dtofphOnePhase

Density and temperature w.r.t. pressure and specific enthalpy in one-phase region

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

This function calculates the density and temperature of R134a from absolute pressure and specific enthalpy in one-phase region. The function calls the fundamental Helmholtz equation of Tillner-Roth (1994) which is requiring density and temperature for input. Thus, a newton iteration is performed to determine density and temperature. The newton iteration stops if the inputs for pressure difference delp and specific enthalpy difference delh are larger than the actual differences derived from the newton iteration.

Restrictions

The function shall only be used for one-phase inputs since the fundamental equation is not valid for two-phase states.

Syntax

(d, T, error) = dtofphOnePhase(p, h, delp, delh)

Inputs (4)

p

Type: AbsolutePressure (Pa)

Description: Pressure

h

Type: SpecificEnthalpy (J/kg)

Description: Enthalpy

delp

Type: AbsolutePressure (Pa)

Description: Absolute error in p in iteration

delh

Type: SpecificEnthalpy (J/kg)

Description: Absolute error in h in iteration

Outputs (3)

d

Type: Density (kg/m³)

Description: Density

T

Type: Temperature (K)

Description: Temperature

error

Type: Integer

Description: 1 if did not converged