Functions to find the current region for given pairs of input variables
Package Regions contains a large number of auxiliary functions which are needed to compute the current region of the IAPWS/IF97 for a given pair of input variables as quickly as possible. The focus of this implementation was on computational efficiency, not on compact code. Many of the function values calculated in these functions could be obtained using the fundamental functions of IAPWS/IF97, but with considerable overhead. If the region of IAPWS/IF97 is known in advance, the input variable mode can be set to the region, then the somewhat costly region checks are omitted. The checking for the phase has to be done outside the region functions because many properties are not differentiable at the region boundary. If the input phase is 2, the output region will be set to 4 immediately.
The main 4 functions in this package are the functions returning the appropriate region for two input variables.
In addition, functions of the boiling and condensation curves compute the specific enthalpy, specific entropy, or density on these curves. The functions for the saturation pressure and temperature are included in the package Basic because they are part of the original IAPWS/IF97 standards document. These functions are also aliased to be used directly from package Water.
All other functions are auxiliary functions called from the region functions to check a specific boundary.
Extends from Modelica.Icons.FunctionsPackage (Icon for packages containing functions).
Name | Description |
---|---|
boundary23ofT | Boundary function for region boundary between regions 2 and 3 (input temperature) |
boundary23ofp | Boundary function for region boundary between regions 2 and 3 (input pressure) |
hlowerofp5 | Explicit lower specific enthalpy limit of region 5 as function of pressure |
hupperofp5 | Explicit upper specific enthalpy limit of region 5 as function of pressure |
slowerofp5 | Explicit lower specific entropy limit of region 5 as function of pressure |
supperofp5 | Explicit upper specific entropy limit of region 5 as function of pressure |
hlowerofp1 | Explicit lower specific enthalpy limit of region 1 as function of pressure |
hupperofp1 | Explicit upper specific enthalpy limit of region 1 as function of pressure (meets region 4 saturation pressure curve at 623.15 K) |
slowerofp1 | Explicit lower specific entropy limit of region 1 as function of pressure |
supperofp1 | Explicit upper specific entropy limit of region 1 as function of pressure (meets region 4 saturation pressure curve at 623.15 K) |
hlowerofp2 | Explicit lower specific enthalpy limit of region 2 as function of pressure (meets region 4 saturation pressure curve at 623.15 K) |
hupperofp2 | Explicit upper specific enthalpy limit of region 2 as function of pressure |
slowerofp2 | Explicit lower specific entropy limit of region 2 as function of pressure (meets region 4 saturation pressure curve at 623.15 K) |
supperofp2 | Explicit upper specific entropy limit of region 2 as function of pressure |
d1n | Density in region 1 as function of p and T |
d2n | Density in region 2 as function of p and T |
dhot1ofp | Density at upper temperature limit of region 1 |
dupper1ofT | Density at upper pressure limit of region 1 |
hl_p_R4b | Explicit approximation of liquid specific enthalpy on the boundary between regions 4 and 3 |
hv_p_R4b | Explicit approximation of vapour specific enthalpy on the boundary between regions 4 and 3 |
sl_p_R4b | Explicit approximation of liquid specific entropy on the boundary between regions 4 and 3 |
sv_p_R4b | Explicit approximation of vapour specific entropy on the boundary between regions 4 and 3 |
rhol_p_R4b | Explicit approximation of liquid density on the boundary between regions 4 and 3 |
rhov_p_R4b | Explicit approximation of vapour density on the boundary between regions 4 and 2 |
boilingcurve_p | Properties on the boiling curve |
dewcurve_p | Properties on the dew curve |
hvl_p | |
hl_p | Liquid specific enthalpy on the boundary between regions 4 and 3 or 1 |
hv_p | Vapour specific enthalpy on the boundary between regions 4 and 3 or 2 |
hvl_p_der | Derivative function for the specific enthalpy along the phase boundary |
rhovl_p | |
rhol_p | Density of saturated water |
rhov_p | Density of saturated vapour |
rhovl_p_der | |
sl_p | Liquid specific entropy on the boundary between regions 4 and 3 or 1 |
sv_p | Vapour specific entropy on the boundary between regions 4 and 3 or 2 |
rhol_T | Density of saturated water |
rhov_T | Density of saturated vapour |
region_ph | Return the current region (valid values: 1,2,3,4,5) in IF97 for given pressure and specific enthalpy |
region_ps | Return the current region (valid values: 1,2,3,4,5) in IF97 for given pressure and specific entropy |
region_pT | Return the current region (valid values: 1,2,3,5) in IF97, given pressure and temperature |
