def run_simple_heat_pump_model():
nw = Network(['NH3'], T_unit='C', p_unit='bar', h_unit='kJ / kg')
nw.set_attr(iterinfo=False)
cp = Compressor('compressor')
cc = CycleCloser('cycle_closer')
cd = HeatExchangerSimple('condenser')
va = Valve('expansion valve')
ev = HeatExchangerSimple('evaporator')
cc_cd = Connection(cc, 'out1', cd, 'in1')
cd_va = Connection(cd, 'out1', va, 'in1')
va_ev = Connection(va, 'out1', ev, 'in1')
ev_cp = Connection(ev, 'out1', cp, 'in1')
cp_cc = Connection(cp, 'out1', cc, 'in1')
nw.add_conns(cc_cd, cd_va, va_ev, ev_cp, cp_cc)
cd.set_attr(pr=0.95, Q=-1e6)
ev.set_attr(pr=0.9)
cp.set_attr(eta_s=0.9)
cc_cd.set_attr(fluid={'NH3': 1})
cd_va.set_attr(Td_bp=-5, T=85)
ev_cp.set_attr(Td_bp=5, T=15)
nw.solve('design')
result_dict = {}
result_dict.update({
cp.label: cp.get_plotting_data()[1]
for cp in nw.comps.index if cp.get_plotting_data() is not None
})
return result_dict
class TestCompressedAirIn:
def setup(self):
"""Set up air compressor."""
self.Tamb = 20
self.pamb = 1
fluids = ['Air']
# compressor part
self.nw = Network(fluids=fluids)
self.nw.set_attr(p_unit='bar', T_unit='C', h_unit='kJ / kg')
# components
amb = Source('air intake')
cp = Compressor('compressor')
cooler = HeatExchangerSimple('cooling')
cas = Sink('compressed air storage')
# power input bus
self.power_in = Bus('power input')
self.power_in.add_comps({'comp': cp, 'char': 1, 'base': 'bus'})
# compressed air bus (not sure about this!)
self.cas_in = Bus('massflow into storage')
self.cas_in.add_comps({'comp': cas}, {'comp': amb, 'base': 'bus'})
self.nw.add_busses(self.power_in, self.cas_in)
# create connections
amb_cp = Connection(amb, 'out1', cp, 'in1')
cp_cool = Connection(cp, 'out1', cooler, 'in1')
cool_cas = Connection(cooler, 'out1', cas, 'in1')
self.nw.add_conns(amb_cp, cp_cool, cool_cas)
# component parameters
cp.set_attr(eta_s=1)
cooler.set_attr(pr=1)
# connection parameters
amb_cp.set_attr(m=2, T=self.Tamb, p=self.pamb, fluid={'Air': 1})
cool_cas.set_attr(T=self.Tamb, p=10)
# solve network
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
def test_exergy_analysis_bus_conversion(self):
"""Test exergy analysis at product exergy with T < Tamb."""
self.nw.exergy_analysis(self.pamb,
self.Tamb,
E_P=[self.cas_in],
E_F=[self.power_in])
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
class TestSEGS:
def setup(self):
"""
Full model validation of SEGS model in TESPy vs. EBSILON.
Find original models at https://github.com/fwitte/SEGS_exergy.
