Exergoeconomic analysis and optimization of a combined double flash – binary cycle for Ulubelu geothermal power plant in Indonesia

Abstract

Abstract. In this paper, the combination of double-flash and binary cycles for Ulubelu geothermal power plant is proposed and optimized by using the Matlab software. This proposed system uses real data and properties of brine exploited from the Ulubelu geothermal well in Indonesia and four working fluid candidates, namely n-Pentane, R141b, R123 and R245fa are used in binary cycles. Optimization using a multi-objective genetic algorithm with an exergoenomic approach is applied to find out the proposed system performance from both thermodynamic and economic point of view. In the optimization procedure, the exergy efficiency and total specific cost of output power become objective functions while the first flash pressure, second flash pressure and Organic Rankine Cycle (ORC) turbine inlet temperature are selected as constraints. The system performance proposed in this paper is compared with the performance of the existing system. The results show that n-pentane is the best working fluid where multi-objective optimization indicates that the system can generate 63.54 MW of power with thermal and exergy efficiencies of 17.59% and 65.26% and specific cost of 1.7049 USD / GJ at the selected optimal design point. Compared to the existing system, there is a significant improvement in performance both from thermodynamic performance and economic performance.

Utilization Waste Brine Water Separator for Binary Electric Energy Conversion in Geothermal Wells

“…This value shows how much power can be produced with a certain heat input. Thermal efficiency can be calculated using the equation [15]:…”

Düşük Enerji Seviyeli Kaynakla Çalışan Afyon Jeotermal Güç Santralinin Performans Değerlendirilmesi

“…Their evaluation of the plant showed that in double flash energy and exergy efficiency were increased from 16.26% and 40.06% to 17.73% and 50.89%, respectively. Rachmat et al (2018) were conducted anexergoeconomic analysis and optimization of a combined double flash binary cycle for Ulubelu geothermal power plant in Indonesia. The proposed system was used current data and properties of brine exploited from the Ulubelu geothermal well in Indonesia and four working fluid candidates, namely n-Pentane, R141b, R123, and R245fa are used in binary cycles.…”