def test_initialization_isothermal():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(
default={
"property_package": m.fs.props,
"thermodynamic_assumption": ThermodynamicAssumption.isothermal
})
m.fs.pc.deltaP.fix(-1e3)
m.fs.pc.inlet.flow_mol.fix(27.5e3)
m.fs.pc.inlet.enth_mol.fix(4000)
m.fs.pc.inlet.pressure.fix(2e6)
assert degrees_of_freedom(m) == 0
init_state = {"flow_mol": 27.5e3, "pressure": 2e6, "enth_mol": 4000}
m.fs.pc.initialize(state_args=init_state, outlvl=5)
assert (pytest.approx(27500.0,
abs=1e-2) == m.fs.pc.outlet.flow_mol[0].value)
assert (pytest.approx(3999.984582673592,
abs=1e-2) == m.fs.pc.outlet.enth_mol[0].value)
assert (pytest.approx(1999000.0,
abs=1e-2) == m.fs.pc.outlet.pressure[0].value)
solver.solve(m)
def test_initialization_isentropic():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(
default={
"property_package": m.fs.props,
"thermodynamic_assumption": ThermodynamicAssumption.isentropic
})
init_state = {"flow_mol": 27.5e3, "pressure": 2e6, "enth_mol": 4000}
m.fs.pc.inlet.flow_mol.fix(27.5e3)
m.fs.pc.inlet.enth_mol.fix(4000)
m.fs.pc.inlet.pressure.fix(2e6)
m.fs.pc.deltaP.fix(-1e3)
m.fs.pc.efficiency_isentropic.fix(0.83)
assert degrees_of_freedom(m) == 0
m.fs.pc.initialize(state_args=init_state, outlvl=5, optarg={'tol': 1e-6})
assert (pytest.approx(27.5e3,
abs=1e-2) == m.fs.pc.outlet.flow_mol[0].value)
assert (pytest.approx(3999.979732728688,
abs=1e-2) == m.fs.pc.outlet.enth_mol[0].value)
assert (pytest.approx(1999000.0,
abs=1e-2) == m.fs.pc.outlet.pressure[0].value)
solver.solve(m)
def test_cv():
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(
default={"parameters": model.prop_param})
cond = read_data("prop.txt", col=7)
phase = read_data("prop.txt", col=13)
for i, c in enumerate(cond):
if c[2] == "undefined":
continue
if (c[0] > 640 and c[0] < 680) and (c[1] > 2.1e7 and c[1] < 3.1e7):
#near critical and non-analytic terms were omitted
continue
if phase[i][2] in ["liquid", "supercritical"]:
p = "Liq"
else:
p = "Vap"
model.prop_in.temperature.set_value(c[0])
model.prop_in.pressure = c[1]
cv = value(model.prop_in.cv_mol_phase[p] / model.prop_in.mw / 1000)
rho = value(model.prop_in.dens_mass_phase[p])
if rho > 250 and rho < 420 and c[0] < 700 and c[0] > 640:
tol = 0.03 # steep part in sc region
else:
tol = 0.003
assert (abs(cv - c[2]) / c[2] < tol)
def build_turbine():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.turb = TurbineOutletStage(
default={"property_package": m.fs.properties})
return m
def build_turbine_for_run_test():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
# roughly based on NETL baseline studies
m.fs.turb = TurbineMultistage(
default={
"property_package": m.fs.properties,
"num_hp": 7,
"num_ip": 14,
"num_lp": 11,
"hp_split_locations": [4, 7],
"ip_split_locations": [5, 14],
"lp_split_locations": [4, 7, 9, 11],
"hp_disconnect": [7],
"ip_split_num_outlets": {
14: 3
}
})
# Add reheater
m.fs.reheat = Heater(default={"property_package": m.fs.properties})
m.fs.hp_to_reheat = Arc(source=m.fs.turb.hp_split[7].outlet_1,
destination=m.fs.reheat.inlet)
m.fs.reheat_to_ip = Arc(source=m.fs.reheat.outlet,
destination=m.fs.turb.ip_stages[1].inlet)
return m
def test_fwh_model():
model = pyo.ConcreteModel()
model.fs = FlowsheetBlock(default={
"dynamic": False,
"default_property_package": iapws95.Iapws95ParameterBlock()})
model.fs.properties = model.fs.config.default_property_package
