A method for lowering emissions that result from fuel combustion in a boiler may include obtaining a fuel composition, an air composition, and ambient conditions; determining, based on the fuel composition, the air composition, and the ambient conditions, a temperature margin sufficient for reliable combustion, and a minimum adiabatic flame temperature (AFT_LFL) for sustainable combustion within the boiler; establishing a combustion temperature control envelope bounded by the minimum AFT_LFL plus the temperature margin sufficient for reliable combustion, and by a threshold temperature below which thermal NOx formation is minimized; controlling, via a feedforward cascade control algorithm, an injection rate of the fuel into the boiler via a fuel injection system and an injection rate of air into the boiler via an air injection system; and automatically adapting the feedforward cascade control algorithm and associated control setpoints to remain within the combustion temperature control envelope.

A motor controller for a draft inducer motor that operates an inducer blower in a furnace is provided. The motor controller includes a communication interface operable to receive a signal from a system controller. The signal represents a command to operate the draft inducer motor. The motor controller includes a processor operable to operate the draft inducer motor in accordance with a predefined motor speed profile during at least one of an ignition stage and a combustion stage of the furnace.

Various embodiments include a method for regulating a burner appliance comprising a combustion chamber, an air supply duct with an actuator to adjust the air supply, and a fuel supply duct with a fuel actuator to adjust the fuel supply. The method comprises: determining the value of the air supply V L; determining the value of an air ratio ; providing an individual scalar fuel parameter h; calculating the power output P_ist of the appliance based on the air supply V L, the air ratio , and the individual scalar fuel parameter h using P_ist=h/.Math.V L; and regulating the burner appliance with the fuel actuator and the air actuator until the actual value reaches the target value.

A combustion device includes a fan; a premixing device capable of generating an air-fuel mixture by driving the fan; and an ignition device capable of ignition operation for the air-fuel mixture in a combustion chamber. The premixing device includes a flapper capable of opening and closing a part of a gas flow path and has a larger opening degree when the drive speed of the fan is high speed than low speed. The ignition operation for the air-fuel mixture by the ignition device is a standard ignition operation in principle, executed in a first drive speed range of the fan in which the flapper is in an open state, and exceptionally a non-standard ignition operation, executed in a second drive speed range of the fan in which the flapper is in a closed state in the case where the air-fuel mixture is not ignited by the standard ignition operation.

An electronic control device includes: a flow rate calculation unit that calculates a flow rate of intake air based on an output signal of a flow rate measurement device assembled to an intake pipe; a flow rate correction value calculation unit that calculates an average value, a maximum value, and a minimum value of the flow rate of the intake air, calculated by the flow rate calculation unit, during a predetermined period, and an amplitude of a signal with one or more frequencies equal to or higher than a fundamental frequency of the output signal of the flow rate measurement device and included in the output signal of the flow rate measurement device, and calculates a correction value for the flow rate of the intake air based on calculation results; and a flow rate correction unit that corrects the flow rate of the intake air based on the correction value.

A device for controlling a fuel-oxidizer mixture for a premix gas burner includes: an intake duct, including an inlet, a mixing zone, and a delivery outlet; an injection duct; a gas regulating valve, located along the injection duct; a fan, located in the intake duct to generate therein a flow of the oxidizer fluid or of the mixture; a control unit, configured for generating drive signals; a sensor unit, configured to detect a first differential pressure, between a first detecting section, located in the intake duct upstream of the mixing zone in the direction of inflow and a second detecting section, located in the intake duct downstream of the mixing zone in the direction of inflow, and configured to detect a second differential pressure, between the first detecting section and a third detecting section, located in the injection duct between the gas regulating valve and the mixing zone.

A system and method for optimizing combustion in boiler. The optimization of the combustion in the boiler involves obtaining various data relating to the flow of fuel and air to burners of the boiler and the flame in the burner zone of the boiler that is generated from the introduction of the fuel and air into the burner zone. The data is used to determine air flows to the burners. The data and air flows are used to balance air and fuel at individual burners by manipulating air to match the fuel flow. The balancing of air and fuel at individual burners by manipulating air to match the fuel flow uses a guided search optimization algorithm that mixes stoichiometry determinations with a custom search algorithm that accounts for measurement inaccuracies and unexpected interactions between burners.

Method for operating a gas burner appliance (10) comprising: a combustion chamber (11), an ignition device (27), a fan (14), a gas safety valve unit (19) assigned to the gas duct (16), an electric gas flow modulator (18) assigned to the gas duct (16), a sensor (21) positioned between the gas safety valve unit (19) and the gas flow modulator (18), wherein the gas burner appliance (10) is operated to determine the gas family of the gas of the gas/air mixture by the following steps: Before the gas burner appliance becomes started measuring the ambient air pressure by the sensor (21), wherein the ambient air pressure is measured when the safety valve unit (19) is closed, the gas flow modulator (18) is opened and the fan (14) is stopped. When the gas burner appliance (10) becomes started running the fan (14) at a defined fan speed, increasing the opening of the gas flow modulator (18) while activating the ignition device (27) trying to ignite the gas/air mixture until the activation of ignition device results into a combustion of the gas/air mixture. Determining from the fan speed of the fan (14) and from the measured ambient air pressure an air volume flow. Measuring the gas pressure by the sensor (21) when the safety valve unit (19) is opened, the gas flow modulator (18) is opened and the fan (14) is running. Determining from the opening of the gas flow modulator (18) at which the combustion started and from the measured gas pressure a gas volume flow. Determining a ratio between the gas volume flow and the air volume and from said ratio the gas family of the combusted gas.