Design and experimental study of a solar compression refrigeration apparatus (SCRA) for embankment engineering in permafrost regions

The current active cooling structures, which were successfully adopted in the construction of the Qinghai–Tibet Railway, sometimes cannot maintain the long–time foundation stability in warm permafrost regions. The objective of this study is to present and examine a novel solar assisted compression refrigeration system. A special refrigeration apparatus was designed and manufactured, and its practical performance was experimentally investigated. The test results indicated that the new structure demonstrates excellent refrigerating performance corresponding to negative temperatures in warm seasons, and the temperature can be automatically controlled at −5, −10 and −15 °C; in addition, the new structure has a low energy consumption with the corresponding coefficient of performance (COP) of 6.68, 4.91, 3.45. The study provides reference and guidance for railway design and construction in permafrost regions, such as for the Sichuan–Tibet Railway.