CO2 input limitations or inproper table link?

[CptUran]

Hi MadsKirkFoged,

I've stumbled across some weird results during my mixtures calculations. Upon further examinations it turns out that CO2 part wasn't updating it's status at all. It happens at low pressures and low temperatures (relatively). I was wondering if this has something to do with input limits or is there some error in CO2 table, because CoolProp Online ans NIST Database seems to have proper results in this range. Below is a simple code I wrote for this test. (Enthalpy passed as an input in last line is proper enthalpy at 1 bar and 273 K according to CoolProp Online).

using SharpFluids;
using EngineeringUnits;
using EngineeringUnits.Units;


double press = 101000;
double temp = 273;
Fluid CO2 = new Fluid(FluidList.CO2);

CO2.UpdatePT(Pressure.FromPascals(press), Temperature.FromKelvins(temp));
Console.WriteLine(CO2.Density.As(DensityUnit.KilogramPerCubicMeter));
CO2.UpdatePT(Pressure.FromBars(5), Temperature.FromDegreesCelsius(150));
Console.WriteLine(CO2.Density.As(DensityUnit.KilogramPerCubicMeter));
CO2.UpdatePT(Pressure.FromBars(10), Temperature.FromDegreesCelsius(300));
Console.WriteLine(CO2.Density.As(DensityUnit.KilogramPerCubicMeter));
CO2.UpdatePH(Pressure.FromBars(1), Enthalpy.FromKilojoulePerKilogram(484.749));
Console.WriteLine(CO2.Density.As(DensityUnit.KilogramPerCubicMeter));

And here are the results:

0
0
9,26798114913052
9,26798114913052

I'm not sure what to do with this. Thank you for any help :)

Best Regards

[MadsKirkFoged]

Co2 turns into solid at ~5bar - I believe that's the reason for your result.

If you run this code you can see its limits:

Console.WriteLine(CO2.LimitPressureMin.ToUnit(PressureUnit.Bar)); //5.18 bar
Console.WriteLine(CO2.LimitTemperatureMin.ToUnit(TemperatureUnit.DegreeCelsius)); //-56.56 °C

[CptUran]

Thank you for your answer! Is CO2 in this only limited to solid? Is there a way to get results for it's gaseous state? E.g. CO2 at atmospheric pressure?

[MadsKirkFoged]

CO2 at atmospheric pressure turns into dry ice.

I think you'll need to tell me more about what you seek

[CptUran]

I am trying to model thermodynamic states of gasses in a gas turbine, so normal air -> compression -> adding fuel -> combustion -> expansion. Now if i want to use "Air" as provided in CoolProp Lib everything works, however working with exhaust fumes where CO2 concentration is much higher is toublesome because of this limitations. Is there a way to work around this?