"""
# specification of ambient state
self.pamb = 1.013
self.Tamb = 25
# setting up network
self.nw = Network(fluids=['water', 'INCOMP::TVP1', 'air'])
self.nw.set_attr(T_unit='C',
p_unit='bar',
h_unit='kJ / kg',
m_unit='kg / s',
s_unit="kJ / kgK")
# components definition
air_in = Source('Ambient air source', fkt_group='CW')
air_out = Sink('Ambient air sink', fkt_group='CW')
closer_pt = CycleCloser('Cycle closer pt', fkt_group='SF')
pt = ParabolicTrough('Parabolic trough', fkt_group='SF')
ptpump = Pump('HTF pump', fkt_group='SF')
closer = CycleCloser('Cycle closer power cycle', fkt_group='SG')
eco = HeatExchanger('Economizer', fkt_group='SG')
eva = HeatExchanger('Evaporator', fkt_group='SG')
sup = HeatExchanger('Superheater', fkt_group='SG')
drum = Drum('Drum', fkt_group='SG')
reh = HeatExchanger('Reheater', fkt_group='RH')
hpt1 = Turbine('HP turbine 1', fkt_group='HPT')
hpt2 = Turbine('HP turbine 2', fkt_group='HPT')
lpt1 = Turbine('LP turbine 1', fkt_group='LPT')
lpt2 = Turbine('LP turbine 2', fkt_group='LPT')
lpt3 = Turbine('LP turbine 3', fkt_group='LPT')
lpt4 = Turbine('LP turbine 4', fkt_group='LPT')
lpt5 = Turbine('LP turbine 5', fkt_group='LPT')
cond = Condenser('Condenser', fkt_group='CW')
condpump = Pump('Condenser pump', fkt_group='CW')
fwt = Merge('Feedwater tank', num_in=3, fkt_group='LPP')
fwp = Pump('Feedwater pump', fkt_group='FWP')
cwp = Pump('Cooling water pump', fkt_group='CW')
closer_cw = CycleCloser('Cycle closer cw', fkt_group='CW')
ct = HeatExchanger('Cooling tower', fkt_group='CW')
fan = Compressor('Cooling tower fan', fkt_group='CW')
sp1 = Splitter('Splitter 1', fkt_group='HPT')
sp2 = Splitter('Splitter 2', fkt_group='HPT')
sp3 = Splitter('Splitter 3', fkt_group='LPT')
sp4 = Splitter('Splitter 4', fkt_group='LPT')
sp5 = Splitter('Splitter 5', fkt_group='LPT')
sp6 = Splitter('Splitter 6', fkt_group='LPT')
sp7 = Splitter('Splitter 7', fkt_group='SF')
m1 = Merge('Merge 1', fkt_group='CW')
m2 = Merge('Merge 2', fkt_group='HPP')
m3 = Merge('Merge 3', fkt_group='LPP')
m4 = Merge('Merge 4', fkt_group='LPP')
m5 = Merge('Merge 5', fkt_group='SF')
v1 = Valve('Valve 1', fkt_group='HPP')
v2 = Valve('Valve 2', fkt_group='HPP')
v3 = Valve('Valve 3', fkt_group='LPP')
v4 = Valve('Valve 4', fkt_group='LPP')
v5 = Valve('Valve 5', fkt_group='LPP')
hppre1 = Condenser('High pressure preheater 1', fkt_group='HPP')
hppre2 = Condenser('High pressure preheater 2', fkt_group='HPP')
hppre1_sub = HeatExchanger('High pressure preheater 1 subcooling',
fkt_group='HPP')
hppre2_sub = HeatExchanger('High pressure preheater 2 subcooling',
fkt_group='HPP')
lppre1 = Condenser('Low pressure preheater 1', fkt_group='LPP')
lppre2 = Condenser('Low pressure preheater 2', fkt_group='LPP')
lppre3 = Condenser('Low pressure preheater 3', fkt_group='LPP')
lppre1_sub = HeatExchanger('Low pressure preheater 1 subcooling',
fkt_group='LPP')
lppre2_sub = HeatExchanger('Low pressure preheater 2 subcooling',
fkt_group='LPP')
lppre3_sub = HeatExchanger('Low pressure preheater 3 subcooling',
fkt_group='LPP')
# connections definition
# power cycle
c1 = Connection(sup, 'out2', closer, 'in1', label='1')
c2 = Connection(closer, 'out1', hpt1, 'in1', label='2')
