Waste heat from industries such as steam power plants can be utilized to meet the world’s electricity need. However, it cannot be converted efficiently to electric power by using conventional power generation methods as opposed to a technology called Organic Rankine Cycle (ORC). ORC is one of the power plant systems that is a modification of the Rankine Cycle using organic working fluid. In this research, ORC was designed and manufactured using R-134a as working fluid and helical heat exchanger as evaporator and condenser. The design of ORC systems based on simulation using Cycle Tempo 5.0 with evaporator temperature of 90°C, condenser temperature of 10°C, inlet pressure of pump of 0.55 MPa, and inlet pressure of turbine of 0.79 MPa. The results of this study showed the length of tube evaporator and condenser of 10.61 m and 10.56 m, respectively, with system efficiency achieved at 3.8%. Based on experiment, with evaporator temperature of 95°C, condenser temperature of 10°C, inlet pressure of pump of 0.48 MPa and inlet pressure of turbine of 0.52 MPa so resulted of system efficiency of 3.33%.

Organic Rankine Cycle (ORC) system is a modification of the conventional Rankine cycle to generate electricity from the utilization of low-grade temperature heat sources. Experiment on ORC systems was conducted to analyse the performance of a small scale ORC system with 1 kW capacity using R134a as working fluid. A helical type of evaporator and condenser were used as heat exchangers and a scroll type car compressor was used to generate power with variation in heat source temperatures of 75°C, 85°C, and 95°C. Turbine power is calculated theoretically based on the experimental data obtained due to the turbine was not able to rotate. This experiment results show the optimum efficiency and theoretical power of ORC is respectively 3.33% and 279.58 Watt with inlet pressure and temperature of turbine are respectively 1.25 MPa and 67.7°C.

Renewable energy sources such as solar heat, wind energy, geothermal, biomass and exhaust heat is one way to overcome the crisis of energy and environment in the world. Organic Rankine Cycle (ORC) is a power generation system modified from Rankine Cycle by using organic liquid with low boiling point as working fluids such as R-134a, therefore various types of heat sources can be use. This research was design and manufacture organic Rankine cycle by using R-134a as working fluid with solar collector as the source of energy. The design of this research resulted in the length of the evaporator tube is 14.5 m, length of condenser is 13.9 m and the length of solar collector tube is 9.4 m. The helical Diameter of evaporator and condenser are 250 mm, and the high of helical evaporator 290 mm and condenser 280 mm. Organic Rankine cycle system is designed to produced 534.4 Watt, but when the experiment is carried out the system generates energy of 305 Watt with the efficiency of 4.30%