BMW Sets Speed Records with Hydrogen fuelled V12

The simple solution to this problem is to leave out this mixture "window" altogether, since it is not required for running the engine. Hence, the fast management system controlling the BMW hydrogen engine skips this operating range completely, thus avoiding NOx emissions in the process.

As a result, the H2R Record Car is just as powerful as a conventional gasoline-engine car, while at the same time its emissions are limited, for all practical purposes, to nothing but steam.

The fuel system featured in the BMW H2R Record Car is based on a proven series development concept. Fuel is filled into the tank of the H2R prototype at a mobile hydrogen filling station through a manual tank coupling. The vacuum-insulated, double-walled tank has a capacity of more than 11 kilos of liquid hydrogen and is fitted next to the driver's seat. A total of three valves ensures optimum safety, the operating valve on the tank opening at a pressure of 4.5 bar.

Two additional safety valves rule out any dangerous consequences of possible leaks in the jacket around the tank serving to keep the hydrogen at the low temperature required, opening up as soon as pressure within the tank exceeds the limit of 5 bar. This double-redundant safety system guarantees optimum safety at all times, ensuring that the hydrogen tank will not burst as a result of excess pressure.

Gas pressure builds up in the fuel supply system simply because of the rising temperature of the cryogenic, liquid hydrogen in the tank and is kept at an operating pressure of approximately 3 bar by a tank pressure controller. Then the coolant running within the 12 cylinder power unit warms up the hydrogen gas in a heat exchanger to ambient temperature.

Additional valves monitor the pressure of gas in the fuel pipes leading to the engine: Cold low-temperature valves inside the tank control the removal of hydrogen from the tank itself. Should any of the pre-flow pipes develop a leak, with supply pressure dropping below 0.4 bar, the fuel supply valves close automatically, disconnecting and sealing the tank off from its surroundings.

The supply pipe can also be interrupted manually by an interruptor tap. To maintain optimum supply pressure on the injection valves at all times - especially as this pressure may vary as a function of driving conditions - engine management reduces pressure in the supply pipe to approximately 1.2 bar by means of a control valve fitted specifically for this purpose.

This comprehensive safety system featured in the H2R Record Car is supervised additionally by a telemetric system of the same type as in Formula 1. Four hydrogen sensors fitted at neuralgic points - for example in the tank itself and around the tank coupling - recognise any leakage immediately and inform the driver accordingly.

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