Liquid hydrogen tested as auto fuel

A recent demonstration project had been evaluated for a hydrogen-fueled vehicle by the U.S. Department of Energy Division. This demonstration will be applicable to other means of transportation such as trucks and trains.

Several participating manufacturers, in an effort to study the problems involved in fueling automobiles with liquid hydrogen, to demonstrate a vehicle of conventional appearance, performance operating on liquid hydrogen, and to demonstrate a liquid refueling station that can be operated by personnel with minimal training. Safety, economic and energy assessments will also be considered.

As a result, they use a 1979 Buick Century fourdoor sedan with 3.8 liters displacement turbocharged V-6 engine. This vehicle provided a good compromise on trunk space for installation of the DFVLR tank, passenger accessibility for demonstration, engine compartment space for versatility in selection of substitute engines, available engine sizes, efficiency and suitability for modification of hydrogen operation.The DFVLR tank and installation was made by Billings Energy Company.

Some goals of the vehicle performance are to provide a minimum fuel economy of 54km/4.5 liters of liquid hydrogen over a 259 km range before refueling.

In regards to safety, the liquid hydrogen tank is equipped with pressure relief valves that are activated at 450 KPA, should a loss of insulating vacuum in the hydrogen tank begin to boil off liquid hydrogen.

As far as the economics are concerned, the cost of the liquid hydrogen as delivered to the automobile is $9.48/1.0551×10^9 Joules, which is equivalent to gasoline at $0.25/liter, however, the bulk rate is $0.21/liter.

The estimated cost for a hydrogen engine will add about $300 and the liquid hydrogen tank will add another $250-$900 to the cost of the vehicle.

The energy assessments for liquid hydrogen – energy liquefaction – losses in transfer and storage. For compressed gaseous hydrogen energy of compression, and high tank weight, which decreases vehicle efficiency by about 1.2%/kg. And for metal hydrides – energy of dissociation (use waste engine heat).

The operation of this vehicle on liquid hydrogen provides an accumulation of operating experiences and demonstrates to the public that liquid hydrogen is a practical alternative fuel for transportation.

In the experimental states of the project, improvements such as the onboard storage Dewar can be built to provide significantly lower blowoff rate and can extend holding time without loss of hydrogen.

Improve the engine performance with increased power and efficiency, less NO X0020 emissions and no back flashing.

The overall efficiency of the vehicle could be increased if the refrigeration or expansion capability of the liquid hydrogen were utilized.

The refueling operation could be completed, automated an improved in several areas. Install a suitable mass flowmeter for determining quantity of hydrogen transferred to the fuel tank, a system that will minimize liquid hydrogen loss from cooling warm transfer lines and a system that will prevent contamination and ice build-up in the transfer lines because of the lines being open to the atmosphere while still cold.

PAUL JONES

ASME Member since 1980

Coaldale

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