c3 = Connection(hpt1, 'out1', sp1, 'in1', label='3')
c4 = Connection(sp1, 'out1', hpt2, 'in1', label='4')
c5 = Connection(hpt2, 'out1', sp2, 'in1', label='5')
c6 = Connection(sp2, 'out1', reh, 'in2', label='6')
c7 = Connection(reh, 'out2', lpt1, 'in1', label='7')
c8 = Connection(lpt1, 'out1', sp3, 'in1', label='8')
c9 = Connection(sp3, 'out1', lpt2, 'in1', label='9')
c10 = Connection(lpt2, 'out1', sp4, 'in1', label='10')
c11 = Connection(sp4, 'out1', lpt3, 'in1', label='11')
c12 = Connection(lpt3, 'out1', sp5, 'in1', label='12')
c13 = Connection(sp5, 'out1', lpt4, 'in1', label='13')
c14 = Connection(lpt4, 'out1', sp6, 'in1', label='14')
c15 = Connection(sp6, 'out1', lpt5, 'in1', label='15')
c16 = Connection(lpt5, 'out1', m1, 'in1', label='16')
c17 = Connection(m1, 'out1', cond, 'in1', label='17')
c18 = Connection(cond, 'out1', condpump, 'in1', label='18')
c19 = Connection(condpump, 'out1', lppre1, 'in2', label='19')
# c19 = Connection(condpump, 'out1', lppre1_sub, 'in2', label='19')
# c20 = Connection(lppre1_sub, 'out2', lppre1, 'in2', label='20')
c21 = Connection(lppre1, 'out2', lppre2, 'in2', label='21')
# c21 = Connection(lppre1, 'out2', lppre2_sub, 'in2', label='21')
# c22 = Connection(lppre2_sub, 'out2', lppre2, 'in2', label='22')
c23 = Connection(lppre2, 'out2', lppre3, 'in2', label='23')
# c23 = Connection(lppre2, 'out2', lppre3_sub, 'in2', label='23')
# c24 = Connection(lppre3_sub, 'out2', lppre3, 'in2', label='24')
c25 = Connection(lppre3, 'out2', fwt, 'in1', label='25')
c26 = Connection(fwt, 'out1', fwp, 'in1', label='26')
c27 = Connection(fwp, 'out1', hppre1, 'in2', label='27')
c29 = Connection(hppre1, 'out2', hppre2, 'in2', label='29')
c31 = Connection(hppre2, 'out2', eco, 'in2', label='31')
c36 = Connection(sp1, 'out2', hppre2, 'in1', label='36')
c37 = Connection(hppre2, 'out1', v1, 'in1', label='37')
c39 = Connection(v1, 'out1', m2, 'in2', label='39')
c40 = Connection(sp2, 'out2', m2, 'in1', label='40')
c41 = Connection(m2, 'out1', hppre1, 'in1', label='41')
c42 = Connection(hppre1, 'out1', v2, 'in1', label='42')
c44 = Connection(v2, 'out1', fwt, 'in2', label='44')
c45 = Connection(sp3, 'out2', fwt, 'in3', label='45')
c46 = Connection(sp4, 'out2', lppre3, 'in1', label='46')
c47 = Connection(lppre3, 'out1', v3, 'in1', label='47')
# c47 = Connection(lppre3, 'out1', lppre3_sub, 'in1', label='47')
# c48 = Connection(lppre3_sub, 'out1', v3, 'in1', label='48')
c49 = Connection(v3, 'out1', m3, 'in1', label='49')
c50 = Connection(sp5, 'out2', m3, 'in2', label='50')
c51 = Connection(m3, 'out1', lppre2, 'in1', label='51')
c52 = Connection(lppre2, 'out1', v4, 'in1', label='52')
# c52 = Connection(lppre2, 'out1', lppre2_sub, 'in1', label='52')
# c53 = Connection(lppre2_sub, 'out1', v4, 'in1', label='53')
c54 = Connection(v4, 'out1', m4, 'in2', label='54')
c55 = Connection(sp6, 'out2', m4, 'in1', label='55')
c56 = Connection(m4, 'out1', lppre1, 'in1', label='56')
c57 = Connection(lppre1, 'out1', v5, 'in1', label='57')
# c57 = Connection(lppre1, 'out1', lppre1_sub, 'in1', label='57')
# c58 = Connection(lppre1_sub, 'out1', v5, 'in1', label='58')
c59 = Connection(v5, 'out1', m1, 'in2', label='59')
# components from subsystem
c32 = Connection(eco, 'out2', drum, 'in1', label='32')
