Numerical simulation and parametric study of effective parameters in a thermoelectric dehumidifier with cooled plate using the Peltier effect

The humid airflow condensation process on thermoelectric cooled flat plate is numerically investigated and analyzed in this study. A two-dimensional domain over a constant-temperature flat plate is modeled, with inlet air at specified humidity and temperature. Both the inlet conditions and plate temperature are systematically varied to identify the combination that affecting the condensation, which plays a crucial role in enhancing the design of thermoelectric atmospheric water generators. A mixture phase-change model was employed to simulate condensation over the cooled plate, with emphasis on the detrimental effect of surface ice formation on the process. Numerical results have been verified with the experimental data that was taken from the laboratory test facility which showed a discrepancy of approximately 10%. Effect of wall temperature, inlet humid air temperature, air flow velocity, relative humidity and plate length on the rate of condensation and generated water was analyzed in detail. Results indicated that increasing the relative humidity from 60% to 90% tripled the condensation rate. Conversely, increasing the inlet airflow velocity from 3 m/s to 15 m/s reduced the dehumidification rate to approximately 25% of its initial value. The study found that to achieve the best possible dehumidification performance and avoid ice formation in the thermoelectric dehumidification systems, precise control of thermal parameters is required. Specifically, by lowering the thermoelectric plate temperature from 270 K to 240 K, the rate of condensation increases by a factor of three as the driving force for condensation was increased. additionally, a tripling of plate length brought increasing in water yield by six times. And crucially, the study outlined the operational limits to avoid freezing, showing that ice forms when the plate temperature drops below 240 K, the inlet velocity drops below 3 m/s, or the air temperature drops below 290 K.