weight. Alternatively, or additionally, the non-return flap can also be spring-loaded to close.

The heating system is, in particular, a so-called multi-purpose system. This is usually characterised by the fact that several heating devices (from different dwellings) are connected to a common flue system (of a building), which is usually discharged into the environment via a chimney.

The heating device is, as a rule, a gas and/or oil heating device. In other words, this applies in particular to a heating device that is designed to burn one or more fossil fuels such as natural gas and/or oil, possibly with the addition of ambient air in a home, in order to generate energy for heating water, for example for use in the home. The heating device can be, for example, a so-called gas condensing boiler. As a rule, the heating device has at least one burner and a drive device that drives a mixture of fuel (gas) and combustion air (via a mixing channel of the heating device) into the burner. The exhaust gases resulting from the combustion can then be conducted via an (internal) exhaust gas pipe of the heating device to a flue gas extraction system (in a building). Typically several heating devices are connected to this flue gas extraction system.

In step a) a (deliberate and/or controlled) modification of an operating parameter of the heating apparatus is carried out, which can cause a variation in a fluid flow through the heating apparatus. The operating parameter can be, for example, a speed and/or a power of a driving device of the heating apparatus. The driving device can be, for example, a blower, a propeller, a compressor or the like. Preferably, the driving device is a blower. In other words, the fluid flow through the heating apparatus describes a fluid flow flowing (at least in some sections) through the heating apparatus, in particular a channel of the heating apparatus. The fluid flow can be characterized with reference to a volumetric flow rate and/or a mass flow rate. The fluid can be, for example, (combustion) air, fuel (in particular gas), off-gases and/or a fuel-air mixture.

The operating parameter can be changed, for example, by increasing or decreasing it from a predetermined initial value (constant) to a predetermined final value (constant). The increase or decrease can be carried out, for example, continuously and/or linearly. However, a sudden or abrupt change in the operating parameter is also conceivable. Furthermore, several different operating parameters can also be changed (at least partially in parallel or even simultaneously).

Alternatively or additionally, the operating parameter can also be changed such that a predetermined threshold value for the operating parameter and/or the fluid flow is exceeded or dropped below it. In principle, the operating parameter can also be increased or decreased continuously and/or linearly. In particular, the threshold value is precisely predetermined such that if the threshold value is exceeded, an existing non-return valve is opened and/or if the threshold value is dropped below it, an existing non-return valve is closed.

In step b) a measurement parameter is detected (or measured) which enables an inference to be made about the fluid flow through the heating device. The measurement parameter is usually detected within the heating device or at the heating device (e.g. between the heating device and the common flue gas discharge system). Detection is usually carried out by means of sensor detection or measurement. The measurement parameter can be, for example, a volume flow rate or a mass flow rate. In addition, the measurement parameter can also be an electrical signal which enables a (direct) inference to the magnitude of the volume flow rate or the mass flow rate of the fluid flow.

In step c) the presence of a non-return valve is recognised if the measurement parameter changes, at least for a certain period of time (during the modification of the operating parameter or immediately after the modification of the operating parameter), without showing a relationship with the modification of the operating parameter. In particular, the presence of the non-return valve is recognised if, during the modification of the operating parameter, the measurement parameter changes in a manner not proportional to the modification of the operating parameter and/or changes abruptly.

For example, the presence of the non-return gate can be inferred if the measurement parameter suddenly varies significantly (abruptly) during a continuous (in particular linear) modification (reduction or increase) of the operating parameter (i.e. it varies (decreases or increases) significantly faster than the operating parameter). In particular, a significant modification of the measurement parameter should be understood as a modification which is at least twice as large and/or faster than the modification of the operating parameter.

Alternatively or additionally, the presence of a non-return gate can be inferred if the measurement parameter does not change or essentially does not change after an increase (even if sharp) in the operating parameter to a value below a threshold value. In this connection, in particular the threshold value is defined precisely such that if the threshold value were to be exceeded, an existing non-return gate would open, which would then lead to a change in the operating parameter.

In step d), the heating device is switched to an event state and/or to a deactivated state if no non-return valve has been detected. In this connection, the heating device can also output a corresponding event message.

In an advantageous embodiment, it is proposed that the operating parameter is a speed of a drive device of the heating device. This advantageously allows the method to be carried out as simply and precisely as possible. In particular, it is a speed of a fan of the heating device.

In another advantageous embodiment, it is proposed to carry out step b) with a sensor of the heating apparatus. This advantageously contributes to the highest possible degree of automation of the process. In particular, the sensor is arranged and/or configured such that it can provide an electrical signal proportional to the fluid flow. This signal can be transmitted, for example, to a control unit and/or to evaluation electronics of the heating apparatus. The sensor can be, for example, a mass flow sensor, a differential pressure sensor or a sensor with a Pitot tube or the like.

