| Abstract |
BPPT has developed and operated a 3MW Geothermal Power Plant (GPP) of condensing type technology in Kamojang - Indonesia, which is the first prototype GPP manufactured by national companies. The GPP design is based on KMJ-68 well data characteristics, owned by Pertamina Geothermal Energy (PT. PGE), atmospheric conditions around the plant, and steam turbine specifications designed in reverse engineering. The manufacturing process of the main components of the plant such as turbines, generators, condensers, etc. carried out by the local manufacturer. This paper discusses the design of PFD, performance, and reliability of this plant during 3x24 hours continuous synchronous testing to the 20kV local power grid. Until the end of the testing in May 2019, the plant has produced 251MWh of electricity, with the highest load of 2.2 MW. During testing, the steam pressure and temperature entering the turbine are relatively constant around the design value. However, there is a loss of steam pressure entering the turbine by the strainer and reduced condenser vacuum which causes T/MWh from the plant to be relatively high. All process parameters, particularly vibrations, bearing temperatures, are all within the safe limit. This plant is very reliable in responding to local electricity network loads that often fluctuate. The thermal efficiency of the turbine generator is around 55%. This can still be improved by overcoming the problems of pressure loss in the filter and reducing condenser vacuum. The condenser vacuum can be optimized by keeping the cooling water temperature low. From the last inspection, a number of water spray nozzles in the cooling tower are clogged by dirt which is thought to be the cause of the increase in cooling water temperature. Thus it can be concluded that the plant is ready to operate with the full load by increasing the performance of the cooling tower and strainer. |