CN115597235A

CN115597235A - Heating system and method for operating a heating system

Info

Publication number: CN115597235A
Application number: CN202210779936.3A
Authority: CN
Inventors: 詹尼克·博克
Original assignee: Viessmann Climate Solutions SE
Current assignee: Viessmann Climate Solutions SE
Priority date: 2021-07-07
Filing date: 2022-07-04
Publication date: 2023-01-13
Also published as: DE102021207162B3

Abstract

The invention provides a method for operating a heat generator (2) for heating a heat transfer medium. The method comprises the step of operating a combustion process in a burner (3) of a heat generator (2). The heat generated by the burner (3) is transferred in a heat exchanger (7) to a heat transfer medium. The combusted exhaust gas is discharged via an exhaust passage (5). The exhaust gas temperature (T) in the exhaust passage (5) is measured with a temperature sensor (4) arranged in the exhaust passage (5). The operating state of the heat generator (2) is adjusted or controlled as a function of the measured exhaust gas temperature (T).

Description

Heating system and method for operating a heating system

Technical Field

The invention relates to a heating system and a method for operating a heating system.

Background

DE 197 35 079A1 discloses an air heater for a motor vehicle, which air heater operates independently of the engine and comprises a burner, a combustion chamber and a heat exchanger, wherein the heat transfer medium of a pot-shaped base heat exchanger flows around the combustion chamber, which is closed at one end by the burner and at the other end adjacent to the base of the heat exchanger with a space therebetween, and an overheat detection sensor is arranged on the heat exchanger and in the hottest region of the heat exchanger, i.e. in the base region of the heat exchanger, and is configured as a reference or dome temperature sensor, by means of which the reference or dome temperature of the heat exchanger is monitored by a controller and, if necessary, limited; and, a flame detection sensor preferably located in the exhaust. The signal is also monitored by the controller.

DE 20 2008 015 206U1 describes a retrofit kit for a boiler for heating buildings and/or industrial water, comprising a gas-water heat exchanger, a connection for connecting the gas-water heat exchanger to a boiler exhaust port, and an exhaust manifold for connecting the heat exchanger to an exhaust pipe. A fan that affects the flow of exhaust gas in the exhaust branch pipe is provided in the exhaust branch pipe. Due to the fluid connection between the connection piece, the part of the heat exchanger through which the gas flows, the exhaust branch and the exhaust pipe, the fan in the exhaust branch also influences the exhaust gas flow in the other areas mentioned. By dimensioning the fan accordingly, a desired exhaust flow can be obtained and thus also the pressure, in particular at the connection, can be influenced.

DE 10 2017 214 069a1 relates to a method for operating a thermal system comprising a plurality of components, in particular a boiler. Based on the detected contamination values for the thermal system and/or the at least one component, an expected arrival time value is determined, at which a predeterminable critical contamination value for the heating system and/or the at least one component is reached or exceeded for the first time. The expected arrival time value is written to memory.

A typical heating system comprises a heat generator with a burner, in particular a gas burner, which operates with gaseous fuel and air. In the combustion chamber of the burner, a flame body is provided, from which gas or a gas-air mixture enters the combustion chamber. After the gas-air mixture is ignited using the ignition electrode, a flame forms around the flame body. The spatial extent of the flame is also referred to below as the reaction zone. The combustion process takes place in a reaction zone. The output of the burner depends substantially on the amount of fuel supplied and on the air available for combustion, in particular on the ratio between them. Exhaust gas from the combustion is discharged via an exhaust passage.

The combustion chamber is equipped with a heat exchanger through which the hot exhaust gases or reaction gases (heating gases) transfer heat to a heat transfer medium, such as water. The heat exchanger may be arranged, for example, helically around the reaction zone. In heat generators using condensation technology, in addition to the measurable temperature at which the gas is heated, the heat of condensation is also used to heat the heat transfer medium. This is achieved by passing the exhaust gases produced during combustion through a heat exchanger until the water vapour contained therein condenses.

In order to control the combustion process and ensure safe operation of the heat generator, among other things, the temperature of the exhaust gas in the exhaust channel is measured and monitored. In particular, when the exhaust temperature is too high, there may be a risk of damaging the exhaust passage. The burner may be forced to shut down in a locked manner when, for example, a predetermined maximum temperature is exceeded in the exhaust stream. Then, for example, a restart is possible only after a manual reset of the burner. Such a safe shut-down may result in a loss of comfort for the user of such a heat generator or the inhabitants of the building in which the heating system including the heat generator is installed, since no hot water is initially available and no heating output is available. This may result in, for example, cooling of the building, possibly resulting in freezing. For example, when there is also no warm water available, only a cold water shower may be used.

