Simulation of Refrigerant Cycle with COFE

[LiMa]

Hello,

1)I've implemented most data available from the NIST-databank into a PCD-file for R134a (C2H2F4),
but when computing a simple refrigerant cycle there is a problem with the bubble- and dew temperature and pressure.

"warning: Material object error in CalcProp: CalcSinglePhaseProp wrapping failed for v1.1 property pack kaltmittel: property bubblePointTemperature does not exist in request for phase Vapor
warning: Material object error in CalcProp: CalcSinglePhaseProp wrapping failed for v1.1 property pack kaltmittel: property bubblePointPressure does not exist in request for phase Vapor
warning: Material object error in CalcProp: CalcSinglePhaseProp wrapping failed for v1.1 property pack kaltmittel: property dewPointTemperature does not exist in request for phase Vapor
warning: Material object error in CalcProp: CalcSinglePhaseProp wrapping failed for v1.1 property pack kaltmittel: property dewPointPressure does not exist in request for phase Vapor
"
Is that a problem of the PCD-file (missing data) or a matter of adjustment within COFE?

2) Since I'm a student of mechanical engineering, I'm not too familiar with numerical methodes, but there seem to arise some errors in calculation when a cycle is formed via FlowConstraint. The single components do exactly as I learned, but when put together there are vast discrepancies from selfmade calculations and Coolpack. Are there other (better) methodes to form a cycle in COFE?

Thank you in advance

[ed@mo-ed.com]

Youre supercritical!

[jasper]

1) if you are using REFPROP, you may want to look at this

http://amsterchem.com/refpropco.html

the warnings on bubble and dew calculations are because you have configured these properties to be displayed for the vapor phase. COFE does not know anything about which property is doing what, but dew and bubble points are overall properties, attempting to calculate these for other phases will result such an error. Simply turn them off again:

Flowsheet, configure, properties, change the vapor, liquid, vaporliquid options for these properties to No.

It looks like a number of properties are shown for pure components, for vapor, liquid, vaporliquid, including density, enthalpyF, .... This looks like an error in COFE. Typically you want density, enthalpy, ... to be shown for mixture for vapor and liquid, and not at all for vaporliquid (a two-phase combination). Did you configure this or did the property display configuration at some point get mangled? If the latter, can you reproduce it?

2) I cannot comment on this until you tell me what you are comparing with and what are the discrepancies.