How to operate a gas heater

Abstract

The present invention relates to a method for operating a gas heater, in particular a gas heater for providing central heating and / or domestic hot water, in particular a gas boiler, in particular a condensing boiler, comprising the following steps: supplying gas and a fuel gas into a mixing chamber of the gas heater and supplying the mixed gas from the mixing chamber to a burner of the gas heater, measuring a differential pressure per unit of time and / or presenting a sensor signal to a control unit in order to determine a gas amount defined by volume per unit of time or mass per unit of time before the gas is supplied to the mixing chamber, measuring a differential pressure per unit of time and / or presenting a sensor signal to a control unit in order to determine a fuel gas amount defined by volume per unit of time or mass per unit of time before the fuel gas is supplied to the mixing chamber, and determining whether at least one operating condition of the gas heater is fulfilled based on the determined gas amount and / or the determined fuel gas amount.

Description

[Technical Field]

[0001] The present invention relates to a method for operating a gas heater. Furthermore, the present invention relates to a gas heater and a boiler equipped with such a gas heater. Furthermore, the present invention relates to a heating system having such a gas heater and / or boiler, and to the use of such a gas heater and / or boiler. Furthermore, the present invention relates to a computer program product. [Background technology]

[0002] Several gas heaters are known from the prior art. A gas heater typically comprises a mixing chamber in which a gas, particularly air, is mixed with a fuel gas. The gas mixture is supplied to the burner of the gas heater. Such a gas heater can be used, for example, in a boiler. The boiler comprises a heat exchanger in which water is heated by the heat supplied by the gas heater.

[0003] U.S. Patent No. 5,486,107 is effective for a wide range of fuel compositions and, in terms of accurately determining the amount of oxygen required for the complete combustion of a given type and amount of fuel, with respect to the same degree of accuracy as the error of the measured parameters from which the values ​​are derived, the improved determination of fuel properties including calorific value and oxygen demand, as well as the Wobbe index or Wobbe number, for more accurate fuel metering and combustion control, a method for determining thermophysical or thermochemical property values ​​of natural or other hydrocarbon gaseous fuel gas using a microbridge sensor, wherein the microbridge sensor is fluid-coupled to receive the fuel and present a signal value, thermal conductivity, k of the fuel; a step of applying the fuel to a static microbridge sensor to obtain a thermal conductivity value of the fuel; a step of applying the fuel to a static microbridge sensor to obtain a specific heat value of the fuel, wherein the microbridge sensor is fluid-coupled to receive the fuel and present a signal value, specific heat cp of the fuel; a step of correcting the values ​​of the signals k and cp using a plurality of measured sensor signal values ​​k and cp obtained at different temperatures so that these values ​​can be processed to obtain corresponding values ​​of the fuel under reference conditions; the c ps The step of processing multiple measured different temperature values ​​of cp in order to obtain the value of dcp / dT under the reference conditions, the k s To obtain the value of dk / dT under the reference conditions, k s The disclosed method includes the steps of processing multiple measured different temperature values, and processing the values ​​obtained in the previous step in a processor to obtain desired characteristics of the fuel according to a relationship selected from the following: JPEG0007923763000001.jpg49167 In the formula, Ys is the higher calorific value, H is the oxygen demand, D is the Wobbe index, Wo is the relative density or specific gravity, ρ is the absolute density, ρ a I; I (inert substance); Z (compressibility coefficient); R (critical compression ratio) c ; Represents the desired thermophysical or thermochemical parameter selected from viscosity or η; A0, A1...A i n is a constant or coefficient.i , m i , p i , q i , r i , s i each represents an exponent with a value ranging from -20 to 20, inclusive of 0; the number of terms i ranges from 1 to 15; k s and c ps represent their respective values under predetermined standard conditions of temperature and pressure; x s represents dk / dT under the standard conditions; Y s represents dc p / dT under the standard conditions; T s represents the temperature under the standard conditions; P s represents the absolute pressure under the standard conditions.

[0004] U.S. Patent No. 6,561,791 is directed to providing an adjustment device for a gas burner that avoids the drawback of limited application range, such as an operating range limited by the interaction between low actuating force resulting from interference effects and operating tolerances, or other limitations, and discloses an adjustment system for a gas burner in which a fuel gas flow and a combustion air flow are guided to the burner. The fuel gas flow is adjusted in accordance with the pressure of the combustion air flow. A differential pressure sensor is arranged between the fuel gas flow and the combustion air flow. The sensor generates an electronic signal that is used to adjust a gas valve for the fuel gas.

[0005] International Publication No. 2020 / 148,434 of this brochure aims to provide a less complex but precise method for adjusting the gas mixture of a fuel gas-operated heating system, which is also robust against external influences such as dust, and discloses a method for controlling the gas mixture formed from the gas and fuel gas of a fuel gas-operated heating system, wherein the gas mixture is generated by amounts of gas and fuel gas supplied by a first actuator and a second actuator, respectively, and then mixed; a micro thermal gas mixture sensor that detects at least one material property of the gas mixture is supplied with the gas mixture and continuously transmits a sensor signal dependent on the particular gas mixture to a control unit; the control unit compares the detected sensor signal to a set value of the sensor signal, and if the detected sensor signal deviates from the set value sensor signal, it activates at least one of the first and second actuators, thereby adjusting the gas mixture by increasing or decreasing the amount of gas and / or increasing or decreasing the amount of fuel gas until the set value of the sensor signal is achieved.

