def test_exergy_analysis_missing_E_F_E_P_information(self):
"""Test exergy analysis errors with missing information."""
with raises(TESPyNetworkError):
ExergyAnalysis(self.nw, E_P=[self.power], E_F=[])
with raises(TESPyNetworkError):
ExergyAnalysis(self.nw, E_P=[], E_F=[self.heat])
def test_exergy_analysis_component_on_two_busses(self):
"""Test exergy analysis errors with components on more than one bus."""
with raises(TESPyNetworkError):
ean = ExergyAnalysis(self.nw,
E_P=[self.power],
E_F=[self.heat, self.power])
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
def test_exergy_analysis_violated_balance(self):
"""Test exergy analysis with violated balance."""
# specify efficiency values for the internal bus
self.nw.del_busses(self.fwp_power)
self.fwp_power = Bus('feed water pump power', P=0)
self.fwp_power.add_comps(
{
'comp': self.nw.get_comp('feed water pump turbine'),
'char': 0.99
}, {
'comp': self.nw.get_comp('pump'),
'char': 0.98,
'base': 'bus'
})
self.nw.add_busses(self.fwp_power)
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
# miss out on internal bus in exergy_analysis
ean = ExergyAnalysis(self.nw, E_P=[self.power], E_F=[self.heat])
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
exergy_balance = (ean.network_data.E_F - ean.network_data.E_P -
ean.network_data.E_L - ean.network_data.E_D)
msg = ('Exergy balance must be violated for this test (larger than ' +
str(err**0.5) + ') but is ' +
str(round(abs(exergy_balance), 4)) + ' .')
assert abs(exergy_balance) > err**0.5, msg
def test_exergy_analysis_perfect_cycle(self):
"""Test exergy analysis in the perfect clausius rankine cycle."""
ean = ExergyAnalysis(self.nw,
E_P=[self.power],
E_F=[self.heat],
internal_busses=[self.fwp_power])
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
msg = ('Exergy destruction of this network must be 0 (smaller than ' +
str(err**0.5) + ') for this test but is ' +
str(round(abs(ean.network_data.E_D), 4)) + ' .')
assert abs(ean.network_data.E_D) <= err**0.5, msg
msg = ('Exergy efficiency of this network must be 1 for this test but '
'is ' + str(round(ean.network_data.epsilon, 4)) + ' .')
assert round(ean.network_data.epsilon, 4) == 1, msg
exergy_balance = (ean.network_data.E_F - ean.network_data.E_P -
ean.network_data.E_L - ean.network_data.E_D)
msg = ('Exergy balance must be closed (residual value smaller than ' +
str(err**0.5) + ') for this test but is ' +
str(round(abs(exergy_balance), 4)) + ' .')
assert abs(exergy_balance) <= err**0.5, msg
msg = (
'Fuel exergy and product exergy must be identical for this test. '
'Fuel exergy value: ' + str(round(ean.network_data.E_F, 4)) +
'. Product exergy value: ' + str(round(ean.network_data.E_P, 4)) +
'.')
delta = round(abs(ean.network_data.E_F - ean.network_data.E_P), 4)
assert delta < err**0.5, msg
def test_exergy_analysis_plotting_data(self):
"""Test exergy analysis plotting."""
self.nw.get_comp('steam generator').set_attr(pr=0.9)
self.nw.get_comp('turbine').set_attr(eta_s=0.9)
self.nw.get_comp('feed water pump turbine').set_attr(eta_s=0.85)
self.nw.get_comp('pump').set_attr(eta_s=0.75)
self.nw.get_conn('cond').set_attr(T=self.Tamb + 3)
# specify efficiency values for the internal bus and power bus
self.nw.del_busses(self.fwp_power, self.power)
self.fwp_power = Bus('feed water pump power', P=0)
self.fwp_power.add_comps(
{
'comp': self.nw.get_comp('feed water pump turbine'),
'char': 0.99
}, {
'comp': self.nw.get_comp('pump'),
'char': 0.98,
'base': 'bus'
})
self.power = Bus('power_output')
self.power.add_comps({
'comp': self.nw.get_comp('turbine'),
'char': 0.98
})
self.nw.add_busses(self.fwp_power, self.power)
# solve network
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
ean = ExergyAnalysis(self.nw,
E_P=[self.power],
E_F=[self.heat],
internal_busses=[self.fwp_power])
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
exergy_balance = (ean.network_data.E_F - ean.network_data.E_P -
ean.network_data.E_L - ean.network_data.E_D)
msg = ('Exergy balance must be closed (residual value smaller than ' +
str(err**0.5) + ') for this test but is ' +
str(round(abs(exergy_balance), 4)) + ' .')
assert abs(exergy_balance) <= err**0.5, msg
nodes = [
'E_F', 'steam generator', 'splitter 1', 'feed water pump turbine',
'turbine', 'merge 1', 'condenser', 'pump', 'E_D', 'E_P'
]
links, nodes = ean.generate_plotly_sankey_input(node_order=nodes)
# checksum for targets and source
checksum = sum(links['target'] + links['source'])
msg = ('The checksum of all target and source values in the link lists'
'must be 148, but is ' + str(checksum) + '.')
assert 148 == checksum, msg
def test_exergy_analysis_bus_conversion(self):
"""Test exergy analysis at product exergy with T < Tamb."""
ean = ExergyAnalysis(self.nw, E_P=[self.cas_in], E_F=[self.power_in])
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
exergy_balance = (ean.network_data.E_F - ean.network_data.E_P -
ean.network_data.E_L - ean.network_data.E_D)
msg = ('Exergy balance must be closed (residual value smaller than ' +
str(err**0.5) + ') for this test but is ' +
str(round(abs(exergy_balance), 4)) + ' .')
assert abs(exergy_balance) <= err**0.5, msg
def test_exergy_analysis(self):
"""Test the exergy analysis results."""
