Second law-based thermodynamic analysis of ammonia/sodium thiocyanate absorption system

In this study, the first and second law of thermodynamics are used to analyze the performance of a novel absorption system for cooling and heating applications. The active component of the sorbent used in this study is sodium thiocyanate (NaSCN). Ammonia (NH3) is chosen as sorptive. A mathematic model based on exergy analysis is introduced to analyze the system performance. Enthalpy, entropy, temperature, mass flow rate and exergy loss of each component and the total exergy loss of the system are evaluated. Furthermore, the coefficient of performance (COP) and exergetic efficiency of the absorption system for cooling and heating processes are calculated from the thermodynamic properties of the working fluids under different operating conditions. The results show that the COP of cooling and heating increases with the heat source temperature and decreases with the cooling water inlet temperature, but the system exergetic efficiency does not show the same trends for both cooling and heating applications. The simulation results can be used for the thermodynamic optimization of the current system.