lib.EoS.BWRS module¶
- class lib.EoS.BWRS.BWRS(T, P, mezcla, **kwargs)[source]¶
Bases:
EoSBenedict-Webb-Rubin equation of state modified by Starling [1]
\[\begin{split}\begin{align*} p = \rho RT + \left(B_0RT-A_0-\frac{C_0}{T^2}+\frac{D_0}{T^3}- \frac{C_0}{T^2}\right)\rho^2 + \left(bRT-a-\frac{d}{T}\right)\rho^3 \\ {} + \alpha a\left(a+\frac{d}{T}\right)\rho^6 + \frac{c\rho^3}{T^2} \left(1+\gamma \rho^2\right) \exp\left(-\gamma\rho^2\right) \end{align*}\end{split}\]This equation use 11 compound specified parameters, available for 15 common subsgtances, but there are generalized correlation of these parameters as function of critic tempereture, critic density and acentric factor, given in [2].
\[\begin{split}\begin{array}[t]{l} \rho_c B_0 = A_1 + B_1\omega\\ \rho_c \frac{A_0}{RT_c} = A_2 + B_2\omega\\ \rho_c \frac{C_0}{RT_c^3} = A_3 + B_3\omega\\ \rho_c^2 \gamma = A_4 + B_4\omega\\ \rho_c^2 b = A_5 + B_5\omega\\ \rho_c^2 \frac{a}{RT_c} = A_6 + B_6\omega\\ \rho_c^3 \alpha = A_7 + B_7\omega\\ \rho_c^2 \frac{c}{RT_c^3} = A_8 + B_8\omega\\ \rho_c \frac{D_0}{RT_c^4} = A_9 + B_9\omega\\ \rho_c^2 \frac{d}{RT_c^2} = A_{10} + B_{10}\omega\\ \rho_c \frac{E_0}{RT_c^3} = A_{11} + B_{11}\omega \exp\left(-3.8\omega\right)\\ \end{array}\end{split}\]The mixing rules to get the mixture parameters are:
\[\begin{split}\begin{array}[t]{l} A_0 = \sum_i \sum_j x_i x_j A_{0i}^{1/2} A_{0j}^{1/2} \left(1-k_ij\right)\\ B_0 = \sum_i x_i B_{0i}\\ C_0 = \sum_i \sum_j x_i x_j C_{0i}^{1/2} C_{0j}^{1/2} \left(1-k_ij\right)^3\\ D_0 = \sum_i \sum_j x_i x_j D_{0i}^{1/2} D_{0j}^{1/2} \left(1-k_ij\right)^4\\ E_0 = \sum_i \sum_j x_i x_j E_{0i}^{1/2} E_{0j}^{1/2} \left(1-k_ij\right)^5\\ \alpha = \left(\sum_i x_i \alpha_i^{1/3}\right)^3\\ \gamma = \left(\sum_i x_i \gamma_i^{1/2}\right)^2\\ a = \left(\sum_i x_i a_i^{1/3}\right)^3\\ b = \left(\sum_i x_i b_i^{1/3}\right)^3\\ c = \left(\sum_i x_i c_i^{1/3}\right)^3\\ d = \left(\sum_i x_i d_i^{1/3}\right)^3\\ \end{array}\end{split}\]This model is very accurate for VLE for light normal hydrocarbons.
The model include too the low reduced temperatures extensión from [2] with four aditional compound specific parameters
\[\begin{split}\begin{align*} p = \rho RT + \left(B_0RT-A_0-\frac{C_0}{T^2}+\frac{D_0}{T^3}- \frac{C_0}{T^2}\right)\rho^2 + \left(bRT-a-\frac{d}{T}-\frac{e}{T^4}-\frac{f}{T^{23}}\right)\rho^3 \\ {} + \alpha \left(a+\frac{d}{T}+\frac{e}{T^4}+\frac{f}{T^{23}}\right) \rho^6 + \left(\frac{c}{T^2}+\frac{g}{T^8}+\frac{h}{T^{17}}\right) \rho^3 \left(1+\gamma \rho^2\right) \exp\left(-\gamma\rho^2\right) \end{align*}\end{split}\]with generalized correlation of this new parameters and with this mixing rules
\[\begin{split}\begin{array}[t]{l} e = \left(\sum_i x_i e_i^{1/3}\right)^3\\ f = \left(\sum_i x_i f_i^{1/3}\right)^3\\ g = \sum_i x_i g_i\\ h = \sum_i x_i h_i\\ \end{array}\end{split}\]- __init__(T, P, mezcla, **kwargs)[source]¶
For use the extended version use the “extended” parameters with value True
- _fug(xi, yi, T, P)[source]¶
Fugacities of component in mixture calculation
- Parameters:
- xilist
Molar fraction of component in liquid phase, [-]
- yilist
Molar fraction of component in vapor phase, [-]
- Returns:
- titallist
List with liquid phase component fugacities
- titavlist
List with vapour phase component fugacities
