Saturated VapourPressure of Steam above Critical Temperature

[Sorade]

Hello all,

I am not sure my question will totally make sense for those of you who now this topic well but as I am new to it I hope I can be forgiven.

My problem is to work out how much water will condensate as a stream of moist air is expanded through a turbine.

So far I was using Antoine's Equation (https://en.wikipedia.org/wiki/Antoine_equation) to determine how much water could be held in my gas stream at the turbine outlet Pressure and Temperature.

I however have cases where my outlet Temperature is greater than 374 degrees C, and my code returns an error. I have been looking for equations or tables providing the saturated vapour pressure for temperatures above 374 C but I couldn't find anything.

Any help or comment would be welcome.

 

[anorlunda]

I used to do that graphically with a printed Mollier Chart, the ASME Steam Tables, and a slide rule. Slide rules are gone, but the steam properties are still valid.https://en.m.wikipedia.org/wiki/Enthalpy–entropy_chart

https://www.nist.gov/publications/asme-international-steam-tables-industrial-use-third-edition

 

[Chestermiller]

There is no such thing as saturated vapor pressure above the critical temperature. No amount of pressure can cause a substance to condense if the temperature exceeds the critical temperature.