Scaling and turbine performance assessment of Maibarara 1 geothermal power plant

Abstract

Turbine scaling deposition is one of the problems encountered in the first year of operations at Maibarara 1 geothermal power plant (M1GPP). To address the issue, the installation of a turbine blade washing system was recommended, but after two years of operation using the blade washing system, the turbine was inspected and scaling was still found. Data used for the analysis presented here are the results of sample deposits collected during the inspection and from the steam chemistry condensate as well as data of steam flow, turbine chamber pressure and other operational data. The turbine performance is calculated based on a Scilab modelling simulation using Stodola’s cone (or ellipse) law equation. Based on the chemical analysis and the simulation the present scaling source is the washing fluid used for blade washing. Based on the assessment of the results, possible mitigation methods are presented to address the scaling formation in the turbine with regard to the performance of the turbine.