Gas turbine performance vs ambient temperature question 1 1

[HRTesla]

Dear colleagues,

I need to conceive a good explanation about the effect of ambient temperature on a gas turbine performance, but what I'm still not able to explain clearly is the impact of a lower airflow on the compression ratio. When the ambient temperature is lower, the airflow @ compressor intake is lower, then the compression ratio is lower as well. Why? Many thanks in advance for your explanation. If I'm in the wrong forum, do not hesitate to advice me where to write this question again.

Kind regards,

HR

 

[IRstuff]

Is this for school?

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[HRTesla]

Well...some kind of training to operators and I'm appointed to give it, and I wanna be ready at 100%

 

[rmw]

Your premise is not correct. Your compressor is a volume machine. When the ambient temp is lower, the air is more dense and hence you get more massflow for a given volumetric flow rate. A gas turbine is a heat engine that depends on mass flow of air through it. It is the lb/hr of air going through the machine that is heated by the fuel and which then in turn drives the turbine(s). More mass flow, more power.

That is why turbines lose capacity in hot weather, they just can't "pump" as much air through them to add fuel to to make power with.

rmw

 

[HRTesla]

Thanks for your reply rmw I agree with you and your explanation sounds good,nevertheless mine is based on a text written in a book which links the compressor ratio with the airflow. I took contact yesterday with the author who replied, but I'll have to analyze his answer today. It's my next action more information in the next hours. Thanks again!