class PowerPlant():
def __init__(self, working_fluid):
"""Set up model."""
self.working_fluid = working_fluid
fluids = ['water', self.working_fluid, 'air']
self.nw = Network(fluids=fluids)
self.nw.set_attr(p_unit='bar', T_unit='C', h_unit='kJ / kg')
# geo parameters
self.geo_mass_flow = 200
geo_steam_share = 0.1
self.T_brine_in = 140
# ambient parameters
self.T_amb = 5
self.p_amb = 0.6
# main components
geo_steam = Source('geosteam source')
geo_brine = Source('geobrine source')
geo_reinjection = Sink('re-injection')
air_in = Source('air source')
air_out = Sink('air sink')
air_fan = Compressor('air fan')
air_cond = Condenser('condenser')
orc_cc = CycleCloser('orc cycle closer')
evap_splitter = Splitter('splitter evaporation')
evap_merge = Merge('merge evaporation')
evap_steam = Condenser('geosteam evaporator')
evap_brine = HeatExchanger('geobrine evaporator')
dr = Drum('drum')
geo_merge = Merge('merge brine')
pre = HeatExchanger('preheater')
feed_working_fluid_pump = Pump('feed pump')
tur = Turbine('turbine')
ihe = HeatExchanger('internal heat exchanger')
# busses
net_power = Bus('net power output')
net_power.add_comps(
{'comp': tur, 'char': 0.97},
{'comp': feed_working_fluid_pump, 'char': 0.97, 'base': 'bus'},
{'comp': air_fan, 'char': 0.97, 'base': 'bus'}
)
ORC_power_bus = Bus('cycle gross power output')
ORC_power_bus.add_comps(
{'comp': tur}, {'comp': feed_working_fluid_pump}
)
geothermal_bus = Bus('thermal input')
geothermal_bus.add_comps(
{'comp': pre, 'char': -1}, {'comp': evap_brine, 'char': -1},
{'comp': evap_steam, 'char': -1}
)
self.nw.add_busses(net_power, ORC_power_bus, geothermal_bus)
# turbine to condenser
c1 = Connection(orc_cc, 'out1', tur, 'in1', label='1')
c2 = Connection(tur, 'out1', ihe, 'in1', label='2')
c3 = Connection(ihe, 'out1', air_cond, 'in1', label='3')
self.nw.add_conns(c1, c2, c3)
# condenser to steam generator
c4 = Connection(air_cond, 'out1', feed_working_fluid_pump, 'in1', label='4')
c5 = Connection(feed_working_fluid_pump, 'out1', ihe, 'in2', label='5')
self.nw.add_conns(c4, c5)
# steam generator
c6 = Connection(ihe, 'out2', pre, 'in2', label='6')
c7 = Connection(pre, 'out2', dr, 'in1', label='7')
c8 = Connection(dr, 'out1', evap_splitter, 'in1', label='8')
c9 = Connection(evap_splitter, 'out2', evap_steam, 'in2', label='9')
c10 = Connection(evap_steam, 'out2', evap_merge, 'in2', label='10')
c11 = Connection(evap_splitter, 'out1', evap_brine, 'in2', label='11')
c12 = Connection(evap_brine, 'out2', evap_merge, 'in1', label='12')
c13 = Connection(evap_merge, 'out1', dr, 'in2', label='13')
c0 = Connection(dr, 'out2', orc_cc, 'in1', label='0')
self.nw.add_conns(c6, c7, c8, c11, c9, c12, c10, c13, c0)
# condenser cold side
c20 = Connection(air_in, 'out1', air_fan, 'in1', label='20')
c21 = Connection(air_fan, 'out1', air_cond, 'in2', label='21')
c22 = Connection(air_cond, 'out2', air_out, 'in1', label='22')
