modelTurbineStodola
Gas Turbine
Extends from BaseClasses.TurbineBase (Gas Turbine).
Information
This model extends the Turbine_Base model with the calculation of the performance parameters, mass flowrate, pressure ratio and efficiency.This method is based on the Stodola's law, which calculates PR as function of the inlet conditions, i.e. mass flowrate, inlet temperature and pressure.
Modelling options
The following options are available to define Stodola's constant K:
- NominalCondition = true: Stodola's constant K is specified by the nominal operating point (wnom,Tstart_in,pstart_in,pstart_out)
- NominalCondition = false: Stodola's constant K is used directly.
The following options are available to define the efficiency eta:
- fixedEta = true: the efficiency is explicitly supplied as a parameter.
- fixedEta = false: the efficiency is a function of the pressure ratio PR and of the referred speed N_T. The function is defined by interpolation of the table tableEta, where N_T represents the first row and PR the first column of the table. The interpolation is performed by a Modelica.Blocks.Tables.CombiTable2D model.
The following options are available to select the way of definition of the table:
- Table = 0: the table is explicitly supplied as a matrix parameter.
- Table = 1: the table is read from a file; the string fileName contains the path to the files where the table is stored, either in ASCII or Matlab binary format.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | explicitIsentropicEnthalpy (from TurbineBase) | true | isentropicEnthalpy function used |
| SI.PerUnit | eta_mech (from TurbineBase) | 0.98 | mechanical efficiency |
| Medium.Temperature | Tdes_in (from TurbineBase) | inlet design temperature | |
| Boolean | allowFlowReversal (from TurbineBase) | system.allowFlowReversal | = true to allow flow reversal, false restricts to design direction |
| Boolean | NominalCondition | true | true: K is evaluated from design operating point; false: K is set as a parameter |
| SI.AngularVelocity | Ndesign | Design velocity | |
| Real[:,:] | tableEta | fill(0, 2, 2) | Table for eta(N_T,PR) |
| String | fileName | "NoName" | File where matrix is stored |
| TableTypes | Table | TableTypes.matrix | Selection of the way of definition of table matrix |
| Boolean | fixedEta | true | true:eta is a parameter, false:eta is calculated from table |
| SI.PerUnit | eta_nom | 0.8 | Nominal efficiency value |
| Real | K | Stodola's constant | |
| Medium.MassFlowRate | wnom | Nominal mass flow rate | |
| Initialisation | |||
| Medium.AbsolutePressure | pstart_in (from TurbineBase) | inlet start pressure | |
| Medium.AbsolutePressure | pstart_out (from TurbineBase) | outlet start pressure | |
| Medium.Temperature | Tstart_in (from TurbineBase) | Tdes_in | inlet start temperature |
| Medium.Temperature | Tstart_out (from TurbineBase) | outlet start temperature | |
| Medium.MassFraction[Medium.nX] | Xstart (from TurbineBase) | Medium.reference_X | start gas composition |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Mechanics.Rotational.Interfaces.Flange_a | shaft_a (from TurbineBase) | ||
| Modelica.Mechanics.Rotational.Interfaces.Flange_b | shaft_b (from TurbineBase) | ||
| FlangeA | inlet (from TurbineBase) | ||
| FlangeB | outlet (from TurbineBase) |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| ThermoPower.System | system (from TurbineBase) | System wide properties | |
| Medium.BaseProperties | gas_in (from TurbineBase) | ||
| Medium.BaseProperties | gas_iso (from TurbineBase) | ||
| SI.Angle | phi (from TurbineBase) | shaft rotation angle | |
| SI.Torque | tau (from TurbineBase) | net torque acting on the turbine | |
| SI.AngularVelocity | omega (from TurbineBase) | shaft angular velocity | |
| Medium.MassFlowRate | w (from TurbineBase) | Gas flow rate | |
| Medium.SpecificEntropy | s_in (from TurbineBase) | Inlet specific entropy | |
| Medium.SpecificEnthalpy | hout_iso (from TurbineBase) | Outlet isentropic enthalpy | |
| Medium.SpecificEnthalpy | hout (from TurbineBase) | Outlet enthalpy | |
| Medium.AbsolutePressure | pout (from TurbineBase) | Outlet pressure | |
| SI.PerUnit | PR (from TurbineBase) | pressure ratio | |
| SI.PerUnit | eta (from TurbineBase) | isoentropic efficiency | |
| Real | N_T | Referred speed | |
| Real | N_T_design | Referred design speed | |
| Real | phic | Flow number | |
| Modelica.Blocks.Tables.CombiTable2D | Eta |
Revisions
- 13 Apr 2005
by Francesco Casella:
Turbine model restructured using inheritance.
First release.