WOLFRAM SYSTEM MODELER
ValveDiscreteRampValve for water/steam flows with discrete opening signal and ramp opening |
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Diagram
Wolfram Language
In[1]:=
SystemModel["Modelica.Fluid.Valves.ValveDiscreteRamp"]
Out[1]:=
Information
This information is part of the Modelica Standard Library maintained by the Modelica Association.
This model is similar to ValveDiscrete,
except that the valve opens gradually with an opening time Topen and closes gradually with
a closing time Tclose instead of doing so abruptly. This can help to avoid unrealistic phenomena such
as reversing flows when accurate fluid models with small compressiblity are employed.
Parameters (12)
| allowFlowReversal |
Value: system.allowFlowReversal Type: Boolean Description: = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
|---|---|
| dp_start |
Value: 0.01 * system.p_start Type: AbsolutePressure (Pa) Description: Guess value of dp = port_a.p - port_b.p |
| m_flow_start |
Value: system.m_flow_start Type: MassFlowRate (kg/s) Description: Guess value of m_flow = port_a.m_flow |
| m_flow_small |
Value: if system.use_eps_Re then system.eps_m_flow * system.m_flow_nominal else system.m_flow_small Type: MassFlowRate (kg/s) Description: Small mass flow rate for regularization of zero flow |
| show_T |
Value: true Type: Boolean Description: = true, if temperatures at port_a and port_b are computed |
| show_V_flow |
Value: true Type: Boolean Description: = true, if volume flow rate at inflowing port is computed |
| dp_nominal |
Value: Type: AbsolutePressure (Pa) Description: Nominal pressure drop at full opening |
| m_flow_nominal |
Value: Type: MassFlowRate (kg/s) Description: Nominal mass flowrate at full opening |
| opening_min |
Value: 0 Type: Real Description: Remaining opening if closed, causing small leakage flow |
| k |
Value: m_flow_nominal / dp_nominal Type: HydraulicConductance (kg/(s⋅Pa)) Description: Hydraulic conductance at full opening |
| Topen |
Value: Type: Time (s) Description: Time to fully open the valve |
| Tclose |
Value: Topen Type: Time (s) Description: Time to fully close the valve |
Connectors (3)
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port_a |
Type: FluidPort_a Description: Fluid connector a (positive design flow direction is from port_a to port_b) |
|---|---|---|
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port_b |
Type: FluidPort_b Description: Fluid connector b (positive design flow direction is from port_a to port_b) |
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open |
Type: BooleanInput Description: 'input Boolean' as connector |
Components (4)
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system |
Type: System Description: System wide properties |
|---|---|---|
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state_a |
Type: ThermodynamicState Description: State for medium inflowing through port_a |
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state_b |
Type: ThermodynamicState Description: State for medium inflowing through port_b |
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openingGenerator |
Type: TriggeredTrapezoid Description: Triggered trapezoid generator |
Used in Examples (1)
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Modelica.Fluid.Examples.AST_BatchPlant Model of an experimental batch plant |
Revisions
- Mar 2020 by Francesco Casella (based on ValveLinear and ValveDiscrete).