Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


Do altitude affect emissions on a Heavy-Duty Diesel Engine?

Do altitude affect emissions on a Heavy-Duty Diesel Engine?

Do altitude affect emissions on a Heavy-Duty Diesel Engine?

I understand that a genset should be derated according to the meters above sea level, however, what happens to emissions?. If the motor burns X amount of fuel, that fuel must represent the electrical energy produces. Derating is due mostly by engine temperature -among other factors- (correct me if I'm wrong).

RE: Do altitude affect emissions on a Heavy-Duty Diesel Engine?

De-rating is because of thinner air, so less air to mix fuel with. So less fuel, so less power. Because the fuel is reduced, power is reduced, and even emissions should be reduced because less fuel is being burned. (modern engine and fuel delivery assumed which provides for altitude compensation)

If you're talking about an older non-altitude compensated engine then yes, less power for the same reason, but because the fuel isn't being reduced to keep the mixture dialed in you will get more emissions. This, because the mixture is too rich and incompletely burned and worse the governor will advance in an attempt to still provide the power needed making it all worse yet.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Do altitude affect emissions on a Heavy-Duty Diesel Engine?

Traditionally, de-rating was to keep turbocharger RPM under control. Less air = higher turbo RPM to produce the same level of boost. This was even the case before wastegates became standard.

There must be some effect on radiator cooling, also. If the alternator itself has a max altitude rating, the radiator must suffer the same effect.

Theoretically, the emissions should not change much, if the turbocharger is able to supply the same amount (lbs/hour) of air.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


eBook - Rethink Your PLM
A lot has changed since the 90s. You don't surf the Web using dial-up anymore, so why are you still using a legacy PLM solution that's blocking your ability to innovate? To develop and launch products today, you need a flexible, cloud-based PLM, not a solution that's stuck in the past. Download Now
White Paper - Using Virtualization for IVI and AUTOSAR Consolidation on an ECU
Current approaches used to tackle the complexities of a vehicle’s electrical and electronics (E/E) architecture are both cost prohibitive and lacking in performance. Utilizing virtualization in automotive software architecture provides a better approach. This can be achieved by encapsulating different heterogeneous automotive platforms inside virtual machines running on the same hardware. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close