Pressure-Compensated 3-Way Flow Control Valve (IL)

Three-way flow controller in an isothermal liquid network.

pressure compensated 3 way flow control valve (il)

Description

The Pressure-Compensated 3-Way Flow Control Valve (IL) unit controls and maintains a constant flow pressure of isothermal liquid. When the control control pressure meets or exceeds the Set orifice pressure differential, the relief component of the downstream compensator valve opens, compensating for pressure.

The flow control valve opens and closes according to the controlling physical signal of the S port, which determines the orifice area of the downstream unit. A positive signal opens the valve. After opening, the compensated fluid flows through port R to the other part of the network.

For pressure compensated flow control without draining, see block Pressure-Compensated Flow Control Valve (IL).

Orifice parameterization

The Orifice parameterization parameter offers three valve models:

`Linear - Area vs. control member position' - an analytical model in which the relationship between the control element and the valve opening area is linear.
`Tabulated data - Area vs. control member position' - a model in which the control member position and opening area are determined by a user-defined table. Points between the user data are calculated by linear interpolation, points outside the table are determined by extrapolation to the nearest neighbour value.
`Tabulated data - Volumetric flow rate vs. control member position and pressure drop' is a model in which the control member position, orifice pressure drop and volumetric flow rate are defined in a user-defined table. Points between the user data are calculated by linear interpolation, points outside the table are determined by extrapolation to the nearest neighbour value

Numerically smoothed area and pressure

If the orifice parameterization is linear, the computational robustness of the simulation at the extremes of the range of orifice area and valve pressure is supported by the Smoothing factor parameter, whose value must be greater than 0 and less than 1. If the Smoothing factor parameter is non-zero, the Pressure-Compensated 3-Way Flow Control Valve (IL) block applies the smoothing function to all calculated areas and pressures, but it primarily affects the simulation at the extremes of these ranges.

If smoothing is enabled, the orifice area varies smoothly between the Leakage area and Maximum orifice area parameters. The unit smooths the valve pressure between Set orifice pressure differential and the sum of Set orifice pressure differential and Pressure compensator valve regulation range.

Block diagram

The Pressure-Compensated 3-Way Flow Control Valve (IL) block is built from the blocks Pressure Compensator Valve (IL) and Orifice (IL). Schematic diagram of a three-way flow control valve:

pressure compensated 3 way flow control valve (il) 1

Ports

Conserving

# A — isothermal liquid port
isothermal liquid

Details

The fluid inlet or outlet port of a three-way valve.

Program usage name

port_a

# B — isothermal liquid port
isothermal liquid

Details

A port of entry or exit of a fluid into an orifice.

Program usage name

port_b

# R — isothermal liquid port of the reducing valve
isothermal liquid

Details

Fluid outlet port of the reducing valve.

Program usage name

reducing_valve_port

Input

# S — actuator displacement
scalar

Details

Input port of the control travel that specifies the opening of the hole, in m.

Data types	`Float64`.
Complex numbers support	No

Parameters

# Orifice parameterization — hole modelling technique
Linear - Area vs. control member position | Tabulated data - Area vs. control member position | Tabulated data - Volumetric flow rate vs. control member position and pressure drop

Details

A method for modelling a hole opening. The orifice is either parameterised linearly, which relates the orifice area to the position of the control element; using user data, which relates the orifice area to the position of the control element; or using an array of data, which relates the valve flow rate to the position of the control element and the pressure drop across the valve.

Values	`Linear - Area vs. control member position` \| `Tabulated data - Area vs. control member position` \| `Tabulated data - Volumetric flow rate vs. control member position and pressure drop`
Default value	`Linear - Area vs. control member position`
Program usage name	`restriction_parameterization`
Evaluatable	No

# Control member position at closed orifice — control element offset
m | cm | ft | in | km | mi | mm | um | yd

Details

Offset of the regulating element when the orifice is fully open. A positive non-zero value indicates a partially closed orifice. A negative non-zero value indicates a closed orifice that remains open at the initial offset set by the physical signal at port S.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.0 m`
Program usage name	`min_control_displacement`
Evaluatable	Yes

# Control member travel between closed and opened orifice — maximum travel of the control element
m | cm | ft | in | km | mi | mm | um | yd

Details

The stroke of the control element at which the orifice is fully open.

Dependencies

To enable this parameter, set Orifice parameterization to Linear - Area vs. control member position.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`5e-3 m`
Program usage name	`delta_control_displacement`
Evaluatable	Yes

# Maximum orifice area — maximum cross-sectional area of the hole
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The cross-sectional area of the orifice in the fully open position. This parameter is used as an upper limit for area and pressure calculations during simulation.

Dependencies

To enable this parameter, set Orifice parameterization to `Linear - Area vs. control member position'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`8e-5 m^2`
Program usage name	`max_restriction_area`
Evaluatable	Yes

# Control member position vector — position vector of the control element
m | cm | ft | in | km | mi | mm | um | yd

Details

Control element position vector for tabular parameterization of the hole opening area. The elements of the vector must match one-to-one with the elements of the Orifice area vector. The elements are listed in ascending order and the first element must be equal to 0. Linear interpolation is used between tabular data points.

