Hydrogen liquefaction and recirculation for vehicle refueling
A refueling system for vehicles may include 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, a condensation coil fluidly connected to the inlet tube to receive the gaseous hydrogen and thermally connected to the cryocooler cold tip, a nozzle fluidly connected to the condensation coil and configured to receive liquid hydrogen from the condensation of the gaseous hydrogen; and a coupling mechanism fluidly connected to the nozzle to receive the liquid hydrogen wherein the nozzle is 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 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;
a condensation coil fluidly connected to the inlet tube to receive the gaseous hydrogen and thermally connected to the cryocooler cold tip;
a nozzle fluidly connected to the condensation coil and configured to receive liquid hydrogen from the condensation of the gaseous hydrogen;
a coupling mechanism fluidly connected to the nozzle to receive the liquid hydrogen wherein the nozzle is downwardly movable to fluidly connect from above to an upwards facing tank inlet of a vehicle;
a gas recapture tube configured to fluidly connect to the tank inlet of the vehicle and configured to capture gas released from the tank; and
an outlet tube fluidly connected to the gas recapture tube, and a recirculation loop tube fluidly connected to the outlet tube and the inlet tube.
2 . The refueling system of claim 1 , further comprising:
a sensor disposed between the condensation coil and the nozzle configured to detect the presence of liquid hydrogen.
3 . The refueling system of claim 1 , wherein the circulation loop includes a circulating means configured to move gas from the outlet tube to the inlet tube.
4 . The refueling system of claim 3 , wherein the circulating means is selected from a blower and a pump.
5 . The refueling system of claim 1 , wherein the recirculation loop includes a heat exchanger.
6 . The refueling system of claim 1 , wherein the nozzle is disposed through the gas recapture tube, wherein an outer surface of the nozzle and an inner surface of the gas recapture tube define a flow chamber configured to allow gas to enter the chamber from the tank.
7 . The refueling system of claim 6 , wherein the gas recapture tube further includes a recirculating leg tube fluidly connected to the outlet tube and the flow chamber.
8 . The refueling system of claim 1 , wherein the recirculation loop further includes a vent valve configured to vent gas from the system.
9 . The refueling system of claim 1 , further comprising:
one or more mechanical fasteners that secure the condensation coil to the cryocooler cold tip, the fastener configured to maintain force on the condensation coil to maintain contact between the condensation coil and the cold tip.
10 . The refueling system of claim 9 , wherein the mechanical fastener is selected from a constant-tension bolt clamp and spring clamp.
11 . The refueling system of claim 1 , further comprising:
a seal between the nozzle and the tank inlet.
12 . The refueling system of claim 1 , further comprising:
a vapor-cooled shield fluidly connected to the gas recapture tube and to the outlet tube.