model.fs.fwh = FWH0D(default={
"has_desuperheat":True,
"has_drain_cooling":True,
"has_drain_mixer":True,
"property_package":model.fs.properties})
model.fs.fwh.desuperheat.inlet_1.flow_mol.fix(100)
model.fs.fwh.desuperheat.inlet_1.flow_mol.unfix()
model.fs.fwh.desuperheat.inlet_1.pressure.fix(201325)
model.fs.fwh.desuperheat.inlet_1.enth_mol.fix(60000)
model.fs.fwh.drain_mix.drain.flow_mol.fix(1)
model.fs.fwh.drain_mix.drain.pressure.fix(201325)
model.fs.fwh.drain_mix.drain.enth_mol.fix(20000)
model.fs.fwh.cooling.inlet_2.flow_mol.fix(400)
model.fs.fwh.cooling.inlet_2.pressure.fix(101325)
model.fs.fwh.cooling.inlet_2.enth_mol.fix(3000)
model.fs.fwh.condense.area.fix(1000)
model.fs.fwh.condense.overall_heat_transfer_coefficient.fix(100)
model.fs.fwh.desuperheat.area.fix(1000)
model.fs.fwh.desuperheat.overall_heat_transfer_coefficient.fix(10)
model.fs.fwh.cooling.area.fix(1000)
model.fs.fwh.cooling.overall_heat_transfer_coefficient.fix(10)
model.fs.fwh.initialize(optarg={"max_iter":50})
assert(degrees_of_freedom(model) == 0)
assert(abs(pyo.value(model.fs.fwh.desuperheat.inlet_1.flow_mol[0]) - 98.335) < 0.01)
def get_initialized_model(self):
"""
Returns an initialized model for the PressureChanger unit model
convergence evaluation
Returns
-------
Pyomo model : returns a pyomo model of the PressureChanger unit
"""
m = pe.ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(
default={
"property_package": m.fs.props,
"thermodynamic_assumption": 'isothermal'
})
m.fs.pc.deltaP.fix(-1e3)
m.fs.pc.inlet[:].flow_mol.fix(27.5e3)
m.fs.pc.inlet[:].enth_mol.fix(4000)
m.fs.pc.inlet[:].pressure.fix(2e6)
init_state = {"flow_mol": 27.5e3, "pressure": 2e6, "enth_mol": 4000}
m.fs.pc.initialize(state_args=init_state, outlvl=0)
# Create a solver for initialization
opt = self.get_solver()
opt.solve(m)
# return the initialized model
return m
def build_heat_exchanger():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.heat_exchanger = HeatExchanger(default={
"side_1":{"property_package": m.fs.properties},
"side_2":{"property_package": m.fs.properties}})
return m
def iapws(self):
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.unit = Heater(default={"property_package": m.fs.properties})
return m
def build_valve_liquid():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.valve = SteamValve(default={
"property_package": m.fs.properties,
"phase": "Liq"
})
return m
def test_tau_sat():
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(default={"parameters":model.prop_param})
cond = read_data("sat_prop.txt", col=2)
for c in cond:
tau = value(model.prop_in.func_tau_sat(c[1]/1000.0))
T = 647.096/tau
print("{}, {}, {}".format(c[1], c[0], T))
assert(abs(T-c[0]) < 0.1)
def test_build_pc():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(default={"property_package": m.fs.props})
assert hasattr(m.fs.pc, "inlet")
assert hasattr(m.fs.pc, "outlet")
assert len(m.fs.pc.inlet.vars) == 3
assert len(m.fs.pc.outlet.vars) == 3
def iapws(self):
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock(
default={"phase_presentation": iapws95.PhaseType.LG})
m.fs.unit = Feed(default={"property_package": m.fs.properties})
return m
def test_make_performance():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(default={"property_package": m.fs.props})
assert hasattr(m.fs.pc, "work_mechanical")
assert m.fs.pc.work_mechanical == m.fs.pc.control_volume.work
assert hasattr(m.fs.pc, "deltaP")
