GASEOUS HYDROGEN FUELING METHODS

1 . A method of filling a tank with gaseous fuel, comprising:

delivering a gas from a filling station to the tank;

while delivering the gas:

communicating a gas temperature measurement and a gas pressure measurement from the tank to the filling station;

based on the gas temperature measurement, computing a time remaining (tremain_Tgas) for a temperature of the gas in the tank to reach a predetermined target temperature;

based on the gas temperature and gas pressure measurements, computing a time remaining (tremain_SOC) for a state of charge of the gas in the tank to reach a predetermined target state of charge;

determining a difference between (tremain_Tgas) and (tremain_SOC); and

modulating a pressure ramp rate of the gas being delivered so as to reduce the difference between (tremain_Tgas) and (tremain_SOC).

2 . The method of claim 1 , wherein the tank is a hydrogen vehicle gas tank.

3 . A method of filling a tank with gaseous fuel, comprising:

delivering a gas from a filling station to the tank, at a ramp pressure;

communicating a gas temperature measurement and a gas pressure measurement from the tank to the filling station;

increasing the ramp pressure at a pressure ramp rate (PRR_calculated) which is calculated using a preselected fueling protocol (PRR_calculated), until the ramp pressure exceeds a threshold value (P_threshold);

once the ramp pressure exceeds P_threshold:

based on the gas temperature and gas pressure measurements, computing a state of charge (SOC) based on density using an equation of state;

computing a rate of change of SOC (SOCRR) over a lookback period (t_lookback), and based on SOCRR, computing a time remaining (tremain_SOC) for a state of charge of the gas in the tank to reach a predetermined target state of charge;

computing a new pressure ramp rate PRR_SOC;

comparing PRR_SOC to (PRR_calculated); and

in response to PRR_SOC being lower than PRR_calcuated, setting the pressure ramp rate to PRR_SOC.

4 . The method of claim 3 , wherein computing a new pressure ramp rate includes:

computing the rate of change of the ramp pressure (PRR_lookback) over a lookback period (t_lookback), and based on PRR_lookback, computing a time remaining (tremain_PRR) for the ramp pressure to reach a predetermined value (P_ramp_target);

determining a difference between (tremain_PRR) and (tremain_SOC); and

in response to this difference being a negative value, computing the new pressure ramp rate PRR_SOC based on tremain_SOC, so as to reduce an absolute value of the difference between tremain_PRR and tremain_SOC.

5 . The method of claim 3 , wherein computing a new pressure ramp rate includes:

computing the new pressure ramp rate PRR_SOC based on tremain_SOC.

6 . The method of claim 3 , wherein P_threshold is a preset value.

7 . The method of claim 3 , wherein P_threshold is a value based on a percentage of a nominal working pressure (NWP) of the tank.

8 . The method of claim 3 , wherein P_threshold is a function of P_ramp_target and a pressure drop measured between the ramp pressure and the pressure in the tank.

9 . The method of claim 3 , wherein P_threshold is a function of P_ramp_target and a pressure drop measured between a station pressure and the pressure in the tank.

10 . The method of claim 3 , wherein P_threshold is a function of P_ramp_target and a maximum pressure drop measured between the ramp pressure and the pressure in the tank.

11 . The method of claim 3 , wherein P_threshold is a function of P_ramp_target and a maximum pressure drop measured between the station pressure (P_station) and the pressure in the tank.

12 . The method of claim 3 , wherein P_threshold is a function of P_ramp_target, the current ramp pressure as a percentage of the P_ramp_target, and the SOC_target.

13 . A method of filling a tank with gaseous fuel, comprising:

delivering a gas from a filling station to the tank, at a ramp pressure;

communicating a gas temperature measurement and a gas pressure measurement MP from the tank to the filling station;

increasing the ramp pressure at a pressure ramp rate (PRR_calculated) which is calculated using a preselected fueling protocol (PRR_calculated), until the ramp pressure exceeds a threshold value (P_threshold);

once the ramp pressure exceeds P_threshold:

computing a rate of change of MP (PRR MP ) over a lookback period (t_lookback), and based on PRR MP , computing a time remaining (t remain ) for a pressure of the gas in the tank to reach a predetermined pressure (P target );

computing a new pressure ramp rate PRR taper ; and

setting the pressure ramp rate to the lower of: PRR taper , the PRR calculated by the fueling protocol being utilized (PRR calculated ), and a maximum pressure ramp rate PRR MAX calculated by the fueling protocol being utilized.

