A gas burner comprises an automatic firing unit for regulating or controlling an amount of gas supplied to the gas burner via a gas control valve and a lambda probe (1) arranged in the exhaust gas flow for measuring a residual oxygen content in the exhaust gas. A method for operating the gas burner comprises a first operating state in which the gas burner is operated in standard mode, wherein the residual oxygen content in the exhaust gas is regulated via the measured value of the lambda probe (1). According to the invention, in a second operating state, the gas burner performs a fault test on the lambda probe (1) involving the steps of: deactivating (S18) a supply of power to a pump cell (PZ) of the lambda probe (1); determining a present test voltage (h) of a measurement cell (NZ) of the lambda probe (1); comparing (S25) the present test voltage (h) with a predefined test setpoint voltage (i) and determining a difference; and if the difference exceeds a predefined limit value, performing a safety deactivation (S29); or if the difference does not exceed the predefined limit value, operating the gas burner in the first operating state.

A method for commissioning a gas valve assembly for controlling fuel flow to a combustion appliance. An example method for commissioning the gas valve assembly may include initiating a commissioning mode in the controller of the gas valve assembly. Once in the commissioning mode, inputting a user defined initial air to fuel (A/F) ratio, activating the combustion appliance, setting a burner load of the combustion appliance to a set burner load, inputting a desired A/F ratio for the set burner load, running the combustion appliance at the burner load with the desired A/F ratio, and observing the operation of the combustion appliance. The method may further include saving the desired A/F ratio for the set burner load to the controller of the gas valve assembly and exiting the commissioning mode.

A sensor for determining an air ratio of a fuel gas/air mixture, wherein a housing is formed, which delimitates a measuring space. The housing has on one side a diffusion passage for coupling with a fuel gas/air mixture flow, wherein the diffusion passage is formed by a gas-permeable separating agent. An electrically operated excitation element is arranged for energy supply into the measuring space in order to induce a chemical reaction of a fuel gas/air mixture in the measuring space. At least one optical detection device is directed into the measuring space with its detection area, wherein the at least one optical detection device detects the intensity of radiation from the reaction position in at least a first wavelength range and produces a signal being allocated to the detected intensity, from which the air ratio is inferable.

The present disclosure deals with the detection of a blockage in the air-supply duct or flue of a burner assembly. In some embodiments, a method or system may detect blockages in the form of coverings and with burner assemblies to burn fossil fuels. For example, a control device may generate: a first air-control signal; a fuel-control signal by adjusting the actual values of the ionization current to the ionization-current setpoint; a setpoint increased by a specified amount from the ionization-current setpoint; and a changed fuel-control signal by adjusting the actual values of the ionization current to the increased setpoint in the case of a first air-control signal. The control device may evaluate the changed fuel-control signal generated based on the increased setpoint by comparing it with a specified maximum value and based on the evaluation, to detect a blockage. The control device may recognize the blockage based on the evaluation if the fuel-control signal generated using the increased setpoint exceeds the specified maximum value.

A burner includes a flame sensor configured to detect at least one of permittivity, capacitance, or resistance across a flame region. The permittivity, capacitance, or resistance is used to determine the presence or absence of the flame in a combustion system. A combustion system supports a combustion reaction. The combustion system utilizes a combustion sensor, and optionally a plasma generator to stabilize the combustion reaction. A controller receives sensor signals from the combustion sensor and controls the plasma generator to stabilize the combustion reaction responsive to the sensor signals. The plasma generator stabilizes the combustion reaction by generating a plasma.

A system for measuring a fuel-oxidant equivalence ratio includes at least one wall defining a gas volume including fuel and air. A gas ionization source is configured to cause a formation of ions in the gas. A power supply is configured to output a time-varying voltage. A first electrode is disposed in the gas volume, operatively coupled to the power supply, and configured to carry the time-varying voltage. A second electrode is arranged to operatively couple to a signal output by the first electrode after the signal passes through the gas volume. Characteristics of the received signal indicate the fuel-oxidant equivalence ratio.

In a method for estimating water content of exhaust gas, a first gas concentration at a first position in an exhaust passage, a second gas concentration at a second position downstream of the first position, and a gas temperature at the second position are obtained. A saturated water vapor at the gas temperature is calculated as a water content at the second position. By using the water content at the second position and the second gas concentration, an excess air amount of a fuel-air mixture supplied to a combustion apparatus is calculated based on a chemical reaction formula of combustion of the mixture. By using the excess air amount and the first gas concentration, a water content at the first position is estimated.

A system includes a probe disposed through one or more walls of a turbomachine. The probe includes a sensing component configured to sense a parameter of the turbomachine. The probe also includes a body coupled to the sensing component, an inlet configured to receive a cooling inflow, a shell that defines a cooling passage, and an outlet. The sensing component is disposed on a warm side of the one or more walls. The inlet and the outlet are disposed on a cool side of the one or more walls. The cooling passage directs the cooling inflow toward the sensing component and toward the outlet. The outlet is configured to receive an outflow from the cooling passage, wherein the outflow includes at least a portion of the cooling inflow.

In a method for estimating water content of exhaust gas, a first gas concentration at a first position in an exhaust passage, a second gas concentration at a second position downstream of the first position, and a gas temperature at the second position are obtained. A saturated water vapor at the gas temperature is calculated as a water content at the second position. By using the water content at the second position and the second gas concentration, an excess air amount of a fuel-air mixture supplied to a combustion apparatus is calculated based on a chemical reaction formula of combustion of the mixture. By using the excess air amount and the first gas concentration, a water content at the first position is estimated.

A sensor for determining an air ratio of a fuel gas/air mixture, wherein a housing is formed, which delimitates a measuring space. The housing has on one side a diffusion passage for coupling with a fuel gas/air mixture flow, wherein the diffusion passage is formed by a gas-permeable separating agent. An electrically operated excitation element is arranged for energy supply into the measuring space in order to induce a chemical reaction of a fuel gas/air mixture in the measuring space. At least one optical detection device is directed into the measuring space with its detection area, wherein the at least one optical detection device detects the intensity of radiation from the reaction position in at least a first wavelength range and produces a signal being allocated to the detected intensity, from which the air ratio is inferable.