Conversion of a Flash Power Plant to Organic Rankine System for Olkaria Geothermal Power Plants

Abstract

Organic Rankine cycles are the best thermodynamic cycles for application in low temperature heat energy sources. Most geothermal power plants globally use the single flash technology to produce electricity. Depending on the thermodynamic conditions, it is possible to install an organic Rankine plant as a bottoming plant to a conventional geothermal plant. In this study, is an organic Rankine plant to utilize waste heat in used geothermal fluid living flash stations SD2 and SD3 for Olkaria Power station in Kenya is proposed. The study showed that up to 73.9MW power can be generated from waste brine for Olkaria IV geothermal field before reinjection in. The main objective of this study was to develop an ORC plant running to generate electricity from brine leaving flash tanks to reduce energy wastage in brine and on n-pentane as the working fluid installed on this brine stream will have a gross capacity of 7.6 MW.