Disclosure of Invention

It is an object of the present invention to overcome the problems known in the prior art and to provide an improved method of operating a heat generator compared to the prior art. This object is achieved by a method for operating a heat generator for heating a heat transfer medium. The method comprises the following steps: operating a combustion process in a burner of the heat generator, transferring heat generated by the burner to the heat transfer medium in a heat exchanger, discharging exhaust gas generated by combustion via an exhaust channel, measuring an exhaust gas temperature in the exhaust channel using a temperature sensor arranged in the exhaust channel, controlling an operating state of the heat generator in dependence on the measured exhaust gas temperature. Shutting down the combustion process in the combustor when the measured exhaust temperature reaches a predetermined maximum temperature. When the measured exhaust temperature reaches a predetermined first limit temperature, reducing the output of the combustor in accordance with a deviation of the measured exhaust temperature from the first limit temperature. The first limit temperature is lower than the maximum temperature. When the reduced output of the burner is lower than or equal to a limit output, a warning message is generated and output. Furthermore, the object is achieved by the method, the heat generator and the heating system according to the invention. Other aspects of the invention will be apparent from the accompanying drawings and the following description of exemplary embodiments.

The object of the invention is to optimize a method for operating a heat generator or a heating system in order, where possible, not to exhibit the disadvantages described above. In particular, contamination or calcification of the heat exchanger of the heat generator will be detected. Furthermore, when contamination or calcification of the heat exchanger is detected, the operation of the heat generator is adjusted, thereby avoiding possible malfunction of the heat generator.

For example, the exhaust gas temperature may increase due to the heat exchanger absorbing less heat from the exhaust gas. In particular, when the flow of the heat transfer medium through the heat exchanger is limited, for example due to contamination or calcification of the heat exchanger, a reduced heat transfer to the fluid heat transfer medium flowing in the heat exchanger may occur.

Generally, the exhaust temperature may increase as the heat transfer coefficient of the heat exchanger decreases. In particular, the heat transfer coefficient of the heat exchanger can be reduced by contamination or calcification. The heat transfer coefficient quantifies the ability of the heat exchanger to transfer heat from combustion to the heat transfer medium.

Therefore, the degree of contamination of the heat exchanger directly affects the heat transfer function of the heat exchanger between the heating gas and the heat transfer medium. The higher the degree of contamination, the more difficult it is for the heat exchanger to transfer heat to the heat transfer medium, where "poor" heat transfer means slower and/or lost heat transfer. This may result in, for example, a heat generator increasing the burner output to reach a specified flow temperature. This may therefore result in a greater increase in the exhaust temperature of the heated gas.

The process of increasing the heat exchanger contamination can be slow and continue for a period of weeks to months until a significant degree of contamination is reached, which represents a value of importance for the operation of the heat generator. Furthermore, the contamination of the heat exchanger may be caused by dirt particles and/or calcification in the heat transfer medium. If no countermeasures are taken, the degree of contamination will generally increase over time.

Without interfering with the operation of the heat generator or the operation of the burner, the exhaust temperature will continue to rise as the pollution or calcification increases. For safety reasons, the burner is normally shut down in a locked manner when a predetermined maximum temperature in the exhaust gas is reached or exceeded. Then, the restart is only possible after the manual reset. However, in the case of non-maintenance of the heat exchanger, the exhaust gas temperature may in time exceed the maximum temperature again.

To prevent such a locked shut-down and associated loss of hot water delivery, a method according to the first aspect of the invention is proposed which gradually reduces the output of the burner as soon as the exhaust gas temperature reaches a limit temperature below the maximum temperature.

Furthermore, according to the second aspect of the present invention, the degree of contamination of the heat exchanger should be determined indirectly based on the decrease in the output of the burner, so that maintenance of the heat exchanger can be started as early as possible before the heat generator fails.

The present invention is described in detail below using exemplary embodiments.

Drawings

Further advantageous developments are described in more detail below with reference to exemplary embodiments shown in the drawings, to which, however, the invention is not restricted.

In the figure:

FIG. 1 illustrates a heating system according to an exemplary embodiment of the present invention;

FIG. 2 illustrates an example of a time profile of burner output and exhaust gas temperature in a heating system according to an exemplary embodiment; and

fig. 3 shows a flow chart illustrating a method according to an exemplary embodiment of the invention.

Detailed Description

In the following description of the preferred embodiments of the present invention, the same reference signs refer to the same or similar components.

