(adsbygoogle = window.adsbygoogle || []).push({}); Gas turbine fuel/air ratio & cooling, help please!

Hello Dear Colleagues,

I am doing a gas turbine project and I wonder why we use cooling air instead of decreasing the fuel/air ratio after getting the following results from my gas turbine thermodynamic model.

I have a mechanism in my model which adjust the fuel/air ratio for different pressure ratios and ambient conditions to reach the desired TIT (turbine inlet temp.) of 1755 K.

For selected pressure ratio of 20, I get the following results from the combustion of methane :

Using %80 of the compressor air for cooling and the rest for combustion, I can only reach a maximum TIT of 1360 K at the equivalence ratio 1.019 for stoichiometric combustion of methane. In this case the fuel/air ratio is 0.0584.

Using %50 of the compressor air for cooling and the rest for combustion, I can reach my desired TIT of 1755 K at the equivalence ratio 0.835. In this case the fuel/air ratio is 0.0488, a high value for gas turbines which usually have a fuel/air ratio around 0.02.

When I don't use ant cooling air, I can reach my desired TIT at the equivalence ratio 0.458 and fuel/air ratio of 0.0267.

From these results I come to a conclusion that there is no need for cooling air. If there is a need for that I please ask how I can define the minimum value needed.

I can provide any information needed. Please give me a hand, I am really stuck on this.

Thank you in advance.

Kayhan.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Aerospace Gas turbine fuel/air ratio 7 cooling, help please!

**Physics Forums | Science Articles, Homework Help, Discussion**