An experimental investigation of a desalination system based on an evacuated tube collector coupled with a heat exchanger

Abstract

AbstractAccording to the report published on global water stress, the world will face a huge water crisis by 2040, due to continuous decay of freshwater resources and an increasing population of human beings. To fulfill this increasing demand for freshwater, we need to find a new source. As the sea contains most of the water available on earth, desalination of sea water can be a solution. Furthermore, the use of solar energy for desalination process can make it a sustainable solution. This is why it is very important to work on solar thermal desalination system. In recent years, a lot of research has been reported on solar still integrated with evacuated tube collector (ETC) to improve its efficiency and productivity. But the problem of salt deposition in evacuated tubes was very common in these systems. So in the present work, a new solar thermal desalination system based on ETC is developed. In the present system, ETC is integrated with a storage tank, which further has a heat exchanger. Therminol 55 is used as a working fluid, which transfers heat from ETC to saline water. System performance is evaluated in terms of productivity, energy efficiency, exergy efficiency and economic feasibility. The productivity of the system is 4.2 L/m2/day. The average energy efficiency delivered by the system is 43.92% and average exergy efficiency to be 9.53%. The maximum mass flow rate of thermic fluid is 0.003962 kg/s. The freshwater production cost by the desalination system is 0.022 $/L.