Method and measuring apparatus for determining specific quantities for gas quality
AssigneeMems AG
InventorPhilippe Pretre
Life of this patent
Estimating the term…
Abstract
A method and a measuring apparatus for determining specific quantities for the gas quality in which the gas or gas mixture flows through an ultrasonic flow sensor as well as through a microthermal sensor, and the former is used for determining the sound and flow velocity and the latter for determining the thermal conductivity and the thermal capacity of the gas or gas mixture. The sound velocity, the thermal conductivity and the thermal capacity are subsequently used for the correlation of the specific quantities for the gas quality.
Claims17
A method for determining a quantity for a gas quality comprising:
- moving a gas or gas mixture through an ultrasonic flow measuring device and over a microthermal sensor;
- determining a temperature of the gas or gas mixture using a temperature sensor;
- determining a pressure of the gas or gas mixture using a pressure sensor;
- determining a flow velocity (vx) or volumetric flow and determining a sound velocity (cs) of the gas or gas mixture based on information sensed by the ultrasonic flow sensor;
- determining a density of the gas or gas mixture based on a correlation with the sound velocity (cs);
- calculating a mass flow of the gas or gas mixture based on the density and flow velocity (vx) or the volumetric flow;
- determining a thermal conductivity of the gas or gas mixture at one or several temperatures;
- determining a flow factor (φ) based on a flow signal of the microthermal sensor;
- determining a thermal capacity (cp) or a quantity dependent on the thermal capacity from the flow factor (φ) and the mass flow and the thermal conductivity;
- and
- determining the quantity for the gas quality using a correlation with the sound velocity and the thermal conductivity and either the thermal capacity or the quantity depending on the thermal capacity.
A measuring apparatus for determining a quantity for a gas quality or for determining energy consumption comprising:
- an ultrasonic flow sensor configured to measure at least one of a sound velocity and a flow velocity of the gas,
- a pressure sensor configured to measure a pressure of the gas,
- a temperature sensor configured to measure a temperature of the gas,
- a microthermal sensor configured to measure at least one of a thermal conductivity of the gas and a thermal capacity of the gas or a quantity dependent on the thermal capacity, and
- an evaluation unit configured to determine the quantity for the gas quality or the energy consumption based on the sound velocity, the thermal conductivity and either the thermal capacity or the quantity dependent on the thermal capacity.
A method to determine a value of a gas quality comprising:
- collecting information regarding a flow of a gas or gas mixture using an ultrasonic flow sensor, a microthermal sensor, temperature sensor, and a pressure sensor;
- based on the collected information, calculating parameters for the flow including at least one of a flow velocity and volumetric flow, a sound velocity, a density, a thermal conductivity, and a flow factor derived from the flow signal of the microthermal sensor;
- using the parameters, calculating for the flow a mass flow and a thermal capacity or a factor dependent on the thermal capacity of the flow, and
- determining the value of the gas quality based on the sound velocity, the thermal conductivity and the thermal capacity or the factor dependent on the thermal capacity.
Dependencies are inferred from the claim text.