Search

The energy and exergy analysis of a single slope solar stills using ceramic type rectangular and circular magnets in the basin was carried out in this study and compared to conventional solar still. The results showed that the rectangular magnet solar still (RMSS) had higher hourly productivity of about 5.8% and 13.7% than circular magnet solar still (CMSS) and conventional solar still (CSS), respectively. For 12 h of reading, the cumulative productivity in RMSS, CMSS, and CSS was observed at 3.15 kg/m2, 2.82 kg/m2, and 2.15 kg/m2, respectively. Compared to CMSS and CSS, the RMSS has enhanced its energy efficiency by 4.9% and 6.9%, respectively. The observed exergy efficiency in RMSS has increased to 3.4% and 17.2%, respectively, than CMSS and CSS. Due to sensible heat absorbed by magnets, the amount of exergy lost in the RMSS and CMSS basin is much less than in CSS. In economic analysis, the estimated produced water cost (PWC) of RMSS is 4.5% and 22.2% lower than the PWC estimated in CMSS and CSS, respectively. Overall, the results showed that the magnetization of saline water made the solar still work much better.

In the field of thermodynamics, entropy is a measure of the degree of disorder of the system considered focus. The direct measurement of entropy for microscopic systems involving molecule-level variations exists. However, for a macroscopic system, it still remains a challenge. The temperature reading is used as the primary index for understanding the quality of heat. In certain applications, the induced errors in the temperature measurement create complexity in decision making. One such case is the measurement of human body temperature for fever-like symptoms. This research aims to develop a direct entropy measuring device to indicate heat transfer for macroscopic systems. The developed device measured the mean entropy of the human body as 0.042 and 0.146 kJ/K during the daytime and nighttime, respectively. In comparison to the simulated entropy values, the measured values differed by 4% during the trials on the human body. Key decisions on macroscopic systems based on mild temperature variations can be made confidently with the measured entropy values.