Utilization of waste heat from separation process of Ulubelu's geothermal power plant by implementing an Absorption Refrigeration System (ARS) to improve plant performance

Utilization of geothermal energy for water-dominated reservoir usually involves a separation process that turns geothermal fluid mixtures into pure steam and brine water. This process also occurred on Ulubelu's geothermal power plant (GPP). As waste energy from the power generation process, the remaining heat energy in brine water is still high enough to run an absorption refrigeration system (ARS). This study proposed an integrated power generation and absorption system that operate side by side for a further cooling process. ARS will be employed to produce a lower temperature of cooling water from the GPP's cooling tower and then pass it to GPP's condenser. The lower temperature of cooling water will affect steam condensation process and the vacuum pressure of condenser, moreover, increase power production and exergy efficiency of Ulubelu's GPP. The improvement of exergy efficiency & production capacity will be observed along with the rise of the investment cost as form as the annual cost of the ARS. A Multi-objective optimization using genetic algorithm will be conducted to minimize exergy efficiency and the annual cost of ARS. The optimization will be conducted using MATLAB along with EES for work fluid properties database. The temperature of generator, absorber, condenser, and evaporator of ARS are used as decision variables. Finally, the effect of integrated system and optimum value for each decision variables are presented in this study.