[0006] German Utility Model No. 2020 / 18,101,271 relates to providing a fuel-gas-operated heater in which the type of fuel gas is determined before the heater is started and used in the starting process, and discloses a fuel-gas-operated heater with an electronic gas-air system, the heater comprising: at least one blower for conveying a volume flow of air; a gas supply unit with a gas actuator for controlled supply of fuel gas; a burner; an ignition unit for igniting the burner; a sensor located in the gas supply unit and flowing with the fuel gas; and a control device for determining the gas mass flow of the fuel gas and adjusting the volume flow of air conveyed by at least the blower and the gas actuator, a. The sensor is designed as a gas mass sensor for determining the mass of the fuel gas and the physical properties assigned to that mass. b. The gas mass sensor can measure the physical properties of the fuel gas and transmit them to the control unit. c. The type of fuel gas can be determined by the control device from the measured physical characteristics of the fuel gas. d. The control device of the gas control element can adjust the first starting gas mass flow according to a specific type of fuel gas, which is lower than the ignition limit of the fuel gas of a specific type of fuel gas. e. The supplied gas mass flow can be increased at a constant air volume flow rate, starting from the initial gas mass flow, until it exceeds the ignition range for a particular type of fuel gas, through ignition attempts by the ignition unit. f. During the ignition attempt, the burner ignition can be monitored and recorded.

[0007] European Patent No. 3,683,500 relates to a method for adjusting the gas mixture of a fuel gas-operated heating device, which detects changes in the properties of the gas supplied to the fuel gas and adjusts control parameters in a target manner, disclosing a method for adjusting the gas and a gas mixture formed from the gas and fuel gas of a fuel gas-operated heating device, wherein the gas mixture is generated by supplying and mixing a gas amount by a first control element and a fuel gas amount by a second control element, and a micro thermal gas sensor and a gas mixture sensor are used, the sensor signals are relayed to a controller, and when the detected sensor signal of the gas sensor changes, the newly detected sensor signal of the gas sensor is compared with a reference value measured in the laboratory and stored in a table of values ​​in the controller, from which a target value of the sensor signal of the gas mixture sensor is determined without changing the mixing ratio of the gas mixture composed of the fuel gas and gas.

[0008] European Patent No. 2,574,918 aims to demonstrate a method for a simple and cost-effective upgrade of appropriate gas flow measurement techniques to a high-precision gas quality sensor, which is a first sensor for determining the thermal conductivity or density of a gas and physical gas properties (γ), e.g., density (ρ) or heat capacity (cp) or mass flow or volume flow or a combination of these variables. By doing so, a method for determining the physical gas properties of a gas mixture for correlation of variables related to the combustion of the gas mixture is disclosed, in the formula The image is JPEG0007923763000003.jpg15154, and at least the micro thermal sensor is exposed to the gas flow, and the thermal conductivity (λ) of the gas mixture is measured separately using the micro thermal sensor.

[0009] International Publication No. 2019 / 185,181 aims to provide a regulating device that can achieve reliable and accurate control of the mixing ratio between a first gas and a second gas, even when there are large differences between those gas flow rates over a wide dynamic range of absolute gas flow rates, and discloses a regulating device comprising a first sensor S1 for determining one or more thermal parameters of a gas mixture, the sensor S1 being positioned in a common conduit downstream of the mixing region and upstream of the fan so that the sensor S1 is exposed to the gas mixture.

[0010] The control device receives a sensor signal from the first sensor S1. Based on the sensor signal, the control device derives a control signal to adjust the opening of the fuel control valve. The control device further adjusts the power to operate the fan. Additional sensors may be provided in the air conduit and / or fuel conduit. For example, a second sensor S2 is provided in the air conduit upstream of the mixing region. In addition, or alternatively, a third sensor S3 is provided in the fuel conduit downstream of the fuel control valve and upstream of the mixing region. Similar to the first sensor S1, the second sensor S2 and / or the third sensor S3 are also advantageously protected from direct exposure to their respective gas flows by placing each sensor in a recess at the end of the wall of their respective conduit and / or by protecting each sensor with a gas-permeable membrane. Sensor S1 operates to determine the thermal conductivity λ of the gas mixture, the thermal diffusivity D of the gas mixture, and the temperature T of the gas mixture in the common conduit downstream of the mixing region. Sensor S2 operates to determine the thermal conductivity λ, thermal diffusivity D, and temperature T of the air in the air conduit upstream of the mixing region.

[0011] The air pressure pair is determined from these quantities. The air pressure pair or air density determined from the signal of sensor S2 can be used as an additional diagnostic parameter. In particular, the air pressure pair or air density can be used to detect fan blockage or malfunction. For example, the air pressure or density can be monitored continuously or periodically during the operation of the regulating device. Changes in air pressure or density while the fan is operating at a constant fan output may indicate blockage or fan malfunction. Determining the air pressure or density from the signal of sensor S2 is possible during the normal operation of the regulating device. Sensor S3 operates to determine the thermal conductivity λ fuel, thermal diffusivity D fuel, and temperature T fuel of the fuel gas in the fuel conduit downstream of the fuel control valve and upstream of the mixing region. The mixing ratio x uses the values ​​of λ mixing determined by sensor S1, λ air determined by sensor S2, and λ fuel determined by sensor S3. The determination is made based on JPEG0007923763000004.jpg9166. WO 2019 / 185181 A1 further discloses that it is possible to further measure the flow rate of air in an air conduit, the flow of fuel in a fuel conduit, or the flow of a gas mixture in a common conduit using a mass flowmeter. In this way, WO 2019 / 185181 A1 determines the absolute heating power of the gas mixture delivered to the gas burner. The mass flow rate can be used to control a fan so as to adjust the heating power. [Prior Art Document] [Patent Document]

[0012] [Patent Document 1] U.S. Patent No. 5,486,107 Specification [Patent Document 2] U.S. Patent No. 6,561,791 Specification [Patent Document 3] WO 2020 / 148434 A1 pamphlet [Patent Document 4] German Utility Model No. 202018101271 Specification [Patent Document 5] European Patent No. 3,683,500 Specification [Patent Document 6] European Patent No. 2,574,918 Specification [Patent Document 7] WO 2019 / 185181 A1 pamphlet [Summary of Invention] [Problem to be Solved by Invention]

