modelSteamTurbineUnit
Extends from Icons.Water.SteamTurbineUnit.
Information
This model describes a simplified steam turbine unit, with a high pressure and a low pressure turbine.
The inlet flowrate is proportional to the inlet pressure, and to the partialArc signal if the corresponding connector is wired. In this case, it is assumed that the flow rate is reduced by partial arc admission, not by throttling (i.e., no loss of thermodynamic efficiency occurs). To simulate throttling, insert a valve before the turbine unit inlet.
The model assumes that a fraction hpFraction of the available hydraulic power is converted by the HP turbine with a time constant of T_HP, while the remaining part is converted by the LP turbine with a time constant of L_HP.
This model does not include any shaft inertia by itself; if that is needed, connect a Modelica.Mechanics.Rotational.Inertia model to one of the shaft connectors.
The model requires the Modelica.Media library (ThermoFluid does not compute the isentropic enthalpy correctly).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Medium.AbsolutePressure | pnom | Inlet nominal pressure | |
| Medium.MassFlowRate | wnom | Inlet nominal flow rate | |
| SI.PerUnit | eta_iso | Isentropic efficiency [PerUnit] | |
| SI.PerUnit | eta_mech | 0.98 | Mechanical efficiency [PerUnit] |
| SI.PerUnit | hpFraction | Fraction of power provided by the HP turbine [PerUnit] | |
| SI.Time | T_HP | Time constant of HP mechanical power response | |
| SI.Time | T_LP | Time constant of LP mechanical power response | |
| Boolean | allowFlowReversal | system.allowFlowReversal | = true to allow flow reversal, false restricts to design direction |
| Initialization | |||
| SI.MassFlowRate | wstart | wnom | Flow rate start value |
| Medium.AbsolutePressure | pstartin | pnom | Inlet start pressure |
| Medium.SpecificEnthalpy | hstartin | Inlet enthalpy start value | |
| Medium.SpecificEnthalpy | hstartout | Outlet enthalpy start value | |
| SI.Power | P_HPstart | wstart*(hstartin - hstartout)*hpFraction | HP turbine power start value |
| SI.Power | P_LPstart | wstart*(hstartin - hstartout)*(1 - hpFraction) | LP turbine power start value |
| ThermoPower.Choices.Init.Options | initOpt | system.initOpt | Initialization option |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| FlangeA | inlet | ||
| FlangeB | outlet | ||
| Modelica.Mechanics.Rotational.Interfaces.Flange_a | shaft_a | ||
| Modelica.Mechanics.Rotational.Interfaces.Flange_b | shaft_b | ||
| Modelica.Blocks.Interfaces.RealInput | partialArc |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| ThermoPower.System | system | System wide properties | |
| Medium.ThermodynamicState | fluidState_in | ||
| Medium.MassFlowRate | w | Mass flowrate | |
| SI.Angle | phi | Shaft rotation angle | |
| SI.AngularVelocity | omega | Shaft angular velocity | |
| SI.Torque | tau | Net torque acting on the turbine | |
| Real | Kv | Turbine nominal admittance at full throttle | |
| Medium.SpecificEnthalpy | hin | Inlet enthalpy | |
| Medium.SpecificEnthalpy | hout | Outlet enthalpy | |
| Medium.SpecificEnthalpy | hiso | Isentropic outlet enthalpy | |
| SI.Power | Pm | Mechanical power input | |
| SI.Power | P_HP | Mechanical power produced by the HP turbine | |
| SI.Power | P_LP | Mechanical power produced by the LP turbine |
Contents
| Name | Description |
|---|---|
 Medium |
Revisions
- 16 Dec 2004
by Francesco Casella:
Standard medium definition added. - 4 Aug 2004
by Francesco Casella:
First release.