Theoretical and experimental analysis of the thermodynamic and economic performance for a packed bed humidifier

Abstract

In this paper, the thermodynamic and economic performance of the humidifier, with a wire mesh corrugated packing, is investigated and evaluated with the defined evaluation criteria experimentally and theoretically. In view of the humidification characteristics of packings, the mathematical models based on mass and energy balance are established. Performance of the packed bed humidifier, evaluated by the unit humidification capacity of volume (UHCV) and the unit humidification capacity of cost (UHCC), is first studied experimentally with fixed packing volume. Moreover, the parametric analysis of the humidification performance is achieved. The maximum values obtained simultaneously from the experiment present as 3.82 × 10−2 kgs−1 m−3 for the UHCV and 12.74 kg$−1 for the UHCC, as the liquid–gas ratio is 2 and the inlet water temperature is 90 °C. The simulation results illustrate that a peak point appears separately at mr = 0.5 for the UHCV and mr = 3 for the UHCC with the increase of liquid-gas ratio. It is also found that a higher value of the inlet air and water temperature, as well as the wet-bulb temperature of inlet humid air, can enhance the UHCV and UHCC in varying extents, while the inlet relative humidity has a reverse influence on them. Furthermore, it is observed that the effects of the specific surface area on the UHCV and UHCC are contradictory, with a best thermodynamic performance of 43.3 × 10−2 kgs−1 m−3, while the maximum economic value presents as 13.3 kg$−1.