def test_CharLine_evaluation():
"""Test the characteristc line evaluation."""
# create a characteristc line with values of y=(x-2)^2
line = CharLine(x=[0, 1, 2, 3, 4], y=[4, 1, 0, 1, 4])
# test evaluation at given x value (x=3, y=1)
x = 3
y = line.evaluate(x)
msg = ('The evaluation of x=' + str(x) + ' must be 1.0, but is ' + str(y) +
'.')
assert y == 1.0, msg
# test evaluation at x=0.5 to force interpolation, result: y=2.5
x = 0.5
y = line.evaluate(x)
msg = ('The evaluation of x=' + str(x) + ' must be 2.5, but is ' + str(y) +
'.')
assert y == 2.5, msg
# test evaluation at x=-1 to check lower limits, result: y=4
x = -1
y = line.evaluate(x)
msg = ('The evaluation of x=' + str(x) + ' must be 4, but is ' + str(y) +
'.')
assert y == 4.0, msg
# test evaluation at x=5 to check upper limits, result: y=4
x = 5
y = line.evaluate(x)
msg = ('The evaluation of x=' + str(x) + ' must be 4, but is ' + str(y) +
'.')
assert y == 4.0, msg
def test_CharLine_extrapolation():
"""Test the characteristc line with extrapolation."""
# create a characteristc line with values of y=(x-2)^2
line = CharLine(x=[0, 1, 2, 3, 4], y=[4, 1, 0, 1, 4], extrapolate=True)
# test evaluation at x=-1 to check lower limits, result: y=7
x = -1
y = line.evaluate(x)
msg = ('The evaluation of x=' + str(x) + ' must be 7, but is ' + str(y) +
'.')
assert y == 7.0, msg
# test evaluation at x=5 to check upper limits, result: y=7
x = 5
y = line.evaluate(x)
msg = ('The evaluation of x=' + str(x) + ' must be 7, but is ' + str(y) +
'.')
assert y == 7.0, msg
def test_Valve(self):
"""Test component properties of valves."""
instance = Valve('valve')
self.setup_piping_network(instance)
# parameter specification
self.c1.set_attr(fluid={'CH4': 1}, m=10, p=10, T=120)
self.c2.set_attr(p=1)
# test variable pressure ration
instance.set_attr(pr='var')
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
pr = round(self.c2.p.val_SI / self.c1.p.val_SI, 2)
msg = ('Value of pressure ratio must be ' + str(pr) + ', is ' +
str(round(instance.pr.val, 2)) + '.')
assert pr == round(instance.pr.val, 2), msg
# test variable zeta value
zeta = round(instance.zeta.val, 0)
instance.set_attr(zeta='var', pr=None)
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
msg = ('Value of dimension independent zeta value must be ' +
str(zeta) + ', is ' + str(round(instance.zeta.val, 0)) + '.')
assert zeta == round(instance.zeta.val, 0), msg
# dp char
x = np.array([8, 9, 10, 11, 12])
y = np.array([5, 8, 9, 9.5, 9.6]) * 1e5
dp_char = CharLine(x, y)
instance.set_attr(zeta=None,
dp_char={
'char_func': dp_char,
'is_set': True
})
m = 11
self.c1.set_attr(m=m)
self.c2.set_attr(p=np.nan)
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
self.nw.print_results()
dp = round(-dp_char.evaluate(m), 0)
dp_act = round(self.c2.p.val_SI - self.c1.p.val_SI)
msg = ('The pressure drop at the valve should be ' + str(dp) + ' but '
'is ' + str(dp_act) + '.')
assert dp == dp_act, msg
class TestBusses:
def setup(self):
"""Set up the model."""