region_dT | Return the current region (valid values: 1,2,3,4,5) in IF97, given density and temperature |
hvl_dp | Derivative function for the specific enthalpy along the phase boundary |
dhl_dp | Derivative of liquid specific enthalpy on the boundary between regions 4 and 3 or 1 w.r.t. pressure |
dhv_dp | Derivative of vapour specific enthalpy on the boundary between regions 4 and 3 or 1 w.r.t. pressure |
drhovl_dp | |
drhol_dp | Derivative of density of saturated water w.r.t. pressure |
drhov_dp | Derivative of density of saturated steam w.r.t. pressure |
Boundary function for region boundary between regions 2 and 3 (input temperature)
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
t | Temperature (K) [K] |
Name | Description |
---|---|
p | Pressure [Pa] |
Boundary function for region boundary between regions 2 and 3 (input pressure)
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
t | Temperature (K) [K] |
Explicit lower specific enthalpy limit of region 5 as function of pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Explicit upper specific enthalpy limit of region 5 as function of pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Explicit lower specific entropy limit of region 5 as function of pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | Specific entropy [J/(kg.K)] |
Explicit upper specific entropy limit of region 5 as function of pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | Specific entropy [J/(kg.K)] |
Explicit lower specific enthalpy limit of region 1 as function of pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Explicit upper specific enthalpy limit of region 1 as function of pressure (meets region 4 saturation pressure curve at 623.15 K)
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Explicit lower specific entropy limit of region 1 as function of pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | Specific entropy [J/(kg.K)] |
Explicit upper specific entropy limit of region 1 as function of pressure (meets region 4 saturation pressure curve at 623.15 K)
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | Specific entropy [J/(kg.K)] |
Explicit lower specific enthalpy limit of region 2 as function of pressure (meets region 4 saturation pressure curve at 623.15 K)
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Explicit upper specific enthalpy limit of region 2 as function of pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Explicit lower specific entropy limit of region 2 as function of pressure (meets region 4 saturation pressure curve at 623.15 K)
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | Specific entropy [J/(kg.K)] |
Explicit upper specific entropy limit of region 2 as function of pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | Specific entropy [J/(kg.K)] |
Density in region 1 as function of p and T
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
T | Temperature (K) [K] |
Name | Description |
---|---|
d | Density [kg/m3] |
Density in region 2 as function of p and T
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
T | Temperature (K) [K] |
Name | Description |
---|---|
d | Density [kg/m3] |
Density at upper temperature limit of region 1
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
d | Density [kg/m3] |
Density at upper pressure limit of region 1
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
T | Temperature (K) [K] |
Name | Description |
---|---|
d | Density [kg/m3] |
Explicit approximation of liquid specific enthalpy on the boundary between regions 4 and 3
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Explicit approximation of vapour specific enthalpy on the boundary between regions 4 and 3
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Explicit approximation of liquid specific entropy on the boundary between regions 4 and 3
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | Specific entropy [J/(kg.K)] |
Explicit approximation of vapour specific entropy on the boundary between regions 4 and 3
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | [J/(kg.K)] |
Explicit approximation of liquid density on the boundary between regions 4 and 3
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
dl | Liquid density [kg/m3] |
Explicit approximation of vapour density on the boundary between regions 4 and 2
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
dv | Vapour density [kg/m3] |
Properties on the boiling curve
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
bpro | Property record |
Properties on the dew curve
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
bpro | Property record |
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
bpro | Property record |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Liquid specific enthalpy on the boundary between regions 4 and 3 or 1
