2-Way Directional Valve (TL)

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Two-line flow control valve in a thermal liquid network.

2 way directional valve tl

Description

Block 2-Way Directional Valve (TL) represents a two-line valve, such as a shut-off valve. Use this block to model a flow reducing control element that responds to pressure in another part of the system.

The block uses a variable orifice to control flow between ports A and B. The signal at port S determines the movement of the spool to open or close the valve.

It is possible to set the flow characteristic of the distributor channels in the Orifice parameterization as a linear dependence or as a tabular function provided by the user.

Linear parameterization

If Linear - Area vs. spool travel is selected for the Orifice parameterization, the flow area of the channel depends linearly on the spool travel and the value supplied to the port S:

where

- spool position entering the S port, ;
- value of parameters of spool travel between closed and open orifice (value of parameter Spool travel between closed and open orifice);
- leakage area (value of parameter Leakage area);
- value of the parameter of maximum orifice area (value of the parameter Maximum orifice area).

Note the linear growth from to in the figure:

Static

When the orifice is in the nearly open or nearly closed position in the linear parameterization, you can maintain the numerical stability of the simulation by adjusting the smoothing factor - the value of the Smoothing factor parameter. If the Smoothing factor parameter value is not zero, a smooth change in the cross-sectional area between and is ensured.

Tabular parameterization

If Tabulated data - Area vs. spool travel is selected for Orifice parameterization, the block uses the Spool travel vector and the parameters of the valve area vector to determine the relationship between and by interpolation. and are the first and last elements of the Opening area vector respectively.

Static

If Tabulated data - Volumetric flow rate vs. spool travel and pressure drop is selected for Orifice parameterization, the block uses the volumetric flow rate table Volumetric flow rate table, q(ds,dp), the relative pressure drop vector Pressure drop vector, dp and the spool travel vector Spool travel vector, ds to determine the volumetric flow rate, .

Static

If Tabulated data - Mass flow rate vs. opening and pressure drop is selected for parameterization Orifice parameterization, the block uses the mass flow rate table Mass flow rate table, mdot(ds,dp), the relative pressure drop vector Pressure drop vector, dp and the spool travel vector Spool travel vector, ds to determine the mass flow rate, .

Static

Ports

Conserving

# A — thermal liquid port
thermal liquid

Details

Thermal liquid port, corresponds to valve inlet or outlet.

Program usage name

port_a

# B — thermal liquid port
thermal liquid

Details

Thermal liquid port, corresponds to valve inlet or outlet.

Program usage name

port_b

Input

# S — distributor spool position
scalar

Details

Inlet port of the distributor spool position in m, specifying the valve cross-sectional area. A positive value causes the valve to open.

Data types	`Float64`.
Complex numbers support	No

Parameters

Model Parameterization

# Orifice parameterization — method for calculating the valve cross-sectional area
Linear - Area vs. spool travel | Tabulated data - Area vs. spool travel | Tabulated data - Volumetric flow rate vs. spool travel and pressure drop | Tabulated data - Mass flow rate vs. spool travel and pressure drop

Details

A method for calculating valve cross-sectional area in modelling.

Values	`Linear - Area vs. spool travel` \| `Tabulated data - Area vs. spool travel` \| `Tabulated data - Volumetric flow rate vs. spool travel and pressure drop` \| `Tabulated data - Mass flow rate vs. spool travel and pressure drop`
Default value	`Linear - Area vs. spool travel`
Program usage name	`orifice_parameterization`
Evaluatable	No

# Spool position at maximum orifice area — spool position at maximum area
m | cm | ft | in | km | mi | mm | um | yd

Details

Position of the spool element when the valve is fully open.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.005 m`
Program usage name	`max_control_displacement`
Evaluatable	Yes

# Spool travel between closed and open orifice — maximum spool stroke
m | cm | ft | in | km | mi | mm | um | yd

Details

Spool stroke between the closed and open states of the valve.

Dependencies

To use this parameter, set the Orifice parameterization parameters to Linear - area vs. spool travel.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.005 m`
Program usage name	`delta_control_displacement`
Evaluatable	Yes

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

Details

Maximum valve cross-sectional area during the simulation.

Dependencies

To use this parameter, set the Orifice parameterization parameters to Linear - area vs. spool travel.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`0.0001 m^2`
Program usage name	`max_area`
Evaluatable	Yes

# Leakage area — leakage area through the valve 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 less than this value is maintained at the specified leakage area. This parameter contributes to the stability of the numerical solution by maintaining flow continuity.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Linear - area vs. spool travel'.

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

# Spool travel vector — spool position vector
m | cm | ft | in | km | mi | mm | um | yd

Details

Vector of spool positions. The dimension of the vector corresponds to the Orifice area vector. A positive value corresponds to an open valve. The values are listed in ascending order and the first element must be equal to `0'. Linear interpolation is used between the data points in the table.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Tabulated data - Area vs. spool travel'.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 2.0e-3, 4.0e-3, 7.0e-3, 1.7e-2] m`
Program usage name	`control_displacement_vector_1D`
Evaluatable	Yes

# Orifice area vector — vector of valve cross-sectional area values
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

Vector of valve cross-sectional area values for the tabular parameterization of the valve area. The dimension of the vector corresponds to the Spool travel vector. The values are listed in ascending order. The first element is the leakage area, the last element is the maximum cross-sectional area of the channel. Linear interpolation is used between data points.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Tabulated data - Area vs. spool travel'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`[1.0e-9, 2.0352e-7, 4.0736e-5, 1.1438e-4, 3.4356e-4] m^2`
Program usage name	`restriction_area_vector_1D`
Evaluatable	Yes

# Discharge coefficient — flow coefficient

Details

The correction factor is the ratio of the actual mass flow rate to the theoretical mass flow rate through the distributor.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Linear - area vs. spool travel' or `Tabulated data - Area vs. spool travel'.

