Numerical analysis of a novel household refrigerator with controllable loop thermosyphons

Efficiency improvement of household refrigerators exerts extensive influences on the reduction in residential energy consumption and alleviation of environmental pollution. Controllable loop thermosyphons (CLTs) are low-cost, high-precision heat transfer control devices that can be potentially applied in refrigerators as crucial energy saving and temperature management components. A novel refrigerator with CLTs is proposed in this study. The evaporator in fresh food compartment is removed, the cold loss of the topside freezer is partly reused by the CLTs to cool the fresh food compartment in intermittent mode, and the overall cold loss of the refrigerator is efficiently reduced. The energy saving behaviour of the refrigerator is numerically studied based on tested temperature boundary conditions. The energy saving mechanism is comparatively analyzed, and the impacts of the operating condition, installation position of the CLTs, and ambient temperature are investigated. The energy saving ratio of the novel refrigerator increases from 12.9% to 19.5% when the ambient temperature rises from 17.0 °C to 31.0 °C, the operating condition varies from 1 to 4, and the locations of CLTs from the inner wall of the freezer are changed from 2.1 to 4.9 mm. Results preliminarily prove the energy saving capability of the novel refrigerator.