[0013] In conventional electronic air-fuel ratio control systems, the control unit of the gas heater controls the heat load of the gas heater by controlling the ratio of air to fuel gas. Since the flame signal depends on the composition of the mixed gas, the ratio of air to fuel gas can be controlled based on the ionization signal. Therefore, the gas heater can internally adapt to fuel gases of the same family. However, known gas heaters cannot be used for fuel gas mixtures containing more than 95 mol% of hydrogen. In particular, when the fuel gas is or contains hydrogen in an amount exceeding 95 mol%, the ionization signal cannot be used to adapt the mixed gas to the composition required for the burner to provide the required output. Therefore, conventional gas adaptation systems require the use of a sufficient amount of natural gas to utilize the ionization signal, and thus such systems cannot perform combustion of 95 mol% or more hydrogen. [Means for Solving the Problems]

[0014] An object of the present invention is to provide a method for operating a gas heater that can be applied to various types of fuel gases or mixtures of fuel gases. In particular, the gas heater should be adaptable to various types of fuel gases or mixtures of fuel gases, including hydrogen-containing fuel gases, and increased emissions or poor efficiency caused by inaccurate mixing of air and fuel gas should be avoided. Furthermore, the method should also avoid the heater failing to start or experiencing flashback due to an inaccurate air-fuel ratio.

[0015] The object is achieved by a method for operating a gas heater, in particular a gas heater for providing central heating and / or for providing domestic hot water, in particular a gas boiler, in particular a condensing boiler, supplying air and fuel gas into a mixing chamber of the gas heater, and supplying mixed gas from the mixing chamber to a burner of the gas heater, Before the gas is supplied to the mixing chamber, the steps include measuring the differential pressure per unit time and / or presenting the sensor signal to the control unit in order to determine the amount of gas determined by volume per unit time or mass per unit time. Before the fuel gas is supplied to the mixing chamber, the steps include: measuring the differential pressure per unit time and / or presenting the sensor signal to the control unit in order to determine the amount of fuel gas determined by volume per unit time or mass per unit time, and This is resolved by a method that includes [a specific method].

[0016] Another object of the present invention is to provide a gas heater that can be used with various types of fuel gases or mixtures of fuel gases.

[0017] The objective is solved by a gas heater comprising: a mixing chamber for mixing gas and fuel gas; a burner located downstream of the mixing chamber and capable of supplying the mixed gas from the mixing chamber; a first sensor for providing a sensor signal to a control unit for measuring the differential pressure per unit time and / or for determining the amount of gas, which is determined by the volume or mass per unit time of the gas supplied to the mixing chamber; a second sensor for providing a sensor signal to the control unit for measuring the differential pressure per unit time and / or for determining the amount of fuel gas, which is determined by the volume or mass per unit time of the fuel gas supplied to the mixing chamber; and a control unit adapted to determine whether at least one operating condition of the gas heater is met based on the determined amount of gas and / or the determined amount of fuel gas.

[0018] According to the present invention, it has been recognized that by determining whether at least one operating condition of the gas heater is met based on the determined gas amount and / or determined fuel gas amount, it is possible to adjust the gas-to-fuel gas ratio so that the burner can supply the required output in safe operation, even when the hydrogen concentration in the fuel is high, 95 mol% or more. In particular, it is possible to supply a mixed gas having a gas-to-fuel gas ratio corresponding to a predetermined gas-to-fuel gas ratio. This is when at least one or all of the operating conditions are met.

[0019] The predetermined gas-to-fuel gas ratio of the gas mixture may depend on the operation of the gas heater, particularly the burner. This ratio can be determined in the laboratory and stored in the gas heater's electrical memory. In particular, the electrical memory can store the gas-to-fuel gas ratio covering all burner operations, from minimum to maximum load. The electrical memory may be part of the control unit.

[0020] Therefore, when a high concentration of hydrogen is present in the fuel gas, it is possible to determine the gas-to-fuel gas ratio of the mixed gas flowing out of the mixing chamber, independently of the ionization signal. Thus, the range of fuel gas compositions that can be used in the gas heater is wider than in known embodiments. Furthermore, in embodiments of the present invention, the gas quantity and fuel gas quantity are always known and can always be controlled in a way that is advantageous for safety reasons, especially when hydrogen is used as or as part of the fuel gas.

[0021] A further advantage of the present invention is that the gas and fuel amounts can be set to prevent flashback. Flashback occurs when the gas mixture velocity is less than the flame velocity, causing the flame to traverse upstream toward the burner deck and even across the burner deck toward the burner.

[0022] Fuel gases can be natural gas, methane, ethylene, propane, butane, coal gas, biogas, mixtures thereof, and mixtures thereof further containing hydrogen, or hydrogen, especially pure hydrogen. Pure hydrogen is present if the fuel gas contains at least 98 mol% hydrogen.

[0023] The gas can be air.

[0024] The control unit is an electrical control unit. Furthermore, the control unit is adapted to receive electrical sensor signals and output electrical control signals. The control unit may comprise at least one processor and / or a printed circuit board.

[0025] The sensor is, for example, a flow sensor. The flow sensor can be a sensor that measures differential pressure. In particular, the sensor can be a mass flow sensor or a volumetric flow sensor. Furthermore, the sensor can be a thermal sensor, a thermal anemometer sensor, an ultrasonic flow sensor, a magnetic flow sensor, a Coriolis mass flow sensor, and / or an optical sensor. The sensor can be an electrical sensor or an electronic sensor.

[0026] The mixed gas is the output gas that exits the mixing chamber. The mixed gas may include both gas and fuel gas. Alternatively, the mixed gas may consist only of gas if fuel gas is not introduced into the mixing chamber.

[0027] To determine the amount of gas supplied to the mixing chamber, the first sensor is located upstream of the mixing chamber. The second sensor is also located upstream of the mixing chamber. Hereafter, the terms “downstream” and “upstream” refer to the direction of gas flow from the gas heater fan to the burner, or the direction of fuel gas flow from the fuel gas valve to the burner.

