Thermodynamic and thermoeconomic analysis of the absorption heat transformer, organic Rankine cycle, and reverse osmosis desalination combined system

In this study, the thermodynamic and thermoeconomic analysis of an Absorption Heat Transformer (AHT), Organic Rankine Cycle (ORC) and Reverse Osmosis (RO) desalination combined system was performed. The performance of the system was examined with the objective of generating electricity and fresh water from low temperature heat sources. All analyses are carried out based on the thermodynamic and thermoeconomic laws by programming in the EES software. The results have shown that the AHT with increase temperature to 105°C, is produced 494.7 kW thermal energy in absorber, having the Coefficient of Performance (COP) of 0.4372. By applying the AHT produced thermal energy; it is possible to produce 63.15 kW of electricity in the ORC. By using this amount of electricity in the reverse osmosis system, 216.2 m3/day of freshwater are produced where the cost of this amount of water produced achieved 2.374 $/m3. Also, in thermoeconomic analysis, the unit cost of the exergy for all points of the system and the unit cost of the electricity and fresh water were calculated. The levelized cost of electricity at different heat rates was determined, according to the results, the levelized cost of electricity is reduced when the heat rate increases. Also the effects of interest and inflation rate changes on the unit cost of the fresh water were studied.