PropPRVstatic

    PropPRVstatic

Library

Components/Valves/PressureValves

Description

The component PropPRVstatic is a model of a proportional pressure relief valve without dynamic characteristics. For all pressures exceeding opening pressure the valve opens and the flow increases linearly following the slope given by parameters Nominal volume flow and Nominal pressure difference.

The opening pressure is calculated by Input * Input scaling. If input should be in the range of 0 to 10 [V] and maximum opening pressure 200e5 Pa, Input scaling must be set to 20e5 [Pa/V] (200e5 / 10). If the opening pressure should be given directly by input, Input scaling must be set to 1. Please note: the upper value of opening pressure is not limited but only proportional to input.

If the valve is balanced (Balanced valve = true) the valve opens when the supply pressure exceeds the opening pressure:

Opening condition: fluidPortA.p > opening pressure + pAmbient

If the valve is not balanced (Balanced valve = false) the tank pressure is considered:

Opening condition: fluidPortA.p > opening pressure + fluidPortB.p

If Find exact opening point is set to true, the valve opens exactly at the time when the opening pressure is exceeded. If it is set to false, the valve may open earlier or later depending on simulation's step size. This setting avoids an event (and probably a slow down of simulation) by using noEvent().

The component part PRVstatic is not a model of a pressure relief valve according to its physical structure. It merely represents the characteristic behavior of a pressure relief valve. Therefore dynamic effects such as forces due to inertia will not be represented.

Parameters

PropPRVstatic_0

NameLabelDescriptionData TypeValid Values

mo_InputScaling

InputScaling

Input scaling

Scalar

mo_NominalVolumeFlow

NominalVolumeFlow

Nominal volume flow

Scalar

mo_NominalPressureDifference

NominalPressureDifference

Nominal pressure difference

Scalar

mo_ReferenceDensity

ReferenceDensity

Reference density for volume flow and pressure difference

Scalar

mo_deadVolume

deadVolume

Dead volume at ports

Scalar

mo_Balanced

Balanced

Balanced valve

Scalar

true
false

mo_exact

exact

Find exact opening point

Scalar

true
false

PropPRVstatic_1

NameLabelDescriptionData TypeValid Values

mo_forwardFluidProperties

forwardFluidProperties

Forward fluid properties between ports

Scalar

true
false

PropPRVstatic_2

NameLabelDescriptionData TypeValid Values

mo_volumeFlowA

volumeFlowA

volumeFlowA

Structure

mo_volumeFlowA/fixed

fixed

Cell of scalars

true
false

mo_volumeFlowA/start

start

Cell of scalars

mo_volumeFlowB

volumeFlowB

volumeFlowB

Structure

mo_volumeFlowB/fixed

fixed

Cell of scalars

true
false

mo_volumeFlowB/start

start

Cell of scalars

mo_pA

pA

pA

Structure

mo_pA/fixed

fixed

Cell of scalars

true
false

mo_pA/start

start

Cell of scalars

mo_pB

pB

pB

Structure

mo_pB/fixed

fixed

Cell of scalars

true
false

mo_pB/start

start

Cell of scalars

mo_deltap

deltap

deltap

Structure

mo_deltap/fixed

fixed

Cell of scalars

true
false

mo_deltap/start

start

Cell of scalars

mo_Input

Input

Input

Structure

mo_Input/fixed

fixed

Cell of scalars

true
false

mo_Input/start

start

Cell of scalars

Ports

NameTypeDescriptionIO TypeNumber

fluidPortA

implicit

Hydraulic port A

input

1

fluidPortB

implicit

Hydraulic port B

input

2

Input

implicit

Set value of opening pressure

input

3