[0028] If the gas is air, the gas source corresponds to the surrounding air drawn in by the fan. The fuel gas can be stored in a fuel gas tank, gas line, or gas grid, or it can be generated in situ by an electrolytic cell or the like.

[0029] The burner can be a premixed burner. Premixing means supplying a mixture of fuel gas and other gases to the burner. The combustion system can be an electronic combustion control system or a pneumatic combustion control system.

[0030] The burner can operate between minimum and full load. The ratio of full load to minimum load can be at least 4. The ratio of gas to fuel gas in the mixture supplied to the burner can be less than 4 for low load and less than 2 for full load, with a minimum of 1 for both.

[0031] According to embodiments of the present invention, gas and fuel gas are supplied into the mixing chamber after a heat demand is requested. A heat demand may be requested for the need for heat, particularly when hot water is needed in a household environment. Furthermore, the heating process can be performed when at least one operating condition, in particular when all operating conditions are met. The heating process may be igniting a gas heater or changing the output of a burner. The word “perform” means that the heating process can be started or a heating process that has already been started can be continued.

[0032] The gas heater may be equipped with an actuator for setting the gas flow rate. The control unit can be configured to control the actuator for setting the gas flow rate if the operating conditions of the gas heater are not met. The operating conditions may include checking whether the determined gas flow rate corresponds to a predetermined gas flow rate. As mentioned above, the predetermined gas flow rate depends on the operation of the burner.

[0033] The actuator can optionally be incorporated into a fan for drawing gas or into a separate component. The actuator can also act on the fan, in particular to increase or decrease the fan speed to control the gas supplied into the chamber. The fan can be configured to have a variable fan speed. In particular, the actuator can control the fan speed when at least one operating condition is not met. Alternatively, the actuator may be part of a gas valve or act on a gas valve. The control unit can control the flow cross-sectional area of ​​the gas valve and therefore the amount of gas supplied to the mixing chamber.

[0034] The first sensor can be located upstream or downstream of the actuator and / or gas valve. The first sensor can be located in the gas line through which gas is supplied to the mixing chamber. Alternatively, the first sensor can be located in a bypass line to the gas line. Placing the first sensor in a bypass line provides significantly more accurate measurements compared to placing it in the fuel gas line.

[0035] Furthermore, the gas heater may be equipped with an additional actuator for setting the fuel gas amount. The additional actuator may be integrated with the fuel gas valve or may be a separate component. The additional actuator may be configured to act on the fuel gas valve to control the fuel gas supplied to the mixing chamber. In particular, the additional actuator can control the fuel gas valve when additional operating conditions are not met. The control unit can control the additional actuator for setting the fuel gas amount when the additional operating conditions of the gas heater are not met. The additional operating conditions may include checking whether the determined fuel gas amount corresponds to a predetermined fuel gas amount. The determination of whether the additional operating conditions are met can be made after the determination of whether the operating conditions are met. In particular, the determination of the additional operating conditions is made only when the operating conditions are met.

[0036] If the heating process involves igniting a gas heater, particularly a burner, the control unit can control additional actuators based on a check to see if a fuel gas volume profile corresponds to a predetermined ignition lamp. The ignition lamp is a predetermined fuel gas profile that must be present to allow the burner to ignite. The additional actuator may be a fuel gas valve, or may act on a fuel gas valve. A second sensor may be located upstream or downstream of the additional actuator or fuel gas valve. The second sensor may be located in the fuel gas line, thereby supplying fuel gas to the mixing chamber. Alternatively, the second sensor may be located in a bypass line to the fuel gas line. Placing the second sensor in a bypass line provides significantly more accurate measurements compared to placing it in the fuel gas line.

[0037] Ignition lamps can be tested in a laboratory and adapted to gas and gas fuel settings to ensure correct ignition under all environmental conditions. In the laboratory, the ignition behavior of two burners is tested under extreme conditions. Cold system ignition occurs when the temperature is below 10°C, and hot system ignition occurs when the temperature exceeds 25 or 30°C. Furthermore, the burners can also be tested under climate chamber conditions where the temperature is below -40°C.

[0038] The ignition lamp can be judged based on these tests and ignition noise. The requirement is that ignition must occur without noise so that the air-to-gas ratio is adjusted to conform to a setting that guarantees noiseless ignition.

[0039] Furthermore, the length of the flue can also affect the ignition lamp. This is because longer flue leads to increased pressure loss, resulting in ignition being adjusted relative to the flue length. Additionally, the ignition lamp can be adjusted to minimize heat input.

[0040] The control unit can send a control signal to the actuator if the determined gas amount does not correspond to a predetermined gas amount. This occurs when the gas-to-fuel gas ratio of the gas mixture is not suitable for the intended operation of the burner, and the gas-to-fuel gas ratio of the gas mixture needs to be adjusted.

[0041] Based on the received control signal, the actuator increases or decreases the cross-sectional area of ​​the gas flow through the gas valve that supplies the gas to the mixing chamber. Finally, the gas volume can be easily controlled by the actuator.

[0042] The control unit may close the fuel gas valve if the determined fuel gas amount does not correspond to a predetermined fuel gas amount, particularly if the fuel gas amount profile does not correspond to a predetermined ignition lamp. This is necessary for security reasons. In particular, the presence of a mixture of explosive gases and fuel gases should be avoided. The fuel gas valve may be an electronically controlled gas valve.

[0043] The gas heater may be equipped with a third sensor for detecting a flame signal. The third sensor may be an optical sensor, such as a UV sensor, that can easily detect whether or not a flame is present, particularly a flame generated by burning a gas containing 95 mol% or more hydrogen. Alternatively, the third sensor may be a thermocouple, which can also detect the presence of a flame. The third sensor may be located in the burner. Alternatively, the third sensor may be located in the combustion chamber in which at least a portion of the burner is located.