assert hasattr(m.fs.pc, "ratioP")
assert hasattr(m.fs.pc, "ratioP_calculation")
def test_set_geometry_include_holdup_true():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(default={
"property_package": m.fs.props,
"has_holdup": True
})
assert hasattr(m.fs.pc, "volume")
assert hasattr(m.fs.pc.control_volume, "material_holdup")
def test_make_isothermal():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(
default={
"property_package": m.fs.props,
"thermodynamic_assumption": ThermodynamicAssumption.isothermal
})
assert hasattr(m.fs.pc, "isothermal")
def test_report_isentropic():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(
default={
"property_package": m.fs.props,
"thermodynamic_assumption": ThermodynamicAssumption.isentropic
})
m.fs.pc.report()
def test_liquid_enthalpy_sat():
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(default={"parameters":model.prop_param})
cond = read_data("sat_prop.txt", col=5)
for c in cond:
if c[0] > 645: # getting very close to ciritical point
tol = 0.01
else:
tol = 0.001
model.prop_in.pressure = c[1]
enth = value(model.prop_in.enth_mol_sat_phase["Liq"]/model.prop_in.mw/1000.0)
assert(abs((enth-c[2])/c[2]) < tol)
def iapws(self):
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.unit = Mixer(
default={
"property_package": m.fs.properties,
"material_balance_type": MaterialBalanceType.componentTotal,
"momentum_mixing_type": MomentumMixingType.equality
})
return m
def iapws(self):
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.unit = PressureChanger(
default={
"property_package": m.fs.properties,
"thermodynamic_assumption": ThermodynamicAssumption.isentropic,
"compressor": True
})
return m
def test_vapor_density_sat():
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(default={"parameters":model.prop_param})
cond = read_data("sat_prop.txt", col=14)
for c in cond:
if c[0] > 645: # getting very close to ciritical point
tol = 0.01
else:
tol = 0.001
model.prop_in.temperature.set_value(c[0])
model.prop_in.pressure = c[1]
rho = value(model.prop_in.dens_mass_phase["Vap"])
assert(abs(rho-c[2])/c[2] < tol)
def iapws(self):
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock(
default={"phase_presentation": iapws95.PhaseType.LG})
m.fs.unit = Flash(
default={
"property_package": m.fs.properties,
"ideal_separation": False,
"energy_split_basis": EnergySplittingType.enthalpy_split
})
return m
def test_make_pump():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(
default={
"property_package": m.fs.props,
"thermodynamic_assumption": ThermodynamicAssumption.pump
})
assert hasattr(m.fs.pc, "work_fluid")
assert hasattr(m.fs.pc, "efficiency_pump")
assert hasattr(m.fs.pc, "fluid_work_calculation")
assert hasattr(m.fs.pc, "actual_work")
def test_enthalpy_vapor_as_function_of_p_and_tau():
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(default={"parameters":model.prop_param})
cond = read_data("prop.txt", col=5)
phase = read_data("prop.txt", col=13)
for i, c in enumerate(cond):
if phase[i][2] in ["liquid", "supercritical"]:
continue
model.prop_in.temperature.set_value(c[0])
h = value(model.prop_in.func_hvpt(c[1]/1000, 647.096/c[0]))
rho = value(model.prop_in.dens_mass_phase["Vap"])
if rho > 250 and rho < 420 and c[0] < 700 and c[0] > 640:
tol = 0.03 # steep part in sc region
else:
tol = 0.003
assert(abs(h-c[2])/c[2] < tol)
def iapws(self):
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.unit = HeatExchanger(