self.nw.add_conns(c20, c21, c22)
# geo source
c30 = Connection(geo_steam, 'out1', evap_steam, 'in1', label='30')
c31 = Connection(evap_steam, 'out1', geo_merge, 'in1', label='31')
c32 = Connection(geo_brine, 'out1', geo_merge, 'in2', label='32')
c33 = Connection(geo_merge, 'out1', evap_brine, 'in1', label='33')
self.nw.add_conns(c30, c31, c32, c33)
c34 = Connection(evap_brine, 'out1', pre, 'in1', label='34')
c35 = Connection(pre, 'out1', geo_reinjection, 'in1', label='35')
self.nw.add_conns(c34, c35)
# generate a set of stable starting values of every working fluid
# fluid settings
c6.set_attr(fluid={self.working_fluid: 1.0, 'air': 0.0, 'water': 0.0})
c20.set_attr(fluid={self.working_fluid: 0.0, 'air': 1.0, 'water': 0.0})
c30.set_attr(fluid={self.working_fluid: 0.0, 'air': 0.0, 'water': 1.0})
c32.set_attr(fluid={self.working_fluid: 0.0, 'air': 0.0, 'water': 1.0})
# connection parameters
p0 = PSI('P', 'T', self.T_brine_in + 273.15, 'Q', 1, self.working_fluid)
c1.set_attr(p0=p0 / 1e5)
ws_stable_h0 = (
PSI('H', 'T', self.T_amb + 273.15, 'Q', 1, self.working_fluid) +
0.5 * (
PSI('H', 'T', self.T_brine_in + 273.15, 'Q', 1, self.working_fluid) -
PSI('H', 'T', self.T_amb + 273.15, 'Q', 1, self.working_fluid)
)
) / 1e3
c2.set_attr(h=ws_stable_h0)
p0 = PSI('P', 'T', self.T_amb + 273.15, 'Q', 1, self.working_fluid)
c3.set_attr(Td_bp=5, design=['Td_bp'], p0=p0 / 1e5)
c5.set_attr(h=Ref(c4, 1, 1))
# steam generator
c30.set_attr(
m=self.geo_mass_flow * geo_steam_share,
T=self.T_brine_in, x=1, p0=5)
c32.set_attr(
m=self.geo_mass_flow * (1 - geo_steam_share),
T=self.T_brine_in, x=0)
c13.set_attr()
c12.set_attr(x=0.5)
c10.set_attr(x=0.5, design=['x'])
c34.set_attr(h=Ref(c33, 1, -50))
c7.set_attr(Td_bp=-2)
# main condenser
c20.set_attr(p=self.p_amb, T=self.T_amb)
c22.set_attr(T=self.T_amb + 15, p=self.p_amb)
# component parameters
# condensing
ihe.set_attr(pr1=0.98, pr2=0.98)
air_cond.set_attr(pr1=1, pr2=0.995, ttd_u=10)
air_fan.set_attr(eta_s=0.6)
# steam generator
evap_brine.set_attr(pr1=0.98, ttd_l=8)
pre.set_attr(pr1=0.98, pr2=0.98)
self.nw.set_attr(iterinfo=False)
self.nw.solve('design')
self.nw.save('stable_' + self.working_fluid)
# specify actual parameters
tur.set_attr(eta_s=0.9)
feed_working_fluid_pump.set_attr(eta_s=0.75)
c2.set_attr(h=None)
c5.set_attr(h=None)
c34.set_attr(h=None, T=Ref(c33, 1, -10))
self.nw.solve('design')
c22.set_attr(T=None)
c3.set_attr(Td_bp=None)
self.ude_IHE_size = UserDefinedEquation(
label='ihe deshuperheat ratio',
func=desuperheat, deriv=desuperheat_deriv,
latex={
'equation':
r'0 = h_3 - h_2 - x_\mathrm{IHE} \cdot \left(h_3 -'
r'h\left(p_2, T_5 + \Delta T_\mathrm{t,u,min} \right)'
r'\right)'},
conns=[
self.nw.get_conn('2'),
self.nw.get_conn('3'),
self.nw.get_conn('5')],
params={'distance': 0.0, 'ttd_min': 2}
)
if self.nw.lin_dep or self.nw.res[-1] > 1e-3:
msg = 'No stable solution found.'
