Cooktop appliances are provided. A cooktop appliance can include a gas burner; a manifold having a gas input; a primary line extending between the manifold and the gas burner, wherein the primary line operates as a non-modulated minimum gas flow line when the cooktop appliance is in an automatic mode; a secondary line extending between the manifold and the gas burner, wherein a gas flow rate of the secondary line is controllable by a flow control valve; a primary valve in fluid communication with at least the primary line; and a control system including: a sensor configured to detect a temperature corresponding to the gas burner; and a controller regulating: (i) the flow control valve in response to the detected temperature to achieve a desired temperature, and (ii) the primary valve when the flow control valve is closed and the detected temperature exceeds the desired temperature.

A method, control unit and rotating machine for determining a fuel split setting value for adjusting a fuel split setting for a combustion device, the fuel split setting defining a relation between main fuel and pilot fuel. The method includes: retrieving a first information item correlated to heating value of supplied main fuel; retrieving a second information item correlated to combustor operating condition; retrieving at least one third information item representing stability of combustion; selecting a predefined pair of minimum and maximum boundary curves for the fuel split setting from a plurality of predefined pairs based on the first and second information items, the minimum and maximum boundary curves defining a band of fuel split settings permitted for a range of second information item values; determining the fuel split setting value within the selected pair of minimum and maximum boundary curves based on the third information item.

According to an embodiment, a fired heater includes a fuel and combustion air source configured to output fuel and combustion air into a combustion volume, the combustion volume including a combustion volume wall defining a lateral extent separate from an exterior volume. According to an embodiment, the fired heater includes a boiler heater and the combustion volume wall comprises a combustion pipe defining a lateral extent of the combustion volume, the combustion pipe being disposed to separate the combustion volume from a water and steam volume. The fired heater includes a mixing tube aligned to receive the fuel and combustion air from the fuel and combustion air source. The mixing tube may be separated from the combustion volume wall by a separation volume. The fired heater includes a bluff body flame holder aligned to receive a fuel and combustion air mixture from an outlet end of the mixing tube. The bluff body flame holder may be configured to hold a combustion reaction for heating a combustion volume wall. The combustion volume wall may include a combustion pipe. The combustion pipe may be configured to heat the water in the water and steam volume.

An ammonia combustion method for combusting ammonia gas in a combustion chamber 4 includes steps of separating and producing hydrogen gas from ammonia gas, supplying the separated and produced hydrogen gas into the combustion chamber 4, combusting the hydrogen gas by performing an ignition discharge on the hydrogen gas supplied into the combustion chamber 4, and igniting the ammonia gas in the combustion chamber 4 from the combusted hydrogen gas.

An ammonia combustion method for combusting ammonia gas in a combustion chamber 4 includes steps of separating and producing hydrogen gas from ammonia gas, supplying the separated and produced hydrogen gas into the combustion chamber 4, combusting the hydrogen gas by performing an ignition discharge on the hydrogen gas supplied into the combustion chamber 4, and igniting the ammonia gas in the combustion chamber 4 from the combusted hydrogen gas.

A cooktop appliance includes a first burner and a second burner which are spaced apart with a grate positioned above the burners. The grate includes a first sensor finger with a first temperature sensor over the first burner and a second sensor finger with a second temperature sensor over the second burner. The cooktop appliance also includes a first control valve and a second control valve which selectively direct fuel to the respective burners. A controller of the cooktop appliance is operably coupled to the temperature sensors and the control valves. The controller may be operable for and/or methods of operating the cooktop appliance may include receiving a set temperature, receiving a first temperature measurement from the first temperature sensor and a second temperature measurement from the second temperature sensor, and adjusting each control valve based on the set temperature and the corresponding temperature measurement.

A cooking appliance including an oven compartment, and first and second gas burners positioned to supply heat to the oven compartment. The first and second gas burners respectively include first and second electromechanical modulating valves that respectively couple the first and second gas burners to a gas supply. A controller is used to control the first and second gas burners to heat the oven compartment, and the controller, when maintaining a predetermined temperature in the oven compartment, controls the electromechanical modulating valves of the first and second gas burners to vary respective output levels of the first and second gas burners while maintaining a substantially constant combined output level for the first and second gas burners.

A flame sensing system, a flame sensing unit, and a method for sensing a flame are described. The flame sensing system includes a flame sense probe and a power regulating device. The power regulating device is configured to generate a regulated voltage from an input voltage received from a power source and to output the regulated voltage to the flame sense probe such that a flame current along a flame can be measured. The flame sensing system also includes a flame current detector to measure the flame current and generate an output voltage corresponding to the flame current, and a first level detector to generate a flame strength output signal based on the output voltage, where the flame strength output signal is indicative of a strength of a flame.

A water heater may include a water tank, a burner, a pilot for igniting the burner, an ignitor for igniting the pilot, a thermoelectric device in thermal communication with a flame of the pilot, a controller for controlling an ignition sequence of the pilot using the ignitor, and a rechargeable power storage device for supplying power to the ignitor and the controller. The rechargeable power storage device may be rechargeable using the energy produced by the thermoelectric device. The controller is configured to selectively run only the pilot for at least part of a heating cycle to increase the recharge time of the rechargeable power storage device while still heating the water in the water heater.

A furnace includes a perforated flame holder formed from an array of tiles. The perforated flame holder is stabilized by a support member extending between at least adjacent tiles. Elongated support members may be positioned to extend through each of the tiles in a respective column of the array of tiles.