Fig. 1 shows a heating system 1 according to an embodiment of the invention. The heating system 1 is located, for example, in a building (e.g., a residential building or an office building) and includes, for example, a gas condensing boiler as a heat generator 2 that heats a fluid heat transfer medium (e.g., water). The heat generator 2 is not limited to the gas condensing boiler, but hereinafter, only the gas condensing boiler will be described as an example.

The heat generator 2 may be any heat generator, in particular a condensing boiler using gas or oil as fuel. The heat generator 2 may also be another type of heat generator for heating a fluid heat transfer medium, wherein the exhaust gas from the combustion reaction is used to heat the heat transfer medium.

A fluid heat transfer medium is used to transport heat. Usually a gas or a liquid is used as the heat transfer medium. Water is commonly used as the heat transfer medium. The heated water can for example flow directly from a tap in an open water circuit in the building as water. Furthermore, the heated water may be used in a closed heating loop. For storing hot water, the heating system 1 may in particular comprise a hot water tank (not shown).

In fig. 1, the heating system 1 includes a network 40. However, the network 40 itself is not necessarily a component of the heating system 1 itself, but may be used only by the heating system 1, so that the individual components of the heating system 1 communicate with one another, i.e. are able to exchange data.

The heating system 1 comprises a data processing device 20, which is communicatively connected to a network 40 by means of a suitable interface. The data processing device 20 comprises a (local) storage device 21 for storing data and a computing device 22 for processing data.

The data processing device 20 may be arranged locally, for example in the same building as the heating system 1, or at a geographical distance. In particular, the data processing device 20 or the computing device 22 may be a server connected to the control device via the internet or other network, such as a Local Area Network (LAN) or a Wide Area Network (WAN), a computing cluster, or the like.

The storage device 21 may be a local storage device of the data processing device 20. Additionally or alternatively, the memory device may be implemented as, for example, cloud storage or network storage. The cloud storage or network storage may be communicatively connected to the data processing device 20, in particular the computing device 22, and the control device 10 of the heating system 1 or a plurality of control devices of a large number of heating systems via the internet or other network 40. Accordingly, data exchange between the control device 10 and the data processing device 20 (the computing device 22 and the storage device 21) can take place via the respective network 40. For this purpose, the individual components each have a corresponding interface.

An advantage of the data processing device 20 connected via the internet is that it is possible to receive, store and process data from a large number of heating systems 1, which may be located at a geographical distance from each other (for example in different buildings). This may involve a number of similar or different heating systems 1 with the same, similar or different heat generators 2. In particular, it may be advantageous to evaluate data from a large number of identical or similar heating systems 1, which heating systems 1 in particular have identical or similar heat generators 2, in order to perform a specific statistical evaluation of the received and stored data for a specific type of heat generator.

Another advantage of the data processing device 20 connected via the network 40 is that data from the heating system 1 can be evaluated centrally, irrespective of how many heating systems 1 are connected to the data processing device 20 via the network 40.

In addition to or instead of the data processing device 20, the cloud 30 may be connected to the network 40 via a suitable interface and may receive and/or store data from the control device 10 and the data processing device 20. The data processing device 20 and the control device 10 can access the cloud 30 and retrieve data via the network 40. The cloud 30 may be configured similar to the data processing device 20 for storing and/or processing data.

The heat generator 2 is used for heating a heat transfer medium and comprises a burner 3, wherein a fuel-air mixture is combusted in the burner 3 to generate heat, which is transferred to the heat transfer medium through a heat exchanger 7. The heat generator 2 further comprises an exhaust channel 5 for discharging exhaust gases. A temperature sensor 4 for measuring the exhaust gas temperature T is arranged in the exhaust passage 5.

The heating system 1 or the heat generator 2 further comprises a control device 10 for controlling the operating state of the heat generator 2, in particular in accordance with predetermined control parameters. The control parameters include, for example, a target flow temperature, a specified on-time of the heat generator 2, a target storage unit temperature of an optional heat storage unit (not shown) and/or a maximum output (modulation) of the heat generator 2 or of the burner 3 of the heat generator 2.

In particular, some control parameters may be preset in the control device 10 as heating curves so that the weather compensation operation of the heat generator 2 can be performed according to the outside temperature of the building. To this end, the control device 10 may be connected to an external temperature sensor (not shown) and may receive a measured value of the external temperature.

The control device 10 is connected to the network 40 by a suitable interface. Via the network 40, the control device 10 can communicate with the data processing device 20 and/or with the cloud 30 and/or with a mobile terminal device 50 of a user or operator of the heating system 1 and can exchange data, i.e. send data (e.g. measured values regarding the operating state of the heat generator 2) to the data processing device 20 and/or receive data (e.g. control parameters) from the data processing device 20.

