Method and system for tank refilling using active fueling speed control

• US 9,347,612 B2
• Filed: 03/15/2013
• Issued: 05/24/2016
• Est. Priority Date: 04/21/2010
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Mathison, Steve
• Primary Examiner(s): NIESZ, JASON KAROL
• Application Number:
  US13/832,311
• Publication Number:
  US 20140202584A1
• Time in Patent Office: 1,166 Days
• Field of Search: 141/4, 141/11, 141/40, 141/47, 141/197
• US Class Current: 1/1
• CPC Class Codes: F17C 2201/0109 with exteriorly curved end-piece
• CPC Class Codes: F17C 2201/054 medium (>1 m3)
• CPC Class Codes: F17C 2203/0604 Liners
• CPC Class Codes: F17C 2203/0619 with two layers
• CPC Class Codes: F17C 2203/0624 with four or more layers
• CPC Class Codes: F17C 2205/0338 Pressure regulators
• CPC Class Codes: F17C 2221/012 Hydrogen
• CPC Class Codes: F17C 2221/033 Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
• CPC Class Codes: F17C 2223/0123 gaseous, e.g. CNG, GNC
• CPC Class Codes: F17C 2223/0153 Liquefied gas, e.g. LPG, GPL
• CPC Class Codes: F17C 2223/0161 cryogenic, e.g. LNG, GNL, PLNG
• CPC Class Codes: F17C 2223/036 Very high pressure (>80 bar)
• CPC Class Codes: F17C 2225/0123 gaseous, e.g. CNG, GNC
• CPC Class Codes: F17C 2225/036 Very high pressure, i.e. above 80 bars
• CPC Class Codes: F17C 2250/043 Pressure
• CPC Class Codes: F17C 2250/0439 Temperature
• CPC Class Codes: F17C 2250/0443 Flow or movement of content
• CPC Class Codes: F17C 2250/0491 Parameters measured at or inside the vessel
• CPC Class Codes: F17C 2250/0495 the indicated parameter is a converted measured parameter
• CPC Class Codes: F17C 2250/0631 Temperature
• CPC Class Codes: F17C 2250/0694 : with calculations
• CPC Class Codes: F17C 2260/022 : Avoiding overfilling
• CPC Class Codes: F17C 2260/023 : Avoiding overheating
• CPC Class Codes: F17C 2260/025 : Reducing transfer time
• CPC Class Codes: F17C 2260/026 : by calculation
• CPC Class Codes: F17C 2265/065 : for refueling vehicle fuel tanks
• CPC Class Codes: F17C 2270/0139 : Fuel stations
• CPC Class Codes: F17C 2270/0168 : by vehicles
• CPC Class Codes: F17C 2270/0176 : Buses
• CPC Class Codes: F17C 5/007 : for individual gas tanks or containers, e.g. in vehicles filling with liquid fuel not under pressure, B60S5/02, B67D7/00
• CPC Class Codes: F17C 5/06 : for filling with compressed gases
• CPC Class Codes: Y02E 60/32 : Hydrogen storage

Abstract

Disclosed is an improved analytical method that can be utilized by hydrogen filling stations for directly and accurately calculating the end-of-fill temperature in a hydrogen tank that, in turn, allows for improvements in the fill quantity while tending to reduce refueling time. The calculations involve calculation of a composite heat capacity value, MC, from a set of thermodynamic parameters drawn from both the tank system receiving the gas and the station supplying the gas. These thermodynamic parameters are utilized in a series of simple analytical equations to define a multi-step process by which target fill times, final temperatures and final pressures can be determined. The parameters can be communicated to the station directly from the vehicle or retrieved from a database accessible by the station. Because the method is based on direct measurements of actual thermodynamic conditions and quantified thermodynamic behavior, significantly improved tank filling results can be achieved.

