Method and system for tank refilling
First Claim
1. A method of filling a compressed gas tank, the method comprising:
- calculating a hot soak initial temperature THSinit for an initial mass of gas within the tank;
determining a projected fill time using THSinit that is predicted to produce a gas final temperature Tfinal no greater than a target temperature T;
calculating a cold soak initial temperature TCSinit for an initial mass of gas within the tank;
calculating for the tank a composite heat capacity value MC corresponding to heat transferred to the tank, a tank assembly and the initial mass of gas within the tank gas, while filling the tank;
determining a target pressure Ptarget using TCSinit that is predicted to produce a target state of charge within the tank; and
delivering gas to the tank at a pressure ramp rate that will achieve Ptarget at the projected fill time.
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Accused Products
Abstract
Disclosed is a simple, 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.
103 Citations
11 Claims
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1. A method of filling a compressed gas tank, the method comprising:
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calculating a hot soak initial temperature THSinit for an initial mass of gas within the tank; determining a projected fill time using THSinit that is predicted to produce a gas final temperature Tfinal no greater than a target temperature T; calculating a cold soak initial temperature TCSinit for an initial mass of gas within the tank; calculating for the tank a composite heat capacity value MC corresponding to heat transferred to the tank, a tank assembly and the initial mass of gas within the tank gas, while filling the tank; determining a target pressure Ptarget using TCSinit that is predicted to produce a target state of charge within the tank; and delivering gas to the tank at a pressure ramp rate that will achieve Ptarget at the projected fill time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of refueling a hydrogen tank on a hydrogen powered vehicle, the method comprising:
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calculating a hot soak initial temperature THSinit for an initial mass of gas within the tank; determining a projected fill time using THSinit that is predicted to produce a final hydrogen temperature Tfinal no greater than a target temperature T; calculating a cold soak initial temperature TCSinit for an initial mass of gas within the tank; calculating for the tank a composite heat capacity value MC corresponding to heat transferred to the tank, a tank assembly and the initial mass of gas within the tank gas, while filling the tank; determining a target pressure Ptarget using TCSinit that is predicted to produce a target state of charge; and delivering gas to the tank at a pressure ramp rate that will achieve Ptarget at the projected fill time.
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Specification