Studying different design parameters of a microwave preheating system in solar desalination

An increasing number of microwave radiation applications have led to a large body of research on the effects of microwave radiation on heating. The effect of different design parameters was analyzed on the microwave-induced heating of saline water. In a completely randomized factorial experiment with three replications, effects of four salinity levels (0, 1,000, 10,000, and 30,000 ppm), three volume levels (100, 300, and 500 ml), and three power levels (200, 600, and 1,000 W) on heating time were studied. ANOVA results showed that the effects of power, volume, and salinity as well as all interactions were significant at the 1% level. The heating rate was calculated for heating water from 20 to 90°C. Heating rate varied from 0.0183 to 1.531°C/s, depending on the microwave power, volume and salinity. Results demonstrated that heating rate decreased with increasing salinity and increased with increasing microwave power and volume.