Calibration Strategies And Limitations Of Cycle Simulations Representing Complex Domestic Cooling Devices

Transient cycle simulations are commonly said to be a tool for improving and understanding the operating behavior of cooling cycles. Assuming a properly working simulation tool, simple cycle configurations which are driven by On/Off-controlled compressors can meanwhile be modelled with relatively high effort. Given the growing complexity of today's modern refrigeration appliances – in particular cooling/freezing combinations – it is getting more and more challenging to represent these in a satisfactory manner. Fans for ventilation, variable speed drives and switchable capillary tubes are in interaction and follow a sensor-controlled, prescribed logic. The focus of this paper lies on the simulation of a particular real world appliance, which features all before-mentioned actuators. The simulation tool comprises component models beyond state of the art which have been validated both independently and in a simple cycle configuration. The attempt of modelling the cooling/freezing combination leads to new knowledge concerning the approach of calibrating the model. Measurement data (temperature, pressure, electric power, state variables) is available and used as reference. It can be shown, that it is possible to shape the model to follow the order of switching commands of the real appliance. Effects like heat conduction from walls to the sensors, delay caused by the thermal inertia of the sensors or temperature stratification pose the main obstacle on the way to obtain a comparable energy consumption.