The control device 10 and/or the data processing device 20 and/or the cloud 30 are particularly configured such that they perform the method according to the invention, which method will be described further below. The various steps of the method may thus be performed by the control device 10, the data processing device 20 and/or the cloud 30, depending on the requirements or design of the heating system.

The control device 10 can periodically transmit a large number of measured values, in particular temperature measured values, to the data processing device. Furthermore, the mass flow or the volume flow of the heat transfer medium can also be measured and transmitted. For example, the control device 10 may send a large number of measurements about the operating state of the heating system 1 or the operating state of the heat generator 2 to the data processing device 20 or the cloud 30 several times per second, several times per minute, several times per hour or several times a day. Thus, a large number of measured values can be generated and can be used to monitor and/or evaluate the temporal distribution of the operating state of the heating system 1 and/or of the heat generator 2.

During normal operation of the burner 3, a combustion process takes place, wherein a fuel-air mixture is combusted. The resulting hot fuel gas is used to heat the heat transfer medium so that the heat generated by the burner 3 is transferred to the heat transfer medium at the heat exchanger 7.

The heat exchanger 7 is a spiral heat exchanger as shown in fig. 1. Such a heat exchanger 7 comprises, for example, a tube with a circular, oval or rectangular cross section through which a heat transfer medium flows. The heat exchanger 7 surrounds the combustion chamber of the burner 3. In the combustion chamber of the burner 3, a flame body 8 is arranged, into which the fuel or the fuel-air mixture is introduced from the flame body 8. After ignition of the fuel-air mixture by the ignition electrode 4, a flame is formed in the reaction zone 6 surrounding the flame body 8.

In the condensing boiler, in addition to pure heat of the exhaust gas, the heat of condensation of water vapor in the exhaust gas is also used to heat the heat transfer medium. Therefore, a drain pipe (not shown) for condensed water may be provided at the bottom of the burner 3.

The output of the burner 3 may be adjusted or controlled, for example, by adjusting or controlling the amount of fuel and/or air. The function of a conventional ordinary burner or condensing boiler is well known to those skilled in the art and therefore will not be described in detail.

Exhaust gas resulting from the combustion may be discharged from the combustion chamber of the combustor 3 through an exhaust passage 5. A temperature sensor 4 for measuring the exhaust gas temperature T is arranged in the exhaust passage 5. The temperature sensor T may be connected to the control apparatus 10 and output a measured value of the exhaust gas temperature T to the control apparatus 10.

The control device 10 can control the operating state of the heat generator 2 or the burner 3 depending on the measured exhaust gas temperature T. For example, the control device 10 shuts down the combustion process in the burner 3 when it is detected that the measured exhaust gas temperature T reaches a predetermined maximum temperature. In particular, the shut-down may be performed in a locked manner, which means that the burner 3 can only be restarted after a manual reset.

The specified maximum temperature of the exhaust gas can be selected as appropriate depending on the configuration of the heat generator 2, for example, preferably 120 ℃, more preferably 110 ℃ for a condensing boiler, wherein these values are not to be understood as limiting. The maximum temperature may be determined, for example, in consideration of the standard for safe operation of the combustor 3. In particular, the maximum temperature may be set according to the heat resistance of the exhaust passage 5.

In order to avoid the above-mentioned locking shut-off when the maximum temperature is reached or exceeded, a first limit temperature T1 of the exhaust gas is specified. The first limit temperature T1 is lower than the maximum temperature. When the measured exhaust temperature reaches or exceeds the first limit temperature T1, the control apparatus 10 decreases the output of the combustor 3. As a result of the decrease in output, the exhaust gas temperature in the exhaust passage 5 will decrease.

The first limit temperature T1 is preferably used to initiate a control intervention, in particular to reduce the burner output by the control device 10. Therefore, the method described below is only activated when the exhaust gas temperature first reaches or exceeds the first limit temperature T1.

According to an exemplary embodiment, the first limiting temperature T1 is preferably 5K lower than the maximum temperature, more preferably 10K lower than the maximum temperature, particularly preferably 15K lower than the maximum temperature, for example 95 ℃, 100 ℃ or 105 ℃.

The control apparatus 10 may determine the reduction output of the burner 3 based on the deviation of the measured exhaust temperature T from the first limit temperature T1, or simply reduce the burner output by a predetermined amount. In a preferred embodiment, the reduced burner output may be determined by calculation from the measured exhaust temperature T. In another preferred embodiment, the reduced combustor output may be determined, for example, by subtracting a predetermined amount. Thus, the combustor 3 is operated with a reduced output. Since the first limit temperature T1 is lower than the maximum temperature, the shut-down of the burner 3 can be avoided.

