Requirements for Fuel Consumption Measurement for Emissions Regulations US07/10 and for Euro 4/5Design Criteria and Layout of the Fuel Measurement Systems

New heavy-duty diesel engine emission test regulations require even tougher emission limits verified with steady-state as well as transient test procedures, which are becoming increasingly important.

The target of this paper is to describe the requirements and tasks for the fuel consumption measurement system and to discuss critical parameters which are essential for the layout of the fuel measurement system.

The resulting fuel measurement system will be described and the performance ability will be demonstrated by measurement results and application examples.

High absolute measurement accuracy of the fuel mass flow sensor, high fuel temperature control accuracy, appropriate fuel pressure control and fast time response of the complete fuel measurement system are all crucial factors needed to achieve repeatable specific fuel consumption values within 1 g/kWh and an overall time response of less than 300 ms. This allows the determination of the on-line exhaust mass flow required for exhaust emission modal analysis and for emission certification with partial flow dilution according to Euro 4/5 without using a CVS system.