METHOD FOR DETECTING DAMAGE TO THE HOUSING OF A BLOWER OF A HEATING APPLIANCE, COMPUTER PROGRAM PRODUCT, CONTROL AND REGULATION DEVICE, HEATING APPLIANCE AND USE OF A DETECTED VALUE

Description

[0001] The invention relates to a method for detecting damage to the housing of a blower of a heating device, a computer program product, a control and regulation device, a heating device and a use of a detected quantity.

[0002] Heating appliances generally use sensors for parameters such as temperature, light or heat radiation, pressure, volume flow, and the like to control the appliances and ensure their safe operation. An important function is detecting the presence of a stable flame (a so-called flame detector), another is adjusting the combustion air-to-fuel gas ratio (lambda value) to ensure stable and environmentally friendly combustion. Furthermore, design and control measures are implemented to prevent, as reliably as possible, flame flashbacks from the combustion chamber, where combustion is intended to take place, into the supply system of unburned air-fuel gas mixture.Nevertheless, such events, which can have different causes and processes, cannot be completely ruled out, especially when using hydrogen-containing fuel gas, which causes higher flame speeds and releases more energy per volume than conventional fuel gas mixtures.

[0003] In the event of a flashback or reignition, a pressure surge occurs in the supply system, which can propagate to the blower that circulates the air-fuel mixture. This can deform an impeller (possibly made of plastic), particularly due to the heat generated simultaneously. The consequences can be even more serious if a flashback also ignites the mixture within the blower housing. In this case, a pressure surge can propagate deep into the housing, deforming its walls or causing leaks to the surrounding environment. Typical blower housings are made of die-cast and / or sheet metal components, and joints, welds, or connections are especially vulnerable to damage from a pressure surge.

[0004] JP H09 72539 A describes a blower with a blower control device that can detect a blockage in an air passage of the blower. However, the method cannot be used to determine damage resulting from a flame flashback.

[0005] The object of the present invention is to detect damage to the housing of the blower of a heating system, in particular caused by previous flame flashbacks (which may not be registered by conventional sensors), in order to be able to take appropriate safety measures if necessary.

[0006] Furthermore, the invention should not significantly increase the complexity of a heating device, should require only minor structural changes to the equipment, and should allow for easy integration into an existing production process.

[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] A method for detecting damage, namely a leak, in the housing of a blower of a heating appliance contributes to solving the problem, wherein the blower supplies a mixture of air and fuel gas to a combustion chamber of the heating appliance, and at least one quantity dependent on the condition of the housing is recorded, and when a limit value is reached (in particular exceeded and / or fallen below), damage is inferred from the quantity.

[0009] The heating appliance in question is, in particular, a gas-fired boiler designed to burn a fuel gas (such as natural gas or hydrogen) with the addition of ambient air and to generate heat energy, for example, to heat a heat transfer fluid in a heating circuit or to provide hot water. The heating appliance may specifically be a condensing boiler. It typically has a combustion chamber and a fan that draws a mixture of fuel gas and combustion air into the combustion chamber. The combustion products can then be discharged through an exhaust system.

[0010] A burner may be located in the combustion chamber, often comprising perforated metal sheets that can be flat, curved, or cylindrical. The mixture of fuel gas and combustion air can flow through the perforated sheets and subsequently be ignited and burned. If the combustion flame speed is greater than the mixture's outflow velocity, a flashback can occur into the fuel gas / combustion air ducts. Such a problem can also occur during ignition, or if the temperature of the perforated sheet on the side facing away from the combustion chamber is higher than on the side facing the combustion chamber.

[0011] As a result of a described flame flashback or reignition, the ductwork for the fuel gas / combustion air mixture, as well as the blower impeller and the blower itself, can be damaged. The invention is particularly useful for detecting damage to the blower housing, i.e., damage that allows the ingress of outside air and / or the escape of the fuel gas / combustion air mixture—in other words, a leak in the housing. Frequently, a flame flashback results in damage to the blower housing on the pressure side, which can be accompanied by an escape of the fuel gas / combustion air mixture. In other words, this invention specifically describes a method for detecting the ingress of outside air and / or the escape of fuel gas and / or combustion air from the blower housing and / or a leak in the blower housing.In particular, it is possible to distinguish such damage to the blower housing from, for example, other types of damage, such as unexpected flow congestion, blockages, etc.

