DESAIN DAN FABRIKASI SISTEM PEMBANGKIT TENAGA PADA SIKLUS ORGANIC RANKINE CYCLE (ORC) UNTUK PROTOTIPE OCEAN THERMAL ENERGY CONVERSION (OTEC)

Abstract

The OCEAN THERMAL ENERGY CONVERSION (OTEC) system utilizes
the temperature difference between warm surface seawater and cold deep seawater
to generate energy. This study develops a laboratory-scale OTEC prototype based
on the Organic Rankine Cycle (ORC), designed to operate under low-temperature
differences. The main focus of this research is the use of a Finned Tube Heat
Exchanger as the evaporator to enhance heat absorption efficiency, as well as the
utilization of a modified rotary-type compressor functioning as a turbine to extract
energy from the working fluid. Refrigerant R22 is used due to its low boiling point,
stable thermodynamic characteristics, and suitable operating pressure for low
temperature ORC systems. The system is designed to operate as a closed ORC cycle
with key components including the evaporator, turbine, condenser, and refrigerant
pump. Based on the calculation results, the turbine produces 0,04187 kW of power
with an isentropic efficiency of 65%. On the evaporator side, the UA value is
calculated at 220 W/K, with a fin surface area of approximately 0,01071 m², and a
fin efficiency of 1. Initial testing results show that the system can operate stably
with baseline performance appropriate for laboratory simulation. This prototype
design is expected to serve as a foundation for further experimental development of
more practical and economical low-temperature energy conversion systems.