Claims

1. A method of filling a compressed gas tank, comprising:

determining a fill time t_final predicted to produce a gas final temperature T_final no greater than a target temperature T;

determining a target pressure P_target predicted to produce a state of charge of 100% within the compressed gas tank;

delivering gas to the compressed gas tank at a pressure ramp rate that achieves the target pressure P_target at a conclusion of the determined fill time t_final; and

wherein, while delivering as to the compressed gas tank, the method further comprises;

continuously measuring a pressure and temperature of gas dispensed to the compressed gas tank;

continuously calculating a mass average enthalpy dispensed to the compressed gas tank based on the continuously measured pressure and temperature of the gas dispensed to the compressed gas tank; and

continuously calculating the fill time t_final based on the continuously calculated mass average enthalpy.

2. The method according to claim 1, wherein, while delivering gas to the gas tank, the method comprises:

continuously calculating the pressure ramp rate that achieves the target pressure P_target based on the continuously calculated fill time t_final;

continuously determining a fueling speed based on the continuously calculated pressure ramp rate; and

continuously adjusting the fueling speed to the continuously determined fueling speed while delivering gas to the gas tank.

3. The method according to claim 2, wherein the pressure ramp rate is continuously calculated according to the equation

4. The method according to claim 1, wherein calculating the mass average enthalpy includes:

calculating a current value of the mass average enthalpy based on measured values of the pressure and temperature at the time of calculation;

comparing the calculated current value of the mass average enthalpy to a previously calculated value of the mass average enthalpy and a mass average enthalpy threshold value;

if the calculated current value of the mass average enthalpy is less than the previously calculated value of the mass average enthalpy and the mass average enthalpy threshold value, then set the current value of the mass average enthalpy to equal the mass average enthalpy threshold value; and

if the calculated current value of the mass average enthalpy is greater than or equal to at least one of the previously calculated value of the mass average enthalpy and the mass average enthalpy threshold value, then set the current value of the mass average enthalpy to equal the calculated current value of the mass average enthalpy.

6. The method according to claim 1, further comprising:

calculating an initial hot soak temperature T_HSinit for an initial mass of gas within the compressed gas tank, and determining the fill time t_final through the initial hot soak temperature T_HSinit; and

calculating an initial cold soak temperature T_CSinit for an initial mass of gas within the compressed gas tank, and determining a target pressure P_target through the initial cold soak temperature T_CSinit.

5. A method of filling a compressed as tank, comprising:

determining a fill time t_final predicted to produce a gas final temperature T_final no greater than a target temperature T;

determining a target pressure P_target predicted to produce a state of charge of 100% within the compressed gas tank;

delivering gas to the compressed gas tank at a pressure ramp rate that achieves the target pressure P_target at a conclusion of the determined fill time t_final;

wherein calculating the fill time t_final comprises;

calculating an initial hot soak temperature T_HSinit for an initial mass of gas within the compressed gas tank;

calculating a composite heat capacity value MC according to the equation

19. The method according to claim 5, wherein, while delivering gas to the compressed gas tank, the method comprises:

continuously measuring a pressure and temperature of gas dispensed to the compressed gas tank;

continuously calculating a mass average enthalpy dispensed to the compressed gas tank based on the continuously measured pressure and temperature of the gas dispensed to the compressed gas tank; and

continuously calculating the fill time t_final based on the continuously calculated mass average enthalpy.

7. A method of refueling a hydrogen tank on a hydrogen powered vehicle, comprising:

determining a fill time t_final predicted to produce a final hydrogen temperature T_final no greater than a target temperature T;

determining a target pressure P_target predicted to produce a state of charge of 100%;

delivering hydrogen to the hydrogen tank at a pressure ramp rate that will achieve the target pressure P_target at a conclusion of the determined fill time t_final; and

wherein, while delivering hydrogen to the hydrogen tank, the method further comprises;

continuously measuring a pressure and temperature of hydrogen dispensed to the hydrogen tank;

continuously calculating a mass average enthalpy dispensed to the hydrogen tank based on the continuously measured pressure and temperature of the hydrogen dispensed to the hydrogen tank; and

continuously calculating the fill time t_final based on the continuously calculated mass average enthalpy.

