THERMODYNAMIC AND ECONOMIC ANALYSES OF TWO GENERATIONS OF KALINA CYCLE AS BOTTOMING CYCLE FOR GEOTHERMAL POWER PLANTS

• Main Author: Ardiansyah Weiman, Reza
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49751
• Institution: Institut Teknologi Bandung

Based on Government Regulation number 22 in 2017, Indonesia needs to increase the use of new and renewable energy as its source of energy from 9% in 2014 up to 23% in the year 2025. One of the new renewable energies that is abundant in Indonesia is the geothermal energy. There are several ways to increase the Indonesia’s geothermal power plant capacity and one of them is by installing bottoming cycle to generate electricity from the brine thermal energy before reinjecting it back to earth. Due to its working fluid’s low boiling point, The Kalina cycle is the proper cycle to use as a bottoming cycle. Until 2020, there are two generations of the Kalina cycle. In this bachelor thesis, both thermodynamic and economic analyses are conducted on both generations to determine the best cycle for a bottoming cycle. The KCS 11 cycle was chosen to represent the first generation and the SG-2d cycle was chosen to represent the second generation because both of these cycles are designed to utilize 150-200oC brine. In this bachelor thesis, each cycle was modeled and optimized using HYSYS v10 software. After optimum point of each cycle was acquired, the total investment cost, payback period, and gross revenue was estimated. From the result of the optimization, the SG-2d cycle proved to have the superior thermal efficiency compared to the KCS 11 cycle with the average of 1,26% higher thermal efficiency for the 150-200oC temperature range. However, the KCS 11 cycle is the more economical cycle with the average of 36,5% higher gross revenue generated compared to the SG-2d cycle.