This model simulates the effect of opening and closing the refrigerator and freezer compartment doors in a household refrigerator. The flow of heat and the circulation of air, both within the refrigerator and between the refrigerator and the external environment, are modeled with components from the HeatTransfer library and the FluidHeatFlow library.

The other two models in this example are HotFood and NearEmpty, which compare the effects of adding hot food to a normally loaded and a near-empty refrigerator, respectively.

Simulation

The model simulates the effect of opening and closing compartment doors according to a prespecified schedule. To see or modify the schedule, select the fridgeDoor or freezerDoor components in the DoorOpening model. The schedule is specified in the Parameters view at the bottom of Model Center.

To simulate the model, click the Simulate button:

By default, the model is simulated over a period of 8000 seconds.

Visualization

After simulating the model, a Model plot will be displayed, showing the temperature of the air and food in the freezer compartment. An annotated version of the freezer compartment plot looks like this

You can see that there are several discontinuities in the rate of temperature change corresponding to predetermined events such as compartment doors opening and closing, and dynamic events such as thermostats being triggered.

Visualize Events

You can visualize the various discrete events by clicking on the Model plot name Events

The resulting plot looks like this, depending on your choice of styles:

Other Scenarios

Try simulating the other two models in this example, HotFood and NearEmpty, to compare the effects of adding hot food to a normally loaded and near-empty refrigerator, respectively.