OPERATION OF MULTI-EFFECT MULTI-STAGE DESALINATION COUPLED WITH A SALINITY-GRADIENT SOLAR POND

摘要

Thermal desalination by salinity-gradient solar ponds is one of the most promising solar desalination technologies, and has been studied in the United States and several other countries. In order to improve the thermodynamic efficiency and economics of this technology, a multi-effect, multi-stage flash distillation (MEMS) unit has been tested at the El Paso Solar Pond over a broad range of operating conditions, including feed water source, operating temperature, and concentration of reject brine. The total dissolved solids (TDS) level of feed water ranged from 1,000 to 58,000 milligrams per liter (mg/l), and the quality of distillate product was maintained at less than 5 mg/l TDS. The test results demonstrate that the MEMS unit can be successfully operated by the thermal energy derived from a solar pond. This paper presents a brief description of test facilities, test procedure, and test data including production rate and energy consumption rate. These data and information will be very useful for improving the overall thermodynamic efficiency and economics of solar pond coupled MEMS desalination, as well as for thermal desalination using other solar options and/or waste heat.