Determination of the 5 MW Design Case for Power Production at Raft River

Abstract

This paper documents a series of Rankine Cycle studies for power generation utilizing geothermal fluid as the heat source and isobutane as the working fluid. To find the plant configuration which would most effectively utilize the available energy, a parametric study was performed. The study considered the desirability of supercritical, single boiler or double boiler cycles, and the relative boiler temperatures and percentage isobutane flow between split between the boilers in the double cycles for geothermal fluid temperatures of 260°F to 360°F. This study was designed to discover thermodynamic trends which would point to an optimum isobutane cycle for geothermal fluid temperatures in this temperature range. The results of the parametric study were applied to derive a Nominal Design Case for a demonstration plant at Raft River, with a geothermal fluid resource of 290°F.