[0012] According to an advantageous embodiment, if the measured quantity exceeds an upper or lower limit, damage can be inferred. The upper and lower limits can define or restrict a reference range for the measured quantity, within which an intact housing can be assumed. Including an upper and lower limit can increase the reliability of the method proposed here, although this should be assessed in relation to the specific quantity being measured.

[0013] According to an advantageous embodiment, the size that depends on the state of the housing can in particular be at least one of the following.

[0014] The quantity dependent on the condition of the housing can be the flow rate (gas volume flow or gas mass flow) in the pipe leading to the burner. This can be determined, for example, by a flow sensor (air mass flow sensor). If the blower housing is defective (leaky), the pressure drop that the blower must overcome decreases, and thus a higher flow rate can be delivered at the same housing speed. Therefore, if a limit value is exceeded, a damaged housing can be inferred.

[0015] However, in the case of a significantly damaged housing where pressure build-up by the impeller is no longer possible, a very low flow rate can occur at the same rotational speed. Therefore, according to a further advantageous embodiment, a damaged housing can also be inferred if a lower limit value for the flow rate is not reached.

[0016] The condition of the housing can affect the electrical power consumption of the blower. This can be determined, for example, by detecting a control signal, particularly a PWM signal (pulse-width modulated signal). A PWM signal can be expressed, for instance, as a percentage of the blower's rated power. Thus, a defective housing and the associated decrease in pressure loss can lead to lower power consumption by the blower, and consequently, to a power consumption below a minimum threshold.

[0017] However, as explained above, a significantly damaged housing, where pressure build-up by the impeller is no longer possible, can also result in very high power consumption, since the control system attempts to regulate to a nominal flow rate that cannot be achieved due to the damage to the housing. Therefore, damage to the housing can also be indicated by exceeding an upper limit for the blower's power consumption.

[0018] The parameter dependent on the condition of the housing can (preferably) also be the thermal output of the heater. If the heater's blower housing is damaged, the amount of gas supplied can decrease due to lower control pressure at the mixing unit (e.g., a Venturi device), and consequently, so can the heater's thermal output. The heater's thermal output can be determined, for example, by measuring the flow and return temperatures of the heater. P th = m ˙ × c p × T Vor − T R ü ck with P th thermal output ṁ Mass flow heat transfer fluid CP specific heat capacity of heat transfer fluid, and T Forward, T Back Flow and return temperature

[0019] The thermal output of the heating device determined in this way can be compared with the thermal output expected based on the fan speed, and in the event of a deviation (outside a tolerance range), in particular a fall below the expected thermal output, it can be concluded that the fan housing is damaged.

[0020] The parameter dependent on the condition of the casing can (preferably) be the heating time of a heating water circuit. This heating water circuit can be a heating circuit connected to the heating appliance, in which a heat transfer fluid can circulate. Advantageously, the heating water circuit can be closed, in particular, via a heat exchanger located within the heating appliance for domestic hot water supply, since with such an internal heating circuit, a good comparability of the determined heating time is ensured due to the absence or only minor external influences. With a damaged casing and the associated decrease in the thermal output of the heating appliance, as described above, the heating time of the heating water circuit (for a defined temperature difference) can increase, thus exceeding the expected heating time as a limit value.

[0021] The variable dependent on the condition of the housing can (preferably) be a differential pressure measured at two points along the fuel gas or combustion air lines, upstream and downstream of the blower. Pressure sensors can be positioned at these two points for this purpose.

[0022] According to an advantageous embodiment, several quantities can also be recorded and, if necessary, evaluated, thus excluding other circumstances that lead to exceeding or falling below a limit value of a quantity.

[0023] Advantageously, the aforementioned parameters are often already recorded in heating devices as part of the regulation and control system, thus enabling the invention to be implemented purely as a software-based implementation.

[0024] According to an advantageous embodiment, in addition to the quantity dependent on the state of the housing, the rotational speed of the blower can be detected and at least one limit value can be given as a function of the rotational speed of the blower.

[0025] According to an advantageous embodiment, continued operation and / or ignition of the heating system can be (automatically) prevented if the detected parameter exceeds or falls below a certain limit value. In other words, if damage to the housing of the heating appliance's blower is detected, the operation of the heating appliance can be stopped and restarting it prevented, so that restarting can only be carried out by a person familiar with the system.

[0026] According to an advantageous embodiment, information about a detected damaged housing can be displayed via a display device and / or made available for retrieval via a network and / or sent as a message. The display device can be a display device of the heating appliance or that of a (wirelessly) connected device, such as a mobile phone. The network can be, in particular, the internet. Advantageously, a message via the network or the provision of the information can inform an operator or servicing company, enabling them to independently schedule and carry out a service appointment.

