Oil quadratic enthalpy

The oil enthalpy can be modelled using the present quadratic model which accounts for temperature dependence only. Two reference temperatures and two coefficients need to be entered.

See example below.

EOS OIL
  DENSITY CONSTANT 734.29d0 !kg/m3
    VISCOSITY CONSTANT 0.987d-3
    ENTHALPY QUADRATIC_TEMP
    TEMP_REF_VALUES 15.5555556 15.5555556 ![°C]
    TEMP_COEFFICIENTS 1.653D3 4.001d0 ![J/kg °C] [J/(kg °C °C)]
  END
END

The mathematical expression of this model is given below

\[h(T )=c_{t,1} (T −T_1 )+ \frac{1}{2} c_{t,2} (T −T_2 )^2\]

where:

\[\begin{split}\begin{split} &h(T ) &= \mbox{oil enthalpy [J/kg]}\\ &T_1 &= \mbox{linear reference temperature [C]}\\ &c_{t,1} &= \mbox{linear dependency coefficient [J/(kg C)]}\\ &T_2 &= \mbox{quadratic reference temperature [C]}\\ &c_{t,2} &= \mbox{quadratic dependency coefficient [J/(kg C C)]} \end{split}\end{split}\]

Units cannot be specified, therefore values must be entered in the units prescribed above.