.Modelica.Media.Water.IF97_Utilities.BaseIF97.Basic

Information

Package description

Package BaseIF97/Basic computes the fundamental functions for the 5 regions of the steam tables as described in the standards document IF97.pdf. The code of these functions has been generated using Mathematica and the add-on packages "Format" and "Optimize" to generate highly efficient, expression-optimized C-code from a symbolic representation of the thermodynamic functions. The C-code has than been transformed into Modelica code. An important feature of this optimization was to simultaneously optimize the functions and the directional derivatives because they share many common subexpressions.

Package contents

• Function g1 computes the dimensionless Gibbs function for region 1 and all derivatives up to order 2 w.r.t. pi and tau. Inputs: p and T.
• Function g2 computes the dimensionless Gibbs function for region 2 and all derivatives up to order 2 w.r.t. pi and tau. Inputs: p and T.
• Function g2metastable computes the dimensionless Gibbs function for metastable vapour (adjacent to region 2 but 2-phase at equilibrium) and all derivatives up to order 2 w.r.t. pi and tau. Inputs: p and T.
• Function f3 computes the dimensionless Helmholtz function for region 3 and all derivatives up to order 2 w.r.t. delta and tau. Inputs: d and T.
• Function g5computes the dimensionless Gibbs function for region 5 and all derivatives up to order 2 w.r.t. pi and tau. Inputs: p and T.
• Function tph1 computes the inverse function T(p,h) in region 1.
• Function tph2 computes the inverse function T(p,h) in region 2.
• Function tps2a computes the inverse function T(p,s) in region 2a.
• Function tps2b computes the inverse function T(p,s) in region 2b.
• Function tps2c computes the inverse function T(p,s) in region 2c.
• Function tps2 computes the inverse function T(p,s) in region 2.
• Function tsat computes the saturation temperature as a function of pressure.
• Function dtsatofp computes the derivative of the saturation temperature w.r.t. pressure as a function of pressure.
• Function tsat_der computes the Modelica derivative function of tsat.
• Function psat computes the saturation pressure as a function of temperature.
• Function dptofT computes the derivative of the saturation pressure w.r.t. temperature as a function of temperature.
• Function psat_der computes the Modelica derivative function of psat.

Version Info and Revision history

• First implemented: July, 2000 by Hubertus Tummescheit

• Initial version: July 2000
• Documentation added: December 2002

Equation from:

Contents

Name	Description
g1	Gibbs function for region 1: g(p,T)
g2	Gibbs function for region 2: g(p,T)
g2metastable	Gibbs function for metastable part of region 2: g(p,T)
f3	Helmholtz function for region 3: f(d,T)
g5	Base function for region 5: g(p,T)
gibbs	Gibbs function for region 1, 2 or 5: g(p,T,region)
g1pitau	Derivative of g w.r.t. pi and tau
g2pitau	Derivative of g w.r.t. pi and tau
g5pitau	Derivative of g w.r.t. pi and tau
f3deltatau	1st derivatives of f w.r.t. delta and tau
tph1	Inverse function for region 1: T(p,h)
tps1	Inverse function for region 1: T(p,s)
tph2	Reverse function for region 2: T(p,h)
tps2a	Reverse function for region 2a: T(p,s)
tps2b	Reverse function for region 2b: T(p,s)
tps2c	Reverse function for region 2c: T(p,s)
tps2	Reverse function for region 2: T(p,s)
tsat	Region 4 saturation temperature as a function of pressure
dtsatofp	Derivative of saturation temperature w.r.t. pressure
tsat_der	Derivative function for tsat
psat	Region 4 saturation pressure as a function of temperature
dptofT	Derivative of pressure w.r.t. temperature along the saturation pressure curve
psat_der	Derivative function for psat
p1_hs	Pressure as a function of enthalpy and entropy in region 1
h2ab_s	Boundary between regions 2a and 2b
p2a_hs	Pressure as a function of enthalpy and entropy in subregion 2a
p2b_hs	Pressure as a function of enthalpy and entropy in subregion 2a
p2c_hs	Pressure as a function of enthalpy and entropy in subregion 2c
h3ab_p	Region 3 a b boundary for pressure/enthalpy
T3a_ph	Region 3 a: inverse function T(p,h)
T3b_ph	Region 3 b: inverse function T(p,h)
v3a_ph	Region 3 a: inverse function v(p,h)
v3b_ph	Region 3 b: inverse function v(p,h)
T3a_ps	Region 3 a: inverse function T(p,s)
T3b_ps	Region 3 b: inverse function T(p,s)
v3a_ps	Region 3 a: inverse function v(p,s)
v3b_ps	Region 3 b: inverse function v(p,s)