Four way two position valve (TL)#

The block models the operation of a valve with four orifices in a thermal-hydraulic network. The valve is controlled by a single spool, the position of which is determined by the signal at port S. The block has two inlets — A and B and two outlets — P and T.

When ports are paired (AP, BP, AT, and BT), the block models fluid flow through four different orifices. Parameters affecting the flow through each orifice (spool stroke and maximum flow area) can be set identically for all four orifices or individually. The user also sets the initial spool offset (Valve close position parameter) relative to the position where the orifice is fully open.

The current spool displacement relative to its initial position is set by the signal through the automation port — at zero signal, all orifices are closed, and as the spool moves, they begin to open sequentially according to the orifice diameter and the specified offset. If the spool continues to move after the orifice is fully open (within the specified maximum stroke), saturation occurs, and the flow through the valve orifice does not increase.

The flow area of each orifice depends linearly on the spool position and is described by the formula (1):

(1)#\[A_{orifice}=\frac{A_{max}-A_{leak}}{\Delta S}\cdot S_{pos} + A_{leak}\]

where:

\(S_{pos}\) - calculated parameter based on the signal from the automation port Valve close position, [m];

\(\Delta S\) - parameter Valve travel, [m];

\(A_{max}\) - parameter Valve max area, [m\(^2\)];

\(A_{leak}\) - parameter Leakage area, [m\(^2\)].

1. Properties#

Property	Default Value	Description	Units of measurement
Positive spool position open connections: All closed; PA and BT; PA and PB; PB and AT; PA; PB; All opened	PA and BT	-	-
Negative spool position open connections: All closed; PA and BT; PA and PB; PB and AT; PA; PB; All opened	PA and BT	-	-
Characteristics for area: Identical; Different	Identical	-	-
Cross area calculation method: Linear; Tab	Linear	-	-
Valve travel PA	5e-3	Available, when `Characteristics for area` - `Different`	m
Valve travel PB	5e-3	Available, when `Characteristics for area` - `Different`	m
Valve travel AT	5e-3	Available, when `Characteristics for area` - `Different`	m
Valve travel BT	5e-3	Available, when `Characteristics for area` - `Different`	m
Valve max area PA	1e-4	Available, when `Characteristics for area` - `Different`	m\(^2\)
Valve max area PB	1e-4	Available, when `Characteristics for area` - `Different`	m\(^2\)
Valve max area AT	1e-4	Available, when `Characteristics for area` - `Different`	m\(^2\)
Valve max area BT	1e-4	Available, when `Characteristics for area` - `Different`	m\(^2\)
Valve travel	5e-3	Available, when `Characteristics for area` - `Identical` and `Cross area calculation method` - `Linear`	m
Valve max area	1e-4	Available, when `Characteristics for area` - `Identical` and `Cross area calculation method` - `Linear`	m\(^2\)
Leakage area	1e-10	Available, when `Cross area calculation method` - `Linear`	m\(^2\)
Area port	0.1	-	m\(^2\)
Reynolds critical numbers	150	-	-
Smoothing factor	0.01	Available, when `Cross area calculation method` - `Linear`	-
Pressure recovery	0.64	-	-
Valve close position PA	5e-3	-	m
Valve close position PB	5e-3	-	m
Valve close position AT	5e-3	-	m
Valve close position BT	5e-3	-	m
Spool position vector	0, 0.02, 0.04, 0.07, 0.017	Available, when `Characteristics for area` - `Identical` and `Cross area calculation method` - `Tab`	m
Valve cross area vector	1e-06, 1e-05, 1e-04, 1e-3, 3e-3	Available, when `Characteristics for area` - `Identical` and `Cross area calculation method` - `Tab`	m\(^2\)
Spool position vector PA	0, 0.02, 0.04, 0.07, 0.017	Available, when `Characteristics for area` - `Different` and `Cross area calculation method` - `Tab`	m
Spool position vector PB	0, 0.02, 0.04, 0.07, 0.017	Available, when `Characteristics for area` - `Different` and `Cross area calculation method` - `Tab`	m
Spool position vector AT	0, 0.02, 0.04, 0.07, 0.017	Available, when `Characteristics for area` - `Different` and `Cross area calculation method` - `Tab`	m
Spool position vector BT	0, 0.02, 0.04, 0.07, 0.017	Available, when `Characteristics for area` - `Different` and `Cross area calculation method` - `Tab`	m
Valve cross area vector PA	1e-06, 1e-05, 1e-04, 1e-3, 3e-3	Available, when `Characteristics for area` - `Different` and `Cross area calculation method` - `Tab`	m\(^2\)
Valve cross area vector PB	1e-06, 1e-05, 1e-04, 1e-3, 3e-3	Available, when `Characteristics for area` - `Different` and `Cross area calculation method` - `Tab`	m\(^2\)
Valve cross area vector AT	1e-06, 1e-05, 1e-04, 1e-3, 3e-3	Available, when `Characteristics for area` - `Different` and `Cross area calculation method` - `Tab`	m\(^2\)
Valve cross area vector BT	1e-06, 1e-05, 1e-04, 1e-3, 3e-3	Available, when `Characteristics for area` - `Different` and `Cross area calculation method` - `Tab`	m\(^2\)

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Port A	Input	-	-	Thermohydraulics
Port B	Input	-	-	Thermohydraulics
Spool displacement	Input	-	m	Automation
Port P	Output	-	-	Thermohydraulics
Port T	Output	-	-	Thermohydraulics

In order to see the connection capabilities of the block, you need to go to page Description of block ports