Solar Thermal-Driven Multiple-Effect Thermosyphon Distillation System for Waste Water Treatment

Abstract

A solar thermal-driven multiple-effect thermosyphon distillation (METD) system is proposed for waste-water treatment. The METD system consists of a series of cascaded thermosyphons that are connected by embedding the condenser section of each thermosyphon in the evaporator section of the following device. The input thermal energy is supplied by a solar collector integrated with a latent heat thermal energy storage unit. A thermal network model is developed to predict the heat transfer rates through the METD system and distilled water production rates. METD systems with various number of effects and hot end temperatures are investigated. It is found that the ratio of distilled water production to the input thermal energy increases by increasing the number of effects with no dependence on the hot end temperature. Quantitatively, a METD system with 5 effects can produce 11 kg of fresh water per hour with an input heat of 1.4 kW.