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Vapour specific enthalpy on the boundary between regions 4 and 3 or 2
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
h | Specific enthalpy [J/kg] |
Derivative function for the specific enthalpy along the phase boundary
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
bpro | Property record |
p_der | Derivative of pressure |
Name | Description |
---|---|
h_der | Time derivative of specific enthalpy along the phase boundary |
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
bpro | Property record |
Name | Description |
---|---|
rho | Density [kg/m3] |
Density of saturated water
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Saturation pressure [Pa] |
Name | Description |
---|---|
rho | Density of steam at the condensation point [kg/m3] |
Density of saturated vapour
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Saturation pressure [Pa] |
Name | Description |
---|---|
rho | Density of steam at the condensation point [kg/m3] |
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Saturation pressure [Pa] |
bpro | Property record |
p_der | Derivative of pressure |
Name | Description |
---|---|
d_der | Time derivative of density along the phase boundary |
Liquid specific entropy on the boundary between regions 4 and 3 or 1
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | Specific entropy [J/(kg.K)] |
Vapour specific entropy on the boundary between regions 4 and 3 or 2
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
s | Specific entropy [J/(kg.K)] |
Density of saturated water
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
T | Temperature [K] |
Name | Description |
---|---|
d | Density of water at the boiling point [kg/m3] |
Density of saturated vapour
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
T | Temperature [K] |
Name | Description |
---|---|
d | Density of steam at the condensation point [kg/m3] |
Return the current region (valid values: 1,2,3,4,5) in IF97 for given pressure and specific enthalpy
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
h | Specific enthalpy [J/kg] |
phase | Phase: 2 for two-phase, 1 for one phase, 0 if not known |
mode | Mode: 0 means check, otherwise assume region=mode |
Name | Description |
---|---|
region | Region (valid values: 1,2,3,4,5) in IF97 |
Return the current region (valid values: 1,2,3,4,5) in IF97 for given pressure and specific entropy
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
s | Specific entropy [J/(kg.K)] |
phase | Phase: 2 for two-phase, 1 for one phase, 0 if unknown |
mode | Mode: 0 means check, otherwise assume region=mode |
Name | Description |
---|---|
region | Region (valid values: 1,2,3,4,5) in IF97 |
Return the current region (valid values: 1,2,3,5) in IF97, given pressure and temperature
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
T | Temperature (K) [K] |
mode | Mode: 0 means check, otherwise assume region=mode |
Name | Description |
---|---|
region | Region (valid values: 1,2,3,5) in IF97, region 4 is impossible! |
Return the current region (valid values: 1,2,3,4,5) in IF97, given density and temperature
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
d | Density [kg/m3] |
T | Temperature (K) [K] |
phase | Phase: 2 for two-phase, 1 for one phase, 0 if not known |
mode | Mode: 0 means check, otherwise assume region=mode |
Name | Description |
---|---|
region | (valid values: 1,2,3,4,5) in IF97 |
Derivative function for the specific enthalpy along the phase boundary
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
bpro | Property record |
Name | Description |
---|---|
dh_dp | Derivative of specific enthalpy along the phase boundary |
Derivative of liquid specific enthalpy on the boundary between regions 4 and 3 or 1 w.r.t. pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
dh_dp | Specific enthalpy derivative w.r.t. pressure [J.m.s2/kg2] |
Derivative of vapour specific enthalpy on the boundary between regions 4 and 3 or 1 w.r.t. pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Pressure [Pa] |
Name | Description |
---|---|
dh_dp | Specific enthalpy derivative w.r.t. pressure [J.m.s2/kg2] |
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Saturation pressure [Pa] |
bpro | Property record |
Name | Description |
---|---|
dd_dp | Derivative of density along the phase boundary [kg/(m3.Pa)] |
Derivative of density of saturated water w.r.t. pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Saturation pressure [Pa] |
Name | Description |
---|---|
dd_dp | Derivative of density of water at the boiling point [s2/m2] |
Derivative of density of saturated steam w.r.t. pressure
Extends from Modelica.Icons.Function (Icon for functions).
Name | Description |
---|---|
p | Saturation pressure [Pa] |
Name | Description |
---|---|
dd_dp | Derivative of density of water at the boiling point [s2/m2] |