For example, the burner output may be gradually decreased. The size of the steps may be pre-specified, for example preferably in steps of 0.1%, 0.5%, 1%, 2% or 5% of the maximum output, wherein the normal operation of the burner 3 is without a reduction in output at 100% maximum output. Adjusting the burner output in dependence on the deviation of the measured exhaust gas temperature T from the first limit temperature T1 can be understood as a control loop between the burner output and the exhaust gas temperature T. Therefore, the control apparatus 10 can control the burner output to a specified exhaust gas temperature T.

As an alternative or in addition to the reduction of the output (regulating operation), the burner 3 may also be operated in a duty cycle depending on the deviation of the measured exhaust gas temperature T from the first limit temperature T1. In duty cycle operation, the combustor is operated at a specified output at specified time intervals. Increasing the off time or decreasing the on time reduces the amount of heat generated. Since the temperature changes relatively slowly, it is also possible to prevent the maximum temperature being reached by adjusting the regulation of the burner 3.

Preferably, the output of the burner 3 is reduced until the measured exhaust temperature T is lower than the second limit temperature T2. The second limit temperature T2 is lower than the first limit temperature T1. In this way, the combustor output may be controlled based on the exhaust temperature T.

The second limiting temperature T2 is preferably 10K below the maximum temperature, more preferably 5K below the maximum temperature, particularly preferably 1K below the maximum temperature, for example 95 deg.C, 90 deg.C or 85 deg.C. The second limit temperature T2 is also referred to as a safety temperature. When the measured exhaust temperature T reaches or falls below the safe temperature T2, the burner output no longer decreases.

In a preferred embodiment, the control device 10 can increase the burner output slightly again even when the safety temperature T2 is not reached, as long as the subsequently measured exhaust gas temperature T remains below the first limit temperature T1.

According to a preferred embodiment, the control device 10 reduces the output of the burner 3 at most to a predetermined minimum output P1. The minimum output P1 may for example correspond to a burner output where a minimum comfort level is just reached, in particular a minimum temperature of the plant water or hot water or a minimum temperature in the hot water storage unit. The minimum output P1 is preferably 60%, more preferably 50%, particularly preferably 45% of the maximum output.

Preferably, the control apparatus 10 generates and outputs the warning information when the reduced output of the combustor 3 is less than or equal to the output limit P2. The output limit P2 is a limit value of the output of the combustor 3, and may be preferably 70%, more preferably 75%, and particularly preferably 80% of the maximum output.

The generated warning information may preferably be output to a mobile terminal device 50 of a user or operator of the heat generator 2 and/or on a display device of the heat generator 2. The purpose of the warning message is to warn a user or operator of the heating system 1 that a control intervention has taken place, wherein the output of the burner 3 has decreased. The warning information may preferably also contain the current reduced output of the burner 3 and/or the measured exhaust gas temperature T and/or the time scheduled or required for maintenance of the heat generator 2.

Preferably, the control device 10 or the data processing device 20 and/or the cloud 30 calculates the degree of pollution of the heat exchanger 7 from the deviation of the reduced output from the maximum output of the burner 3. Accordingly, the warning message may contain an indication of the calculated degree of contamination of the heat exchanger 7.

According to a preferred embodiment, the measured exhaust gas temperature T and the output of the burner 3 are transmitted to the data processing device 20 and/or the cloud 30, which are communicatively connected to the heat generator 2 via a network 40. The transmitted values of the exhaust gas temperature T and the output of the burner 3 may then be stored in the storage device 21 of the data processing device 20 and/or in the cloud 30.

The steps of determining a reduced output of the burner 3 or reducing a burner output and/or calculating a degree of pollution of the heat exchanger 7 and/or generating a warning message may be performed, inter alia, by the computing device 22 of the data processing device 20 and/or the cloud 30. Thus, the data processing device 20 and/or the cloud 30 may perform one or more functions of the control device 10.

In the above description of the exemplary embodiment and the preferred embodiment, the individual method steps are performed by the control device 10. However, the present invention is not limited thereto. In particular, the data processing device 20 and/or the cloud 30 and/or the mobile terminal device 50 may also perform individual or all method steps in which data, measured values, operating parameters and the like are received, calculated, established, determined and/or evaluated. The control device 10 and at least one of the data processing device 20, the cloud 30 or the mobile terminal 50 may also perform redundant steps. Advantageously, the distributed processing of data can be performed accordingly.