14 . A method of filling a tank with gaseous fuel, comprising:

delivering a gas from a filling station to the tank, at a ramp pressure:

communicating a gas temperature measurement (Tgas_high) and a gas pressure measurement from the tank to the filling station;

setting values for a set of parameters (a, b, Tgas_max and Tgas_target);

increasing the ramp pressure at a pressure ramp rate (PRR_calculated) calculated using a predetermined fueling protocol;

computing a pressure drop (DeltaP) as the difference between the ramp pressure (P_ramp) and the tank pressure;

computing a maximum value of the pressure drop (DeltaP_max);

computing a temperature threshold value T_threshold as (DeltaP_max) subtracted from Tgas_target;

in response to the gas temperature being greater than T_threshold:

computing a pressure ramp rate (PRR_threshold);

computing an adaptable denominator (AD) as the maximum value of either “b” or the product of “a” and DeltaP;

computing a new pressure ramp rate (PRR_throttle) as the maximum value of either zero or the product: PRR_threshold times (Tgas_target minus Tgas_high) divided by AD;

comparing PRR_throttle to PRR_calculated; and

in response to PRR_throttle being lower than PRR_calculated, setting the pressure ramp rate to PRR_throttle.

15 . The method of claim 14 , wherein:

The tank is part of a compressed gas storage system having two or more tanks; and

the gas temperature measurement (Tgas_high) represents the highest gas temperature of all of the two or more tanks in the compressed gas storage system.

16 . The method of claim 14 , wherein Tgas_target is an offset (DeltaT) lower than Tgas_max, or is a percentage of Tgas_max.

17 . The method of claim 14 , wherein DeltaP is calculated as the station pressure minus tank pressure.

18 . The method of claim 14 , further comprising computing T_threshold as DeltaP subtracted from the target temperature (Tgas_target).

19 . The method of claim 14 , further comprising computing T_threshold as a percentage of Tgas_target.

20 . A method of filling a tank with gaseous fuel, comprising:

delivering a gas from a filling station to the tank, at a ramp pressure;

setting values for a set of parameters (a, b_min, TMAL, Tgas_max, Tgas_target, Tgas_smooth_threshold, Tgas_diff_factor, and Tgas_diff_multiplier);

communicating a gas temperature measurement (Tgas_high) and a gas pressure measurement from the tank to the filling station;

increasing the ramp pressure at a pressure ramp rate (PRR_calculated) calculated using a predetermined fueling protocol;

computing a pressure drop (DeltaP) as the difference between the ramp pressure and the tank pressure;

computing a maximum value of the pressure drop (DeltaP_max);

computing a triple moving average of Tgas_high with each moving average having a length of TMAL, referred to as Tgas_smooth;

computing a temperature threshold value T_threshold as the product of DeltaP_max times a constant, subtracted from Tgas_target;

in response to Tgas_smooth being greater than T_threshold:

computing a pressure ramp rate (PRR_threshold);

in response to Tgas_smooth being greater than Tgas_smooth_threshold:

computing Tgas_diff as the difference between Tgas_high and Tgas_smooth;

computing a maximum value of Tgas_diff, defined as Tgas_diff_max;

computing Tgas_offset as the product of Tgas_diff_factor and Tgas_diff_max;

computing Tgas_target as Tgas_max minus Tgas_offset;

computing parameter b as the maximum value of either b_min or the product of Tgas_offset_multiplier and Tgas_offset;

computing an adaptable denominator AD as the maximum value of either parameter b or the product of: parameter a and DeltaP;

computing a new pressure ramp rate (PRR_throttle) as the maximum value of either zero or the product of PRR_threshold multiplied by (Tgas_target minus Tgas_smooth) divided by AD;

comparing PRR_throttle to PRR_calculated; and

in response to PRR_throttle being less than PRR_calculated, setting the pressure ramp rate to PRR_throttle.

21 . The method of claim 20 , wherein:

The tank is part of a compressed gas storage system having two or more tanks; and

the gas temperature measurement (Tgas_high) represents the highest gas temperature of all of the two or more tanks in the compressed gas storage system.

22 . The method of claim 20 , wherein T_threshold is computed as the product of DeltaP times a constant, subtracted from Tgas_target.

23 . The method of claim 20 , wherein T_threshold is computed as a percentage of Tgas_target.