Evaluation of the convection heat transfer coefficient in a thermoelectric distillation system

In this paper, a thermal model has been developed for a water distillation system which uses a thermoelectric module. The thermoelectric module cools a heat exchanger and extracts the latent heat of condensation from the water vapour at the cold side, releasing heat at the hot side to supplement the water heating. It is important to take into account the temperature distribution and the heat transfer of the thermoelectric distillation system to enhance the thermal performance. The model shows that the rate of water condensation is dependent upon the cold side temperature of the thermoelectric module, vapour temperature, geometry of the heat exchanger and the convection heat transfer coefficient of the heat exchanger at the cold side. The thermal model is used to analyses the experimental data of the thermoelectric distillation system. The results shows that the local convection heat transfer coefficient is 8 W/m2.K. Measurements of the distilled water show that the produced water has similar quality to the tap water in terms of PH, total dissolved solids and electrical conductivity values.