WOLFRAM SYSTEM MODELER

HotFood

Model simulating the effect of adding hot food to refrigerator

Diagram

Wolfram Language

In[1]:=
SystemModel["IndustryExamples.ConsumerProducts.Refrigerator.HotFood"]
Out[1]:=

Information

This model simulates the effect of adding hot food to 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.

This model should be compared with the NearEmpty model, which simulates the addition of hot food to a near-empty refrigerator.

The other model in this example is DoorOpening, which simulates the effects of opening and closing the compartment doors.

Simulation

The model simulates the effect of a piece of hot food added at t=0 seconds to a refrigerator already normally loaded with both fresh and frozen food.

To simulate the model, click the Simulate button: simulate

By default, the model is simulated over a period of 7200 seconds.

Visualization

After simulating the model, look at the displayed plot of the food and air temperatures in the refrigerator compartment. The plot looks like this:

You can see that the fresh food temperature increases by about 2 K, which is within acceptable limits.

By simulating the NearEmpty model, you can see the effect of adding hot food to a near-empty refrigerator instead of a normally loaded one:

You can see that, in the near-empty refrigerator, the fresh food temperature increases by about 7 K, outside acceptable limits. The low thermal mass of the near-empty refrigerator also leads to excessively frequent thermostat switching, visible after t=5500 seconds.

Other Scenario

Try simulating the other model in this example, DoorOpening, to explore the effects of opening and closing the refrigerator and freezer compartment doors.

Parameters (3)

initialTemperatureFrozenFood

Value: 257.15

Type: Temperature (K)

Description: Initial temperature of frozen food

initialTemperatureHotFood

Value: 323.15

Type: Temperature (K)

Description: Initial temperature of hot food

initialTemperatureFreshFood

Value: 277.15

Type: Temperature (K)

Description: Initial temperature of fresh food

Components (11)

outerCase

Type: OuterCase

Description: Household refrigerator case and insulation

frozenFood

Type: ConvectionCooledFood

Description: Food cooled by air

freshFood

Type: ConvectionCooledFood

Description: Food cooled by air

heatPump

Type: Cooling

Description: Thermostat-controlled cooling

ambient

Type: FixedTemperature

Description: Fixed temperature boundary condition in degree Celsius

freezerCompartment

Type: Pipe

Description: Pipe with optional heat exchange

fridgeCompartment

Type: Pipe

Description: Pipe with optional heat exchange

airCirculation

Type: AirCirculation

Description: Thermostat-controlled air circulation between compartments

freezerDoor

Type: CompartmentDoor

Description: Refrigerator or freezer compartment door

fridgeDoor

Type: CompartmentDoor

Description: Refrigerator or freezer compartment door

hotFood

Type: ConvectionCooledFood

Description: Food cooled by air