Papers by Dr. Hayder Al-Madhhachi
The key objective of this study is to analyse the heat transfer processes involved in the evapora... more The key objective of this study is to analyse the heat transfer processes involved in the evaporation and condensation of water in a water distillation system employing a thermoelectric module. This analysis can help to increase the water production and to enhance the system performance. For the analysis, a water distillation unit prototype integrated with a thermoelectric module was designed and fabricated. A theoretical model is developed to study the effect of the heat added, transferred and removed, in forced convection and laminar flow, during the evaporation and condensation processes. The thermoelectric module is used to convert electricity into heat under Peltier effect and control precisely the absorbed and released heat at the cold and hot sides of the module, respectively. Temperatures of water, vapour, condenser, cold and hot sides of the thermoelectric module and water production have been measured experimentally under steady state operation. The theoretical and experimental water production were found to be in agreement. The amount of heat that needs to be evaporated from water-vapour interface and transferred through the condenser surface to the thermoelectric module is crucial for the design and optimization of distillation systems.
In this study, mathematical calculations developed through water-vapour phase-change theory is us... more In this study, mathematical calculations developed through water-vapour phase-change theory is used to interpret the processes involved in the fresh water production of a thermoelectric distillation system. The rate of water production depends on various parameters of vaporization phenomena such as water and vapour temperatures, pressure, specific volume, heat capacity and water-vapour surface area. The water-vapour surface area is constant 10 x 10 cm 2 , the initial depth of the sample water is 3 cm and the air occupies the 500 cm 3 volume inside the chamber. The volume and the mass of vapour and water at water-vapour interface are calculated through one hour of the system operation. The temperatures of the system components, humidity and water production of the thermoelectric distillation system are measured. As a result, an increase in the temperature of water and hot side of the thermoelectric module leads to an increase in the water production by increasing the vapour formation at atmospheric pressure. After one hour of system operation, the water production reaches 34.5 mL and the humidity inside the chamber increases from 51 % to 74 %. The results also show the distillation ratio is 11.5%. The mathematical calculations validate the experimental data with reasonable agreement.
I. Abstract— In this paper, a thermal model has been developed for a water distillation system wh... more I. Abstract— 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/m 2 .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.
An efficient thermoelectric distillation system has been designed and constructed for production ... more An efficient thermoelectric distillation system has been designed and constructed for production of drinkable water. The unique design of this system is to use the heat from hot side of the thermoelectric module for water evaporation and the cold side for vapour condensation simultaneously. This novel design significantly reduces energy consumption and improves the system performance. The results of experiments show that the average water production is 28.5 mL/h with a specific energy consumption of 0.00114 kW h/mL in an evaporation chamber filled with 10 Â 10 Â 30 mm 3 of water. This is significantly lower than the energy consumption required by other existing thermoelectric distillation systems. The results also show that a maximum temperature difference between the hot and cold side of the ther-moelectric module is 42.3 °C, which led to temperature increases of 26.4 °C and 8.4 °C in water and vapour, respectively.
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Papers by Dr. Hayder Al-Madhhachi