An Experimental Study of NOx Emissions for the Development of an Emission Analysis Tool

A purpose-built diesel engine test bed with specially developed software has been used to acquire NO\dx emission data in conjunction with additional engine parameter data under selected operating conditions. With the ability to remotely control both the engine speed and the torque to which it is subjected, tests were taken under steady-state conditions and over a substantial proportion of the engine's overall operating range. For NO\dx control purposes diesel engines are normally fitted with Exhaust Gas Recirculation (EGR) as standard. Tests were carried out both in this default factory setup and without any NO\dx control technologies, i.e., including the disconnection of the standard EGR.

The variation of the NO\dx emissions has been mapped across the corresponding speed and torque conditions. Additional data analysis techniques, which include multivariate analysis, have facilitated the identification of relationships both between individual parameters and the NO\dx emissions; and between combinations of the parameters and the NO\dx emissions.