This example shows how to use a Modelica model to solve for some
unknown parameters, given some desired system output (please look
at the Modelica textual code). In this case, the nominal heat
transfer coefficient Plant.Boiler.gamma_nom is
computed in order to obtain an initial value of the gas outlet
temperature equal to 130 degrees Celsius. This can be used to match
the model to known design data. Note that steady-state initial
conditions are required to make the computation meaningful.
This is performed by defining a gamma_unknown
parameter at the top level, with a fixed = false
attribute (meaning that its value is a unknown) and with a
start = 150 attribute to provide a reasonable initial
guess for the solver. This parameter is then used to override the
value of Plant.Boiler.gamma_nom. In order to obtain a
closed initialization problem, a corresponding initial equation to
set the desired value of Plant.GasOut.T is added.
The transient starts at steady state, with the desired values of the heat transfer coefficient and gas outlet temperature. At time t = 100 s, the water valve is closed by 10%. At time t = 200 s, the gas flow rate is increased by 10%.