In another advantageous embodiment, it is proposed that at least the operating parameter or the fluid flow be brought to a value below a threshold value and that the presence of the non-return valve be recognised by the measurement parameter falling abruptly (or significantly) or remaining at zero. Advantageously, this enables the non-return valve to be checked as quickly and easily as possible.

In this connection, it is particularly advantageous if the operating parameter and/or the fluid flow are increased to a value below a threshold value and if the presence of the non-return valve is recognised by the measurement parameter remaining at zero. "Remaining at zero" is here to be understood in particular as meaning that the measurement parameter remains at its initial value. In this case, the value is defined in particular such that if the threshold value is exceeded, an existing non-return valve would open.

In another advantageous embodiment, it is proposed to bring at least the operating parameter or the fluid flow from a value above a threshold value to a value below the threshold value and to detect the presence of the non-return valve by a sharp drop in the measurement parameter. This advantageously makes it possible to test the non-return valve in the most reliable way possible. The threshold value can be precisely predetermined such that if the threshold value is dropped, an existing non-return valve would close.

In this connection, it is particularly advantageous (as an alternative or additional) to reduce the operating parameter and/or the flow rate from a predetermined start value to a predetermined end value and to detect the presence of the non-return valve by a sudden or significant drop in the measured parameter. As a rule, the start value is predetermined so that an existing non-return valve opens (safely) when it is reached. In addition, the end value is usually specified so that an existing non-return valve closes (safely) when it is reached. If the start value and the end value (which are theoretically above or below a theoretical or possibly determined threshold value) are predetermined, it is not strictly necessary to specify the threshold value explicitly (e.g. in a control unit of the heating appliance).

It is possible to provide a computer program 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 the program is executed by a computer, make it possible to carry out a method described herein. There may be a machine-readable storage medium on which the computer program is stored. As a rule, the machine-readable storage medium is a computer-readable data carrier.

In another aspect, a control unit for a heating device is also proposed, which is designed to carry out a method presented here. For this purpose, the control unit may have, for example, a processor. In this connection, the processor may, for example, execute the method stored in a memory (of the control unit).

In another aspect, a heating device with a control unit is also proposed as presented here. The heating device is in particular a gas-fired heating device with a gas burner and a propellant device that can propel a mixture of gas and combustion air towards the gas burner.

In another aspect, it is also proposed to use a heating device of a heating system to check (the presence of) a non-return valve in the heating system. In particular, it is proposed to use a drive device and/or a sensor of the heating device to check the non-return valve or the presence of the non-return valve in the heating system. For this purpose, a heating device also described here is preferably used.

The details, features and advantageous implementations discussed in connection with the method may also appear in the control unit, heating apparatus and/or use presented herein, and vice versa. Accordingly, full reference is made to those implementations to characterize the features in greater detail.

The solution presented here and its technical context are explained in greater detail below using the 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 circumstances explained in or in connection with the figures and combine them with other components and/or conclusions from other figures and/or from the present description. By way of example and in schematic form:

Figure 1 shows a sequence of a procedure proposed here,

Figure 2 shows a heating apparatus proposed here, and

Figure 3 shows an illustration of parameter evolutions, which can result when carrying out a procedure presented here.

Figure 1 shows, by way of example and schematically, a sequence of a method proposed here. The method is used to check (the presence of) a non-return valve 1 in a heating system with at least one heating device 2. The sequence of steps a), b) and c) represented by blocks 110, 120 and 130 can occur during normal operation.

According to step a), in block 110 a modification of an operating parameter 3 of the heating apparatus 2 is generated, which can cause a variation in a fluid flow through the heating apparatus 2. According to step b), in block 120 a detection of a measurement parameter 4 is carried out, which allows an inference about the fluid flow through the heating apparatus 2. According to step c), in block 130 a recognition of the presence of the non-return valve 1 is carried out if the measurement parameter 4 evolves, at least for a time, without showing a relationship with the modification of the operating parameter 3.

Figure 2 shows, by way of example and schematically, a heating apparatus 2 proposed here. The heating apparatus 2 has a control unit 8 which is configured to carry out a method presented here.

The heating apparatus 2 (for example a gas-fired condensing boiler) is equipped with a burner system in which the gas from a gas supply channel 13 and the combustion air from an air intake channel 12 are combined in a mixing channel 11 upstream of a blower, which is an example of a blower device 5 here. This mixture is then blown by the blower 5 through the mixing channel 11 into a burner 9, where combustion then takes place. The flue gases resulting from the combustion are led via an inner flue gas pipe 10 to a gas discharge system, not shown here.

A non-return flap 1 is arranged in the mixing channel 11, which opens when there is a predetermined air or mixing flow (i.e. a predetermined threshold value) and closes below a minimum flow due to the weight of the non-return flap 1. Alternatively, such a non-return flap 1 could also be arranged in the air intake channel 12 or in the exhaust gas pipe 10. Alternatively or additionally, the non-return flap 1 could also be spring-loaded to close.