c33 = Connection(drum, 'out1', eva, 'in2', label='33')
c34 = Connection(eva, 'out2', drum, 'in2', label='34')
c35 = Connection(drum, 'out2', sup, 'in2', label='35')
c73 = Connection(sup, 'out1', eva, 'in1', label='73')
c74 = Connection(eva, 'out1', eco, 'in1', label='74')
# cooling water
c60 = Connection(cond, 'out2', closer_cw, 'in1', label='60')
c61 = Connection(closer_cw, 'out1', ct, 'in1', label='61')
c62 = Connection(ct, 'out1', cwp, 'in1', label='62')
c63 = Connection(cwp, 'out1', cond, 'in2', label='63')
# cooling tower
c64 = Connection(air_in, 'out1', fan, 'in1', label='64')
c65 = Connection(fan, 'out1', ct, 'in2', label='65')
c66 = Connection(ct, 'out2', air_out, 'in1', label='66')
# parabolic trough cycle
c70 = Connection(pt, 'out1', closer_pt, 'in1', label='67')
c71 = Connection(closer_pt, 'out1', sp7, 'in1', label='71')
c72 = Connection(sp7, 'out1', sup, 'in1', label='72')
c75 = Connection(eco, 'out1', m5, 'in1', label='75')
c76 = Connection(sp7, 'out2', reh, 'in1', label='76')
c77 = Connection(reh, 'out1', m5, 'in2', label='77')
c78 = Connection(m5, 'out1', ptpump, 'in1', label='78')
c79 = Connection(ptpump, 'out1', pt, 'in1', label='79')
# add connections to network
self.nw.add_conns(c1, c2, c3, c4, c5, c6, c7, c8, c9, c10, c11, c12,
c13, c14, c15, c16, c17, c18, c19, c21, c23, c25,
c26, c27, c29, c31, c32, c33, c34, c35, c36, c37,
c39, c40, c41, c42, c44, c45, c46, c47, c49, c50,
c51, c52, c54, c55, c56, c57, c59, c60, c61, c62,
c63, c64, c65, c66, c70, c71, c72, c73, c74, c75,
c76, c77, c78, c79)
# power bus
power = Bus('total output power')
power.add_comps({
'comp': hpt1,
'char': 0.97,
'base': 'component'
}, {
'comp': hpt2,
'char': 0.97,
'base': 'component'
}, {
'comp': lpt1,
'char': 0.97,
'base': 'component'
}, {
'comp': lpt2,
'char': 0.97,
'base': 'component'
}, {
'comp': lpt3,
'char': 0.97,
'base': 'component'
}, {
'comp': lpt4,
'char': 0.97,
'base': 'component'
}, {
'comp': lpt5,
'char': 0.97,
'base': 'component'
}, {
'comp': fwp,
'char': 0.95,
'base': 'bus'
}, {
'comp': condpump,
'char': 0.95,
'base': 'bus'
}, {
'comp': ptpump,
'char': 0.95,
'base': 'bus'
}, {
'comp': cwp,
'char': 0.95,
'base': 'bus'
}, {
'comp': fan,
'char': 0.95,
'base': 'bus'
})
heat_input_bus = Bus('heat input')
heat_input_bus.add_comps({'comp': pt, 'base': 'bus'})
exergy_loss_bus = Bus('exergy loss')
exergy_loss_bus.add_comps({
'comp': air_in,
'base': 'bus'
}, {'comp': air_out})
self.nw.add_busses(power, heat_input_bus, exergy_loss_bus)
# component parameters
pt.set_attr(doc=0.95,
aoi=0,
Tamb=25,
A='var',
eta_opt=0.73,
c_1=0.00496,
c_2=0.000691,
E=1000,
iam_1=1,
iam_2=1)
ptpump.set_attr(eta_s=0.6)
eco.set_attr()
eva.set_attr(ttd_l=5)
sup.set_attr()
hpt1.set_attr(eta_s=0.8376)
hpt2.set_attr(eta_s=0.8463)
lpt1.set_attr(eta_s=0.8623)
lpt2.set_attr(eta_s=0.917)
lpt3.set_attr(eta_s=0.9352)
lpt4.set_attr(eta_s=0.88)
lpt5.set_attr(eta_s=0.6445)
cond.set_attr(pr1=1, pr2=0.9, ttd_u=5)
condpump.set_attr(eta_s=0.7)
fwp.set_attr(eta_s=0.7)
cwp.set_attr(eta_s=0.7)
ct.set_attr(pr1=0.95)
fan.set_attr(eta_s=0.6)
lppre1.set_attr(pr1=1, ttd_u=5)
lppre2.set_attr(pr1=1, ttd_u=5)
lppre3.set_attr(pr1=1, ttd_u=5)
hppre1.set_attr(pr1=1, ttd_u=5)
hppre2.set_attr(pr1=1, ttd_u=5)
