|Budget Amount *help
¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 1993 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1992 : ¥1,000,000 (Direct Cost : ¥1,000,000)
The free energy available in the process of mixing river water and seawater corresponds to a power head of about 250 m. A dialytic battery with ion-exchange membranes can directly convert this salinity difference energy into the electric energy. In the present study, a new system of the solar membrane cell has been proposed in which the dialytic battery is coupled with the solar still. In this system (abbreviated as SMC) the solar energy is stored through the solar still as the salinity difference energy between fresh water and concentrated seawater, and by the dialytic battery it is converted into the electricity according to demand.
A laboratory scale SMC has been constructed and its performance was tested ; Especially, three types of dialytic battery with different scale has been tested in order to investigate the scale up effect of the dialytic battery. The open circuit potential V_0, and the power output W have been measured as functions of fresh water flow rates and the operating temperature ; from these measurements, the maximum power W_<max> and the internal resistance of the battery were determined. The power became several times larger than that produced under ordinary conditions. In the largest dialytic battery (number of membrane pairs is 200 and the effective area of membrane is 475 cm^2), V_0 and W_<max> reached upward of 10 V and 1000 mW.Tests results have been compared with those obtained from the calculated on the basis of a numerical model. It was shown that the test results were in good agreement with the calculated.