6 replies to this topic

[Cracktheskye]

Hello,

I need some help in this:

 

 

How do I calculate the efficiency of this turbine (HPP-HP section)?

 

Thank you

[Art Montemayor]

 

 

The basic definition of an expansion turbine efficiency is: (the actual work done by the turbine / the calculated work done by the turbine) (100) .

 

One can calculate the work expected out of the turbine….. BUT do you KNOW the actual work done by the turbine?  If you do, you aren’t telling us.

 

[Cracktheskye]

Thanks for your reply and sorry for my poor english.

I don't know the work done by the turbine. My problem is exactly this.The information I posted here is just what I got to solve this problem.

[Bobby Strain]

You use steam properties, pressures, and temperatures to calculate efficiency of the HHP-HP section. A Mollier chart is most useful for this purpose.

 

Bobby

Edited by Bobby Strain, 31 January 2014 - 03:03 PM.

[Cracktheskye]

In Mollier chart I will get the theoretical enthalpy, right? Where can I find the real enthalpy in this case?

 

Thanks,

[PingPong]

Also from the h-s diagram (Mollier diagram). You know P₁, T₁, P₂ and T₂ so ....... piece of cake.

 

 

 

http://www.ohio.edu/.../Chapter6a.html

 

Edited by PingPong, 31 January 2014 - 04:32 PM.

[Art Montemayor]

Crack:

 

I hope that by now you've realized that there is no way you can know the REAL, ACTUAL enthalpy of the outlet enthalpy unless you're the manufacturer of the turbine and you've run exhaustive pilot tests with your turbine to discover the resulting efficiency when you operate your turbine.

 

How else, logically, could you ever know the efficiency of the turbine?  Turbine efficiencies are not calculated with analytical equations; they are the result of the actual turbine's operation - and that depends on how good the manufacturer is at making turbines.  Does that make horse sense?

 

Some turbines are more efficient than others.