The use of phase change materials in domestic refrigerator applications

This paper presents a study on the application of PCMs to domestic refrigerators. It is the result of a 4 year Industrial Case Award PhD supported by the EPSRC and Adande Refrigeration. The research focused on the design and operation of the thermal storage refrigerator aiming to improve the appliance efficiency, temperature stability and energetic autonomy. To achieve the project goals first the performance of a conventional refrigerator was analysed, in particular the size and efficiency of the compressor and its impact on the overall system performance. The operation of the thermal storage refrigerator was investigated by estimating the PCM melting and freezing time. A computational fluid dynamics (CFD) model was used to predict the airflow and temperature distribution within the thermal storage refrigerator. Several design options were simulated to identify the most effective PCM configuration (horizontal or vertical) and phase change temperature. A test rig was designed and constructed to validate experimentally the theoretical models which predicted the performance of the refrigerator with a horizontal PCM. The experimental results obtained for a prototype refrigerator will be presented and discussed.