[0044] The control unit can determine whether another operating condition is met. This can be done after the further operating condition has been met. This means that if the determined amount of fuel gas corresponds to a predetermined amount of fuel gas, flame signal detection can be performed. The other operating condition includes checking whether a flame signal is present. If no flame signal is detected, the fuel gas valve can be closed.

[0045] Furthermore, the gas heater may be equipped with temperature sensors for measuring the temperature in the combustion chamber and / or burner and / or the flue gas pipe of the gas heater. The control unit can determine whether additional operating conditions are met when other conditions are met. This means that the determination is made when a flame signal is detected. The control unit can check whether the measured temperature in the combustion chamber corresponds to a predetermined temperature, or whether the determined temperature rise in the combustion chamber exceeds a predetermined threshold. If this occurs, the additional operating conditions are met. Otherwise, the heating process is stopped or modified.

[0046] The gas volume can be determined after the fan begins supplying gas to the mixing chamber. The fuel gas volume can be determined after the fuel gas valve is opened. Therefore, it is not necessary to measure the gas volume and / or fuel gas volume all the time, but only when necessary.

[0047] Furthermore, the fuel gas quantity is determined after the gas quantity has been determined. The fuel gas quantity can be determined when the determined gas quantity corresponds to a predetermined gas quantity. Therefore, the risk of generating explosive mixtures can be reduced.

[0048] According to the embodiment, the fan speed can be used to check whether the gas heater is operating properly. In particular, the control unit may be adapted to check whether the fan speed corresponds to a predetermined fan speed assigned to a determined amount of gas, or whether it is within a predetermined fan speed range assigned to a determined amount of gas.

[0049] Such operation makes it easy to check whether the first sensor is functioning properly. In particular, considering the fan speed verifies the validity of the gas volume determination. If the first sensor is not functioning properly, the fan speed will not correspond to a given fan speed or will be outside the given fan speed range.

[0050] Therefore, for example, if the fan speed does not correspond to a predetermined fan speed during the ignition phase, or is outside the predetermined fan speed range, the boiler will shut down. The boiler will also shut down if the determined fuel gas does not correspond to a predetermined fuel gas quantity, in particular if the determined fuel gas profile does not correspond to a predetermined ignition lamp.

[0051] The heating process can be performed when the fan speed corresponds to a predetermined fan speed assigned to the determined amount of gas, or is within a predetermined fan speed range assigned to the determined amount of gas, and at least one condition is met. Otherwise, the heating process can be stopped.

[0052] In particular, the control unit may have at least one set gas flow rate with respect to differential pressure, in the form of a parameter curve that specifically refers to the heating process, for example, the ignition process. The gas flow rate may depend on the output of the boiler.

[0053] For the boiler, at least one parameter curve is stored in the control unit. The parameter curve shows that the gas flow rate is 0% to 100% of the mixture supplied to the burner, depending on the burner output. The set gas flow rate is predetermined, for example, in a laboratory. The differential pressure is associated with the expected fan speed in revolutions per minute (rpm). If the measured differential pressure and measured rpm are within a predetermined range, the heating process continues. Thus, the measurements are correlated with the pressure difference and rpm.

[0054] The control unit is also adapted to check whether the electrical signal supplied to the fuel gas valve corresponds to an electrical signal assigned to a predetermined fuel gas amount, or whether it is within a predetermined electrical signal range assigned to a predetermined fuel gas amount. This allows checking whether the second sensor is functioning properly and thus prevents situations, for example, where the amount of fuel gas supplied to the mixing chamber is much greater than the determined fuel gas amount. In particular, the validity of the determination of the fuel gas amount is verified by considering the electrical signals.

[0055] The heating process can be performed when the electrical signal supplied to the fuel gas valve corresponds to an electrical signal assigned to a predetermined amount of fuel gas, or is within a predetermined electrical signal range assigned to a predetermined amount of fuel gas, and at least one condition is met. Otherwise, the heating process can be terminated.

[0056] The control unit may have at least one set fuel gas flow rate, particularly in the form of a parameter curve, with respect to the differential pressure representing the heating process, such as the ignition process. The set fuel gas flow rate is predetermined, for example, in a laboratory. The fuel gas flow rate may depend on the boiler output. For the boiler, at least one parameter curve is stored in the control unit. The parameter curve represents the fuel gas flow rate, which is 0% to 100% of the mixture supplied to the burner, depending on the burner output. The differential pressure is associated with the expected electrical signal supplied to the fuel gas valve. If the measured differential pressure and the measured electrical signal are within a predetermined range, the heating process continues. Thus, the measured delta pressure and electrical signal are linked and matched.

[0057] In both cases, the sensor signals are used to verify that the system is functioning correctly.

[0058] According to embodiments of the present invention, the first sensor may be a flow sensor, particularly a mass flow sensor, and / or the second sensor may be a flow sensor, particularly a mass flow sensor. Each flow sensor, particularly a mass flow sensor, measures a differential pressure. The gas amount and fuel gas amount are determined based on the measured differential pressure, respectively. Therefore, the control unit can check whether the measured differential pressure corresponds to a predetermined differential pressure by determining whether the operating conditions and / or further operating conditions are met. Alternatively, the first sensor may be a volumetric flow sensor, and / or the second sensor may be a volumetric flow sensor.

[0059] In this embodiment, the gas heater is configured to use a gaseous fuel containing 10 mol% to 100 mol%, particularly 50 mol% to 100 mol%, preferably 95 mol% to 100 mol%, and more preferably 95 mol% to 98 mol% of hydrogen. The gas heater according to the present invention is not limited to the use of a gaseous fuel containing hydrogen. Any type of fuel gas, such as natural gas, methane, ethylene, propane, butane, coal gas, biogas, etc., mixtures thereof, and mixtures thereof further containing hydrogen, or hydrogen, particularly pure (at least 98 mol%) hydrogen, can be used as fuel. In this embodiment, the gaseous fuel also contains hydrogen, preferably 95 mol% or more. However, any combination of hydrogen and, for example, natural gas can be used.

