How to use the pcsaft.flashTQ function in pcsaft
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zmeri / PC-SAFT / tests / test_cython.py View on Github 
assert abs((calc-ref)/ref*100) < 3
# Binary mixture: methane-benzene
#0 = methane, 1 = benzene
x = np.asarray([0.0252,0.9748])
m = np.asarray([1.0000, 2.4653])
s = np.asarray([3.7039, 3.6478])
e = np.asarray([150.03, 287.35])
k_ij = np.asarray([[0, 0.037],
[0.037, 0]])
pyargs = {'m':m, 's':s, 'e':e, 'k_ij':k_ij}
t = 421.05
ref = 1986983.25 # source: H.-M. Lin, H. M. Sebastian, J. J. Simnick, and K.-C. Chao, “Gas-liquid equilibrium in binary mixtures of methane with N-decane, benzene, and toluene,” J. Chem. Eng. Data, vol. 24, no. 2, pp. 146–149, Apr. 1979.
xv_ref = np.asarray([0.6516,0.3484])
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('\n########## Test with methane-benzene mixture ##########')
print('----- Bubble point pressure at %s K -----' % t)
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
print(' Vapor composition (reference):', xv_ref)
print(' Vapor composition (PC-SAFT):', xv)
print(' Vapor composition relative deviation:', (xv-xv_ref)/xv_ref*100)
assert abs((calc-ref)/ref*100) < 10
assert np.all(abs((xv-xv_ref)/xv_ref*100) < 10)
# # Binary mixture: hydrogen-hexadecane
# # This does not pass yet. The flash functions still need to be improved.
# #0 = hydrogen, 1 = hexadecane
# x = np.asarray([0.0407, 0.9593])#0 = methanol, 1 = cyclohexane
x = np.asarray([0.3,0.7])
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 = {'m':m, 's':s, 'e':e, 'e_assoc':eAB, 'vol_a':volAB, 'k_ij':k_ij}
# bubble point
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
t = 327.48
xv_ref = np.asarray([0.59400,0.40600])
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('\n########## Test with methanol-cyclohexane mixture ##########')
print('----- Bubble point pressure at 327.48 K -----')
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
print(' Vapor composition (reference):', xv_ref)
print(' Vapor composition (PC-SAFT):', xv)
print(' Vapor composition relative deviation:', (xv-xv_ref)/xv_ref*100)
assert abs((calc-ref)/ref*100) < 10
assert np.all(abs((xv-xv_ref)/xv_ref*100) < 10)
# dew point
x = np.asarray([0.59400,0.40600])
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
t = 327.48print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 5
ref = 8.3324e5 # source: reference EOS in CoolProp
t = 293
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('----- Vapor pressure at {} K -----'.format(t))
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3
ref = 42.477e5 # source: reference EOS in CoolProp
t = 369.82
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('----- Vapor pressure at {} K -----'.format(t))
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3
# Binary mixture: methane-benzene
#0 = methane, 1 = benzene
x = np.asarray([0.0252,0.9748])
m = np.asarray([1.0000, 2.4653])
s = np.asarray([3.7039, 3.6478])
e = np.asarray([150.03, 287.35])
k_ij = np.asarray([[0, 0.037],
[0.037, 0]])
pyargs = {'m':m, 's':s, 'e':e, 'k_ij':k_ij}print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3
# Acetic acid
m = np.asarray([1.3403])
s = np.asarray([3.8582])
e = np.asarray([211.59])
volAB = np.asarray([0.075550])
eAB = np.asarray([3044.4])
pyargs = {'m':m, 's':s, 'e':e, 'e_assoc':eAB, 'vol_a':volAB}
ref = 193261.515187248 # source: DIPPR correlation
t = 413.5385
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('\n########## Test with acetic acid ##########')
print('----- Vapor pressure at 413.5 K -----')
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3
# Dimethyl ether
m = np.asarray([2.2634])
s = np.asarray([3.2723])
e = np.asarray([210.29])
dpm = np.asarray([1.3])
dip_num = np.asarray([1.0])
pyargs = {'m':m, 's':s, 'e':e, 'dipm':dpm, 'dip_num':dip_num}def test_flashTQ(print_result=False):
"""Test the flashTQ function to see if it is working correctly."""
# Toluene
x = np.asarray([1.])
m = np.asarray([2.8149])
s = np.asarray([3.7169])
e = np.asarray([285.69])
pyargs = {'m':m, 's':s, 'e':e}
ref = 3255792.76201971 # source: reference EOS in CoolProp
t = 572.6667
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('########## Test with toluene ##########')
print('----- Vapor pressure at 572.7 K -----')
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3
# Water
m = np.asarray([1.2047])
e = np.asarray([353.95])
volAB = np.asarray([0.0451])
eAB = np.asarray([2425.67])
ref = 67171.754576141 # source: IAWPS95 EOS
t = 362print('----- Vapor pressure at 300 K -----')
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3
# Propane
x = np.asarray([1.])
