functionequalPercentage
Valve opening characteristics for equal percentage valve
Extends from Modelica.Icons.Function (Icon for functions).
Information
This function computes the opening characteristics of an equal percentage valve.
The function is used by the model Buildings.Fluid.Actuators.Valves.TwoWayEqualPercentage.
For y < delta/2, the valve characteristics is linear. For y > 3*delta/2
the valve characteristics is equal percentage. In between, a cubic spline is used to ensure
that the valve characteristics is once continuously differentiable with respect to y.
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | y | Valve opening signal, y=1 is fully open | |
| Real | R | Rangeability, R=50...100 typically | |
| Real | l | Valve leakage, l=Kv(y=0)/Kv(y=1) | |
| Real | delta | Range of significant deviation from equal percentage law |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | phi | Ratio actual to nominal mass flow rate, phi=Cv(y)/Cv(y=1) |
Revisions
-
April 11, 2016 by Michael Wetter:
Corrected wrong hyperlink in documentation for issue 450. -
March 30, 2011 by Michael Wetter:
AddedzeroDerivativekeyword. -
June 5, 2008 by Michael Wetter:
First implementation.