[0027] Another aspect is the proposal of 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 proposed here.

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

[0029] In addition, a control unit for a heating appliance (particularly as disclosed herein) is proposed, configured to carry out a method proposed herein. For this purpose, the control unit may, for example, include and / or have a processor. In this context, the processor may, for example, execute the method stored in a memory (of the control unit). Advantageously, operating data (for example, upper and / or lower limit values ​​of the detected quantity(ies)) for carrying out a method presented herein may also be stored in the memory of the control unit. Furthermore, the control unit may be configured to detect the quantity dependent on the state of the housing of the heating appliance's blower.

[0030] According to another aspect, a heating device (especially as revealed here) is also proposed, comprising a control and regulating device as proposed here.

[0031] Another aspect is used to select a use for a captured quantity: a volume flow determined downstream of the blower, a power consumption of the blower, a thermal output of the heater, a heating time of a heating water circuit connected to the heater, a differential pressure between two points upstream and downstream of the blower This device is proposed for detecting leaks in the housing of a fan in a heating appliance. Its use is specifically designed to quickly detect damage caused by a flame flashback or reignition and, if necessary, to take appropriate safety measures. It can also be used to identify or confirm the occurrence of a flame flashback or reignition.

[0032] The details, features, and advantageous configurations discussed in connection with the process may also occur in the computer program, control and regulation device, hot water supply system, and / or its use presented here, and vice versa. In this respect, full reference is made to the explanations provided therein for a more detailed characterization of the features.

[0033] This document describes a method for detecting damage to the housing of a heater's blower, a computer program (product), a control and monitoring device, a heater, and the use of a measured parameter, all of which at least partially solve the problems described with reference to the prior art. In particular, the method for detecting damage to the housing of a heater's blower, the computer program product, the control and monitoring device, the heater, and the use of a measured parameter contribute, at least in part, to providing a simple and reliable way to detect damage to the housing of a heater's blower and thus to making the operation of a heater safer.

[0034] Furthermore, the invention can be implemented particularly easily and cost-effectively, as usually only an adjustment of computer software is necessary. Therefore, the invention is also suitable for retrofitting existing heating appliances.

[0035] 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 limited by the exemplary embodiments shown.

[0036] It should be noted in particular that the figures, and especially the depicted proportions, are only schematic. They show: Fig. 1 : a heating device suggested here, and Fig. 2-5 : Parameter profiles that can occur when carrying out a procedure proposed here.

[0037] Fig. 1Figure 1 shows an exemplary and schematic representation of a proposed heating device 1. This device can have an air supply 4 for combustion air, in which a mass flow sensor 16 can be arranged for measuring the intake mass flow of combustion air. A Venturi device 15 can be arranged in the air supply 4, which adds a quantity of gas corresponding to a control pressure generated by the combustion air mass flow. A fuel gas valve 5 can also be arranged in the fuel gas supply.

[0038] Downstream of the Venturi device 15 in the air supply direction 18, a blower 2 with a housing 8 can be arranged, which can supply the mixture of fuel gas and combustion air to a burner 3 via a mixture channel 12. The blower 2 can be connected to a speed control 19. A heat exchanger 13 can be arranged at the burner 3, which can transfer the heat generated during combustion to a heating water circuit 14. The heating water circuit 14 can include a flow 26 with a temperature sensor 6 and a return 27 with a temperature sensor 11, via which consumers such as radiators or underfloor heating systems can be connected.The heating circuit 14 can be closed for hot water supply by means of a three-way valve 24 via a heat exchanger 25 arranged between the flow 26 and return 27, whereby the heating time of the heating circuit 14 closed via the heat exchanger 25 is very comparable, since there are no or only minor external influences. A mass flow sensor 9 can also be arranged in the heating water circuit 14, which can detect the mass flow of the heat transfer medium (usually heating water).

[0039] Downstream of the burner 3, an exhaust pipe 10 can convey combustion products to an exhaust system. A control and regulating unit 7 of the heating appliance 1 can be electrically connected to the speed control 19 of the fan 2, the fuel gas valve 5, the mass flow sensor 16 in the air supply 4, the mass flow sensor 9, the temperature sensor 6 in the flow line, the temperature sensor 11 in the return line of the heating water circuit 14, the three-way valve 24, and a network 17 (in particular the Internet).

