Imapct of the Ambient Tempreture on Gas Turbine Efficiency 1

[amrh]

Dear All,
I would like to know if there is studies regarding the Imapct of the Ambient Tempreture on Gas Turbine Efficiency.

I would appreciate any information on that matter.

Thank you a lot

--Amr Salah

 

[steve58]

amrh,

I'm not sure what, in particular, you are looking for. In general, ambient temperature (aka compressor inlet temperature, or CIT) has a definite impact on gas turbine performance based on the fundamental principals of thermodynamics and the ideal gas law (pv=RT). The gas turbine is generally designed for optimum performance (efficiency) at a defined set of inlet conditions at base load. Deviation from these defined inlet conditions will have an impact on performance. The quantitative effects on gas turbine performance as a result of varying CITs are unique for each engine model (the reason is that the compressor volume flow rate is changed due to Mach number effects and the cycle pressure ratio is changed because turbine inlet temperature (TIT) is normally held constant at base load conditions). If you are looking for an in-depth technical reference, try "Gas Turbine Performance" by Walsh and Fletcher.

Do you have a specific gas turbine for which you would like to have correction curve for ambient temperature? If so, this is generally available from the gas turbine manufacturer.

 

[poetix99]

The ambient humidity can have a significant effect upon GT efficiency as well (as you will learn from the book referenced by Steve58).

 

[gtsim]

The ideal thermal efficiency of a simple cycle gas turbine is independent of ambient temperature and only dependent on the compressor pressure ratio – for a given gas. When imperfections (i.e. irreversibilities) are present in the compression and expansion processes then the thermal efficiency is dependent on the ambient temperature and also the turbine entry temperature (TET or maximum cycle temperature). Another good book that discusses this is Gas Turbine Theory by Cohen, Rogers and Saravanamuttoo. We have also developed simulators, which you can download and evaluated it. You can investigate the impact of change ambient conditions such as ambient temperature on performance. A free e-book on gas turbine performance and operation is also included. The web site is

http://www.gpal.co.uk.

 

[abeltio]

try the following link.

http://www.gepower.com/prod_serv/products/tech_docs/en/downloads/ger3567h.pdf

ger3567h has the correction curves for gt performance, fig 9, 10 and 11.

these curves are actually used in practice to correct the unit's output to ISO conditions.

HTH


saludos.
a.