Multi-objective optimization for the best possible thermal, electrical and overall energy performance of a novel perforated-type regenerative evaporative humidifier

Abstract A perforated-type regenerative type evaporative humidifier is presented which has an innovative flow configuration. Such a flow configuration prevents the moist air from achieving quick saturation, and as a result, it maximizes the humidification capacity. A control volume formulation based mathematical model is developed which is simulated using nested numerical techniques having coupled boundary conditions. The system performance is gauged by three objective functions, namely humidification capacity, total electrical energy consumption, and efficiency factor. A detailed sensitivity analysis is carried out to report the system performance with respect to outdoor air conditions, geometric parameters, and operating conditions. Afterwards, an optimization study is conducted for 11 different climatic zones all around the world. An optimized humidification capacity of ∼32 g water vapor /min, energy consumption of 2.1 kW, and an efficiency factor of ∼40% is reported for the proposed configuration for dry climatic zone which is 64%, 11%, and 26% more than a direct-contact evaporative humidifier respectively. It is also found that the optimal ranges for channel length, channel width, channel height, and water temperature, are 900–1000 mm, 55–60 cm, 7–8 mm, and 60–70 °C, respectively.