Transient Efficiency, Performance, and Emissions Analysis of a Hydrogen Internal Combustion Engine Pick-up Truck 2006-01-3430

Hydrogen is considered one of the most promising future energy carriers. There are several challenges that must be overcome in order to establishing a “hydrogen economy”, including the development of a practical, efficient, and cost-effective power conversion device. Using hydrogen as a fuel for internal combustion engines is a huge step toward developing a large-scale hydrogen infrastructure.

This paper summarizes the testing of a hydrogen powered pick-up truck on a chassis dynamometer. The vehicle is powered by a port-injected 8-cylinder engine with an integrated supercharger and intercooler. The 4-wheel drive chassis dynamometer is equipped with a hydrogen delivery, metering and safety system as well as hydrogen specific instrumentation. This instrumentation includes numerous sensors, includes a wide-band lambda sensor and an exhaust gas hydrogen analyzer. This analyzer quantifies the amount of unburned hydrogen in the exhaust indicating the completeness of the combustion. Transient analysis of efficiency and emissions trends in dynamic engine behavior is possible since all the data is recorded at a frequency of 10 Hz. The standard emissions bench provides information on the transient emissions behavior, for hydrogen engines, NO_x values are of specific interest. The vehicle was tested on a variety of drive cycles. The performance was measured by running accelerations at wide open throttle while recording vehicle speed.

The unique properties of hydrogen as a fuel make it possible for the engine to be operated in a wide range of air/fuel ratios. This paper focuses on the influence of the global air/fuel ratio in a constant-phi lean burn operating strategy. Air/fuel ratio is also known to have crucial influence on engine efficiency and emissions. In order to quantitatively define the influence on efficiency and emissions, the same drive cycle was run at different air/fuel ratios. The cycle-based emission and efficiency data is also compared to the performance at each air/fuel ratio.