raise TESPyNetworkError(msg)
print(
'Generated stable starting values for working fluid ' +
self.working_fluid + '.')
def run_simulation(
self, p_before_tur=None, Q_ihe=None, Q_brine_ev=None,
T_before_tur=None, T_reinjection=None, brine_evap_Td=None,
dT_air=None, IHE_sizing=None, geo_steam_share=None):
"""Run simulation on specified parameter set."""
self.nw.get_comp('internal heat exchanger').set_attr(Q=Q_ihe)
self.nw.get_conn('1').set_attr(p=p_before_tur, T=T_before_tur)
self.nw.get_conn('35').set_attr(T=T_reinjection)
self.nw.get_comp('geobrine evaporator').set_attr(Q=Q_brine_ev)
if geo_steam_share is not None:
self.nw.get_conn('30').set_attr(
m=self.geo_mass_flow * geo_steam_share)
self.nw.get_conn('32').set_attr(
m=self.geo_mass_flow * (1 - geo_steam_share))
if brine_evap_Td is not None:
self.nw.get_conn('34').set_attr(
T=Ref(self.nw.get_conn('33'), 1, brine_evap_Td))
else:
self.nw.get_conn('34').set_attr(T=None)
if dT_air is not None:
self.nw.get_conn('22').set_attr(T=Ref(self.nw.get_conn('21'), 1, dT_air))
else:
self.nw.get_conn('22').set_attr(T=None)
if IHE_sizing is None:
if self.ude_IHE_size in self.nw.user_defined_eq.values():
self.nw.del_ude(self.ude_IHE_size)
self.nw.get_comp('internal heat exchanger').set_attr(pr1=0.98, pr2=0.98)
else:
if self.ude_IHE_size not in self.nw.user_defined_eq.values():
self.nw.add_ude(self.ude_IHE_size)
self.ude_IHE_size.params['distance'] = IHE_sizing
if IHE_sizing == 0:
self.nw.get_comp('internal heat exchanger').set_attr(pr1=1, pr2=1)
else:
self.nw.get_comp('internal heat exchanger').set_attr(pr1=0.98, pr2=0.98)
try:
self.nw.solve('design')
# self.nw.print_results()
except ValueError:
self.nw.res = [1]
pass
def check_simulation(self, value):
"""Check if simulation converged."""
if self.nw.lin_dep or self.nw.res[-1] > 1e-3:
self.nw.solve(
'design', init_path='stable_' + self.working_fluid,
init_only=True)
return np.nan
else:
for cp in self.nw.comps['object']:
if isinstance(cp, HeatExchanger):
if cp.Q.val > 0:
print(cp.label)
return np.nan
elif cp.kA.val <= 0 or (np.isnan(cp.kA.val) and cp.Q.val != 0):
print(cp.label)
return np.nan
return value
def get_power(self):
"""Calculate ORC gross power (main cycle only)."""
return self.check_simulation(self.nw.busses['cycle gross power output'].P.val)
def get_net_power(self):
"""Calculate net power."""
return self.check_simulation(self.nw.busses['net power output'].P.val)
def get_thermal_efficiency(self):
"""Calculate thermal efficiency."""
return self.check_simulation(
-self.nw.busses['cycle gross power output'].P.val /
self.nw.busses['thermal input'].P.val)
def get_net_efficiency(self):
"""Calculate net efficiency."""
return self.check_simulation(
-self.nw.busses['net power output'].P.val /
self.nw.busses['thermal input'].P.val)
def get_geosteam_share(self):
"""Return a geosteam share."""
return self.check_simulation(
self.nw.get_conn('geosteam').m.val_SI / self.geo_mass_flow)
def get_connection_param(self, conn, param):
"""Return a connection parameter."""
