Analysis and optimization of LT-MED system powered by an innovative CSP plant

Abstract

The access to drinking water is an increasing problem in the World in many geographical areas. The desalination of seawater is the main source to provide fresh water. The thermal desalination systems such as Low Temperature Multi-Effect Distillation (LT-MED) have gone through many stages of development to increase the energy efficiency of this system: this technology uses steam as part of its process to produce fresh water. Some improvements on the thermal desalination processes have resulted in less energy consumption. In order to further increase the energy efficiency in the desalination plants, renewable energy sources should be considered and evaluated in order to satisfy the worldwide demand of this technology. This paper presents an LT-MED system integrated with a novel Parabolic Trough Concentrated Solar Power (PT-CSP) plant whose reference cycle is called DEC, Discrete Ericsson Cycle which uses air as heat transfer fluid. This study explores the use of the waste heat in CSP-DEC plant to feed an LT-MED technology. It also discusses the plant layouts and performances of CSP-DEC+LT-MED plant. Because CSP-DEC can perform steam supply for LT-MED with less affecting on the electricity generation efficiency, CSP-DEC can optimize to lower energy loss than conventional CSP, while still producing larger quantity of fresh water.