Avaliação de um sistema de dessalinização via osmose inversa com uso de energia solar fotovoltaica.

Abstract

The work presents the results obtained from a water production system potable from the desalination process via reverse osmosis and the use of photovoltaics as an energy source. Analyzing solar radiation for the city of Campina Grande, based on data provided by the Solarimetric Atlas, Sundata and Radiasol, a great similarity in their values ​​is obtained, which gives us reliability in these results and allows verifying that the region has a high rate of solar irradiation. With these data, the year can be divided into two periods: summer and winter. The first period would from September to April with a minimum of 7 hours of sunshine per day and the second from May to August with a minimum value of 4 hours of sun per day. The great demand for sun during the summer in allows you to desalinate a considerable amount of water, already in winter as insolation decreases, the need for potable water can be met by harvesting rainwater. the consumption energy of a desalinator was evaluated using the ROSA 6.1 software with a water of concentration feed varying between 1,000 and 3,500 mg/L. With recovery of 15% and using 1 membrane; getting 0.3 m 3 /h of permeate, 2.73 kWh/m3 of energy are used and

with 2 membranes a double flow rate is obtained using 2.81 kWh/m3

. already with a recovery of 30% this same process can be carried out with a reduction in the energy consumption of 1.45 kWh/m3 (0.3 m

3 Ih) to 1.44 kWh/m3 in obtaining 0.6 m 3 /h of permeate. Therefore, the latter would be ideal, since a greater amount of potable water is obtained with a smaller energy expenditure. The tested solar desalinator showed that with a concentration of 3,500 mg/L and a pressure of 8 kgf/cm2

, it produces 0.252 m3

/h with a recovery of 40%. For Therefore, the system needs a power of 370 W and has an average energy consumption of 1.5 kWh/m3 . The number of photovoltaic panels used is too large in relation to the power consumed by the DC motor due to the absence of an "MPP Tracking" system, which is not a electronic circuit functions. The simulation performed to obtain the permeate and the cost of energy, the greater the amount of permeate obtained, the greater the number of people served. When comparing the results of the simulator with those of the desalinator, we noticed a increase in practical values.