U-Tube Downhole Heat Exchanger Performance in a 4-inch Well Rotorua, New Zealand

Abstract

Regulations resmcting the withdrawal of geothermal fluid from shallow wells in Rotorua have created interest in the Downhole Heat Exchanger as a low impact alternative method of utilizing the resource. Adapting existing production wells to DHE use is of A series of tests has been conducted on a U-tube DHE installed in a diameter well which previously provided a steam water mixture to heat the Works and Development Corporation workshops in Te Ngae Road, Rotorua. Flow rates and temperatures through the DHE have been varied to test their influence on the heat load obtained. The thermal response of the well has been observed during quench tests and periods of DHE operation. A study of fluid temperatures inside the heat exchanger tubes has resulted in a better understanding of the heat transfer processes involved in a typical RotoruaDHE well system.