def test_PTz():
"""Test the function for PTz data to see if it is working correctly."""
# Binary mixture: methanol-cyclohexane
print('\n########## Test with methanol-cyclohexane mixture ##########')
#0 = methanol, 1 = cyclohexane
m = np.asarray([1.5255, 2.5303])
s = np.asarray([3.2300, 3.8499])
e = np.asarray([188.90, 278.11])
volAB = np.asarray([0.035176, 0.])
eAB = np.asarray([2899.5, 0.])
k_ij = np.asarray([[0, 0.051],
[0.051, 0]])
mol = 1.
t = 327.48
p_ref = 101330 # source: Marinichev A.N.; Susarev M.P.: Investigation of Liquid-Vapor Equilibrium in the System Methanol-Cyclohexane at 35, 45 and 55°C and 760 mm Hg. J.Appl.Chem.USSR 38 (1965) 1582-1584
xl_ref = np.asarray([0.3,0.7])
xv_ref = np.asarray([0.59400,0.40600])
beta_ref = 0.6
xtot = (beta_ref*mol*xv_ref + (1-beta_ref)*mol*xl_ref)/mol
rho_l = pcsaft_den(xl_ref, m, s, e, t, p_ref, phase='liq', k_ij=k_ij, e_assoc=eAB, vol_a=volAB)
rho_v = pcsaft_den(xv_ref, m, s, e, t, p_ref, phase='vap', k_ij=k_ij, e_assoc=eAB, vol_a=volAB)
vol = beta_ref*mol/rho_v + (1-beta_ref)*mol/rho_l
result = pcsaft_PTz(p_ref, xl_ref, beta_ref, mol, vol, xtot, m, s, e, t, k_ij=k_ij, e_assoc=eAB, vol_a=volAB)
p_calc = result[0]
xl_calc = result[1]
xv_calc = result[2]
beta_calc = result[3]
print('----- Pressure at 327.48 K -----')
print(' Reference:', p_ref, 'Pa')
print(' PC-SAFT:', p_calc, 'Pa')
print(' Relative deviation:', (p_calc-p_ref)/p_ref*100, '%')
print('----- Liquid phase composition -----')
print(' Reference:', xl_ref)
print(' PC-SAFT:', xl_calc)
print(' Relative deviation:', (xl_calc-xl_ref)/xl_ref*100, '%')
print('----- Vapor phase composition -----')
print(' Reference:', xv_ref)
print(' PC-SAFT:', xv_calc)
print(' Relative deviation:', (xv_calc-xv_ref)/xv_ref*100, '%')
print('----- Beta -----')
print(' Reference:', beta_ref)
print(' PC-SAFT:', beta_calc)
print(' Relative deviation:', (beta_calc-beta_ref)/beta_ref*100, '%')
return None
def test_PTz():
"""Test the function for PTz data to see if it is working correctly."""
# Binary mixture: methanol-cyclohexane
print('\n########## Test with methanol-cyclohexane mixture ##########')
#0 = methanol, 1 = cyclohexane
m = np.asarray([1.5255, 2.5303])
s = np.asarray([3.2300, 3.8499])
e = np.asarray([188.90, 278.11])
volAB = np.asarray([0.035176, 0.])
eAB = np.asarray([2899.5, 0.])
k_ij = np.asarray([[0, 0.051], [0.051, 0]])
pyargs = {'e_assoc': eAB, 'vol_a': volAB, 'k_ij': k_ij}
mol = 1.
