Tank (TL)#

The Tank (TL) block simulates a tank with a variable volume of fluids. The pressure above the fluid surface can be set to the atmospheric one (opened tank) or user pressure using the appropriate block properties.

The user can select from 1 to 6 input ports through which the coolant flows.

The volume of coolant in the tank can exchange heat with the heat network, for example, heat exchange with the environment through the thermal port of the unit.

The thermal resistance between the thermal port and the internal part of the tank is negligible and the temperature inside is equal to the temperature in the thermal port.

Important

When the level in the tank drops below the level of the cut-in, the calculation is completed with an error.

1. Mass balance

Mass conservation law (1) :

(1)#\[\dot m_1+\dot m_2+\dot m_3+\dot m_4+\dot m_5+\dot m_6=\dot M\]

where:

\(\dot M\) - change of fluid mass in the tank, [kg/s];

\(\dot m_1, \dot m_2, \dot m_3, \dot m_4, \dot m_5, \dot m_6\) - mass flow rates through input ports, [kg/s].

2. Energy balance

Energy conservation law (2) :

(2)#\[\phi_1+\phi_2+\phi_3+\phi_4+\phi_5+\phi_6+Q-(\dot m_1+\dot m_2+\dot m_3+\dot m_4+\dot m_5+\dot m_6)\cdot h= M\cdot C_p \cdot \dot T\]

where:

h - enthalpy of the medium in the tank, [J/kg];

\(C_p\) - specific isobaric heat capacity, [J/(kg\(\cdot\)K)];

Q - heat flow through the heat port, [W];

\(\phi_1, \phi_2, \phi_3, \phi_4, \phi_5, \phi_6\) - energy flows through input ports, [W].

3. Pulse balance (3):

(3)#\[p_i+p_{дин}=p_б+\rho \cdot g \cdot (h-h_i)\]

where:

\(p_i\) - pressure of the i-th input port, [Pa];

\(p_{dyn}\) - dynamic pressure, [Pa];

\(p_б\) - pressure above the fluid surface, [Pa];

\( ho\) - fluid density, [kg/m\(^3\)];

g - gravity factor, [m/s\(^2\)];

h - fluid level in the tank, [m];

h\(_i\) - cut-in level, [m].

Dynamic pressure (4) :

(4)#\[\begin{split}p_{дин} = \begin{cases} 0, \dot{m_i}\ge 0 \\ \frac{\dot{m_i}^2}{2\cdot \rho \cdot S_i^2} ,\dot{m_i}\lt 0 \end{cases}\end{split}\]

4. Medium volume in the tank

The medium volume in the tank is calculated based on the mass and density at each calculation step according to the following formula (5) :

(5)#\[V=M/\rho\]

where:

M - medium mass in the tank, [kg];

V - medium volume, [м\(^3\)].

1. Properties#

Property	Default Value	Description	Units of measurement
Number of input ports: 1; 2; 3; 4; 5; 6	1	-	-
Gauge pressure above liquid level specification/a>: Atmospheric pressure; Specified pressure	Atmospheric Pressure	-	-
Gauge pressure above liquid level, available when `Gauge pressure above liquid level specification` - `Specified pressure`	0.0	-	MPa
Tank cross-section area	1.0	-	m\(^2\)
Inlet height	0.1	-	m
Inlet cross-sectional area	0.01	-	m\(^2\)
Gravitational acceleration	9.81	-	m/s\(^2\)
Initial tank liquid level	3.0	-	m
Initial tank liquid temperature	20.0	-	℃

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Input	Input	From 1 to 6, depending on the choice of property - `Number of input ports`	-	Thermohydraulics
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