Constant Volume Chamber (TL)#

The Constant Volume Chamber (TL) block simulates the accumulation of mass and energy in a chamber containing fixed volume of coolant.

The user can specify from 1 to 4 input ports through which the coolant flows.

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

The medium enters the chamber the pressure upstream the inlet exceeds pressure in the chamber and flows out when pressure drop is reversed.

It is assumed that the flow resistance between the inlet and the chamber internal part is negligible. Thus, pressure inside the chamber is equal to pressure at the inlet ports.

Similarly, thermal resistance between the thermal port and chamber internal part is negligible and temperature inside is equal to temperature in the thermal port.

Mass flow rate calculation

Law of conservation of mass (1):

(1)#\[\dot{m_1}+\dot{m_2}+\dot{m_3}+\dot{m_4}=(\frac{1}{\beta}\cdot\frac{dp}{dt}-\alpha \cdot \frac{dT}{dt})\cdot \rho \cdot V\]

where:

p - medium pressure in the chamber, [Pa];

T - medium temperature in the chamber, [℃];

\(\alpha\) - isobaric thermal expansion coefficient, [1/К];

\(\beta\) - fluid bulk module, [Pa];

\(\rho\) - medium density in the chamber, [kg/m\(^3\)];

V - chamber volume, [m\(^3\)];

\(\dot{m_1}\), \(\dot{m_2}\), \(\dot{m_3}\), \(\dot{m_4}\) - Mass flow rate through input ports, [kg/s].

Energy balance

Law of conservation of energy (2) :

(2)#\[Ф_1+Ф_2+Ф_3+Ф_4+Q=((\frac{h}{\beta}-\frac{T\cdot \alpha}{\rho})\cdot\frac{dp}{dt}+(c_p-h\cdot\alpha)\cdot\frac{dT}{dt})\cdot \rho \cdot V\]

where:

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

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

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

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

Momentum balance

p=p\(_1\)=p\(_2\)=p\(_3\)=p\(_4\)

where p\(_1\), p\(_2\), p\(_3\), p\(_4\) - pressure of input ports, [Pa].

1. Properties#

Property	Default value	Description	Units of measurement
Number of ports: 1; 2; 3; 4	1	-	-
Chamber volume	2.0	-	m\(^3\)
Port 1 cross-sectional area	0.01	-	m\(^2\)
Port 2 cross-sectional area	0.01, available when selecting `Number of ports` - `2`, `3` or `4`	-	m\(^2\)
Port 3 cross-sectional area	0.01, available when selecting `Number of ports` - `3` or `4`	-	m\(^2\)
Port 4 cross-sectional area	0.01, available when selecting `Number of ports` - `4`	-	m\(^2\)
Initial temperature of liquid volume	20.0	-	deg
Initial gauge pressure of liquid volume	0.0	-	Pa

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Input	Input	-	The number of `Thermohydraulics` input ports corresponds to the selected value of the `Number of ports` property.	Thermal Hydraulics
Thermal port	Input	-	-	Heat exchange

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