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

# Critical Reynolds number — upper limit of Reynolds number for laminar flow

Details

Upper limit of Reynolds number for laminar flow through an orifice.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Linear - area vs. spool travel' or `Tabulated data - Area vs. spool travel'.

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.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Linear - area vs. spool travel'.

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

# Pressure recovery — whether to take into account the increase in pressure when expanding the area

Details

Whether to take into account the pressure increase when the fluid flows from a region with a smaller cross-sectional area to a region with a larger cross-sectional area.

If Pressure recovery is unchecked, this pressure increase is not taken into account.

Default value	`false (switched off)`
Program usage name	`pressure_recovery`
Evaluatable	No

# Spool travel vector, ds — spool position vector
m | cm | ft | in | km | mi | mm | um | yd

Details

Spool position vector for tabular parameterization of the flow rate. The dimension of the spool position vector corresponds to the differential pressure vector Pressure drop vector, dp and the volumetric flow rate table Volumetric flow rate table, q(ds,dp) or mass flow rate table Mass flow rate table, mdot(ds,dp). The values are listed in ascending order and the first element must be equal to 0. Linear interpolation is used to calculate intermediate values.

Dependencies

To use this parameter, set the Orifice parameterization parameter to Tabulated data -Volumetric flow rate vs. spool travel and pressure drop or Tabulated data - Mass flow rate vs. spool travel and pressure drop.

Values	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`[0.0, 0.002, 0.004, 0.007, 0.017] 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 flow parameterization. The dimension of the differential pressure vector corresponds to the spool position vector Spool travel vector, ds and the volumetric flow rate table Volumetric flow rate table, q(ds,dp) or mass flow rate table Mass flow rate table, mdot(ds,dp). The values are listed in ascending order and must be greater than 0. Linear interpolation is used to calculate intermediate values.

Dependencies

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(ds,dp) — table of volumetric flow rates
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 to of volume flow rates corresponding to differential pressure and spool position values. and are the dimensions of the corresponding vectors:

- number of elements in the spool position vector Spool travel vector, ds.
- number of elements in the pressure drop vector Pressure drop vector, dp.

Dependencies

To use this parameter, set the Orifice parameterization parameters to Tabulated data - Volumetric flow rate vs. spool travel 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	`1.0e-3 * [1.7e-05 2.0e-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] m^3/s`
Program usage name	`Vdot_matrix_2D`
Evaluatable	Yes

# Mass flow rate table, mdot(ds,dp) — mass flow rate table
kg/s | N*s/m | N/(m/s) | lbf/(ft/s) | lbf/(in/s)

Details

Matrix to of mass flow rates corresponding to differential pressure and spool position values. and are dimensions of the corresponding vectors:

- number of elements in the spool position vector Spool travel vector, ds.
- number of elements in the pressure drop vector Pressure drop vector, dp.

Dependencies

To use this parameter, set the Orifice parameterization parameters to Tabulated data - Mass flow rate vs. spool travel and pressure drop.

Values	`kg/s` \| `N*s/m` \| `N/(m/s)` \| `lbf/(ft/s)` \| `lbf/(in/s)`
Default value	`[1.7e-05 2.0e-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] kg/s`
Program usage name	`mdot_matrix_2D`
Evaluatable	Yes

Details

Temperature for which the tabulated mass flow data is set.

Dependencies

To use this parameter, set the Orifice parameterization parameters to Tabulated data - Mass flow rate vs. spool travel and pressure drop.

Values	`K` \| `degC` \| `degF` \| `degR` \| `deltaK` \| `deltadegC` \| `deltadegF` \| `deltadegR`
Default value	`293.15 K`
Program usage name	`T_inflow_ref`
Evaluatable	Yes

# Reference inflow pressure — pressure for which the tabulated mass flow rate data are set
Pa | GPa | MPa | atm | bar | kPa | ksi | psi | uPa | kbar

Details

The pressure for which the tabulated mass flow data is set. The unit uses this parameter to calculate the corresponding density.

Dependencies

To use this parameter, set the Orifice parameterization parameters to Tabulated data - Mass flow rate vs. spool travel and pressure drop.

Values	`Pa` \| `GPa` \| `MPa` \| `atm` \| `bar` \| `kPa` \| `ksi` \| `psi` \| `uPa` \| `kbar`
Default value	`0.101325 MPa`
Program usage name	`p_inflow_ref`
Evaluatable	Yes

# Cross-sectional area at ports A and B — area at the inlet or outlet of the valve
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The cross-sectional area at the inlet and outlet of orifices A and B. This area is used when calculating the mass flow rate through the orifice.

Dependencies

To use this parameter, set the Orifice parameterization parameters to `Linear - area vs. spool travel' or `Tabulated data - Area vs. spool travel'.

Values	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`0.01 m^2`
Program usage name	`port_area`
Evaluatable	Yes