The control device 10 preferably periodically transmits data, such as measured values and/or operating parameters of the burner 3, in particular the measured exhaust gas temperature T and the current output of the burner 3, to the data processing device 20 and/or the cloud 30 and/or the mobile terminal 50 via the network 40. In particular, the data processing device 20 may store data received from the control device 10 in the storage device 21. Additionally or alternatively, the cloud 30 may receive and store the transmitted data.

Prior to transmission, the data may be stored locally and pre-processed for transmission by the control device 10. In this case, for example, a corresponding time identification may be added to the data. In addition, the data format may be converted and/or the data to be transmitted may be encrypted. In particular, the control device 10 may periodically transmit the setting output of the burner 3 and/or the switching time of the burner 3 to the data processing device 20 or the cloud 30.

From the stored data, in particular the set output of the burner 3 and the exhaust gas temperature T, the calculation device 22 can calculate the degree of pollution of the heat exchanger 4. Thereby, the time at which maintenance of the heat generator 2 is required can be calculated and preferably output as an instruction to the mobile terminal device of the user or operator.

The mobile terminal device 50 may be, for example, a smartphone, a tablet computer, a laptop computer, or a desktop computer. In particular, the indication may be displayed using an internet browser or sent via an information service or SMS. The mobile terminal device 50 may be connected to the network 40 via a suitable interface and exchange data with the control device 10, the data processing device 20 and/or the cloud 30 via the network.

An application with a graphical user interface may be running on the mobile terminal device 50 allowing a user or operator of the heating system 1 to read data from the heating system 1. Further, the application may be configured to receive data input from a user or operator and transmit the data to the control device 10, the data processing device 20, and/or the cloud 30.

The heating system 1 according to the invention can thus detect or predict the degree of contamination of the heat exchanger 4 and ensure the comfort of the user through control interventions. In particular, switching off the heating system 1 can be avoided by adjusting the output of the burner 3.

In particular, the pollution of the heat exchanger 4 can be detected based on the variation of the reduced output of the burner 3 over time together with the measured exhaust gas temperature T, wherein the measurement is made over a longer period of time, for example several months or more than a year, to avoid seasonal fluctuations. As the fouling of the heat exchanger 4 increases over a specified period of time (e.g., one year), it is generally determined that the characteristic drop in combustor output.

In a preferred embodiment of the invention, the increase in calcification or contamination of the heat exchanger 4 can be determined by analyzing the time series. To this end, the combustor output may be plotted as a series of data points over time. This series of data points can be compared to a corresponding historical time profile or time profile of other heating systems in which calcification or contamination of the heat exchanger has also occurred. The evaluation may thus preferably be performed in the cloud 30 or by the data processing device 20.

In particular, the stored data may also be evaluated by algorithms on the computing cluster, where the algorithms are trained by machine learning using large amounts of field data (e.g., measurements from a large number of heating systems). In this case, the computing cluster may be a preferred embodiment of the computing device 21 or may also communicate with the data processing device 20, the cloud 30 and/or the control device 10 via the network 40.

Information on the degree of water hardness of the region may also be taken into account in the calculation to distinguish between dirt and calcification and to check the rationality thereof. Further, the change over time in the burner output of the heat generator of the first heating system in zone a may be compared to the change over time in the burner output of the (same) heat exchanger in the second heating system in zone B.

The degree of local water hardness may also be taken into account in particular when calculating the remaining expected service life of the heat exchanger 4. Since the degree of water hardness can vary greatly between different zones, different service lives of the heat exchanger 4 are required for the different zones. The information about the degree of water hardness may be received, for example, by the control device 10 and/or the data processing device 20, for example, via the network 40.

Calcification or contamination of the heat exchanger may depend on a number of factors. The invention enables identification of the actual calcification or contamination and the rate of calcification or contamination. In addition to the control intervention in the operation of the burner 3, as described above, the maintenance information may be output to the mobile terminal 50 of the user or operator of the heating system 1, so that the maintenance of the heating system 1 or the burner 3 may be performed in a timely manner.

The method according to the invention will now be explained again using the schematic diagram shown in fig. 2. In fig. 2, the output P (continuous curve) of the combustor 3 and the exhaust gas temperature T (broken line) measured by the temperature sensor 4 in the exhaust passage 5 are plotted with time. Fig. 2 thus shows an example of the time distribution of the burner output P and the exhaust gas temperature T when using the method according to the invention.