lppre1_sub.set_attr(pr1=1, pr2=1, ttd_l=10)
lppre2_sub.set_attr(pr1=1, pr2=1, ttd_l=10)
lppre3_sub.set_attr(pr1=1, pr2=1, ttd_l=10)
hppre1_sub.set_attr(pr1=1, pr2=1, ttd_l=10)
hppre2_sub.set_attr(pr1=1, pr2=1, ttd_l=10)
# connection parameters
# parabolic trough cycle
c70.set_attr(fluid={'TVP1': 1, 'water': 0, 'air': 0}, T=390, p=23.304)
c76.set_attr(m=Ref(c70, 0.1284, 0))
c73.set_attr(p=22.753)
c74.set_attr(p=21.167)
c78.set_attr(p=20.34)
c79.set_attr(p=41.024)
# cooling water
c62.set_attr(fluid={
'TVP1': 0,
'water': 1,
'air': 0
},
T=30,
p=self.pamb)
# cooling tower
c64.set_attr(fluid={
'water': 0,
'TVP1': 0,
'air': 1
},
p=self.pamb,
T=self.Tamb)
c65.set_attr(p=self.pamb + 0.0005)
c66.set_attr(p=self.pamb, T=30)
# power cycle
c32.set_attr(Td_bp=-2)
c34.set_attr(x=0.5)
c1.set_attr(fluid={'water': 1, 'TVP1': 0, 'air': 0}, p=100, T=371)
# steam generator pressure values
c31.set_attr(p=103.56)
c35.set_attr(p=103.42)
# turbine pressure values
c3.set_attr(p=33.61, m=38.969)
c5.set_attr(p=18.58)
c7.set_attr(p=17.1, T=371)
c8.set_attr(p=7.98)
c10.set_attr(p=2.73)
c12.set_attr(p=0.96)
c14.set_attr(p=0.29)
# preheater pressure values
c19.set_attr(p=14.755, state='l')
c21.set_attr(p=9.9975, state='l')
c23.set_attr(p=8.7012, state='l')
c25.set_attr(state='l')
c27.set_attr(p=125)
c29.set_attr(p=112)
# condensation
c16.set_attr(p=0.08)
# feedwater tank
c26.set_attr(x=0)
# a stable solution is generated for parts of the network
self.nw.solve(mode='design')
self.nw.del_conns(c19, c21, c23, c27, c29, c37, c42, c47, c52, c57)
c19 = Connection(condpump, 'out1', lppre1_sub, 'in2', label='19')
c20 = Connection(lppre1_sub, 'out2', lppre1, 'in2', label='20')
c21 = Connection(lppre1, 'out2', lppre2_sub, 'in2', label='21')
c22 = Connection(lppre2_sub, 'out2', lppre2, 'in2', label='22')
c23 = Connection(lppre2, 'out2', lppre3_sub, 'in2', label='23')
c24 = Connection(lppre3_sub, 'out2', lppre3, 'in2', label='24')
c27 = Connection(fwp, 'out1', hppre1_sub, 'in2', label='27')
c28 = Connection(hppre1_sub, 'out2', hppre1, 'in2', label='28')
c29 = Connection(hppre1, 'out2', hppre2_sub, 'in2', label='29')
c30 = Connection(hppre2_sub, 'out2', hppre2, 'in2', label='30')
c37 = Connection(hppre2, 'out1', hppre2_sub, 'in1', label='37')
c38 = Connection(hppre2_sub, 'out1', v1, 'in1', label='38')
c42 = Connection(hppre1, 'out1', hppre1_sub, 'in1', label='42')
c43 = Connection(hppre1_sub, 'out1', v2, 'in1', label='43')
c47 = Connection(lppre3, 'out1', lppre3_sub, 'in1', label='47')
c48 = Connection(lppre3_sub, 'out1', v3, 'in1', label='48')
c52 = Connection(lppre2, 'out1', lppre2_sub, 'in1', label='52')
c53 = Connection(lppre2_sub, 'out1', v4, 'in1', label='53')
c57 = Connection(lppre1, 'out1', lppre1_sub, 'in1', label='57')
c58 = Connection(lppre1_sub, 'out1', v5, 'in1', label='58')
self.nw.add_conns(c19, c20, c21, c22, c23, c24, c27, c28, c29, c30,
c37, c38, c42, c43, c47, c48, c52, c53, c57, c58)
# specification of missing parameters
c19.set_attr(p=14.755)
c21.set_attr(p=9.9975, state='l')
c23.set_attr(p=8.7012, state='l')
c27.set_attr(p=125)
c29.set_attr(p=112)
# solve final state
self.nw.solve(mode='design')
def test_model(self):
"""Test the thermodynamic model."""
