Thermoelectric generator utilizing boiling and condensation (experiment and modeling)

R. C. Chu1, K. Kadotani1, T. Tanimura1, T. Shintani1, T. Hatanaka1, S. Nishio2

1Komatsu Ltd., 1200, Manda, Hiratsuka-shi, Kanagawa-ken, 254-8567, Japan

2Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-ku, Tokyo 153-8505, Japan

A thermoelectric generation system utilizing boiling and condensation was proposed in this study. The boiler is the type of the vertical pipes with a forced convective heat transfer outside and a natural convective boiling inside. In order to increasing the temperature of the hot side electrode, a low-finned condensing surface is directly used as the hot-side electrode of the thermoelectric module. An experiment generating electricity was carried out using FC5312 as the medium at a wind-tunnel test bench. Experimental parameters were the temperature of the cooling water, the velocity and the temperature of the heated gas. As the results, the efficiency of the thermoelectric conversion reaches 4.6% for a temperature difference of 145 degree and the efficiency of the absorbing heat for the boiler reaches 57%. Taking account of the heat loss passing through the thermoelectric module, the system efficiency becomes 2.2% at maximum. Further, a prediction method for this thermoelectric generation system was proposed. Comparing with the experimental results, it is conformed that the prediction method is effective for the thermoelectric generator utilizing boiling and condensation.