Method for estimating volume and pressure in a tank, and pressure losses connected with a dispensing station

A method (10) for estimating the volume (V) of a pressurized gas tank (2) and the pressure (Ptank) of the gas in said tank (2), the tank (2) being supplied by a dispensing station (1) comprising, in this order:

• a source (3) of said gas, a control valve (7) and a dispenser (5) which is connected to the tank (2), the method (10) comprising the following steps:
• a) measuring (SO) a first value (Ptank_mes) for the pressure (Ptank) of the gas in the tank (2) by measuring the pressure (Pdisp) of the gas at the dispenser (5), the control valve (7) being closed,
• b) injecting (S1) a quantity (Δm) of gas into the tank (2),
• c) determining (S2) during the injection (S1) a value for the mass flow rate ({dot over (m)}), a value for the pressure (Pdisp) and a value for the temperature (Tdisp) of the gas at the dispenser (5);
• and a value for the ambient temperature (Tamb) in a region surrounding the tank (2),
• d) measuring (S3) a second value (Ptank_mes) for the pressure (Ptank) of the gas in the tank (2) by measuring the pressure (Pdisp) of the gas at the dispenser (5), the control valve (7) being closed,
• e) determining (S4) a maximum volume (Vmax) corresponding to a first reference tank, and a minimum volume (Vmin) corresponding to a second reference tank,
• f) determining (S5) the volume (V) of the tank (2) and the pressure (Ptank) of the gas in the tank (2), through an iterative search for the root of a function (P) expressing the difference between the pressure (Ptank) of the gas in the tank (2) and the second value (Ptank_mes) for the gas pressure (Pdisp) measured at the dispenser (5) during the measurement (S3), the iterative search being performed in an interval ([Vmin, Vmax]) that is defined between the minimum volume (Vmin) and the maximum volume (Vmax).