m = np.asarray([2.0020])
s = np.asarray([3.6184])
e = np.asarray([208.11])
pyargs = {'m':m, 's':s, 'e':e}
ref = 1.7551e-4 # source: reference EOS in CoolProp
t = 85.525
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('########## Test with propane ##########')
print('----- Vapor pressure at {} K -----'.format(t))
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 5
ref = 8.3324e5 # source: reference EOS in CoolProp
t = 293
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('----- Vapor pressure at {} K -----'.format(t))
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')print(' Reference pressure:', ref, 'Pa')
print(' PC-SAFT pressure:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
print(' Vapor composition (reference):', xv_ref)
print(' Vapor composition (PC-SAFT):', xv)
print(' Vapor composition relative deviation:', (xv-xv_ref)/xv_ref*100)
assert abs((calc-ref)/ref*100) < 10
assert np.all(abs((xv-xv_ref)/xv_ref*100) < 15)
xl_ref = np.asarray([0.2691800943, 0.7308199057])
t = 372.774
s[0] = 3.8395 + 1.2828*np.exp(-0.0074944*t) - 1.3939*np.exp(-0.00056029*t)
pyargs = {'m':m, 's':s, 'e':e, 'e_assoc':eAB, 'vol_a':volAB, 'k_ij':k_ij}
ref = 74463. # source: Freeman, J. R.; Wilson, G. M. AIChE Symp. Ser., 1985, 81, 14-25 High temperature vapor-liquid equilibrium measurements on acetic acid/water mixtures
xv_ref = np.asarray([0.3878269411, 0.6121730589])
calc, xl, xv = flashTQ(t, 0, xl_ref, pyargs)
if print_result:
print('----- Bubble point pressure at %s K -----' % t)
print(' Liquid composition:', xl_ref)
print(' Reference pressure:', ref, 'Pa')
print(' PC-SAFT pressure:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
print(' Vapor composition (reference):', xv_ref)
print(' Vapor composition (PC-SAFT):', xv)
print(' Vapor composition relative deviation:', (xv-xv_ref)/xv_ref*100)
assert abs((calc-ref)/ref*100) < 10
assert np.all(abs((xv-xv_ref)/xv_ref*100) < 15)
# NaCl in water
# 0 = Na+, 1 = Cl-, 2 = H2O
x = np.asarray([0.0907304774758426, 0.0907304774758426, 0.818539045048315])
m = np.asarray([1, 1, 1.2047])print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3
# Water
m = np.asarray([1.2047])
e = np.asarray([353.95])
volAB = np.asarray([0.0451])
eAB = np.asarray([2425.67])
ref = 67171.754576141 # source: IAWPS95 EOS
t = 362
s = np.asarray([2.7927 + 10.11*np.exp(-0.01775*t) - 1.417*np.exp(-0.01146*t)])
pyargs = {'m':m, 's':s, 'e':e, 'e_assoc':eAB, 'vol_a':volAB}
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('\n########## Test with water ##########')
print('----- Vapor pressure at 362 K -----')
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3
# Acetic acid
m = np.asarray([1.3403])
s = np.asarray([3.8582])
e = np.asarray([211.59])
volAB = np.asarray([0.075550])
eAB = np.asarray([3044.4])
pyargs = {'m':m, 's':s, 'e':e, 'e_assoc':eAB, 'vol_a':volAB}#0 = water, 1 = acetic acid
m = np.asarray([1.2047, 1.3403])
s = np.asarray([0, 3.8582])
e = np.asarray([353.95, 211.59])
volAB = np.asarray([0.0451, 0.075550])
eAB = np.asarray([2425.67, 3044.4])
k_ij = np.asarray([[0, -0.127],
[-0.127, 0]])
xl_ref = np.asarray([0.9898662364, 0.0101337636])
t = 403.574
s[0] = 3.8395 + 1.2828*np.exp(-0.0074944*t) - 1.3939*np.exp(-0.00056029*t)
pyargs = {'m':m, 's':s, 'e':e, 'e_assoc':eAB, 'vol_a':volAB, 'k_ij':k_ij}
ref = 273722. # source: Othmer, D. F.; Silvis, S. J.; Spiel, A. Ind. Eng. Chem., 1952, 44, 1864-72 Composition of vapors from boiling binary solutions pressure equilibrium still for studying water - acetic acid system
xv_ref = np.asarray([0.9923666645, 0.0076333355])
calc, xl, xv = flashTQ(t, 0, xl_ref, pyargs)
if print_result:
print('\n########## Test with water-acetic acid mixture ##########')
print('----- Bubble point pressure at %s K -----' % t)
print(' Liquid composition:', xl_ref)
print(' Reference pressure:', ref, 'Pa')
print(' PC-SAFT pressure:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
print(' Vapor composition (reference):', xv_ref)
print(' Vapor composition (PC-SAFT):', xv)
print(' Vapor composition relative deviation:', (xv-xv_ref)/xv_ref*100)
assert abs((calc-ref)/ref*100) < 10
assert np.all(abs((xv-xv_ref)/xv_ref*100) < 15)
xl_ref = np.asarray([0.2691800943, 0.7308199057])
t = 372.774
s[0] = 3.8395 + 1.2828*np.exp(-0.0074944*t) - 1.3939*np.exp(-0.00056029*t)pyargs = {'m':m, 's':s, 'e':e}
ref = 1.7551e-4 # source: reference EOS in CoolProp
t = 85.525
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('########## Test with propane ##########')
print('----- Vapor pressure at {} K -----'.format(t))
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 5
ref = 8.3324e5 # source: reference EOS in CoolProp
t = 293
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('----- Vapor pressure at {} K -----'.format(t))
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3
ref = 42.477e5 # source: reference EOS in CoolProp
t = 369.82
calc, xl, xv = flashTQ(t, 0, x, pyargs)
if print_result:
print('----- Vapor pressure at {} K -----'.format(t))
print(' Reference:', ref, 'Pa')
print(' PC-SAFT:', calc, 'Pa')
print(' Relative deviation:', (calc-ref)/ref*100, '%')
assert abs((calc-ref)/ref*100) < 3pcsaft
The PC-SAFT equation of state, including dipole, association and ion terms.