[0040] Fig. 2 shows exemplary and schematic parameter curves of a mass flow ṁ Combustion air as a function of time t, determined by the mass flow sensor 16 in the air supply 4 of the heater 1 during a start-up process of the heater 1. A detected value 20 lies between a lower limit 21 and an upper limit 22, thus indicating an intact housing 8 of the blower 2.

[0041] Fig. 3shows exemplary and schematic parameter curves of an electrical power consumption P el as a function of time t at constant speed of the blower 2. The detected quantity 20 lies between a lower limit 21 and an upper limit 22, thus indicating an intact housing 8 of the blower 2.

[0042] Fig. 4 shows exemplary and schematic parameter curves of a thermal power output P th as a function of time t at constant rotational speed n of the blower 2. The thermal power can be determined using the relationship P th = ṁ × CP × ( T Forward - T Back ) have been determined. The measured quantity 20 (or determined thermal output) is above a lower limit value 21, which also indicates that the housing 8 of the blower 2 is intact.

[0043] Fig. 5The figure shows, by way of example and schematically, parameter curves of a heating time t until a target temperature 23 of the heating water circuit 14 is reached. A recorded quantity 20 (recorded heating time) lies below an upper limit value 22, which also indicates that the housing 8 of the blower 2 is intact. Reference symbol list

[0044] 1 Heater 2 Blower 3 Burner 4 Air supply 5 Combustion gas valve 6 Flow temperature sensor 7 Control unit 8 Housing 9 Domestic hot water circuit mass flow sensor 10 Exhaust pipe 11 Return temperature sensor 12 Mixing channel 13 Heat exchanger 14 Heating water circuit 15 Venturi device 16 Air supply mass flow sensor 17 Network 18 Flow direction 19 Speed ​​control 20 Measured value 21 Lower limit 22 Upper limit 23 Target temperature 24 Three-way valve 25 Domestic hot water heat exchanger 26 Flow 27 Return

Claims

1. Method for detecting damage to a housing (8) of a fan (2) of a heating device (1), namely a leak or leakage of the housing (2), wherein the fan (2) supplies a mixture of air and fuel gas to a burner (3) of the heating device (1), and at least one variable (20) dependent on the condition of the housing (8) is detected and, when a limit value (21, 22) is reached by the variable (20), damage to the housing (8) is inferred.

2. Method according to claim 1, wherein when an upper limit value (22) or lower limit value (21) is reached by the detected variable (20), damage to the housing (8) of the fan (2) is concluded.

3. Method according to claim 2, wherein in addition to the variable (20) dependent on the condition of the housing (8), a rotational speed of the fan (2) is detected and an upper limit value (22) and / or lower limit value (21) is given as a function of the rotational speed.

4. Method according to one of the preceding claims, wherein the detected variable (20) is at least one of the following variables (20) dependent on the rotational speed of the fan (2): - a determined mass flow or volume flow of the fan (2), - a power consumption of the fan (2),5. Method according to one of the preceding claims, wherein the detected variable (20) is a thermal output of the heating device (1).

6. Method according to one of the preceding claims, wherein the measured variable (20) is a heating-up time of a heating water circuit (14) connected to the heating device (1).

7. Method according to one of the preceding claims, wherein the detected variable (20) is a differential pressure between two points upstream and downstream of the fan (2).

8. Method according to one of the preceding claims, wherein continued operation and / or ignition of the heating device (1) is prevented when the detected variable (20) has reached a limit value (21, 22).

9. Method according to one of the preceding claims, wherein information about a detected damaged housing (8) is displayed via a display device and / or made available for retrieval via a network (17) and / or sent as a message.

10. Control and regulation device (7) of a heating appliance (1), wherein a fan (2) supplies a mixture of air and fuel gas to a burner (3) of the heating appliance (1), designed to carry out a method according to one of claims 1 to 9.

11. Heating device (1) comprising a fan (2) which can supply a mixture of air and fuel gas to a burner (3) of the heating device (1), with a control and regulation device (7) according to claim 10 and means for carrying out a method according to one of claims 1 to 9.

12. Computer program product comprising instructions that cause a heating device (1) according to claim 11 to carry out a method according to one of claims 1 to 9.

13. Use of at least one detected variable (20) selected from: - a volume flow or mass flow determined downstream of the fan (2), - a power consumption of the fan (2), - a thermal output of the heating device (1), - a heating-up time of a heating water circuit (14) connected to the heating device (1), and / or - a differential pressure between two points upstream and downstream of the fan (2) for detecting damage, namely a leak or impermeability, in a housing (8) of a fan (2) of a heating device (1).