Saturated fluid chamber (TPF)#

block — Block appearance in REPEAT VISION#

The Saturated fluid chamber (TPF) is a chamber with a constant volume. The chamber volume is divided into the volume of liquid at saturation and the volume of vapor at saturation.

Input port 1 is connected to a volume of vapor, and input port 2 to a volume of liquid. Thus, the medium leaving input port 1 is always saturated vapor, and from port 2, it is saturated liquid. The input medium can be in any state.

Law of Conservation of Mass (1) :

(1)#\[\dot m_A + \dot m_B = \frac{dM}{dt}\]

where:

\(M\) – mass of the medium in the chamber, [kg];

\(\dot m_A\) – mass flow rate at input 1, [kg/s];

\(\dot m_B\) – mass flow rate at output 2, [kg/s].

Law of conservation of energy (2) :

(2)#\[\phi_A + \phi_B + Q=(\dot m_A + \dot m_B)\cdot u_K + M \cdot \frac{du_K}{dt}\]

where:

\(\phi_A\) - energy flow at the input 1, [W];

\(\phi_B\) - energy flow at the output 2, [W].

\(Q\) – heat flow through the heat port, [W];

\(u_K\) – specific internal energy of the environment in the chamber, [J/kg].

Impulse balance

It is assumed that the pressure drop between the input ports and the internal volume of the chamber is negligible, so (3) :

(3)#\[p_1=p_2=p_K\]

\(p_1\) – pressure at input 1, [Pa];

\(p_2\) – pressure at input 2, [Pa];

\(p_K\) – pressure in the chamber, [Pa].

Mass of medium in chamber (4) :

(4)#\[M=M_п+M_ж\]

where:

\(M_п\) – mass of saturated steam in the chamber, [kg];(5)

\(M_ж\) is the mass of saturated liquid in the chamber, [kg].(6)

(5)#\[M_п=(1-L) \cdot \frac{V}{v_п}\]

where:

\(L\) – volume fraction of liquid in the chamber;

\(V\) – chamber volume, m\(^3\);

\(v_п\) – specific volume of saturated steam, [m\(^3\)/kg].

(6)#\[M_ж=L \cdot \frac{V}{v_ж}\]

where \(v_ж\) is the specific volume of saturated liquid, [m\(^3\)/kg].

Heat port temperature

It is assumed that the thermal resistance between the thermal port and the internal volume of the chamber is negligible, thus (7) :

(7)#\[T_П=T_K\]

where:

\(T_П\) – temperature in the heating port, [\(^о\)C];

\(T_K\) - temperature of the environment in the chamber, [\(^о\)C];

Note

The block contains the properties: Minimum liquid volume fraction and Maximum liquid volume fraction. These properties regulate the minimum and maximum permissible level of the liquid fraction; if the maximum is exceeded or the minimum level falls below, the calculation will end with a corresponding error in the log:

The minimum volume fraction of the liquid phase cannot be less than 0;
The maximum volume fraction of the liquid phase cannot be greater than 1.

1. Properties#

Property	Default Value	Description	Units of measurement
Chamber volume	1.0	-	m\(^3\)
Port 1 cross-sectional area	0.01	-	m\(^2\)
Port 2 cross-sectional area	0.01	-	m\(^2\)
Initial gauge saturation chamber pressure	0	-	Pa
Initial liquid volume fraction	0.5	-	-
Minimum liquid volume fraction	0.01	-	-
Maximum liquid volume fraction	0.99	-	-

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Input 1	Input	-	-	Two-phase fluid
Input 2	Input	-	-	Two-phase fluid
Heat port	Input	-	-	Heat exchange

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