EBSILON®Professional Online Documentation
EBSILON®Professional supports these material value tables or libraries resp. for water and steam:
Which table is be used for streams of type water or steam can be set in the model settings under Simulation / Substance Properties for the entire model (EbsScript: @calcoptions.sim.watersteamtable):
For new models, the IF-97 (SBTL) or IF97 should be used. Both correspond to the current standard.
The splines version (SBTL) additionally allows shorter calculation times by using splines instead of polynomials.
The range of validity extends from 0 to 800 °C and from 0.01 to 1000 bar for both tables, the IF-97 additionally covers the range from 800 to 2000 °C for pressures from 0.01 to 100 bar.
The IFC-67 is only used to reproduce the results of models created with older EBSILON versions.
The LibIce and Refprop waters can only be used with the two-phase fluid (liquid or gaseous) and universal fluid stream types.
NASA water can be used with the stream types NASA and universal fluid.
TREND water and Coolprop water can be used with the Universal fluid stream type.
The LibIce, Refprop water, Coolprop water and TREND water can only be used with the two-phase fluid (liquid or gaseous) and universal fluid stream types.
NASA water can be used with the stream types NASA, two-phase fluid (liquid or gaseous) and universal fluid. Assignment to streams is done via component 1 (or also component 33).
LibIce contains the physical properties functions of water for all three phases incl. all two-phase ranges for temperatures from -223.15 °C to 350 °C and pressures from 1.935*10-45 to 1000 bar. LibIce is available in the universal fluid and in the User-2Phase-fluid. Note: Water and steam streams will not automatically switch to LibIce if you are in the corresponding range of state. The reason is that in the models usually represented with Ebsilon this is not desired anyway, but convergence problems can occur in the event of an automatic switchover if temporarily values are assumed in the ice range in the course of the iteration. In particular, already the usual starting point of P=0.01 bar, H=10^-6 is barely in the two-phase range water/ice. For the two-phase fluid, the entry “Water” has been expanded to “Water (3 phases)”. This allows modeling water in the entire range from -223.15 °C to 2,000°C. For temperatures up to 350°C, LibIce is activated, above this LibIf97.
All available functions for all material tables: see Material-Table- Dialog ---> Functions
The water/steam tables contain, among others, the following functions for the water or steam range (outside the wet steam range):
|
h = f(p, t) |
(1001) |
Specific enthalpy |
|
s = f(p, t) |
(1002) |
Specific entropy |
|
v = f(p, t) |
(1013) |
Specific volume |
|
cp= f(p, t) |
(1017) |
Specific isobaric heat capacity |
|
cv= f(p. t) |
(1058) |
Specific isochoric heat capacity |
|
rho=f(p, t) |
(1060) |
Density |
|
w = f(p, t) |
(1062) |
Isentropic sound velocity |
|
kappa=f(p, t) |
(1064) |
Isentropic exponent |
|
nue=f(p, t) |
(1068) |
Kinematic viscosity |
|
eta=f(p, t) |
(1070) |
Dynamic viscosity |
The following functions are available for the entire region including the wet-steam area:
|
t = f(p, h) |
(1003) |
|
|
h = f(p, s) |
(1007) |
|
|
s = f(p, h) |
(1008) |
|
|
t = f(p, s) |
(1004) |
|
|
x = f(p, h) |
(1009) |
|
|
cp = f(p, h) |
(1012) |
|
|
v = f(p, h) |
(1014) |
|
|
eta = f(p, h) |
(1029) |
Dynamic viscosity |
|
lambda = f(p, h) |
(1030) |
Heat conductivity |
The following are available on the saturation line:
|
t = f(p) |
(1005) |
Saturation temperature |
|
p = f(t) |
(1006) |
Saturation pressure |
|
p = f(h') |
(1015) |
Pressure for the enthalpy of the boiling liquid |
|
p = f(s") |
(1016) |
Pressure for the entropy of the saturated steam |
|
sigma = f(p) |
(1066) |
Surface tension at the phase boundary at the pressure p |
|
sigma = f(t) |
(1067) |
Surface tension at the phase boundary at the temperature t |
Moreover, the water/steam-table also contains the following functions for saturated water and saturated steam:
|
h' = f(p) |
(1010) |
Enthalpy of the boiling liquid at the pressure p |
|
h" = f(p) |
(1011) |
Enthalpy of the saturated steam at the pressure p |
|
h' = f(t) |
(1056) |
Enthalpy of the boiling liquid at the temperature t |
|
h" = f(t) |
(1057) |
Enthalpy of the saturated steam at the temperature t |
For the construction of the background lines in the diagrams there are some additional functions. These functions are not unique in the whole region and may cause numerical problems. Therefore, they should only be used carefully.
|
h = f(x, s) |
(1024) |
|
h = f(t, s) |
(1025) |
|
x = f(p, s) |
(1026) |
|
p = f(x, s) |
(1027) |
|
p = f(t, s) |
(1028) |
|
h = f(p, x) |
(1031) |
|
t = f(h, s) |
(1035) |
|
t = f(x, s) |
(1036) |
|
p = f(s, h) |
(1037) |
|
s = f(t, h) |
(1040) |
|
s = f(t, x) |
(1041) |
The numbers given in brackets refer to the function numbers, which are to be used when calling the function from EbsScript.