A sensor 6 is integrated in the air intake channel 12 to the gas-air mixing point 14, which sends an electrical signal proportional to the air flow to an evaluation electronics of the control unit 8. The sensor 6 can be a mass flow sensor, a differential pressure sensor or a sensor with a Pitot tube connection or the like. Detection is therefore carried out here, for example, with a sensor 6 of the heating unit 2.

Figure 3 shows, by way of example and schematically, an illustration of parameter developments over time which can result when carrying out a method presented here. The operating parameter 3 is here, by way of example, a speed of the drive device 5 of the heating device 2. In addition, by way of example, the operating parameter 3 is here brought from a value above a threshold value 7 to a value below the threshold value 7, and the presence of the non-return valve 1 is detected by the fact that the measurement parameter 4 drops sharply.

In the process, for example, when the burner 9 is first put into operation, the blower 5 is initially operated at a first speed 15, thereby generating a sensor signal 4. The fan speed is then brought to a second speed value 16, which is selected such that the air flow through the non-return valve 1 is so low that the non-return valve 1 falls into the "closed" position under its own weight. As soon as the non-return valve 1 is closed, the sensor signal 4a of the mass flow sensor drops abruptly to a value (close to) zero. If the non-return valve were not installed, the sensor signal 4b would decrease uniformly until it reaches the second speed value 16. In this case, the evaluation electronics of the control unit 8 outputs, for example, a corresponding error message on a display (not shown), and the evaluation electronics block the start of the heating unit 2.

As a precaution, it should be noted that the numerical terms ("first", "second" ...) used here serve primarily (only) to distinguish between several similar objects, quantities, characteristics or processes, i.e. in particular there is not necessarily any dependency or sequence order between these objects, variables, parameters or processes. If a dependency and/or sequence order is necessary, this is explicitly indicated here or becomes obvious to the person skilled in the art when studying the specifically described embodiment.

A method for testing a non-return valve in a heating system with at least one heating device, a control unit and a heating device for carrying out the method, and a use of a heating device are therefore provided here, which at least partially solve the problems outlined with reference to the prior art. In particular, the method, the control unit and the heating device, as well as the use, contribute at least to increasing the operational safety of a multiple-use system. In addition, the integration of a heating device into a multiple-use system can be simplified and carried out more safely.

List of reference symbols

1 non-return gate

2 heating device

3 operating parameter

4 measurement parameter

5 driving device

6 sensor

7 threshold value

8 control unit

9 burner

10 tube for gas outlet

11 mixing channel

12 air suction channel

13 gas supply channel

14 mixing point

15 first number of revolutions

16 second number of revolutions

Claims (9)

1. A method for checking the presence of a non-return valve (1) in a heating installation with at least one heating device (2), the non-return valve being configured to prevent backflows of flue gases, comprising at least the following steps which are carried out when a heating device (2) is integrated into the heating installation and/or during the commissioning of such a heating device (2): a) modifying an operating parameter (3) of the heating device (2), which may cause a modification of a fluid flow through the heating device (2), b) detecting a measurement parameter (4) that allows an inference about the fluid flow through the heating apparatus (2), c) recognize the presence of a non-return gate (1) if the measurement parameter (4) evolves, at least for a time, without showing a relationship with the modification of the operating parameter (3), d) causing the heating device (2) to switch to an incident state and/or to a deactivated state if no non-return valve (1) has been recognised. 2. Method according to claim 1, wherein the operating parameter (3) is a number of revolutions of a driving device (5) of the heating apparatus (2). 3. Method according to claim 1 or 2, wherein step b) is carried out with a sensor (6) of the heating apparatus (2). 4. Method according to one of the preceding claims, wherein at least the operating parameter (3) or the fluid flow is brought to a value below a threshold value (7) and the presence of the non-return valve (1) is recognized by the fact that the measurement parameter (4) drops abruptly or remains at zero. 5. Method according to one of the preceding claims, wherein at least the operating parameter (3) or the fluid flow is brought, starting from a value above a threshold value (7), to a value below the threshold value (7) and the presence of the non-return valve (1) is recognized by the fact that the measurement parameter (4) drops abruptly. 6. Method according to one of the preceding claims, wherein the non-return valve (1) is arranged in a mixing channel (11) of the heating apparatus (2). 7. Control unit (8) for a heating device (2) in a heating installation with at least one heating device (2) and a non-return valve for preventing backflows of flue gases, the control unit being configured to carry out a method according to one of claims 1 to 6. 8. Heating apparatus (2) with a control unit (8) according to claim 7. 9. Use of a heating apparatus (2) according to claim 8 in a heating installation for checking a non-return valve (1) of the heating installation.