| Abstract |
Injection brine discharged from separators in Wayang Windu geothermal field still has a relatively high temperature (178.5 oC) to be utilized as the heat source to generate electricity using Organic Rankine Cycle (ORC) system. There are two types of ORC system that has been reviewed, simple ORC system and modified ORC system with recuperator. Recuperator is a heat exchanger that uses heat from working fluids to reduce heat duty of condenser and pre-heater. ORC system needs a cooling system for condenser. Cooling systems that has been investigated are air cooling system and water cooling system. Therefore, there are four scenarios that have been investigated, simple ORC with air cooling system, simple ORC with water cooling system, modified ORC with recuperator and air cooling system, and modified ORC with recuperator and water cooling system. Methodology used was thermodynamics calculations from ORC system and the cooling system. Air conditions such as dry bulb temperature, wet bulb temperature, and relative humidity has been recorded for every hours, started from 1st of June 2016 until 31st of May 2017. The fluctuation of fan power from ORC has been investigated, which is influenced by ambient air conditions, and will significantly reduce ORC net power. From four scenarios that have been investigated, the greatest electrical energy is produced by modified ORC system with recuperator and water cooling system, that produces 28.792.477 kWh of electricity in a year, where the least electrical energy is produced by simple ORC system using air cooling system, which produces 27.333.512 kWh of electricity, that only has 5,20% of difference. This not too significant differences lead to the need of further researches to decide which scenario is suitable to be installed for Wayang Windu geothermal field, such as land availability, make-up water availability, and economical analysis for each scenario. |