[0060] A gas heater can be used in, or may be, a boiler. The boiler comprises a combustion chamber and a heat exchanger that can transfer heat generated by the burner of the gas heater to water. The burner of the gas heater is located at least partially inside the combustion chamber. The boiler may also be a condensing boiler. A condensing boiler achieves high energy efficiency by condensing the steam from the exhaust gas to recover the latent heat of vaporization. This has the additional advantage that condensing boilers use less fuel and electricity while emitting less CO2 compared to non-condensing boilers.

[0061] Boilers and / or gas heaters may have means of communication for communicating with communication devices, particularly servers. Communication can be established via data lines or wirelessly. Boilers and / or gas heaters can be configured for remote control. Control is possible, for example, by an application installed on a mobile device or computer. This simplifies the control and / or maintenance of boilers and / or gas heaters.

[0062] According to an advantageous embodiment, a heating system is provided. The heating system may comprise a fuel cell and / or a heat pump, preferably a gas absorption heat pump, and / or at least one photovoltaic (PV) module. The PV module can be used, for example, to heat a fluid being recirculated in the heat pump circuit.

[0063] Furthermore, an advantageous embodiment is a computer program product that, when the program is executed by the control unit, includes instructions causing the control unit to perform the method of the present invention. Additionally, a data carrier is provided in which the computer program is stored, and / or a data carrier signal is supplied for transmitting the computer program.

[0064] The diagram schematically illustrates the subject matter of the present invention, and elements that are identical or function similarly are usually given the same reference numerals. [Brief explanation of the drawing]

[0065] [Figure 1] This is a schematic diagram of a gas heater. [Figure 2] Figure 1 is a schematic diagram of a part of the gas heater shown. [Figure 3] This is a flowchart for the ignition process of a gas heater. [Modes for carrying out the invention]

[0066] The gas heater 1 shown in Figure 1 includes a mixing chamber 2 where gas and fuel gas are mixed. The mixed gas exits the mixing chamber 2 and is supplied to the burner 12 of the gas heater 1. Furthermore, the gas heater 1 includes a fan 13 located upstream of the mixing chamber 2 and used to draw in gas, especially ambient air. The first sensor 7 is located upstream of the fan 13 and is used to determine the amount of gas. However, the first sensor 7 can also be located downstream of the fan 13 (not shown). In this case, the first sensor 7 detects the amount of gas before it flows into the mixing chamber 2.

[0067] The gas heater 1 is equipped with a fuel gas valve 6. The fuel gas valve 6 controls the flow of fuel gas into the mixing chamber 2. A second sensor 8 is located downstream of the fuel gas valve 6 and upstream of the mixing chamber 2. The second sensor 8 determines the amount of fuel gas before it flows into the mixing chamber 2. The fuel gas is stored in a fuel gas tank (not shown).

[0068] The gas heater 1 also includes a control unit 9 as shown in Figure 2. The control unit 9 is adapted to determine whether at least one operating condition of the gas heater 1 is met based on the determined gas amount and / or determined fuel gas amount.

[0069] The gas heater 1 includes a manifold 14 located downstream of the mixing chamber 2 and upstream of the burner 12. The manifold 14 is used to supply the mixed gas to the burner 12. Although not shown in detail, part of the burner 12 is located in the combustion chamber 5. The combustion chamber 5 may be part of a boiler, which also includes a heat exchanger (not shown). The exchanged heat is used to exchange heat between the combustion chamber and water to heat the water. The flue gas exits the combustion chamber 5 as indicated by the arrow.

[0070] The gas heater 1 is equipped with an ignition electrode 15 used to ignite the burner 12. Specifically, the mixed gas supplied to the burner 12 is ignited. After ignition, the burner 12 heats the combustion chamber 5.

[0071] A third sensor 16 of the gas heater 1, particularly a detector, is used to detect the flame of the burner. Specifically, the third sensor 16 detects the presence or absence of a flame. A temperature sensor 17 of the gas heater 1 is used to measure the temperature which can be placed in the burner and / or combustion chamber 5, with the burner being preferred. Furthermore, the gas heater 1 may be equipped with a fourth sensor to measure one or more properties of a gas mixture (not shown). The composition of the gas mixture can be determined based on the sensor signal supplied by the fourth sensor.

[0072] Figure 2 shows a schematic diagram of a portion of the gas heater 1 shown in Figure 1. In particular, Figure 2 shows the portion of the gas heater 1 of Figure 1 located within a dotted rectangle. In this, the first and second sensors 7 and 8 are shown simply to illustrate that they are electrically connected to the control unit 9. The locations of the first and second sensors 7 and 8 are shown in Figure 1. As is clear from Figure 2, the gas heater 1 comprises an actuator 3 and a further actuator 4. The actuator 3 is used to control the fan 3, in particular the fan speed, to set the amount of gas in the gas line 19.

[0073] The actuator 3 and the fan 13 are two separate components positioned at a distance from each other. In another embodiment (not shown), the actuator 3 can be integrated with the fan 13. A further actuator 4 and the fuel gas valve 6 are two separate components positioned at a distance from each other. In another embodiment (not shown), the further actuator 4 can be incorporated into the fuel gas valve 6.

[0074] One end of the gas line 19 is fluidly connected to the mixing chamber 2. At the other end, the gas line 19 is fluidly connected to the fan 13 shown in Figure 1. A further actuator 4 is used to control the fluid gas valve 6 to set the amount of fuel gas in the fuel gas line 20. The fuel gas line 20 is fluidly connected to the mixing chamber 2 at one end. At the other end, the fuel gas line 20 is fluidly connected to a fuel gas tank (not shown).

