modelTrickleVent
Self regulating trickle vent
Extends from IDEAS.Fluid.BaseClasses.PartialResistance (Partial model for a hydraulic resistance).
Information
Model of a self regulating trickle vent.
The positive mass flow rate is limited to m_flow_nominal
at a pressure difference of dp_nominal.
For negative pressure differences the mass flow rate is not limited.
An optional control input can be enabled, which reduces the flow rate for the same pressure difference, but which does not affect the maximum flow rate.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | homotopyInitialization (from PartialResistance) | true | = true, use homotopy method |
| Modelica.Units.SI.MassFlowRate | m_flow_turbulent (from PartialResistance) | Turbulent flow if |m_flow| >= m_flow_turbulent | |
| Real | l | 0.0001 | Valve leakage, l=Kv(y=0)/Kv(y=1) |
| Real | k | if computeFlowResistance then m_flow_nominal_pos/sqrt(dp_nominal_pos) else 0 | Flow coefficient, k=m_flow/sqrt(dp), with unit=(kg.m)^(1/2) |
| Assumptions | |||
| Boolean | allowFlowReversal (from PartialTwoPort) | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
| Nominal condition | |||
| Modelica.Units.SI.MassFlowRate | m_flow_nominal (from PartialTwoPortInterface) | Nominal mass flow rate | |
| Modelica.Units.SI.PressureDifference | dp_nominal (from PartialResistance) | Pressure drop at nominal mass flow rate | |
| Advanced | |||
| Modelica.Units.SI.MassFlowRate | m_flow_small (from PartialTwoPortInterface) | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow |
| Boolean | from_dp (from PartialResistance) | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
| Boolean | linearized (from PartialResistance) | false | = true, use linear relation between m_flow and dp for any flow rate |
| Advanced › Diagnostics | |||
| Boolean | show_T (from PartialTwoPortInterface) | false | = true, if actual temperature at port is computed |
| Transition to laminar | |||
| Real | deltaM | 0.3 | Fraction of nominal mass flow rate where transition to turbulent occurs |
| Control | |||
| Boolean | use_y | false | =true, to enable control input |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | port_a (from PartialTwoPort) | Fluid connector a (positive design flow direction is from port_a to port_b) | |
| Modelica.Fluid.Interfaces.FluidPort_b | port_b (from PartialTwoPort) | Fluid connector b (positive design flow direction is from port_a to port_b) | |
| Modelica.Blocks.Interfaces.RealInput | y | Control input for trickle vent Kv value |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.MassFlowRate | m_flow (from PartialTwoPortInterface) | port_a.m_flow | Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) |
| Modelica.Units.SI.PressureDifference | dp (from PartialTwoPortInterface) | port_a.p - port_b.p | Pressure difference between port_a and port_b |
| Medium.ThermodynamicState | sta_a (from PartialTwoPortInterface) | if allowFlowReversal then Medium.setState_phX(port_a.p, noEvent(actualStream(port_a.h_outflow)), noEvent(actualStream(port_a.Xi_outflow))) else Medium.setState_phX(port_a.p, noEvent(inStream(port_a.h_outflow)), noEvent(inStream(port_a.Xi_outflow))) | Medium properties in port_a |
| Medium.ThermodynamicState | sta_b (from PartialTwoPortInterface) | if allowFlowReversal then Medium.setState_phX(port_b.p, noEvent(actualStream(port_b.h_outflow)), noEvent(actualStream(port_b.Xi_outflow))) else Medium.setState_phX(port_b.p, noEvent(port_b.h_outflow), noEvent(port_b.Xi_outflow)) | Medium properties in port_b |
Revisions
-
July 9, 2023, by Filip Jorissen:
Add control input. -
September 21, 2021, by Filip Jorissen:
First implementation.