It adds equations for the heat rates Pp1 and
Pp2 and the temperatures
Tp1 and
Tp2 at the connecting ports
p1 and
p2 of the component, and defines the following relation between the heat rate
P and the temperature difference
ΔT:
where R (SI unit: K/W) is the total thermal resistance, accounting for the relevant heat transfer processes present in the heat pipe. It may be defined either directly or as the sum of the resistances related to conduction through the solid wall and porous wick of the heat pipe, depending on the available data for the thermal and geometric properties.
Note that ΔT =Tcondenser -Tevaporator and is meant to be negative in the classical operating mode of the heat pipe. The heat rate
P is set to 0 when this condition does not hold.
See Theory for the Heat Pipe Component for more details on the underlying theory.
By default the Temperature is
User defined and the average of the two port temperatures,
Tave = 0.5*(Tp1+Tp2), is set.
Enter a Component name for the heat pipe. The prefix is
HP.
Set the two Node names for the nodes connected by the heat pipe. Note that the ports
p1 and
p2 correspond respectively to the evaporator and condenser sides of the heat pipe.
Select an option from the Model list for the expression of the total thermal resistance
R:
When Input quantity is set to
Thermal resistances, enter values or expressions for the
Thermal resistance, evaporator wall,
Rwall,e, the
Thermal resistance, evaporator wick,
Rwick,e, the
Thermal resistance, condenser wick,
Rwick,c, and the
Thermal resistance, condenser wall,
Rwall,c.
Alternatively, set Input quantity to
Configuration and thermal properties to calculate the thermal resistances from the geometric dimensions and thermal properties of the wick and wall of the heat pipe. This option is available for a flat or cylindrical heat pipe. Further settings display underneath to define the geometric configuration. You can refer to the
Sketch section to get an illustration of the configuration.
The thermal conductivity ks of the wall should be set in this section when
Input quantity is set to
Configuration and thermal properties in the
Component Parameters section.
Select any material from the Material list to define the
Thermal conductivity k From material. Alternatively, choose among
Copper and
Aluminum for a predefined material. For
User defined enter a value or expression.
The thermal conductivity keff of the wick should be set in this section when
Input quantity is set to
Configuration and thermal properties in the
Component Parameters section.
The wick is a porous medium. When Input quantity is set to
Structure model, its effective thermal conductivity is expressed as a function of its porosity and the thermal conductivities of the immobile solid and the liquid parts.
Select any material from the Material list to define the
Thermal conductivity, liquid kl From material. Alternatively, choose among
Water and
Mercury for a predefined material. For
User defined enter a value or expression.
Select any material from the Material list to define the
Thermal conductivity, immobile kw From material. Alternatively, choose among
Copper and
Aluminum for a predefined material. For
User defined enter a value or expression.
Then, set a value or expression for the Porosity,
ε, and select an option from the
Structure list to calculate the effective conductivity. See
Theory for the Heat Pipe Component for details.
Finally, select the Specify operating maximum power check box to curb the heat pipe when the operating maximum power
Pmax is known. Set a value or expression for
Pmax.
Set user defined values or expressions for the Initial temperature at node 1,
T1,init, and the
Initial temperature at node 2,
T2,init, to be used at initialization, in particular to evaluate the material properties of the heat pipe.
Select appropriate options in the Add the following to default results in order to include the following global variables (space-independent) in the default plots:
