Feasibility study on ammonia water absorption refrigeration cycle without distillation column.

• An ammonia-water absorption refrigerator without distillation column is proposed. • Such cycle can be applied under a very small temperature lift applications. • COP of such cycle is enhanced by 42.6% through heat exchanger network analysis. • The improvement in COP is the combination of different internal heat recoveries. • The payback period of the cycle with optimum COP is 4.28 years. The water content in the refrigerant may undermine the cooling effect in ammonia water absorption refrigeration systems. Distillation column is normally implemented. The use of distillation columns, however, may increase system complexity, especially in practical operation. In fact, the distillation column can be eliminated under particular operating conditions. This paper presented an ammonia water absorption refrigeration cycle without distillation column, which is replaced by two separators and one heater. The resulting vapor is nearly pure with an ammonia mass fraction of 0.998. Heat exchanger network analysis is carried out for searching all the potential heating-saving possibilities. The thermal performance was improved by the combination of solution recirculation and absorption heat recovery, and the results indicated that the thermal performance has been increased by 42.6% than that of the basic cycle at certain working condition. The proposed cycle has limited ranges of working conditions operated under small temperature lifts,and the payback period is 4.28years. [Display omitted] [ABSTRACT FROM AUTHOR]