Optimization on Microbial Anti-Scaling and Corrosion Inhibition Technology for Low Alkalinity and Low Hardness Circulating Cooling Water in Thermal Power Plants

Abstract

This paper analyzed the potential effectiveness of microbial anti-scaling and corrosion inhibition technology for low alkalinity and low hardness circulating cooling water in thermal power plants and used response surface models to study the effects and optimal conditions of key technical parameters. The results showed that when the nutrient solution dosage, bacterial agent dosage and aeration rate were set at 0.1-0.3 ‰, 0.1-0.5 ‰, and 1-3 L/min, respectively, the calcium hardness, corrosion rate of brass and stainless steel 304 in the water could be controlled within 9.77-15.30 mmol/L, 0.77-6.58 μm/a, and 1.20-4.50 μm/a, respectively. The variance analysis results indicated that the response surface linear model was the most suitable for evaluating the effects of key operation parameters on the application efficiency of the technology. The obtained model furtherly revealed that the nutrient solution dosage and bacterial agent dosage were extremely significant explanatory variable factors affecting the application of microbial technology in inhibition and corrosion control (P < 0.01). Still, the aeration rate did not reach a significant effect (P > 0.05). Based on the regression equation of actual factors, the study further revealed through the hill climbing algorithm that the optimal comprehensive effect of microbial technology in inhibition and corrosion control was achieved when the nutrient solution dosage, bacterial agent dosage, and aeration rate were set at 0.3‰, 0.5‰, and 1 L/min, respectively.