A first-principles simulation model for the start-up and cycling transients of household refrigerators

A first-principles model for simulating the transient behavior of household refrigerators is presented in this study. The model was employed to simulate a typical frost-free 440-l top-mount refrigerator, in which the compressor is on–off controlled by the freezer temperature, while a thermo-mechanical damper is used to set the fresh-food compartment temperature. Innovative modeling approaches were introduced for each of the refrigerator components: heat exchangers (condenser and evaporator), non-adiabatic capillary tube, reciprocating compressor, and refrigerated compartments. Numerical predictions were compared to experimental data showing a reasonable level of agreement for the whole range of operating conditions, including the start-up and cycling regimes. The system energy consumption was found to be within ±10% agreement with the experimental data, while the air temperatures of the compartments were predicted with a maximum deviation of ±1 °C.