Wellsite verification testing of an advanced geothermal primary heat exchanger (APEX)

Abstract

The well-site test phase is described of a research program conducted by Aerojet Liquid Rocket Company to establish the feasibility of using a recirculating solid bed material to eliminate heat exchanger fouling in geothermal service. The concept was directed towards application as the primary heat exchanger in a geothermal power plant which utilizes a binary cycle. The APEX approach was shown to be effective for condenser operation with fouling cooling water. Similarly, APEX could be applied for geothermal direct heat utilization, for example, the vapor generator in an absorption refrigeration system. Phase I of this program culminated in a laboratory demonstration of APEX concept feasibility with brine simulants. Testing under the current project phase of the research effort was conducted at the Geothermal Component Test Facility at East Mesa, California. Technical feasibility was established by testing the effectiveness of the bed material in preventing the fouling of a heat exchanger test section. The elimination of fouling was demonstrated using both geothermal well water and facility cooling water as the fouling fluids.