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.
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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