Electricity production is an important issue for our life. At present, power generation depends on fossil fuels. Excessive fossil fuel consumption by human activities has led to serious atmospheric and environmental problems including global warming, greenhouse gas emission, climate change, ozone layer depletion and acid rain. One of the energy generation methods to reduce the impact of natural disasters is thermoelectric conversion technology.
A thermoelectric generator produces electricity by using the thermoelectric effect. Thermoelectric generators consist of several sets of thermoelectric modules inserted between two heat exchangers. Each module is then composed of several tens to hundreds of pairs of thermoelectric couples connected together electrically in series and thermally in parallel, which directly convert some of the thermal energy that passes through them into electricity. However, the defects of thermoelectric technology are low energy-conversion efficiency and high material cost.
So far, different plans to get a higher degree of its efficiency have been suggested. Most of them, however, based on the main dimension of heat exchangers, focus on the influences of factors including temperature, velocity and flow direction in fluid, and the type of its internals, but not on the effect of the array of thermoelectric devices.
Kim Kwang Jin, a researcher at the Semiconductor Institute, has carried out a coupled fluid-solid numerical simulation of the heat exchanger internal flow field of a low-power thermoelectric generator using the waste heat from stove.
He carried out thermal field simulations in the heat exchanger with fins and without fins and an analysis of the shape of the inner fins, which were in good agreement with the results of the previous studies. Then, he determined the design parameters of the thermoelectric generator through the simulations according to the main dimensions, the number of inner fins and the arrangement of thermoelectric elements of the heat exchanger. He found that the performance of the heat exchanger is better, when the main dimensions of the heat exchanger is 250×200×30mm, the array of thermoelectric devices is linear and the internal topology of the heat exchanger is straight with 9 fins.
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