15b Tank-Integrated Heat Exchanger for Boil-Off Reduction

Widespread adoption of renewable energy and heavy duty zero-emission vehicles requires innovation of liquid hydrogen storage and fueling technologies. Though traditional vacuum jacketed dewars are suitable for long term storage, many emerging heavy duty hydrogen vehicles will require continuous hydrogen usage and long duty cycles to recoup investments. The Protium Company (Protium) has designed a novel liquid hydrogen tank with integrated heat exchanger which eliminates the need for a standalone vaporizer and does not require a vacuum jacket, reducing capital and operating expenses. The tank can be configured with broad area cooling channels to reduce or eliminate boil-off during long latency periods. The proposed project will determine the technical feasibility of Protium’s tank design for large scale (> 60 kg) storage applications. During Phase I, The Protium Company will (1) develop a transient model of the tank-integrated heat exchanger as an analogue to a traditional vacuum- insulated liquid hydrogen tank design, (2) carry out a design study to optimize the tank design for reduction of boil-off during a liquid hydrogen transfer into the tank, and (3) integrate broad area cooling channels into the transient model to determine the characteristics of a zero boil- off design. Follow-on Phase II efforts will include manufacturing a 60 kg prototype tank to demonstrate viability and compare empirical boil-off measurements to modeled results. The success of the proposed project will revolutionize liquid hydrogen as a zero-emission fuel for several transportation sectors. Liquid hydrogen has emerged as the critical fuel for zero- emission, long range electric aircrafts and air taxis due to its high specific energy. Similarly, studies from Sandia National Laboratories have concluded that liquid hydrogen powered fuel cell vessels provide the most versatility, highest efficiency, and are the only feasible zero- emission option for large vessels. Additionally, Protium’s liquid hydrogen tank concept has wide implications for US military operations. Nearly every branch of the US military is exploring hydrogen-electric vehicles for the reduced thermal and acoustic signature, as well as the increased reliability inherent of an electric powertrain. Protium’s fuel tank with integrated heat exchanger can simplify operations and logistics, making liquid hydrogen financially feasible for the aerospace and maritime sectors in the near future.