Comparative Study of Primary Fluid Flow (PFF) Freeston Method and Numerical Method by Computational Simulation on Steam Jet Ejector at PLTP XXXX

Abstract

In producing better power plant efficiency, steam produced at geothermal wells undergoes reduction of NCG (Non Condensable Gas) percentage. This reduction is followed by steam consumption required by steam jet ejector to separate NCG. NCG percentage variation with PFF (Primary Fluid Flow) mass rate is display to tell the amount saving can be produced. As one of popular methods in predicting the amount NCG reduced in ejector, Freeston method gives suggestion to calculate PFF mass rate ATSR graphic (Air To Steam Ratio). To better produce better prediction, the result of the Freeston method (1) is compared to computational results in this study using PLTP (Geothermal Power Plant) XXXX data. As the change of PFF mass rate required on first and second stage steam jet ejector, it is necessary to remodel GRS (Gas Removal System) at PLTP XXX such as intercondenser and aftercondenser. Simulation and remodeling is conducted for NCG percentage variation: 0.5-3.375% for first stage ejector and intercondenser and 0.5-1.5% for second stage ejector and aftercondenser. The current study found that the average of ATSR percentage difference between Freeston method and computation on first stage ejector is 16.31% while on second stage ejector is 17.60%. PFF mass rate required by first and second stage will increase with increase of NCG percentage. The requirement of mass rate of cooling water condensate on intercondenser and aftercondenser will decrease with increase of NCG percentage.