At time t0, the heat generator 2 is turned on and the burner output P rises to 100%. When the burner 3 is operated at full load, the exhaust gas temperature T rises and reaches a first predetermined limit temperature T1 at time T1. In order to prevent the exhaust gas temperature T from rising further and possibly reaching a maximum temperature T _MAX The control apparatus 10 decreases the burner output P by a fixed amount Δ P.

After the waiting time Δ T elapses, it is determined at time T2 that the exhaust temperature T is higher than the second limit temperature T2. In response to this, the control apparatus 10 decreases the burner output P by the fixed amount Δ P again.

After the waiting time Δ T, it is determined again at time T3 that the exhaust temperature T is higher than the second limit temperature T2. In response to this, the control apparatus 10 decreases the burner output P by the fixed amount Δ P again.

After the waiting time Δ T, it is determined at time T4 that the exhaust temperature T is lower than the second limit temperature T2. Therefore, there is no need to further reduce the burner output P.

The output reduction amount Δ P may be, for example, 5% of the maximum output. The waiting time Δ t may be 15 seconds, for example. The first limit temperature T1 is, for example, 100 ℃. The second limit temperature T2 is, for example, 95 ℃.

The limit output P2 and the minimum output P1 are also shown in fig. 2. The minimum output P1 is, for example, 50%. The burner output P should not be reduced further by the method according to the invention, since otherwise there is a risk of the user of the heating system 1 losing comfort. For example, it is no longer possible to provide sufficiently hot water. In this case, maintenance is urgently required.

For example, in fig. 2, the limit output P2 is 80% and is not reached with every 3-fold reduction of 5% in burner output P. When the output limit P2 is reached or fallen below, a warning may be output to the mobile terminal 50 of the user or operator of the heating system 1.

For example, the warning may contain information about the current reduced burner output P. The indication may also contain information about possible contamination of the heat exchanger 7 of the heat generator 2. As mentioned above, the degree of pollution of the heat exchanger 7 can be calculated from the reduction of the burner output P.

The values given in fig. 2 are exemplary and should not be construed as limiting. These values can be modified as necessary to suit the heat generator in question.

In the following, the method according to the invention is described again with reference to the exemplary flowchart shown in fig. 3. At the beginning of the method, in step S1, the output P of the burner 3 is first increased to 100%, and the exhaust gas temperature T in the exhaust passage 5 is measured by the temperature sensor 4.

In step S2, the control device 10 compares the measured exhaust gas temperature T with a specified maximum temperature T _MAX Making a comparison, e.g. T _MAX May be 115 deg.c. When the exhaust temperature T reaches the maximum temperature T _MAX When this occurs (yes in step S2), the burner 2 is immediately turned OFF in a lock manner (OFF). Only after manual reset can the restart.

When the exhaust temperature T is lower than the maximum temperature (no in S2), it is next checked whether the exhaust temperature T reaches or exceeds a first limit temperature T1, for example, 100 ℃ (step S3). If the exhaust temperature T is lower than T1 (NO in S3), the method returns to the first step S1. As long as the exhaust gas temperature T remains below the first limit temperature T1, there is no control intervention and the burner 3 can operate normally at 100% output.

When the exhaust gas temperature T is as high as the first limit temperature T1 or higher than the first limit temperature T1 (yes in step S3), the burner output P is decreased by a fixed amount Δ P in step S4. The fixed amount Δ P may be, for example, 5%.

In the next step S5, it is checked whether the burner output P, now reduced, is less than or equal to the limit output P2. For example, the limit output P2 may be 80%. This limit output P2 is also referred to as "warning output".

When the burner output P is less than or equal to the warning output P2 (yes in S5), a warning instruction is issued to the user or operator of the heating system 1 in step S6. The warning indication may for example contain information about the calculated contamination of the heat exchanger 7 of the heat generator 2. Thus, the warning indication will call the user or operator attention to the need to maintain the heat generator 2 as the heat exchanger 7 becomes more and more contaminated to prevent further reduction of the output in the burner 3. .

When the burner output P is greater than the warning output P2 (no in S5), the method continues with step S9. After a waiting time Δ T of, for example, 15 seconds, the exhaust gas temperature T is determined again in step S9. In the next step S10, the exhaust gas temperature T measured in S9 is compared with a second limit temperature T2 of, for example, 95 ℃. When the exhaust gas temperature T is equal to or lower than the second limit temperature T2 (yes in S10), there is no need to further lower the burner output P at this time. The method returns to step S1.

As long as the exhaust gas temperature T does not continue to rise at this point, the method remains in cycle S1, where no in S2 and no in S3. Only when the exhaust gas temperature T rises further (e.g. due to an increase in pollution of the heat exchanger 7) the reduction of the burner output P starts again (e.g. if yes in S3).