return self.check_simulation(
self.nw.get_conn(conn).get_attr(param).val)
def get_component_param(self, comp, param):
"""Return a component parameter."""
return self.check_simulation(
self.nw.get_comp(comp).get_attr(param).val)
def get_misc_param(self, param):
"""Get non component or connection parameters."""
if param == 'gross power output':
return self.get_power()
elif param == 'net power output':
return self.get_net_power()
elif param == 'thermal efficiency':
return self.get_thermal_efficiency()
elif param == 'net efficiency':
return self.get_net_efficiency()
elif param == 'IHE sizing factor':
return self.ude_IHE_size.params['distance']
def get_objective_func(self, objective):
"""Return corresponding objective function."""
if objective == 'net power output':
return self.get_net_power
elif objective == 'gross power output':
return self.get_power
else:
msg = (
'Please specify valid objective function: "net power output" '
'or "gross power output".')
raise ValueError(msg)
class TestFluidPropertyBackEnds:
"""Testing full models with different fluid property back ends."""
def setup_clausius_rankine(self, fluid_list):
"""Setup a Clausius-Rankine cycle."""
self.nw = Network(fluids=fluid_list)
self.nw.set_attr(p_unit='bar', T_unit='C', iterinfo=True)
# %% components
# main components
turb = Turbine('turbine')
con = Condenser('condenser')
pu = Pump('pump')
steam_generator = HeatExchangerSimple('steam generator')
closer = CycleCloser('cycle closer')
# cooling water
so_cw = Source('cooling water inlet')
si_cw = Sink('cooling water outlet')
# %% connections
# main cycle
fs_in = Connection(closer, 'out1', turb, 'in1', label='livesteam')
ws = Connection(turb, 'out1', con, 'in1', label='wastesteam')
cond = Connection(con, 'out1', pu, 'in1', label='condensate')
fw = Connection(pu, 'out1', steam_generator, 'in1', label='feedwater')
fs_out = Connection(steam_generator, 'out1', closer, 'in1')
self.nw.add_conns(fs_in, ws, cond, fw, fs_out)
# cooling water
cw_in = Connection(so_cw, 'out1', con, 'in2')
cw_out = Connection(con, 'out2', si_cw, 'in1')
self.nw.add_conns(cw_in, cw_out)
# %% parametrization of components
turb.set_attr(eta_s=0.9)
con.set_attr(pr1=1, pr2=0.99, ttd_u=5)
steam_generator.set_attr(pr=0.9)
# %% parametrization of connections
fs_in.set_attr(p=100, T=500, m=100, fluid={self.nw.fluids[0]: 1})
fw.set_attr(h=200e3)
cw_in.set_attr(T=20, p=5, fluid={self.nw.fluids[0]: 1})
cw_out.set_attr(T=30)
# %% solving
self.nw.solve('design')
pu.set_attr(eta_s=0.7)
fw.set_attr(h=None)
self.nw.solve('design')
def setup_pipeline_network(self, fluid_list):
"""Setup a pipeline network."""
self.nw = Network(fluids=fluid_list)
self.nw.set_attr(p_unit='bar', T_unit='C', iterinfo=False)
# %% components
# main components
pu = Pump('pump')
pi = Pipe('pipeline')
es = HeatExchangerSimple('energy balance closing')
closer = CycleCloser('cycle closer')
pu_pi = Connection(pu, 'out1', pi, 'in1')
pi_es = Connection(pi, 'out1', es, 'in1')
es_closer = Connection(es, 'out1', closer, 'in1')
closer_pu = Connection(closer, 'out1', pu, 'in1')
self.nw.add_conns(pu_pi, pi_es, es_closer, closer_pu)
# %% parametrization of components
pu.set_attr(eta_s=0.7)
pi.set_attr(pr=0.95, L=100, ks=1e-5, D='var', Q=0)
es.set_attr(pr=1)
# %% parametrization of connections
pu_pi.set_attr(p=20, T=100, m=10, fluid={self.nw.fluids[0]: 1})
# %% solving
self.nw.solve('design')
@pytest.mark.skipif(
os.environ.get('TRAVIS') == 'true',
reason='Travis CI cannot handle the tabular CoolProp back ends, '
'skipping this test. The test should run on your local machine.')
