Study of Operation of the Thermoelectric Generators Dedicated to Wood-Fired Stoves

Krzysztof Sornek

doi:10.3390/en14196264

Abstract

Thermoelectric generators are devices that harvest waste heat and convert it into useful power. They are considered as an additional power source in the domestic sector, but they can also be installed in off-grid objects. In addition, they are a promising solution for regions where there is a lack of electricity. Since biomass heating and cooking stoves are widely used, it is very appropriate to integrate thermoelectric generators with wood-fired stoves. This paper shows the experimental analysis of a micro-cogeneration system equipped with a wood-fired stove and two prototypical constructions of thermoelectric generators dedicated to mounting on the flue gas channel. The first version was equipped with one basic thermoelectric module and used to test various cooling methods, while the second construction integrated four basic thermoelectric modules and a water-cooling system. During the tests conducted, the electricity generated in the thermoelectric generators was measured by the electronic load, which allowed the simulation of various operating conditions. The results obtained confirm the possibility of using thermoelectric generators to generate power from waste heat resulting from the wood-fired stove. The maximum power obtained during the discussed combustion process was 15.4 W (if this value occurred during the entire main phase, the energy generated would be at a level of approximately 30 Wh), while the heat transferred to the water was ca. 750 Wh. Furthermore, two specially introduced factors (CPC and CPTC) allowed the comparison of developed generators, and the conclusion was drawn that both developed constructions were characterized by higher CPC values compared to available units in the market. By introducing thermoelectric modules characterized by higher performance, a higher amount of electricity generated may be provided, and sufficient levels of current and voltage may be achieved.

Highlights

Published: 1 October 2021The use of wood-fired stoves (WFS) is common in European countries and NorthernAmerica, providing CO2 -neutral energy for residential heating [1]
The average value of the hot surface temperature was ca. 523 K, which was the optimum value from the point of view of thermoelectric modules used in the developed thermoelectric generators (TEGs)
Power generation with the use of TEG is increasing in popularity due to the decreasing prices of the TE modules and the high costs of consuming electric power from the grid

Summary

Introduction

Published: 1 October 2021The use of wood-fired stoves (WFS) is common in European countries and NorthernAmerica, providing CO2 -neutral energy for residential heating [1]. The use of wood-fired stoves (WFS) is common in European countries and Northern. WFSs are devices dedicated to heating purposes that provide low-cost heating and an aesthetic atmosphere from burning wood. Micro-cogeneration is a promising solution because it allows one to increase the energy and economic efficiency of stove operation and contributes to reducing carbon dioxide emissions in countries where electricity production is mainly based on fossil fuels [2]. Thermoelectric devices are silent and do not generate vibrations since their operation does not require the contribution of mechanical energy [3]. Many thermoelectric materials are currently explored for power generation applications, such as GeTe [4], PbTe [5], half-Heusler [6], and skutterudites [7]

Methods

Results

Conclusion