Internal Technical Report, 60 KW Test Facility Heat Exchanger Specification

This report presents the thermal specifications for three heat exchangers (preheater, boiler and condenser) to be used in a 60 kW prototype power plant installed at the Raft River geothermal facility. This prototype plant is unique in that it will utilize a working fluid of 90% propane--10% isopentane (by weight) operating at super-critical pressures in a binary geothermal cycle to extract energy from a 280 F geothermal resource. Studies have shown that this super-critical cycle can provide a net performance about 20% higher than that of the optimum dual-boiling isobutane cycle currently designed for the 5 MW Raft River pilot plant