Electronic flow sensor

A method for operating a safety shut-off of a liquid gas system for vehicles and/or vehicle trailers for avoiding an unwanted release of gas, the system including at least one gas reservoir connected or connectable to at least one gas consumer via at least one gas line, and a safety shut-off device, the safety shut-off device including an electromagnetic gas valve for shutting off a gas supply to the liquid gas system, a flow sensor for periodically detecting a current gas flow Fa being discharged from the at least one gas reservoir, an evaluation unit that, for each time a current gas flow Fa is detected by the flow sensor, compares the current gas flow Fa to an immediately preceding detecting gas flow Fv, and an electronic unit which controls the electromagnetic gas valve for shutting off the gas supply, the method comprising the following steps:

• a) detecting, using the flow sensor, a current gas flow Fa exiting the gas source;
• b) comparing, using the evaluation unit, the current gas flow Fa to a previous gas flow;
• and
• c) interrupting, using the electronic unit, the gas supply via the electromagnetically controlled gas valve when the comparing step finds the current gas flow Fa differs from the immediately preceding detected gas flow Fv by more than a maximum admissible gas flow change rate Δmax, such that the gas supply is interrupted when the following condition is fulfilled:
• Fa −Fv>Δmax.

A safety shut-off device for a liquid gas system having at least one gas consumer for a vehicle and/or vehicle trailer for avoiding an unwanted release of gas, the device comprising:

• a) an electromagnetic gas valve for shutting off a gas supply to the liquid gas system;
• b) a flow sensor for periodically detecting a current gas flow Fa being discharged from a gas source;
• c) an evaluation unit that, for each time a current gas flow Fa is detected by the flow sensor, compares the current gas flow Fa to an admissible maximum gas flow Fmax;
• and
• d) an electronic unit which controls the electromagnetic gas valve for shutting off the gas supply when the evaluation unit detects a current gas flow Fa which is higher than the admissible maximum gas flow Fmax, wherein the admissible maximum gas flow Fmax is calculated according to a sum of all gas flow consumption values Fs of the gas consumers of the liquid gas system, and wherein the admissible maximum gas flow Fmax is updated by current and/or expected gas consumption values signaled by the gas consumers.

A method for operating a safety shut-off of a liquid gas system for vehicles and/or vehicle trailers for avoiding an unwanted release of gas, the system including at least one gas reservoir connected or connectable to at least one gas consumer via at least one gas line, and a safety shut-off device, the safety shut-off device including an electromagnetic gas valve for shutting off a gas supply to the liquid gas system, a flow sensor for periodically detecting a current gas flow Fa being discharged from the at least one gas reservoir, an evaluation unit that, for each time a current gas flow Fa is detected by the flow sensor, compares the current gas flow Fa to an admissible maximum gas flow Fmax that is calculated according to a sum of all gas flow consumption values Fs of the gas consumers of the liquid gas system, and an electronic unit which controls an electromagnetically controlled gas valve for shutting off the gas supply, the method comprising the following steps:

• a) detecting, using the flow sensor, a current gas flow Fa exiting the gas source;
• b) comparing, using the evaluation unit, the current gas flow Fa to an admissible maximum gas flow Fmax;
• and
• c) interrupting, using the electronics unit, the gas supply via an electromagnetically controlled gas valve when the comparing step finds the current gas flow is greater than the admissible maximum gas flow Fmax, and wherein the admissible maximum gas flow Fmax is updated by current and/or expected gas consumption values signaled by the gas consumers.