Characterising heavy-duty fuel systems: a critique of industry practice and challenges

Abstract

Fuel system components must perform optimally to ensure the maximum fuel economy and the minimum emissions. The key to optimised performance is effective characterisation of the system in the factory. This paper describes methods for discerning the features of a fuel injection system’s performance during built-unit testing. First, a background is given, highlighting the impact of environmental legislation. Next, specifications for a modern fuel system and key functionality characteristics are identified, and a brief overview of the alternative system configurations offered. The injector function is then discussed, with the importance of the key subcomponents being explained. Methods of testing and characterising the fuel injector performance in use are then described. Finally, there is discussion on the future of fuel system testing, and how developing challenges such as measuring the injection timing and the fuelling quantity in high-pressure, high-temperature and high-vibration environments might be overcome with better instruments and novel testing strategies including a paradigm shift away from steady-state testing to fully dynamic system testing.