Utilization of thermoelectric technology in converting waste heat into electrical power required by an impressed current cathodic protection system

Supplying an energy source for impressed current cathodic protection is considered as the main challenge for pipelines corrosion protection in remote areas. The purpose of this study is to construct and evaluate the performance of an impressed current cathodic protection system using waste heat to replace the external electrical power supply. The system consists of four thermoelectric modules producing the electrical power from the hot combusted gas stream. Mathematical modeling and Buckingham Pi theorem were applied to obtain five dimensionless parameters and several models to estimate the system performance. According to the experimental results, the generated voltage, electrical current, and temperature difference have been increased rapidly during the experiment up to 201 mV, 44 mA, and 20 K, respectively. Moreover, mathematical modeling and Buckingham Pi theorem were also utilized to obtain three equations, two nonlinear and one dimensionless equation, to calculate the generated electrical voltage with the maximum error of 1.22%, 9.11%, and 10%, respectively. The results indicate that the temperature difference (between inlet gas and environment) and the figure of merit have a direct effect, and heat sink thermal resistance has an inverse effect on the generated electrical voltage.