A Simple Device for Measuring Fouling in a Heat Exchanger Tube

Abstract

A simple, electric-heating-tape-wrapped and insulated tube device has been developed by Lockheed Ocean Systems (LMSC) to monitor the thermal resistance of fouling (R F ) from seawater inside a simulated ocean thermal energy conversion (OTEC) heat exchanger tube. It is compared with another directly-heated monitor that has been used by others in many biofouling measurement programs and with an indirect method in which a secondary fluid would be electrically heated. An analysis of experimental uncertainty in R F determination is presented for the LMSC and indirect methods. Representative R F data for aluminum and copper-nickel LMSC devices are presented. The three methods are compared subjectively with respect to ten cost, use, and performance criteria, and the LMSC device has a first-place ranking for seven of the criteria.