Safe Practices and Procedures for High Voltage and Hydrogen in Ford's H2RV 2004-01-0059

In recent times, the development of alternate-fuel vehicles, including those fueled by hydrogen, has become relatively common. While there are potential safety related issues with any combustible fuel, these have been resolved over the last 100+ years. The comfort level with gasoline fuel has resulted from the widespread application of simple safety procedures followed at every stage of gasoline refinement and handling. It is important to have analogous procedures for handling hydrogen-fueled vehicles safely and with confidence.

The characteristics of hydrogen, including: a) wide flammability range, b) very low ignition energy, c) odorless and difficult to detect, d) high diffusion rate, e) high buoyancy, f) invisible flame, etc., bolster the need for safe practices and procedures. In addition, hydrogen is commonly stored in a highly compressed state (around 5000 PSI or higher), which makes the system vulnerable to leaks and may result in the formation of a combustible mixture of hydrogen and air. The presence of an electric drivetrain, high-energy batteries and many of the electrical subsystems in a hybrid electric vehicle makes it potentially risky with conventional electrical / electronic items. As with any vehicle using a combustible fuel, the possibility of having both a combustible fuel mixture and an ignition source could lead to a potential for fire.

This paper presents the procedures and practices followed with a high-voltage, hydrogen-fueled vehicle during vehicle development, transportation, maintenance, and storage, including actions taken in the event of an emergency situation.