model PressureControlValve
parameter Modelica.SIunits.Pressure SetPressure = 1e+7 "Set pressure (relative value)";
parameter Modelica.SIunits.Pressure DeviationPA = -500000 "Deviation P-A";
parameter Modelica.SIunits.Pressure DeviationAT = 500000 "Deviation A-T";
parameter Real gain = 1 "Controller gain";
extends HydraulicsByFluidon.Components.Valves.Base.PartialPressureValve_32;
protected
parameter Modelica.SIunits.AbsolutePressure SetPressureAbs = SetPressure + environment.pAmbient;
equation
if noEvent(portA.p <= SetPressureAbs) then
ssU = min(1, (SetPressureAbs + volumeFlowP / NominalVolumeFlow * DeviationPA - portA.p) * (1e-5) * gain);
else
ssU = max(-1, (SetPressureAbs - volumeFlowT / NominalVolumeFlow * DeviationAT - portA.p) * (1e-5) * gain);
end if;
annotation (
Icon(
coordinateSystem(
extent = {
{-100, -100},
{100, 100}},
preserveAspectRatio = false),
graphics = {
Line(
origin = {40, -20},
points = {
{0, 0},
{4, 20},
{12, -20},
{20, 20},
{28, -20},
{36, 20},
{44, -20},
{48, 0}})}),
Documentation(info = "<html>\n <p>\n The component PressureControlValve is a model of a 3-port pressure control valve. \n It maintains a largely constant outlet pressure even at a variable (higher) supply pressure. In addition to a 2-port pressure reducing valve \n it also reduces the outlet pressure to tank.\n </p>\n <p>\n <center><img src=\"modelica://HydraulicsByFluidon/Resources/Images/Components/Valves/PressureValves/PressureControlValve.png\"></center>\n </p>\n <p>\n If supply pressure <var>pA</var> is less than <var>Set pressure (relative value)</var> the valve acts like an orifice \n with the characteristics <var>Nominal volume flow</var> and <var>Nominal pressure difference</var>.\n </p>\n <p>\n For all pressures deviating from <var>Set pressure (relative value)</var> the valve opens and \n the flow increases linearly following the slope given by parameters <var>Nominal volume flow</var> and \n <var>Pressure drop</var>. For flow P->A the outlet pressure deviates by <var>Deviation P-A</var> @ <var>Nominal volume flow</var>\n and by <var>Deviation P-A</var> @ -<var>Nominal volume flow</var> for flow A->T.\n </p>\n <p>\n <center><img src=\"modelica://HydraulicsByFluidon/Resources/Images/Components/Valves/PressureValves/PressureControlValveSketch.png\"></center>\n </p>\n <p>\n The component PressureControlValve is not a model of a pressure control valve according to its \n physical structure. It merely represents the characteristic behavior of a pressure control \n valve. Therefore dynamic effects such as forces due to inertia will not be represented.\n </p>\n </html>"));
end PressureControlValve;