Innovative solar natural vacuum desalination system

The main target of the work is a design of an innovative solar natural vacuum desalination (SNVD) system and improve performance of such systems. The natural vacuum is developed by raising up an evaporation chamber to 9.8 m above the ground. The waste heat is efficiently utilized in that system to minimize the system heat loss. The fresh water is first preheated by condensing vapor from the evaporation chamber before it is heated by a flat-plate collector as a heat source of the evaporation chamber. On the other side, the sea water is preheated by the produced warm water, and it is reheated by the exit brine water before it is supplied into the evaporation chamber. A mathematical model and a transient simulation were established to investigate the annual performance of system. A heat balance of each system component was provided to estimate the inlet and outlet temperature and flow rate of it. Moreover, the collector area was estimated based on assumed mass flow rates of both feed sea water and coolant water. It was found that the system can produce a daily production of 6.2 L of pure water per a quadratic meter of collector on annual average basis. That Productivity can be estimated as 1.12 L of water per kWh solar radiation. Accordingly, the evaporation rate was estimated as 2.82% while the gain output ratio (GOR) was obtained as 0.63. The system performance can be accepted compared with the corresponding published systems.