ShowerHeater_abg.tex

MTT command:

mtt ShowerHeater abg tex

Figure 6.1: System ShowerHeater: acausal bond graph

The acausal bond graph of system ShowerHeater is displayed in Figure 6.1 (on page ) and its label file is listed in Section 6.1.1 (on page ). The subsystems are listed in Section 6.1.2 (on page ).

ShowerHeater is a very elementary model of an electric heater suitable for a shower. It illustates the use of bond graph components which are internally pseudo, but externally true bond graphs (temperature/entropy flow).

There are three main components:

1. p1 and p2 - a Pipe component (see Section 6.1.6 (on page )). It is assumed that the pipes have zero flow resistance and thus do not generate heat via flow resistance.
2. t1 - a tank Tank component.
3. Heater - a resistive heater modelled by the thermodynamic R component RS.

Other components could be added to represent thermal conduction and thermal capacities.

The components In and Out provide the inlet and outlet conditions.

The three inputs are

$u_1$

The flow rate

$u_2$

The inlet temperature

$u_3$

The voltage across the heating element.

The single output is

$y_1$

The outflow temperature

and the state is

$x_1$

The heat contained in the tank.