A method is provided for heating a furnace arranged with a heating zone heated with a burner providing a flame extending in a longitudinal direction and fed with a fuel and a primary oxidant, the burner is operated with a mass relationship between the fed fuel and primary oxidant permitting less than 50% of the fed fuel to be combusted using the primary oxidant, and a respective pair of secondary oxidant lances are provided one either side of the furnace pointing into the heating zone, lancing a secondary oxidant into the heating zone downstream of the burner substantially parallel with a cross plane, such that a temperature is measured downstream of the lances and that each of the lance pairs includes an upstream, low-speed first and a downstream, high-speed second lance, wherein the amount of secondary oxidant supplied via the first lance is regulated to achieve a homogenous lateral temperature profile. A related furnace is also provided.

The present invention relates to a method of controlling a gas furnace that performs heating operation according to a heating signal formed of one of a weak heating signal and a strong heating signal. The method includes: (a) receiving the heating signal; (b) determining whether the heating signal is the weak heating signal or the strong heating signal; (c) calculating a certain weak heating capacity smaller than a maximum heating capacity of the gas furnace, when the heating signal is the weak heating signal; and (d) operating a weak heating of the gas furnace with the calculated certain weak heating capacity, wherein the step (c) includes calculating the weak heating capacity according to a difference between a temperature of air (hereinafter, an intake air temperature) sucked into the gas furnace and a reference temperature set based on the intake air temperature.

A burner control valve with speed control includes a speed control assembly for metering loading pressure into a loading pressure chamber to prevent pilot light blow out and/or backfire in a downstream burner.

A gas burner assembly and a method of operating the same are provided. The gas burner assembly includes an air pump that supplies a flow of air into a boost fuel chamber for mixing with a flow of boost fuel before being combusted and directed through a plurality of boost flame ports. A temperature sensor is positioned proximate the air pump and a controller regulates the power supplied to the air pump to compensate for air pump operating characteristics based on the measured temperature. A pressure sensor may also detect a low pressure condition downstream of the air pump and shut down the fuel and air supply system accordingly.

A system for automatically shutting off gas flow to a furnace may include an inlet for supplying a gas to the furnace. The furnace may have a housing. The system may include a thermometer positioned inside between the furnace and the housing. A resettable limit switch may be in electrical communication with the thermometer. An electric shutoff valve may be positioned inline between the inlet and the furnace and in electrical communication with the resettable limit switch. A manual shutoff valve may be positioned inline between the inlet and the electric shutoff valve and may manually shut off gas flow to the furnace. When the thermometer reaches a predetermined temperature, the resettable limit switch may actuate the electric shutoff valve thereby shutting off flow of the gas to the furnace. The electric shutoff valve may only be re-opened by manually resetting the resettable limit switch.

Apparatus and methods for a gas furnace are disclosed. The gas furnace includes a variable combustion control which monitors the temperature of the burner and modifies one of the amount of combustion air supplied and the amount of gas fuel supplied to the mixing chamber. The described systems can dynamically accommodate differences in air quality and gas fuel supply to provide an optimum BTU output irrespective of differences in geographic location of usage. The gas furnace can include a dynamic response unit which predicts an optimum rate of heating to maintain a target room temperature, thereby preventing unnecessary shut down and costly re-ignition sequences, and maintaining the gas furnace at an optimum BTU output level.

A gas appliance includes a burner, a gas valve, and a control device, wherein the gas valve includes a valve body, a flow regulator, a hot film anemometer, and a stepper motor. The valve body communicates with the burner and a gas source. The flow regulator is driven by the stepper motor to change a gas flow rate supplying to the burner. The hot film anemometer is disposed in the valve body and includes a probe exposed to the outlet passage. The control device executes a control method for the gas valve: sensing the gas flow rate in the outlet passage with the hot film anemometer; comparing the gas flow rate sensed by the hot film anemometer with a predetermined gas flow rate, and controlling the stepper motor to drive the flow regulator based on the comparison result, whereby to stabilize the gas flow rate.

A plurality of water heaters are connected in parallel with respect to a hot water supply path, and each of the plurality of water heaters has an exhaust path connected to an exhaust path assembly. Each of a plurality of sensing units is configured to be shifted from an electrically conducting state to an electrically non-conducting state when each of the plurality of sensing units senses an abnormal condition about air supply or exhaust. A series circuit of the plurality of sensing units is electrically connected in series to a resistance element between the power supply line and the ground line. The controller is configured to monitor an abnormal condition about air supply or exhaust based on a voltage on a node between the series circuit and the resistance element.

A heat controlled oven system includes a plurality of oven levels, including an oven belt and gas burners; a gas flow network, including a gas supply line, a variable flow control valve, and on/off flow control valves; and a heat control unit, including a processor, a non-transitory memory, and input/output component, a heat modeler, a heat manager, a feedback controller, and a valve controller, such that the heat control unit is configured to calculate an estimated heat demand to adjust to a temperature set point, based on a heat model of the at least one oven level, and further calculates an optimized heat demand using a control loop feedback algorithm. Also disclosed is a method of heat calculation for an oven, including defining a heat model, calculating and optimizing the estimated heat demand, calculating and setting a variable valve position for the gas burners.

A heat controlled oven system includes a plurality of oven levels, including an oven belt and gas burners; a gas flow network, including a gas supply line, a variable flow control valve, and on/off flow control valves; and a heat control unit, including a processor, a non-transitory memory, and input/output component, a heat modeler, a heat manager, a feedback controller, and a valve controller, such that the heat control unit is configured to calculate an estimated heat demand to adjust to a temperature set point, based on a heat model of the at least one oven level, and further calculates an optimized heat demand using a control loop feedback algorithm. Also disclosed is a method of heat calculation for an oven, including defining a heat model, calculating and optimizing the estimated heat demand, calculating and setting a variable valve position for the gas burners.