Performance analysis of compressor-assisted two-stage triple effect absorption refrigeration cycle for power and cooling

Abstract

Ammonia-water absorption and power cycles offer a viable option for the effective use of low and medium temperature heat sources for sub-zero cooling and power generation. The proposed system is a compressor assisted two-stage triple effect absorption cycle for power and cooling. This system comprises of power sub-system and absorption-compressor sub-system and both systems utilize ammonia-water mixture as the working fluid. The power generated by the cycle is used for the compression required to enhance the performance of the cycle. The mathematical model of the proposed system is analyzed using first and second law of thermodynamics. The engineering equation solver (EES) software is employed to analyze the model. Thermodynamic performance of the combined cycle was evaluated based on the compression ratio and the heat source inlet temperature. The pressure ratio (Prcom) of the integrated compressor is varied between 1.0 and 1.6 to observe the effect on the operation, output, and performance of the system. The simulation result shows that the heat source inlet temperature can be reduced by 50 °C compared to the traditional two-stage triple effect absorption system. The effective energy and exergy efficiencies are 17% and 76% respectively while the cooling load was 165.4 kW. The results also showed that asorber1 and absorber 2 have the highest rate of exergy destruction of 30.91% and 37.32% followed by condenser 1 with 16.3% and solution heat exchanger 2 with 7.89%. It is observed that the proposed system performs better in comparison to its counterparts operated at medium temperature heat sources.