Performance of a single-effect desalination system operating with different tube profiles and materials Original Research Article

In this paper, the effects of tube materials and profiles on the thermal performance of a single-effect evaporator have been investigated. Three different types of tube profiles, such as, single-fluted aluminum tube, smooth Cu-Ni (90-10) tube and corrugated Cu-Ni (90-10) tube have been used for the design of the evaporator. Simulated seawater with variable concentrations (25,000–35,000 ppm) has been used as feed. A series of experiments under different operating conditions has been conducted. The effects of the operating variables on the production rate, performance ratio, specific heat transfer area and overall heat transfer co-efficient of the evaporator have been investigated. Flashing effect has been found to have a significant impact on the performance ratio of the system. The lowest specific heat transfer area has been found for the corrugated Cu-Ni (90-10) tube profile. The system performance ratio tends to decrease with the increase of the saturation temperature in the evaporator. The system can yield product water with average concentrations of 15–20 ppm. A numerical model of the system has been developed. A non-equilibrium analysis of the evaporator has also been made. The experimental and predicted results obtained from simulation show good agreement with the actual plant performance.