Method and system for filling tanks of hydrogen-fueled vehicles

A system for filling tanks of fuel cell electric vehicles with pressurized hydrogen, comprising:

• a liquid hydrogen storage vessel;
• a liquid hydrogen pump in downstream flow communication from the storage vessel and is adapted and configured to receive a stream of liquid hydrogen from the storage vessel and pump and pressurize the liquid hydrogen stream to produce a stream of pressurized hydrogen;
• a first heat exchanger having a warming circuit that is adapted and configured to receive and vaporize a first portion of the pressurized hydrogen stream therein to produce a vaporized hydrogen stream and also having a cooling circuit;
• a bypass circuit adapted and configured to receive a second portion of the pressurized hydrogen stream from the liquid hydrogen pump;
• a vaporized hydrogen circuit adapted and configured to receive the vaporized hydrogen stream;
• a buffer vessel feed conduit adapted and configured to receive the vaporized hydrogen stream from the vaporized hydrogen circuit and the second portion of the pressurized hydrogen stream from the bypass circuit to form a combined stream;
• a first temperature control valve adapted and configured to control a flow rate of the vaporized hydrogen stream in the vaporized hydrogen circuit;
• a second temperature control valve adapted and configured to control a flow rate of the second portion in the bypass circuit;
• at least one buffer vessel adapted and configured to receive and store the combined stream from said buffer vessel feed conduit until a vehicle tank fill is requested;
• a second heat exchanger having a cooling circuit that is adapted and configured to receive and cool the combined stream from the buffer vessel feed conduit and/or a stream of pressurized hydrogen from the at least one buffer vessel to produce a cooled stream of pressurized hydrogen, the second heat exchanger also having a warming circuit;
• a filling circuit that is comprised of, in flow order, the cooling circuit of the second heat exchanger and at least one filling dispenser that is adapted and configured to engage with a fuel cell electric vehicle so as to allow a tank thereof be filled with the cooled stream of pressurized hydrogen;
• a temperature sensor disposed in the buffer vessel feed conduit that is adapted and configured to measure a temperature of the combined stream;
• a heat exchange fluid loop that is comprised of, in flow order, a surge vessel containing a main heat transfer fluid, a main heat transfer fluid pump adapted and configured to pump the main heat transfer fluid through the heat exchange fluid loop, the cooling circuit of the first heat exchanger, the warming circuit of the second heat exchanger, and the surge vessel, wherein:
• the first heat exchanger is adapted and configured to exchange heat between the relatively warmer main heat transfer fluid with the relatively cooler first portion of the pressurized hydrogen stream to produce the vaporized hydrogen stream and cooled stream of main heat transfer fluid;
• the second heat exchanger is adapted and configured to exchange heat between, on one hand, the relatively warmer combined stream and/or the relatively warmer stream of pressurized hydrogen from the at least one buffer vessel, and on the other hand, the relatively cooler cooled stream of main heat transfer fluid;
• and
• the first and second temperature control valves control the flow rate of the vaporized hydrogen stream and the second portion, respectively, based upon a temperature measured by said temperature sensor;
• and
• a boil-off gas venting circuit in flow communication between a headspace of the storage vessel and an ambient atmosphere of the system, the boil off gas venting circuit comprising a first end that is in downstream flow communication with the headspace, a second end that is selectively open to the ambient atmosphere, and a second warming circuit of the first heat exchanger in between the first and second ends, the boil off gas vent circuit being adapted and configured to receive boil off gas from the headspace, warm the received boil off gas in the second warming circuit through heat exchange with a mass of the first heat exchanger, and vent the warmed boil off gas to the ambient atmosphere via the second end.