def test_clausius_rankine_tabular(self):
"""Test the Clausius-Rankine cycle with different back ends."""
fluid = 'water'
back_ends = ['HEOS', 'BICUBIC', 'TTSE']
results = {}
for back_end in back_ends:
# delete the fluid from the memorisation class
if fluid in fp.Memorise.state.keys():
del fp.Memorise.state[fluid]
del fp.Memorise.back_end[fluid]
self.setup_clausius_rankine([back_end + '::' + fluid])
results[back_end] = (
1 - abs(self.nw.get_comp('condenser').Q.val) /
self.nw.get_comp('steam generator').Q.val)
efficiency = results['HEOS']
if fluid in fp.Memorise.state.keys():
del fp.Memorise.state[fluid]
del fp.Memorise.back_end[fluid]
for back_end in back_ends:
if back_end == 'HEOS':
continue
d_rel = (abs(results[back_end] - efficiency) / efficiency)
msg = (
'The deviation in thermal efficiency of the Clausius-Rankine '
'cycle calculated with ' + back_end + ' back end is ' +
str(d_rel) + ' but should not be larger than 1e-4.')
assert d_rel <= 1e-4, msg
def test_clausius_rankine(self):
"""Test the Clausius-Rankine cycle with different back ends."""
fluid = 'water'
back_ends = ['HEOS', 'IF97']
results = {}
for back_end in back_ends:
# delete the fluid from the memorisation class
if fluid in fp.Memorise.state.keys():
del fp.Memorise.state[fluid]
del fp.Memorise.back_end[fluid]
self.setup_clausius_rankine([back_end + '::' + fluid])
results[back_end] = (
1 - abs(self.nw.get_comp('condenser').Q.val) /
self.nw.get_comp('steam generator').Q.val)
efficiency = results['HEOS']
if fluid in fp.Memorise.state.keys():
del fp.Memorise.state[fluid]
del fp.Memorise.back_end[fluid]
for back_end in back_ends:
if back_end == 'HEOS':
continue
d_rel = (abs(results[back_end] - efficiency) / efficiency)
msg = (
'The deviation in thermal efficiency of the Clausius-Rankine '
'cycle calculated with ' + back_end + ' back end is ' +
str(d_rel) + ' but should not be larger than 1e-4.')
assert d_rel <= 1e-4, msg
def test_pipeline_network(self):
"""Test a pipeline network with fluids from different back ends."""
fluids_back_ends = {'DowJ': 'INCOMP', 'water': 'HEOS'}
for fluid, back_end in fluids_back_ends.items():
# delete the fluid from the memorisation class
if fluid in fp.Memorise.state.keys():
del fp.Memorise.state[fluid]
self.setup_pipeline_network([back_end + '::' + fluid])
convergence_check(self.nw.lin_dep)
value = round(self.nw.get_comp('pipeline').pr.val, 5)
msg = (
'The pressure ratio of the pipeline must be at 0.95, but '
'is at ' + str(value) + ' for the fluid ' + fluid + '.')
assert value == 0.95, msg
value = round(self.nw.get_comp('pump').pr.val, 5)
msg = (
'The pressure ratio of the pipeline must be at ' +
str(round(1 / 0.95, 5)) + ', but is at ' + str(value) +
' for the fluid ' + fluid + '.')
assert value == round(1 / 0.95, 5), msg
class TestClausiusRankine:
def setup(self):
"""Set up clausis rankine cycle with turbine driven feed water pump."""
