6 replies to this topic

[frpe]

for calculating the properties of water and steam I have Prode Properties,

the operating manual does not mention the range of T, P for the IAPWS 1995 model

which is the most accurate available (for water & steam) in PRODE,

Prode allows to calculate a density above 1000 Bar

while for thernal conductivity the range seems more limited,

other properties as isothermal compressibility for liquid state

in some cases return 0 as value (depending from T, P),

does that suggest an error or a limit in the

range of application ?

 

[marchem]

the ranges of application for the different properties calculated by IAPWS 1995 model

are described in IAPWS  documents,

for example thermal conductivity of water (liquid) is calculated up to near the critical point,

in IAPWS 1995 (which is more accurate than IAPWS 1997) formulations are complex

depending from many different properties.

Yes, PRODE PROPERTIES returns 0 when

 

1)  the specified state doesn't exist at specified conditions (for example a liquid above critical temperature),

 

2) the specified conditions (temperature, pressure) are outside the allowable range for that model

 

3) an error of the procedure , in many cases you can get a verbose description of the error calling the proper method or allowing the popup dialog with the description (a typical error is T,P outside applicable range)

[frpe]

thanks marchem,

I have not access to IAPWS 1995,

can you advise about allowed range of temperatures for liquid thermal conductivity ?

[PaoloPemi]

frpe

the IAPWS 95 model for WATER/STEAM properties

included in PRODE PROPERTIES

works from a few degres above melting point up to 647.26 (K)

it is based on IAPWS formulation for thermal conductivity of water

[frpe]

thanks PaoloPemi,

is the allowed range the same for viscosity ?

[PaoloPemi]

yes,

the range is similar,

both properties are calculated starting from reduced density function calculated by IAPWS model.

[frpe]

thanks all

Edited by frpe, 20 August 2014 - 02:52 PM.