# %% network setup
fluid_list = ['Ar', 'N2', 'O2', 'CO2', 'CH4', 'H2O']
self.nw = Network(fluids=fluid_list,
p_unit='bar',
T_unit='C',
p_range=[0.5, 20])
# %% components
amb = Source('ambient')
sf = Source('fuel')
cc = CombustionChamber('combustion')
cp = Compressor('compressor')
gt = Turbine('turbine')
fg = Sink('flue gas outlet')
# %% connections
amb_cp = Connection(amb, 'out1', cp, 'in1', label='ambient air flow')
cp_cc = Connection(cp, 'out1', cc, 'in1')
sf_cc = Connection(sf, 'out1', cc, 'in2')
cc_gt = Connection(cc, 'out1', gt, 'in1')
gt_fg = Connection(gt, 'out1', fg, 'in1')
self.nw.add_conns(amb_cp, cp_cc, sf_cc, cc_gt, gt_fg)
# %% component parameters
cc.set_attr(lamb=3)
cp.set_attr(eta_s=0.9, pr=15)
gt.set_attr(eta_s=0.9)
# %% connection parameters
amb_cp.set_attr(T=20,
p=1,
m=100,
fluid={
'Ar': 0.0129,
'N2': 0.7553,
'H2O': 0,
'CH4': 0,
'CO2': 0.0004,
'O2': 0.2314
})
sf_cc.set_attr(T=20,
fluid={
'CO2': 0.04,
'Ar': 0,
'N2': 0,
'O2': 0,
'H2O': 0,
'CH4': 0.96
})
gt_fg.set_attr(p=1)
# motor efficiency
x = np.array([
0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55,
0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15,
1.2, 10
])
y = np.array([
0.01, 0.3148, 0.5346, 0.6843, 0.7835, 0.8477, 0.8885, 0.9145,
0.9318, 0.9443, 0.9546, 0.9638, 0.9724, 0.9806, 0.9878, 0.9938,
0.9982, 0.999, 0.9995, 0.9999, 1, 0.9977, 0.9947, 0.9909, 0.9853,
0.9644
]) * 0.975
self.motor_bus_based = CharLine(x=x, y=y)
self.motor_comp_based = CharLine(x=x, y=1 / y)
# generator efficiency
x = np.array([
0.100, 0.345, 0.359, 0.383, 0.410, 0.432, 0.451, 0.504, 0.541,
0.600, 0.684, 0.805, 1.000, 1.700, 10
])
y = np.array([
0.976, 0.989, 0.990, 0.991, 0.992, 0.993, 0.994, 0.995, 0.996,
0.997, 0.998, 0.999, 1.000, 0.999, 0.99
]) * 0.975
self.generator = CharLine(x=x, y=y)
power_bus_total = Bus('total power output')
power_bus_total.add_comps(
{
'comp': cp,
'char': self.motor_bus_based,
'base': 'bus'
}, {
'comp': gt,
'char': self.generator
})
thermal_input = Bus('thermal input')
thermal_input.add_comps({'comp': cc})
compressor_power_comp = Bus('compressor power input')
compressor_power_comp.add_comps({
'comp': cp,
'char': self.motor_comp_based
})
compressor_power_bus = Bus('compressor power input bus based')
compressor_power_bus.add_comps({
'comp': cp,
'char': self.motor_bus_based,
'base': 'bus'
})
self.nw.add_busses(power_bus_total, thermal_input,
compressor_power_comp, compressor_power_bus)
# %% solving
self.nw.solve('design')
self.nw.save('tmp')
def test_model(self):
"""Test the bus functionalities in a gas turbine model."""
tpo = self.nw.busses['total power output']
ti = self.nw.busses['thermal input']
cpi = self.nw.busses['compressor power input']
cpibb = self.nw.busses['compressor power input bus based']
cp = self.nw.components['compressor']
gt = self.nw.components['turbine']
cc = self.nw.components['combustion']
# test results of design case
eta_cpi = round(1 / cp.calc_bus_efficiency(cpi), 6)
eta_cp_tpo = round(cp.calc_bus_efficiency(tpo), 6)
msg = ('The efficiency value of the compressor on the bus ' +
tpo.label + ' (' + str(eta_cp_tpo) +
') must be identical to the efficiency '
'on the bus ' + cpi.label + ' (' + str(eta_cpi) + ').')
assert eta_cp_tpo == eta_cpi, msg
P_cp_tpo = cp.calc_bus_value(tpo)
eta_cp_tpo = cp.calc_bus_efficiency(tpo)
P_cp = round(P_cp_tpo * eta_cp_tpo, 0)
msg = ('The compressor power must be ' + str(round(cp.P.val, 0)) +
' on '
'the bus ' + tpo.label + ' but is ' + str(P_cp) + ').')
assert round(cp.P.val, 0) == P_cp, msg
P_cp_tpo = round(
cp.calc_bus_value(tpo) * cp.calc_bus_efficiency(tpo), 0)
P_cp_cpi = round(
cp.calc_bus_value(cpi) / cp.calc_bus_efficiency(cpi), 0)
P_cp_cpibb = round(
cp.calc_bus_value(cpibb) * cp.calc_bus_efficiency(cpibb), 0)
msg = (
'The busses\' component power value for the compressor on bus ' +
tpo.label + ' (' + str(P_cp_tpo) + ') must be equal to the '
'component power on all other busses. Bus ' + cpi.label + ' (' +
str(P_cp_cpi) + ') and bus ' + cpibb.label + ' (' +
str(P_cp_cpibb) + ').')
