A system for checking high fluid pressure and low fluid pressure limit switches for valves and fluid supply to a fluid consumption appliance. The system may incorporate one or more pressure sensors at a fluid valve to detect an amount of fluid pressure. The one or more pressure sensors may be connected to a processor. The high fluid pressure and low fluid pressure sensor limit switches may also be connector to the processor. A display and user control may be connected to the processor.

A fuel sub-metering mechanism for appliances that consume fuel. Each appliance may have a firing rate indicator. An individual fuel line may be connected to each appliance. A main fuel line may be connected to individual fuel lines. A meter may be connected to the main fuel line. A processor may be connected to the firing rate indicators and to the meter. The meter may measure total fuel consumption by the appliances. The processor may provide a sub-meter estimate of fuel consumed by each appliance. The sub-meter estimate may be based at least in part on a firing rate of the respective appliance and the total fuel consumption as indicated by the meter.

A method for commissioning a gas valve assembly for controlling fuel flow to a combustion appliance. An example method for commissioning the gas valve assembly may include initiating a commissioning mode in the controller of the gas valve assembly. Once in the commissioning mode, inputting a user defined initial air to fuel (A/F) ratio, activating the combustion appliance, setting a burner load of the combustion appliance to a set burner load, inputting a desired A/F ratio for the set burner load, running the combustion appliance at the burner load with the desired A/F ratio, and observing the operation of the combustion appliance. The method may further include saving the desired A/F ratio for the set burner load to the controller of the gas valve assembly and exiting the commissioning mode.

A gas turbine and a method for operating a gas turbine having a fuel gas monitoring system are presented. The fuel gas monitoring system may provide a measurement of a parameter of a fuel gas in real time. An operation of a gas turbine may be optimized to adapt variation in hydrocarbon content of a fuel gas from the measurement. The fuel gas monitoring system may provide an optical, flow through, online monitoring of fuel gas composition.

In a modulating gas burner, the mixing ratio of a gas/air mixture is controlled over a modulation range of the gas burner by a pneumatic controller. During burner on phases, the combustion quality is monitored via a combustion quality sensor. The combustion quality is used to detect tolerances of the pneumatic controller and/or a potentially changing behavior of the pneumatic controller by checking if the combustion quality is inside or outside a defined combustion quality range. When the combustion quality is inside the defined combustion quality range, the mixing ratio of gas and air of the gas/air mixture is not changed. When the combustion quality is outside the defined combustion quality range, the mixing ratio of gas and air of the gas/air mixture is changed by adjusting a gas throttle to compensate for tolerances of the pneumatic controller and/or for a potentially changing behavior of the pneumatic controller.

Method for operating a gas burner appliance (10), the gas burner appliance com-prising: a combustion chamber (11) in which a defined gas/air mixture is combusted after combustion has been started; a mixing device (25) to provide said gas/air mixture by mixing an air flow provided by an air duct (15) with a gas flow provided by a gas duct (16); a fan (14) to provide the air flow or the flow of the gas/air mixture; a gas safety valve unit (19) assigned to the gas duct to open or close the gas duct; a gas flow modulator (18) or a gas flow regulator (28) assigned to the gas duct to keep a mixing ratio of the defined gas/air mixture constant over the modulation range of the gas burner appliance; an absolute pressure sensor (21) positioned between the gas safety valve unit and the mixing device, wherein the gas burner appliance is operated to determine the air flow resistance of the same by executing the following steps before combustion becomes started: Measuring a first absolute pressure by the absolute pressure sensor (21) when the gas safety valve unit (19) is closed and when the fan (14) is stopped. Measuring a second absolute pressure by the absolute pressure sensor (21) when the gas safety valve unit (19) is closed and when the fan (14) is running. Determining a pressure difference between the first absolute pressure and the second absolute pressure. Determining on basis of the pressure difference the air flow resistance of the gas burner appliance.

A furnace includes a combustion blower and one or more pressure switches. In some cases, the one or more pressure switches may be used to calculate one or more operating points for the combustion blower. Additional operating points may be calculated by interpolation and/or extrapolation, as appropriate. The furnace may temporarily alter these operating points as necessary to keep the furnace safely operating in response to minor and/or transient changes in the operating conditions of the furnace.

A method is disclosed for diagnosing a valve assembly having valve members serially arranged along a flow channel of the valve assembly connecting at least one inlet and at least one outlet of the valve assembly. All of the serially arranged valve members of the valve assembly are opended to allow fluid to flow through the flow channel. The flow of fluid through the flow channel is measured by at least one sensor. At least one of the valve members is openend, and at least one sensor checks for fluid leakage caused by at least one faulted valve member. The at least one sensor may include a flow sensor, e.g., a mass flow sensor.

A gas appliance comprises a combustion device, an ignitor, a gas valve, a blower, a detecting device, and a control device. A control method thereof comprises: the control device is operated in a detection mode in which the control device controls the ignitor to ignite and controls the gas valve as well as the blower to provide a fixed gas flow and a fixed air flow to the combustion device. After igniting the flames, the control device determines burning states detected by the detecting device; if matching a first state, the control device controls the gas valve and the blower in correspondence to a first control data of the first natural gas; if matching the second state, the control device controls the gas valve and the blower in correspondence to a second control data of the second natural gas. In this way, the gas appliance is suitable for burning natural gas generating various heating values.

The apparatus and method according to the present invention are adapted to adjust, in a combustible gas burner, a mixture of gas formed by a first gas and a second combustible gas, wherein the gas mixture is provided through the appropriate mixing of an amount of said first gas by means of a first adjustment element and an amount of said combustible gas by means of a second adjustment element. Said first or second adjustment elements are managed, during operation, by a controller, which processes the data coming from at least two sensors.