[0075] The first sensor 7 is located upstream of the fan 13, as shown in Figure 1, and the second sensor 8 is located downstream of the fuel gas valve 6. Both sensors 7 and 8 are located upstream of the mixing chamber 2. In alternative embodiments not shown, sensor 7 may be located downstream of the fan 13. As can be seen from Figure 2, both sensors 7 and 8 and both actuators 3 and 4 are electrically connected to the control unit 9, as indicated by the dotted lines. The control unit 9 determines whether at least one condition, in particular several conditions, is met based on the determined gas amount and the determined fuel gas. Based on the determination result, the control unit 9 controls actuator 3 and the other actuator 4, as indicated by the dotted lines.

[0076] Figure 3 shows a flowchart of the heating process of the gas heater 1. In this case, the heating process is the ignition process. However, the operation of the gas heater 1 according to the method of the present invention is not limited to the ignition process of the burner 12.

[0077] In the first step S1, the heating process is started. As a result, the control unit 9 receives a heating request. Subsequently, in the second step S2, the control unit 9 performs sensor signal control, and in the third step S3, it verifies whether the sensor is operating and / or in operating mode. If the verification is unsuccessful, the heating process is terminated.

[0078] If the verification in the third step S3 is successful, the fan 13 is started in the fourth step S4. After the fan is started, in the fifth step S5, the first sensor 7 starts determining the amount of gas and transmits the sensor signal to the control unit 9. In the sixth step S6, the control unit 9 checks whether the operating conditions for the gas heater 1 are met. In particular, the control unit 9 checks whether the determined amount of gas corresponds to a predetermined amount of gas. This allows the control unit 9 to check whether the measured differential pressure corresponds to a predetermined differential pressure. The predetermined gas quality depends on the power that the burner 12 must supply.

[0079] If the determined gas amount does not correspond to a predetermined gas amount, the control unit 9 sends a control signal to the actuator 3, and steps S5 and S6 are repeated. The mixing chamber 2 can be back-ventilated before the control signal is sent to the actuator 3. If, after a predetermined number of trials, the determined gas amount does not correspond to a predetermined gas amount, the heating process is terminated.

[0080] However, if the control unit 9 determines in the sixth step S6 that the determined gas amount corresponds to a predetermined gas amount, then in the seventh step S7, the ignition electrode 15 sparks. Subsequently, in the eighth step S8, the fuel gas valve opens and the second sensor 8 begins to determine the fuel gas amount.

[0081] In the ninth step S9, the control unit 9 determines whether further operating conditions are met. In particular, the control unit 9 checks whether the determined fuel gas amount corresponds to a predetermined fuel gas amount. Specifically, the control unit 9 checks whether the determined ignition lamp corresponds to a predetermined ignition lamp. In this case, the heating process continues in the tenth step S10.

[0082] In the tenth step S10, the control unit 9 determines whether other operating conditions are met. In particular, the control unit 9 determines whether there is a flame. If the third sensor 16 detects the presence of a flame, in the eleventh step S11, the temperate sensor 17 measures the temperature of the combustion chamber 5. Also in the eleventh step S11, the control unit 9 determines whether additional operating conditions are met. In particular, the control unit 9 checks whether the measured temperature exceeds a threshold. In this case, the heating process is successfully completed.

[0083] In the ninth step S9, if the control unit 9 determines that the determined fuel gas amount does not correspond to a predetermined fuel gas amount and / or the measured ignition lamp does not correspond to a predetermined ignition lamp, the fuel gas valve 6 is closed. Similarly, in the tenth step S10, if no flame is detected by the third sensor 16, the fuel gas valve 6 is closed. In either case, the mixing chamber 2 is back-ventilated and processing steps S7 to S10 are repeated. However, as described above for processing steps S5 and S6, processing steps S7 to S10 are repeated only for a predetermined number of trials. If the aforementioned further conditions, other conditions and additional conditions are not met within the predetermined number of trials, the heating process is terminated.

[0084] In the 11th step S11, if the control unit 9 determines that the temperature is below a threshold, it stops the heating process. [Explanation of symbols]

[0085] 1. Gas heater 2 Mixing chamber 3 Actuators 4. Further actuators 5 Combustion chamber 6. Fuel gas valve 7. First Recovery 8. Second Sensor 9. Control Unit 12 burners 13 Fans 14 Manifold 15 Ignition electrode 16. Third Sensor 17 Temperature sensor 19 Gas lines 20 Fuel gas line S1-S11 Steps 1 through 11

Claims

1. A method for operating a gas heater (1) selected from a gas boiler or a condenser boiler for supplying central heating and / or hot water to a household, The steps of supplying a fuel gas containing gas and 95 mol% to 100 mol% hydrogen into the mixing chamber (2) of the gas heater (1), and supplying the mixed gas from the mixing chamber (2) to the burner (12) of the gas heater (1), Before the gas is supplied to the mixing chamber (2), the steps include measuring the differential pressure and / or providing a sensor signal to the control unit in order to determine the amount of gas determined by volume per unit time or mass per unit time, Before the fuel gas is supplied to the mixing chamber (2), the steps include measuring the differential pressure and / or presenting the sensor signal to the control unit in order to determine the amount of fuel gas determined by volume per unit time or mass per unit time, A step of determining whether one operating condition of the gas heater (1) is met based on the determined amount of gas, wherein the operating condition includes checking whether the determined amount of gas corresponds to a predetermined amount of gas. A step of determining whether further operating conditions for the gas heater (1) are met based on the determined amount of fuel gas, wherein the further operating conditions include checking whether the determined amount of fuel gas corresponds to a predetermined amount of fuel gas. A method comprising the following: the determination of the further operating conditions is performed when the operating conditions are met, and the ignition electrode (15) sparks when the determined amount of gas corresponds to a predetermined amount of gas.

2. a. The actuator (3) for setting the gas amount is controlled when the one operating condition is not met, and / or b. The actuator (3) for setting the gas amount is controlled based on a check to see whether the determined gas amount corresponds to a predetermined gas amount, and / or c. The method according to claim 1, characterized in that the actuator (3) controls the speed of the fan to control the gas supplied into the chamber of the gas heater (1) when the one operating condition is not met.