However, when it is determined in S10 that the exhaust gas temperature T is greater than the second limit temperature T2 after the waiting time Δ T (no in S10), the method returns to step S4 and the burner output P is further decreased.

After the warning indication is generated in S6, the burner output P is further checked in step S7. That is, the burner output P should not be less than the minimum output P1. The minimum output P1 is, for example, 50% of the maximum output. If the reduced output P- Δ P is less than or equal to P1 (YES in S7), it is set as a new output of the combustor P1 in S8.

The method then returns to step S1 to continue checking whether T has been reached _MAX And performs a safety shutdown if necessary. Further, a new warning indication that the minimum output P1 is reached may be issued to the user or operator in S8.

When the burner output P in S7 is still greater than P1 (no in S7), the method continues as described above in step S9.

The features disclosed in the foregoing description, in the claims and in the accompanying drawings may be of significance to the implementation of the invention in its various configurations both individually and in any combination.

Claims

1. A method for operating a heat generator (2) for heating a heat transfer medium, comprising the steps of:

operating a combustion process in a burner (3) of the heat generator (2);

transferring heat generated by the burner (3) to the heat transfer medium in a heat exchanger (7);

discharging exhaust gas resulting from the combustion via an exhaust passage (5);

measuring an exhaust gas temperature (T) in the exhaust gas channel (5) using a temperature sensor (4) arranged in the exhaust gas channel (5);

controlling the operating state of the heat generator (2) as a function of the measured exhaust gas temperature (T);

shutting down the combustion process in the burner (3) when the measured exhaust temperature (T) reaches a predetermined maximum temperature;

reducing the output of the burner (3) as a function of the deviation of the measured exhaust gas temperature (T) from a predetermined first limit temperature (T1) when the measured exhaust gas temperature (T) reaches the first limit temperature (T1);

wherein the first limit temperature (T1) is lower than the maximum temperature; and

when the reduced output of the burner (3) is lower than or equal to a limit output (P2), a warning message is generated and output.

2. A method according to claim 1, wherein the output of the burner (3) is reduced until the measured exhaust gas temperature (T) is less than a second limit temperature (T2), the second limit temperature (T2) being less than the first limit temperature (T1).

3. The method of claim 1 or 2, wherein

The output of the burner (3) is reduced to a specified minimum output (P1) at most.

4. The method of claim 1, wherein

The warning information is output to a mobile terminal device (50) of a user or operator of the heat generator (2) and/or on a display device of the heat generator (2).

5. The method of claim 1, further comprising:

calculating the degree of pollution of the heat exchanger (7) from the deviation of the reduced output from the maximum output of the burner (3).

6. The method of claim 1, wherein

The warning information comprises an indication of the calculated contamination level of the heat exchanger (7).

7. The method of claim 1, further comprising:

transmitting the measured exhaust gas temperature (T) and the output of the burner (3) to a data processing device (20) communicatively connected to the heat generator (2) via a network (40) and/or to a cloud (30) connected to the network (40); and

storing the transmitted exhaust gas temperature (T) and the transmitted output of the burner (3) in a storage device (21) of the data processing device (20) and/or in the cloud (30), wherein

The steps of reducing the output of the burner (3) and/or calculating the degree of pollution of the heat exchanger (7) and/or generating warning information are performed by a computing device (22) of the data processing device (20) and/or the cloud (30).

8. A heat generator (2) for heating a heat transfer medium, comprising:

a burner (3);

a heat exchanger (7) for transferring heat generated by the burner (3) to the heat transfer medium;

an exhaust passage (5) for discharging exhaust gas;

a temperature sensor (4) provided in the exhaust passage (5) for measuring an exhaust gas temperature (T); and

a control device (10) for controlling the operating state of the heat generator (2), wherein

The control device (10) is configured to perform the method according to one of claims 1 to 7.

9. Heat generator (2) according to claim 8, wherein

-the control device (10) is communicatively connected via a network (40) to a mobile terminal device (50) of a user or operator of a data processing device (20) and/or a cloud (30) and/or the heat generator (2); and

the control device (10) and the data processing device (20) and/or the cloud (30) are configured to perform the method according to claim 1.

10. A heating system (1) comprising:

a network (40);

heat generator (2) according to claim 9, connected to said network (40)

A data processing device (20) connected to the network (40) and comprising a storage device (21) for storing data and a computing device (22) for processing data; and/or

A cloud (30) connected to the network (40); and/or

A mobile terminal (50) connected to the network (40).