A Novel Approach for Water Conservation and Plume Abatement in Mechanical Draft Cooling Towers

Abstract

While the visible plume from a cooling tower is not a pollutant, it can affect the surrounding environment. Moreover, the accompanied evaporation loss has a great potential for wastewater recovery. In the present study, a novel coupling technology for water conservation and plume abatement was proposed, and its feasibility was verified by using thermodynamic analysis. A surface-type heat exchanger was designed and a thermodynamic calculation model was established. Next, based on the principle of “no plume,” the effect of the number of heat exchanger units (N) and the circulating water volume (G) on the water conservation and plume abatement was evaluated under design condition. Results showed that the optimized parameters for the operation of the cooling towers were N = 8 and G < 3000 m3/h, which have a good effect on water conservation and plume abatement. Furthermore, as per the condensation calculation model, the average water conservation amount was 1.105 kg/s and the annual water conservation amount reached 2.8641 × 107 kg.

Cooling tower plume abatement and plume modeling: a review

“…Recently Wang et al [151] evaluated the plume abatement and water conservation performances of the Air2Air TM heat exchanger. They found that water savings increased significantly under ambient conditions of low temperature and high RH.…”

“…The atmosphere can be either stable ( N 2 > 0 ), neutral ( N 2 = 0 ) or unstable ( N 2 < 0). [144,148,149] and solar collectors [150] HVAC cooling towers, suitable for high relative humidity Enhanced mixing using static and non-static mixers Deflecting surfaces [21,71,129], vortex generators [123,124] and stirring mixing devices [107] Cooling towers (including back-to-back towers) with Level 2 plume abatement criterion [9] Coaxial plume mixing Hybrid (crossflow) towers [57,79,80,93] Cooling towers designed with Level 1 plume abatement criterion [9] Cooling the hot, humid air Water vapor channel [114], thermosyphon system [99], air-toair heat exchangers [58,94,151] Preferred in large back-to-back towers and in arid regions; good functionality even in freezing weather conditions (condensed) and dry (uncondensed) plumes under different atmospheric conditions. Later Wigley [152] included the dynamics of droplet growth in the condensation phase.…”