Thermoelectric power generation in a top-heat-collection and vapor-bubble-driven thermosyphon

Top-heat-collection and vapor-bubble-driven thermosyphon systems circulate a working fluid in a closed-loop pipe by utilizing the vapor-bubble buoyancy, effectively transporting heat from a heated top section to a cooler bottom section without external power. However, weather conditions can affect the flow of working fluid in a pipe, leading to issues including intermittent flow, sudden boiling, and pipe failure, thereby shortening their service life. To solve this problem, this study proposes controlling the pressure inside a pipe to transform an intermittent flow into a continuous flow. However, if an external power source is used for controlling the pressure, the top-heat-collection and vapor-bubble-driven thermosyphon loses its advantage of not requiring external power. Therefore, this study ensured that the generation of pressure-control electricity by the thermoelectric elements in the heat-exchange section is not related to heat transport in the thermosyphon, that is, in the heat-exchange section where the vapor is condensed. Experimental results show that the proposed model successfully generated approximately 28.5 mW of electricity without disturbing heat transport.