3. The method according to claim 2, characterized in that when the determined amount of gas does not correspond to the predetermined amount of gas, a control signal is transmitted to the actuator (3).

4. a. The additional actuator (4) for setting the amount of fuel gas is controlled when the additional operating conditions are not met, and / or b. The further actuator (4) for setting the fuel gas amount is controlled based on a check of whether the determined fuel gas amount corresponds to a predetermined fuel gas amount, in particular whether the fuel gas amount profile corresponds to a predetermined ignition lamp, and / or c. The method according to any one of claims 1 to 3, characterized in that a further actuator (4) controls the fuel gas valve (6) when further operating conditions are not met.

5. a. It is determined whether another operating condition is met, and the other operating condition includes the check for the presence of a flame signal, and / or b. The method according to any one of claims 1 to 4, characterized in that when the determined amount of fuel gas corresponds to a predetermined amount of fuel gas, it is determined whether or not another operating condition is met.

6. The fuel gas valve (6) a. When the determined fuel gas amount does not correspond to a predetermined fuel gas amount, in particular when the fuel gas amount profile does not correspond to a predetermined ignition lamp, and / or b. If no flame signal is detected The method according to claim 4 or 5, characterized in that it is closed.

7. a. The additional operating conditions include a check to determine whether the additional operating conditions are met, and whether the measured temperature of the combustion chamber (5) of the gas heater (1) or the determined temperature rise of the combustion chamber (5) exceeds a predetermined threshold, and / or b. The amount of gas is determined after the fan (13) begins supplying gas to the mixing chamber (2), and / or c. The amount of fuel gas is determined after the fuel gas valve (6) is opened, and / or d. The amount of fuel gas is determined after the amount of gas has been determined, and / or e. The method according to any one of claims 1 to 6, characterized in that the amount of fuel gas is determined when the determined amount of gas corresponds to a predetermined amount of gas.

8. a. It is checked whether the fan speed corresponds to a predetermined fan speed assigned to the determined amount of gas, or whether it is within the range of predetermined fan speeds assigned to the determined amount of gas, and / or, b. The method according to any one of claims 1 to 7, characterized in that it is checked whether the electrical signal presented to the fuel gas valve (6) corresponds to the electrical signal assigned to the predetermined amount of fuel gas, or whether it is within the range of the predetermined electrical signals assigned to the predetermined amount of fuel gas.

9. a. The heating process is performed when the speed of the fan corresponds to a predetermined fan speed assigned to the determined amount of gas, or is within the range of predetermined fan speeds assigned to the determined amount of gas, and / or when at least one condition is met. b. The method according to claim 8, characterized in that the heating process is performed when the electrical signal presented to the fuel gas valve (6) corresponds to an electrical signal assigned to the predetermined amount of fuel gas, or is within the range of a predetermined electrical signal assigned to the predetermined amount of fuel gas, and at least one of the above conditions is met.

10. A gas heater (1), A mixing chamber (2) for mixing gas and a fuel gas containing 95 mol% to 100 mol% hydrogen; a burner (12) located downstream of the mixing chamber (2) and capable of supplying the mixed gas from the mixing chamber (2); an ignition electrode (15) for igniting the burner (12); a first sensor (7) for displaying a sensor signal to a control unit for measuring differential pressure and / or for determining the amount of gas determined by the volume or mass per unit time of the gas supplied to the mixing chamber; and a second sensor for displaying a sensor signal to a control unit for measuring differential pressure and / or for determining the amount of fuel gas determined by the volume or mass per unit time of the fuel gas supplied to the mixing chamber (2). A gas heater (1) comprising: two sensors (8); and a control unit (9) adapted to determine whether one operating condition of the gas heater (1) is met based on the determined amount of gas, wherein the operating condition includes checking whether the determined amount of gas corresponds to a predetermined amount of gas; and adapted to determine whether a further operating condition of the gas heater (1) is met based on the determined amount of fuel gas, wherein the further operating condition includes checking whether the determined amount of fuel gas corresponds to a predetermined amount of fuel gas, the determination of the further operating condition is performed when the operating condition is met, and the ignition electrode (15) is sparked when the determined amount of gas corresponds to a predetermined amount of gas.

11. a. The gas heater (1) is equipped with a temperature sensor (17) for measuring the temperature of the combustion chamber (5) and / or the burner (12), and / or b. The control unit (9) is configured to check whether the fan speed corresponds to a predetermined fan speed assigned to the determined gas amount, or whether it is within the range of predetermined fan speeds assigned to the determined gas amount, and / or c. The control unit (9) is configured to check whether the electrical signal presented to the fuel gas valve (6) corresponds to the electrical signal assigned to the predetermined fuel gas amount, or is within the range of the predetermined electrical signals assigned to the predetermined fuel gas amount, and / or d. The gas heater (1) according to claim 10, characterized in that the gas heater (2) is configured to use a fuel gas containing at least 10 mol%, and particularly at least 95 mol%, of hydrogen.

12. A boiler for heating a liquid, especially water, a condensing boiler, comprising a gas heater (2) as described in claim 11 and a heat exchanger having a combustion chamber, wherein the burner (12) of the gas heater (1) is at least partially located inside the combustion chamber.

13. A heating system comprising a gas heater according to claim 10 or 11 or a boiler according to claim 12, further comprising a fuel cell and / or a heat pump, preferably a gas absorption heat pump, and / or at least one photovoltaic (PV) module.

14. Use of the gas heater according to claim 10 or 11 or the boiler according to claim 12 for heating applications of hydrogen or hydrogen-containing fuel gas, or for heating applications of natural gas.

15. A computer program product comprising, when executed by a control unit, an instruction causing the control unit to perform the method according to any one of claims 1 to 9.

Images