power_ebsilon = -31.769
power_tespy = round(self.nw.busses['total output power'].P.val / 1e6,
3)
msg = ('The total power calculated (' + str(power_tespy) +
') does not '
'match the power calculated with the EBSILON model (' +
str(power_ebsilon) + ').')
assert power_tespy == power_ebsilon, msg
T_c79_ebsilon = 296.254
T_c79_tespy = round(self.nw.get_conn('79').T.val, 3)
msg = ('The temperature at connection 79 calculated (' +
str(T_c79_tespy) +
') does not match the temperature calculated '
'with the EBSILON model (' + str(T_c79_ebsilon) + ').')
assert T_c79_tespy == T_c79_ebsilon, 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
E_P.append(E_F)
comps.append("E_P")
E_D.append(0)
E_P.append(E_F)
# create data frame and save data
df_comps = pd.DataFrame(columns=comps)
df_comps.loc["E_D"] = E_D
df_comps.loc["E_P"] = E_P
df_comps.to_csv('R410A_E_D.csv')
# %% further calculations
print("\n#### FURTHER CALCULATIONS ####\n")
# switch off iterinfo
nw.set_attr(iterinfo=False)
# offdesign test
nw.solve('offdesign', design_path=path)
# %% calculate epsilon depending on:
# - ambient temperature Tamb
# - mean geothermal temperature Tgeo
Tamb_design = Tamb
Tgeo_design = Tgeo
i = 0
# create data ranges and frames
Tamb_range = [1, 4, 8, 12, 16, 20]
Tgeo_range = [11.5, 10.5, 9.5, 8.5, 7.5, 6.5]
df_eps_Tamb = pd.DataFrame(columns=Tamb_range)
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 TestCompressedAirOut:
def setup(self):
"""Set up air compressed air turbine."""
self.Tamb = 20
self.pamb = 1
fluids = ['Air']
# turbine part
self.nw = Network(fluids=fluids)
self.nw.set_attr(p_unit='bar', T_unit='C', h_unit='kJ / kg')
# components
cas = Source('compressed air storage')
reheater = HeatExchangerSimple('reheating')
turb = Turbine('turbine')
amb = Sink('air outlet')
# power ouput bus
self.power_out = Bus('power output')
self.power_out.add_comps({'comp': turb, 'char': 1})
# compressed air bus
self.cas_out = Bus('exergy in')
self.cas_out.add_comps({
'comp': cas,
'base': 'bus'
}, {
'comp': reheater,
'base': 'bus'
})
# exergy loss bus
self.ex_loss = Bus('exergy loss')
self.ex_loss.add_comps({'comp': amb, 'base': 'component'})
self.nw.add_busses(self.power_out, self.cas_out)
# create connections
cas_reheater = Connection(cas, 'out1', reheater, 'in1')
reheater_turb = Connection(reheater, 'out1', turb, 'in1')
turb_amb = Connection(turb, 'out1', amb, 'in1', label='outlet')
self.nw.add_conns(cas_reheater, reheater_turb, turb_amb)
# component parameters
turb.set_attr(eta_s=1)
reheater.set_attr(pr=1)
# connection parameters
cas_reheater.set_attr(m=2, T=self.Tamb, p=10, fluid={'Air': 1})
reheater_turb.set_attr()
turb_amb.set_attr(p=self.pamb, T=self.Tamb)
# solve network
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
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
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 TestRefrigerator:
def setup(self):
"""Set up simple refrigerator."""