default={
"shell": {
"property_package": m.fs.properties
},
"tube": {
"property_package": m.fs.properties
},
"flow_pattern": HeatExchangerFlowPattern.countercurrent
})
return m
def test_make_isentropic():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.props = pp.Iapws95ParameterBlock()
m.fs.pc = PressureChanger(
default={
"property_package": m.fs.props,
"thermodynamic_assumption": ThermodynamicAssumption.isentropic
})
assert hasattr(m.fs.pc, "efficiency_isentropic")
assert hasattr(m.fs.pc, "work_isentropic")
assert hasattr(m.fs.pc, "isentropic_pressure")
assert hasattr(m.fs.pc, "isentropic_material")
assert hasattr(m.fs.pc, "isentropic")
assert hasattr(m.fs.pc, "isentropic_energy_balance")
assert hasattr(m.fs.pc, "actual_work")
def main():
"""
Make the flowsheet object, fix some variables, and solve the problem
"""
# Create a Concrete Model as the top level object
m = ConcreteModel()
# Add a flowsheet object to the model
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.prop_water = iapws95.Iapws95ParameterBlock()
build_boiler(m.fs)
TransformationFactory("network.expand_arcs").apply_to(m)
# Create a solver
solver = SolverFactory('ipopt')
return (m, solver)
def test_costing():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.unit = HeatExchanger(
default={
"shell": {
"property_package": m.fs.properties
},
"tube": {
"property_package": m.fs.properties
},
"flow_pattern": HeatExchangerFlowPattern.countercurrent
})
# Set inputs
m.fs.unit.inlet_1.flow_mol[0].fix(100)
m.fs.unit.inlet_1.enth_mol[0].fix(4000)
m.fs.unit.inlet_1.pressure[0].fix(101325)
m.fs.unit.inlet_2.flow_mol[0].fix(100)
m.fs.unit.inlet_2.enth_mol[0].fix(3500)
m.fs.unit.inlet_2.pressure[0].fix(101325)
m.fs.unit.area.fix(1000)
m.fs.unit.overall_heat_transfer_coefficient.fix(100)
assert degrees_of_freedom(m) == 0
m.fs.unit.initialize()
m.fs.unit.get_costing()
calculate_variable_from_constraint(m.fs.unit.costing.base_cost,
m.fs.unit.costing.base_cost_eq)
calculate_variable_from_constraint(m.fs.unit.costing.purchase_cost,
m.fs.unit.costing.cp_cost_eq)
results = solver.solve(m)
assert m.fs.unit.costing.purchase_cost.value == \
pytest.approx(52442.7363,1e-5)
def test_internal_energy():
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(default={"parameters":model.prop_param})
cond = read_data("prop.txt", col=4)
phase = read_data("prop.txt", col=13)
for i, c in enumerate(cond):
if phase[i][2] in ["liquid", "supercritical"]:
p = "Liq"
else:
p = "Vap"
model.prop_in.temperature.set_value(c[0])
model.prop_in.pressure = c[1]
u = value(model.prop_in.energy_internal_mol_phase[p]/model.prop_in.mw/1000)
rho = value(model.prop_in.dens_mass_phase[p])
if rho > 250 and rho < 420 and c[0] < 700 and c[0] > 640:
tol = 0.02 # steep part in sc region
else:
tol = 0.002
assert(abs(u-c[2])/c[2] < tol)
def test_density():
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(default={"parameters":model.prop_param})
cond = read_data("prop.txt", col=2)
phase = read_data("prop.txt", col=13)
for i, c in enumerate(cond):
if phase[i][2] in ["liquid", "supercritical"]:
p = "Liq"
else:
p = "Vap"
model.prop_in.temperature.set_value(c[0])
model.prop_in.pressure = c[1]
rho = value(model.prop_in.dens_mass_phase[p])
if rho > 250 and rho < 420 and c[0] < 700 and c[0] > 645:
tol = 0.03 # steep part in sc region
elif c[1] < 20:
tol = 0.005 #very low pressure < 20 Pa
else:
tol = 0.001
assert(abs(rho-c[2])/c[2] < tol)
