Direct liquefaction for vehicle refueling
A refueling system may include an inlet tube that fluidly connects to a container containing gaseous hydrogen, a cryocooler including a cold tip and a cold head, the cold tip driven to a hydrogen liquefaction temperature by the cold head, a condensation chamber fluidly connected to the inlet tube to receive the gaseous hydrogen and thermally connected to the cryocooler cold tip, a catalyst disposed in the condensation chamber and that conducts ortho-to-para hydrogen conversion. The cryocooler cold tip absorbs a resulting exothermic reaction. The refueling system may also include a funnel fluidly connected to the condensation chamber and that receives liquid hydrogen from the condensation of the gaseous hydrogen, and a coupling mechanism fluidly connected to the funnel to receive the liquid hydrogen and having a nozzle downwardly movable to fluidly connect from above to an upwards facing tank inlet of a vehicle.
1 . A refueling system for vehicles, comprising:
an inlet tube configured to fluidly connect to a container containing gaseous hydrogen;
a series of cryocoolers each including a cold tip and a cold head, the cold tip of a last cryocooler in the series configured to be driven to a hydrogen liquefaction temperature of between 20 and 25 K by the cold head of the last cryocooler;
a series of heat exchangers each thermally coupled to a respective one of the series of cryocoolers, the series of heat exchangers serially fluidly coupled to the inlet tube so that the gaseous hydrogen flows from a first heat exchanger in the series to a second heat exchanger in the series and to one or more subsequent heat exchangers in the series;
each cryocooler sized to progressively reduce temperature of the gaseous hydrogen to liquefy the gaseous hydrogen into liquid hydrogen and to remove heat in an ortho-to-para hydrogen conversion process using a catalyst;
a storage Dewar configured to store the liquid hydrogen;
a coupling mechanism fluidly connected to the storage Dewar to receive the liquid hydrogen and having a nozzle downwardly movable to fluidly connect from above to an upwards facing tank inlet of a vehicle; and
an isolation valve fluidly connected to the nozzle, the isolation valve pneumatically actuated using gaseous helium.
2 . The refueling system of claim 1 , comprising:
a bellows disposed with respect to the nozzle and fuel tank inlet, the bellows moveable vertically for supplying liquid hydrogen to the fuel tank inlet to provide a confined volume when a connection is made between the nozzle and the fuel tank inlet.
3 . The refueling system of claim 1 , comprising:
an actuator arm configured to connect to a fuel tank cap and including a mechanism configured to, upon the nozzle being fluidly connected from above to the upwards facing tank inlet of the vehicle, actuate to remove the fuel tank cap from the fuel tank inlet, the actuator arm made of two materials to minimize heat leak towards the fuel tank, an upper portion of the actuator rod made of stainless steel and a lower portion of the actuator made of a composite material.
4 . The refueling system of claim 3 , comprising:
a stainless-steel flexure bellows attached to the actuator arm.
5 . The refueling system of claim 1 , comprising:
a pneumatic bladder operably connected to the isolation valve and divided in two halves, a first half receives gaseous nitrogen and a second half receives gaseous helium;
a spring operably connected to the isolation valve to actuate the isolation valve to a closed position;
wherein when the first half and the second half of the bladder are charged up to operating pressure, the bladder actuates the valve to the open position,
wherein release of gaseous nitrogen from the first half discharges the bladder, releasing the isolation valve to the closed position.
6 . The refueling system of claim 1 , comprising:
a fill level sensor incorporated into the nozzle and configured to sense a fill level of the tank of the vehicle, the fill level sensor configured to one of:
inform of a fuel level of the tank of the vehicle, or
cause termination of fueling upon detecting a certain fuel level in the tank.
7 . A refueling system for vehicles, comprising:
an inlet tube configured to fluidly connect to a container containing gaseous hydrogen;
a cryocooler including a cold tip and a cold head, the cold tip configured to be driven to a hydrogen liquefaction temperature of between 20 and 25 K by the cold head;
the cryocooler sized to reduce temperature of the gaseous hydrogen to liquefy the gaseous hydrogen into liquid hydrogen and to remove heat in an ortho-to-para hydrogen conversion process using a catalyst;
a condensation chamber fluidly connected to the inlet tube to receive the gaseous hydrogen and thermally connected to the cryocooler;
the catalyst disposed in the condensation chamber and configured to conduct ortho-to-para hydrogen conversion;
a funnel fluidly connected to the condensation chamber and configured to receive liquid hydrogen from the condensation of the gaseous hydrogen;
a storage Dewar configured to store the liquid hydrogen; and
a coupling mechanism fluidly connected to the storage Dewar to receive the liquid hydrogen and having a nozzle to fluidly connect from above to an upwards facing tank inlet of a vehicle.
8 . The refueling system of claim 7 , comprising:
a liquefier chamber within which the condensation chamber resides, the liquefier chamber having an inlet through which the inlet tube passes and an outlet through which the nozzle passes; and
a vacuum port fluidly connected to the liquefier chamber and configured to connect to a vacuum exerting mechanism to extract gases from a vacuum space of the liquefier chamber.
9 . The refueling system of claim 8 , comprising:
a cryocooler mounting flange disposed at a top portion of the liquefier chamber;
a radiations shield disposed between the cryocooler mounting flange and the condensation chamber; and
wall seals disposed a) between first abutting edges of the radiation shields and a wall of the liquefier chamber and b) between second abutting edges of the radiation shield and a portion of the cryocooler located inside the liquefier chamber.
10 . The refueling system of claim 7 , comprising:
a bellows disposed with respect to the nozzle and fuel tank inlet, the bellows moveable vertically for supplying liquid hydrogen to the fuel tank inlet to provide a confined volume when a connection is made between the nozzle and the fuel tank inlet.
11 . The refueling system of claim 7 , comprising:
an actuator arm configured to connect to a fuel tank cap and including a mechanism configured to, upon the nozzle being fluidly connected from above to the upwards facing tank inlet of the vehicle, actuate to remove the fuel tank cap from the fuel tank inlet, the actuator arm made of two materials to minimize heat leak towards the fuel tank, an upper portion of the actuator rod made of stainless steel and a lower portion of the actuator made of a composite material.
12 . The refueling system of claim 11 , comprising:
a stainless-steel flexure bellows attached to the actuator arm.
13 . The refueling system of claim 7 , comprising:
an isolation valve fluidly connected to the nozzle, the isolation valve pneumatically actuated using gaseous helium.
14 . The refueling system of claim 13 , comprising:
a pneumatic bladder operably connected to the isolation valve and divided in two halves, a first half receives gaseous nitrogen and a second half receives gaseous helium;
a spring operably connected to the isolation valve to actuate the isolation valve to a closed position;
wherein when the first half and the second half of the bladder are charged up to operating pressure, the bladder actuates the valve to the open position,
wherein release of gaseous nitrogen from the first half discharges the bladder, releasing the isolation valve to the closed position.
15 . The refueling system of claim 7 , comprising:
a fill level sensor incorporated into the nozzle and configured to sense a fill level of the tank of the vehicle, the fill level sensor configured to one of:
inform of a fuel level of the tank of the vehicle, or
cause termination of fueling upon detecting a certain fuel level in the tank.