Analysis of the EU7 Emission Limits; Exhaust System Solutions to Meet the Requirements

Authors

R. Brück, K. Konieczny, L. Pace, Emitec Technologies GmbH, Lohmar:

Year

2023

Print Info

Production/Publication ÖVK

Summary

Parallel to the discussion regarding the future of internal combustion engines in Europe, the EU Commission proposal on EU7/VII passenger car and truck emissions legislation was announced on 10^th of November 2022.

In addition to the limit values, the definition of "normal" and "extended" driving conditions will be of significant importance for the future catalytic converter system design. This includes, apart from the minimum driving distance for real driving profiles, the length of the idling phase before the first drive off, the driving dynamics and thus the allowed average engine power during cold start. In addition, in hybrid vehicles, purely electric driving up to the motorway entrance with subsequent rapid start-up of the combustion engine on the acceleration lane is conceivable. Accordingly, even an acceleration phase immediately after engine cranking without prior idle phase must be considered.

Superimposed with extended ambient conditions, such as a 0°C ambient temperature under "normal" driving conditions, this results in a completely new requirement profile for the powertrains and exhaust gas aftertreatment.

CARB and EPA are also considering so called "rapid acceleration cycles" and proposing to reduce the idle time in the American FTP test from 20 seconds down to 5 seconds.

On the basis of and compared to the published EU7 proposal, extensive tests were carried out. This includes both the predefined "normal" and "extended" driving conditions, driving without idle time (different average engine power during cold start), acceleration based on the rapid acceleration tests, with and without torque limitation as well as trailer operation on an air-conditioned engine test bench. The results are shown and discussed in relation to the legislative proposal and targeted catalyst systems are presented.

ISBN

978-3-9504969-2-5