t = 327.48
p_ref = 101330 # source: Marinichev A.N.; Susarev M.P.: Investigation of Liquid-Vapor Equilibrium in the System Methanol-Cyclohexane at 35, 45 and 55°C and 760 mm Hg. J.Appl.Chem.USSR 38 (1965) 1582-1584
xl_ref = np.asarray([0.3, 0.7])
xv_ref = np.asarray([0.59400, 0.40600])
beta_ref = 0.6
xtot = (beta_ref * mol * xv_ref + (1 - beta_ref) * mol * xl_ref) / mol
rho_l = pcsaft_den(xl_ref, m, s, e, t, p_ref, pyargs, phase='liq')
rho_v = pcsaft_den(xv_ref, m, s, e, t, p_ref, pyargs, phase='vap')
vol = beta_ref * mol / rho_v + (1 - beta_ref) * mol / rho_l
result = pcsaft_PTz(p_ref, xl_ref, beta_ref, mol, vol, xtot, m, s, e, t,
pyargs)
p_calc = result[0]
xl_calc = result[1]
xv_calc = result[2]
beta_calc = result[3]
print('----- Pressure at 327.48 K -----')
print(' Reference:', p_ref, 'Pa')
print(' PC-SAFT:', p_calc, 'Pa')
print(' Relative deviation:', (p_calc - p_ref) / p_ref * 100, '%')
print('----- Liquid phase composition -----')
print(' Reference:', xl_ref)
print(' PC-SAFT:', xl_calc)
print(' Relative deviation:', (xl_calc - xl_ref) / xl_ref * 100, '%')
print('----- Vapor phase composition -----')
print(' Reference:', xv_ref)
print(' PC-SAFT:', xv_calc)
print(' Relative deviation:', (xv_calc - xv_ref) / xv_ref * 100, '%')
print('----- Beta -----')
print(' Reference:', beta_ref)
print(' PC-SAFT:', beta_calc)
print(' Relative deviation:', (beta_calc - beta_ref) / beta_ref * 100,
'%')
#
# # NaCl in water
print('\n########## Test with aqueous NaCl ##########')
# 0 = Na+, 1 = Cl-, 2 = H2O
m = np.asarray([1, 1, 1.2047])
s = np.asarray([2.8232, 2.7599589, 0.])
e = np.asarray([230.00, 170.00, 353.9449])
volAB = np.asarray([0, 0, 0.0451])
eAB = np.asarray([0, 0, 2425.67])
k_ij = np.asarray([[0, 0.317, 0], [0.317, 0, -0.25], [0, -0.25, 0]])
z = np.asarray([1., -1., 0.])
p_ref = 2393.8 # average of repeat data points from source: A. Apelblat and E. Korin, “The vapour pressures of saturated aqueous solutions of sodium chloride, sodium bromide, sodium nitrate, sodium nitrite, potassium iodate, and rubidium chloride at temperatures from 227 K to 323 K,” J. Chem. Thermodyn., vol. 30, no. 1, pp. 59–71, Jan. 1998. (Solubility calculated using equation from Yaws, Carl L.. (2008). Yaws' Handbook of Properties for Environmental and Green Engineering.)
t = 298.15 # K
s[2] = 2.7927 + 10.11 * np.exp(-0.01775 * t) - 1.417 * np.exp(
-0.01146 * t) # temperature dependent segment diameter for water
k_ij[0, 2] = -0.007981 * t + 2.37999
k_ij[2, 0] = -0.007981 * t + 2.37999
dielc = dielc_water(t)
pyargs = {
'e_assoc': eAB,
'vol_a': volAB,
'k_ij': k_ij,
'z': z,
'dielc': dielc
}
mol = 1.
xl_ref = np.asarray(
[0.0907304774758426, 0.0907304774758426, 0.818539045048315])
xv_ref = np.asarray([0., 0, 1])
beta_ref = 0.001
xtot = (beta_ref * mol * xv_ref + (1 - beta_ref) * mol * xl_ref) / mol
rho_l = pcsaft_den(xl_ref, m, s, e, t, p_ref, pyargs, phase='liq')
rho_v = pcsaft_den(xv_ref, m, s, e, t, p_ref, pyargs, phase='vap')
vol = beta_ref * mol / rho_v + (1 - beta_ref) * mol / rho_l
result = pcsaft_PTz(p_ref, xl_ref, beta_ref, mol, vol, xtot, m, s, e, t,
pyargs)
p_calc = result[0]
xl_calc = result[1]
xv_calc = result[2]
beta_calc = result[3]
print('----- Pressure at 298.15 K -----')
print(' Reference:', p_ref, 'Pa')
print(' PC-SAFT:', p_calc, 'Pa')
print(' Relative deviation:', (p_calc - p_ref) / p_ref * 100, '%')
print('----- Liquid phase composition -----')
print(' Reference:', xl_ref)
print(' PC-SAFT:', xl_calc)
print(' Relative deviation:', (xl_calc - xl_ref) / xl_ref * 100, '%')
print('----- Vapor phase composition -----')
print(' Reference:', xv_ref)
print(' PC-SAFT:', xv_calc)
print(' Relative deviation:', (xv_calc - xv_ref) / xv_ref * 100, '%')
print('----- Beta -----')
print(' Reference:', beta_ref)
print(' PC-SAFT:', beta_calc)
print(' Relative deviation:', (beta_calc - beta_ref) / beta_ref * 100,
'%')
return None