.TransiEnt.Components.Heat.ThermalInsulation.Basics.Conduction_L4

Information

1. Purpose of model

This is a model for transport of heat without storing it; see also: ThermalResistor. It may be used for complicated geometries where the thermal conductance G (= inverse of thermal resistance) is determined by measurements and is assumed to be constant over the range of operations.

2. Level of detail, physical effects considered, and physical insight

If the component consists mainly of one type of material and a regular geometry, it may be calculated, e.g., with one of the following equations:

• Conductance for a box geometry under the assumption that heat flows along the box length:

G = k*A/L

k: Thermal conductivity (material constant)

A: Area of box

L: Length of box

• Conductance for a cylindrical geometry under the assumption that heat flows from the inside to the outside radius of the cylinder:

G = 2*pi*k*L/log(r_out/r_in)

pi : Modelica.Constants.pi

k : Thermal conductivity (material constant)

L : Length of cylinder

log : Modelica.Math.log;

r_out: Outer radius of cylinder

r_in : Inner radius of cylinder

Typical values for k at 20 degC in W/(m.K):

aluminium 220

concrete 1

copper 384

iron 74

silver 407

steel 45 .. 15 (V2A)

wood 0.1 ... 0.2

3. Limits of validity

(none)

4. Interfaces

(none)

5. Nomenclature

(no elements)

6. Governing Equations

(no equations)

7. Remarks for Usage

(none)

8. Validation

(no validation or testing necessary)

9. References

(none)

10. Version History

Model created by Michael von der Heyde (heyde@tuhh.de) for the Research Project "Future Energy Solution" (FES), 2020

Contents

Name	Description
Material	Material of the cylinder