Thermoelectric generator utilizing boiling-condensation (experiment and modeling)

A thermoelectric generator utilizing boiling and condensation of thermal medium circulating between a boiler and condensers was proposed in this study. Fuluorinert (FC5312) was used as the thermal medium (working fluid). A vertical tube type boiler with an outside forced convective heat transfer and an inside natural convective boiling was chosen. In order to increase the hot side temperature of the thermoelectric module, the hot side electrode was processed into a low-finned condensing surface. A power generating experiment was carried out in a wind-tunnel test bench. Experimental parameters were the inlet temperature of the cooling water, the velocity and the temperature of the hot air. As the results, the thermoelectric conversion efficiency reached 4.6% for a temperature difference of 145K and the boiler efficiency (the ratio of the heat absorbed by boiler from the hot air to the heat that the hot air holds initially) reached 57%. Taking account of the heat loss passing through the thermoelectric module, the system efficiency (the ratio of the power output to the heat that the hot air holds initially) can reach more than 2.2%. Moreover, two types of boiler and two sorts of thermoelectric material are compared. Further, a prediction method for this thermoelectric generator is proposed. Comparing with the experimental results, it is confirmed that the prediction method is effective.