Control unit for detecting a flame in operation using flame monitors suitable for burners operated using a fuel, wherein the flame monitor comprises at least one sensor as operating means for detecting the radiation emission from a flame as a visible reaction between fuel and oxidizing oxygen in a combustion region, and an evaluation circuit associated with the at least one sensor, the evaluation circuit determining whether the radiation received by the sensor corresponds to that of a burning flame and, if the result is negative, generating a fuel supply switch-off signal, wherein at least two flame detectors are connected in such a way that a basic electrical circuit is formed which processes the output signals of the at least two flame monitors via closing contacts in an OR operation or via closing contacts in an AND operation, depending on which of at least two operating states of flame detection is assigned to the output signals of the flame monitors, and a switching logic is provided for switching between the at least two operating states, which logic links an intelligent subsystem with a logic function plan.

A horticultural smudging system and method for improving the growth and/or production of plants. Combustible material is burnt within a thermal container, and the resulting flue gas containing negative ions and carbon dioxide is propelled onto one or more plants. The smudging system and method may use one or more sensors to detect oxygen, air pressure, and flue gas levels within the thermal container to adjust air intake and the release of flue gas.

Methods and apparatus to indicate presence of a flame are disclosed. An example gas grill includes a burner tube having apertures to emit a fuel for combustion, an ignition element to cause ignition of the fuel emitted from the apertures of the burner tube, a flame sensor to detect the presence of a flame associated with the combustion of the fuel emitted from the apertures of the burner tube, and flame sense circuitry including a flame signal accessor to access a flame sense signal from the flame sensor, and a terminal to output an indication of the presence of the flame, the indication of the presence of the flame output without respect to an open or closed state of a lid of the grill.

Methods and related systems for operating a furnace are disclosed. In an embodiment, the method includes activating a burner assembly and a first fan of the furnace to combust fuel and air and circulate combustion gases along a flow path extending through a heat exchanger of the furnace. In addition, the method includes operating a second fan of the furnace to circulate air across an external surface of the heat exchanger of the furnace and produce a conditioned airflow. Further, the method includes monitoring one or more parameters of a motor of the second fan indicative of an airflow rate of the conditioned airflow, and deactivating the burner assembly, whereby combustion of the fuel and air in the furnace ceases, in response to the one or more parameters indicating that the airflow rate is less than a minimum airflow rate.

A fire pit comprises a fuel source connector and at least one fuel outlet. A fuel conduit conveys fuel from the fuel source connector to the fuel outlet, and there is at least one sensor for detecting the presence of unburned fuel outside the fuel conduit. Further, the fire pit includes a fuel control mechanism for stopping or modulating the conveyance of fuel when the sensor detects the presence of unburned fuel.

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 system for controlling flame instability. The system may include a nozzle coupled to a fuel supply line, an insulation housing coupled to the nozzle, a combustor coupled to the nozzle via the insulation housing, where the combustor is grounded, a pressure sensor coupled to the combustor and configured to detect pressure in the combustor, and an instability controlling assembly coupled to the pressure sensor and to an alternating current power supply. The instability controlling assembly can control flame instability of a flame in the system based on pressure detected by the pressure sensor by applying a voltage from the alternating current power supply to the system to create an electric field.

A method of monitoring a flame rod of a furnace including: detecting an average current of the flame rod during a burn cycle of the furnace; determining a burn time of the burn cycle of the furnace; and determining a remaining life of the flame rod based on at least the average current and the burn time.

In an embodiment, a system includes a gas turbine controller. The gas turbine controller is configured to receive a plurality of sensor signals from a fuel composition sensor, a pressure sensor, a temperature sensor, a flow sensor, or a combination thereof, included in a gas turbine engine system. The controller is further configured to execute a gas turbine model by applying the plurality of sensor signals as input to derive a plurality of estimated gas turbine engine parameters. The controller is also configured to execute a flame holding model by applying the plurality of sensor signals and the plurality of estimated gas turbine engine parameters as input to derive a steam flow to fuel flow ratio that minimizes or eliminates flame holding in a fuel nozzle of the gas turbine engine system.

One or more techniques and/or systems are disclosed for a portable heater that may be used in an area used for human occupancy, to provide heat to that area. Such a heater can be portable, and comprise an environmental detector that senses ambient air conditions, and may provide data used to shut down the heater in threshold conditions. In one implementation, a portable heater for use in high altitudes can comprise a housing configured for portability, in which a combustion region and a fuel supply component are disposed. The heater can comprise an environmental detector with a flameless sensor configured to detect an ambient level of a constituent of the atmosphere, and generate a signal indicative of the constituent level; and a sensor interface that can control flow of fuel from the fuel supply, based at least upon a signal received from the sensor.