# carry out exergy analysis
ean = ExergyAnalysis(self.nw,
E_P=[self.nw.busses['total output power']],
E_F=[self.nw.busses['heat input']],
E_L=[self.nw.busses['exergy loss']])
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
# generate Grassmann diagram
links, nodes = ean.generate_plotly_sankey_input()
# check if exergy product value in links is equal to total power
# output
position = links['target'].index(nodes.index('E_P'))
power_links = round(links['value'][position], 0)
power_bus = round(-self.nw.busses['total output power'].P.val, 0)
msg = ('The exergy product value in the links (' + str(power_links) +
') must be equal to the power on the respective bus (' +
str(power_bus) + ').')
assert power_links == power_bus, msg
def test_exergy_analysis_bus_conversion(self):
"""Test exergy analysis at product exergy with T < Tamb."""
ean = ExergyAnalysis(self.nw,
E_P=[self.power_out],
E_F=[self.cas_out],
E_L=[self.ex_loss])
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
exergy_balance = (ean.network_data.E_F - ean.network_data.E_P -
ean.network_data.E_L - ean.network_data.E_D)
msg = ('Exergy balance must be closed (residual value smaller than ' +
str(err**0.5) + ') for this test but is ' +
str(round(abs(exergy_balance), 4)) + '.')
assert abs(exergy_balance) <= err**0.5, msg
msg = ('Exergy efficiency must be equal to 1.0 for this test but is ' +
str(round(ean.network_data.epsilon, 4)) + '.')
assert round(ean.network_data.epsilon, 4) == 1, msg
c = self.nw.get_conn('outlet')
c.set_attr(T=self.Tamb - 20)
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
msg = (
'Exergy destruction must be equal to 0.0 for this test but is ' +
str(round(ean.network_data.E_D, 4)) + '.')
assert round(ean.network_data.E_D, 4) == 0, msg
msg = ('Exergy loss must be equal to ' + str(round(c.Ex_physical, 4)) +
' for this test but is ' + str(round(ean.network_data.E_L, 4)) +
'.')
assert round(ean.network_data.E_L, 4) == round(c.Ex_physical, 4), msg
def run_analysis(self):
ean = ExergyAnalysis(self.nw,
E_P=[self.exergy_prod],
E_F=[self.exergy_fuel])
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
exergy_balance = (ean.network_data.E_F - ean.network_data.E_P -
ean.network_data.E_L - ean.network_data.E_D)
msg = ('Exergy balance must be closed (residual value smaller than ' +
str(err**0.5) + ') for this test but is ' +
str(round(abs(exergy_balance), 4)) + '.')
assert abs(exergy_balance) <= err**0.5, msg
E_D_agg = ean.aggregation_data['E_D'].sum()
E_D_nw = ean.network_data.loc['E_D']
msg = ('The exergy destruction of the aggregated components and '
'respective busses (' + str(round(E_D_agg)) +
') must be equal to '
'the exergy destruction of the network (' + str(round(E_D_nw)) +
').')
assert E_D_agg == E_D_nw, msg
def test_exergy_analysis_bus_conversion(self):
"""Test exergy analysis bus conversion factors."""
# specify efficiency values for the internal bus
self.nw.del_busses(self.fwp_power)
self.fwp_power = Bus('feed water pump power', P=0)
self.fwp_power.add_comps(
{
'comp': self.nw.get_comp('feed water pump turbine'),
'char': 0.99
}, {
'comp': self.nw.get_comp('pump'),
'char': 0.98,
'base': 'bus'
})
self.nw.add_busses(self.fwp_power)
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
# no exergy losses in this case
ean = ExergyAnalysis(self.nw,
E_P=[self.power],
E_F=[self.heat],
internal_busses=[self.fwp_power])
ean.analyse(pamb=self.pamb, Tamb=self.Tamb)
label = 'pump'
eps = ean.bus_data.loc[label, 'epsilon']
msg = ('Pump exergy efficiency must be 0.98 but is ' +
str(round(eps, 4)) + ' .')
assert round(eps, 4) == 0.98, msg
label = 'feed water pump turbine'
eps = ean.bus_data.loc[label, 'epsilon']
msg = (
'Feed water pump turbine exergy efficiency must be 0.99 but is ' +
str(round(eps, 4)) + ' .')
assert round(eps, 4) == 0.99, msg
result_dict[key]['datapoints'] = diagram.calc_individual_isoline(**data)
diagram.set_limits(x_min=200, x_max=500, y_min=0.8e1, y_max=0.8e2)
diagram.calc_isolines()
diagram.draw_isolines('logph')
for key in result_dict.keys():
datapoints = result_dict[key]['datapoints']
diagram.ax.plot(datapoints['h'], datapoints['p'], color='#ff0000')
diagram.ax.scatter(datapoints['h'][0], datapoints['p'][0], color='#ff0000')
diagram.save('R410A_logph.svg')
# %% exergy analysis
ean = ExergyAnalysis(network=nw, E_F=[power, heat_geo], E_P=[heat_cons])
ean.analyse(pamb, Tamb)
print("\n##### EXERGY ANALYSIS #####\n")
ean.print_results()
# create sankey diagram
links, nodes = ean.generate_plotly_sankey_input()
fig = go.Figure(
go.Sankey(arrangement="snap",
node={
"label": nodes,
'pad': 11,
'color': 'orange'
},
link=links))
plot(fig, filename='R410A_sankey.html')