Four way three position hydraulic control valve (TL)#

The Four way three position hydraulic control valve (TL) models a valve with four orifices in a thermal-hydraulic network, typically between an actuator, pump, and tank. 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—P and T—and two outlets — A and B, as well as two hydraulic control ports — L and R.

The block consists of four hydraulic orifices paired—PA, PB, TA, and TB. See the mathematical model in the block Orifice (TL).

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

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

where:

\(S_{min}\) - parameter Spool min position, [m];

\(\Delta S\) - parameter Spool stroke, [m];

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

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

\(\epsilon\) - Opening Orientation.

Hole_pattern — Orifice operation diagram depending on the spool position.#

The spool position is determined by the formula (2):

(2)#\[\frac{\Delta P+\Delta P_{min}}{\Delta S}\cdot S=P_L-P_R\]

where:

\(\Delta P\) - set pressure drop when the spool is in the extreme position, [Pa].

\(\Delta P_{min}\) - minimum pressure drop when the spool is in the extreme position, equal to 1e-5 [Pa];

S - spool position, [m];

\(P_R, P_L\) - pressure in the right and left control ports, [Pa].

1. Properties#

Property	Default Value	Description	Units of measurement
Area port	0.001	-	m\(^2\)
Maximum area	1.0e-4	-	m\(^2\)
Leakage area	1.0e-9	-	m\(^2\)
Spool min position	0.01	-	m
Spool stroke	0.05	-	m
Discharge coefficient	0.64	-	-
Critical Reynolds number	150.0	-	-
Pressure drop set	100000.0	-	Pa
Smoothing factor	0.01	-	-

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Port C1	Input	-	-	Thermohydraulics
Port P	Input	-	-	Thermohydraulics
Port T	Input	-	-	Thermohydraulics
Port A	Output	-	-	Thermohydraulics
Port B	Output	-	-	Thermohydraulics
Port C2	Output	-	-	Thermohydraulics

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