Self-monitoring flow measuring arrangement and method for its operation

A method for operation of a flow measuring arrangement includes a pipeline system flowed through by a medium;

• a control device installed in said pipeline system on the inlet side, which varies a flow rate of the total medium flowing into said pipeline system according to a predetermined, time-dependent periodic change profile, at least one flow measuring device installed in said pipeline system, which is located at a measuring location, which is located downstream of said control device in the flow direction, and through which the medium flowing through said pipeline system flows, and which measures the flow rate of the medium at the measuring location;
• and a monitoring unit, which, based on said predetermined, time-dependent periodic change profile and the flow rates measured at said measuring location, monitors whether said measured flow rates follow said predetermined, time-dependent periodic change profile, and outputs an error report, when at least one of said measured flow rates deviates from said predetermined, time-dependent periodic change profile, the method comprising the steps of:
• predetermining a bandwidth, within which the measured flow rates should follow the predetermined, periodic change profile;
• and
• outputting an error report as soon as at least one of the measured flow rates lies outside the bandwidth.

The method for detecting leaks in the pipeline system of a flow measuring arrangement, comprising:

• a pipeline system flowed through by a medium;
• a control device installed in said pipeline system on the inlet side, which varies a flow rate of the total medium flowing into said pipeline system according to a predetermined time-dependent periodic change profile, at least one flow measuring device installed in said pipeline system, which is located at a measuring location, which is located behind said control device in the flow direction, and through which the entire medium flowing through said pipeline system flows, and which measures the flow rate of the medium at the measuring location;
• and
• a monitoring unit, which, based on said predetermined time-dependent change profile and the flow rates measured at said measuring locations, monitors whether said measured flow rates follow said predetermined time-dependent change profile, and outputs an error report, when at least one of said measured flow rates deviates from said predetermined, time-dependent change profile, and which has at least two flow measuring devices, comprising the steps of:
• based on flow rates measured over a period of time by two of the flow measuring devices installed in the pipeline system, total quantity of medium flowing through the pipeline system past the two associated measuring locations in the period of time is determined;
• it is checked, whether the two quantities of medium deviate from one another,
• it is checked, whether the flow rates measured during the period of time by the two flow measuring devices both follow the predetermined time-dependent change profile during the period of time;
• and
• a leak in the pipeline system located between the two associated measuring locations is diagnosed, when the two quantities of medium deviate from one another and the flow rates measured by the two flow measuring devices during the period of time both follow the predetermined time-dependent change profile.