Assessment of an ammonia-water power/cooling cogeneration system with adjustable solution concentration

Binary working fluid has been widely used in mid/low-temperature sensible waste heat utilization. This study proposes an ammonia-water power/cooling cogeneration system with adjustable solution concentration. The turbine exhaust heat and the ammonia contained in the turbine exhaust vapor are recovered by the refrigeration subsystem. The strong solution concentration at the absorber outlet can be adjusted to adapt to different operating conditions. The energy efficiency and exergy efficiency of the cogeneration system in the base case are 40.6% and 36.4%, respectively. Analysis of the effect of strong solution concentration on the system performance reveals that the system performs better at higher strong solution concentration. The performance comparison of the cogeneration systems with fixed and with adjustable solution concentration at different evaporation and cooling water temperatures validates the favorable effect of the solution concentration adjustment. This study can serve as a reference for process optimization of the binary working fluid-based power/cooling cogeneration system that uses mid/low-temperature waste heat. (C) 2013 Elsevier Ltd. All rights reserved.