Experimental Investigations on a Multi-Stage Tower Type of Solar Desalination Unit
Abstract
A multi-effect distillation is one kind of practical technology which can be combined with solar heating system to produce fresh water from seawater. El-Nashar and Qamhiyeh (1990) had calculated the performance of MES evaporators under unsteady state operating conditions. The performance of a multi-effect solar desalination system was investigated by Abdel Dayem (2006) on the base of experimental study and numerical calculation. Zheng et al. (2006) developed a new kind of solar desalination unit, which is a triple-stage desalination unit, and the performance of the unit was tested under steady state conditions. Afterwards Chen (2007) and Chen (2009) continued to investigate the parameters optimization and the heat and mass transfer of the unit (Zheng et al. 2006) by simulation. In this paper one quadruple-stage tower type of solar desalination unit is developed on the basis of the unit (Zheng et al. 2006). The influences of the parameters on the fresh water production and the performance ratio of the solar desalination unit will be tested indoors under steady state conditions. The parameters of the unit are the flow rates of the heating water for the evaporator and the cooling water for the condenser, the flow rate of the feedstock, the inlet temperature of the heating water for the evaporator and the cooling water for the condenser, the start-up pressure inside the unit, etc, which will be classified into key parameters and secondary parameters after the experimental study based on how much the influences of the parameters are on the production of fresh water and the performance ratio of the unit. The experimental results also can be used to validate a simulation model proposed for the theoretical calculation for multi-stage tower type of solar desalination units and the optimization of the parameters.