Fafnir Gmbh

Wolfgang Schrittenlacher

Stefan Kunter

Klaus Willmer

Christian Maurer

In a method for determining the gas volume flow in gas recirculation at a filling station, by means of a thermal throughflow sensor which is installed in the gas recirculation system of a gasoline pump, measurement values are detected, which represent the mass flow of the gas recirculated during refuelling operations from the respective tank of the motor vehicle to be refuelled into a storage tank of the filling station. Furthermore, information on the composition of the recirculated gas is detected, for example by means of a vapor-pressure curve or a thermal-conductivity measurement cell. The mass flow is determined from the measurement values obtained by the thermal throughflow sensor and the information on the composition of the recirculated gas, calibration data being used. This mass flow is converted into a gas volume flow characteristic of the region of the gasoline pump valves of the gasoline pump. The method is suitable for monitoring the gas recirculation system of the gasoline pump with high accuracy.

Method for determining the gas volume flow in gas recirculation at a filling station

A gas recirculation system at a filling station is controlled during a refuelling process by generating a corrective control signal used for the next refuelling process, to actuate the gas recirculation system and control the gas volume flow, based on the fuel volume flow signal and the gas volume flow signal as well as optionally further signals.

Method for correctively controlling gas recirculation system at filling station

A ventilation-mast monitoring system for filling stations contains a thermal through-flow measuring device () and a hydrocarbon-measuring device (). The thermal through-flow-measuring device () has a heating device and a temperature sensor which is located in the flow path and reacts to the temperature of the heating device, and is configured to sense the gas volume flow escaping from a reservoir tank () via a ventilation mast () of the reservoir tank () of a filling station or entering the reservoir tank (). The hydrocarbon-measuring device () is configured to sense the direction of the gas volume flow escaping from or entering the reservoir tank () via the ventilation mast (). A control device which is configured to receive and to process measuring signals emitted by measuring devices of the system is preferably provided as a further system component.

Ventilation mast monitoring system for filling stations

In a method of measuring the throughflow of a gas mixture, the gas mixture flows past a flow sensor which includes a heating device and a first temperature probe reacting to the temperature of the heating device. A temperature, which is characteristic of the temperature of a liquid above which the gas mixture stands as vapor, is measured with a second temperature probe. A first measurement signal characterizing the composition of the gas mixture and thus its heat dissipation capacity is produced using the known vapor-pressure curve of the liquid and the temperature of the liquid. A second measurement signal characterizing the throughflow of the gas mixture is produced using the heating power supplied to the heating device, the temperature of the first temperature probe and the first measurement signal. The method can be used when monitoring the gas return to a filling system and when controlling the gas pump used therein.

Method of determining the throughflow of a gas mixture

A thermal flow-rate sensor has a flow sensor ( ) and a thermal-conductivity measuring cell ( ). The flow sensor ( ) comprises a first heating device and a first temperature detector, which reacts to the temperature of the first heating device, and can be exposed to a flowing fluid whose flow rate is to be determined. The thermal-conductivity measuring cell ( ) comprises a measuring-cell casing ( ), a second heating device and a second temperature detector which reacts to the temperature of the second heating device. The measuring-cell casing ( ) has at least one opening ( ) arranged for entry of the fluid into the measuring-cell casing ( ).

Growing community of inventors

Hamburg, Germany

Wolfgang Schrittenlacher