This function calculates the time derivative of vapor enthalpy of R134a with regard to the time derivative of p. The non-derivative function is dewEnthalpy.
It is only valid in the two-phase region (i.e., ptriple ≤ p ≤ pcrit ).
function dDewEnthalpy_dPressure_der_sat extends Modelica.Icons.Function; input SaturationProperties sat "saturation properties | pressure is used for interpolation"; input SaturationProperties der_sat "derivative of saturation properties"; output Real der_dhvdp "derivative of vapor specific enthalpy in two-phase region w.r.t pressure"; end dDewEnthalpy_dPressure_der_sat;