Special Function Instruments for Binary Cycle Geothermal Power Plants

Abstract

Three special instruments have been designed to support plant operations at the Heber geothermal power plant in Heber, California. All are aids to give operating information which no commercial instruments can provide. The first is a package for determining CO2 breakout conditions for a particular brine. Brine is sampled continuously at either the wellhead or the plant inlet. A temperature pressure curve is generated which will span all possible operating combinations. That information tells designers or operators what pump pressures must be used to keep the CO2 in solution. A second package unit will detect the presence of ppm levels of isobutane in either brine or water streams. It samples actual flowing brine streams continuously. The function is to alert operators when leaks are occurring in heat exchangers. A final unit sense water in flowing hydrocarbon streams. The sampled streams can be either liquid or vapor. Sensitivity is close to actual solubility limit for water in isobutane. This device warns operators when their hydrocarbon has been contaminated with brine (cooling water).