Dependencies

To enable this parameter, set Orifice parameterization to Tabulated data - Area vs. control member position.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 2e-3, 7e-3] m`
Program usage name	`control_displacement_vector_1D`
Evaluatable	Yes

# Orifice area vector — hole opening area vector
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Valve orifice area vector for tabular parameterization of the valve opening area. The elements of the vector must match one-to-one with the elements of the Control member position vector. The elements are listed in ascending order and must be greater than `0'.

Dependencies

To enable this parameter, set Orifice parameterization to `Tabulated data - Area vs. control member position'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`[1e-9, 4e-9, 1e-5] m^2`
Program usage name	`restriction_area_vector_1D`
Evaluatable	Yes

# Control member position vector, s — control element displacement vector
m | cm | ft | in | km | mi | mm | um | yd

Details

Control displacement vector for volumetric flow rate table parameterization. The position vector of the controls forms an independent axis with the parameter Pressure drop vector, dp for the dependent parameter Volumetric flow rate table, q(s,dp). A positive offset corresponds to valve opening. The values are listed in ascending order and the first element must be equal to 0. Linear interpolation is used between the tabulated data points.

Dependencies

To enable this parameter, set Orifice parameterization to Tabulated data - Volumetric flow rate vs. control member position and pressure drop.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 2e-3, 4e-3, 7e-3, 1.7e-2] m`
Program usage name	`control_displacement_vector_2D`
Evaluatable	Yes

# Pressure drop vector, dp — vector of differential pressure values
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

Vector of differential pressure values for tabular parameterization of the valve opening area. The differential pressure vector forms an independent axis with the Control member position vector, s for the dependent parameter Volumetric flow rate table, q(s,dp). Values are listed in ascending order and must be greater than 0. Linear interpolation is used between tabular data points.

Dependencies

To enable this parameter, set Orifice parameterization to Tabulated data - Volumetric flow rate vs. control member position and pressure drop.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`[0.3, 0.5, 0.7] MPa`
Program usage name	`delta_p_vector_2D`
Evaluatable	Yes

# Volumetric flow rate table, q(s,dp) — volume flow rate array
m^3/s | m^3/h | cm^3/s | mm^3/s | ft^3/s | lpm | l/s | gpm | gal/s | gal/h

Details

Matrix of volume flow rates based on independent values of differential pressure and position of the control element. and are the dimensions of the corresponding vectors:

- number of elements in the Pressure drop vector, dp;
- number of elements in the Control member position vector, s.

Dependencies

To enable this parameter, set Orifice parameterization to Tabulated data - Volumetric flow rate vs. control member position and pressure drop.

Values	`m^3/s` \| `m^3/h` \| `cm^3/s` \| `mm^3/s` \| `ft^3/s` \| `lpm` \| `l/s` \| `gpm` \| `gal/s` \| `gal/h`
Default value	`[1.7e-05 2e-05 2.6e-05; 0.0035 0.0045 0.0053; 0.7 0.9 1.06; 1.96 2.5 3.0; 6.0 7.7 9.13]*1e-3 m^3/s`
Program usage name	`Vdot_matrix_2D`
Evaluatable	Yes

# Set orifice pressure differential — compensator valve threshold
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

The amount of differential pressure that causes the valve to open or close.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.6 MPa`
Program usage name	`delta_p_set`
Evaluatable	Yes

# Pressure compensator valve regulation range — area of the fully open pressure compensator valve
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

The cross-sectional area of the valve orifice in the fully open position. This parameter is used as an upper limit for area and pressure calculations during simulation.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.1 MPa`
Program usage name	`p_regulation_range`
Evaluatable	Yes

# Pressure compensator valve maximum area — working pressure range of the pressure compensation valve
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The working pressure range of the valve. The pressure control range lies between Set orifice pressure differential and the maximum working pressure of the valve.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`12e-5 m^2`
Program usage name	`max_compensator_area`
Evaluatable	Yes

# Leakage area — clearance area in fully closed position
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The sum of all clearances when the valve is in the fully closed position. Any area smaller than this value is maintained at the specified leakage area. This contributes to computational stability by maintaining continuity of flow.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1e-10 m^2`
Program usage name	`leakage_area`
Evaluatable	Yes

# Discharge coefficient — flow coefficient

Details

Correction factor that takes into account the rarefaction losses in theoretical flows.

Default value	`0.64`
Program usage name	`C_d`
Evaluatable	Yes

# Critical Reynolds number — upper limit of Reynolds number in the laminar flow regime

Details

Upper limit of the Reynolds number in laminar flow through the valve.

Default value	`150.0`
Program usage name	`Re_critical`
Evaluatable	Yes

# Smoothing factor — numerical smoothing factor

Details

A continuous smoothing factor that introduces a level of gradual change based on the flow characteristic when the valve is in the nearly open and nearly closed positions. Set a non-zero value less than one to increase the stability of the simulation in these modes.

Default value	`0.01`
Program usage name	`smoothing_factor`
Evaluatable	Yes