Experimental investigation on the humidification parameters of the reciprocating multistage evaporative Cooler-A novel approach

Humidification-dehumidification technology is one of the most economical techniques to fulfill cooling needs. The current work focuses on designing and constructing a novel reciprocating packing humidification system, where four packings are placed in four different slots and operated by a cam follower mechanism. Inlet operating parameters such as air velocity and camshaft rotation are varied to determine the influence on the outlet parameters such as energy conversion rate, energy conversion factor, humidification efficiency, and specific cooling capacity. The reciprocating multistage evaporative cooler performs better than the single-stage cooler with superior values for the performance parameters. With the increase in the camshaft speed, there is a reduction in the energy conversion factor (ECF), humidification efficiency (HE), and evaporation rate (ER). An increase in air velocity increases ER, ECF and decreases HE. The highest humidification efficiency is 72.6%, and the ECF achieved is 2.9, corresponding to an air velocity of 5.6 m/s and a camshaft speed of 10 rpm. Comparison with conventional VCR-based cooling techniques reveals that 7% of energy can be saved using a multistage evaporating cooling device. Sensitivity analysis reveals that the air flow rate is more significant than the camshaft rpm influencing the output responses. Operating parameters have been optimized to attain enhanced performance from the multistage reciprocating cooler. The results indicated that maintaining the air velocity of 5.3–6 m/s and the camshaft speed of 16–18 rpm improves the overall performance of the evaporative cooler with reasonable energy consumption.