lib.PR78 module¶
- class lib.EoS.Cubic.PR78.PR78(T, P, mezcla, **kwargs)[source]¶
Bases:
PRPeng-Robinson cubic equation of state
\[\begin{split}\begin{array}[t]{l} P = \frac{RT}{V-b}-\frac{a}{V\left(V+b\right)+b\left(V-b\right)}\\ a = 0.45747\frac{R^2T_c^2}{P_c}\alpha\\ b = 0.0778\frac{RT_c}{P_c}\\ \alpha^{0.5} = 1 + m\left(1-Tr^{0.5}\right)\\ m = 0.37464 + 1.54226\omega-0.26992\omega^2 if \omega < 0.491\\ m = 0.379642 + 1.48503\omega - 0.164423*\omega^2 + 0.016666*\omega^3\\ \end{array}\end{split}\]Examples
Helmholtz energy formulation example for supplementary documentatión from [4]_, the critical parameter are override for the valued used in paper to get the values of test with high precision
>>> from lib.mezcla import Mezcla >>> from lib import unidades >>> from lib.compuestos import Componente >>> ch4 = Componente(2) >>> ch4.Tc, ch4.Pc, ch4.f_acent = 190.564, 4599200, 0.011 >>> o2 = Componente(47) >>> o2.Tc, o2.Pc, o2.f_acent = 154.581, 5042800, 0.022 >>> ar = Componente(98) >>> ar.Tc, ar.Pc, ar.f_acent = 150.687, 4863000, -0.002 >>> mix = Mezcla(5, customCmp=[ch4, o2, ar], caudalMolar=1, ... fraccionMolar=[0.5, 0.3, 0.2]) >>> eq = PR78(800, 36451227.52066596, mix, R=8.3144598) >>> fir = eq._phir(800, 5000, eq.yi) >>> delta = 5000 >>> tau = 1/800 >>> print("fir: %0.15f" % (fir["fir"])) fir: 0.084339749584296 >>> print("fird: %0.15f" % (fir["fird"]*delta)) fird: 0.096019116018396 >>> print("firt: %0.14f" % (fir["firt"]*tau)) firt: -0.10134978074971 >>> print("firdd: %0.15f" % (fir["firdd"]*delta**2)) firdd: 0.023611667278971 >>> print("firdt: %0.15f" % (fir["firdt"]*delta*tau)) firdt: -0.092099683110520 >>> print("firtt: %0.15f" % (fir["firtt"]*tau**2)) firtt: -0.078186052271240 >>> print("firddd: %0.16f" % (fir["firddd"]*delta**3)) firddd: 0.0017433108161805 >>> print("firddt: %0.15f" % (fir["firddt"]*delta**2*tau)) firddt: 0.015574974734224 >>> print("firdtt: %0.15f" % (fir["firdtt"]*delta*tau**2)) firdtt: -0.071050085995025 >>> print("firttt: %0.14f" % (fir["firttt"]*tau**3)) firttt: 0.11727907840686
