BMW Hydrogen 7 - production-ready, hydrogen-gasoline V12 Saloon

Gaseous hydrogen able to escape in this way is diluted in a venturi pipe and oxidated in a catalyst to form vapour. The period in which a half-full hydrogen tank will be emptied completely in a controlled process is about 9 days, and even then the car is still able to cover approximately 20 kilometres or 12 miles in the hydrogen mode with the fuel remaining in the tank.

While driving, defined conversion of liquid into gaseous hydrogen forms a permanent, ongoing process, with hydrogen being removed from the tank in gaseous condition and fed to the fuel mixing and supply system. Precisely for this reason liquid hydrogen is evaporated in a specific, controlled process within the tan, building up a gas “cushion” under defined pressure.

Gaseous hydrogen extracted from the tank has to be warmed up for the subsequent fuel mixing process, using heat from the engine’s coolant circuit for this purpose. This heat is generated by a system of two interacting heat exchangers, the heat exchanger in the so-called secondary system capsule (SSC) receiving its heat from the engine’s cooling circuit and delivering this heat, first, via the second heat exchanger to the hydrogen tank and, second, to the hydrogen itself warmed up for the subsequent fuel mixing process.

Filling the tank in a process standardised worldwide

After manually connecting the tank pump coupling, the hydrogen tank is filled up automatically without any intervention on the part of the driver. So all the driver has to do is open the tank filler flap by pressing a button in the cockpit. Then he connects the tank filling coupling to the fuel tank cap simply by interlinking the two components with one another, the subsequent process of filling up the tank being completed automatically in about eight minutes.

BMW’s engineers have developed a standardised tank coupling for all liquid hydrogen filling stations the world over. This tank filler has been engineered in close cooperation between car makers, fuel supply companies, and the German company Linde with the technical know-how required for the generation, distribution and use of hydrogen.

The European automotive industry was represented in this joint development by the BMW Group, ensuring a worldwide technical standard for liquid hydrogen filling systems.

Gasoline is filled into BMW Hydrogen 7 in the same way as on a conventional car, and the twelve-cylinder power unit is configured for premium plus fuel.

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