def test_vapor_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=17)
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["Vap"] /
model.prop_in.mw / 1000.0)
assert (abs((enth - c[2]) / c[2]) < tol)
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_liquid_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=2)
for c in cond:
if c[0] > 645: # getting very close to ciritical point
tol = 0.05
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["Liq"])
#print("{:.2f}, {:.2f}, {:.2f}, {:.2f}".format(c[0], c[1], rho, c[2]))
assert (abs(rho - c[2]) / c[2] < tol)
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 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 test_entropy():
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(
default={"parameters": model.prop_param})
cond = read_data("prop.txt", col=6)
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]
s = value(model.prop_in.entr_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(s - 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)
def test_enthalpy_of_vaporization():
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(
default={"parameters": model.prop_param})
cond_liq = read_data("sat_prop.txt", col=5)
cond_vap = read_data("sat_prop.txt", col=17)
for i, c in enumerate(cond_liq):
if c[0] > 645: # getting very close to ciritical point
tol = 0.05
else:
tol = 0.001
model.prop_in.pressure.value = c[1]
enth = value(model.prop_in.dh_vap_mol / model.prop_in.mw / 1000.0)
enth_dat = cond_vap[i][2] - c[2]
if abs(enth_dat) > 1e-8:
assert (abs((enth - enth_dat) / enth_dat) < tol)
else:
assert (abs(enth - enth_dat) < tol)
#Over Critical Pressure
model.prop_in.pressure = model.prop_in.config.parameters.pressure_crit * 1.1
enth = value(model.prop_in.dh_vap_mol / model.prop_in.mw / 1000.0)
assert (abs(enth) < 0.001)
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_heater():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95_ph.Iapws95ParameterBlock()
m.fs.heater = Heater(default={"property_package": m.fs.properties})
return m
def build_turbine():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95_ph.Iapws95ParameterBlock()
m.fs.turb = TurbineStage(default={"property_package": m.fs.properties})
return m
def make_model(self):
model = ConcreteModel()
model.prop_param = iapws95.Iapws95ParameterBlock()
model.prop_in = iapws95.Iapws95StateBlock(default={"parameters":model.prop_param})
return model
def build_valve_vapor():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95_ph.Iapws95ParameterBlock()
m.fs.valve = SteamValve(default={"property_package": m.fs.properties})
return m
