| Title | Optimization and Design of Tatara Binary Geothermal Power Plant in Beppu, Japan |
|---|---|
| Authors | J. UWERA, R. ITOI, S. JALILNASRABADY, K. KOJIMA |
| Year | 2016 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Organic Rankine Cycle, Optimum design, Low-temperature, Power generation, Tatara binary plant, Japan. |
| Abstract | The Tatara binary geothermal power plant is a small scale plant located in Beppu, Oita prefecture, Kyushu Island, Japan, with installed capacity of 70 kW. This plant started operation in August 2014 using geothermal fluid at about 106oC from geothermal well of 550m, and R245fa as a working fluid. It has the capacity to produce 60 kW as gross turbine work output. In this plant the geothermal fluid produced from a well is first heat exchanged with ground water which is further heat exchanged with the working fluid. To avoid any chemical complications in the heat exchanger, ground water was used as a heat medium with the working fluid, R245fa. In this plant, heat depleted geothermal fluid after heat exchange and cooling water are used for hot water supply by mixing with groundwater. Mathematical models for energy flow was developed and implemented in Engineering Equation Solver program. This study shows the working conditions of the Tatara binary plant and it was found that the plant is already operating closely to the optimal working conditions, its overall thermal efficiency was found to be 8.3% according to the developed model while the system efficiency was found to be 5.8%. |