.AixLib.Examples.Tutorial.SimpleHouse.SimpleHouse4 .AixLib.Examples.Tutorial.SimpleHouse.SimpleHouse4The wall temperature (and therefore the room temperature) is quite low. In this step a heating system is added to resolve this. It consists of a radiator, a pump and a heater. The radiator has a nominal power of 3 kW for an inlet and outlet temperature of the radiator of 60°C and 40°C, and a room air and radiative temperature of 20°C. The pump has a (nominal) mass flow rate of 0.1 kg/s. Since the heating system uses water as a heat carrier fluid, the media for the models in the heating circuit should be set to MediumWater.
The radiator contains one port for convective heat transfer and
one for radiative heat transfer. Connect both in a reasonable way.
Since the heating system uses water as a heat carrier fluid, the
media for the models should be set to MediumWater.
The Boundary_pT model needs to be used to set an
absolute pressure somewhere in the system. Otherwise the absolute
pressure in the system is undefined. Pressure difference modelling
may be disregarded in the heating circuit since the chosen pump
sets a fixed mass flow rate regardless of the pressure drop.
Set the heater input to 1, meaning that it will produce 1 times its nominal power.
The pump and the heater need a control input, which we set here
to a constant of 1. However, in the next version of this
model, we want to connect an actual controller to these models. We
can therefore introduce a Boolean constant (or a
Boolean parameter would also work), and use this to
conditionally remove the Modelica block that outputs the control
signal. When Modelica removes such a block, then all connections to
it will also be removed.
The result of the air temperature is plotted in the figure below. The temperature rises very steeply since the wall is relatively well insulated (k=0.04 W/(m*K)) and the heater is not disabled when it becomes too warm.
