A co-simulation method of refrigerator system and temperature field

There are mainly two approaches to simulating refrigeration equipment such as refrigerators. The refrigeration system model can reasonably simulate the transient cyclic performance of the refrigeration system, while the computational fluid dynamics (CFD) model focuses more on temperature and velocity fields inside cabinets. To bridge the gap between the two modeling approaches, this study proposes a novel co-simulation method, namely the reduced-order temperature field model (ROM). Two special parameters, time constant and temperature deviation, are extracted from the full-order CFD results to characterize the temperature transients of user-specified locations. Then the ROM extends the lumped cabinet temperature into temperature distributions through the aforementioned two parameters in system simulation. Thus, temperature field transients can be approximately presented in the dynamic system simulation. System pressures, power, and temperature distributions in different compartments were measured to validate the ROM. The majority of time-average temperature errors in the refrigeration compartment are within 1.0 °C in the pull-down stage and 1.1 °C in the on–off stage. The majority of time-average temperature errors in the freezer compartment are less than 2.5 °C in the pull-down stage of the lower layer and 3.0 °C in the upper layer, while all temperature errors are within 1.5 °C in the on–off stage.