Application of novel chemical regimen in a thermal power plants’ cooling tower

The effect of chemical regimen on the corrosion and sedimentation rate of cooling tower of thermal power plant is investigated here. The subjected power plant has four wet cooling towers and the quality of raw water (well water) decreases drastically in recent years. Therefore, the clarifier process is incapable to provide suitable soft water. As a result, controlling corrosion and sedimentation with the applied chemical regimen is impossible due to the high alkalinity and hardness level of clarified water. Considering the lack of clarifier efficiency, a chemical regimen is proposed based on the elimination of clarifier processes and use of anti-corrosions, antiscalants and organic biocides. For this purpose, corrosion and scale coupon, microbial monitoring, chemical and physicochemical water analysis are applied to evaluate the effect of proposed regimen on the condenser and cooling tower performance. All mentioned parameters are examined in both main (new regimen) and control (previous regimen) unit. In both regimens, the bleach injection is performed continuously. However, TBC level is obtained 10 3 -10 4 and 0–100 cfu/ml for previous and new regimen, respectively. The corrosion rate of the condenser is reduced by 6 times with application of anti-corrosion. Furthermore, destruction rate of wooden structure of cooling tower in previous regimen is 1.5 times higher than new regimen. Moreover, the sedimentation rate of routine regimen is 6 times higher than new regimen due to use of antiscalants. The overall results prove that corrosion and sedimentation rates decrease dramatically with the elimination of clarifier processes and applying new regimen. ● Corrosion and sedimentation of cooling tower are evaluated as function of chemical regimen. ● Clarifier process is incapable to provide soft water due to high alkalinity and hardness level. ● Novel chemical regimen is proposed based on the elimination of clarifier processes and applying new material. ● Anti-corrosions, antiscalants and organic biocides are applied to improve the efficiency of regimen. ● Corrosion, sedimentation, microbial factors are reduced by 6, 6 and 100 times, respectively in new regimen.