Abstract: A device to control a gas-fired appliance as a function of the composition of a gaseous fuel. The device includes a thermal conductivity sensor emitting a measurement signal dependent upon the thermal conductivity of the gaseous fuel. An analyzing unit receives the measurement signal and uses it to develop a control signal dependent upon the composition of the gaseous fuel. A control unit receives the control signal and uses it to control the operating parameters of the gas-fired appliance, in the case of a gas engine particularly the parameters of air/fuel ratio, output and angle of advance. The analyzing unit may include an input interface into which data on the type of gaseous fuel components may be entered, which are used for the generation of the control signal. Preferably the control signal is proportional to the available methane number of the gaseous fuel, whereby the operating parameters of the gas engine are controlled so that the methane number required is adjusted to the methane number available.

Abstract: A device for controlling the flow rate of a fuel gas/air mixture, and/or the ratio between the fuel gas and air in such a mixture. The device includes a body having an air inlet, a fuel gas inlet, a fuel gas/air mixture outlet, a gas-control passage in the body, with the cross-sectional area of the gas-control passage being variable via a control device for controlling the flow of fuel gas through the device, and an adjustable air-control passage for adjusting the flow of air through the device. The air-control and gas-control passages are configured and disposed in the body in such a way that they cooperate to also form an area within the body where said controlled fuel gas and air flows are combined and mixed.

Abstract: A process and apparatus for the combustion-less measurement and/or regulation of the feeding of quantities of heat to gas combustion devices, particularly natural-gas combustion devices. A fuel gas or a partial stream of the fuel gas is fed through a fuel gas line containing at least one flow resistor which produces a laminar flow and a pressure drop. The gas volume flow and/or the pressure drop over at least one flow resistor is measured by a volume flow metering device and a difference pressure regulator, respectively, the pressure drops and/or volume flows which are not measured being maintained constant. A device compensates for the influence of temperature on the system is compensated. The measured value(s) in accordance with the formula described in the specificationf (H)=a+b.multidot.n.sup.c .multidot..rho..sup.dis a measure of the heat content of the flowing gas and results in a signal which serves for measurement and/or regulation.