Geothermal Heat Transfer - Field Tests at Broadlands

Abstract

A pilot scale heat exchanger, designed to generate basic heat transfer and pressure drop data for the turbulent flow of geothermal fluids carbon steel tubes, has been operated at Broadlands since 1981. Results are given for operation with separated water flowing alone and with gas, and for separated steam and mixtures. These show enhancement of heat transfer rates when gas flows with the separated water, and high heat transfer rates for mixtures. The decline in performance during a month test using separated water, cooled from to approximately shows a low silica deposition rate and thus a low annual fouling rate. Three commercial cleaning methods removed this silica scale with varying degrees of success. Fouling tests with two other geothermal fluids are planned. Operating problems with the test rig are noted.