Parametric investigation of a counter-flow heat and mass exchanger based on Maisotsenko cycle

The performance of a dew-point cooler is analyzed in terms of various parameters including dew point and wet bulb effectiveness. An experimental set-up of a counter-flow heat and mass exchanger based on Maisotsenko cycle evaporation technique is established. The set-up consists of 8 dry channels made of aluminum sheets and 7 wet channels made of kraft paper. Experimental analysis is performed under wide range of operating parameters including air absolute humidity: 12.7 g/kg to 18 g/kg, air temperature 20 to 55°C , and inlet velocities 0.88 to 1.50 m/s. The results indicate that appreciably higher value of dew-point and the wet-bulb effectiveness can be achieved ranging up to a maximum of 93% and to 130%, respectively, at various inlet air conditions. Apart from the ambient air conditions, influence of amount of air diversion to wet side of channel is also studied. It is observed that this design feature of heat and mass exchanger can lead to a substantial increase of dew-point and wet-bulb effectiveness. By varying the inlet to wet side air ratio, a suitable limit of the quantity of inlet air diversion to working side is also suggested.