self.Tamb = 20
self.pamb = 1
fluids = ['water']
self.nw = Network(fluids=fluids)
self.nw.set_attr(p_unit='bar', T_unit='C', h_unit='kJ / kg')
# create components
splitter1 = Splitter('splitter 1')
merge1 = Merge('merge 1')
turb = Turbine('turbine')
fwp_turb = Turbine('feed water pump turbine')
condenser = HeatExchangerSimple('condenser')
fwp = Pump('pump')
steam_generator = HeatExchangerSimple('steam generator')
cycle_close = CycleCloser('cycle closer')
# create busses
# power output bus
self.power = Bus('power_output')
self.power.add_comps({'comp': turb, 'char': 1})
# turbine driven feed water pump internal bus
self.fwp_power = Bus('feed water pump power', P=0)
self.fwp_power.add_comps({
'comp': fwp_turb,
'char': 1
}, {
'comp': fwp,
'char': 1,
'base': 'bus'
})
# heat input bus
self.heat = Bus('heat_input')
self.heat.add_comps({'comp': steam_generator, 'base': 'bus'})
self.nw.add_busses(self.power, self.fwp_power, self.heat)
# create connections
fs_in = Connection(cycle_close, 'out1', splitter1, 'in1', label='fs')
fs_fwpt = Connection(splitter1, 'out1', fwp_turb, 'in1')
fs_t = Connection(splitter1, 'out2', turb, 'in1')
fwpt_ws = Connection(fwp_turb, 'out1', merge1, 'in1')
t_ws = Connection(turb, 'out1', merge1, 'in2')
ws = Connection(merge1, 'out1', condenser, 'in1')
cond = Connection(condenser, 'out1', fwp, 'in1', label='cond')
fw = Connection(fwp, 'out1', steam_generator, 'in1', label='fw')
fs_out = Connection(steam_generator, 'out1', cycle_close, 'in1')
self.nw.add_conns(fs_in, fs_fwpt, fs_t, fwpt_ws, t_ws, ws, cond, fw,
fs_out)
# component parameters
turb.set_attr(eta_s=1)
fwp_turb.set_attr(eta_s=1)
condenser.set_attr(pr=1)
fwp.set_attr(eta_s=1)
steam_generator.set_attr(pr=1)
# connection parameters
fs_in.set_attr(m=10, p=120, T=600, fluid={'water': 1})
cond.set_attr(T=self.Tamb, x=0)
# solve network
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
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_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_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
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)
class TestClausiusRankine:
def setup(self):
"""Set up clausis rankine cycle with turbine driven feed water pump."""
self.Tamb = 20
self.pamb = 1
fluids = ['water']
self.nw = Network(fluids=fluids)
self.nw.set_attr(p_unit='bar', T_unit='C', h_unit='kJ / kg')
# create components
splitter1 = Splitter('splitter 1')
merge1 = Merge('merge 1')
turb = Turbine('turbine')
fwp_turb = Turbine('feed water pump turbine')
condenser = HeatExchangerSimple('condenser')
fwp = Pump('pump')
steam_generator = HeatExchangerSimple('steam generator')
cycle_close = CycleCloser('cycle closer')
# create busses
# power output bus
self.power = Bus('power_output')
self.power.add_comps({'comp': turb, 'char': 1})
# turbine driven feed water pump internal bus
self.fwp_power = Bus('feed water pump power', P=0)
self.fwp_power.add_comps({
'comp': fwp_turb,
'char': 1
}, {
'comp': fwp,
'char': 1,
'base': 'bus'
})
# heat input bus
self.heat = Bus('heat_input')
self.heat.add_comps({'comp': steam_generator, 'base': 'bus'})
self.nw.add_busses(self.power, self.fwp_power, self.heat)
# create connections
fs_in = Connection(cycle_close, 'out1', splitter1, 'in1', label='fs')
fs_fwpt = Connection(splitter1, 'out1', fwp_turb, 'in1')
fs_t = Connection(splitter1, 'out2', turb, 'in1')
fwpt_ws = Connection(fwp_turb, 'out1', merge1, 'in1')
t_ws = Connection(turb, 'out1', merge1, 'in2')
ws = Connection(merge1, 'out1', condenser, 'in1')
cond = Connection(condenser, 'out1', fwp, 'in1', label='cond')
fw = Connection(fwp, 'out1', steam_generator, 'in1', label='fw')
fs_out = Connection(steam_generator, 'out1', cycle_close, 'in1')
self.nw.add_conns(fs_in, fs_fwpt, fs_t, fwpt_ws, t_ws, ws, cond, fw,
fs_out)
# component parameters
turb.set_attr(eta_s=1)
fwp_turb.set_attr(eta_s=1)
condenser.set_attr(pr=1)
fwp.set_attr(eta_s=1)
steam_generator.set_attr(pr=1)
# connection parameters
fs_in.set_attr(m=10, p=120, T=600, fluid={'water': 1})
cond.set_attr(T=self.Tamb, x=0)
# solve network
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
def test_entropy_perfect_cycle(self):
"""Test entropy values in the perfect clausius rankine cycle."""
