Turbine (Stage)#

This is a steam power generation turbine model for intermediate stages between the inlet and outlet. It inherits HelmIsentropicTurbine <reference_guides/model_libraries/power_generation/unit_models/turbine_inlet:Turbine (Isentropic)>.

Example#

from pyomo.environ import ConcreteModel, SolverFactory

from idaes.core import FlowsheetBlock
from idaes.models_extra.power_generation.unit_models.helm import HelmTurbineStage
from idaes.models.properties import iapws95

m = ConcreteModel()
m.fs = FlowsheetBlock(dynamic=False)
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.turb = HelmTurbineStage(property_package=m.fs.properties)
# set inlet
m.fs.turb.inlet[:].enth_mol.fix(70000)
m.fs.turb.inlet[:].flow_mol.fix(15000)
m.fs.turb.inlet[:].pressure.fix(8e6)
m.fs.turb.efficiency_isentropic[:].fix(0.8)
m.fs.turb.ratioP[:].fix(0.7)
m.fs.turb.initialize()

Variables#

Variable

Symbol

Index Sets

Doc

efficiency_mech

\(\eta_{mech}\)

None

Mechanical efficiency (accounts for losses in bearings…)

efficiency_isentropic

\(\eta_{isen}\)

time

Isentropic efficiency

deltaP

\(\Delta P\)

time

Pressure change (\(P_{out} - P_{in}\)) [Pa]

ratioP

\(P_{ratio}\)

time

Ratio of discharge pressure to inlet pressure \(\left(\frac{P_{out}}{P_{in}}\right)\)

shaft_speed

\(s\)

time

Shaft speed [hz]

The shaft speed is used to calculate specific speed for more advanced turbine models, the specific speed expression is available, but otherwise has no effect on the model results.

Expressions#

This model provides two expressions that are not available in the pressure changer model.

Variable

Symbol

Index Sets

Doc

power_thermo

\(\dot{w}_{thermo}\)

time

Turbine stage power output not including mechanical loss [W]

power_shaft

\(\dot{w}_{shaft}\)

time

Turbine stage power output including mechanical loss (bearings…) [W]

specific_speed

\(n_s\)

time

Turbine stage specific speed [dimensionless]

\[n_s = s\dot{v}^0.5 (w_{isen} / \dot{m}) ** (-0.75)\]

Where \(\dot{m}\) is the mass flow rate and \(\dot{v}\) is the outlet volumetric flow.

Constraints#

There are no additional constraints.

Initialization#

To initialize the turbine model, a reasonable guess for the inlet condition and deltaP and efficiency should be set by setting the appropriate variables.

TurbineStage Class#

class idaes.models_extra.power_generation.unit_models.helm.turbine_stage.HelmTurbineStage(*args, **kwds)#

Basic steam turbine model

Parameters:
  • rule (function) – A rule function or None. Default rule calls build().

  • concrete (bool) – If True, make this a toplevel model. Default - False.

  • ctype (class) –

    Pyomo ctype of the block. Default - pyomo.environ.Block

    Config args

    dynamic

    Indicates whether this model will be dynamic or not, default = useDefault. Valid values: { useDefault - get flag from parent (default = False), True - set as a dynamic model, False - set as a steady-state model.}

    has_holdup

    Indicates whether holdup terms should be constructed or not. Must be True if dynamic = True, default - False. Valid values: { useDefault - get flag from parent (default = False), True - construct holdup terms, False - do not construct holdup terms}

    material_balance_type

    Indicates what type of mass balance should be constructed, default - MaterialBalanceType.useDefault. Valid values: { MaterialBalanceType.useDefault - refer to property package for default balance type **MaterialBalanceType.none - exclude material balances, MaterialBalanceType.componentPhase - use phase component balances, MaterialBalanceType.componentTotal - use total component balances, MaterialBalanceType.elementTotal - use total element balances, MaterialBalanceType.total - use total material balance.}

    energy_balance_type

    Indicates what type of energy balance should be constructed, default - EnergyBalanceType.useDefault. Valid values: { EnergyBalanceType.useDefault - refer to property package for default balance type **EnergyBalanceType.none - exclude energy balances, EnergyBalanceType.enthalpyTotal - single enthalpy balance for material, EnergyBalanceType.enthalpyPhase - enthalpy balances for each phase, EnergyBalanceType.energyTotal - single energy balance for material, EnergyBalanceType.energyPhase - energy balances for each phase.}

    momentum_balance_type

    Indicates what type of momentum balance should be constructed, default - MomentumBalanceType.pressureTotal. Valid values: { MomentumBalanceType.none - exclude momentum balances, MomentumBalanceType.pressureTotal - single pressure balance for material, MomentumBalanceType.pressurePhase - pressure balances for each phase, MomentumBalanceType.momentumTotal - single momentum balance for material, MomentumBalanceType.momentumPhase - momentum balances for each phase.}

    has_phase_equilibrium

    Indicates whether terms for phase equilibrium should be constructed, default = False. Valid values: { True - include phase equilibrium terms False - exclude phase equilibrium terms.}

    has_pressure_change

    Indicates whether terms for pressure change should be constructed, default - False. Valid values: { True - include pressure change terms, False - exclude pressure change terms.}

    property_package

    Property parameter object used to define property calculations, default - useDefault. Valid values: { useDefault - use default package from parent model or flowsheet, PropertyParameterObject - a PropertyParameterBlock object.}

    property_package_args

    A ConfigBlock with arguments to be passed to a property block(s) and used when constructing these, default - None. Valid values: { see property package for documentation.}

    has_work_transfer

    True if model a has work transfer term.

    has_heat_transfer

    True if model has a heat transfer term.

  • initialize (dict) – ProcessBlockData config for individual elements. Keys are BlockData indexes and values are dictionaries with config arguments as keys.

  • idx_map (function) – Function to take the index of a BlockData element and return the index in the initialize dict from which to read arguments. This can be provided to override the default behavior of matching the BlockData index exactly to the index in initialize.

Returns:

(HelmTurbineStage) New instance

TurbineStageData Class#

class idaes.models_extra.power_generation.unit_models.helm.turbine_stage.HelmTurbineStageData(component)[source]#
build()[source]#

Add model equations to the unit model. This is called by a default block construnction rule when the unit model is created.

initialize_build(outlvl=0, solver=None, optarg=None)[source]#

Initialize the turbine stage model. This deactivates the specialized constraints, then does the isentropic turbine initialization, then reactivates the constraints and solves.

Parameters:
  • outlvl – sets output level of initialization routine

  • solver (str) – Solver to use for initialization

  • optarg (dict) – Solver arguments dictionary