Integrated Thermoelectric-Multi-Stage Flash distillation

This work presents a fully electrically powered desalination configuration that integrates a thermoelectric distiller (TED) with a once-through multi-stage flash (MSF) system of 24 stages. The hot side of thermoelectric modules (TEMs) provides the heating effect (Q_h) for boiling and for heating the TED and MSF feed streams, while the cold side condenses vapor generated inside TED. In the proposed sequence, the MSF feed is first preheated progressively through the MSF stages from ambient temperature to 85 °C, then heated in TED to the saturation temperature of the first MSF stage (100 °C) before entering MSF. A compact heat exchanger recovers sensible heat from the TED distillate to preheat the TED feed. Numerical simulations show clear trends with input current. Increasing current from 2 A to 7 A raises total water production from 1.46 to 13.2 kg/h, and the gained output ratio (GOR) improves from 1.68 to 3.1. The MSF share of total production (R_m,MSF) increases from 59% to over 92%. Conversely, TEMs heating coefficient of performance (COP_h) decreases from 3.2 to 1.2, and the specific energy consumption (SEC) rises from 120 to 160 kWh/m³. The overall recovery ratio declines from 16.2% to 11% as current increases. Because the system requires only DC electrical input, it can be powered by photovoltaic sources, enabling compact, scalable, and sustainable desalination.