A method for the failsafe and lean ignition of a fuel gas-air mixture on a gas burner (6), which is mixed in a mixing device (4) arranged upstream of the gas burner (6). A control valve (2) along the fuel gas flow path has an actuator (21) and a throttle element (23), moved by the actuator (21), for the closed-loop control of a flow rate of the fuel gas flowing into the mixing device (4). A test is performed to determine whether the throttle element (23) is in the throttle reference position when the actuator (21) is in the actuator reference position. The throttle element (23) is moved in a flow rate-increasing manner starting at a start time (tD). The flow rate-increasing movement of the throttle element (23) is stopped as soon as at least one of multiple predetermined termination conditions occurs.

A gas meter (10) includes a normal measurement mode in which the flow rate is measured in a predetermined sampling period and a detailed measurement mode in which the flow rate is measured in a sampling period shorter than the predetermined sampling period in the normal measurement mode. A center device (40) gives an instruction to the gas meter (10) to measure the flow rate in the detailed measurement mode. The center device (40) further collects flow rate data measured in the detailed measurement mode from the gas meter (10), and generates, based on the collected flow rate data, failure diagnosis information for diagnosing a failure in a gas appliance. With this configuration, the failure part in the gas appliance can be remotely identified, which accelerates the repair work.

A method of preventing blockage of circulating bed material in a circulating fluidized bed reactor includes collecting a continuously flowing bed of solid particles in a gas lock in a return leg of a reactor, measuring gas lock bed pressure values within the bed of the particles, generating a gas lock bed height indication signal on the basis of measured gas lock bed pressure values. A definition stage includes defining and storing to a control system a range of normal gas lock bed height indication signals, formed in normal circulation flow conditions, as a function of the reactor load, and defining and storing to the digital control system a reactor load dependent alarm criterion. The method includes comparing a current gas lock bed height indication signal with the reactor load dependent alarm criterion, and decreasing the reactor load if the current indication signal fulfils the reactor load dependent alarm criterion.

A device for controlling a fuel-oxidizer mixture for a premix gas burner, comprises: an intake duct for admitting the mixture into the burner; an injection duct, connected to the intake duct to supply the fuel; a monitoring device for checking the state of combustion in the burner; a gas regulating valve; a fan located in the intake duct; a control unit for controlling the speed of rotation of the fan between a first and a second rotation speed, corresponding to a minimum flow rate of oxidizer (Qmin) and a maximum flow rate of oxidizer (Qmax), respectively; a regulator coupled to the intake duct and having a first aperture, adjustable through a first shutter, and a second aperture, adjustable through a second shutter. The control unit is configured to drive the gas regulating valve in real time.

A motor controller for a burner system includes an inverter that supplies current to a motor that rotates a draft inducer fan. A processor is coupled to the inverter and receives a signal from a system controller, and in response instructs the inverter to supply a first current, during a first period, to the motor to rotate the fan to produce a first mass flow through the burner system, the first mass flow having a first mass flow rate greater than a threshold to actuate a vacuum switch. The processor then instructs the inverter to supply a second current, during a second period starting at an expiration of the first period, to the motor to rotate the fan to produce a second mass flow through the burner system, the second mass flow having a target mass flow rate for normal operation of the burner.

A method for evaluating a quasi-stationary pressure difference detectable by a sensor at a gas boiler. The gas boiler has a mixing device (4), a fan (5), a main flow regulator (3), .a control valve (2) and a safety valve (1). The sensor detects a differential pressure between a pressure (p2) at a measuring point upstream of the main flow regulator (3) and downstream of the control valve (2) and a reference pressure (p0, p1) at a reference measuring point. The sensor transmits a signal to an electronic evaluation system. The electronic evaluation system compares the differential pressure during a pre-purge phase, wherein the safety valve (1) is closed, with the differential pressure after the pre-purge phase and detects an error by the comparison.

A combustion air proving (CAP) system for a burner assembly having a burner for providing heated air to a location, a controller, and a back plate, where outside air is fed to the burner via a conduit. The CAP system is connected to an inlet of the system. An outlet of the system is connected to the burner via the back plate. A damper within the system is translatable between open and closed positions for allowing and blocking air flow, respectively. A sensor measures an air flow parameter of air flow to the burner. The sensor communicates with the controller, which shuts down the burner if the parameter measured by the sensor meets a predetermined threshold value. An assembly installer may test for proper sensor and controller functions by translating the damper to the closed position and blocking outside air flow.

A method and device for verifying the integrity of each operator of a gas valve including two operators disposed in succession on a passage path for the gas directed to a burner; the operator being subjected to command action by a corresponding actuator controlled by a command and control unit adapted to sense the presence of the flame in the burner, which is correlated with the gas flow rate reaching this burner. Each operator is made to close alternately, with corresponding cessation of gas feed to the burner and successive sensing of the extinguishing of the flame at the burner within a predefined time period, power to these operators being completely interrupted if it is sensed after said time period that the flame is extinguished.

A combustion air proving (CAP) system for a burner assembly having a burner for providing heated air to a location, a controller, and a back plate, where outside air is fed to the burner via a conduit. The CAP system, is connected to an inlet of the system. An outlet of the system is connected to the burner via the back plate. A damper within the system is translatable between open and closed positions for allowing and blocking air flow, respectively. A sensor measures an air flow parameter of air flow to the burner. The sensor communicates with the controller, which shuts down the burner if the parameter measured by the sensor meets a predetermined threshold value. An assembly installer may test for proper sensor and controller functions by translating the damper to the closed position and blocking outside air flow.

A method for determining an estimate of the specific gravity of a fuel for a gas turbine engine is disclosed. The gas turbine engine includes a fuel control valve and one or more fuel injectors. The method includes determining a first estimate of the specific gravity based on an orifice flow model of the fuel control valve. The method also includes determining a second estimate of the specific gravity based on a combined orifice flow model of the one or more fuel injectors. The method further includes recursively filtering the first estimate and the second estimate to determine a third estimate of the specific gravity.