Investigation and Mathematical Modeling of Solar- Thermal Desalination with Bubble Pump Technique

Abstract

The objective of this study was to investigate performance of a solar seawater desalination with bubble pump technique. A model was also developed to simulate the system behavior and ultimately to estimate the unit cost of distilled water. The sample of salt solution of 3% was tested in various levels of the bubble pump at 162, 216 and 270 mm or 60, 80 and 100% relatively to height of the bubble pump column, respectively. The experiment was done at a laboratory scale under Chiang Mai climatic condition. The bubble pump model was mathematically developed as a correlation between the distilled water rate, brine water rate, the initial salinity of the salt solution, the outlet temperature of the working fluid from the solar collector, and the liquid level in the bubble pump column. The correlation with the uncertainty of was as given by Md = (-353.83100+2.75650H-0.0065452H2) + (.60750-0.0269416H+0.00006298H2)To The results from the calculation could be fitted with 91.66% of the experimental data with 10% deviation. It was evident from the results that the system with the liquid level at the bubble pump of 60% was the most efficient case. The system could produce distilled water from 3.87 to 6.46 liters per day depending on hours of direct sunshine. The study showed that the lower the reservoir level of the bubble pump, the higher rate of distilled water the system could be produced. The cheapest cost of the production from the solar thermal desalination of seawater by bubble pump technique was 4.32 baht per liter.