Valve (MF)#

The Valve (MF) block models shut-off and control valves in a pipeline system with a multi-component medium.

Law of conservation of mass (1) :

(1)#\[\dot m_А+\dot m_В=0\]

where:

\(\dot m_A\) – mass flow rate at the input, [kg/s];

\(\dot m_В\) – mass flow rate at the outlet, [kg/s].

Law of conservation of energy (2) :

(2)#\[\phi_А + \phi_В=0\]

where:

\(\phi_А\) – energy flow at the input, [W];

\(\phi_B\) – output energy flow, [W].

Pressure drop: (3) :

(3)#\[\Delta P=(\frac{Q}{K_v})^2\]

where:

\(\Delta P\) – pressure drop across the valve, [bar];

\(Q\) – volume flow, [m\(^3\)/h];

\(K_v\) – flow capacity coefficient, [m\(^3\)/h], (4) :

(4)#\[K_v=0.865 \cdot C_v\]

where \(C_v\) is the flow capacity coefficient, [m\(^3\)/h].

The unit provides 3 modes for calculating the output pressure:

According to the outlet pressure (5):

(5)#\[P_{вых}=P_{зад}\]

where:

\(P_{out}\) – pressure at the valve outlet, [Pa];

\(P_{set}\) – pressure specified by the user as output, [Pa].

By opening percentage and \(K_v\) (6) :

(6)#\[P_{вых}=P_{вх}-(\frac{Q}{Kv_{effective}})^2\]

where:

\(P_{out}\) – pressure at the valve outlet, [bar];

\(P_{zad}\) – pressure at the valve inlet, [bar];

\(Q\) – volume flow, [m\(^3\)/h];

\(Kv_{effective}\) – effective flow coefficient, [m\(^3\)/h], (7) :

(7)#\[Kv_{effective}=Kv_{max} \cdot \frac{О}{100}\]

where:

\(Kv_{max}\) – flow coefficient calculated as the volumetric flow rate of water at \(\rho\)=1000 [kg/m\(^3\)], which passes through the valve with a pressure drop of 1 [bar];

\(О\) – percentage of opening of shut-off valves, %.

By opening percentage and \(C_v\) (8) :

(8)#\[P_{вых}=P_{вх}-(\frac{Q}{Cv_{effective}})^2\]

where:

\(P_{out}\) – pressure at the valve outlet, [bar];

\(P_{zad}\) – pressure at the valve inlet, [bar];

\(Q\) – volume flow, [m\(^3\)/h];

\(Сv_{effective}\) – effective flow coefficient, [m\(^3\)/h], (9) :

(9)#\[Сv_{effective}=Сv_{max} \cdot \frac{О}{100}\]

where:

\(Сv_{max}\) – flow capacity coefficient, calculated as the volumetric flow rate of water at \(\rho\)=1000 [kg/m\(^3\)], which passes through the valve with a pressure drop of 1 [bar];

\(О\) – percentage of opening of shut-off valves, %.

1. Properties#

Property	Default Value	Description	Units of measurement
Valve calculation: By outlet pressure; By valve opening and K\(_v\); By valve opening and C\(_v\)	By outlet pressure	-	-
Outlet pressure	200000.0	Available, when `Valve calculation` - `Outlet pressure`	Pa
Percentage of valve opening	100.0	Available, when `Valve calculation` - `By valve opening and` K\(_v\) or `By valve opening and` C\(_v\)	%
Flow factor C\(_v\)	280.0	Available, when `Valve calculation` - `By valve opening and` C\(_v\)	м\(^3\)/ч
Flow factor K\(_v\)	280.0	Available, when `Valve calculation` - `By valve opening and` K\(_v\)	м\(^3\)/ч

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Input	Input	-	-	Multicomponent fluid
Output	Output	-	-	Multicomponent fluid

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