Experimental investigation of electricity generation from geyser boiling of working fluid during thermal performance of the thermosyphon heat pipe

Abstract

The following study introduces a novel approach to generating electrical power by utilizing a thermosyphon heat pipe (THP) using geyser boiling of the working fluid. In the initial design of this concept, the geyser boiling in the evaporator causes the induction of a solenoid through the oscillation of a magnet. In this regard, the electricity generation module was designed and optimized through a trial-and-error process to provide the highest electrical and thermal performances of the novel Oscillating Magnet Thermosyphon Heat Pipe (OM-THP) system. The present study examines the relation between the electrical and thermal performances of OM-THP under different heat input and filling ratio conditions. Two filling ratios, 20%, and 40%, were evaluated for the working fluid of water. The heat input was increased from 25 to 250 W. The open circuit voltage value was measured and found to have a maximum peak-to-peak range of 0.3–0.9 V. The maximum average and peak electric power generated are 5.54 μW and 1.54 mW, respectively. The findings indicate that the thermal resistance measurements of THP and OM-THP exhibit a negligible difference. This means that the thermal performance of the THP is almost unaffected by the installation of the electricity generation module, which is a prominent feature of the electricity generation module devised in this work. In addition, a novel thermal-electric index was developed to identify the conditions under which OM-THP exhibits the highest thermal and electrical performances. This index revealed that the optimal operating condition of OM-THP is a 20% filling ratio and 125 W heat input with a thermal-electric index of 0.84.