Investigation of the Effect of Natural Convection Cooling Caused by the Chimney Effect on the Improved Solar Thermoelectric System

Abstract

In this study, the effect of a solar thermoelectric generator (TEG) on electrical energy production was investigated in detail by utilizing the chimney effect in a system designed and fabricated. By connecting six thermoelectric generators in series within the system, the aim was to maximize the voltage increase and thus achieve usable energy production. The manufactured system basically consists of a chimney unit, an upper heat chamber and heat sink placed inside the chimney, a lower heat chamber and heat pipes and thermoelectric generators placed inside evacuated tubes. Thermoelectric generators, which provide the system's power generation, are sandwiched between the upper heat chamber and the heat sink. In the manufactured system, open circuit voltage, solar radiation, thermal temperature values and wind speed data were collected during the experimental measurement days, and the maximum output power and Seebeck coefficients were calculated from these collected data sets. For this purpose, a portable chimney was constructed from the system and measurements were taken from the system with and without the chimney on different test days. Experimental measurements were taken at 41 degrees 14 ' N, 36 degrees 26 ' E with sea level on August 22 and 27, 2024. The data was collected from 10 a.m. to 2 p.m. The highest open circuit voltage obtained on the day of the experimental measurement, when the system was used with a chimney, was 10.74 V, and the solar radiation value at that time was determined to be 778 W/m2. On the other hand, the highest open circuit voltage obtained on the experimental measurement day when the chimney was not in use was 9.09 V and the solar radiation value measured at that time was 812 W/m2. A numerical model Computational Fluid Dynamics (CFD) for the TEG system with the chimney was also included in the study. Model results were validated with respect to cold side temperature and open circuit voltage. In the numerical model, the highest open circuit was calculated 10.72 V.