Chassis Dynamometer Evaluation of On-board Exhaust Emission Measurement System Performance in SI Car under Transient Operating Conditions 2008-01-1826
A commercial on-board exhaust emissions measurement system, the Horiba OBS-1300, was evaluated in a series of chassis dynamometer test trails. A EURO 1 (petrol) SI passenger car, operated under normal and rich combustion conditions, and a combination of static and transient sampling provided a wide range of measurement conditions for the evaluation exercise. The chassis dynamometer facility incorporated an ‘industry standard’ measurement system comprising MEXA-7400 gas analyzer and CVS bag sampling system which were used as ‘benchmarks’ for the evaluation of both OBS-1300 component (exhaust flow meter and species analyzer) measurements and ‘daughter’ emission measurements for regulated gas-phase species (CO, CO2, HC and NOx).
Trials demonstrated very good to reasonable agreement for exhaust flow and CO, CO2 and HC concentration measurements during static (R2 ≈ 0.97, 0.99, 0.99 and 0.97, respectively) and transient (R2 ≈ 0.88, 0.96, 0.95 and 0.86, respectively) testing. Transient emission measurements of CO, CO2 and HC were generally consistent with ‘parent’ exhaust and species analyzer measurements (R2 ≈ 0.89, 0.89 and 0.81, respectively). Minor issues associated with exhaust flow measurement error at engine ‘tick-over’/idle and HC measurement agreement under different engine operating conditions are discussed. However, in general, the OBS-1300 provided a reliable measure of CO, CO2 and HC exhaust emissions under all conditions investigated.
By contrast, the OBS NOx sensor cross-sensitivity to NH3 hindered the reliability of NOx data, especially under rich engine operation conditions.
Citation: Ropkins, K., Tate, J., Li, H., Andrews, G. et al., "Chassis Dynamometer Evaluation of On-board Exhaust Emission Measurement System Performance in SI Car under Transient Operating Conditions," SAE Technical Paper 2008-01-1826, 2008, https://doi.org/10.4271/2008-01-1826. Download Citation
Karl Ropkins, James E. Tate, Hu Li, Gordon E. Andrews, Gary Hawley, Margaret C. Bell
The University of Leeds, The University of Bath, Newcastle University
2008 SAE International Powertrains, Fuels and Lubricants Congress