Theoretical and experimental study of improved cycle for large temperature lifts application in ammonia water absorption system.

In ammonia water absorption chillers, the rectification heat is dissipated to the surroundings. An improved cycle with utilization of rectification heat is proposed when the chiller is operated either at large temperature lifts or low hot source temperature. This cycle combines the solution recirculation and heat integration of rectifier. The rectification heat recovery is implemented through splitting the strong solution leaving the absorber in two branches. One branch flows through the solution heat exchanger while the other branch flows through the rectifier. In this paper, the selection of split ratio is investigated by varying the operating condition. A prototype is built and tested for experimental verification. The relation between system performance and temperature lift shows a close tendency with the theoretical results.