8. The method according to claim 7, wherein, while delivering hydrogen to the hydrogen tank, the method comprises:

continuously calculating the pressure ramp rate that achieves the target pressure P_target based on the continuously calculated fill time t_final;

continuously determining a fueling speed based on the continuously calculated pressure ramp rate; and

continuously adjusting the fueling speed to the continuously determined fueling speed while delivering hydrogen to the hydrogen tank.

9. The method according to claim 8, wherein the pressure ramp rate is continuously calculated according to the equation

10. The method according to claim 7, wherein calculating the mass average enthalpy includes:

calculating a current value of the mass average enthalpy based on measured values of the pressure and temperature at the time of calculation;

comparing the calculated current value of the mass average enthalpy to a previously calculated value of the mass average enthalpy and a mass average enthalpy threshold value;

if the calculated current value of the mass average enthalpy is less than the previously calculated value of the mass average enthalpy and the mass average enthalpy threshold value, then set the current value of the mass average enthalpy to equal the mass average enthalpy threshold value; and

if the calculated current value of the mass average enthalpy is greater than or equal to at least one of the previously calculated value of the mass average enthalpy and the mass average enthalpy threshold value, then set the current value of the mass average enthalpy to equal the calculated current value of the mass average enthalpy.

11. The method according to claim 7, wherein calculating the fill time t_final comprises:

calculating an initial hot soak temperature T_HSinit for an initial mass of hydrogen within the hydrogen tank;

calculating a composite heat capacity value MC according to the equation

12. The method according to claim 7, further comprising:

calculating an initial hot soak temperature T_HSinit for an initial mass of hydrogen within the hydrogen tank, and determining the fill time t_final through the initial hot soak temperature T_HSinit; and

calculating an initial cold soak temperature T_CSinit for an initial mass of hydrogen within the hydrogen tank, and determining a target pressure P_target through the initial cold soak temperature T_CSinit.

13. A method of operating a hydrogen gas filling station, comprising:

obtaining a first set of parametric data corresponding to a hydrogen powered vehicle;

obtaining a second set of parametric data corresponding to station capabilities;

obtaining a third set of parametric data corresponding to a refueling ambient;

calculating a MC value based on the parametric data obtained;

determining a fill time t_final predicted to produce a gas final temperature T_final no greater than a target temperature T and achieve a state of charge of 100% within a tank; and

determining a target pressure P_target predicted to produce a state of charge of 100% within the tank.

14. The method according to claim 13, wherein, while delivering gas to the tank, the method comprises:

continuously measuring a pressure and temperature of gas dispensed to the tank;

continuously calculating a mass average enthalpy dispensed to the tank based on the continuously measured pressure and temperature of the gas dispensed to the tank; and

continuously calculating the fill time t_final based on the continuously calculated mass average enthalpy.

15. The method according to claim 14, wherein, while delivering gas to the tank, the method comprises:

continuously calculating a pressure ramp rate that achieves the target pressure P_target based on the continuously calculated fill time t_final;

continuously determining a fueling speed based on the continuously calculated pressure ramp rate; and

continuously adjusting the fueling speed to the continuously determined fueling speed while delivering gas to the tank.

16. The method according to claim 15, wherein the pressure ramp rate is continuously calculated according to the equation

17. The method according to claim 14, wherein calculating the mass average enthalpy includes:

calculating a current value of the mass average enthalpy based on measured values of the pressure and temperature at the time of calculation;

comparing the calculated current value of the mass average enthalpy to a previously calculated value of the mass average enthalpy and a mass average enthalpy threshold value;

if the calculated current value of the mass average enthalpy is less than the previously calculated value of the mass average enthalpy and the mass average enthalpy threshold value, then set the current value of the mass average enthalpy to equal the mass average enthalpy threshold value; and

if the calculated current value of the mass average enthalpy is greater than or equal to at least one of the previously calculated value of the mass average enthalpy and the mass average enthalpy threshold value, then set the current value of the mass average enthalpy to equal the calculated current value of the mass average enthalpy.

18. The method according to claim 16, wherein determining the fill time comprises:

calculating the fill time t_final according to the equation