Use for PR, SAFTVRMie, PCSAFT for Compressors

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Hi am was testing Clapeyron for a polytropic compression. My first check was to use COOLPROP with PR and HEOS options. These agreed. Then using the same test I usewd Clapeyron GERG2008 this agreed with COOLPROP.

Then simply using the same code and changed to PR, SAFTVRMie, and PCSAFT as test all disagreed with GERG2008. But the agee with each other.

The problem is CO2 + Ethane at 1 bar and 30 mdeg C compressed polytropically to 3 bar with efficiency 84%.

HYSYS for PR gives 124 deg C for the discharge temperature, COOLPROP does the same. Clapeyron for GERG2008 gives 124 detg C. For PR, SAFTVRMie, and PCSAFT Clapeyron gives around 232 deg C.

The densities all look correct the issue appears to be the Enthalpy. Only GERG2008 calculates the correct enthalpy change. Is there a difference between the Enthalpy calculation for GERG2008 and PR, SAFTVRMie, and PCSAFT.

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Hello, Spotted the error. By default BasicIdeal is used. This is not used for GERG2008. To get the correct Enthalpy you need an Ideal model with Ideal_Cp(T). I used AlyLeeIdeal and all works OK.