Fuel dilution measurement

On-line measurement of fuel dilution and evaporation in I.C. engines

EN

Fuel dilution measurement is of particular interest in light of new environmental regulations imposed on today's passenger car and heavy duty engines. Our methodology is based on lubricant labelling using a new radiotracer compound, which is representative of lubricant.

Measurement principle

As first step, a radiotracer compound is mixed to the lubricant. During the engine operation, oil continuously circulates into a measuring chamber where the signal (gamma-rays) emitted by the radiotracer is monitored. This signal is representative of the dilution process. Temperature / density effects are automatically corrected.

Fuel dilution measurement principle

The methodology can be applied to gasoline, diesel and bio-fuel engines to optimize cold start procedures, for the development of post-injection strategies and of evaporation cycles.

D-Lube offers significant advantages over other methods, including:

  • On-line / Real-time results: Fuel dilution is continuously monitored during engine operation, at a rate of 1 measurement per minute.
  • Short Test Durations: Dilution rates are accurately measured within short runs from several min. to hours, depending on dilution rates.
  • High sensitivity: Sensitivity is of 0.05% per hour (in terms of volumic dilution rate).
  • No change in oil properties: Less than 100 µl of tracer is added to the engine oil pan. Moreover, the tracer is of the same nature as base oil. 
  • Easy to install: Oil is directly sampled from the sump at a rate of ~1 litre per min. 2 hoses are easily connected between the engine oil sump and D-Lube equipment.
  • Applicable on test beds and on vehicles: Standard equipment is dedicated to test bench applications. A compact version is available for on-board installation on passenger cars and HD vehicles.

The graph hereunder shows typical results obtained during successive dilution and evaporation phases performed on a passenger car diesel engine. Oil temperature (red signal) and fuel content in oil (blue signal, in %) are displayed on-line.

Dilution/Evaporation phases on turbo diesel engine equiped with DPF

D-Lube equipment significantly reduces the time needed to optimize fuel injection strategies on I.C. engines.