self.Tamb = 20
self.pamb = 1
fluids = ['R134a']
self.nw = Network(fluids=fluids)
self.nw.set_attr(p_unit='bar', T_unit='C', h_unit='kJ / kg')
# create components
va = Valve('expansion valve')
cp = Compressor('compressor')
cond = HeatExchangerSimple('condenser')
eva = HeatExchangerSimple('evaporator')
cc = CycleCloser('cycle closer')
# create busses
# power output bus
self.power = Bus('power input')
self.power.add_comps({'comp': cp, 'char': 1, 'base': 'bus'})
# cooling bus
self.cool = Bus('heat from fridge')
self.cool.add_comps({'comp': eva})
# heat input bus
self.heat = Bus('heat to ambient')
self.heat.add_comps({'comp': cond})
self.nw.add_busses(self.power, self.cool, self.heat)
# create connections
cc_cp = Connection(cc, 'out1', cp, 'in1', label='from eva')
cp_cond = Connection(cp, 'out1', cond, 'in1', label='to cond')
cond_va = Connection(cond, 'out1', va, 'in1', label='from cond')
va_eva = Connection(va, 'out1', eva, 'in1', label='to eva')
eva_cc = Connection(eva, 'out1', cc, 'in1')
self.nw.add_conns(cc_cp, cp_cond, cond_va, va_eva, eva_cc)
# component parameters
cp.set_attr(eta_s=0.9)
cond.set_attr(pr=0.97)
eva.set_attr(pr=0.96)
# connection parameters
cc_cp.set_attr(m=1, x=1, T=-25, fluid={'R134a': 1})
cond_va.set_attr(x=0, T=self.Tamb + 1)
# solve network
self.nw.solve('design')
convergence_check(self.nw.lin_dep)
def test_exergy_analysis_bus_conversion(self):
"""Test exergy analysis at product exergy with T < Tamb."""
# no exergy losses in this case
ean = ExergyAnalysis(self.nw, E_P=[self.cool], E_F=[self.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
from tespy.networks import Network
from tespy.components import (Sink, Source, Turbine, Condenser,
Pump, HeatExchangerSimple, CycleCloser)
from tespy.connections import Connection, Bus, Ref
from tespy.tools.characteristics import CharLine
from tespy.tools import document_model
import numpy as np
# %% network
fluids = ['water']
nw = Network(fluids=fluids)
nw.set_attr(
p_unit='bar', T_unit='C', h_unit='kJ / kg',
p_range=[0.01, 150], h_range=[10, 5000])
# %% 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')
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 TestExpansion:
def setup(self):
self.Tamb = 20
self.pamb = 1
fluids = ['Air']
# turbine part
self.nw = Network(fluids=fluids)
self.nw.set_attr(p_unit='bar', T_unit='C', h_unit='kJ / kg')
# components
so = Source('inlet')
tu = Turbine('compressor')
si = Sink('outlet')
# fuel exergy bus
self.exergy_fuel = Bus('fuel exergy')
self.exergy_fuel.add_comps({'comp': si}, {'comp': so, 'base': 'bus'})
# product exergy bus
self.exergy_prod = Bus('product exergy')
self.exergy_prod.add_comps({'comp': tu, 'char': 0.9})
# create connections
c1 = Connection(so, 'out1', tu, 'in1', '1')
c2 = Connection(tu, 'out1', si, 'in1', '2')
self.nw.add_conns(c1, c2)
# component parameters
tu.set_attr(eta_s=0.85, pr=1 / 5)
# connection parameters
c1.set_attr(m=2, p=10, fluid={'Air': 1})
c2.set_attr(T=self.Tamb)
# solve network
self.nw.solve('design')
def test_larger_T0(self):
self.nw.get_conn('2').set_attr(T=self.Tamb + 10)
self.nw.solve('design')
self.run_analysis()
def test_T0_cross(self):
self.nw.get_conn('2').set_attr(T=self.Tamb - 30)
self.nw.solve('design')
self.run_analysis()
def test_smaller_T0(self):
self.nw.get_conn('1').set_attr(T=self.Tamb - 10)
self.nw.get_conn('2').set_attr(T=None)
self.nw.solve('design')
self.run_analysis()
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
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])
