A novel ammonia-water combined power and refrigeration cycle with two different cooling temperature levels

A new ammonia-water cogeneration system is proposed to produce power and refrigeration outputs simultaneously, which combines Kalina power cycle and ejector refrigeration cycle. This cycle has two evaporators that can produce refrigeration output in two different temperature levels and capacities, in which the first evaporator pressure may be selected independently. This capability of the proposed cycle increases the number of possible applications while the complexity of the system doesn't vary much. Adjustable power to cooling ratio is another feature of this novel cycle, by changing the reboiler reflux ratio different power to cooling ratios can be reached. The cycle performance was evaluated by exergy efficiency, net power and refrigeration outputs. The effect of key parameters such as turbine inlet pressure, heat source temperature, condenser temperature, evaporation temperature and basic working solution ammonia concentration on the cycle performance have been investigated. It is found that the cycle's thermal performance is acceptable with exergy efficiency of 38.97%, effective exergy efficiency of 42.75% and thermal efficiency of 19% for the base case study.