assert P_cp_tpo == P_cp_cpi and P_cp_tpo == P_cp_cpibb, msg
eta_gt_tpo = gt.calc_bus_efficiency(tpo)
msg = ('The efficiency value of the turbine on the bus ' + tpo.label +
' (' + str(eta_gt_tpo) + ') must be equal to 0.975.')
assert eta_gt_tpo == 0.975, msg
eta_ti = cc.calc_bus_efficiency(ti)
msg = ('The efficiency value of the combustion chamber on the bus ' +
ti.label + ' (' + str(eta_ti) + ') must be equal to 1.0.')
assert eta_ti == 1.0, msg
# test partload for bus functions
# first test in identical conditions
self.nw.connections['ambient air flow'].set_attr(m=None)
P_design = cpibb.P.val
cpibb.set_attr(P=P_design)
self.nw.solve('offdesign', design_path='tmp')
eta_cpi = round(1 / cp.calc_bus_efficiency(cpi), 6)
eta_cp_tpo = round(cp.calc_bus_efficiency(tpo), 6)
msg = ('The efficiency value of the compressor on the bus ' +
tpo.label + ' (' + str(eta_cp_tpo) +
') must be identical to the efficiency '
'on the bus ' + cpi.label + ' (' + str(eta_cpi) + ').')
assert eta_cp_tpo == eta_cpi, msg
eta_gt_tpo = gt.calc_bus_efficiency(tpo)
msg = ('The efficiency value of the turbine on the bus ' + tpo.label +
' (' + str(eta_gt_tpo) + ') must be equal to 0.975.')
assert eta_gt_tpo == 0.975, msg
P_cp_tpo = round(
cp.calc_bus_value(tpo) * cp.calc_bus_efficiency(tpo), 0)
P_cp_cpi = round(
cp.calc_bus_value(cpi) / cp.calc_bus_efficiency(cpi), 0)
P_cp_cpibb = round(
cp.calc_bus_value(cpibb) * cp.calc_bus_efficiency(cpibb), 0)
msg = (
'The busses\' component power value for the compressor on bus ' +
tpo.label + ' (' + str(P_cp_tpo) + ') must be equal to the '
'component power on all other busses. Bus ' + cpi.label + ' (' +
str(P_cp_cpi) + ') and bus ' + cpibb.label + ' (' +
str(P_cp_cpibb) + ').')
assert P_cp_tpo == P_cp_cpi and P_cp_tpo == P_cp_cpibb, msg
# 60 % load
load = 0.6
cpibb.set_attr(P=P_design * load)
self.nw.solve('offdesign', design_path='tmp')
eta_cp_tpo = round(cp.calc_bus_efficiency(tpo), 6)
eta_cp_char = self.motor_bus_based.evaluate(load)
msg = ('The efficiency value of the compressor on the bus ' +
tpo.label + ' (' + str(eta_cp_tpo) +
') must be identical to the efficiency '
'on the characteristic line (' + str(eta_cp_char) + ').')
assert eta_cp_tpo == eta_cp_char, msg
load_frac = round(
cp.calc_bus_value(tpo) / tpo.comps.loc[cp, 'P_ref'], 6)
msg = ('The load fraction value of the compressor on the bus ' +
tpo.label + ' (' + str(load_frac) +
') must be identical to the '
'load fraction value on the bus ' + cpibb.label + ' (' +
str(load) + ').')
assert load == load_frac, msg
eta_cpi = round(1 / cp.calc_bus_efficiency(cpi), 6)
eta_cp_tpo = round(cp.calc_bus_efficiency(tpo), 6)
msg = ('The efficiency value of the compressor on the bus ' +
tpo.label + ' (' + str(eta_cp_tpo) +
') must be higher than the efficiency '
'on the bus ' + cpi.label + ' (' + str(eta_cpi) + ').')
assert eta_cp_tpo > eta_cpi, msg
P_cp_tpo = round(
cp.calc_bus_value(tpo) * cp.calc_bus_efficiency(tpo), 0)
P_cp_cpi = round(
cp.calc_bus_value(cpi) / cp.calc_bus_efficiency(cpi), 0)
P_cp_cpibb = round(
cp.calc_bus_value(cpibb) * cp.calc_bus_efficiency(cpibb), 0)
msg = (
'The busses\' component power value for the compressor on bus ' +
tpo.label + ' (' + str(P_cp_tpo) + ') must be equal to the '
'component power on all other busses. Bus ' + cpi.label + ' (' +
str(P_cp_cpi) + ') and bus ' + cpibb.label + ' (' +
str(P_cp_cpibb) + ').')
assert P_cp_tpo == P_cp_cpi and P_cp_tpo == P_cp_cpibb, msg
shutil.rmtree('tmp', ignore_errors=True)
