A new type of thermoelectric transport is described, consisting of pulses of charge carriers, which “fly” periodically through the external circuit from the hot end of the sample to the cold end, with a determined duration of the “on” and “off” times of the electric contacts, while maintaining continuously the thermal contacts. It is shown that such a non-equilibrium ideal thermal “machine” works cyclically with an improved efficiency compared with efficiency of the thermoelectric devices operated in an equilibrium transport regime, but the electric flow and power are increased, as a consequence of concentrating the charge carriers on pulses of small spatial extent. The machine is reversible, in the sense that it can operate either as a thermoelectric generator or as an electro-thermal cooler. So, it is described a new thermoelectric generator special designing to fulfill the needs of pulse operating and a set up able to measure the thermoelectric parameters of Non Steady-State (pulse) operated generators. Preliminary measurements show a minimum two times increasing of delivered electric power, using same heat power input, when we are working in pulse operation. It is confirmed existence of a lower limit of frequency where the electric power starts to increase comparing with DC operation and a superior limit of frequency, where the increasing is too low to be taken into consideration. All these results are a strong confirmation of “pulsed thermoelectricity” theory.
Thermoelectric Generator Pulse Operated
AUTHORS: Marin NEDELCU, Marian APOSTOL, Viorel Şerban STANCIU, Ion BÂRSAN