labels = [
'turbine', 'feed water pump turbine', 'condenser',
'steam generator', 'pump'
]
for label in labels:
cp = self.nw.get_comp(label)
msg = (
'Entropy production due to irreversibility must be 0 for all '
'components in this test but is ' + str(round(cp.S_irr, 4)) +
' at component ' + label + ' of type ' + cp.component() + '.')
assert round(cp.S_irr, 4) == 0, msg
sg = self.nw.get_comp('steam generator')
cd = self.nw.get_comp('condenser')
msg = (
'Value of entropy production due to heat input at steam generator '
'(S_Q=' + str(round(sg.S_Q, 4)) + ') must equal the negative '
'value of entropy reduction in condenser (S_Q=' +
str(round(cd.S_Q, 4)) + ').')
assert round(sg.S_Q, 4) == -round(cd.S_Q, 4), msg
class TestClausiusRankine:
def setup(self):
"""Set up clausis rankine cycle with turbine driven feed water pump."""
self.Tamb = 20
self.pamb = 1
fluids = ['water']
self.nw = Network(fluids=fluids)
self.nw.set_attr(p_unit='bar', T_unit='C', h_unit='kJ / kg')
# create components
splitter1 = Splitter('splitter 1')
merge1 = Merge('merge 1')
turb = Turbine('turbine')
fwp_turb = Turbine('feed water pump turbine')
condenser = HeatExchangerSimple('condenser')
fwp = Pump('pump')
steam_generator = HeatExchangerSimple('steam generator')
cycle_close = CycleCloser('cycle closer')
# create busses
# power output bus
self.power = Bus('power_output')
self.power.add_comps({'comp': turb, 'char': 1})
# turbine driven feed water pump internal bus
self.fwp_power = Bus('feed water pump power', P=0)
self.fwp_power.add_comps({
'comp': fwp_turb,
'char': 1
}, {
'comp': fwp,
'char': 1,
'base': 'bus'
})
# heat input bus
self.heat = Bus('heat_input')
self.heat.add_comps({'comp': steam_generator, 'base': 'bus'})
self.nw.add_busses(self.power, self.fwp_power, self.heat)
# create connections
fs_in = Connection(cycle_close, 'out1', splitter1, 'in1', label='fs')
fs_fwpt = Connection(splitter1, 'out1', fwp_turb, 'in1')
fs_t = Connection(splitter1, 'out2', turb, 'in1')
fwpt_ws = Connection(fwp_turb, 'out1', merge1, 'in1')
t_ws = Connection(turb, 'out1', merge1, 'in2')
ws = Connection(merge1, 'out1', condenser, 'in1')
cond = Connection(condenser, 'out1', fwp, 'in1', label='cond')
fw = Connection(fwp, 'out1', steam_generator, 'in1', label='fw')
fs_out = Connection(steam_generator, 'out1', cycle_close, 'in1')
self.nw.add_conns(fs_in, fs_fwpt, fs_t, fwpt_ws, t_ws, ws, cond, fw,
fs_out)
# component parameters
turb.set_attr(eta_s=1)
fwp_turb.set_attr(eta_s=1)
condenser.set_attr(pr=1)
fwp.set_attr(eta_s=1)
steam_generator.set_attr(pr=1)
# connection parameters
fs_in.set_attr(m=10, p=120, T=600, fluid={'water': 1})
cond.set_attr(T=self.Tamb, x=0)
# solve network
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
def test_exergy_analysis_perfect_cycle(self):
"""Test exergy analysis in the perfect clausius rankine cycle."""
