Development of a New Solar-Assisted Refrigeration Pipe for Potential Permafrost Protection

Abstract

This study proposes a new solar-assisted refrigeration method to protect the permafrost underlying an embankment from degradation. It was initially revealed that the mediocre performance of the current permafrost protection systems was due to a lack of energy needed to make these systems more efficient. In this study, heat-driven adsorption refrigeration technology was considered to satisfy the real-time performance and effectiveness of permafrost protection. A prototype of the solar photothermal adsorption refrigeration pipe was designed and manufactured, and its practical performance was experimentally investigated. The test results indicate that the prototype demonstrates good performance corresponding to the lowest refrigerating temperature of −2.9°C, with an average of −1.5°C in warm seasons. The prototype can also maintain stable output with daily cooling capacity and COP values approaching 81.23 kJ and 0.067, respectively, which can be improved by using a larger apparatus size in practical application. The authors thus conclude that the new structure may be a potential candidate for the thermal maintenance of subgrade engineering.