ViswaLab in its latest technical update gives a detailed insight into The Engine Friendliness Number (EFN) is a unique benchmark of fuel quality that measures the engine friendliness of the individual supply of bunker fuel.
Software incorporating this approach provides the bunker fuel user the ultimate evaluation tool for bunker suppliers.
Over a period of time, EFN will provide a pattern for distinguishing good fuels, bad fuels, or average fuels. The EFN pattern would identify suppliers of competent quality fuel and would eventually be able to predict a correlation between maintenance problems and EFN pattern.
Analysis of parametric value
Each parametric value of analyzed fuel is evaluated for its position in the range of acceptable values and given a score.
A weightage factor is superimposed on this score depending upon the potential of that test parameter to cause damage. All these scores are then aggregated and placed on a scale of 1 to 100.
How is it calculated?
For heavy fuel oil (HFO) samples, over hundreds of thousands of samples tested, it has been noted that when EFN is greater than 60, there are generally no fuel-related problems and when EFN is below 40, problems can be expected.
Please note that EFN calculation does not take into account the presence of any contaminants in the fuel.
Different formula for different VLSFO composition
Since VLSFO compositions and properties are anticipated to vary significantly from region to region and from port to port, we have developed a new formula to calculate the EFN.
For very low sulfur fuel oil (VLSFO) samples, over hundreds of thousands of samples tested, it has been noted that when EFN is greater than 55*, there is generally no fuel-related problems and when EFN is below 35*, problems can be expected.
Please note that EFN calculation does not consider the presence of any contaminants in the fuel.
Impact of parameters that affect engine performance
In general, we are considering the impact of all parameters with different weightage factors (such as catfine, sediment content, Micro carbon residue, etc.) that affect engine performance.
Also, we are developing a new algorithm to calculate the EFN for distillate fuel (DEFN) which is going to be released in the near future. The weightage factor for each parameter is based on the impact on engine and performance.
Criteria for evaluating the fuel quality based on EFN:
Fuels HFO VLSFO Below average <40 35
Average 40-60 35-55 Good fuel >60 >55
Benchmark presented for VLSFOs
As the number of new fuels (VLSFOs) keeps increasing, some of their assessment will change. When the fuel is newly introduced, the suppliers try to keep it very clean, but after some time when the user gets used to it, we will start seeing contamination and we might change the benchmark presented for VLSFOs.
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Source: Viswa Group