Fluid measurement system and fluid measurement method

A fluid measurement system comprising:

• a first load sensor and a second load sensor that are disposed on a same pipe carrying a two-phase fluid including a liquid phase and a vapor phase, the first and second load sensors being spaced apart by a predetermined distance;
• each of the first load sensor and the second load sensor being configured to output time-series measurement results in real time;
• and
• a measurement controller configured to calculate a flow velocity of the two-phase fluid flowing through the pipe based on first output that is output from the first load sensor and second output that is output from the second load sensor,
• wherein the measurement controller performs a process including
• (a) acquiring the first output and the second output as respective time-series measurement results;
• storing the acquired time-series measurement results in a memory corresponding to the first period of time;
• updating the stored time-series measurement results by discarding temporally older measurement results and adding newly acquired measurement results so as to shift the first period of time;
• and
• repeatedly calculating, based on the updated time-series measurement results including the newly acquired measurement results, a first time difference between the first output and the second output while shifting the first period of time,
• (b) calculating a second time difference by:
• calculating a frequency of occurrence of a plurality of first time differences obtained in a second period of time that is greater than the first period of time;
• excluding, from the plurality of first time differences, time differences of zero;
• and
• selecting first time differences included in a time difference section having a mode in the frequency of occurrence and determining the second time difference based only on the selected first time differences, and
• (c) calculating the flow velocity of the two-phase fluid based on the second time difference.