摘要

In a water-ammonia absorption refrigeration system, the rectification heat is dissipated to the surroundings without recovering in traditional single-effect cycle. An improved cycle is proposed for the utilization of rectification heat when the chiller is operated under a large temperature lift or low heat source temperature when GAX (Generator-Absorber heat eXchange) effect is not available. This cycle combines the solution recirculation and heat integration of rectifier to improve the COP. The rectification heat recovery is implemented through separating the strong solution leaving the absorber. One branch flows through the solution heat exchanger while the other branch flows through the rectifier. The result shows 24% increase in COP compared with traditional single-effect cycle under certain working conditions. In this paper, the selection of split ratio is investigated by varying the working condition. The effect of solution recirculation and rectification heat recovery is comparatively studied through case studies. In general, the most operations in traditional single-effect cycle can be replaced by the improved cycle. A graphic aid for the assistance of the choosing suitable cycle is presented as well.