self.nw.exergy_analysis(self.pamb,
self.Tamb,
E_P=[self.power],
E_F=[self.heat],
internal_busses=[self.fwp_power])
msg = ('Exergy destruction of this network must be 0 (smaller than ' +
str(err**0.5) + ') for this test but is ' +
str(round(abs(self.nw.E_D), 4)) + ' .')
assert abs(self.nw.E_D) <= err**0.5, msg
msg = ('Exergy efficiency of this network must be 1 for this test but '
'is ' + str(round(self.nw.epsilon, 4)) + ' .')
assert round(self.nw.epsilon, 4) == 1, msg
exergy_balance = self.nw.E_F - self.nw.E_P - self.nw.E_L - self.nw.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(self.nw.E_F, 4)) +
'. Product exergy value: ' + str(round(self.nw.E_P, 4)) + '.')
assert round(abs(self.nw.E_F - self.nw.E_P), 4) < err**0.5, msg
def test_entropy_perfect_cycle(self):
"""Test entropy values in the perfect clausius rankine cycle."""
labels = [
'turbine', 'feed water pump turbine', 'condenser',
'steam generator', 'pump'
]
for label in labels:
cp = self.nw.get_comp(label)
msg = (
'Entropy production due to irreversibility must be 0 for all '
'components in this test but is ' + str(round(cp.S_irr, 4)) +
' at component ' + label + ' of type ' + cp.component() + '.')
assert round(cp.S_irr, 4) == 0, msg
sg = self.nw.get_comp('steam generator')
cd = self.nw.get_comp('condenser')
msg = (
'Value of entropy production due to heat input at steam generator '
'(S_Q=' + str(round(sg.S_Q, 4)) + ') must equal the negative '
'value of entropy reduction in condenser (S_Q=' +
str(round(cd.S_Q, 4)) + ').')
assert round(sg.S_Q, 4) == -round(cd.S_Q, 4), msg
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
self.nw.exergy_analysis(self.pamb,
self.Tamb,
E_P=[self.power],
E_F=[self.heat])
exergy_balance = self.nw.E_F - self.nw.E_P - self.nw.E_L - self.nw.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_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
self.nw.exergy_analysis(self.pamb,
self.Tamb,
E_P=[self.power],
E_F=[self.heat],
internal_busses=[self.fwp_power])
label = 'pump on bus feed water pump power'
eps = self.nw.component_exergy_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 on bus feed water pump power'
eps = self.nw.component_exergy_data.loc[label, 'epsilon']
eps = self.nw.component_exergy_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
def test_exergy_analysis_missing_E_F_E_P_information(self):
"""Test exergy analysis errors with missing information."""
with raises(TESPyNetworkError):
self.nw.exergy_analysis(self.pamb,
self.Tamb,
E_P=[self.power],
E_F=[])
with raises(TESPyNetworkError):
self.nw.exergy_analysis(self.pamb,
self.Tamb,
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):
self.nw.exergy_analysis(self.pamb,
self.Tamb,
E_P=[self.power],
E_F=[self.heat, self.power])
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.get_comp('compressor')
gt = self.nw.get_comp('turbine')
cc = self.nw.get_comp('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.get_conn('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)
