Diesel engine fuel consumption

[jpankask]

Our diesel fuel supplier has switched us to ultra-low sulfur diesel fuel, well ahead of the industry expection of next year. We need to recheck our calculations to ensure that our tanks hold enough fuel to meet our technical specifications.

We have from the vendor an old document that list the power specific fuel consumption rate at various ratings of the engine. What I want to do is back calculate their numbers to determine what heating value they used for the original calculations and compare that to the heating value of our new fuel, as determined by the laboratory. I have the various fuel consumption rates at different ratings, the average fuel density and specific gravity. What I cannot find in any of my references is the actual equation that ties everything together. Any suggestions on places to look or an equation itself would be greatly appreciated.

 

[jpankask]

Little more background from my research...

I think what I am really looking at is the brake specific fuel consumption, even thought they don't say it that way. I have found an equation that gets me started...

BSFC = f/[(0.10472*rpm)(0.001*torque)]

This equation is in metric units but all of my data is english. If you have the equation for english units, that would be great. Also, the website I found also uses the heating value to then figure the diesel efficiency but the numbers are also metric.

efficiency = 1/(BSFC*.0119531) 0.0119531 is the heating value of diesel in metric units.

I don't have the efficiencies, only BHP and fuel consumption. Would I be correct in saying that I won't be able to back-calculate the heating value the vendor used with the information I have? Thank you!

 

[TD2K]

The difference in heating values between current diesel (containing up to 500 ppm sulfur) and ultra-low sulfur diesel (up to 15 ppm diesel) is insigificant.

 

[ivymike]

What I want to do is back calculate their numbers to determine what heating value they used for the original calculations and compare that to the heating value of our new fuel, as determined by the laboratory.

uh, what calculations? I would guess that they simply ran the engine a while at each listed power setting, and measured the fuel burned during that time!